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Find the sum and difference between a pair of two-digit numbers. Now find the sum and difference between the sum and difference! What happens?
This challenge focuses on finding the sum and difference of pairs of two-digit numbers.
Try adding together the dates of all the days in one week. Now multiply the first date by 7 and add 21. Can you explain what happens?
This task follows on from Build it Up and takes the ideas into three dimensions!
In this calculation, the box represents a missing digit. What could the digit be? What would the solution be in each case?
Can you find all the ways to get 15 at the top of this triangle of numbers? Many opportunities to work in different ways.
This challenge is about finding the difference between numbers which have the same tens digit.
Ben’s class were cutting up number tracks. First they cut them into twos and added up the numbers on each piece. What patterns could they see?
This challenge, written for the Young Mathematicians' Award, invites you to explore 'centred squares'.
We can arrange dots in a similar way to the 5 on a dice and they usually sit quite well into a rectangular shape. How many altogether in this 3 by 5? What happens for other sizes?
Ben and his mum are planting garlic. Use the interactivity to help you find out how many cloves of garlic they might have had.
Only one side of a two-slice toaster is working. What is the quickest way to toast both sides of three slices of bread?
Frances and Rishi were given a bag of lollies. They shared them out evenly and had one left over. How many lollies could there have been in the bag?
Place the numbers from 1 to 9 in the squares below so that the difference between joined squares is odd. How many different ways can you do this?
This problem challenges you to find out how many odd numbers there are between pairs of numbers. Can you find a pair of numbers that has four odds between them?
In a Magic Square all the rows, columns and diagonals add to the 'Magic Constant'. How would you change the magic constant of this square?
Sweets are given out to party-goers in a particular way. Investigate the total number of sweets received by people sitting in different positions.
Watch this animation. What do you notice? What happens when you try more or fewer cubes in a bundle?
Find the sum of all three-digit numbers each of whose digits is odd.
Try out this number trick. What happens with different starting numbers? What do you notice?
Tom and Ben visited Numberland. Use the maps to work out the number of points each of their routes scores.
Put the numbers 1, 2, 3, 4, 5, 6 into the squares so that the numbers on each circle add up to the same amount. Can you find the rule for giving another set of six numbers?
How many ways can you find to do up all four buttons on my coat? How about if I had five buttons? Six ...?
In this problem we are looking at sets of parallel sticks that cross each other. What is the least number of crossings you can make? And the greatest?
Can you see why 2 by 2 could be 5? Can you predict what 2 by 10 will be?
An investigation that gives you the opportunity to make and justify predictions.
If there are 3 squares in the ring, can you place three different numbers in them so that their differences are odd? Try with different numbers of squares around the ring. What do you notice?
What happens when you round these three-digit numbers to the nearest 100?
Can you put the numbers 1-5 in the V shape so that both 'arms' have the same total?
Two children made up a game as they walked along the garden paths. Can you find out their scores? Can you find some paths of your own?
Use your addition and subtraction skills, combined with some strategic thinking, to beat your partner at this game.
What can you say about these shapes? This problem challenges you to create shapes with different areas and perimeters.
Does this 'trick' for calculating multiples of 11 always work? Why or why not?
Watch the video of Fran re-ordering these number cards. What do you notice? Try it for yourself. What happens?
Are these statements relating to calculation and properties of shapes always true, sometimes true or never true?
Strike it Out game for an adult and child. Can you stop your partner from being able to go?
What happens if you join every second point on this circle? How about every third point? Try with different steps and see if you can predict what will happen.
Florence, Ethan and Alma have each added together two 'next-door' numbers. What is the same about their answers?
Are these statements relating to odd and even numbers always true, sometimes true or never true?
Can you make dice stairs using the rules stated? How do you know you have all the possible stairs?
This challenge encourages you to explore dividing a three-digit number by a single-digit number.
Here are two kinds of spirals for you to explore. What do you notice?
This challenge asks you to imagine a snake coiling on itself.
What happens when you round these numbers to the nearest whole number?
This activity focuses on rounding to the nearest 10.
How many different journeys could you make if you were going to visit four stations in this network? How about if there were five stations? Can you predict the number of journeys for seven stations?
In this game for two players, the idea is to take it in turns to choose 1, 3, 5 or 7. The winner is the first to make the total 37.
In how many different ways can you break up a stick of 7 interlocking cubes? Now try with a stick of 8 cubes and a stick of 6 cubes.
Can you dissect an equilateral triangle into 6 smaller ones? What number of smaller equilateral triangles is it NOT possible to dissect a larger equilateral triangle into?
Take a look at the video of this trick. Can you perform it yourself? Why is this maths and not magic? | https://nrich.maths.org/public/leg.php?code=72&cl=1&cldcmpid=184 |
These squares have been made from Cuisenaire rods. Can you describe the pattern? What would the next square look like?
Can you continue this pattern of triangles and begin to predict how many sticks are used for each new "layer"?
Watch the video of Fran re-ordering these number cards. What do you notice? Try it for yourself. What happens?
Polygonal numbers are those that are arranged in shapes as they enlarge. Explore the polygonal numbers drawn here.
Sweets are given out to party-goers in a particular way. Investigate the total number of sweets received by people sitting in different positions.
This problem challenges you to find out how many odd numbers there are between pairs of numbers. Can you find a pair of numbers that has four odds between them?
Here are two kinds of spirals for you to explore. What do you notice?
Place the numbers from 1 to 9 in the squares below so that the difference between joined squares is odd. How many different ways can you do this?
In this calculation, the box represents a missing digit. What could the digit be? What would the solution be in each case?
Can you make dice stairs using the rules stated? How do you know you have all the possible stairs?
In how many different ways can you break up a stick of 7 interlocking cubes? Now try with a stick of 8 cubes and a stick of 6 cubes.
Think of a number, square it and subtract your starting number. Is the number you’re left with odd or even? How do the images help to explain this?
While we were sorting some papers we found 3 strange sheets which seemed to come from small books but there were page numbers at the foot of each page. Did the pages come from the same book?
Ben and his mum are planting garlic. Can you find out how many cloves of garlic they might have had?
Frances and Rishi were given a bag of lollies. They shared them out evenly and had one left over. How many lollies could there have been in the bag?
Take a counter and surround it by a ring of other counters that MUST touch two others. How many are needed?
Florence, Ethan and Alma have each added together two 'next-door' numbers. What is the same about their answers?
Can you dissect an equilateral triangle into 6 smaller ones? What number of smaller equilateral triangles is it NOT possible to dissect a larger equilateral triangle into?
What happens if you join every second point on this circle? How about every third point? Try with different steps and see if you can predict what will happen.
Can you work out how to win this game of Nim? Does it matter if you go first or second?
Stop the Clock game for an adult and child. How can you make sure you always win this game?
Only one side of a two-slice toaster is working. What is the quickest way to toast both sides of three slices of bread?
We can arrange dots in a similar way to the 5 on a dice and they usually sit quite well into a rectangular shape. How many altogether in this 3 by 5? What happens for other sizes?
Nim-7 game for an adult and child. Who will be the one to take the last counter?
In a Magic Square all the rows, columns and diagonals add to the 'Magic Constant'. How would you change the magic constant of this square?
What can you say about these shapes? This problem challenges you to create shapes with different areas and perimeters.
Two children made up a game as they walked along the garden paths. Can you find out their scores? Can you find some paths of your own?
Tom and Ben visited Numberland. Use the maps to work out the number of points each of their routes scores.
If there are 3 squares in the ring, can you place three different numbers in them so that their differences are odd? Try with different numbers of squares around the ring. What do you notice?
An investigation that gives you the opportunity to make and justify predictions.
How many ways can you find to do up all four buttons on my coat? How about if I had five buttons? Six ...?
How many different journeys could you make if you were going to visit four stations in this network? How about if there were five stations? Can you predict the number of journeys for seven stations?
This challenge encourages you to explore dividing a three-digit number by a single-digit number.
Compare the numbers of particular tiles in one or all of these three designs, inspired by the floor tiles of a church in Cambridge.
In this game for two players, the idea is to take it in turns to choose 1, 3, 5 or 7. The winner is the first to make the total 37.
Find the sum and difference between a pair of two-digit numbers. Now find the sum and difference between the sum and difference! What happens?
This challenge focuses on finding the sum and difference of pairs of two-digit numbers.
This activity focuses on rounding to the nearest 10.
What happens when you round these three-digit numbers to the nearest 100?
Can you put the numbers 1-5 in the V shape so that both 'arms' have the same total?
Watch this animation. What do you notice? What happens when you try more or fewer cubes in a bundle?
The NRICH team are always looking for new ways to engage teachers and pupils in problem solving. Here we explain the thinking behind maths trails.
Ben’s class were cutting up number tracks. First they cut them into twos and added up the numbers on each piece. What patterns could they see?
Take a look at the video of this trick. Can you perform it yourself? Why is this maths and not magic?
How can you arrange these 10 matches in four piles so that when you move one match from three of the piles into the fourth, you end up with the same arrangement?
A game for 2 players with similarities to NIM. Place one counter on each spot on the games board. Players take it is turns to remove 1 or 2 adjacent counters. The winner picks up the last counter.
Put the numbers 1, 2, 3, 4, 5, 6 into the squares so that the numbers on each circle add up to the same amount. Can you find the rule for giving another set of six numbers?
Are these statements always true, sometimes true or never true?
In each of the pictures the invitation is for you to: Count what you see. Identify how you think the pattern would continue.
Can you find all the ways to get 15 at the top of this triangle of numbers? Many opportunities to work in different ways. | https://nrich.maths.org/public/topic.php?code=72&cl=1&cldcmpid=7233 |
Multiplication is an arithmetic operation that finds the sum of two or more numerical results by repeating the same number x times. Symbols like an asterisk, double-dot, and the word “times” are used for multiplication.
There are many factors that can influence the value of any multiplication. The first factor is the type of numbers that you are dealing with (number 1, being the only major one). Next, you need to consider how many pieces you are dealing with. The second is the area between it (and the next number x). The fraction is simply the difference between the first number (or the second) and the second (or the third).
Let’s review the examples of multiplication with the denominator in this equation: 3×3 = (add the number 3, to the original number, and get the answer), x. The numerator (the first factor) is the type of numbers involved. The space between the first and second numbers is the second factor. The third factor is the pattern the repeating addition will follow, (i.e., (multiply x) where x is the answer).
If you are just beggining with multiplication probably you are going to study it by memorizacion. This can be a bit boring. However, you can find multiple support sources online like nofusstutors.com/blog-posts/multiplication-chart to make this learning process easier and more interesting. Once you have perfected this subject you will be ready to face more difficult math problems that in long term will allow you to get a better understanding of the world and find solutions using the multiple tools that maths offer.
This concludes the discussion of multiplication with basic graphical expressions. You can find more advanced articles on the topic of multiplication. For now, you can continue your research on multiplication by using graphic expressions. Feel free to submit any questions or comments about this article. I would be delighted to hear any suggestions you may have! | https://kolocsolidaire.org/learning-maths-and-multiplication/ |
Problem: Let f(x) be the product of digits of a number. Given L and R, find the number of values of ‘i’ such that L <= i <= R and f(i) is even.
Pre-Requisites : None
Explanation :
We have to find the count of such numbers, between 2 given numbers, whose product of digits is even. Any number, in which any one digit is even, will come in this category. We will find all those numbers whose product of digits is odd and subtract them from total numbers between two given numbers. We will calculate required numbers from 1 to first number and lets call it num1, then from 1 to second number and lets call it num2 , then num2-num1 will be the answer.
Suppose we consider any n digit number. Then the number of numbers with exactly n digits and all digits odd will be 5 raised to power n. So, the number of numbers from 1 digit to n digits with all digits odd will be sum of all powers of 5 raised to power 1 upto n ie. 5^1 + 5^2 + 5^3 +…….+ 5^n.
The above formula of 5 gives the ans as 999..9(n times). But what about the case when the number is neither the smallest, nor the largest n digit number.
So if we are a general n digit number, then we will use formula to calculate the required number of numbers upto n-1 digits and use the following approach to calculate the number of n digits numbers, smaller than given number, for which product of digits is odd.
The number of such numbers will be equal to sum of the numbers of product of half of corresponding digit and 5^ [length-position-1] and this digit will be from left digit to right digit. However, this process will stop when we encounter an even digit because from there we will not get any number where all digits will be odd.
Pseudocode :
sum = power = 0 for i = 1 to 10 : power[i] = power[i-1] * 5 sum[i] = sum[i-1] + power[i] //dig1 is string form of first number. //dig2 is string form of second number. //n1 stores the number of numbers whose product of digits is odd. //length1 is length of first string. //length2 is length of second string. n1 = sum[length1-1] //Calculating upto length1-1 digits for j = 0 to length1: n1 = n1 + dig1[j]/2 * power[length1-j-1] // n1 gives the number of numbers with all digits odd from 1 to dig1.
Do the same for second number.
Subtract n1 from n2 and subtract this result from the difference between the given 2 numbers to obtain the required answer.
Let us take an example. Suppose we have to calculate till 57981. So, from 10000 to 50000, our counting will be only from 10000 to 19999 and 30000 to 39999, so and the number will be equal to same which we found for 4-digit numbers. Then we will shift our counter from 5 to 7 in our number 57981. Now, our target will be from 1000 to 1999, 3000 to 3999, 5000 to 5999, and our answer will be same as we found for 3 digit numbers. Process terminates as we encounter 8 as after it, no more numbers with all digits odd. | http://pag.iitr.ac.in/blog/spoj-geekount |
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Here are some arrangements of circles. How many circles would I need to make the next size up for each? Can you create your own arrangement and investigate the number of circles it needs?
Think of a number, square it and subtract your starting number. Is the number you’re left with odd or even? How do the images help to explain this?
In each of the pictures the invitation is for you to: Count what you see. Identify how you think the pattern would continue.
Take a counter and surround it by a ring of other counters that
MUST touch two others. How many are needed?
These squares have been made from Cuisenaire rods. Can you describe
the pattern? What would the next square look like?
How can you arrange these 10 matches in four piles so that when you
move one match from three of the piles into the fourth, you end up
with the same arrangement?
Watch this film carefully. Can you find a general rule for
explaining when the dot will be this same distance from the
horizontal axis?
Polygonal numbers are those that are arranged in shapes as they enlarge. Explore the polygonal numbers drawn here.
While we were sorting some papers we found 3 strange sheets which
seemed to come from small books but there were page numbers at the
foot of each page. Did the pages come from the same book?
What would be the smallest number of moves needed to move a Knight
from a chess set from one corner to the opposite corner of a 99 by
99 square board?
Can you continue this pattern of triangles and begin to predict how many sticks are used for each new "layer"?
Can you see why 2 by 2 could be 5? Can you predict what 2 by 10
will be?
Use the interactivity to investigate what kinds of triangles can be
drawn on peg boards with different numbers of pegs.
Sweets are given out to party-goers in a particular way. Investigate the total number of sweets received by people sitting in different positions.
This challenge focuses on finding the sum and difference of pairs of two-digit numbers.
Triangle numbers can be represented by a triangular array of squares. What do you notice about the sum of identical triangle numbers?
This challenge, written for the Young Mathematicians' Award, invites you to explore 'centred squares'.
Imagine starting with one yellow cube and covering it all over with
a single layer of red cubes, and then covering that cube with a
layer of blue cubes. How many red and blue cubes would you need?
Place the numbers from 1 to 9 in the squares below so that the difference between joined squares is odd. How many different ways can you do this?
If you can copy a network without lifting your pen off the paper and without drawing any line twice, then it is traversable.
Decide which of these diagrams are traversable.
Find out what a "fault-free" rectangle is and try to make some of
your own.
Use the animation to help you work out how many lines are needed to draw mystic roses of different sizes.
Only one side of a two-slice toaster is working. What is the
quickest way to toast both sides of three slices of bread?
Find the sum and difference between a pair of two-digit numbers. Now find the sum and difference between the sum and difference! What happens?
How could Penny, Tom and Matthew work out how many chocolates there
are in different sized boxes?
How many ways can you find to do up all four buttons on my coat? How about if I had five buttons? Six ...?
Can you find all the ways to get 15 at the top of this triangle of numbers?
This task follows on from Build it Up and takes the ideas into three dimensions!
Three circles have a maximum of six intersections with each other.
What is the maximum number of intersections that a hundred circles
could have?
Can you make dice stairs using the rules stated? How do you know you have all the possible stairs?
Compare the numbers of particular tiles in one or all of these
three designs, inspired by the floor tiles of a church in
Cambridge.
What would you get if you continued this sequence of fraction sums?
1/2 + 2/1 =
2/3 + 3/2 =
3/4 + 4/3 =
How many centimetres of rope will I need to make another mat just
like the one I have here?
In how many different ways can you break up a stick of 7 interlocking cubes? Now try with a stick of 8 cubes and a stick of 6 cubes.
Ben’s class were cutting up number tracks. First they cut them into twos and added up the numbers on each piece. What patterns could they see?
Draw a square. A second square of the same size slides around the
first always maintaining contact and keeping the same orientation.
How far does the dot travel?
This article for teachers describes several games, found on the
site, all of which have a related structure that can be used to
develop the skills of strategic planning.
Can you put the numbers 1-5 in the V shape so that both 'arms' have the same total?
Square numbers can be represented as the sum of consecutive odd
numbers. What is the sum of 1 + 3 + ..... + 149 + 151 + 153?
The aim of the game is to slide the green square from the top right
hand corner to the bottom left hand corner in the least number of
moves.
An investigation that gives you the opportunity to make and justify
predictions.
Choose a couple of the sequences. Try to picture how to make the next, and the next, and the next... Can you describe your reasoning?
What happens if you join every second point on this circle? How
about every third point? Try with different steps and see if you
can predict what will happen.
How many different journeys could you make if you were going to visit four stations in this network? How about if there were five stations? Can you predict the number of journeys for seven stations?
We can arrange dots in a similar way to the 5 on a dice and they
usually sit quite well into a rectangular shape. How many
altogether in this 3 by 5? What happens for other sizes?
In a Magic Square all the rows, columns and diagonals add to the 'Magic Constant'. How would you change the magic constant of this square?
Explore the effect of reflecting in two intersecting mirror lines.
Put the numbers 1, 2, 3, 4, 5, 6 into the squares so that the
numbers on each circle add up to the same amount. Can you find the
rule for giving another set of six numbers?
A 2 by 3 rectangle contains 8 squares and a 3 by 4 rectangle
contains 20 squares. What size rectangle(s) contain(s) exactly 100
squares? Can you find them all?
Try entering different sets of numbers in the number pyramids. How does the total at the top change? | http://nrich.maths.org/public/leg.php?code=72&cl=2&cldcmpid=502 |
Ben’s class were cutting up number tracks. First they cut them into twos and added up the numbers on each piece. What patterns could they see?
Try adding together the dates of all the days in one week. Now multiply the first date by 7 and add 21. Can you explain what happens?
Try out this number trick. What happens with different starting numbers? What do you notice?
This challenge focuses on finding the sum and difference of pairs of two-digit numbers.
In a Magic Square all the rows, columns and diagonals add to the 'Magic Constant'. How would you change the magic constant of this square?
Can you see why 2 by 2 could be 5? Can you predict what 2 by 10 will be?
Find the sum and difference between a pair of two-digit numbers. Now find the sum and difference between the sum and difference! What happens?
This task follows on from Build it Up and takes the ideas into three dimensions!
Find the sum of all three-digit numbers each of whose digits is odd.
How many ways can you find to do up all four buttons on my coat? How about if I had five buttons? Six ...?
Tom and Ben visited Numberland. Use the maps to work out the number of points each of their routes scores.
Put the numbers 1, 2, 3, 4, 5, 6 into the squares so that the numbers on each circle add up to the same amount. Can you find the rule for giving another set of six numbers?
Strike it Out game for an adult and child. Can you stop your partner from being able to go?
Does this 'trick' for calculating multiples of 11 always work? Why or why not?
Use your addition and subtraction skills, combined with some strategic thinking, to beat your partner at this game.
Only one side of a two-slice toaster is working. What is the quickest way to toast both sides of three slices of bread?
Can you make dice stairs using the rules stated? How do you know you have all the possible stairs?
This challenge, written for the Young Mathematicians' Award, invites you to explore 'centred squares'.
Can you find all the ways to get 15 at the top of this triangle of numbers? Many opportunities to work in different ways.
Place the numbers from 1 to 9 in the squares below so that the difference between joined squares is odd. How many different ways can you do this?
We can arrange dots in a similar way to the 5 on a dice and they usually sit quite well into a rectangular shape. How many altogether in this 3 by 5? What happens for other sizes?
Watch this animation. What do you notice? What happens when you try more or fewer cubes in a bundle?
Can you put the numbers 1-5 in the V shape so that both 'arms' have the same total?
An investigation that gives you the opportunity to make and justify predictions.
Investigate the sum of the numbers on the top and bottom faces of a line of three dice. What do you notice?
While we were sorting some papers we found 3 strange sheets which seemed to come from small books but there were page numbers at the foot of each page. Did the pages come from the same book?
Sweets are given out to party-goers in a particular way. Investigate the total number of sweets received by people sitting in different positions.
What can you say about these shapes? This problem challenges you to create shapes with different areas and perimeters.
In this problem we are looking at sets of parallel sticks that cross each other. What is the least number of crossings you can make? And the greatest?
Polygonal numbers are those that are arranged in shapes as they enlarge. Explore the polygonal numbers drawn here.
These squares have been made from Cuisenaire rods. Can you describe the pattern? What would the next square look like?
This activity involves rounding four-digit numbers to the nearest thousand.
In this game for two players, the idea is to take it in turns to choose 1, 3, 5 or 7. The winner is the first to make the total 37.
The number of plants in Mr McGregor's magic potting shed increases overnight. He'd like to put the same number of plants in each of his gardens, planting one garden each day. How can he do it?
Investigate the different ways that fifteen schools could have given money in a charity fundraiser.
You can work out the number someone else is thinking of as follows. Ask a friend to think of any natural number less than 100. Then ask them to tell you the remainders when this number is divided by. . . .
What happens if you join every second point on this circle? How about every third point? Try with different steps and see if you can predict what will happen.
This challenge encourages you to explore dividing a three-digit number by a single-digit number.
Use two dice to generate two numbers with one decimal place. What happens when you round these numbers to the nearest whole number?
What happens when you round these three-digit numbers to the nearest 100?
What happens when you round these numbers to the nearest whole number?
Can you dissect an equilateral triangle into 6 smaller ones? What number of smaller equilateral triangles is it NOT possible to dissect a larger equilateral triangle into?
Find a route from the outside to the inside of this square, stepping on as many tiles as possible.
A collection of games on the NIM theme
Jo has three numbers which she adds together in pairs. When she does this she has three different totals: 11, 17 and 22 What are the three numbers Jo had to start with?”
Take a look at the video of this trick. Can you perform it yourself? Why is this maths and not magic?
Are these statements always true, sometimes true or never true?
Try entering different sets of numbers in the number pyramids. How does the total at the top change?
Use the interactivity to investigate what kinds of triangles can be drawn on peg boards with different numbers of pegs.
This article for primary teachers discusses how we can help learners generalise and prove, using NRICH tasks as examples. | https://nrich.maths.org/public/topic.php?code=72&cl=2&cldcmpid=1136 |
Binary vs. Decimal Measurements
One of the more difficult problems you will face when working with computer hardware, especially hard drives, is the two different measurement definitions or terms used to calculate drive capacity. Capacity measurements are usually expressed in kilobytes (thousands of bytes), in megabytes (millions of bytes), or gigabytes (billions of bytes), however, due to a mathematical coincidence there are two different meanings for each of these measures.
Computers are digital, and with that store data using binary numbers, or powers of two, although we are accustomed to using decimal numbers, expressed as powers of ten. As it turns out, two to the tenth power, 2^10, is 1,024, which is very close in value to 1,000 (10^3). Similarly, 2^20 is 1,048,576, which is approximately 1,000,000 (10^6), and 2^30 is 1,073,741,824, close to 1,000,000,000 (10^9). As computer development became more prominent and binary numbers began to be used on a regular basis, computer scientists took note of this similarity and began using the abbreviations normally associated with decimal numbers, and applied them to binary numbers. This led to 2^10 being given the prefix “kilo”, 2^20 given the prefix “mega”, and 2^30 referred to as “giga”.
This shorthand reference works well when used between technicians who regularly work in computer development, as they know what they are referring to, (and no one else really cares). However, when computers entered the mainstream, the dual reference began leading to quite a bit of confusion and inconsistency. In many areas of development, only binary values are used. As an example, 64 MB of RAM memory always means 64 times 1,048,576 bytes, never 64,000,000. Lending confusion to this mess though, in some areas only decimal values are used such as when the term, “56K modem” works at a maximum speed of 56,000 bits per second, not 57,344.
It’s no secret that storage devices are the single largest area of confusion in this regard, as some drive manufacturers use the decimal method, while others use the binary method when advertising their drive capacities. Even some software companies play this game, with some software packages using binary megabytes and gigabytes, and others using decimal megabytes and gigabytes. If you are using smaller numbers, the difference between decimal and binary is rather insignificant, but as the numbers grow larger so does the disparity. As an example, there is only a 2.4% difference between a decimal and a binary kilobyte, but when you calculate a megabyte, this difference increases to approximately 5%. A gigabyte produces a difference of approximately 7.5%, which is a rather significant difference. Not too many years ago this difference, as it pertains to hard drives that is, wasn’t all that noticeable when drive manufacturers advertised the size of their drives in decimal format, and you partitioned and formatted your drive in binary. Today, however, people are beginning to notice the difference between the two measures. As an example, should you purchase an “80 GB” hard drive, in all probability it will partition and format to about 74.2 to 76.3 gigabytes. Don’t worry, there’s nothing wrong with the drive, it’s just that the manufacturer stated the 80 GB in decimal format, but Windows (MS-DOS) partitioned and formatted the disk in binary gigabytes. There are a few other issues with large hard drive capacities, but we’ll address those in the drive limitations and barriers section of this topic area.
Another issue of importance is that of converting between binary gigabytes and binary megabytes. Decimal gigabytes and megabytes differ by a factor of 1,000, however binary measurement differs by 1,024. So the same 80 GB hard disk is 80,000 MB in decimal terms, however the 76.3 binary gigabytes are equal to 78,131 binary megabytes (76.3 times 1,024).
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Figure 1:
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This is an example of a Windows 9x display of the capacity of an 8 GB hard disk drive.
Take note of the disparity between the number of bytes and
and GB values, which are obviously in binary format.
Although a bit off the subject of hard drives, but relevant nonetheless, is the issue of the mathematical differences in definitions of “mega” or “giga”. A classic example would be the PCI bus, which has a theoretical maximum bandwidth of 133.3 Mbytes/second as the result of the fact that it is 4 bytes wide and runs at 33.3 MHz. Unfortunately though, the “M” in “MHz” is 1,000,000, but the “M” in “Mbytes/second” is 1,048,576. Therefore, the bandwidth of the PCI bus is more properly stated as 127.2 Mbytes/second (4 times 33,333,333 divided by 1,048,576).
Even with all of this confusion, there appears to be some light at the end of the tunnel. The Institute for Electrical and Electronics Engineers (IEEE) has proposed an entirely new naming convention for binary numbers in an effort to eliminate some of this confusion. Under there proposal, when binary numbers are in use, the third and fourth letters in the prefix are changed to “bi”. As an example, “mega” becomes “mebi”. One megabyte would be 10^6 bytes, however one mebibyte would be 2^20 bytes and the abbreviation would become “1 MiB” instead of “1 MB”. Below you will find a table showing the decimal and binary values and their conversion values. While “bytes” are shown in this table, the prefix could apply to any unit of measure.
|
|
Decimal Name
|
|
Decimal Abbr.
|
|
Decimal Power
|
|
Decimal Value
|
|
Binary Name
|
|
Binary Abbr.
|
|
Binary Power
|
|
Binary Value
|
|
Kilobyte
|
|
kB
|
|
10^3
|
|
1,000
|
|
Kibibyte
|
|
kiB
|
|
2^10
|
|
1,024
|
|
Megabyte
|
|
MB
|
|
10^6
|
|
1,000,000
|
|
Mebibyte
|
|
MiB
|
|
2^20
|
|
1,048,576
|
|
Gigabyte
|
|
GB
|
|
10^9
|
|
1,000,000,000
|
|
Gibibyte
|
|
GiB
|
|
2^30
|
|
1,073,741,824
|
|
Terabyte
|
|
TB
|
|
10^12
|
|
1,000,000,000,000
|
|
Tebibyte
|
|
TiB
|
|
2^40
|
|
1,099,511,627,776
While it appears that no one is jumping on the bandwagon to accept this new standard, should you want to research this issue a little further, click here: International System of Units (SI) – Definitions of the SI Units: The Binary Prefixes. We have decided to wait and allow the industry as a whole make the switch before we decide to do so, in order to avoid even more confusion.
Notice: Windows® 95, Windows® 98, Windows® NT, Windows® 2000, Windows® XP and Microsoft® Office are registered trademarks or trademarks of the Microsoft Corporation.
All other trademarks are the property of their respective owners. | https://www.dewassoc.com/binary-vs-decimal-measurements/ |
DATE in Excel (Formula,Examples) | How to Use DATE Function?
How to Use DATE Function in Excel?
Often in excel, we do not get the exact date that we want; I mean the formatting of the date. The preferable date format for most of us is DD-MM-YYY.
Excel works on numbers and it will display according to the format we give. Let us look at the below simple examples.
Enter the number 43434 in excel and give the format as DD-MM-YYY.
Once the above format is given now look how excel show up that number.
Now give the format as [hh]:mm:ss and the display will be as per the below image.
So excel completely works on numbers and their formats.
By using DATE Function in Excel, we can create an accurate date. For example, =DATE (2018, 11, 14) would give the result as 14-11-2018.
The Formula of DATE function includes 3 arguments i.e. Year, Month, and Day.
Year: It is the mandatory parameter. A year is always a 4-digit number. Since it is number we need not to specify the number in any double quotes.
Month: This is also a mandatory parameter. A month should be a 2-digit number that can be supplied either directly to the cell reference or direct supply to the parameter.
Day: It is also a mandatory parameter. A day should be a 2-digit number.
This DATE Function in Excel is very simple easy to use. Let us now see how to use the DATE Function in Excel with the help of some examples.
From the below data create full date values. In the first column we have days, in the second column, we have a month and in the third column, we have a year. We need to combine these three columns and create a full date.
Enter the above into excel sheet and apply the below formula to get the full date value.
Find the difference between two days in terms of Total Years, Total Month, and Days.
Assume you are working in an HR department in a company and you have employee joining date and relieving date data. You need to find the total tenure in the company. For example 4 Years, 5 Months, 12 Days.
Here we need to use DATEDIF function to get the result as per our wish. DATE function alone cannot do the job for us.
If we just deduct the relieving date with joining date we get the only number of days they worked, we get in detail.
In order to get the full result i.e Total Tenure, we need to use DATEDIF function.
DATEDIF function is an undocumented formula where there is no IntelliSense list for it. This can be useful to find the difference between year, month, and day.
The formula looks a lengthy one. However, I will break it down in detail.
Part 1: =DATEDIF (B2,C2,”Y”) this is the starting date and ending date and “Y” means we need to know the difference between years.
Part 2: &” Year” This part is just added into a previous part of the formula. For example, if the first part gives, 4 then the result will 4 Years.
Part 3: &DATEDIF(B2,C2,”YM”) Now we found the difference between years. In this part of the formula, we are finding the difference between the months. “YM” can give the difference between months.
Part 5: “&DATEDIF(B2,C2,”MD”) now we have a difference between Year and the Month. In this part, we are finding the difference between the days. “MD” can give us that difference.
Part 6: &” Days” this is added into the part 5. If the result from the part 5 is 25 then it will add Days to it. I.e. 25 Days.
Now I will explain you the different date formats in excel. There are many date formats in excel each show up the result differently.
Assume you are in a welfare team of the company and you need to send birthday emails to your employees if the there is any birthdays. Sending each one of them is a tedious task. So here, I have developed a code to auto, send birthday wishes.
Below is the list of employees and their birthdays.
I have already written a code to send the birthday emails to everyone if there is any birthday today.
Write the above in your VBA module and save the workbook as a macro-enabled workbook.
Once the above code is written on the VBA module save the workbook.
The only thing you need to do is add your data to the excel sheet and run the code every day you come to an office.
The given number should be >0 and <10000 otherwise excel will give the error as #NUM!
We can supply only numerical values. Anything other than numerical values, we will get eh error as #VALUE!
Excel stores date as serial numbers and show the display according to the format.
Guide to POWER Function in Excel? | https://www.educba.com/date-in-excel/ |
Igneous rocks are crystalline solids which are formed after the magma cools The sizes vary greatly depending on how quickly the magma cooled The slower the cooling, the larger the crystals in the final rock...
Where are igneous rocks, metamorphic rocks, and sedimentary rocks found in the world? And if you please can do this extra thing I will mark you as brainliest and it s just send a picture with the questions answer the paper will look like this a report on a guided lined paper...
All About Igneous Rocks Video for Kids This is the best video we found for kids to learn about the Igneous Rock Igneous Rocks Q A Question Are igneous rocks useful? Answer People use igneous rocks in many ways Granite counter tops are just one way Obsidian, which is a very sharp, glass-like volcanic rock was used for tools or arrowheads...
Igneous rocks can be found wherever volcanic activity has brought, or is bringing, magma, ash etc to the surface where they form basalt, tufa etc There are also igneous rocks that form underground, and have become exposed by erosion, eg granites, intrusive dyk...
This digital product is a digital version of insert map, Metamorphic Map of Nova Scotia, from the Nova Scotia Department of Natural Resources NSDNR Map ME 1979-1, Geological Map of the Province of Nova Scotia, compiled by J D Keppie and GK Muecke, 1979...
Rocks are generally separated into one of three different categories igneous, sedimentary, and metamorphic The word igneous means that the rock became a solid after having originally been hot magma, or lava These rocks are formed from the molten material found ,...
Igneous rocks are classified into two groups depending upon where the molten rock solidifies extrusive or intrusive Key Terms Felsic Derived from fel dspar si lica to describe an igneous rock having abundant light-colored minerals such as quartz, feldspars, or muscovite...
Igneous minerals form during the cooling and solidification of molten rock, or magma, produced at high temperatures around 650 to 1200 176 C beneath the Earth s surface Which minerals crystallize from the magma is influenced by factors such as its chemical composition, the temperature of crystallization, and the rate of cooling...
Igneous rock can be found on the surface in areas of current or past volcanism or in uplifted and eroded areas of past plutonic intrusions, deep underground nearly anywhere, or in areas of past or ....
Igneous rock is formed from cooled magma or lava The magma turns solid as it cools, and eventually becomes rock It is sometimes crystallized Igneous rock is formed from the cooling of magma or ....
Igneous Rocks Igneous rock is formed from magma that has cooled and become sol Molten rock is extraordinarily hot, sometimes exceeding 2,000 degrees Fahrenheit If this molten and partially crystallized material magma crystallizes underground before it reaches the surface, the rock is intrusive or plutonic ....
Igneous rocks are classified on the basis of texture and composition Texture is the overall size, shape and arrangement of mineral grains that make up the rock...
A few metals, such as gold, silver, and copper can be found in pure form as metal elements Nuggets or flakes of these metals can be taken straight from rock, but this is uncommon Metals are used to make many familiar things around us, such as copper in electrical wires, aluminum in soda cans, iron in saucepans, and solid gold in jewelry...
Igneous rock, any of various crystalline or glassy rocks formed by the cooling and solidification of molten earth materialIgneous rocks constitute one of the three principal classes of rocks, the others being metamorphic and sedimentary Igneous rocks are formed from the solidification of magma, which is a hot 600 to 1,300 176 C, or 1,100 to 2,400 176 F molten or partially molten rock material...
Where Igneous Rocks Are Found The deep sea floor the oceanic crust is made almost entirely of basaltic rocks, with peridotite underneath in the mantle Basalts are also erupted above the Earth s great subduction zones, either in volcanic island arcs or along the edges of continents...
Economic Significance of Igneous Rocks Since magma is the chief source of metal ores, many of them are associated with igneous rocks The minerals of great economic value found in igneous rocks are magnetic iron, nickel, copper, lead, zinc, chromite, manganese, gold, diamond and platinum...
A Igneous rocks are formed only from material ejected during a volcanic eruption B Igneous rocks are formed by the cooling of magma above Earth s surface and lava below the surface C Igneous rocks are formed by recrystallization due to intense heat and pressure...
Find this Pin and more on Nova Scotia Canada, Rocks and Minerals by Karolyn Collins Ijolite is a rare igneous rock consisting of nepheline and pyroxene Ijolite is a variety of foidolite feldspathoid-rich plutonic rock in which fledspathoids are dominating over feldspars...
Igneous Rocks Lesson 12 , Discordant and 2 Concordant A discordant igneous rock body cuts across the pre-exiting rock bed Batholiths and dikes are examples of discordant rock bodi A dike is a vertical or near vertical intrusive igneous rock body that cuts across rock beds , but it can also be found in an almost clear form Ancient ....
The following is a list of rock types recognized by petrologistsThere is no agreed number of specific types of rocks Any unique combination of chemical composition, mineralogy, grain size, texture, or other distinguishing characteristics can describe rock typ...
Sedimentary Rocks As rocks are exposed to the elements at the surface of the earth, those elements Wind, Water/ice, even air itself start breaking down the rock into smaller and smaller piec...
Gabbro is also found with other plutonic rocks in batholiths when bodies of rising magma are low in silica Igneous petrologists are careful about their terminology for gabbro and similar rocks, in which gabbroid, gabbroic and gabbro have distinct meanings...
Igneous Rocks 101 An Igneous rock is the product of cooled solidified magma/lava As magma/lava cools it goes through the process of crystallization which turns it into an igneous rock...
Igneous textures in thin section Texture categories Degree of crystallinity , plagioclase, and perthite Halifax, Nova Scotia, Canada Plane/cross-polarized light, field width is 6 mm , and alkali feldspar In some cases these are found in pegmatites and other felsic rocks, but the textures are also found in mafic rocks as the last bit ....
Igneous Appalachian rocks include pegmatite, alaskite, mica and feldspar formed from molten magma Rocks of dunite, and olivine containing peridotite are found in the southern rang Metamorphic Rocks...
GEOLOGYThe geologic history of Texas is recorded in rocks found in outcrops throughout the state and in rocks penetrated by boreholes drilled primarily in the search for oil and natural gas...
Basalt Basalt is one of the few igneous rocks found in Florida Igneous rocks are formed when magma or lava cools and solidifies into a hard rock Most of the time lava comes through volcano...
Types of Rocks Rocks are not all the same The three main types, or classes, of rock are sedimentary, metamorphic, and igneous and the differences among them have to do with how they are formed Sedimentary Sedimentary rocks are formed from particles of ,...
Mantle Plumes, Hotspots and Igneous rocks 1 Mantle Plumes, Hot Spots and Igneous Rocks , islands have a very similar composition to those found at MOR, except there are some , The type of igneous rock formed depends on a number of factors, including the...
Chapter 4 Igneous Rocks and Intrusive Activity STUDY PLAY What two types of parent rocks make up most of Earth s crust and mantle? , Where are extrusive igneous rocks found? 1 2 3 1 western portions of Americas, where they make up the volcanic peaks of the Cascade Range and the Andes Mountains 2 Many oceanic islands, including .... | https://www.petra4yourkids.nl/system/9669/where-are-scotia-igneous-rocks-found.html |
The Greek word for fire aptly describes the source of rocks that come from molten magma and lava. Environmental conditions above ground, near the surface, and deep below ground dictate how much time is required for heat to dissipate from this plasma-like, burning liquid. As the magma and lava cool, the molten liquid crystallizes and solidifies into different forms of igneous rock.
Magma originates from deep inside the Earth where extremely hot temperatures abound nearer to the center core. Continental tectonic plates move and shift; they can collide or separate from each other at points known as active plate boundaries. Heat is focused or injected into these points and solid rock melts into a plasma state of molten, liquid rock called magma. Then, the magma moves outward from the core, rising to the surface under pressure from surrounding cooler rock and flowing with the heat, melting even more rock in its path.
Some igneous rock forms inside the earth, or underground, while still more forms outside, or aboveground. All igneous rock starts deep in the earth as hot, molten magma. One manifestation of this is that basalt ( formed aboveground) and gabbro (formed underground) are two igneous rocks that are noted for their similar chemical makeup despite where they were formed.
Underground creations, or formations, of igneous rock are called “intrusive,” or “plutonic.” Aboveground formations are called “extrusive,” or “volcanic.”
Intrusive igneous rocks are doomed to complete their formation and cooling completely underground from magma. Such rocks take a long time to cool and form large crystals.
Extrusive igneous rocks form and cool completely aboveground from magma released aboveground through a volcano as lava. Such rocks cool rather quickly, leaving only enough time for very small crystals to form.
Once igneous rocks cool and form completely, they may not remain in the same place. The earth’s continental shelves are under continuous stresses and the release of energy will be manifested as motion. Surface weathering and erosion aids the change and movement of formed rocks. This means that igneous rock may not stay too long in one place, and may eventually change and journey back underground as part of the larger rock cycle process.
The family of intrusive igneous rock includes granite, granodiorite, diorite, gabbro, and tonalite.
The family of extrusive igneous rock includes rhyolite, scoria, pumice, basalt, obsidian, andesite, and dacite.
Andesite is observed in shades of gray and sometimes with red or green. It is fine-grained and may displays evidence of bubbling.
Basalt is the most common rock formed from lava. Its crystals are very small and not easily observed. Hawaii and the ocean floor are composed of basalt.
Dacite is light gray, but can be dark gray to black. It contains plagioclase, quartz, pyroxene, or hornblende. Dacite is one of the most common rock types associated with violent, energetic volcanic eruptions.
Granite is one of our most common rocks. It contains a mixture of quartz, feldspar and mica crystals. Granite crystals are large and easily observed.
Obsidian is formed by very rapid cooling of lava. Volcanic glass, or obsidian, is very hard and shiny. It can break or fracture into sharp edges. Early man used obsidian to construct crude knives and the points for arrows and spears.
Pumice is a very light and porous, and contains tiny crystals. Its texture is rough, with many holes and cavities. Pumice originates from lava containing high concentrations of gas bubbles. Pumice is so light that it can float in water.
Tonalite is coarse-grained and related to granite.
Igneous rocks are normally classified according to the minerals they contain. But, they may also be classified based upon their chemical compositions. | http://www.actforlibraries.org/igneous-rocks-in-earths-geology/ |
As you look out from this stop you will see the beaches of Awenda are littered with rocks of all different shapes, colours and sizes. The amazing thing about them is that almost all of them were transported here from the Canadian Shield by the Laurentide Ice Sheet and dropped 12,000 years ago with warming temperatures.
Some of the rocks you may find along Awenda’s beaches include igneous, metamorphic and sedimentary rocks.
Take the Igneous Challenge:
Igneous rocks form when molten magma solidifies and cools. This can occur deep underground, which is a slow process that allows large crystals to grow and form intrusive igneous rocks. Rapid cooling at the surface forms very fine crystals and extrusive igneous rocks.
Granite is a type of intrusive igneous rock which contains larger grain sizes. They are typically lighter in colour and lack an alignment of grains within the rock.
As you walk find an example of an igneous rock. How common are these volcanic beauties?
Next up:
Head to your left (if you are facing the water) down the beach to Stop #2. | https://www.awendapark.ca/discovery-challenge/bluff-formation/ |
Large crystals of mica sometimes weighing several hundred tons have been found in igneous rock in Canada Identify the environment of formation and the relative rate of cooling of the magma that...
Igneous rock classes and varieties with emphasis in those found in the Philippines origin and composition of magma Extrusive phenomena - lava and pyroclastics eruption types prediction and related phenomena Intrusive phenomena - dikes sills batholiths Philippine exampl Distribution of igneous rocks in the Philippin...
There are three basic rock types Igneous sedimentary and metamorphic Igneous Rocks Igneous rocks fiery rocks are made when molten material inside or outside the earth cools and becomes sol This melted rock is called magma when it is inside the earth When magma finds its way to the surface through cracks or volcanoes it is called...
The differences between extrusive igneous rocks and intrusive igneous rocks result primarily from their mode of formation Granite pumice and rhyolite come from magmas of very similar composition diorite and basalt come from magmas of very similar composition Igneous rocks were the first to appear during the earth-formation process...
an example of a mineral made up of a pure element an igneous rock commonly used as building material made up of quartz mica feldspar hornblende deposition process by which sediment settles out of the water or wind carrying it conglomerate...
Subvolcanic rocks are igneous rocks that are formed at medium depths and have a medium grain size Dolerite a subvolcanic rock with essential plagioclase pyroxene and opaque minerals The subvolcanic equivalent of basalt Porphyry a general term for igneous rocks that contain phenocrysts in a finer-grained groundmass...
Igneous rocks are produced this way but most igneous rocks are produced deep underground by the cooling and hardening of magma Magma is molten melted rock under the surface of the Earth It is produced in the upper reaches of the mantle or in the lowest areas of...
Igneous rock - Igneous rock - Convergent plate boundaries Igneous rocks associated with convergent plate boundaries have the greatest diversity In this case granite batholiths underlie the great composite volcanoes and consist of rocks ranging from basalt through andesite to dacite and rhyolite These boundaries are destructive and consume the subducting oceanic lithosphere formed at the...
Rock-forming mineral any mineral that shapes igneous sedimentary or metamorphic rocks and that acts as an intimate part of rock-making procedures typically or exclusively Those minerals on the other hand have a restricted mode of incidence or are created by more uncommon procedures such as metal ores vein minerals and cavity fillings...
As per Wikipedia Igneous rock derived from the Latin word ignis meaning fire is one of the three main rock types the others being sedimentary and metamorphicIgneous rock is formed through the cooling and solidification of magma or lava Igneous rock may form with or without crystallization either below the surface as intrusive plutonic rocks or on the surface as extrusive volcanic...
Examples of intrusive igneous rocks are diabase diorite gabbro granite pegmatite and peridotite Extrusive igneous rocks erupt onto the surface where they cool quickly to form small crystals Some cool so quickly that they form an amorphous glass These rocks include andesite basalt dacite obsidian pumice rhyolite scoria and tuff...
Oct 17 2019 0183 32 Igneous rocks are extremely sol Some metamorphic rocks slate phyllite can be broken into flat sheety plan Image A Does the rock look shiny A rock that contains a large amount of tiny mica grains muscovite or biotite could be metamorphic Be careful Large mica crystals are signs of igneous pegmatite rocksImage B...
Geological Importance of Igneous Rocks Igneous and metamorphic rocks make up around 90 to 95 of the top 16 km of the crust of the earth by volume Further igneous rocks form around 15 of the current land surface of the Earth Similarly most of the oceanic crust of our Earth is composed of igneous rock...
Metamorphic rocks arise from the transformation of existing rock types in a process called metamorphism which means change in form The original rock is subjected to heat temperatures greater than 150 to 200 176 C and pressure 100 megapascals 1 000 bar or more causing profound physical or chemical changeThe protolith may be a sedimentary igneous or existing metamorphic rock...
Metamorphic rocks forms due to heat and temperature which changes the original rock or parent rock into new rock The parent rocks are sedimentary igneous or metamorphic The metamorphic word comes from Greek and means to change form Metamorphic rocks are forms due to changes through a geological process like tectonic movements and magma intrusions What are Metamorphic Rocks...
Oct 10 2019 0183 32 Igneous rocks form when magma molten rock cools and crystallizes either at volcanoes on the surface of the Earth or while the melted rock is still inside the crust All magma develops underground in the lower crust or upper mantle because of the intense heat there Igneous rocks can have many different compositions depending on the magma they cool from...
Jun 15 2014 0183 32 An example of this is the landmark arc at Nakabuang Beach in Sabtang Island This white sand beach has a panoramic view that is accentuated by the famous arc rock...
Sep 27 2018 0183 32 Granitic rock below Hogback Mountain Eric Butler - NPS Photo The oldest rocks in Shenandoah National Park have survived the rise and fall of several mountain rang These are a complex set of igneous and metamorphic rocks whose minerals and textures preserve the story of their long and varied history...
igneous rocks examples mica Mica Define Mica At Dictionary Examples for mica Expand Heinz s group used mica a silicate mineral that can be cleaved to...
Jan 17 2020 0183 32 This page was last edited on 17 January 2020 at 16 09 Files are available under licenses specified on their description page All structured data from the file and property namespaces is available under the Creative Commons CC0 License all unstructured text is available under the Creative Commons Attribution-ShareAlike License additional terms may apply...
There are two basic types of Igneous Rocks- Extrusive Igneous Rocks Crystallize on the surface Intrusive Igneous Rocks Crystallize underneath the surface Examples of Extrusive Igneous Rocks Volcanic 1 Obsidian 2 Basalt 3 Andesite 4 Rhy...
are those formed by the cooling and hardening of molten rock mass The rocks are crystalline and contain quartz feldspar mica hornblende pyroxene and olivene Igneous rocks are not usually good sources of water although basalts are exceptions Small quantities of water are available in fractures and faults Examples are granite dioxite gabbro basalt and syenite...
Sedimentary and metamorphic rocks may be thought of as derivative rocks Igneous rocks are rocks formed from the crystallization of a liquid molten rock Igneous rocks may be divided into three - categori Intrusive or plutonic rocks crystallise from magma beneath the earth s surface...
This series can in a rather general way enable us to determine the origin of a given rock For example a rock that shows euhedral plagioclase crystals in contact with anhedral amphibole likely had an igneous protolith since a metamorphic rock with the same minerals would be expected to show euhedral amphibole in contact with anhedral...
The crystals in igneous rocks will be bigger if the rock cooled slowly and they will be smaller if the rock cooled quickly There are six minerals that can make up the igneous rock They are feldspar quartz pyroxene olivine amphibole and mica Examples of igneous rock include granite basalt and pumice Questions 1 Some people refer...
The sizes of grains are coarse and may be pegmatitic Texture is equigranular or porphyritic Sometimes diorites are foliated due to the roughly parallel arrangement of the minerals This igneous rock which measures 182 cm in length 1125 cm in width and 1035 cm in thickness Diorite consists essentially of the mineral plagioclase...
Jun 28 2019 0183 32 When magma or lava cools the magma and ore carried within it crystallize to form tiny minerals in the newly-created igneous rock Minerals found in such rock might include feldspar or mica Minerals can also be transported and released from water...
The following is an example of igneous rocks It is not an all inclusive list but a brief pictorial list of some common igneous rocks Igneous rocks get their name from the latin word for fire igneus The name is appropriate because these rocks are born of fire Beneath the thin rocky crust of the earth is...
Mar 22 2018 0183 32 In this article the different types of rocks that can be utilized in construction sites will be discussed Basalt Basalt is an igneous rock that is usually black It is one of the most abundant types of rock on Earth The most common uses of basalt include pavements roads and railroad ballasts where they are crushed into small fine piec...
Jan 17 2021 0183 32 Mica definition Mica is a hard mineral which is found as small flat crystals in rocks It has a great Meaning pronunciation translations and examples... | https://www.pimavell.pl/technology/7286/38ai5ryhbdaaf43.html |
A dark, shiny object caught my eye as it fell out of its hiding place, a small cavity in a fossil. The smooth, lightweight object was vastly different from the raggedly worn and delicate fossils in the donated box of Alaskan fossils I was helping sort through as part of my training at Mt. Blanco Fossil Museum. The interesting object I stumbled upon is a type of volcanic rock, called mahogany obsidian. Obsidian forms when hot lava is quenched by water and hardens into a glassy rock. It’s usually a semi-transparent black, but the mahogany obsidian I found is mostly opaque brown with darker black specks. People usually notice obsidian more than a lot of other rocks because it has a “concordal fracture” – meaning that it breaks in circular patterns. Because of this, the light-weight rock will often be found in a very smooth, rounded shape or with sharp, almost serrated edges.
Obsidian is classified as an “extrusive igneous” rock. You may remember last week in our “Clue of the Week” how we talked a little about “intrusive igneous” rocks, like granite, that are formed underground when magma cools and hardens (you can read about that here). Well, the main difference between “intrusive” and “extrusive” igneous rock is quite simply that “intrusive” rock is hardened magma inside the earth while “extrusive” rock is hardened lava that is exiting the underground and spilling out on the surface. The difference between magma and lava is that magma is underground and lava leaks out onto earth’s surface.
There are many other types of extrusive igneous rocks, like obsidian, some of which you might see every day. Do you ever use a pumice stone on your feet during a pedicure? It has lots of little holes and can even float on water. It may be helpful to think of pumice as lava foam because it forms when bubbly lava (lava mixed with dissolved gasses) hardens. It’s as if all the bubbles that the two-year-old filled the sink with hardened into a rock (just with hot lava instead of soapy water). You may also see a kind of lava rock, called scoria, in your yard. Scoria is similar to pumice, but a lot darker and usually with much larger holes. This is because the lava that scoria is made of has more metal (like iron) in its chemistry than the lava that pumice is made of.
Obsidian, pumice, and scoria are just a few common, but interesting examples of extrusive igneous rock – or simply put, lava rock. Rocks like these can be a sobering reminder of how, in spite of human efforts, God is ultimately in control of our planet. We can try to predict things like earthquakes and volcanic eruptions that these rocks (and many others) are formed by so that damage can be minimized, but the earth is the Lord’s. | http://creationclues.org/2015/02/06/lava-rocks/ |
feb 01, 2019 because igneous rocks contain a large number of strong paramagnetic substances, such as magnetite, hornblende, and biotite, the susceptibility is significantly higher than sedimentary rocks In general, from acid, middle to mafic igneous rocks, the susceptibility of igneous rocks gradually increases.igneous rock rocks formed when volcanic magma solidifies, for example, basalt. incoherent frequency that are out of step, nonresonant. karni japanese term for the spirit of an object, rock tree,etc. lava molten rock reaching the earths surface where it rapidly cools. fine grained.
types of igneous rock. igneous rocks are mainly classified as intrusive and extrusive: intrusive igneous rock: intrusive igneous rocks crystallize below the surface of the earth. because cooling occurs slowly for these crystals, the crystals grow larger. some common examples of these rocks include granite, pegmatite, and diorite.geologists like igneous textures because they reveal so much about how a rock formed. the first set of textures focuses on the size of mineral crystals. crystal size primarily reflects the rate of cooling, but is also often strongly affected by rock composition
oct 22, 2020 the word igneous is derived from the latin word ignis, meaning fire. this describes how magma, or rock that has been melted by fire, is the basis of all igneous rocks. much of the earths surface, and the rock found within the earths crust is composed of igneous rock.peridotite is a dark-colored igneous rock consisting mostly of olivine and pyroxene. It is an important rock type because the earths mantle is predominantly composed of it. classification diagram of ultramafic rocks. note that neither peridotite nor pyroxenite are single rock types. they are further divided into subtypes.
mar 01, 2012 volcanic ash is a fine mixture of minerals and rock fragments thrown out of a volcano during exposive volcanic eruption. here is an example of ash from the volcano that is responsible for the most deadly eruption in the history of usa. the volcano is of course mount st. helens and it the table below shows examples of common metamorphic rocks. clicking on the name of the rock will bring up a larger picture and a description of the rock type in a new window. remember these rocks are formed under extreme heat and pressure. learn more about metamorphic rocks here.
jan 01, 1972 chapter magnetic properties OF oceanic basalts diamagnetism and paramagnetism If a substance acquires an intensity of magnetization in a field of the volume magnetic susceptibility .jh, while the mass susceptibility jph where is the density.oct 21, 2017 igneous rocks are formed by cooling or solidification of molten or partly molten material, i.e. from a magma or lava. igneous rocks are first formed rocks which had made up the primodial earths crust. for this reason, they are called primary rocks. origin of igneous rocks the igneous rocks are formed at high temperature directly
igneous rocks that form when lava cools on earths surface. they contain small mineral grains or crystals because they cool quickly. examples of igneous rock. basalt, granite, obsidian, examples of sedimentary rock. coal, sandstone, conglomerate, gypsum, limestone. examples of metamorphic rock.An example of extrusive igneous rocks is basaltic rock and they can be located in the north eastern part of nigeria. In the deep interior of the earth due to cooling, magma may be crystallized to form intrusive rock. If the magma moves its way to the surface of
igneous rocks ore bodies environmental archeomag eoma magnetic minerals and magnetic anomalies magnetic anomalies are caused by lateral changes in the magnetic mineral content of rocks, and so re ect lateral changes in lithology. most minerals are not magnetic and so do not contribute to examples of igneous rocks granite gray or light red. composed of quartz, potassium feldspar and mica. porphyry dark red. composed of feldspar and quartz. gabbro thick texture. It consists of calcium plagioclase, pyroxene, olivine, hornblende and hypersthene.; sienite it is distinguished from granite because it does not contain quartz.
except for rare monomineralic rocks, rocks consist in general of all three kinds i.e. diamagnetic, paramagnetic and ferromagnetic minerals. In order to get an idea of the contribution of individualexamples of intrusive igneous rocks are: diabase, diorite, gabbro, granite, pegmatite, and peridotite. extrusive igneous rocks erupt onto the surface, where they cool quickly to form small crystals. some cool so quickly that they form an amorphous glass. these rocks include: andesite, basalt, dacite, obsidian, pumice, rhyolite, scoria, and tuff.
examples of aphanitic igneous rock include basalt, andesite and rhyolite. porphyritic texture porphyritic this type of texture develop when conditions during cooling of a magma change relatively quickly. porphyritic basically means the mix of groundmass classification of igneous rocks: the subject of classification of igneous rocks is perhaps one of the most thoroughly discussed problems of petrology and yet without any universally accepted solution. At the same time, a few methods, as mentioned below, have been variously used successfully for classifying these rocks for different purposes.
rocks september 14, 2011 We use your linkedin profile and activity data to personalize ads and to show you more relevant ads.porphyry is an igneous rock characterized by porphyritic texture. porphyritic texture is a very common texture in igneous rocks in which larger crystals are embedded in a fine-grained groundmass. porphyry is an igneous rock that contains larger crystals in a fine-grained groundmass. k-feldspar phenocrysts in this sample.
rock dusts are valued for the fineness of grind and afiape element content. some examples of rock dusts on the market include azomite, mckenzie rock flour, planters ii, and desert dyna-min. flora-stim is a clay-based rock dust material. rock dusts are part of a broad class of non-synthetic fertilizer materials used in organic farming. generically,the classicalapplication of the majority of minerals In the case of magnetite, the distribution anisotropy & alignment of ams is controlled bythe shape preferred orientation themagnetic domains
igneous rocks: advertisements: acid igneous rocks: these rocks are rich in free silica in the form of quartz granite is a typical example of this group of igneous rocks. granites are generally very hard and resistant rocks. they are effected only slightly under normal metamorphic conditions but when the degree of metamorphism is igneous rock igneous rock structural features: the structure of an igneous rock is normally taken to comprise the mutual relationships of mineral or mineral-glass aggregates that have contrasting textures, along with layering, fractures, and other larger-scale features that transect or bound such aggregates. structure often can be described only in relation to masses of rock larger than a
rocks are generally separated into one of three different categories: igneous, sedimentary, and metamorphic. the word igneous means that the rock became a solid after having originally been hot magma, or lava. these rocks are formed from the molten material found beneath the earths crust.the following is an example of igneous rocks. It is not an all inclusive list but a brief pictorial list of some common igneous rocks. igneous rocks get their name from the latin word for fire igneus. the name is appropriate because these rocks are born of fire. beneath the thin rocky crust of the earth is
jun 13, 2020 the moon that rotates the earth is also made of igneous rocks. pumice stone that is used for various purposes is perhaps the example of the lightest igneous rock on planet earth. these rocks are rich in certain types of minerals that help in plants to grow properly. let us look at some examples of igneous rocks.igneous rocks are formed when molten substances below the earth surface cools down and solidifies. these molten substances are called magma or lava. magma can be derived from melting of existing rocks on the earth crust. the solidification of molten magma into igneous rock may be below the earths surface or on the earths surface giving rise to the two types of
igneous rock granite: granite and other rocks of the granite family are the most widely distributed of the deeper plutonic igneous rocks forming the major component of the earths crust. It is a light coloured rock. the dominant mineral of the rock is alkali feldspar which occurs as large crystals. granite can occur in large rock examples of aphanitic igneous rock include basalt, andesite and rhyolite. glassy or vitreous textures occur during some volcanic eruptions when the lava is quenched so rapidly that crystallization cannot occur. the result is a natural amorphous glass with few or no crystals. examples
list three examples of igneous rocks. andesite, basalt, pumice. list three examples of sedimentary rocks. limestone, halite, gypsum. list three examples of metamorphic rocks. marble, gneiss, slate. describe and give an example of how it possible for two igneous rocks to have the same mineral composition but be different rocks. | https://www.kecoautoindustries.in/nigeria/2020_Apr_26319.html |
# Intrusive rock
Intrusive rock is formed when magma penetrates existing rock, crystallizes, and solidifies underground to form intrusions, such as batholiths, dikes, sills, laccoliths, and volcanic necks.
Intrusion is one of the two ways igneous rock can form. The other is extrusion, such as a volcanic eruption or similar event. An intrusion is any body of intrusive igneous rock, formed from magma that cools and solidifies within the crust of the planet. In contrast, an extrusion consists of extrusive rock, formed above the surface of the crust.
Some geologists use the term plutonic rock synonymously with intrusive rock, but other geologists subdivide intrusive rock, by crystal size, into coarse-grained plutonic rock (typically formed deeper in the Earth's crust in batholiths or stocks) and medium-grained subvolcanic or hypabyssal rock (typically formed higher in the crust in dikes and sills).
## Classification
Because the solid country rock into which magma intrudes is an excellent insulator, cooling of the magma is extremely slow, and intrusive igneous rock is coarse-grained (phaneritic). However, the rate of cooling is greatest for intrusions at relatively shallow depth, and the rock in such intrusions is often much less coarse-grained than intrusive rock formed at greater depth. Coarse-grained intrusive igneous rocks that form at depth within the earth are called abyssal or plutonic while those that form near the surface are called subvolcanic or hypabyssal.
Plutonic rocks are classified separately from extrusive igneous rocks, generally on the basis of their mineral content. The relative amounts of quartz, alkali feldspar, plagioclase, and feldspathoid are particularly important in classifying intrusive igneous rocks, and most plutonic rocks are classified by where they fall in the QAPF diagram. Dioritic and gabbroic rocks are further distinguished by whether the plagioclase they contain is sodium-rich, and sodium-poor gabbros are classified by their relative contents of various iron- or magnesium-rich minerals (mafic minerals) such as olivine, hornblende, clinopyroxene, and orthopyroxene, which are the most common mafic minerals in intrusive rock. Rare ultramafic rocks, which contain more than 90% mafic minerals, and carbonatite rocks, containing over 50% carbonate minerals, have their own special classifications.
Hypabyssal rocks resemble volcanic rocks more than they resemble plutonic rocks, being nearly as fine-grained, and are usually assigned volcanic rock names. However, dikes of basaltic composition often show grain sizes intermediate between plutonic and volcanic rock, and are classified as diabases or dolerites. Rare ultramafic hypabyssal rocks called lamprophyres have their own classification scheme.
## Characteristics
Intrusive rocks are characterized by large crystal sizes, and as the individual crystals are visible, the rock is called phaneritic. There are few indications of flow in intrusive rocks, since their texture and structure mostly develops in the final stages of crystallization, when flow has ended. Contained gases cannot escape through the overlying strata, and these gases sometimes form cavities, often lined with large, well-shaped crystals. These are particularly common in granites and their presence is described as miarolitic texture. Because their crystals are of roughly equal size, intrusive rocks are said to be equigranular.
Plutonic rocks are less likely than volcanic rocks to show a pronounced porphyritic texture, in which a first generation of large well-shaped crystals are embedded in a fine-grained ground-mass. The minerals of each have formed in a definite order, and each has had a period of crystallization that may be very distinct or may have coincided with or overlapped the period of formation of some of the other ingredients. Earlier crystals originated at a time when most of the rock was still liquid and are more or less perfect. Later crystals are less regular in shape because they were compelled to occupy the spaces left between the already-formed crystals. The former case is said to be idiomorphic (or automorphic); the latter is xenomorphic.
There are also many other characteristics that serve to distinguish plutonic from volcanic rock. For example, the alkali feldspar in plutonic rocks is typically orthoclase, while the higher-temperature polymorph, sanidine, is more common in volcanic rock. The same distinction holds for nepheline varieties. Leucite is common in lavas but very rare in plutonic rocks. Muscovite is confined to intrusions. These differences show the influence of the physical conditions under which crystallization takes place.
Hypabyssal rocks show structures intermediate between those of extrusive and plutonic rocks. They are very commonly porphyritic, vitreous, and sometimes even vesicular. In fact, many of them are petrologically indistinguishable from lavas of similar composition.
## Occurrences
Plutonic rocks form 7% of the Earth's current land surface. Intrusions vary widely, from mountain-range-sized batholiths to thin veinlike fracture fillings of aplite or pegmatite. | https://en.wikipedia.org/wiki/Intrusion_(geology) |
The notion of magma it comes from a word of the Greek language that can be translated as "pasta" . The term allows reference to the molten rock mass that is inside the planet land .
Magma is a mixture of solid, volatile and liquid materials . When it cools it crystallizes and consolidates, giving rise to igneous rocks . When crystallization occurs inside the land , is about intrusive or plutonic rocks ; instead, if magma rises to the surface, it becomes wash and only then it cools, generates effusive or volcanic rocks .
Another name by which igneous and volcanic rocks are known is magmatic rocks . It is important to highlight that both types are formed from magma and that the main difference between them is the medium in which they are formed. Volcanics, on the other hand, usually form after an eruption and the process It is much faster than those that arise beneath the surface.
Of the more than seven hundred igneous rock classes that have been documented, most were formed under the surface from the earth. Among the most common we can mention diorite, andesite, rhyolite, granite, basalt, gabbro and porphyry.
He magmatism It is the magma formation process. It is usually carried out at the edges of the tectonic plates, below the ocean ridges, although it can also be specified in areas located inside the plates and in the subduction areas.
When high temperatures are combined with high levels of Pressure , the rocks merge and become magma. That substance can only be found underground because, upon reaching the outside, it is called wash .
Magma usually concentrates in underground chambers (the so-called magma cameras ). There, the melt is maintained, which includes a liquid part, fragments of crystals and rocks and different dissolved gases. Magma chambers allow feeding volcanoes .
Many times volcanic eruptions occur when the vapor pressure of gases becomes greater than the pressure exerted by solid rocks that keep magma confined. This generates the appearance of multiple bubbles that try "escape" until the eruption and magma is expelled as lava.
In broad strokes, we can describe three types of magmas, which are granitic, andesitic and basaltic. The granitic magmas they have the least melting point of the three and can generate large plutons (plutons are masses of plutonic rocks that fit into the Earth's crust). Its origin takes place in orogenic areas such as the andesitic, although part of one of the other two magmas when they penetrate and melt sedimentary rocks or metamorphosed igneous whose composition is altered when the magma is incorporated.
The andesitic magmas , on the other hand, they have a percentage of silica less than sixty and a series of hydrated minerals, among which are several belonging to the groups biotite and amphiboles . These types of magma occur in any subduction zone, both in those of Cortex Oceanic as continental.
With respect to basaltic magmas , the most common of the three, we know that they can be of two types: alkaline, with a high level of potassium and sodium, generated in internal areas of the tectonic plates; tolerative, with a silica content of less than fifty percent and arising in the mid-ocean ridges (the elevations submarines found in the middle zone of the oceans). | https://na.erf-est.org/6186-magma.html |
Furthermore, the assumptions on which it is based and the conditions which must be satisfied are questionable, and in practice, no one trusts it beyond about 3,000 or 4,000 years, and then only if it can be checked by some historical means.The method assumes, among other things, that the earth's age exceeds the time it would take for C-14 production to be in equilibrium with C-14 decay.Extrusive igneous rocks are formed from magma that cools and solidifies at or near the Earth’s surface.Exposure to the relatively cool temperature of the atmosphere or water makes the erupted magma solidify very quickly.Intrusive igneous rocks are formed from magma that cools and solidifies deep beneath the Earth’s surface.
Minerals must be mined from the ground, either by surface, underground, or drilling methods.
A rock is an aggregate of one or more minerals; or a body of undifferentiated mineral matter. | http://vizozm.freeimagehost.ru/radioactive-decay-and-dating-rocks-27.html |
Below is a sample breakdown of the Igneous Rocks chapter into a 5-day school week. Based on the pace of your course, you may need to adapt the lesson plan to fit your needs.
|Day||Topics||Key Terms and Concepts Covered|
|Monday||Characteristics of magma||Magma composition and temperature, the geothermal gradient, melting zones and mantle plumes|
|Tuesday||Types of igneous rock||Plutonic rocks, plutons, batholiths, sills, dikes, volcanic rocks and lava|
|Wednesday||Bowen's reaction series||Continuous and discontinuous series, magmatic differentiation and stages of mineral formation|
|Thursday||Igneous rock classifications||Phaneritic and aphanitic rock textures, mafic and ultramafic rocks, felsic rocks and intermediate rocks|
|Friday||Locations of igneous rock||Diverging and converging tectonic plates, subduction zones|
1. Magma: Definition & Formation
Magma is molten rock found below the earth's surface. The temperature at which a rock melts is affected by its composition, pressure and water. Learn how magma forms and how it either feeds volcanoes or cools and crystallizes into igneous rock.
2. Volcanic vs Plutonic Igneous Rocks: Definition and Differences
Volcanic and plutonic rocks are types of igneous rock. Volcanic rocks form when lava cools and solidifies on Earth, and plutonic rocks form when magma cools and solidifies below Earth. Learn about different characteristics of these igneous rocks.
3. Bowen's Reaction Series: Crystallization Process & Magmatic Differentiation
Bowen's reaction series and magmatic differentiation are two ways of explaining how igneous rocks form. Learn about the continuous and discontinuous series of the Bowen's reaction series and how magmatic differentiation works in this video lesson.
4. Classification of Igneous Rocks: Textures and Composition
Igneous rocks can be classified by their texture and composition. Learn how texture is influenced by the cooling rate of magma and how different mineral compositions lead to different igneous rock classifications in this video lesson.
5. Locating Igneous Rocks: The Relationship Between Igneous Rocks & Tectonic Plates
Igneous rock can form where tectonic plates diverge or converge. Learn how the movement of tectonic plates can create the right conditions of the solidification of magma and the formation of igneous rocks.
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All rocks are ultimately derived from igneous rock. Do you agree with this statement? Discuss with specific reference to the rock cycle.
The Earth's crust is composed of different kinds of rocks, which are composed of minerals. Rocks are divided into three major groups, depending on their origin - igneous, sedimentary and metamorphic. All rocks are stages in a never-ending cycle, the rock cycle, which continuously refashions, redistributes and recycles existing crustal material.
The Earth's surface is subject to constant change. Some of this is driven by sub-surface processes such as, plate tectonics, folding, faulting and volcanic activities, which tend to raise the surface. However, some of the change is driven by surface processes such as weathering and erosion which tend to lower the surface. The rock cycle works non-stop building up and wearing down the Earth's surface materials.
The ultimate source of all rocks on the Earth's surface is magma.
Igneous rocks are formed when molten magma cools and solidifies, either underground or on the surface which results in having intrusive and extrusive igneous rocks. These rocks are constantly being destroyed and created. Once they are exposed at the surface they are weathered, mainly by the action of rain, frost and wind. There are various weathering processes which include salt weathering, frost weathering, insolation weathering, root-wedging and organic weathering amongst others. This is a very good example of denudation where weathering prepares material for transport, and mass wasting and erosion move that material downhill towards an ultimate base level, normally the sea. The movement of rock particles is done by active transporting agents such as running water, moving ice or blowing wind. If sedimentation continues, more material is buried till finally, the sediments are compressed and cemented together to form sedimentary rocks.
Other igneous rocks are transformed... | https://www.writework.com/essay/rocks |
Those that cool with the earth as the magma rises are called intrusive ig … neous rocks and they have course grain. Because of its resistance to chemical attacks, zircon will survive the contact metamorphism process which is trying to attack it with heat and pressure. Granite can be very fine-grained - it's called aplite - though it usually found in coarsely-crystalline forms pegmatite, if I recall correctly, for very coarse versions. Igneous rocks form directly by crystallization from materials from a magma melt. Magma is the heart of any igneous rock. Because it is a common rock and very hard, people used basalt for early choppers and for grinding stones to grind grains like millet and barley. Glassy rocks imply conditions of rapid chilling with no time for crystal nucleation and growth.
They typically contain very fine particles and are transported as suspended particles by turbulent flow in water or air, depositing once the flow settles. If such rock rises during the of solid mantle, it will cool slightly as it expands in an , but the cooling is only about 0. The State of New Hampshire has the nickname Granite State because of the amount of granite in the mountains of that beautiful state. Since the Stone Age, people have used obsidian to make cutting tools and tips for their arrows and spears. These rocks are characterized as either extrusive or intrusive. Igneous Rocks Igneous rock is formed from magma that has cooled and become solid. For example, at a depth of about 100 kilometers, peridotite begins to melt near 800 °C in the presence of excess water, but near or above about 1,500 °C in the absence of water.
Superheated volatile components are involved. They cool at a slower rate, forming large, coarsely-grained crystals. These massive tectonic plates are able to move and they basically float on top of the hot, deep layers of the earth. More typically, they are mixes of melt and crystals, and sometimes also of gas bubbles. Hence such rocks are smooth, crystalline and fine-grained.
When it breaks out onto the surface of the earth, we callit lava. High-temperature magma, most of which is basaltic in composition, behaves in a manner similar to thick oil and, as it cools,. Igneous rocks crystalize after the magma reaches the earth's surface. Hydrous magmas composed of basalt and andesite are produced directly and indirectly as results of dehydration during the subduction process. Igneous rock is formed through the cooling and solidification of magma or lava. Main article: Most only entirely melt for small parts of their histories. Some quartzite formations retain their original bedded layered structure such that when broken they form flagstones that are commonly used in landscaping or as veneer for buildings.
History of classification In 1902, a group of American petrographers proposed that all existing classifications of igneous rocks should be discarded and replaced by a quantitative classification based on chemical analysis. Intrusive rocks are also called plutonic rocks, named after , the Roman god of the underworld. Each category is then further subdivided. Magma solidifying under the surface results in coarser grained intrusive igneous rock. Classification Igneous rocks are classified according to mode of occurrence, texture, mineralogy, chemical composition, and the geometry of the igneous body. Chemical sedimentary rocks are formed from chemicals in the environment, such as gypsum found at White Sands National Park and halite, or rock salt. Abundances of trace elements are conventionally expressed as parts per million by weight e.
Igneousrocks that are relatively rich in elements that form feldspar andquartz. Since they're formed from primarily minerals, they're usually white, gray, or black rocks. What is Bowen's reaction series? The principle minerals that make up dacite are plagioclase, quartz, pyroxene, or hornblende. Recent dating of some of these rocks has revealed more precise and different ages. Each different type of rock is formed in a different way. Granite was widely used in ancient times. Those with higherfreezing points have more time to solidify and will produce largercrystals.
At greater depths, carbon dioxide can have more effect: at depths to about 200 km, the temperatures of initial melting of a carbonated peridotite composition were determined to be 450 °C to 600 °C lower than for the same composition with no carbon dioxide. The Great Pyramid of Giza contains within an enormous granite sarcophagus. Basalts are also frequently used in building and construction. Sedimentary rocks are formed from other rocks or substances that have been weathered, eroded or otherwise broken apart. The edges of this rock are very sharp.
Chemical classifications are preferred to classify volcanic rocks, with phenocryst species used as a prefix, e. The main difference between the two is the proportion of silica, with granite having the greater proportion. The prismatic crystals grow perpendicular to the walls of the vein. For example, where alava flow covers a tree. These crystals are so small that they can not be seen by the naked eye.
The map below shows the distribution of Proterozoic granitic intrusions in Colorado. As I mentioned wit h bi ochemical rocks, fossils can become rocks in time. Explosively erupted material is called and includes , and. Intermediate composition magma, such as , tends to form cinder cones of intermingled , and lava, and may have a viscosity similar to thick, cold or even rubber when erupted. The latter is important as the liquid mass surrounding the zircon will cause a new rim to be formed around the old zircon, just like the formation of tree rings. Metamorphic rocks were originally sedimentary rocks,and may well have one day contained fossils, but these rocks gotburied deeply over millions of years and have been affected byimmense heat and pressure as they were compressed by the rocksabove and edged themselves nearer the earth's molten magma below. What is the definition of an igneousrock? There are many different types of extrusive igneous rocks. | http://hirschelectronics.com/where-are-igneous-rocks-found.html |
Intrusive, or plutonic, igneous rocks form when magma cools slowly below the Earth's surface. Most intrusive rocks have large, well-formed crystals. Examples include granite, gabbro, diorite and dunite. | http://www.mineralogy4kids.org/rock-cycle/intrusive-igneous-rocks |
The rock masses that line the planet’s surface are formed by one or more minerals. Rocks are divided into three groups according to their origin: sedimentary, metamorphic and igneous.
Formation, Types and Texture
Igneous rocks constitute 90% of the earth’s crust and are formed by minerals that belong to the silicate group (this group is divided into ferromagnesian and non-ferromagnesian, which indicates that the rock contains iron or not). The word igneous is used in its description because this word means fire in Greek.
Igneous rocks are those that form after the magma cools down. Thus, magma from volcanic activity reaches the earth’s surface and finally solidifies. These rocks are subdivided into two different groups: plutonic and volcanic or extrusive. The former are formed from a slow cooling process of magma from the interior of the Earth’s crust (in this group, granite, diorite and peridotite stand out). Volcanics are formed from a rapid cooling process that occurs at the surface (among them are rhyolite, basalt and dacite).
When magma solidifies, large crystals are created. In this sense, the slower the cooling process, the greater the size of the igneous rock. If cooling is rapid, glass is formed instead of crystal.
Granite is the best known igneous rock
Granite was formed during the last 300 million years and is a direct consequence of the magma cooling process. This circumstance makes the granite present crystals of great size and that are observable with the naked eye. This rock can be found on the Earth’s surface due to erosion over the past 100 million years.
Large blocks are extracted from the mines, which are processed into smaller pieces. The crystals inside are evenly distributed.
Its final finish is carried out through a polishing process that removes the porosity of the original rock. This type of igneous rock has been and is highly valued as a building material, both for the interior and exterior of buildings. It is an elegant and attractive material and especially valued because it does not require special maintenance. | https://englopedia.com/what-is-igneous-rock/ |
Surf grass on the rocky reef -- appearing blurred in this time exposure -- is tossed back and forth by powerful ocean waves passing by above. San Clemente Island. Abstracts And Patterns Photo.
Clouds light up with blazing colors at sunset. Abstracts And Patterns Picture.
Gray whales at sunset, Laguna San Ignacio. Stock Photography of Abstracts And Patterns.
Beautiful underwater sunburst, glittering light through the ocean surface, Sea of Cortez, Baja California, Mexico. Photograph of Abstracts And Patterns.
The Mandelbrot Fractal. Fractals are complex geometric shapes that exhibit repeating patterns typified by self-similarity, or the tendency for the details of a shape to appear similar to the shape itself. Often these shapes resemble patterns occurring naturally in the physical world, such as spiraling leaves, seemingly random coastlines, erosion and liquid waves. Fractals are generated through surprisingly simple underlying mathematical expressions, producing subtle and surprising patterns. The basic iterative expression for the Mandelbrot set is z = z-squared + c, operating in the complex (real, imaginary) number set. Abstracts And Patterns Photos.
The Mandelbrot Fractal. Fractals are complex geometric shapes that exhibit repeating patterns typified by self-similarity, or the tendency for the details of a shape to appear similar to the shape itself. Often these shapes resemble patterns occurring naturally in the physical world, such as spiraling leaves, seemingly random coastlines, erosion and liquid waves. Fractals are generated through surprisingly simple underlying mathematical expressions, producing subtle and surprising patterns. The basic iterative expression for the Mandelbrot set is z = z-squared + c, operating in the complex (real, imaginary) number set. Abstracts And Patterns Image.
Detail within the Mandelbrot set fractal. This detail is found by zooming in on the overall Mandelbrot set image, finding edges and buds with interesting features. Fractals are complex geometric shapes that exhibit repeating patterns typified by self-similarity, or the tendency for the details of a shape to appear similar to the shape itself. Often these shapes resemble patterns occurring naturally in the physical world, such as spiraling leaves, seemingly random coastlines, erosion and liquid waves. Fractals are generated through surprisingly simple underlying mathematical expressions, producing subtle and surprising patterns. The basic iterative expression for the Mandelbrot set is z = z-squared + c, operating in the complex (real, imaginary) number set. Professional stock photos of Abstracts And Patterns.
Detail within the Mandelbrot set fractal. This detail is found by zooming in on the overall Mandelbrot set image, finding edges and buds with interesting features. Fractals are complex geometric shapes that exhibit repeating patterns typified by self-similarity, or the tendency for the details of a shape to appear similar to the shape itself. Often these shapes resemble patterns occurring naturally in the physical world, such as spiraling leaves, seemingly random coastlines, erosion and liquid waves. Fractals are generated through surprisingly simple underlying mathematical expressions, producing subtle and surprising patterns. The basic iterative expression for the Mandelbrot set is z = z-squared + c, operating in the complex (real, imaginary) number set. Pictures of Abstracts And Patterns.
Detail within the Mandelbrot set fractal. This detail is found by zooming in on the overall Mandelbrot set image, finding edges and buds with interesting features. Fractals are complex geometric shapes that exhibit repeating patterns typified by self-similarity, or the tendency for the details of a shape to appear similar to the shape itself. Often these shapes resemble patterns occurring naturally in the physical world, such as spiraling leaves, seemingly random coastlines, erosion and liquid waves. Fractals are generated through surprisingly simple underlying mathematical expressions, producing subtle and surprising patterns. The basic iterative expression for the Mandelbrot set is z = z-squared + c, operating in the complex (real, imaginary) number set. Abstracts And Patterns Photo.
Detail within the Mandelbrot set fractal. This detail is found by zooming in on the overall Mandelbrot set image, finding edges and buds with interesting features. Fractals are complex geometric shapes that exhibit repeating patterns typified by self-similarity, or the tendency for the details of a shape to appear similar to the shape itself. Often these shapes resemble patterns occurring naturally in the physical world, such as spiraling leaves, seemingly random coastlines, erosion and liquid waves. Fractals are generated through surprisingly simple underlying mathematical expressions, producing subtle and surprising patterns. The basic iterative expression for the Mandelbrot set is z = z-squared + c, operating in the complex (real, imaginary) number set. Abstracts And Patterns Picture.
Detail within the Mandelbrot set fractal. This detail is found by zooming in on the overall Mandelbrot set image, finding edges and buds with interesting features. Fractals are complex geometric shapes that exhibit repeating patterns typified by self-similarity, or the tendency for the details of a shape to appear similar to the shape itself. Often these shapes resemble patterns occurring naturally in the physical world, such as spiraling leaves, seemingly random coastlines, erosion and liquid waves. Fractals are generated through surprisingly simple underlying mathematical expressions, producing subtle and surprising patterns. The basic iterative expression for the Mandelbrot set is z = z-squared + c, operating in the complex (real, imaginary) number set. Stock Photography of Abstracts And Patterns.
The Mandelbrot Fractal. Fractals are complex geometric shapes that exhibit repeating patterns typified by self-similarity, or the tendency for the details of a shape to appear similar to the shape itself. Often these shapes resemble patterns occurring naturally in the physical world, such as spiraling leaves, seemingly random coastlines, erosion and liquid waves. Fractals are generated through surprisingly simple underlying mathematical expressions, producing subtle and surprising patterns. The basic iterative expression for the Mandelbrot set is z = z-squared + c, operating in the complex (real, imaginary) number set. Photograph of Abstracts And Patterns.
Fractal design. Fractals are complex geometric shapes that exhibit repeating patterns typified by self-similarity, or the tendency for the details of a shape to appear similar to the shape itself. Often these shapes resemble patterns occurring naturally in the physical world, such as spiraling leaves, seemingly random coastlines, erosion and liquid waves. Fractals are generated through surprisingly simple underlying mathematical expressions, producing subtle and surprising patterns. The basic iterative expression for the Mandelbrot set is z = z-squared + c, operating in the complex (real, imaginary) number set. Abstracts And Patterns Image.
The Mandelbrot Fractal. Fractals are complex geometric shapes that exhibit repeating patterns typified by self-similarity, or the tendency for the details of a shape to appear similar to the shape itself. Often these shapes resemble patterns occurring naturally in the physical world, such as spiraling leaves, seemingly random coastlines, erosion and liquid waves. Fractals are generated through surprisingly simple underlying mathematical expressions, producing subtle and surprising patterns. The basic iterative expression for the Mandelbrot set is z = z-squared + c, operating in the complex (real, imaginary) number set. Professional stock photos of Abstracts And Patterns.
The Mandelbrot Fractal. Fractals are complex geometric shapes that exhibit repeating patterns typified by self-similarity, or the tendency for the details of a shape to appear similar to the shape itself. Often these shapes resemble patterns occurring naturally in the physical world, such as spiraling leaves, seemingly random coastlines, erosion and liquid waves. Fractals are generated through surprisingly simple underlying mathematical expressions, producing subtle and surprising patterns. The basic iterative expression for the Mandelbrot set is z = z-squared + c, operating in the complex (real, imaginary) number set. Pictures of Abstracts And Patterns.
Clouds held back by island crest. Abstracts And Patterns Photo.
A garibaldi fish (orange), surf grass (green) and palm kelp (brown) on the rocky reef -- all appearing blurred in this time exposure -- are tossed back and forth by powerful ocean waves passing by above. San Clemente Island. Abstracts And Patterns Picture.
Beautiful underwater sunburst, glittering light through the ocean surface, Sea of Cortez, Baja California, Mexico. Stock Photography of Abstracts And Patterns.
North Pacific humpback whale, blow at sunset. Photograph of Abstracts And Patterns.
Sunrise light on clouds. Abstracts And Patterns Photos.
Beautiful underwater sunburst, glittering light through the ocean surface, Sea of Cortez, Baja California, Mexico. Abstracts And Patterns Image.
Beautiful underwater sunburst, glittering light through the ocean surface, Sea of Cortez, Baja California, Mexico. Professional stock photos of Abstracts And Patterns.
Land visit and sunset, skiff and tourists. Pictures of Abstracts And Patterns.
Point Loma lighthouse. Abstracts And Patterns Photo.
Cabrillo Monument lighthouse at sunset, Point Loma. Abstracts And Patterns Picture.
Sunset reflections in the Tuolumne River. Stock Photography of Abstracts And Patterns.
Surf grass on the rocky reef -- appearing blurred in this time exposure -- is tossed back and forth by powerful ocean waves passing by above. San Clemente Island. Photograph of Abstracts And Patterns.
Clouds form at dawn before a storm rolls in. Abstracts And Patterns Photos.
Clouds form at dawn before a storm rolls in. Abstracts And Patterns Image. | http://www.oceanlight.com/abstracts_and_patterns_photo.html |
By Abimbola O. Asojo, Ph.D, [email protected] of Design, Housing and Apparel,College of Design,University of Minnesota,240 McNeal Hall, 1985 Buford Avenue,ST Paul, MN 55108,USAUniversity of Minnesota
The notion that African cultures demonstrate principles of rational planning has often not been widely accepted. This paper discusses fractal geometry in Yoruba and Benin Nigerian spaces. Fractals are swirling patterns for modeling in biology, geology, and the natural sciences. The five components of fractal geometry are recursion, scaling, self-similarity, infinity, and fractional dimension. Fractals occur in a loop, the output for one step is the input for the next step. Fractals also consist of similar shapes in different scales.
Eglash in his book African Fractals: Modern Computing and Indigenous Design notes “while fractal geometry can indeed take us into the far reach of high science, its patterns are surprisingly common in traditional African designs, and some of its basic concepts are fundamental to African knowledge systems (p. 3). Eglash finds the self-similarity of fractals in what is characterized as “circles of circles of circular dwellings, rectangular walls enclosing smaller rectangles” were the basis of planning in many African ethnic groups.In Yoruba settlements, fractals are seen in rectangular walls enclosing rectangles with streets that branch down to tiny footpaths with striking geometric repetition.
Fractals are also seen in carvings, architecture, ornamentation, jewelry and women’s hairstyles. In Yoruba cities, houses are grouped in compounds according to lineage, occupation, and position in town. The center and the most important part of every Yoruba town is the afin, Oba's palace (King's palace). Yoruba traditional dwellings consist of four rectangular units facing a central courtyard, this style is commonly referred to as Impluvium style. The entrance facade is defined by a series of columns. Several rooms surround the central courtyard. A set of grandiose columns emphasizes the entrance facade. The courtyard is surrounded by a large verandah for congregation.In the Yoruba and Benin monarchial system, the Oba's (king's) palace was designed as a larger version of the impluvium style house. This configuration consisted of rectangular walls enclosing smaller rectangles.
The palaces also included elaborately carved columns that supported gable roofs along the courtyard perimeter. Yoruba palaces sometimes had as many as a hundred courtyards that were often larger than an ordinary house. The largest palace in the Yoruba Oyo Empire was larger than a football field. Each of its courtyards was reserved for special functions.
The largest was for public assemblies or dancing at festivals, the smaller ones for private activities of the king. The Impluvium style dwelling in traditional Nigerian architecture illustrates some aspect of fractal geometry, which is also more evident in the Yoruba and Benin palace architecture.
The palaces are larger scale versions of the dwellings and have been described as rectangular fractals, which possess self-similar patterns of different scales occurring recursively. The palace design illustrates various shapes, volumes, and planes assembled together to create the form of the palace.
These elements can be characterized as vocabularies of form from traditional Yoruba spaces. The shapes, volumes, and planes are organized around a courtyard and/or entrance axis in varying scales and fractional dimension. | https://ihuanedo.ning.com/group/healtheducation/forum/topics/fractal-geometry-in-indigenous-yoruba-and-benin-nigerian-architec |
From outer galaxies to our inner organs, nature’s fractal patterns—formed from chaotic equations repeating at different scales—are everywhere. Their “self-similarity” goes infinitely deep, as each pattern is made up of smaller copies of itself, ad infinitum. The mathematical beauty of fractals lies in the way that great complexity is driven by relative simplicity. Based on a list from Wired, click through to see the marvel of fractals all around you. | https://www.starsinsider.com/lifestyle/352757/phenomenal-natural-fractal-patterns-all-around-you |
Definition of fractal in English:
fractal
Mathematics
noun
A curve or geometric figure, each part of which has the same statistical character as the whole. Fractals are useful in modeling structures (such as eroded coastlines or snowflakes) in which similar patterns recur at progressively smaller scales, and in describing partly random or chaotic phenomena such as crystal growth, fluid turbulence, and galaxy formation.
Example sentences
- Many natural chaotic systems form fractals in the patterns that record the process.
- Mathematicians can use similar algorithms to generate fractals and other forms.
- The researchers discovered that Pollock's patterns could be characterized as fractals - shapes that repeat themselves on different scales within the same object.
adjective
Relating to or of the nature of a fractal or fractals: fractal geometry
More example sentences
- His research focuses on the interplay between fractal geometry and stochastic processes.
- Each level of expression contributed to the next, and over the course of millennia we created mathematical theory, from basic arithmetic to algebra, from calculus to fractal geometry.
- While classical geometry assumes that objects exist in integer dimensions, fractal geometry deals with objects that have non-integer dimensions.
Origin
1970s: from French, from Latin fract- 'broken', from the verb frangere.
For editors and proofreaders
Syllabification: frac·tal
Definition of fractal in:
What do you find interesting about this word or phrase?
Comments that don't adhere to our Community Guidelines may be moderated or removed. | http://www.oxforddictionaries.com/us/definition/american_english/fractal |
One of the mysteries of the English language finally explained.
nounMathematics
A curve or geometrical figure, each part of which has the same statistical character as the whole. They are useful in modelling structures (such as snowflakes) in which similar patterns recur at progressively smaller scales, and in describing partly random or chaotic phenomena such as crystal growth and galaxy formation.
- ‘Mathematicians have long been taken with the concept of fractals, which posits that patterns are made up of smaller, self-contained patterns.’
- ‘Euclidean geometry, Fibonacci numbers, the digits of pi, the notion of algorithms, concepts of infinity, fractals, and other ideas furnished the mathematical underpinnings.’
- ‘For example, we observe the presence of coexisting lipid phases (one phase less ordered than the other phase) and unstable domain growth that results in patterns such as fractals.’
- ‘Nature builds its fractals using statistical self-similarity: the patterns observed at different magnifications, although not identical, are described by the same statistics.’
- ‘The new sciences of complexity - fractals, nonlinear dynamics, the new cosmology, self-organizing systems - have brought about the change in perspective.’
- ‘He showed how fractals can occur in many different places in both mathematics and elsewhere in nature.’
- ‘Some of the complexity has been captured in modern pictures of fractals, many of which are created by iterating functions of this kind.’
- ‘Many natural chaotic systems form fractals in the patterns that record the process.’
- ‘The researchers discovered that Pollock's patterns could be characterized as fractals - shapes that repeat themselves on different scales within the same object.’
- ‘Computer programs help diagram elaborate formations of tiny spirals that form massive, spiraled fractals to describe, say, the economic tendencies of your new, island society.’
- ‘Importantly, such objects, known as fractals, turn out to be very useful for describing the shapes of physical objects such as mountains, coast lines, fractures, cracks and so on.’
- ‘Like a mountain range whose profile appears equally craggy when observed from both far and near, fractals are used to define curves and surfaces, independent of their scale.’
- ‘Mathematicians can use similar algorithms to generate fractals and other forms.’
- ‘Related, but not directly, I have spent much time getting to know fractals, 4d geometry, and other ‘strange’ mathematical phenomena.’
- ‘He likes problems in diverse fields (harmonic analysis, fractals, and tilings, to name a few) that involve algebraic integers, such as Pisot and Salem numbers.’
- ‘But as the technology and computing power advanced, those working on the project would test more and more complex patterns, such as the most obvious candidates - fractals.’
- ‘The approach of this paper was originally developed in to study the Hausdorff measure of certain parameterized families of fractals.’
- ‘The implications of map theory, game theory, topology, the fractals of chaos theory, have all lurked in ornament, awaiting their elevation to science.’
- ‘He argued that the combination of the personal computer, the Internet, and interest in fractals, chaos, and related mathematical topics has in recent years greatly facilitated the intertwining of art and math.’
- ‘Strange attractors have detailed structure on all scales of magnification and were one of the early fractals to be studied.’
adjectiveMathematics
Relating to or of the nature of a fractal or fractals.‘fractal geometry’
unmethodical, uncoordinated, undirected, disorganized, unarranged, unplanned, unpremeditated, indiscriminateView synonyms
- ‘This result also solved a long-standing open problem concerning the existence of certain fractal sets in the plane.’
- ‘His research focuses on the interplay between fractal geometry and stochastic processes.’
- ‘Each level of expression contributed to the next, and over the course of millennia we created mathematical theory, from basic arithmetic to algebra, from calculus to fractal geometry.’
- ‘During this time the writer also became increasingly curious about the link between science and spiritual potential, developing a keen interest in fractal geometry, quantum mechanics and chaos theory.’
- ‘Chaos theory is everywhere now: landscapes and starscapes in sci-fi movies, image compression software, even your laser printer uses fractal algorithms.’
- ‘His unique knowledge of subjects such as fractal dynamics, subspace theory, a tri-vector system and others, has made this energetic feedback system possible.’
- ‘More precisely, the recursive nature, which is essential for fractal models, is lacking in the procedural approach.’
- ‘Then we study the technique formally, and then apply it to images of fractal art.’
- ‘While classical geometry assumes that objects exist in integer dimensions, fractal geometry deals with objects that have non-integer dimensions.’
- ‘The current visual novelty of abstractions derived from digital technology, fractal geometry and literary theory is usually the product of inventive imagination rather than empathic imagination.’
- ‘It should be remembered that in his era there was little thought or knowledge of fractal geometry, curved space or different degrees of infinity.’
- ‘The first condition that must be fulfilled to apply scaling analysis techniques is that the growth behavior of a process lie in the fractal nature of the interface.’
- ‘To explain the concept of fractal dimension, it is necessary to understand what we mean by dimension in the first place.’
- ‘Would the present obsession with fractal geometry have come about anyway as part of the ever changing taste of architectural stylists, or is it an inevitable result of computer power?’
- ‘A number of fractal dimension algorithms were developed and evaluated using a field data set of 100 incidents.’
Origin
1970s: from French, from Latin fract- ‘broken’, from the verb frangere.
Pronunciation
Further reading
Top tips for CV writingRead more
In this article we explore how to impress employers with a spot-on CV. | https://en.oxforddictionaries.com/definition/fractal |
Fractal art from before computers were doing it.
Benoit Mandelbrot was a Polish-born mathematician. He received a doctorate from the University of Paris and emigrated to the U.S. in 1958. He is best known for his work with fractals, geometric patterns that are repeated at ever smaller scales to produce irregular shapes and surfaces that cannot be represented by classical geometry.
But before anybody knew Mandelbrot, artists were seeing fractals in nature and transfered the patterns in painting, design and sculpture…
Fractals may have become a cliche in modern computer graphics, but they have a long and rich history in art. | https://www.impactlab.com/2011/05/13/pre-fractal-art/ |
Fractal type were first considered by philsopher and matematician Gottfried Leibniz as he thought about the process of recursive self-similarity.
Fractals lend themselves to computer art, since they look infinitely complex, in a way that resembles many things in nature. The most notable objects that can reasonably be drawn algorithmically with fractals are: mist, smoke, clouds, terrain, plants and trees, lightning and snow flakes.
Some interesting recent movies have used fractals in their creation.
For more information, check out the work of Ronald Davis, George Grie, Matthias Groebel, Olga Kisseleva, John Lansdown, Manfred Mohr, Joseph Nechvatal, James Faure Walker and Perry Welman.
What Are Fractals Really
A fractal is an object that displays self-similarity at any level of detail or magnification. This is actually a somewhat obvious definition once you know how fractals are made. Essentially, fractals are made by contorting an object with a scaled down version of itself, and then repeating this process with every new contortion.
Fractals are known to have a similar level of detail regardless of the level of zoom, and strictly speaking, are too irregular to be described by simple geometric means.
In other words, fractals are simply a design made by repeatedly adding a scaled down copy of the base object to the object, and then repeating that process with that new piece.
This really is a case where an example should really help.
Fractals have several interesting properties. First each addition is similar to the base object. This is known as self-similarity in the fractal world.
Second, each addition is scaled by the same degree from it's parent. The degree of scaling is known as the fractal-dimension.
Third, fractals are made by repeating the process ad-infinitum.
Finally, fractals, essentially by definition since each addition is a scaled version of the base object, display self-similiarity at any level of magnification.
This process done by repeatedly taking a component of the fractal, adding a duplicated, usually smaller version of itself to the fractal, and repeating this process with the new element that was just created. The process is exemplified in nature by a tree splits whose trunk splits into smaller and smaller branches.
Benoît Mandelbrot
Benoît Mandelbrot (20 November 1924 – 14 October 2010) is arguably the kingpin of fractals, in part because he coined the term. Mandelbot was born in Poland, but moved to France in 1936 to avoid the war and eventually the United States in 1958 becoming an IBM fellow.
In the 1960's. Mandelbrot was working on a problem of measuring the coastline in Britain. If you have not thought of this problem before, you will realize it is a rather interesting problem since your result depends on the size of your measuring stick. If you use a mile long measuring stick, you will miss many in and out undulations that you would not miss with a foot long measuring stick, or a millimeter long stick. Mandelbrot simply classified all of situations where the length of the measuring stick would matter, or technically when the Hausdorff-Besicovitch dimension would be greater as a fractal. His fame was cemented when he shared images that displayed this property which caught peoples attention.
Self-Similarity
Two objects are said to be self-similiar in a fractal sense if they have the same shape. This is like kids who look like their parents who look like their grandparents, etc. Mathematicians actually break self-similarity into three different classifications.
How fractals are made in software
There are 4 main ways of generating fractals.
Four common techniques for generating fractals are:
Iterative, this is the main technique we discuss here. Orbit fractals in which a formula is applied at specific points repeatedly. Random fractals where a random process controls the process, and finally, Strange Attractors where complex differential equations exhibiting a chaotic nature are utilized.
The software that generates fractals is commonly recursive, meaning it will do the same thing over and over, with just slightly different parameters. For example, the software will, draw the trunk of a tree, then call itself again to draw the first big branch, then call itself to draw a small branch, etc until it has drawn the smallest element. After that, the software will first draw other twigs, then return to the smallest branch where it will again call and draw more twigs. This process of calling and returning will continue until it has finished drawing the last big branch, and is therefore done drawing the tree. | http://www.dgxi.com/Fractal-Art/ |
On Maximizing Understanding thru Fractals
The Fractal. It is an amazing representation of mathematical recursion, but it is not just a pretty face. It is the secret to being able to access you memory in functional ways, I think. It is the secret to understanding life in a holistic way. Anecdotally, it seems obvious to me and has for many years that we are all connected in a way that we cannot necessarily feel or experience directly. Recently my studies have introduced me to Terrance McKenna, and I am starting to think tht maybe it could be experienced directly without the methods I have studied. I have always discounted any elucidation that occurred when I was less than balanced, believing if G*d wanted to talk to me, She would not need me to be baked to do it.
Let me explain.
No, that would take too long. Let me sum up…
From the Wikipedia definition:
“In mathematics, a fractal is a subset of Euclidean space with a fractal dimension that strictly exceeds its topological dimension. Fractals appear the same at different scales, as illustrated in successive magnifications of the Mandelbrot set. Fractals often exhibit similar patterns at increasingly smaller scales, a property called self-similarity, also known as expanding symmetry or unfolding symmetry; if this replication is exactly the same at every scale, as in the Menger sponge, it is called affine self-similar. Fractal geometry lies within the mathematical branch of measure theory.”
Now, this idea that it is bigger than the topological space is so important to life. When you think about the fact your diaphragm only has to move about an inch to cover about a tennis court size of lung objects with new oxygen molecules. That is an amazing multiplicative event. And in the army, we called things like this force multipliers, but really they re transformers. And transformation is the key to Life, no matter what language you speak. You might not know that word for it, but you will understand why I say we are all on the same Path, it is just a different part of the Fractal. The Path is a Fractal, not a line, see? | https://www.opendiary.com/m/sisyphus/on-maximizing-understanding-thru-fractals-6081620/ |
The inspiration for her work is geometry, from the regular rhythmic patterns of architecture to the seemingly random fractals of nature. Working in AutoCAD she conceives patterns using the tools of Euclidean geometry, these being translation, rotation and reflection, with which she also incorporates the function of scaling – self-similarity at shifted scales – the fractal influence. Her drawing is released from two-dimensions by way of a saw through material, following the lines of the plan precisely. The sawn shapes are then strung, attaining three-dimensions through the tension of the steel cable that connects the layers. | https://bridgetkennedy.com.au/melissa-cameron/ |
intro’d to him too late in life.
then re-intro’d to him via Taleb.
perfect timing.
after having mentioned his name left and right throughout this book, i will finally introduce Mandelbrot, principally as the first person with an academic title with whom i ever spoke about randomness without feeling defrauded. other mathematicians of probability would throw at me theorems with russian names such as “sobolev,” “kolmogorov,” wiener measure, without which they were lost; they had a hard time getting to the heart of the subject or exiting their little box long enough to consider its empirical flaws. with Mandelbrot, it was different: it was as if we both originated from the same country, meeting after years of frustrating exile, and were finally able to speak in our mother tongue without straining.
Fractal is a word Mandelbrot coined to describe the geometry of the rough and broken—from the Latin fractus, the origin of fractured. Fractality is the repetition of geometric patterns at different scales, revealing smaller and smaller versions of themselves. Small parts resemble, to some degree, the whole. I will try to show in this chapter how the fractal applies to the brand of uncertainty that should bear Mandelbrot’s name: Mandelbrotian randomness.
The veins in leaves look like branches; branches look like trees; rocks look like small mountains. There is no qualitative change when an object changes size.
This character of self-affinity implies that one deceptively short and simple rule of iteration can be used, either by a computer or, more randomly, by Mother Nature, to build shapes of seemingly great complexity. This can come in handy for computer graphics, but, more important, it is how nature works. Mandelbrot designed the mathematical object now known as the Mandelbrot set, the most famous object in the history of mathematics. It became popular with followers of chaos theory because it generates pictures of ever increasing complexity by using a deceptively minuscule recursive rule; recursive means that something can be reapplied to itself infinitely. You can look at the set at smaller and smaller resolutions without ever reaching the limit; you will continue to see recognizable shapes. The shapes are never the same, yet they bear an affinity to one another, a strong family resemblance.
Fractals initially made Benoît M. a pariah in the mathematical establishment.
how fitting. pariah: outcast
So Mandelbrot spent time as an intellectual refugee at an IBM research center in upstate New York. It was a f*** you money situation, as IBM let him do whatever he felt like doing.
the luxury to do whatever you want. imagine 7 billion people with that (money absent) access/privilege. nclb redefined. 100% google for 100% people. 24/7.
The computer age helped him become one of the most influential mathematicians in history, in terms of the applications of his work, way before his acceptance by the ivory tower. We will see that, in addition to its universality, his work offers an unusual attribute: it is remarkably easy to understand.
Mandelbrot came to France from Warsaw in 1936, at the age of twelve. Owing to the vicissitudes of a clandestine life during Nazi-occupied France, he was spared some of the conventional Gallic education with its uninspiring algebraic drills, becoming largely self-taught.
..in the generation of visual intuitions lies a dialectic between the mathematician and the objects generated.
The rug at eye level corresponds to Mediocristan and the law of large numbers: I am seeing the sum of undulations, and these iron out. This is like Gaussian randomness: the reason my cup of coffee does not jump is that the sum of all of its moving particles becomes smooth. Likewise, you reach certainties by adding up small Gaussian uncertainties: this is the law of large numbers.
The key here is that the fractal has numerical or statistical measures that are (somewhat) preserved across scales—the ratio is the same, unlike the Gaussian.
Fractals should be the default, the approximation, the framework. They do not solve the Black Swan problem and do not turn all Black Swans into predictable events, but they significantly mitigate the Black Swan problem by making such large events conceivable. (It makes them gray.
Recall that nonlinear processes have greater degrees of freedom than linear ones.
perfect. no?
_________
feb – ted2010
Fractals and the art of roughness
_________
Benoît B. Mandelbrot (20 November 1924 – 14 October 2010) was a Polish-born, French and American mathematician, noted for developing a “theory of roughness” and “self-similarity” in nature and the field of fractal geometry to help prove it, which included coining the word “fractal”. He later discovered the Mandelbrot set of intricate, never-ending fractal shapes, named in his honor.
When he was a child, his family immigrated to France in 1936. After World War II ended in 1945, Mandelbrot studied mathematics, graduating from universities in Paris and the U.S., receiving a masters degree in aeronautics from Caltech. He spent most of his career in both the U.S. and France, having dualFrench and American citizenship. In 1958 he began working for IBM, where he stayed for 35 years and was an IBM Fellow.
________
Jim Al-Khalili‘s the secret life of chaos
________
________
article jun 2016 – Father Of Fractal Geometry Explains How He Discovered That Everything Is Connected
http://myscienceacademy.org/2016/06/19/father-of-fractal-geometry-explains-how-he-discovered-that-everything-is-connected/
video 2010
2 min – sometimes declaring a problem impossible is also a great advance
giving a word – fractal – gave the idea a certain reality
3 min – a formula can be very simple and create a universe of bottomless complexity.. | https://redefineschool.com/benoit-mandelbrot/ |
The Redbuds are the State tree of Oklahoma. In the past week or so, they have been really putting on a show.
State tree…
March 24, 2012
Driftwood burl…
February 25, 2012
More Beaver action…
February 16, 2012
Animals, trees beaver 2 Comments
I’m just amazed at the lumberjack skills of these creatures. I’d like to get a shot of one in the daytime, but they are quite shy. I think someone is coming to this site and cutting up the larger logs felled by the beavers and using it for firewood. Beavers seem to just use the smaller limbs for their homes.
Stumped…
January 23, 2012
Tiiimber…
January 21, 2012
Drip…
January 11, 2012
Tree fungus…
December 11, 2011
Fractals…
November 16, 2011
trees fractal, photography, tree branch Leave a comment
Fractals are geometric patterns that are repeated at ever smaller scales to produce irregular shapes and surfaces that cannot be represented by classical geometry. The branching of a tree is a pretty good example. The term was coined by Benoit Mandelbrot in 1975. He developed some special mathematic models to represent these patterns. Fractals can be seen in nature in things such as snowflakes and river systems or chemical compounds. They can be quite lovely when represented in art.
This post is for you Charlie! | https://phranksphotos365.com/category/trees/ |
Will Fractals Revolutionize Physics, Biology and Other Sciences?
A new discovery, reported in the latest Nature, hints at higher universal laws of the physical world, as well as new ways to approach and understand life in general. Even though the European discovery actually dealt with superconductors, it has an interesting twist with implications for the life sciences.
A group of physicists from London Centre for Nanotechnology at UCL and their collaborators at Sapienza University of Rome and European Synchrotron Radiation Facility in Grenoble, France were studying properties of so-called high-transition-temperature (high-Tc) copper oxide superconductors. They were looking at the microstructures that these superconductors form as they are cooled down. To the surprise of investigators, they discovered that microstructures, exhibited by oxygen atoms, seemed to organize into self-repeating fractals. Moreover, these fractal shapes, some extending almost to the millimeter scale, were correlating to superconductivity. In fact, larger fractals correlated with higher superconductivity temps.
What does it have to do with life? We think, plenty. Fractals, known for their geometric morphologies that are made up of patterns that repeat themselves at smaller scales infinitely, were first discovered by mathematician Benoit Mandelbrot in 1960s. Since then, they took the world of natural sciences by storm. As mathematicians and physicists discovered more and more interesting properties of these unique constructs, people started to notice fractals’ ubiquitous presence in nature. Whether in the living world or in inorganic one, they seem to pop up in unexpected places. Somehow, there are laws of physics that favor these structures for whatever reason.
To us, the discovery of fractal function is eerily reminiscent of polarization in pre-quantum mechanical physics. Not until Niels Bohr, Albert Einstein and others laid the foundations of quantum mechanics, polarization of light has remained a mystery. Now we have a new puzzle to answer. Fractals are ubiquitous in the physical and living world for some unknown reason, and there is a function to them.
Side image: Heat treatment improves the superconductivity of a ceramic copper oxide by creating a fractal network of connected channels of ordered oxygen defects. The green and red spheres represent the paired electrons responsible for superconductivity. Artwork by Manuel Vogtli (LCN). | https://www.medgadget.com/2010/08/will_fractals_revolutionize_physics_biology_and_other_sciences.html |
In the mid 70’s when people were playing around with early versions of computers, a mathematician was plotting the results of an equation containing a complex number, in a reiterative manner. And to his surprise, the results were quite fascinating: the patterns that emerged were beautiful to look at; but more interestingly, when you zoom into a small part of the pattern, it seemed to bring out a pattern that was so similar to the original. Similar, but different. And the mathematical discipline of fractals was born. It did not take long for people to recognize that this was an important discovery. Fractals had fractal dimensions. A river is not a straight line, mountains are not cones and clouds are not spherical. The new discipline brought out the fractal dimensions of natural structures. Mathematicians could paint trees, mountains, rivers and clouds with equations. And they looked more realistic than any painter could ever imagine. Scientists were suddenly seeing fractals everywhere. Terms such as scaling laws and power laws started appearing in almost all disciplines.
Soon mathematicians realized a hidden complexity: fractals that keep changing their dimensions in different directions. And the notion of multi-fractals was born. This too spread to other disciplines like wild fire. Patterns in time and space that hitherto seemed too complex to explain suddenly became simple enough. Even the complexity of literature, music, painting and other art forms came under the purview of this simplicity.
The study of science has always tried to model the present phenomena to predict the future. With different fields of the study of science evolving with the same goal, a modern branch of study has developed which finds its basics in the famous quote “The present determines the future, but the approximate present does not approximately determine the future”. Chaos Theory has recently turned fifty, celebrating more than half a century of flapping butterfly wings in Brazil and creating tornadoes in Texas. It was a meteorologist named Edward Lorenz who first outlined why seemingly consistent and knowable systems can still go wildly wrong.
Fractals are geometric shapes that are very complex and infinitely detailed. You can zoom in on a section and it will have just as much detail as the whole fractal. They are recursively defined and small sections of them are similar to large ones. One way to think of fractals for a function f(x) is to consider x, f(x), f(f(x)), f(f(f(x))), f(f(f(f(x)))), etc. Fractals are related to chaos because they are complex systems that have definite properties.
The word fractal was first introduced by Mandelbrot and Ness (1968) and laid the foundations for fractal geometry. He also advanced fractals by showing that fractals cannot be treated as whole-number dimensions; they must instead have fractional dimensions. Calculation of fractal dimensions or rather measuring self-similarity has been a major area in the field of study of chaos.
- Fractional Brownian Motions, Fractional Noises and Applications, SIAM Review 10(1968), no. 4, 422–437. , | http://www.dgfoundation.in/chaos-fractals-and-non-linear-studies/ |
A pattern is a form, template, or model (or, more abstractly, a set of rules) which can be used to make or to generate things or parts of a thing, especially if the things that are generated have enough in common for the underlying pattern to be inferred or discerned, in which case the things are said to exhibit the pattern. Pattern matching is the act of checking for the presence of the constituents of a pattern. The detection of underlying patterns is called pattern recognition. The question of how patterns arise naturally is dealt with by the scientific field of pattern formation.
Some patterns (for example, many visual patterns) may be directly observable through the senses.
Some patterns are named. Simple decorative examples are stripes and zigzags. Further examples include the regular tiling of a plane, echoes, and balanced binary branching.
The simplest patterns are based on repetition/periodicity: several copies of a single template are combined without modification. For example, in aviation, a "holding pattern" is a flight path which can be repeated until the aircraft has been granted clearance for landing.
Pattern recognition is more complex when templates are used to generate variants. For example, in English, sentences often follow the "N-VP" (noun - verb phrase) pattern, but some knowledge of the English language is required to detect the pattern. Pattern recognition is studied in many fields, including psychology, ethology, and computer Science.
In addition to static patterns, there may be patterns of movement such as oscillation.
Contents
Nature
The planets of our solar system are caught in an incredibly ancient pattern by the gravity of the Sun. The planets have been following their (very predictable) elliptical orbits for billions and billions of years. There is certainly a recognizable pattern/cycle there.
- Sea shells, Sand Dollars
- Sand dunes, Grand Canyon
- Tree branches, ferns, coastal lines, clouds
- Fir waves and tiger bush are examples of patterned vegetation
- Snowflakes
Golden Ratio
A reoccurring theme found in the biology of nature is the golden ratio. The golden ratio is a+b to a is as a is to b. It has a direct relationship to the Fibonnacci numbers. This pattern was exploited by Leonardo da Vinci in his art. The Fibonacci pattern has a closed-form expression. These patterns can be seen in nature, from the spirals of flowers to the symmetry of the human body (as expressed in Da Vinci's Vitruvian Man, one of the most referenced and reproduced works of art today.
Art
- Modern art: Mondrian, Op Art
- Impressionism: Pointillism
- Performance Art: Crop circles
- Music: Minimalism
Science and mathematics
Fractals are mathematical patterns. Naturally occurring patterns obey certain principles also found in fractals, for example self-similarity. Even though self-similarity in nature is only approximate and stochastic, integral measures describing fractal properties can also be applied to natural "fractals" like coastal lines, tree shapes, etc. (see fractal geometry). While the outer appearance of self-similar patterns can be quite complex, the rules needed to describe or produce their formation can be extremely simple (e.g. Lindenmayer systems for the description of tree shapes).
Patterns are also common in other areas of mathematics. Recurring decimals will repeat a sequence of digits an infinite number of times. For example, 1 divided by 81 will result in the answer 0.012345679... the numbers 0-9 (except 8) will repeat forever — 1/81 is a recurring decimal.
A reoccurring pattern is on of the 5 cornerstones of the definition of a mineral in geology. A mineral must show it's elements in a three-dimensional reoccurring pattern (aka a crystal matrix).
Computer Science
- Pattern matching
- Design patterns
- Regular expressions
Patterns in Pedagogics
Quotation
- "A pattern has an integrity independent of the medium by virtue of which you have received the information that it exists. Each of the chemical elements is a pattern integrity. Each individual is a pattern integrity. The pattern integrity of the human individual is evolutionary and not static."
R. Buckminster Fuller (1895-1983), U.S.American philosopher and inventor. Critical Path, 1981.
- "Art is the imposing of a pattern on experience, and our aesthetic enjoyment is recognition of the pattern."
Alfred North Whitehead (1861-1947), English philosopher and mathematician. Dialogues, June 10, 1943.
Mathematics is commonly described as the "Science of Pattern." | https://psychology.fandom.com/wiki/Pattern |
Since the early eighties the mathematical ideas of chaos theory and and the closely related field of fractals have captured the popular imagination. Chaos theory has found some application in fluid dynamics and related fields while fractals have proved popular as a method of creating digital imagery. Images created in this way may resemble natural objects such as clouds and coastlines. Intriguing patterns which are purely abstract in appearance may be generated which have a fascinating elegance and mystery. The best known of these is the Mandelbrot Set.
The essential feature of a fractal object is that of self-similarity or scalability, that is, that fractals are by definition similar on every scale however large or small. There is no way in which a person examining a fractal can tell whether they are looking at something very large or very small or somewhere in between; the fractal has the same "look" on every scale. This idea of similarity precedes the discovery of fractals. It was, for example, used in the analysis of surface gravity waves on liquids by the Russian mathematician Sergei Kitaigorodoskii as early as 1961. By assuming that ocean waves must be similar on every scale he was able to draw some interesting conclusions about the physics of ocean waves, in particular, about their power spectra.
Over the last 40 years or so a mystique has grown up around scalability and fractals. These are very elegant and seductive concepts but are they in fact valid descriptions of nature and natural objects? A moment's reflection will show that they are not. Far from being commonly fractal, natural objects are in fact never fractal. They may on occasion be fractal-like or self-similar over a range of scales but they must be self-similar on every scale in order to be truly fractal. Only mathematical objects can have this property. We know by experience that there is always some scale at which the self-similarity of natural objects breaks down. The "coastline" of a rocky headland in (perfectly still) water may be fractal-like over a range of scales from millimetres to tens of meters but on a spatial scale of hundreds of meters beaches become evident and these are not self-similar (there are no micro-beaches). Below the scale of millimetres the crystalline structure of the rocks themselves gives them a very different appearance from the same rocks on a larger scale.
The same is true of waves. Small waves do not look the same as large waves much to the chagrin of movie makers who wish to use wave tanks to film scenes of stormy seas. There is a lower limit to the size of gravity waves. At scales of centimetres and less, capillary waves are the dominant wave form on the surface of water because surface tension is more important than gravity at these scales. There are no gravity waves shorter than a few centimetres in wavelength and only gravity waves are seen to "break". Even when small gravity waves do break, their appearance is very different from large breaking waves because of the way that surface tension and viscosity control the bubble size in the foam.
All this may appear to be academic but it has had serious practical consequences. Because of Kitaigoroskii's profound but inaccurate insights into the nature of ocean waves, an entire generation of ocean wave specialists (who were nearly all mathematicians) believed that ocean wave "wind sea" power spectra must follow a fifth power law. They believed this despite considerable experimental evidence to the contrary. These idealized spectra were then used by engineers to compute design stresses on offshore structures. Because they used the fifth power law spectrum of theory rather than the fourth power law spectrum actually observed, these stresses were overestimated for big (long) waves and underestimated for small (short) waves. The nett result has been that all offshore structures are overdesigned. Oil rigs are very expensive things to build, so that this simple misconception may have cost the offshore oil industry hundreds of millions of dollars during the decades that the assumption of perfect scalability has been the "correct" view of ocean surface waves.
Another idea foisted on us by the mathematical idealogues is that images of fractals are somehow more pleasing to the eye than are non-fractals. No evidence is ever presented for this view which is after all, a testable hypothesis. Artists and graphic designers could be asked to assess the aesthetics of various patterns in double blind tests. The image at the top of this page shows part of the Mandlebrot set. The image below is a photograph of sunlight defracted by waves in shallow water. The upper image is a fractal. The lower image is not fractal because it is the outcome of both gravity waves and capillary waves at a scale at which they are both of roughly equal importance. The lower image is pleasant to look at nontheless whereas fractals tend to have a spooky, alien quality that is not always pleasing to the human eye. | http://www.scienceheresy.com/scienceheresyarchive/2010_09/scalability/index.html |
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Related to fractal: Fractal dimension
frac·tal(frăk′təl)
n.
An object whose parts, at infinitely many levels of magnification, appear geometrically similar to the whole. Fractals are used in the design of compact antennas and for computer modeling of natural-looking structures like clouds and trees.
[French, from Latin frāctus, past participle of frangere, to break; see fraction.]
frac′tal adj.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
fractal(ˈfræktəl) maths
n
(Mathematics) a figure or surface generated by successive subdivisions of a simpler polygon or polyhedron, according to some iterative process
adj
(Mathematics) of, relating to, or involving such a process: fractal geometry; fractal curve.
[C20: from Latin frāctus past participle of frangere to break]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
frac•tal(ˈfræk tl)
n.
a geometrical structure that has a regular or an uneven shape repeated over all scales of measurement and that has a dimension (frac′tal dimen`sion), determined according to definite rules, that is greater than the spatial dimension of the structure.
[< French fractale < Latin frāct(us) broken, uneven; term introduced by French mathematician Benoit Mandelbrot (born 1924) in 1975]
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
frac·tal(frăk′təl)
A geometric pattern repeated at ever smaller scales to produce irregular shapes and surfaces that cannot be represented by standard geometry. Even the most minute details of a fractal's pattern repeat elements of the overall geometric pattern. Fractals are widely used in computer modeling of irregular patterns and structures in nature, such as the patterns of seasonal weather. They are also considered to be a visual representation of chaos. See more at chaos.
The American Heritage® Student Science Dictionary, Second Edition. Copyright © 2014 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
ThesaurusAntonymsRelated WordsSynonymsLegend:
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|Noun||1.||fractal - (mathematics) a geometric pattern that is repeated at every scale and so cannot be represented by classical geometry|
pattern, form, shape - a perceptual structure; "the composition presents problems for students of musical form"; "a visual pattern must include not only objects but the spaces between them"
math, mathematics, maths - a science (or group of related sciences) dealing with the logic of quantity and shape and arrangement
Based on WordNet 3.0, Farlex clipart collection. © 2003-2012 Princeton University, Farlex Inc. | https://www.thefreedictionary.com/fractal |
This quotation by Mandelbrot shows that the Euclidean geometry - the perfect “clinical” shapes of cones, pyramids, cubes and spheres - is not the best way to describe natural objects. Clouds, mountains, coastlines and bark are all in contrast to Euclidean figures not smooth but rugged and they offer the same irregularity in smaller scales, which are some important characteristics of fractals - see chapter “ 2.2 Characteristics”. As the following pages indicate, fractal geometry, in opposition to Euclidean geometry, offers better methods for description or for producing similar natural-like objects respectively. The language in which it is expressed is called “algorithms”, by which complex objects like a fern or a cloud can be reduced to simpler formulas or transformation rules respectively. Fractals can be found everywhere from coastlines, border-lines and other natural rough lines to clouds, mountains, trees, plants, ... and maybe also in architecture. The following chapters explain what a fractal is in general and how fractals can be used for architectural analysis and in the stage of planning. Fractals are used as a helping tool for explanation in many fields ranging from medicine to economy. From this point of view fractals should not be excluded from architecture.
The computer-scientist Benoit Mandelbrot introduced the word "fractal" in the year 1975 to describe irregular, not smooth, curves. Fractal geometry in general has become more and more popular since Benoit Mandelbrot’s book “The Fractal Geometry of Nature ” was published for the first time in 1977 and the “Mandelbrot set” was defined in the year 1980. Since that time many of those computer-pictures and "monster curves", as Benoit Mandelbrot called curves with unusual characteristics such as the Koch curve, have been published - some of them will be introduced in chapter “3 Different Fractals”. They were mostly created with a mathematical background, but they can also be found in art because of their beautiful interesting appearance . In the eighties of the 20th century the “Mandelbrot set” could be found in many scientific journals last but not least because of its beauty - this kind of visualizing was, however, only made possible by the quick development of the computer. Subsequently today it is no problem for any of us to produce classical and natural looking fractals quickly and easily on the computer at home. Of course it is dangerous to think that we know enough about fractal geometry and the mathematical background so that we can start to use this "new" geometry in every field of our life. But, are we not now - with all the background of our society - in a position where we can deal with all the questions arising from the use of these new scientific theories and is this not more important than putting all the priority on finding the final result at the moment. To use new theories first means to define how they can help in a specific field and then to find applications in the next step. These days we can already look into other possible fields of application of fractal geometry: natural science, medicine, market analysis, manufacturing, ecology - and architecture? In any case architects and city-planners already use concepts and phrases for analysis which come from other fields, such as the biological metaphor: the city as an organism with the “heart" for the central business district, the “lung" for the green space, the “arteries and veins” for the hierarchy of communications routes - in this connection fractal geometry might provide a new vocabulary which explains the complexity of a city in a better way.
We can describe mountains, clouds, trees and flowers by models consisting of simpler geometric forms based on Euclidean geometry, for example using net models in CAD, but are they exactly what nature is ? The first two chapters below give an introduction to fractals and fractal geometry in a more general way, listing characteristics and explaining some examples. Then one chapter follows about the differences between Euclidean and fractal geometry and their expressions in the Euclidean and fractal dimension, introducing and explaining some measuring-methods of the fractal dimension.
Until a short time ago scientists described nature through so called “smooth” continuous mathematics, which is the mathematics of smooth forms such as lines, curves and planes and which is expressed in the language of Euclidean geometry. The “new” science of complexity does not try to simulate any more the rugged character of nature through smooth forms but it deals with the raggedness of the structure itself - this field of mathematics is expressed in the language of fractal geometry: “The whole is more than its parts”. The fractal new geometric art shows surprising kinship to Grand Master paintings or Beaux Arts architecture. An obvious reason is that classical visual arts, like fractals, involve very many scales of length and favor self-similarity . Chapter “5 Fractals and Architecture” to chapter “6 Fine Arts and City Planning” deal with the question if fractal geometry can be used in architecture and for the analysis of cities or at least with the question in which ways further research can be done - it lists the possible applications of fractal-theory in fine-art, city-planning and architecture, with regard to analytical, formal and practical aspects.
Fractal geometry may help us to understand and analyze complexity that can be found in towns of the Middle Ages but also in cathedrals and other man-made objects up to these days. It may also help us to transfer this complexity, which also arises from the development over time, to newly planned cities and buildings - cities and buildings may then also be reduced to simpler algorithms: the automatic architect ? Among other themes one part of chapter “5 Fractals and Architecture” deals with the so called “organic” architecture. In this context, natural structures, explained through fractal geometry, could serve as easy-to-use models for a new “organic”, natural-like architecture. The underlying structure, the character of a building will then follow the principles of fractal geometry that can be found in natural elements. This results in a connection between architecture and nature not only in a formal respect - e.g. with Antoni Gaudí - but also in the complexity of forms and in its character of self-similarity, irregularity and roughness - e.g. with Bruce Goff. Another section of this chapter deals with the question of the quality of buildings, which means asking why one building is regarded as "good" architecture while the other is regarded as "bad" architecture. It is clear that everyone has his or her personal access to architecture and evaluates buildings in a different manner. But there are buildings, which are more interesting in general than others, or there are buildings, which are more noticeable to most people than others - e.g. the acceptance of Gothic, which is related to fractal geometry, in contrast to the resentment towards modern buildings, which are related to Euclidean geometry. Subsequently the idea arises that maybe it is complexity that modern buildings lack. Chapter “7 Problems with Measuring” deals with measuring problems arising from the use of different computer-programs for calculating the box-counting dimension introduced in chapter “4 Dimensions”. Finally, this box-counting dimension is used in chapter “9 Statistics” to get a classification of elevations and ground plans of buildings and cities. In this context the fractal dimension is applied as an indication for roughness.
Comparison of natural objects with Euclidean geometry by the mathematician Benoit Mandelbrot in “The Fractal Geometry of Nature”. Bovill Carl, Fractal Geometry in Architecture and Design (1996), Birkhäuser Bosten, ISBN 3-7643-3795-8, p.4, Mandelbrot Benoit B., Dr. Zähle Ulrich (editor of the german edition), Die fraktale Geometrie der Natur (1991) einmalige Sonderausgabe, Birkhäuser Verlag Berlin, ISBN 3-7643-2646-8, p.13.
Warning of Michael Barnsley in the introduction to his book “Fractals Everywhere” (1988), Academic Press.
Bovill Carl, Fractal Geometry in Architecture and Design (1996), Birkhäuser Bosten, ISBN 3-7643-3795-8, p.3.
The Latin adjective "fractus" - from which the term “fractals” is derived - was used by Benoit Mandelbrot to denote a phenomenon with a new word. The Latin verb 'frangere' means “break into irregular fragments”, Mandelbrot Benoit B., Dr. Zähle Ulrich (editor of the german edition), Die fraktale Geometrie der Natur (1991) einmalige Sonderausgabe, Birkhäuser Verlag Berlin, ISBN 3-7643-2646-8, p.27.
Maybe it is this beautiful interesting appearance that brings a better access to mathematics: the theory of fractals and chaos is not only an abstract theory but it can also be visualised - mostly through the computer - which surely is helpful for better understanding of the underlying mathematics.
Batty and Longley, Fractal Cities (1994), Academic Press Inc., ISBN 0-12-4555-70-5, p.31.
That is what architects may be interested in: forms - their mathematical explanation and their application to architecture. Today we use the mathematical explanation of complex geometries, fractals, in animated cartoons and scienc fiction movies to generate trees, ferns, mountains, unknown worlds and whatever is found in nature. The fractal geometry reduces the complex forms to much simpler mathematical expressions which make computer files smaller and, reduced to a few iterations, above all quicker to compute - which means to produce. So one field of application may be in CAD where complex forms of nature such as clouds and trees may be constructed without using strange complicated wire models or 2-dimensional pictures.
Complexity in architecture means that elements of e.g. a facade - columns, capitals, base, architraves etc - can be grouped in a way that there is more than one equivalent interpretation presented to the observer. This is true for Michelangelos’ facade for the funerary chapel of San Lorenzo in Florence (1516-1534). Complexity does not mean complicated forms but the interconnection of elements that produce the whole. Von Meiss Pierre, Elements of architecture, from form to place (reprinted 1998), E & FN Spon, ISBN 0 419 15940 1, p.45.
Comparison by Benoit Mandelbrot in “The Fractal Geometry of Nature” - Die fraktale Geometrie der Natur (1991) einmalige Sonderausgabe, Birkhäuser Verlag Berlin, ISBN 3-7643-2646-8, p.35.
Bovill Carl, Fractal Geometry in Architecture and Design (1996), Birkhäuser Bosten, ISBN 3-7643-3795-8, p.115.
Of course this will not lead to an automatic architect: we know the limits of artificial intelligence. There exists, for example, a computer program which produces ground plans of villas by Palladio through algorithms. The grammar of buildings by Palladio was analyzed and brought into rules - for example the repeating symmetric axes and the continuous main-room. With the set of rules and the repeating recursive application of them, a defined grid and additional rules for the porticos, windows and doors under the control of Palladios rules of forms, the computer works out a couple of results that look like the villas built by Palladio - the underlying structure, the character is reproduced well. But there are some limits shown, for example in the third dimension, where too many rules for computing would be needed. Beside that the machine has a lack of knowing the meaning of functions - the relation to the neighborhood is missing. The program is neither able to sort out “wrong” ground floors which are not fitting that well, nor is there a limit in using the program for more complex forms.
The form of the roof of the Casa Batlló by Antoni Gaudí looks like the back of a dinosaur, the columns of the ground floor seem to be the feet of elephants and the balconies look like faces of animals. Jürgens Tietz: Geschichte der Architektur des 20. Jahrhunderts (1998), Könemann, ISBN 3-8290-0512-1, p12. | http://www.fractal.org/Samenhang-Industrieel-Ontwerpen/Fractal-Architecture.htm |
Chaos of Disciplines
Chaos of Disciplines uses fractals to explain the patterns of disciplines, and then applies them to key debates that surround the social sciences. Abbott argues that knowledge in different disciplines is organized by common oppositions that function at any level of theoretical or methodological scale. Opposing perspectives of thought and method, then, in fields ranging from history, sociology, and literature, are to the contrary, radically similar; much like fractals, they are each mutual reflections of their own distinctions.
- Contents
1 The Chaos of Disciplines
2 The Duality of Stress
3 The Fraction of Construction
Appendix: A History of "Social Construction" to 1990
4 The Unity of History
5 The Context of Disciplines
Part 2 Two Essays on Self-Similarity
6 Self-Similar Social Structures
Appendix: Fractal Scales
7 The Selfishness of Men
Anthropology: Cultural and Social Anthropology
History: General History
Political Science: Political and Social Theory
Psychology: General Psychology
Sociology: General Sociology | Theory and Sociology of Knowledge
You may purchase this title at these fine bookstores. Outside the USA, see our international sales information. | https://www.press.uchicago.edu/ucp/books/book/chicago/C/bo3641851.html |
Geometry has been a major part of mathematics since the days of the Ancient Greeks. This residential summer school will explore some of the different questions arising from geometrical problems from 2000 years ago to the present day. Participants will meet concepts from university-level mathematics and experience what it is like to study mathematics through formulating problems precisely, looking at examples, generalising and applying logical argument and proof.
Organisation
This summer school is part of the Engineering Development Trust (EDT) Headstart scheme and applications are administered by the EDT.
Applications for 2019 closed on 1st February 2019.
What is it all about?
We will explore topics including:
- Combinatorial geometry: e.g. the construction of the five Platonic solids (and why there can only be five!)
- Topology: how might we formally capture the idea that two different sized squares are "the same shape"? We need to ignore lengths and focus on how shapes are joined together - this is what topology does
- Discrete geometry: if we connect some rods together by some joints when is the result rigid or flexible? This is an interesting pure mathematical problem with some very applicable answers from small scales (understanding atomic lattices and crystals) to the large ones (construction of bridges)
- Fractal geometry: fractals arise when simple geometric patterns are repeated to infinity but surprisingly also occur in nature. Fractals can have dimensions that are not whole numbers!
What will we be doing? | https://www.lancaster.ac.uk/maths/engagement/working-with-schools/headstart-summer-school/ |
Before describing the metrics we use to quantitatively characterize the fractal properties of heart rate and gait dynamics, we first review the meaning of the term fractal. The concept of a fractal is most often associated with geometrical objects satisfying two criteria: self-similarity and fractional dimensionality. Self-similarity means that an object is composed of sub-units and sub-sub-units on multiple levels that (statistically) resemble the structure of the whole object . Mathematically, this property should hold on all scales. However, in the real world, there are necessarily lower and upper bounds over which such self-similar behavior applies. The second criterion for a fractal object is that it have a fractional dimension. This requirement distinguishes fractals from Euclidean objects, which have integer dimensions. As a simple example, a solid cube is self-similar since it can be divided into sub-units of 8 smaller solid cubes that resemble the large cube, and so on. However, the cube (despite its self-similarity) is not a fractal because it has an (=3) dimension. (Click here for a hands-on experiment about fractal curves.)
The concept of a fractal structure, which lacks a characteristic length scale, can be extended to the analysis of complex temporal processes. However, a challenge in detecting and quantifying self-similar scaling in complex time series is the following: Although time series are usually plotted on a 2-dimensional surface, a time series actually involves two different physical variables. For example, in Figure 1, the horizontal axis represents ``time,'' while the vertical axis represents the value of the variable that changes over time (in this case, heart rate). These two axes have independent physical units, minutes and beats/minute, respectively. (Even in cases where the two axes of a time series have the same units, their intrinsic physical meaning is still different.) This situation is different from that of geometrical curves (such as coastlines and mountain ranges) embedded in a 2-dimensional plane, where both axes represent the same physical variable. To determine if a 2-dimensional curve is self-similar, we can do the following test: (i) take a subset of the object and rescale it to the same size of the original object, using the same magnification factor for both its width and height; and then (ii) compare the statistical properties of the rescaled object with the original object. In contrast, to properly compare a subset of a time series with the original data set, we need two magnification factors (along the horizontal and vertical axes), since these two axes represent different physical variables.
To put the above discussion into mathematical terms: A time-dependent
process (or time series) is self-similar if
where means that the statistical properties of both sides of the equation are identical. In other words, a self-similar process, y(t), with a parameter has the identical probability distribution as a properly rescaled process, , i.e., a time series which has been rescaled on the x-axis by a factor a () and on the y-axis by a factor of (). The exponent is called the self-similarity parameter.
In practice, however, it is impossible to determine whether two processes are statistically identical, because this strict criterion requires their having identical distribution functions (including not just the mean and variance, but all higher moments as well). Therefore, one usually approximates this equality with a weaker criterion by examining only the means and variances (first and second moments) of the distribution functions for both sides of Eq. 1.
Figure: Illustration of the concept of self-similarity for a simulated random walk. (a) Two observation windows, with time scales and , are shown for a self-similar time series y(t). (b) Magnification of the smaller window with time scale . Note that the fluctuations in (a) and (b) look similar provided that two different magnification factors, and , are applied on the horizontal and vertical scales, respectively. (c) The probability distribution, P(y), of the variable y for the two windows in (a), where and indicate the standard deviations for these two distribution functions. (d) Log-log plot of the characteristic scales of fluctuations, s, versus the window sizes, n.
Figure 2a shows an example of a self-similar time series. We note
that with the appropriate choice of scaling factors on the x- and y-axis,
the rescaled time series (Fig. 2b) resembles the original time
series (Fig. 2a). The self-similarity parameter defined
in Eq. 1 can be calculated by a simple relation
where and are the appropriate magnification factors along the horizontal and vertical direction, respectively.
In practice, we usually do not know the value of the exponent
in advance. Instead, we face the challenge of extracting this scaling
exponent (if one does exist) from a given time series. To this end it
is necessary to study the time series on observation windows with
different sizes and adopt the weak criterion of self-similarity defined
above to calculate the exponent . The basic idea is
illustrated in Fig. 2. Two observation windows
(Fig. 2a), window 1 with horizontal size and
window 2 with horizontal size , were arbitrarily selected
to demonstrate the procedure. The goal is to find the correct
magnification factors such that we can rescale window 1 to resemble
window 2. It is straightforward to determine the magnification factor
along the horizontal direction, . But for the
magnification factor along the vertical direction, , we need to
determine the vertical characteristic scales of windows 1 and 2. One
way to do this is by examining the probability distributions
(histograms) of the variable y for these two observation windows
(Fig. 2c). A reasonable estimate of the characteristic scales
for the vertical heights, i.e., the typical fluctuations of y, can
be defined by using the standard deviations of these two histograms,
denoted as and , respectively. Thus, we have
. Substituting and into Eq. 2, we
obtain
This relation is simply the slope of the line that joins these two points, (, ) and (, ), on a log-log plot (Fig. 2d).
In analyzing ``real-world'' time series, we perform the above calculations using the following procedures: (1) For any given size of observation window, the time series is divided into subsets of independent windows of the same size. To obtain a more reliable estimation of the characteristic fluctuation at this window size, we average over all individual values of s obtained from these subsets. (2) We then repeat these calculations, not just for two window sizes (as illustrated above), but for many different window sizes. The exponent is estimated by fitting a line on the log-log plot of s versus n across the relevant range of scales. | http://www.physionet.org/tutorials/fmnc/node3.html |
1961. Claudio Arrau's hands. Photo by Arnold Newman. · About · Claudio Arrau (1903 – 1991) one of the greatest pianists of all time, plays Schumann Carnaval (1961). A great person deserves no less: · https://www.youtube.com/watch?v=fSG1CTVD4fo · We need to honor th ...
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Milos Djukicand
2 more people
4 years ago
group_work in beBee Writers
Writing and Editorial Board in Social Networks
As a professor, I also feel the need to boost people. It's my job. · With due respect to all ideas about an advisory editorial board, my opinion is that this approach is not entirely correct. People need to understand that whether it is one voice or one hundred thousand voices, ...
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Fractals, Beauty of Complexity (and Chaos)
Self-similarity (Fractals) on all scales may be the secret key to understanding the complex phenomena. Self-similarity on rather different scales is another proof of fractal nature of cosmology. · Fractal art by Tom Beddard · Multiscale modeling of physical phenomena and matter ...
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Fractals Forever
Be BRAVE, · provide something NEW and magnificent for the others, · then the whole WORLD is yours. · Love is the essence of time. · The moment when we start to believe that we are influential is at the same time the final moment for our own rigorous review, reconsideration and ... | https://rs.bebee.com/bee/milos-djukic/blog |
eCAADe 2020:
Proceedings
FRACAM: A 2.5D Fractal Analysis Method for Facades; Test Environment for a Cell Phone Application to Measure Box Counting Dimension
Talk and Proceeding: eCAADe 2020 - RAnthropologic – Architecture and Fabrication in the cognitive age (Berlin, Germany, 2020 | virtual conference) FRACAM: A 2.5D Fractal Analysis Method for Facades
W Lorenz, G. Wurzer
eCAADe-conference, Berlin, Germany (virtual conference), 2020,
presentation (video)
picnic table
File format: Grasshopper® for Rhinoceros® 5 ... link
CAADRIA 2020:
Proceedings
FLÄVIZ in the rezoning process: A Web Application to visualize alternatives of land-use planning
Talk and Proceeding: CAADRIA 2020 - RE: Anthropocene, Design in the Age of Humans (Chulalongkorn University, Bangkok, Thailand, 2020 | virtual conference) FLÄVIZ in the rezoning process: A Web Application to visualize alternatives of land-use planning
W Lorenz, G. Wurzer
CAADRIA-conference, Bangkok, Thailand (virtual conference), 2020,
presentation (video)
USA Chicago Exkursion 2019
Japan Exkursion 02.07.-17.07.2019 (book) W.E. Lorenz, A. Faller (Hrsg.). Mit Beiträgen der Teilnehmerinnen und Teilnehmer der Exkursion nach "Chicago" (2019).
ISBN: 978-3-9504464-2-5
Das Buch beschreibt in einzelnen Kapiteln die vom Institut Architekturwissenschaften, Digitale Architektur und Raumplanung, organisierte Exkursion nach Chicago aus dem Jahr 2019. ...
Stegreifentwerfen "gesteckt nicht geschraubt 2.0"
digitales Stegreifentwerfen
G. Wurzer, W.E. Lorenz, S. Swoboda. Im Zuge der Lehrveranstaltung wird die Digitalisierung vom Entwurfsprozess bis zur Produktion an Hand einer selbsttragenden Holzstruktur untersucht: vom Stadtmöbel über die Skulptur zur Brücke. ...
I. Introduction
... Clouds are not spheres, mountains are not cones, coastlines are not circles, and bark is not smooth ...
This quotation by Mandelbrot shows that the Euclidean geometry - the perfect “clinical” shapes of cones, pyramids, cubes and spheres - is not the best way to describe natural objects. Clouds, mountains, coastlines and bark are all in contrast to Euclidean figures not smooth but rugged and they offer the same irregularity in smaller scales, which are some important characteristics of fractals - see chapter “2.2 Characteristics”. As the following pages indicate, fractal geometry, in opposition to Euclidean geometry, offers better methods for description or for producing similar natural-like objects respectively. The language in which it is expressed is called “algorithms”, by which complex objects like a fern or a cloud can be reduced to simpler formulas or transformation rules respectively. Fractals can be found everywhere from coastlines, border-lines and other natural rough lines to clouds, mountains, trees, plants, ... and maybe also in architecture. The following chapters explain what a fractal is in general and how fractals can be used for architectural analysis and in the stage of planning. Fractals are used as a helping tool for explanation in many fields ranging from medicine to economy. From this point of view fractals should not be excluded from architecture.
1.1 Mandelbrot - Fractals - Theories and Explanations
... Fractals will make you see everything differently. ... You risk the loss of your childhood vision of clouds, forests, galaxies, leaves, flowers, rocks, mountains, torrents of water, carpets, bricks, and much else besides
The computer-scientist Benoit Mandelbrot introduced the word "fractal" in the year 1975 to describe irregular, not smooth, curves. Fractal geometry in general has become more and more popular since Benoit Mandelbrot’s book “The Fractal Geometry of Nature ” was published for the first time in 1977 and the “Mandelbrot set” was defined in the year 1980. Since that time many of those computer-pictures and "monster curves", as Benoit Mandelbrot called curves with unusual characteristics such as the Koch curve, have been published - some of them will be introduced in chapter “3 Different Fractals”. They were mostly created with a mathematical background, but they can also be found in art because of their beautiful interesting appearance . In the eighties of the 20th century the “Mandelbrot set” could be found in many scientific journals last but not least because of its beauty - this kind of visualizing was, however, only made possible by the quick development of the computer. Subsequently today it is no problem for any of us to produce classical and natural looking fractals quickly and easily on the computer at home. Of course it is dangerous to think that we know enough about fractal geometry and the mathematical background so that we can start to use this "new" geometry in every field of our life. But, are we not now - with all the background of our society - in a position where we can deal with all the questions arising from the use of these new scientific theories and is this not more important than putting all the priority on finding the final result at the moment. To use new theories first means to define how they can help in a specific field and then to find applications in the next step. These days we can already look into other possible fields of application of fractal geometry: natural science, medicine, market analysis, manufacturing, ecology - and architecture? In any case architects and city-planners already use concepts and phrases for analysis which come from other fields, such as the biological metaphor: the city as an organism with the “heart" for the central business district, the “lung" for the green space, the “arteries and veins” for the hierarchy of communications routes - in this connection fractal geometry might provide a new vocabulary which explains the complexity of a city in a better way.
1.2 An Overview
We can describe mountains, clouds, trees and flowers by models consisting of simpler geometric forms based on Euclidean geometry, for example using net models in CAD, but are they exactly what nature is
The first two chapters below give an introduction to fractals and fractal geometry in a more general way, listing characteristics and explaining some examples. Then one chapter follows about the differences between Euclidean and fractal geometry and their expressions in the Euclidean and fractal dimension, introducing and explaining some measuring-methods of the fractal dimension. Until a short time ago scientists described nature through so called “smooth” continuous mathematics, which is the mathematics of smooth forms such as lines, curves and planes and which is expressed in the language of Euclidean geometry. The “new” science of complexity does not try to simulate any more the rugged character of nature through smooth forms but it deals with the raggedness of the structure itself - this field of mathematics is expressed in the language of fractal geometry:
“The whole is more than its parts”. The fractal new geometric art shows surprising kinship to Grand Master paintings or Beaux Arts architecture. An obvious reason is that classical visual arts, like fractals, involve very many scales of length and favor self-similarity .
Chapter “5 Fractals and Architecture” to chapter “6 Fine Arts and City Planning” deal with the question if fractal geometry can be used in architecture and for the analysis of cities or at least with the question in which ways further research can be done - it lists the possible applications of fractal-theory in fine-art, city-planning and architecture, with regard to analytical, formal and practical aspects. Fractal geometry may help us to understand and analyze complexity that can be found in towns of the Middle Ages but also in cathedrals and other man-made objects up to these days. It may also help us to transfer this complexity, which also arises from the development over time, to newly planned cities and buildings - cities and buildings may then also be reduced to simpler algorithms: the automatic architect ? Among other themes one part of chapter “5 Fractals and Architecture” deals with the so called “organic” architecture. In this context, natural structures, explained through fractal geometry, could serve as easy-to-use models for a new “organic”, natural-like architecture. The underlying structure, the character of a building will then follow the principles of fractal geometry that can be found in natural elements. This results in a connection between architecture and nature not only in a formal respect - e.g. with Antoni Gaudí - but also in the complexity of forms and in its character of self-similarity, irregularity and roughness - e.g. with Bruce Goff. Another section of this chapter deals with the question of the quality of buildings, which means asking why one building is regarded as "good" architecture while the other is regarded as "bad" architecture. It is clear that everyone has his or her personal access to architecture and evaluates buildings in a different manner. But there are buildings, which are more interesting in general than others, or there are buildings, which are more noticeable to most people than others - e.g. the acceptance of Gothic, which is related to fractal geometry, in contrast to the resentment towards modern buildings, which are related to Euclidean geometry. Subsequently the idea arises that maybe it is complexity that modern buildings lack. Chapter “7 Problems with Measuring” deals with measuring problems arising from the use of different computer-programs for calculating the box-counting dimension introduced in chapter “4 Dimensions”. Finally, this box-counting dimension is used in chapter “9 Statistics” to get a classification of elevations and ground plans of buildings and cities. In this context the fractal dimension is applied as an indication for roughness.
Footnotes
Comparison of natural objects with Euclidean geometry by the mathematician Benoit Mandelbrot in "The Fractal Geometry of Nature". Bovill Carl, Fractal Geometry in Architecture and Design (1996), Birkhäuser Bosten, ISBN 3-7643-3795-8, p.4, Mandelbrot Benoit B., Dr. Zähle Ulrich (editor of the german edition), Die fraktale Geometrie der Natur (1991) einmalige Sonderausgabe, Birkhäuser Verlag Berlin, ISBN 3-7643-2646-8, p.13. | https://www.welo.at/research-publications/master-thesis/i-introduction/?L=0 |
Mai 36 Galerie is pleased to present new works from the series Negative and d.o.pe. by Thomas Ruff (born 1958 in Zell am Harmersbach/Schwarzwald). Thomas Ruff lives and works in Düsseldorf and has been one of the most important international contemporary artists over the last 40 years.
March 31 – May 27
Artist Reception: Thursday, March 30, 6pm
Since the late 1970s, Thomas Ruff has been investigating the internal rules and structures of the medium of photography throughout various series. In doing so, he is equally interested in both the various genres of photography and the different photographic techniques. He analyzes the photographic genres, which include portraits, landscape, architecture, astronomy, press photos, nudes, or abstraction, for their visual meaning and expressiveness. In doing so, he uses all photographic techniques and methods known to him - analog and digital photographs, images created on the computer, as well as found photographs from books, magazines, newspapers, scientific or private archives, and images circulating on the Internet.
In his exhibition at Mai 36 Galerie, Thomas Ruff presents his latest series d.o.pe. for the first time in Switzerland, exploring the visual appearance of geometric structures, for which the mathematician Benoît Mandelbrot introduced the term ‘fractal’ in 1975. These are ‘naturally’ appearing objects, structures or patterns that exhibit a high degree of self-similarity, so that when a section of the pattern is enlarged, the same structure can be seen again and again. Using fractal software, he created a wide variety of images of sections of the so-called Mandelbrot set, which he then superimposed to create psychedelic pseudo-imitations of nature. He has the finished motif printed on velour rugs, to be hung on the wall as ‘tapestries’, suggesting a seemingly spatial depth and a soft nature-like surface. With this series, Ruff succeeds, on the one hand, in making visible the visual beauty of mathematics, which becomes apparent when immersed in the fractal world, and, on the other hand, in generating images that appear natural but are completely artificially produced.
With the d.o.pe. series, Ruff once again delves into the world of mathematics after the zycles, exploring the visual beauty of complex mathematical formulas and algorithms. If the zycles are visualizations of formulas from the field of linear algebra, the fractal patterns underlying d.o.pe. are extensions of Euclidean geometry. The self-similar structures of fractals occur in simplified form in nature, for example the structure of a snowflake, but they can also be created as a digital image in virtual space in both two and three dimensions. The link, that fractals are both natural and artificial structures at the same time, was confirmed by the artist in his ongoing investigation of human perception. What is reality? The world that is in front of the eye or a constructed, virtual reality. And what if real reality and constructed fiction become indistinguishable?
Additionally, Thomas Ruff is showing for the first time the neg◊laviniaschulz subgroup from the series of Negative - expressionist dance studies of the dancer Lavinia Schulz and the actor Walter Holdt in full-body masks, which they both designed together in the early 1920s. The starting point of the series are photographs of the 19th and 20th century, which have a typical brown patina and whose motifs cover the entire range of historical photography. When these photographs are inverted (reversing the positive into the negative), a high-contrast blue tone emerges, and the compositional design comes to the fore. Thus, the negative, the actual ‘original’ of a photograph, which threatens to disappear completely due to the triumph of digital photography, becomes the object of contemplation.
Over the last 5 years, Thomas Ruff has exhibited in galleries and major museums worldwide, most recently at the MAMC, Musée d'Art Moderne et Contemporain in Saint-Étienne. The close collaboration with Mai 36 Galerie, which regularly exhibits new works by the artist, dates back to 1988. | https://www.mai36.com/exhibitions/03-31-2023-thomas-ruff |
Fractals [a pattern that repeats itself at different scales] and geometric shapes have been used for centuries in Africa to design textiles, sculptures, architecture, hair and more. A simple shape repeated becomes a striking work of art.
- Screen printed geometric design onto white cotton linen blend fabric.
- The design features on both sides of the cushion.
- Bold and stylish this geometric pillow makes a statement on the sofa, armchair, bed or even the floor.
- Pair it with our harvest colour cushion or mix designs with our Tribal Cushion. | https://safarifusion.com.au/collections/cushions/products/facet-cushion-black |
In the words of B. B. Mandelbrot's contribution to this important collection of original papers, fractal geometry is a "new geometric language, which is geared towards the study of diverse aspects of diverse objects, either mathematical or natural, that are not smooth, but rough and fragmented to the same degree at all scales." This book will be of interest to all physical and biological scientists studying these phenomena. It is based on a Royal Society discussion meeting held in 1988.
Originally published in 1990.
ThePrinceton Legacy Libraryuses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These paperback editions preserve the original texts of these important books while presenting them in durable paperback editions. The goal of the Princeton Legacy Library is to vastly increase access to the rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905.
Instead of attempting to introduce and link together the papers that follow in this Discussion Meeting, we prefer to ponder the question, ‘What is fractal geometry?’ We write primarily for the comparative novice, but have tried to include tidbits for the already informed reader.
Before we tackle what afractalis, let us ponder what a fractalis not. Take a geometric shape and examine it in increasing detail. That is, take smaller and smaller portions near a point P, and allow every one to be dilated, that is, enlarged to some prescribed overall size. If our shape belongs to...
Typical fractals are characterized by structure on all scales of length (Mandelbrot 1977). Simple idealized examples much as the recursively constructed Cantor bar, Koch curve, or Sierpiński gasket (figure 1) go into (parts of) themselves under discrete scale changes, so having the property of ‘discrete’ self-similarity. Regular fractals with this property can occur naturally, for example in the spectra of incommensurate systems (Hofstadter 1976). However, real fractals are more often random and typically statistically self-similar. An example is the percolation network (figure 2), which will be discussed in §2.
The property of continuous, or discrete, or statistical, self-similarity is sufficient...
Fractal patterns typically appear in systems that develop far from equilibrium. These patterns are often interpreted by kinetic models, the properties of which are usually known only through computer simulation. In their simplest form, kinetic models do not allow for structural rearrangement and therefore do not yield minimum energy configurations. By contrast, the more common thermodynamic models describe growth phenomena close to equilibrium. These models involve parameters for the surface and bulk energy, and predict compact non-fractal structures.
The traditional models for phase separation, nucleation and growth, and spinodal decomposition, are thermodynamic models. These models successfully describe the essential experimental...
Aerogels are monolithic solid materials with an extremely tenuous microscopic structure (Fricke 1985; Vacheret al. 1989a). The most thoroughly investigated aerogels are made of silica. These can be prepared with a porosity as high as 99%. In consequence, they exhibit unusual physical properties, making them suitable for a number of technical applications, such as Cerenkov radiators, supports for catalysts, or thermal and acoustic insulators. Suitably prepared aerogels are also excellent examples of fractal solids (Vacheret al. 1988a). Thus it is both of fundamental and technical interest to determine the structure of aerogels, to investigate the mechanisms of their...
The aggregation of colloids has been the subject of scientific investigations for over 100 years. The past few years have seen considerable progress in our understanding of the complex physics that govern this process. A key to this recent success is the recognition that the structure of the colloidal aggregates exhibits scale invariance or dilation symmetry, and can be described as a fractal (Weitz & Oliveria 1984). This has afforded a quantitative description of the highly disordered structure of the clusters, which has in turn afforded a more detailed description of the kinetic growth process that forms these aggregates.
The class...
An early theory of the kinetics of aggregation, coagulation and precipitation is that of Smoluchowski (1916). Many studies of aggregation (Reerink & Overbeek 1954; Ottewill & Shaw 1966) have made use of this theory to model the initial stages of the reaction. In recent years there has been an upsurge of interest in the study of aggregation because of the discovery of the fractal nature of the aggregates produced in these reactions (Schaefferet al. 1984; Weitz & Oliveira 1983). Large-scale computer simulations of aggregation reactions (Meakin 1983; Kolbet al. 1983) have indicated some departure from ‘Smoluchowski’ kinetics. This has stimulated the...
Mass action kinetics give rise to nonlinear evolution equations for systems of chemical reactions; similarly, fluid flows are governed by nonlinear laws in all but special limiting cases. Even stock markets, it seems, when controlled by computer program, evolve as deterministic nonlinear dynamical systems. The realization that nonlinearities have important consequences on the dynamics of real systems is not new (except, perhaps, in the case of the stockmarket). Over the past century (Poincaré 1899), and particularly over the past two decades (see, for example, Guckenheimer & Holmes 1983; Bergéet al. 1984) there has been a strong interest in the mathematics...
The key element relating different analogues of diffusion-controlled growth (or aggregation) is that the local growth rate is determined by the flux of a field that obeys Laplace’s equation, with the growth surface presenting an equipotential boundary condition. This is evidently realized by true material diffusion in the limit that the growth advances slowly enough that the concentration field ahead of it is quasi-static, and the extreme case of this is represented by the original diffusion limited aggregation (dla) computer model of Witten & Sander (1981) where only one particle approaches the aggregate at any one time.
It is valuable to...
Pattern-formation processes have been of considerable scientific interest and practical importance for many decades. Interest in the growth of complex structures under non-equilibrium conditions has been stimulated by several recent developments. The dissemination of the concepts of fractal geometry (Mandelbrot 1982) and related ideas have provided us with ways of describing a very broad range of irregular structures in quantitative terms. It has been shown that even very simple nonlinear systems and models (see, for example, May 1976; Lorenz 1963; Feigenbaum 1978) can lead to complex, often chaotic, behaviour that can frequently be described in terms of fractal geometry. In...
Electrodeposition has been of much current interest as an experimentally controllable example of growth governed by diffusion. In the ideal experiment the field controlling transport of the depositing species obeys, in the quasi-stationary approximation, Laplace’s equation (Ball 1986). Experimental realizations with this field being the concentration (Brady & Ball 1984; Kaufmanet al. 1987) and also an electric field (Matsushitaet al. 1984, 1985; Grieret al. 1986; Swadaet al. 1986) have been reported. The fractals of the diffusion-limited extreme (Witten & Sander 1983) have been grown (Brady & Ball 1984; Kaufmanet al. 1987; Kahanda & Tomkiewicz 1988). This extreme has been...
The purpose of this paper is to provide better understanding of the relevant mechanisms that control the displacement of a wetting fluid by a non-wetting fluid in a porous medium when both capillary and viscous forces are present.
By using experiments on micromodels and computer simulations, we have previously demonstrated the existence of three types of basic displacements:
(a) capillary fingering when capillary forces are very strong compared to viscous forces;
(b) viscous fingering when a less viscous fluid is displacing a more viscous one;
(c) stable displacement in the opposite case.
We have also shown how these displacements can...
Since the first exploration of fractal surface properties of solids at molecular scales (Avnir & Pfeifer 1983) experimental investigations have uncovered a wealth of materials with a well-defined fractal surface dimensionD(see, for example Avniret al. 1984, 1985; Schaeferet al. 1987; Pfeifer 1987; Schmidt 1988; Farin & Avnir 1989), as determined by a wide variety of techniques. Properties that are sensitive toDinclude small-angle X-ray and neutron scattering (Bale & Schmidt 1984; Wonget al. 1986; Martin & Hurd 1987), multiple scattering and absorption of light (Berry & Percival 1986), electronic energy transfer between adsorbed molecules (Klafter & Blumen 1984; Evenet...
Randomness occurs in many areas of modern physics. For example, in the past decade interest has turned increasingly towards the investigation of amorphous solids such as glasses. There are two reasons why this did not happen earlier: on the one hand these substances are now of technical interest; on the other hand, until recently the lack of suitable theoretical methods prevented a satisfactory description of experimental results. It is clear that models developed for crystalline solids are inappropriate, because they are based upon the translational symmetry of the lattice, and glasses are translationally disordered. Glasses show a number of unusual... | http://slave2.omega.jstor.org/stable/j.ctt7ztsgz |
What is NOT Digital Art?
1 - Neither analogue nor digital photography that have been given only little o basic digital process like colour retouching , contrast, brightness or any other sort of corrections which do not imply a creative and intense work is NOT Digital Art.
2 - Neither analogue nor digital photography to which only ordinary digital effects have been applied (those made by only a click of the mouse when no artist's skills are required). This kind of images may be considered as 'Retouched or Manipulated Photography' or 'Photo Art' but NOT Digital Art.
3 - Any kind of scanned or photographed hand-made artworks like oil paintings, acrylic paintings, watercolour, etc. that have been printed later on any sort of media (canvas, paper, etc.), are NOT Digital Art. This process might be valid for those traditional artists who wish to make reproductions of their original paintings, drawings, watercolours, etc., by printing them as high quality limited series, but such process shoud not be classified as 'Digital Art'.
4 - Those kind of printed images mentioned above to which hand painting is added (oil, acrylic, watercolour, etc.) to get a 'new artwork' is NOT Digital Art, and should be considered as 'Mixed Media' as they have no digital creative process, since they are only printed photos of artworks on which some hand painting has been added.
It is the creation of virtual worlds (= only exist in the computer) through which, you can travel with a virtual camera. In these worlds, you can create objects, texturize, rotate, move and deform them as you wish. Once your project is finished and you are satisfied with it, you ask the computer to render (= the final process of all 3D software; at this point, the processor does the hard job to draw the image in the size and at the highest resolution you want so as to get an optimal quality image output for printing).
Although there has been some research by 1918, fractals have been discovered in 1975 by the Mathematician Benoit Mandelbrot who gave them the name 'fractal' that comes from the Latin word 'fractus' meaning 'fractured'. Fractals can be found in nature: trees, clouds, rivers, coasts, mountains, our circulatory system,... are fractals. They are difficult to define as not all of them meet the same features although they share some: they represent a geometric shape that repeats itself exactly (self-similarity) or with some variations (some of them may be chaotic), zooming in or out to disappear eventually. Coast perimeters, can be calculated with fractal formulas, and they are used in medicine, biology, astronomy, meteorology, etc.... and also fractal music can be created.
Those fractals that have been studied previously (Julia and Mandelbrot sets) get closest to the fractal definition in reference to the fact of having a specific and repetitive pattern. The 'Fractal Flames' and '3D Fractal Flames', developed by Scott Draves in 1991, have a different algorithm, and they differ from the ones previously mentioned, in showing those repetitive self-similar patterns scarcely. The final images are more ethereal, with bright areas, with either abstract or figurative shapes, expanding -this way- the creation boundaries to make them look much more artistic.
There's no need to have a deep Maths knowledge to be able to do 'Fractal Art'. The pieces of software to design fractals allow you to start with a complex formula or from the scratch, and it is the artist who is in control and has to modify amounts, variables and functions to create his fractal images. Colours are also applied by using formulas, and the final fractal depends on the artist and his skills to handle these tools.
'Fractal Art' is the real 'Modern Art' as it is discovered, developed and became a reality since the advent of the computer, as there's no other way to do the many and very complex required calculations without this great technologic tool.
I do some hard POST PRODUCTION work to my 3D Art images: correction of rendering imperfections and, when necessary, brightness and/or contrast adjustments.
I do little POST PRODUCTION work to my Fractal Art images: only brightness and/or contrast adjustments, when necessary. | https://www.aliciadangelica.com.ar/en/arte-digital-art-en.html |
Identification and characterization of highly versatile peptide-vectors that bind non-competitively to the low-density lipoprotein receptor for in vivo targeting and delivery of small molecules and protein cargos.
Insufficient membrane penetration of drugs, in particular biotherapeutics and/or low target specificity remain a major drawback in their efficacy. We propose here the rational characterization and optimization of peptides to be developed as vectors that target cells expressing specific receptors involved in endocytosis or transcytosis. Among receptors involved in receptor-mediated transport is the LDL receptor. Screening complex phage-displayed peptide libraries on the human LDLR (hLDLR) stably expressed in cell lines led to the characterization of a family of cyclic and linear peptides that specifically bind the hLDLR. The VH411 lead cyclic peptide allowed endocytosis of payloads such as the S-Tag peptide or antibodies into cells expressing the hLDLR. Size reduction and chemical optimization of this lead peptide-vector led to improved receptor affinity. The optimized peptide-vectors were successfully conjugated to cargos of different nature and size including small organic molecules, siRNAs, peptides or a protein moiety such as an Fc fragment. We show that in all cases, the peptide-vectors retain their binding affinity to the hLDLR and potential for endocytosis. Following i.v. administration in wild type or ldlr-/- mice, an Fc fragment chemically conjugated or fused in C-terminal to peptide-vectors showed significant biodistribution in LDLR-enriched organs. We have thus developed highly versatile peptide-vectors endowed with good affinity for the LDLR as a target receptor. These peptide-vectors have the potential to be further developed for efficient transport of therapeutic or imaging agents into cells -including pathological cells—or organs that express the LDLR. | https://www.vect-horus.com/VECT-HORUS-demonstrates-the-high-versatility-of-its-peptide-vectors-library-for |
Endocytosis is the process of bringing something into a cell without its passing through the cell membrane via transport. This is particularly important for polar or very large molecules. There are three generally accepted mechanisms for endocytosis: phagocytosis, pinocytosis, and receptor-mediated endocytosis.
All of the processes involve vesicle formation, a “bubble” inside the cell, created from the plasma membrane as the external material is engulfed and brought into the cell. How this vesicle, called an endosome, forms is the difference in the mechanisms.
Phagocytosis
Macrophages are probably the most well-known cells that practice phagocytosis. This is the process by which foreign material and pathogens are “eaten” and digested as the body battles or prevents disease. The cell membrane sends out projections called pseudopodia (‘false feet’). A ligand-receptor interaction tells the cell if it found something that should be engulfed. The pseudopodia extend and the membrane folds around the material. When the two projections meet, the membrane fuses to fully enclose it within the intracellular vesicle, which then pinches off from the main membrane. See an animation of phagocytosis.
The endosome in this case is called a phagosome, or vacuole if very large. The process occurs only in specialized cells. The contents of the phagosome are delivered to lysosomes, vesicles containing enzymes that digest the material.
Pinocytosis
This mechanism is very similar to phagocytosis, except the material being endocytosed is liquid. Instead of pseudopodia, the membrane forms a depression. The material to be engulfed gathers in the cavity, which closes off when the edges of its opening meet, resulting in membrane fusion. The intracellular vesicle is pinched off from the main membrane.
This process occurs continuously in almost all cells and brings in extracellular fluid. A subtype of this process involves caveolae, also known as lipid rafts. They implicate endocytosis in cell signaling and have been associated with cardiovascular functions, among others.
Receptor-mediated endocytosis
A well studied application of this process in the human body is cholesterol (specifically LDL) entry into cells, but iron transport also occurs via this process. Basically, a molecule is recognized by a specific receptor on the cell surface, triggering an intracellular vesicle to fold around the material and pinch off from the membrane. See an animation of receptor-mediated endocytosis.
A subtype of this process is clathrin-mediated endocytosis. Cell surface receptors may be embedded in clathrin-coated pits. Clathrin is an intracellular protein attached to the membrane in regions where the receptors are found. When enough receptors are bound, the vesicle forms, similarly to pinocytosis, but is coated with the clathrin proteins. Therefore, this mechanism of endocytosis results in coated vesicles.
Summary of the cell entry mechanism
Endocytosis is an essential process by which certain materials are brought into the cells. It occurs by recognition of the material and then formation of an intracellular vesicle from the cell membrane. What is done with the material once it is inside the cell depends on the process used to bring it in. Not all cells are capable of every mechanism, though every cell is capable of some form of endocytosis.
See additional animations of the processes by McGraw-Hill. | https://www.sciences360.com/index.php/endocytosis-and-cell-entry-3224/ |
The cytokine interleukin 2 (IL2) is produced by activated helper T lymphocytes and modulates the growth and activity of cells expressing high-affinity surface IL2 receptors that transduce its signaling. After ligand binding to receptors on the plasma membrane, receptor-ligand complexes are rapidly endocytosed and IL2 is degraded in acidic compartments. The best known receptor-mediated endocytosis pathway involves clathrin-coated pits. Receptors that carry an internalization signal recognized by adaptors on the cytosolic side of the plasma membrane are clustered into the coated pits and enter cells very efficiently. Many receptors use this pathway, but other endocytic pathways have also been reported, for ricin, EGF and insulin, for instance, which seem to be less efficient than the coated one. We compared the endocytosis of IL2 and its receptors to that of transferrin, a marker of the coated pit pathway. Under normal conditions, the kinetics of entry of IL2 was two times slower than that of transferrin. When internalization via coated pits was inhibited by two different methods, potassium depletion and cytosol acidification, endocytosis of IL2 and its receptors was only partly inhibited, while transferrin entry was strongly affected. Treatment with the cationic amphiphilic drug chlorpromazine, which induces a redistribution of a clathrin-coated pit component, AP-2, to endosomes, reduced transferrin, but not IL2 internalization. Thus, unexpectedly, this cytokine and its receptors can still be rapidly endocytosed in the absence of functional clathrin-coated structures. We propose a model for receptor-mediated endocytosis that may account for these results and published data on other receptors.
Rapid endocytosis of interleukin 2 receptors when clathrin-coated pit endocytosis is inhibited
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A. Subtil, A. Hemar, A. Dautry-Varsat; Rapid endocytosis of interleukin 2 receptors when clathrin-coated pit endocytosis is inhibited. J Cell Sci 1 December 1994; 107 (12): 3461–3468. doi: https://doi.org/10.1242/jcs.107.12.3461
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Endocytosis and exocytosis are two major forms of vesicular transport. Endocytosis brings molecules and other substances into the cell. In exocytosis, synthesized molecules and other substances leave the cell. Endocytosis is associated with the formation and budding of vesicles from the plasma membrane; exocytosis is associated with the fusion of vesicles originating from intracellular organelles with the plasma membrane and is a primary secretory modality.
formed by virtually every cell in the organism, and it is constitutive; i.e., it involves a continuous dynamic formation of small vesicles at the cell surface (Fig. 2.9a). Recent studies indicate that mechanoenzymes such as GTPase (dynamin) are involved in pinocytotic vesicle scission (the process of pinching off from the plasma membrane). Pinocytotic vesicles are visible with the TEM, and they have a smooth surface. These smooth pinocytotic vesicles are especially numerous in the endothelium of blood vessels (Fig. 2.9b) and in smooth muscle cells. Pinocytosis does not require clathrin and therefore may be referred to as clathrin-inclependent endocytosis.
• Receptor-mediated endocytosis allows entry of specific molecules into the cell. In this mechanism, receptors for specific molecules, called cargo receptors, accumulate in
Was this article helpful? | https://www.guwsmedical.info/muscle-cells/figure-28.html |
What is an antigen?
Molecules (usually proteins) that stimulates an immune response when detected by body
Describe how lymphocytes recognise self from non-self
- Each lymphocyte recognises a different chemical shape
- They collide with body’s own material (self)
- Some lymphocytes have receptors that fit body’s cells
- These either die or are suppressed
- Remaining fit only foreign material
- These either die or are suppressed
- Remaining fit only foreign material
Name the 4 main stages of immune response
- Phagocytosis
- Phagocytes Activate T-cells
- T-cells Activate B-cells, which divide into Plasma cells
- Plasma cells make more Antibodies to a Specific Antigen
Where are phagocytes found?
In blood and tissues
Describe phagocytosis (5)
- Phagocyte recognises (foreign) antigen
- Phagocyte engulfs pathogen
- Enclosed in vacuole/phagosome
- (Vacuole) fuses with lysosome
- Lysosome contains enzymes (lysozymes) that hydrolyse pathogen
Why does phagocytes moves towards pathogens?
∵ they're attracted to pathogen's chemical products
Phagocytes engulf pathogens by _____
endocytosis
Waste products removed by _____
exocytosis
How do lysozymes break down bacteria?
Hydrolyse the cell walls of bacteria
What do phagocytes do at the end of phagocytosis?
Phagocyte presents pathogen's antigens on its surface to activate other immune system cells
What do T-cells only respond to?
Antigen-presenting cells
Where do T-cells (aka T-lymphocyte) mature?
In thymus gland
Describe what T-cells do
- Respond to antigens on foreign and infected cells
- Specific receptors on helper T cells bind to specific antigen presented by phagocytes (antigen-presenting cell)
- This activates T-cell: Binding triggers rapid mitosis = T cells are cloned
Name 4 things that the cloned helper T-cells do
- Activate cytotoxic T cells
- Activate B-cells to divide and secrete their antibodies
- Develop into memory cells
- Release chemical signals that activate and stimulate phagocytes
Describe how cytotoxic T-cells kill infected cells
- Produce protein called perforin that makes holes in cell-surface membrane
- Holes means cell membrane becomes freely permeable
- Control of substances no longer controls and cell dies
Why is the action of T-cells most effective against viruses?
∵ they replicate inside cells, sacrificing these body cells prevents viruses from multiplying and infecting more cells
What is the role of macrophages in stimulating B lymphocytes?
- Antigen in membrane presented to lymphocytes
- Produce cytokinins
What are B-cells (B-lymphocytes)?
White blood cell that's covered with antibodies
What are antibodies?
- Proteins that bind antigens to form antigen-antibody complex
- Stimulate immune response
- Stimulate immune response
Describe how T-cells activate B-cells, which divide into plasma cells
- When antibody on surface of B-cells meets complementary shaped antigen = binds to it
- This, together with chemicals released from helper T-cells, activates B-cell = divides by mitosis
- Clonal selection: form clones/produce plasma cells
- Make antibodies
- Plasma cells produce memory cells
What do plasma cells do?
Secrete loads of antibodies specific to antigen
callled monoclonal antibodies
Describe what antibodies do to destroy pathogens
- Antibody has 2 binding sites = can bind 2 pathogens at same time
- Means pathogens & antibodies become clumped together = called agglutination
- Phagocytes bind to antibodies and phagocytose many pathogens at once
- Process leads to destruction of pathogens carrying this antigen in body
All antibodies have same _____ region
All antibodies have same constant region
What does the constant region allow antibodies to do?
To bind to receptors on B-cells
What does the hinge region allow antibodies to do?
Allows flexibility so molecules can group more than one antigens
Why are antibodies specific to one antigen? (3)
- Variable region has specific primary structure
- Tertiary structure of binding site is complementary to bind with these antigens
- Forms complex between antigen and antibody
What is the primary response?
When antigen enters body for 1st time & activates immune system
Why is the primary response slow? | https://blog.brainscape.com/flashcards/325-the-defensive-functions-of-mammalian-7650227/packs/11498561 |
MedLine Citation:
|PMID: 6092118 Owner: NLM Status: MEDLINE|
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Abstract/OtherAbstract:
|The interaction of ceruloplasmin (CP) with isolated liver cell suspensions was studied using 125I-labeled and latex minibead-derivatized CP. Fractionation of liver cell suspensions was done using metrizamide gradient centrifugation. In crude liver cell suspensions only endothelial cells, but not hepatocytes and Kupffer cells bound the minibead probe. The binding was specific and inhibited by excess native CP. These results were confirmed using 125I-CP combined with cell fractionation technique. Kinetic data, obtained from the latter system, indicated a dissociation constant (Kd) of 1 X 10(-7) M and the number of receptors to be 5.7 X 10(5) per endothelial cell. The exclusive binding of CP to liver endothelium suggests that this cell may mediate the hepatocytes uptake of CP and is, therefore, a crucial element of the tissue-blood barrier.|
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Authors:
|M Kataoka; M Tavassoli|
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Publication Detail:
|Type: Journal Article; Research Support, U.S. Gov't, P.H.S.|
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Journal Detail:
|Title: Experimental cell research Volume: 155 ISSN: 0014-4827 ISO Abbreviation: Exp. Cell Res. Publication Date: 1984 Nov|
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Date Detail:
|Created Date: 1984-12-07 Completed Date: 1984-12-07 Revised Date: 2007-11-14|
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Medline Journal Info:
|Nlm Unique ID: 0373226 Medline TA: Exp Cell Res Country: UNITED STATES|
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Other Details:
|Languages: eng Pagination: 232-40 Citation Subset: IM|
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Export Citation:
|APA/MLA Format Download EndNote Download BibTex|
|MeSH Terms|
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Descriptor/Qualifier:
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Animals
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Ceruloplasmin / metabolism*
Endothelium / metabolism*
Liver / cytology, enzymology, metabolism*
Male
Rats
Rats, Inbred Strains
Receptors, Cell Surface / metabolism*
|Grant Support|
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ID/Acronym/Agency:
|AM-30142/AM/NIADDK NIH HHS|
|Chemical|
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Reg. No./Substance:
|0/Receptors, Cell Surface; EC 1.16.3.1/Ceruloplasmin|
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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A transmembrane protein belonging to the tumor necrosis factor superfamily that specifically binds RECEPTOR ACTIVATOR OF NUCLEAR FACTOR-KAPPA B and OSTEOPROTEGERIN. It plays an important role in regulating OSTEOCLAST differentiation and activation.
Receptor Activator of Nuclear Factor-kappa B
A tumor necrosis factor receptor family member that is specific for RANK LIGAND and plays a role in bone homeostasis by regulating osteoclastogenesis. It is also expressed on DENDRITIC CELLS where it plays a role in regulating dendritic cell survival. Signaling by the activated receptor occurs through its association with TNF RECEPTOR-ASSOCIATED FACTORS.
Osteoprotegerin
A secreted member of the TNF receptor superfamily that negatively regulates osteoclastogenesis. It is a soluble decoy receptor of RANK LIGAND that inhibits both CELL DIFFERENTIATION and function of OSTEOCLASTS by inhibiting the interaction between RANK LIGAND and RECEPTOR ACTIVATOR OF NUCLEAR FACTOR-KAPPA B.
Osteoclasts
A large multinuclear cell associated with the BONE RESORPTION. An odontoclast, also called cementoclast, is cytomorphologically the same as an osteoclast and is involved in CEMENTUM resorption.
Ligands
A molecule that binds to another molecule, used especially to refer to a small molecule that binds specifically to a larger molecule, e.g., an antigen binding to an antibody, a hormone or neurotransmitter binding to a receptor, or a substrate or allosteric effector binding to an enzyme. Ligands are also molecules that donate or accept a pair of electrons to form a coordinate covalent bond with the central metal atom of a coordination complex. (From Dorland, 27th ed)
Receptors, Tumor Necrosis Factor
Osteitis Deformans
A disease marked by repeated episodes of increased bone resorption followed by excessive attempts at repair, resulting in weakened, deformed bones of increased mass. The resultant architecture of the bone assumes a mosaic pattern in which the fibers take on a haphazard pattern instead of the normal parallel symmetry.
Receptors, Cytoplasmic and Nuclear
Intracellular receptors that can be found in the cytoplasm or in the nucleus. They bind to extracellular signaling molecules that migrate through or are transported across the CELL MEMBRANE. Many members of this class of receptors occur in the cytoplasm and are transported to the CELL NUCLEUS upon ligand-binding where they signal via DNA-binding and transcription regulation. Also included in this category are receptors found on INTRACELLULAR MEMBRANES that act via mechanisms similar to CELL SURFACE RECEPTORS.
Carrier Proteins
Glycoproteins
Conjugated protein-carbohydrate compounds including mucins, mucoid, and amyloid glycoproteins.
Osteoporosis
Reduction of bone mass without alteration in the composition of bone, leading to fractures. Primary osteoporosis can be of two major types: postmenopausal osteoporosis (OSTEOPOROSIS, POSTMENOPAUSAL) and age-related or senile osteoporosis.
Osteoblasts
Bone and Bones
A specialized CONNECTIVE TISSUE that is the main constituent of the SKELETON. The principle cellular component of bone is comprised of OSTEOBLASTS; OSTEOCYTES; and OSTEOCLASTS, while FIBRILLAR COLLAGENS and hydroxyapatite crystals form the BONE MATRIX.
CD40 Ligand
A membrane glycoprotein and differentiation antigen expressed on the surface of T-cells that binds to CD40 ANTIGENS on B-LYMPHOCYTES and induces their proliferation. Mutation of the gene for CD40 ligand is a cause of HYPER-IGM IMMUNODEFICIENCY SYNDROME, TYPE 1.
Signal Transduction
The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.
Cell Differentiation
Fas Ligand Protein
A transmembrane protein belonging to the tumor necrosis factor superfamily that was originally discovered on cells of the lymphoid-myeloid lineage, including activated T-LYMPHOCYTES and NATURAL KILLER CELLS. It plays an important role in immune homeostasis and cell-mediated toxicity by binding to the FAS RECEPTOR and triggering APOPTOSIS.
Cells, Cultured
Protein Binding
Binding Sites
Models, Molecular
Molecular Sequence Data
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
Amino Acid Sequence
TNF-Related Apoptosis-Inducing Ligand
A transmembrane-protein belonging to the TNF family of intercellular signaling proteins. It is a widely expressed ligand that activates APOPTOSIS by binding to TNF-RELATED APOPTOSIS-INDUCING LIGAND RECEPTORS. The membrane-bound form of the protein can be cleaved by specific CYSTEINE ENDOPEPTIDASES to form a soluble ligand form.
CD30 Ligand
Osteoporosis, Postmenopausal
Postmenopause
Bone Density
The amount of mineral per square centimeter of BONE. This is the definition used in clinical practice. Actual bone density would be expressed in grams per milliliter. It is most frequently measured by X-RAY ABSORPTIOMETRY or TOMOGRAPHY, X RAY COMPUTED. Bone density is an important predictor for OSTEOPOROSIS.
Estrogens
Compounds that interact with ESTROGEN RECEPTORS in target tissues to bring about the effects similar to those of ESTRADIOL. Estrogens stimulate the female reproductive organs, and the development of secondary female SEX CHARACTERISTICS. Estrogenic chemicals include natural, synthetic, steroidal, or non-steroidal compounds.
Bone Marrow Cells
Antibodies
Immunoglobulin molecules having a specific amino acid sequence by virtue of which they interact only with the ANTIGEN (or a very similar shape) that induced their synthesis in cells of the lymphoid series (especially PLASMA CELLS).
Prosthesis-Related Infections
Joint Prosthesis
Bone Remodeling
The continuous turnover of BONE MATRIX and mineral that involves first an increase in BONE RESORPTION (osteoclastic activity) and later, reactive BONE FORMATION (osteoblastic activity). The process of bone remodeling takes place in the adult skeleton at discrete foci. The process ensures the mechanical integrity of the skeleton throughout life and plays an important role in calcium HOMEOSTASIS. An imbalance in the regulation of bone remodeling's two contrasting events, bone resorption and bone formation, results in many of the metabolic bone diseases, such as OSTEOPOROSIS. | https://lookformedical.com/en/definitions/rank-ligand |
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Chapter 1 : History and Practice: Antibodies in Infectious Diseases
Category: Clinical Microbiology
History and Practice: Antibodies in Infectious Diseases, Page 1 of 2< Previous page | Next page > /docserver/preview/fulltext/10.1128/9781555817411/9781555817350_Chap01-1.gif /docserver/preview/fulltext/10.1128/9781555817411/9781555817350_Chap01-2.gif
Abstract:
Antibodies in Infectious Diseases aims to inform, update, and inspire students, teachers, researchers, pharmaceutical developers, and health care professionals on the status of the development of antibody-based therapies for treating infectious diseases and the potential for these in times of growing antibiotic resistance to provide alternative treatment solutions to the currently used antibiotics and new treatments for infectious diseases where no proper treatments are available.
Figures
Figure 1
(Left panel) Model of antibody structure exemplified by IgG. On top the antigen-binding sites in orange each contain one variable light and variable heavy domain with the three complementarity determining regions (CDRs) that are responsible for the specific binding of the antibody to its target. For each arm of the antibody, an additional set of variable heavy and light domains, together with the CDR-containing domains, represent the two fragment antigen binding (Fab) regions. The two Fabs are held together via two disulfide bridges. Below the Fabs is the Fc region, which contains four constant heavy domains. On the upper pair of these domains are binding sites for oligosaccharides, which have major importance for the ability of the antibody Fc part to trigger effector functions when the Fc portion is bound to Fc gamma receptors on natural killer cells, neutrophil granulocytes, monocytes/macrophages, dendritic cells, and B cells. (Right panel) Examples of some of the antibody-derived alternative formats used to exploit the specific features of the CDRs, the Fabs, and the Fc parts of the antibodies. ScFv: The single chain fragment variable consists of the variable domains of the heavy and light chains held together by a flexible linker. This can also be used as a carrier of a cytotoxic drug in a so-called antibody drug complex (ADC) where the specificity of the ScFv is used to target the cytotoxic drug to, e.g., a tumor. Bite (bi-specific T cell engager): Fusion proteins consisting of two ScFvs, one directed against the target on a tumor cell and the other against the T cell receptor (CD3). Diabody: ScFv dimers where short linker peptides (five amino acids) ensure dimerization, and not folding, of the ScFvs. Fab and F(ab)2 fragments: Single Fab fragments or fragments containing two Fabs linked via disulfide bridges. This is used where effector functions related to the Fc part of the antibody are unwanted and where a smaller size is desired to obtain better tissue penetration in, e.g., tumors. Due to the lack of the FcRn binding via the Fc part, Fab and F(ab)2 fragments have much shorter half-lives (hours or days) than full-size antibodies (weeks). These can also be used as carriers of cytotoxic payloads or cytotoxic radioactive isotopes and for the F(ab)2 fragments can be constructed as bi-specifics which can cross-link immune cells and target cells. Fc fusion protein: Fusion protein containing the Fc domain of an immunoglobulin bound to a peptide. The peptide can be a ligand for a specific receptor on a target cell or a blocking peptide for a soluble ligand. The Fc part provides a longer half-life to the construct and the potential to bind to and engage effector functions in the killing of, e.g., tumor cells or infected cells. ADCs/RIAs and bi-specifics: Full-size IgG antibodies carrying either a cytotoxic chemical or radioactive payload, which may also carry different CDRs, enabling cross-linking of effector and target cells for increased killing.
Figure 2
Effector functions of antibodies. (a) Antibodies bind to pathogen-derived or endogenous antigens expressed on the surface of an infected cell, which triggers binding to Fc receptors on natural killer cells and lysis of the infected cell by antibody-dependent cellular cytotoxicity. (b) Antibodies bind to pathogen-derived or endogenous antigens expressed on the surface of infected cells, which triggers activation of complement through binding of complement factor C1q. (c) Neutralization. Top: Bacterial toxin neutralized by bound antigen. Bottom: Antibody bound to either receptor for the virus or to the virus itself, which blocks virus binding and entry into the cell. (d) Antibody bound to viral surface proteins binds to Fc receptors on phagocytic cells, e.g., macrophages, and triggers endocytosis and destruction of virus in endolysosome. | https://www.asmscience.org/content/book/10.1128/9781555817411.chap1 |
B cells, also known as B lymphocytes, play an important role in our survival. They function as part of the adaptive immune system and work by producing the necessary antibodies which are specific to the antigens on the surface of invading pathogens. Early B cell development occurs in the foetal liver, and then throughout adult life, B cells are developed from haematopoietic stem cells found in the bone marrow. that express PAX5 transcription factor. PAX5 is a protein that is encoded in the PAX5 gene that is responsible for encoding for the protein (BSAP) that is expressed at early stages of B cell differentiation.
B cells have receptors on their surface known as 'B cell receptors' (BCR) which bind to foreign antigens and become activated. The activation of the B cell causes it to proliferate and differentiate into either a plasma cell or a memory cell. Plasma cells secrete antibodies; memory cells ensure cells can be quickly reactivated and generate more plasma cells when the cell comes into contact with the same antigen from the primary response. Memory cells are can be activated and generate a secondary response even decades after the primary response occurred. This means there is no need for constant stimulation or re-exposure of the B cell to foreign antigens.
A B cell which has not come into contact with a foreign antigen before in its lifespan is called a naive B cell, and when it becomes activated it is a mature B cell. Once B cells mature, they are released from the bone marrow and travel into the lymphatic system. Mature B cells enter germinal centres within the lymph nodes and during proliferation, the genes which encode antibodies undergo somatic hypermutation. This is the process where antibodies become more specific to foreign antigens which means the response will be quicker and more efficient. Specifically, the hypervariable regions undergo mutation at a very high rate in the hope of generating antibodies which bind more tightly to antigens. Somatic hypermutation is only able to occur via key enzymes that allow random mutations across the variable regions, which are then 'fixed' by activation-induced deaminase and DNA repair genes, these amongst other enzymes allow BCR's to have a vast range of genetic coding and therefore enables our immune system to work at a much higher level.
B cells which elicit a response to self-antigens are destroyed by apoptosis. If they could be activated, this would lead to autoantibodies being produced and autoimmune disease.
Activation
B cells require a two signal activation process, so they are not activated accidentally or without reason.
The first signal is generated by the antigen binding to the BCR. BCR-associated Ig alpha and beta, especially the immunoreceptor tyrosine-based activation motif (ITAM) are involved in signalling . The second signal is generated by two different mechanisms depending on which antigen is present. There are two different types of antigen: thymus-dependent antigens (TD) and thymus-independent antigens (TI). T-dependent antigens require a T-helper cell to generate the second signal, whereas T-independent antigens do not.
T-independent antigens such as lipopolysaccharides on bacterial cells bind to toll-like receptors (TLRs) on the surface of the B cell, or cross-linking between BCR and bacterial cell wall constituents occurs. This generates the second activation signal. This results in a rapid primary response, however, antibodies bind less specifically and with less affinity.
T-dependent antigens take in the antigen through receptor-mediated endocytosis. The antigen is processed and displayed as peptide fragments along with the MHC class II molecules on the surface of the B cell. T-helper cells (follicular T-helper cells) bind to this complex via their receptors (TCR) which generates the second signal for the B cell to be activated. The second signal, caused by the interaction between the naïve B cell presenting the MHC molecule and the T-Helper cell occurs via a ligand binding. The T cell presents a CD40L (ligand), which then binds to a CD40 molecule on the B cell. This interaction then activates the T cell to release cytokines that can then bind to the B cell. Both the ligand and cytokine binding to the B cell allow activation. | https://teaching.ncl.ac.uk/bms/wiki/index.php/B_Cell |
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Journal Articles
Annexin I is phosphorylated in the multivesicular body during the processing of the epidermal growth factor receptor.
J Cell Biol (1993) 120 (1): 77–83.
Published: 01 January 1993
Abstract
We have previously shown that an active epidermal growth factor receptor (EGF-R) kinase is necessary for efficient sorting of the EGF-R to the lysosome, and we have shown that this occurs in the multivesicular body (MVB), where EGF-R are sorted away from recycling receptors by being removed to the internal vesicles of the MVB. The aim of the present study was to identify substrates of the EGF-R kinase associated with MVBs which might play a role in this sorting process. We used a density shift technique to isolate MVBs and show that the major substrates phosphorylated in vitro within MVBs which contain an active EGF-R kinase are the EGF-R itself and annexin I. Annexin I is associated with both plasma membrane and MVBs in a calcium-independent manner but can be phosphorylated in vitro only in MVBs. Phosphorylation of calcium-independent annexin I in isolated MVBs converts it to a form that requires calcium for membrane association. In cells with an active EGF-R kinase the amount of calcium-independent annexin I in MVBs is reduced, suggesting that a phosphorylation-induced conversion of the calcium independent to the calcium-dependent form also occurs in vivo. Our observations, together with the known properties of annexin I in mediating membrane fusion, suggest that inward vesiculation in MVBs is induced by the EGF-R and is mediated by phosphorylated annexin I.
Journal Articles
J Cell Biol (1992) 117 (1): 203–212.
Published: 01 April 1992
Abstract
This report describes analysis of factors which regulate the binding of EGF to EGF receptor, receptor internalization, and receptor recycling. Three different methods were used to inhibit high-affinity EGF binding as measured at equilibrium: treatment of cells with an active phorbol ester (PMA), binding of a mAb directed against the EGF receptor (mAb108), and truncation of most of the cytoplasmic domain of the receptor. These treatments reduced the rate at which low concentrations of EGF bound to cells, but did not affect the rate of EGF dissociation. We conclude that high-affinity EGF binding on living cells results from a difference in the apparent on rate of EGF binding. We then used these conditions and cell lines to test for the rate of EGF internalization at different concentrations of EGF. We demonstrate that internalization of the EGF receptor is stimulated roughly 50-fold at saturating concentrations of EGF, but is stimulated an additional two- to threefold at low concentrations (less than 1 nM). Four treatments reduce the rate of internalization of low concentrations of EGF to the rate seen at saturating EGF concentrations. Phorbol ester treatment and mAb108 binding to "wild type" receptor reduce this rate (and reduce high-affinity binding). Point mutation at Lys721 (kinase negative EGF receptor) and point mutation at Thr654 (removing a major site of protein kinase C phosphorylation) reduce the internalization rate, without affecting high-affinity binding. We suggest that while EGF stimulates endocytosis for all receptors, high-affinity receptors bind and are internalized more quickly than low-affinity receptors. Tyrosine kinase activity and the Thr654 region appear necessary for this response.
Journal Articles
Activation of insulin-epidermal growth factor (EGF) receptor chimerae regulates EGF receptor binding affinity.
J Cell Biol (1992) 116 (3): 627–633.
Published: 01 February 1992
Abstract
Cell surface tyrosine kinase receptors are subject to a rapid activation by their ligand, which is followed by secondary regulatory processes. The IHE2 cell line is a unique model system to study the regulation of EGF binding to EGF receptors after activation of the EGF receptor kinase. IHE2 cells express both a chimeric insulin-EGF receptor kinase (IER) and a kinase-deficient EGF receptor (HER K721A). We have previously reported that IER is an insulin-responsive EGF receptor tyrosine kinase that activates one or several serine/threonine kinases, which in turn phosphorylate(s) the unoccupied HER K721A. In this article we show that insulin through IER activation induces a decrease in 125I-EGF binding to IHE2 cells. Scatchard analysis indicates that, as for TPA, the effect of insulin can be accounted for by a loss of the high affinity binding of EGF to HER K721A. Since this receptor transmodulation persists in protein kinase C downregulated IHE2 cells, it is likely to be due to a mechanism independent of protein kinase C activation. Using an in vitro system of 125I-EGF binding to transmodulated IHE2 membranes, we illustrate that the inhibition of EGF binding induced by IER activation is related to the phosphorylation state of HER K721A. Further, studies with phosphatase 2A, or at a temperature (4 degrees C) where only IER is functional, strongly suggest that the loss of high affinity EGF binding is related to the serine/threonine phosphorylation of HER K721A after IER activation. Our results provide evidence for a "homologous desensitization" of EGF receptor binding after activation of the EGF receptor kinase of the IER receptor.
Journal Articles
Separate endocytic pathways of kinase-defective and -active EGF receptor mutants expressed in same cells.
J Cell Biol (1990) 110 (5): 1541–1548.
Published: 01 May 1990
Abstract
Ligand binding to the membrane receptor for EGF induces its clustering and internalization. Both receptor and ligand are then degraded by lysosomal enzymes. A kinase defective point mutant (K721A) of EGF receptor undergoes internalization similarly to the wild-type receptor. However, while internalized EGF molecules bound to either the wild-type or mutant receptors are degraded, the K721A mutant receptor molecules recycle to the cell surface for reutilization. To investigate the mechanism of receptor trafficking, we have established transfected NIH-3T3 cells coexpressing the kinase-negative mutant (K721A) together with a mutant EGF receptor (CD63) with active kinase. CD63 was chosen because it behaves like wild-type EGF receptor with respect to biological responsiveness and cellular routing but afforded immunological distinction between kinase active and inactive mutants. Although expressed in the same cells, the two receptor mutants followed their separate endocytic itineraries. Like wild-type receptor, the CD63 mutant was downregulated and degraded in response to EFG while the kinase-negative mutant K721A returned to the cell surface for reutilization. Intracellular trafficking of EGF receptor must be determined by a sorting mechanism that specifically recognizes EGF receptor molecules according to their intrinsic kinase activity.
Journal Articles
High-affinity epidermal growth factor binding is specifically reduced by a monoclonal antibody, and appears necessary for early responses.
J Cell Biol (1990) 110 (2): 491–502.
Published: 01 February 1990
Abstract
We have tested the effects of an mAb directed against the protein core of the extracellular domain of the human EGF receptor (mAb108), on the binding of EGF, and on the early responses of cells to EGF presentation. We used NIH 3T3 cells devoid of murine EGF receptor, transfected with a cDNA encoding the full-length human EGF receptor gene, and fully responsive to EGF. The binding to saturation of mAb108 to the surface of these cells at 4 degrees C and at other temperatures specifically reduced high-affinity binding of EGF, but did not change the dissociation constant or the estimated number of binding sites for low-affinity binding of EGF. The kinetics of EGF binding to the transfected cells were measured to determine the effects of the mAb on the initial rate of EGF binding at 37 degrees C. Interestingly, high-affinity EGF receptor bound EGF with an intrinsic on-rate constant 40-fold higher (9.8 x 10(6) M-1.s-1) than did low-affinity receptor (2.5 x 10(5) M-1.s-1), whereas the off-rate constants, measured at 4 degrees C were similar. Cells treated with the mAb or with phorbol myristate acetate displayed single on-rate constants similar to that for the low-affinity receptors. At low doses of EGF ranging from 0.4 to 1.2 nM, pretreatment of cells with mAb108 inhibited by 50-100% all of the early responses tested, including stimulation of tyrosine-specific phosphorylation of the EGF receptor, turnover of phosphatidyl inositol, elevation of cytoplasmic pH, and release of Ca2+ from intracellular stores. At saturating doses of EGF (20 nM) the inhibition of these early responses by prebinding of mAb108 was overcome. On the basis of these results, we propose that the high-affinity EGF receptors are necessary for EGF receptor signal transduction.
Journal Articles
Characterization of internalization and endosome formation of epidermal growth factor in transfected NIH-3T3 cells by computerized image-intensified three-dimensional fluorescence microscopy.
J Cell Biol (1989) 109 (5): 2105–2115.
Published: 01 November 1989
Abstract
Computerized image-intensified fluorescence microscopy has been used to quantify routing and subcellular concentrations of rhodaminated EGF (Rh-EGF) during its receptor-mediated endocytosis in two transfected NIH-3T3 cell lines expressing 2 X 10(5) and 1.5 X 10(6) receptors per cell, respectively. A series of images were digitized by focusing at different depths through the volume of a single cell. The digitized pictures were corrected for fluorescence photobleaching, and removal of out-of-focus fluorescence contributions by deconvolution using the point spread function of the microscope optics (Agard, D. A., and J. W. Sedat. 1980. Proc. Soc. Photo-Opt. Instr. Eng. 264:110-117) allowed automatic computer analysis of the time dependence of endosomal vesicle size and fluorescence intensity in a live cell and also enabled the study of isolated vesicles. An increase in the amount of fluorescence bound to the cell surface, either by increasing the number of receptors expressed per cell or the concentration of Rh-EGF in the incubation drop, yielded an increase in the total fluorescence of internalized vesicles without an increase in their number and area. The linear relation between fluorescence intensity and area for vesicles at different times indicates that EGF concentration is conserved. This is compatible with fusion of small vesicles to form larger ones. However, as endocytosis proceeds, a twofold increase in the slope of the fluorescence vs. area plots is observed for larger vesicles, suggesting that active sorting causes the EGF to be concentrated. Alternatively, this factor could be produced by cumulative fluorescence contributions from stacked membranes. Since coated pits are internalized independent of their occupancy with EGF receptor, we propose that endocytosis does not involve a mechanism specifically recognizing occupied receptor but is rather triggered by a global intracellular event.
Journal Articles
Overexpression of epidermal growth factor receptor in NIH-3T3-transfected cells slows its lateral diffusion and rate of endocytosis.
J Cell Biol (1988) 106 (6): 1903–1909.
Published: 01 June 1988
Abstract
Interactions between membrane proteins are believed to be important for the induction of transmembrane signaling. Endocytosis is one of the responses which is regulated by both intracellular and extracellular signals. To study such interactions, we have measured the lateral mobility and rate of endocytosis of epidermal growth factor receptor in three transfected NIH-3T3 cell lines (HER84, HER22, and HER82) expressing 2 X 10(4), 2 X 10(5) and 1.5 X 10(6) EGF-receptors per cell, respectively. Using rhodamine-labeled EGF (Rh-EGF) and rhodamine-labeled monoclonal anti-EGF-receptor antibody (Rh-mAb-108), we measured twofold decreases in the lateral diffusion coefficients for each approximately 10-fold increase in EGF-receptor concentration. Since steric effects cannot account for such dependence, we propose that protein mobility within the membrane, which is determined by the rate of motion between immobile barriers, decreases due to aggregate formation. The rate of endocytosis also decreases twofold between the HER84 (2 X 10(4) receptors/cell) and HER22 (2 X 10(5) receptors/cell) cell lines, suggesting that it is diffusion limited. The comparable rates of endocytosis of the HER82 and HER22 cell lines suggest that at high receptor density endocytosis may be limited by the total number of sites for receptors in coated-pits and by their rate of recycling.
Journal Articles
J Cell Biol (1986) 103 (6): 2067–2072.
Published: 01 December 1986
Journal Articles
Large deletions in the cytoplasmic kinase domain of the epidermal growth factor receptor do not affect its laternal mobility.
J Cell Biol (1986) 103 (2): 327–331.
Published: 01 August 1986
Abstract
The lateral diffusion coefficients of various epidermal growth factor (EGF) receptor mutants with increasing deletions in their carboxy-terminal cytoplasmic domain were compared. A full size cDNA construct of human EGF receptor and different deletion constructs were expressed in monkey COS cells. The EGF receptor mutants expressed on the cell surface of the COS cells were labeled with rhodamine-EGF, and the lateral diffusion coefficients of the labeled receptors were determined by the fluorescence photo-bleaching recovery method. The lateral mobilities of three deletion mutants, including a mutant that has only nine amino acids in the cytoplasmic domain, are all similar (D approximately equal to 1.5 X 10(-10) cm2/s) to the lateral mobility of the "wild-type" receptor, which possess 542 cytoplasmic domain of EGF receptor, including its intrinsic protein kinase activity and phosphorylation state, are not required for the restriction of its lateral mobility.
Journal Articles
Localization of the epidermal growth factor (EGF) receptor within the endosome of EGF-stimulated epidermoid carcinoma (A431) cells.
J Cell Biol (1986) 102 (2): 500–509.
Published: 01 February 1986
Abstract
We have followed the internalization pathway of both epidermal growth factor (EGF) and its receptor in human epidermoid carcinoma (A431) cells. Using EGF conjugated with horseradish peroxidase and anti-receptor monoclonal antibodies (TL5 and EGFR1) coupled either directly or indirectly to colloidal gold we have identified an extensive elaboration of endosomal compartments, consisting of a peripheral branching network of tubular cisternae connected to vacuolar elements that contain small vesicles and a pericentriolar compartment consisting of a tubular cisternal network connected to multivesicular bodies. Immunocytochemistry on frozen thin sections using receptor-specific antibody-gold revealed that at 4 degrees C in the presence of EGF, receptors were mainly on the plasma membrane and, to a lesser extent, within some elements of both the peripheral and pericentriolar endosomal compartments. Upon warming to 37 degrees C there was an EGF-dependent redistribution of most binding sites, first to the peripheral endosome compartment and then to the pericentriolar compartment and lysosomes. Upon warming only to 20 degrees C the ligand-receptor complex accumulated in the pericentriolar compartment. Acid phosphatase cytochemistry identifies hydrolytic activity only within secondary lysosomes and trans cisternae of the Golgi stacks. Together these observations suggest that the prelysosomal endosome compartment extends to the pericentriolar complex and that the transfer of EGF receptor complexes to the acid phosphatase-positive lysosome involves a discontinuous, temperature-dependent step.
Journal Articles
Incorporation of fluorescent gangliosides into human fibroblasts: mobility, fate, and interaction with fibronectin.
J Cell Biol (1984) 99 (2): 699–704.
Published: 01 August 1984
Abstract
Rhodamine- and fluorescein-labeled gangliosides were used as probes to investigate the distribution, dynamics, and fate of plasma membrane-bound gangliosides on cultured human fibroblasts. When sparse cultures of fibroblasts were incubated with the fluorescent ganglioside derivatives, their surfaces became highly fluorescent. The fluorescent gangliosides were taken up by the cells in a time- and temperature-dependent manner and were not removed from the cell surface by trypsin or serum. Thus, the gangliosides appeared to be stably incorporated into the lipid bilayer of the plasma membrane. Fluorescent photobleaching recovery measurements showed that the inserted gangliosides were free to diffuse in the plane of the membrane with a high diffusion coefficient of approximately 10(-8) cm2/s. When the ganglioside-treated cells were washed and incubated in fresh medium, the surface gangliosides became internalized with time, and localized in the perinuclear region of the fibroblasts. In dense cultures of fibroblasts, a large fraction of the fluorescent gangliosides were organized in a fibrillar network and were immobile on the time scale of fluorescent photobleaching recovery measurements. Using antifibronectin antibodies and indirect immunofluorescence, these gangliosides were found to co-distribute with fibrillar fibronectin. Thus, exogenous gangliosides appear to be stably inserted into the lipid bilayer of the plasma membrane and to diffuse freely in its plane as well as form a less mobile state with the fibrillar networks of fibronectin associated with the cells.
Journal Articles
J Cell Biol (1984) 99 (2): 425–434.
Published: 01 August 1984
Abstract
Microtubule-associated proteins (MAPs) from calf brain were fluorescently labeled with 6-iodoacetamido fluorescein (I-AF). The modified MAPs (especially enriched for MAP2) were fully active in promoting tubulin polymerization in vitro and readily associated with cytoplasmic filaments when microinjected into living cultured cells. Double-labeling experiments indicated that the microinjected AF-MAPs were incorporated predominantly, if not exclusively, into cytoplasmic microtubules in untreated cells or paracrystals induced within vinblastine-treated cells. Similar results were obtained with different cell types (neuronal, epithelial, and fibroblastic) of diverse origin (man, mouse, chicken, and rat kangaroo). Mobility measurements of the microinjected AF-MAPs using the method of fluorescence-photobleaching recovery (FPR) revealed two populations of AF-MAPs with distinct dynamic properties: One fraction represents the soluble pool of MAPs and is mobile with a diffusion coefficient of D = 3 X 10(-9) cm2/s. The other fraction of MAPs is associated with the microtubules and is essentially immobile on the time scale of FPR experiments. However, it showed slow fluorescence recovery with an apparent half time of approximately 5 min. The slow recovery of fluorescence on defined photobleached microtubules occurred most probably by the incorporation of AF-MAPs from the soluble cytoplasmic pool into the bleached area. The bleached spot on defined microtubules remained essentially immobile during the slow recovery phase. These results suggest that MAPs can associate in vivo with microtubules of diverse cell types and that treadmilling of MAP2-containing microtubules in vivo, if it exists, is slower than 4 micron/h.
Journal Articles
Interaction between major histocompatibility complex antigens and epidermal growth factor receptors on human cells.
J Cell Biol (1984) 98 (2): 725–731.
Published: 01 February 1984
Abstract
It has been suggested that products of the major histocompatibility complex, the MHC, of vertebrates function in many processes of recognition and ligand binding at the cell surface. Here we show that binding of polyclonal and monoclonal antibodies against human MHC antigens, HLA, reduced the binding of epidermal growth factor (EGF) to its membrane receptors on A-431 tumor cells and on normal human fibroblasts. Binding of EGF at 37 degrees C similarly inhibited the binding of Fab fragments and intact Ig anti-HLA to human cells. The inhibitory effect of anti-HLA antibodies was rapid and dependent upon temperature and antibody concentration and valence. Fluorescence microscopy qualitatively confirmed the binding data and showed that MHC antigens and EGF-receptors do not co-cluster in the membrane.
Journal Articles
Restricted mobility of membrane constituents in cell-substrate focal contacts of chicken fibroblasts.
J Cell Biol (1982) 93 (2): 495–500.
Published: 01 May 1982
Abstract
We studied the lateral mobility of membrane components in cell-substrate focal contacts using the fluorescence photobleaching recovery method. The measurements were performed on isolated substrate-attached membranes of chicken gizzard fibroblasts. The diffusion coefficients of a fluorescent lipid probe and rhodamine-conjugated surface proteins within contact regions (identified by interference-reflection microscopy) were significantly lower than those measured in nonattached areas along the ventral membrane. Complete recovery of fluorescence after photobleaching of the lipid probe was measured both in focal contacts and in nonattached areas with lateral diffusion coefficient (D) of approximately 10(-8) cm2/s. This indicated that the lipid probe is free to diffuse from and into the contact regions. Rhodamine-labeled surface components (mostly proteins) exhibited almost complete recovery after bleaching (approximately 90%) in unattached regions of the ventral membrane with D congruent to 10(-9 cm2/s. The rhodamine-labeled proteins in focal contacts showed only partial recovery (approximately 50%), suggesting that large proportion of the membrane proteins in cell-substrate contacts are immobile (within the time scale of the experiments, D less than or equal to 5 x 10(-12) cm2/s. The implications of these findings on the molecular dynamics of cell contacts are discussed.
Journal Articles
A nonmitogenic analogue of epidermal growth factor induces early responses mediated by epidermal growth factor.
J Cell Biol (1982) 92 (3): 687–693.
Published: 01 March 1982
Abstract
Cyanogen bromide-cleaved epidermal growth factor (CNBr-EGF) binds to EGF receptors with reduced affinity compared to the native hormone but fails to induce DNA synthesis. However, at similar receptor occupancy, CNBr-EGF is as potent as EGF in activating early cell responses to the hormone. The phosphorylation of membrane proteins, the stimulation of Na+-K+-ATPase as reflected by the ouabain-sensitive uptake of 86Rb of fibroblasts, changes in the organization of microfilaments and in cell-morphology, and the activation of the enzyme ornithine-decarboxylase are all induced by CNBr-EGF as well as EGF Our results are consistent with the notion that EGF-induced phosphorylation could act as a "second messenger" for the action of various EGF-induced responses such as activation of Na+-K+-ATPase, changes in the cytoskeleton and cell morphology, and the activation of the enzyme ornithine decarboxylase. However, the stimulation of phosphorylation of membrane proteins and other early responses are either not required or necessary but insufficient for the induction of DNA synthesis. Suboptimal concentrations of EGF together with CNBr-EGF stimulate DNA synthesis in human fibroblasts. Other growth factors such as insulin, fibroblast growth factor, and prostaglandin F2 alpha, which potentiate the mitogenic response of EGF, do not effect the response to CNBr-EGF. This suggests that the restoration of the mitogenic properties of CNBr-EGF by suboptimal doses of EGF occurs at the level of EGF receptors or during their processing. | https://rup.silverchair.com/jcb/search-results?f_Authors=J+Schlessinger |
The adaptive immune system is involved in elimina-tion of pathogens in the late phase of infection and in the generation of immunological memory. It consists of B- andsystem can be divided into humoral and cell-mediated immunity (CMI) (Fig. 4 and Table 3). The humoral response results in antibody formation (but contains cell-mediated events, Fig. 4A,B); CMI results in the generation of cytotoxic cells (Fig. 4A,B). The actionof antibodies and T-cells is dependent on accessory factors, some of which are mentioned in Table 3. In general, after infection with a pathogen or a protective vaccine, both humoral and cellular responses are generated. This indicates that both are needed for efficient protection. The balance between humoral and cellular responses, however, can differ widely between pathogens and is dependent on how the pathogen is presented to the adaptive immune system by APCs. This may have consequences for the design of a particular vaccine (see section “Vaccine design in relation to the immune response”).
Antibodies are the typical representatives of humoral immunity. An antibody belongs to one of four different immunoglobulin classes (IgM, IgG, IgA, or IgE). Upon immunization, the B-cells expressing specific antibodies on their cell surface (representing a fifth immunoglobulin class, IgD) are activated. The surface-bound antibodies bind specific epitopes of the pathogen, and in close cooperation with T-helper cells (Th-cells), the B-cell becomes activated eventually resulting in massive clonal proliferation. The prolif-erated B-cells are called plasma cells and excrete large amounts of soluble antibodies (Fig. 4B). Antibodies are able to prevent infection or disease by several mechanisms:
1. Binding of antibody covers the antigen with Fc (constant fragment), the “rear-end” of immunoglo-bulins. Phagocytic cells, like macrophages express surface receptors for Fc. This allows targeting of the opsonized (antibody-coated) antigen to these cells, followed by enhanced phagocytosis.
2. Immune complexes (i.e., antibodies bound to target antigens) can activate complement, a system of proteins which then becomes cytolytic to bacteria, enveloped viruses or infected cells.
3. Phagocytic cells may express receptors for com-plement factors associated with immune com-plexes. Binding of these activated complement factors enhances phagocytosis.
4. Viruses can be neutralized by antibodies through binding at or near receptor binding sites on the virus surface. This may prevent binding to and entry into the host cell.
Antibodies are effective against certain but not all infectious microorganisms; they may have limited value when CMI is the major protective mechanism. Of the cell types that are known to exhibit cytotoxicity, two are antigen-sensitized. Because of their specificity, they are of special importance with respect to vaccine design:
1. Cytotoxic T-lymphocytes (CTLs) react with target cells and kill them by release of cytolytic proteins like perforin. Target cells express non-self anti-gens like viral proteins or tumor antigens, by which they are identified. CTL responses, as antibody responses, are highly specific.
2. T-cells involved in delayed type hypersensitivity (TDTH) are able to kill target cells as CTLs do, but also have helper (Th1-type, see below) functions that enable them to activate macrophages.
Other, less specific cells involved in cytotoxic immune responses are natural killer cells (NK-cells). They play a role in antibody-dependent cellular cytotoxicity. NK-cells recognize opsonized (antibody coated) cells with their Fc-receptors.
Besides plasma cells and cytotoxic cells, in many cases memory B- and T-cells develop. Memory B-cells do not produce soluble antibody, but on repeated antigen contact their response time to develop into antibody-excreting plasma cells is shorter compared to naı¨ve B-cells.
The occurrence of different types of immune response to vaccines is the result of differences in antigen processing of the vaccine by APCs and, as a result, in the activation of Th-cells (Figs. 3 and 4). Major histocompatibility complex (MHC) molecules play an important role in the presentation of processed antigens to T-cells. Cells expose either MHC class I or II molecules on their surface.
APCs carrying class II molecules process solu-ble, exogenous (extracellular) proteins or more com-plicated structures such as microorganisms (Fig. 4A). After their endocytosis, the proteins are subject to limited proteolysis before they return as peptides to the surface of the APC in combination with the class II molecules for presentation to a T-cell receptor (TCR) of CD4 positive Th-cells. The Th-cells provide type 2 help necessary for the effector function of B-cells. This type 2 help is characterized by the lymphokine pattern produced: interleukin-4 (IL-4), IL-5, IL-6, IL-10, and IL-13. These lymphokines trigger B-cells, which eventually results in the production of IgM and IgG antibodies Cells carrying MHC class I molecules process endogenous (intracellularly produced) antigens like viral and tumor antigens, and present them in combination with class I molecules on the cell surface (Fig. 4C). The class I-antigen combination on the APC is recognized by the TCR of CD8 positive CTLs. Th-cells provide help for the CTLs. For the induction of CMI (Fig. 4A, C), type 1 help is needed (production of IL-2 and IL-12, interferon-g, and tumor necrosis factor). Th-cells are CD4 positive, regardless whether they have Th1or Th2 functions. There is increasing evidence that the Th1/Th2 balance is an important immunological parameter since some diseases coincide with Th1 (autoimmunity) or Th2 (allergy) type responses.
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An antigen (from the Greek ἀντί anti '[da] against', and γεννάω gennaō 'create / give birth') is a structure to which antibodies and certain lymphocyte receptors can specifically bind (the latter can also cause antibodies against the Antigen are produced) whereby the reaction of an organism to this structure or this substance can change specifically.
By somatic gene rearrangement , lymphocytes can form receptors for almost all possible substances. These substances are called antigens. The corresponding receptors of the lymphocytes are called B-cell receptors or T-cell receptors , depending on the type of lymphocytes . Originally, however, the term was only applied to substances that, after being injected into a foreign organism, led to the formation of antibodies. The specific binding of antibodies and antigen receptors to antigens is an essential part of adaptive immunity against pathogens . Antigens as “infectious substances” can trigger an immune response and thus have an immunogenic effect, but not every antigen is also immunogenic (e.g. haptens are not immunogenic). The location of the antigen that is recognized by the corresponding antibody is called the epitope .
construction
Antigens are mostly proteins , but they can also be carbohydrates , lipids or other substances. They can either be recognized or bound by B-cell receptors, T-cell receptors or antibodies (produced by B cells).
Antigens that are recognized by B-cell receptors or antibodies are located on the surfaces of foreign bodies that have penetrated (e.g. on pollen grains , bacterial surfaces and in the feces of house dust mites ) or cells and have a three-dimensional structure there, which is specific to certain B-cell receptors or antibodies can be recognized. Antigens on cell surfaces are called surface antigens . These are used, among other things, to develop vaccines against pathogens or tumors or are examined before a blood transfusion or organ transplant in order to avoid an immune reaction against foreign blood groups .
Antigens, which are recognized by T-cell receptors, are denatured peptide sequences of approx. Ten amino acids , which are taken up by antigen-presenting cells (APC) and presented on the surface together with MHC molecules .
The body's own structures, including antibodies , can act as antigens if they are mistakenly viewed as foreign ( autoantibodies ). This triggers an autoimmune reaction, which in severe cases can lead to an autoimmune disease .
Certain low-molecular substances that cannot cause an antibody reaction on their own, but can only trigger an immune reaction by binding to a carrier protein, are called haptens . These haptens were important in studying the binding of antibodies to an antigen by serving as chemically defined and changeable test subjects. Accordingly, a (mostly higher molecular weight) substance that enables this reaction on its own is called a full antigen , and a hapten is called a half antigen .
Small molecules such as single carbohydrates, amino or fatty acids cannot cause an immune reaction.
Effect and function
The benefit of antigen recognition by lymphocytes lies in the organism's ability to recognize foreign substances against which it has no hereditary encoded receptors. Lymphocytes that bind to the body's own substances (autoantigens) die; lymphocytes that bind to foreign antigens are able to trigger an adaptive immune response.
T lymphocytes (T cells) only recognize antigens when they are presented on the surfaces of other cells. Antigen presenting cells (APCs) are specialized cells of the immune system that present antigens to T cells. The so-called professional APCs include dendritic cells , macrophages and B cells. They take in substances via various mechanisms such as endocytosis , process them and couple them to MHC molecules. These are then presented on the plasma membrane. A T cell with a suitable T cell receptor (TCR) can then recognize the antigen as foreign and is activated if further costimulative signals are present.
B lymphocytes (B cells), which have bound to an antigen with their B cell receptor (the membrane precursor of the antibody), are activated either directly (TI antigen) or with the help of a T helper cell, depending on the antigen. T helper cells that have bound to an antigen-MHC complex and have recognized the antigen as foreign secrete cytokines that stimulate B cells to produce antibodies. Depending on which cytokines are released in the environment, a class switch takes place in one of the classes (Ig G, Ig E, Ig A). Antibodies are secreted by the plasma cells (activated B cells) , bind specifically to the antigen, thus marking the intruder ( opsonization ) and thus leading to phagocytosis of the foreign body. This task is performed by macrophages, for example, which bind to the constant region of the antibodies with their Fc receptors. By recognizing exogenous antigens, intruders such as bacteria or viruses can be fought against without damaging the body's own cells.
The cells of a stranger are also recognized as foreign, because the structure of the glycoproteins on the cell surfaces is different in every person. Therefore, these human antigens have an adverse effect on the transfer of organic material from one human to another, e.g. B. in blood transfusion or organ transplantation . Here, blood group and tissue compatibility must be observed. The transfer of wrong blood groups leads to clumping of the blood; in the case of transplants, the transferred organ can be rejected or the recipient can be damaged by the transplanted organ ( graft-versus-host disease ).
Antigens that can cause allergies are called allergens . They create an excessive immune response to a harmless antigen.
See also
literature
- Wilhelm Seyffert: Textbook of Genetics. Spectrum Academic Publishing House, Heidelberg / Berlin 2003, ISBN 3-8274-1022-3 .
- Charles A. Janeway Jr. including: immunology. 5th edition. Spectrum Academic Publishing House, Heidelberg / Berlin 2002, ISBN 3-8274-1078-9 . | https://de.zxc.wiki/wiki/Antigen |
Fc Effector Activity Bioassays
Our ADCC and ADCP Reporter Bioassays are biologically relevant, MOA-based assays that can be used to measure the potency and stability of antibodies and other biologics that specifically bind and activate Fcγ receptors. The assays consist of Jurkat cells stably expressing the relevant Fcγ receptor variant and a luciferase gene regulated by the NFAT response element.
The bioassays overcome the limitations of more labor-intensive and variable primary cell assays. The workflow is simple, scalable, and provides a quantitative measure of ADCC and ADCP with low variability and high accuracy.
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Introduction to Fc Effector Activity
Fc receptors are proteins expressed on the surface of immune cells that contribute to the protective functions of the immune system. By binding antibodies attached to the surface of target cells, Fc receptors initiate cytotoxic or phagocytic effector cell activity.
Antibody-dependent cell-mediated cytotoxicity (ADCC) is an important mechanism of action of antibodies that target virus-infected or diseased (e.g., tumor) cells for destruction by components of the cell-mediated immune system. Fc receptor-mediated effects contribute to the efficacy and safety of a variety of therapeutic antibodies. Human FcγRIII is the predominant receptor involved in ADCC and exists as a high-affinity (FcγRIIIa-V158) or low-affinity (FcγRIIIa-F158) variant, depending on the amino acid at position 158.
Antibody-dependent cell mediated phagocytosis (ADCP) is another critical mechanism of action for internalization and degradation of target cells by effector cells. Although other Fcγ receptors contribute, FcγRIIa is believed to be the predominant Fcγ receptor involved in ADCP.
Assays that can simply and reproducibly assess ADCC or ADCP are crucial in developing biologic therapeutics that function via these distinct mechanisms of action. | https://www.promega.com/products/reporter-bioassays/fc-effector-activity-bioassays/ |
Statistics refers to the aggregates or averages that relate to certain inquiries or relationships. The meaning of statistics can be understood in two ways: in the plural sense and in the singular sense.
Meaning of Statistics
Statistics In the plural sense
In the plural sense, statistics refers to the systematic collection of numerical facts. It indicates information in terms of numbers or numerical data such as employment statistics and population statistics.
Aggregate of facts: Statistics is an aggregate of numerical facts and figures. A single value does not represent statistics. For example, “marks of student A is 40” is not statistics. It is simply information. However, “marks of students A, B, and C are 40, 45 and 42 respectively” can be termed as statistics.
Expressed numerically: Statistics expresses qualitative variables in numerical terms. For example, “poverty has declined” is not a statistical statement. However, poverty has declined by 2% during 1995-96” can be termed as a statistical statement.
Collected in a systematic manner: Statistical data is collected in a systematic and planned manner. Data collected without any order or system is unreliable.
Affected by a multitude of causes: Statistical data is affected by a multitude of causes. For example, the data on the demand for a commodity is affected by a number of factors such as price, incomes of consumers, tastes, and preferences.
Collected for a purpose: Statistical data is always collected with a purpose. Data collected without any purpose is useless. For example, for a study of crop production in the country, the region from where and the crops for which data needs to be collected must be pre-decided.
Must facilitate comparison: The collected data must be able to facilitate comparison on various grounds such as time and region.
Maintains a fair degree of accuracy in estimation: Often, estimations (approximations) are made in case of large and voluminous data. However, such estimations must have a fair degree of accuracy.
Statistics in the singular sense
In the singular sense, statistics refers to the science of studying statistical methods. It indicates the techniques or methods of collecting, organizing, presenting, analyzing, and interpreting data.
Collection of data: It is the first step in any research or study. Thus, utmost care must be taken during the collection of data. Data can be collected by the investigator herself or from reliable sources such as published and unpublished data.
Organizing of data: The collected data must be organized properly by editing, classifying, and tabulating the same.
Presentation of data: The organized data cannot be used for analysis unless it is presented in a proper and systematic manner. Data can be presented in the form of tables, graphs, charts, diagrams, etc.
Analysis of data: Various tools and methods can be used for data analysis. Examples include averages, dispersion, correlation, and regression.
Interpretation of data: The last step in any research or study is data interpretation. A study is complete only when proper and meaningful conclusions or inferences are drawn from the data.
Functions of Statistics
The following are some of the important functions of statistics.
Presents data in a simplified form: With the help of statistical tools, large and complex data can be presented in a simple and understandable form. For example, consider data on the incomes of various families in a region. In itself, it is difficult to understand and interpret, but it becomes comprehensible when presented in the form of averages or some such measure
Gives a definite form to the facts: Statistics allows the conclusions of research or study to be presented in numerical form. This gives the conclusions a definite quality.
Facilitates comparison: Data can be easily compared using statistical tools such as averages, percentages, and ratios. Comparison of data helps us in drawing important economic conclusions. For instance, a comparison of the average incomes in rural areas and in urban areas helps us in drawing conclusions relating to regional inequality in income.
Guides in the formulation of theories and policies: Policies on various economic matters such as wages and prices are formed on the basis of statistical data. Statistics forms the basis for the formulation and testing of theories. For example, policies for improvement in agricultural production can be formed with the help of statistical data relating to the production of various crops in different regions.
Helps in forecasting: Statistical techniques help in forecasting and predicting the future behavior of various variables such as market situations.
Scope of Statistics
Statistical tools and methods have wide applicability across various fields. The following are the broad areas where statistics is applied.
Statistics and business: Business firms use statistics to study market fluctuations and various other relationships such as those between the price of a product and the demand for the same. Statistical methods are used to carry out market surveys on various matters. Statistical tools like analysis and interpretation of data are used for managing a business on various grounds such as production, quality, and cost control.
Statistics and government: Statistics prove highly useful in the effective functioning of the state. Various policies and plans of the government are formed on the basis of statistical facts and figures. Plans and policies regarding matters such as poverty, unemployment, and population cannot be formed without the availability of suitable statistical data.
Statistics and natural sciences: Statistical techniques play a vital role in the study of natural sciences such as medicine, biology, and botany. For example, in medicine, the diagnosis of a disease depends on data such as pulse rate and blood pressure. Similarly, statistical tools are used to carry out research on the success or failure of a drug.
Statistics and research: Statistical data is a significant input to conduct various researches. Researchers undertake researches for studying different relationships between different variables; for example, price and demand, poverty and health, etc.
Statistics and other fields: Statistics is also applied in other fields such as banking, insurance, and trade. For example, the interest rate to be charged on loans is decided on the basis of a survey on the probability of repayment of loans.
Limitations of Statistics
Though widely used, statistics suffers from certain limitations. Some of these are given below.
Describes only quantitative aspects: Statistics studies only variables that can be expressed as numerical values. It fails to take into account qualitative variables such as beauty and loyalty.
Studies only aggregate: Statistics deals only with aggregates of quantitative variables. Individual values have no significance in statistics.
Results hold true only as averages: Statistical laws hold true only on an average basis or approximation. They are not exact. For example, if per capita income in India is Rs 33000, then it does not necessarily mean that each and every person in the country earns Rs 33000.
Can only be used by experts: Only a person having a comprehensive and sophisticated knowledge of statistics can handle statistical data efficiently. Such data cannot be properly interpreted by a layman.
Data can be misused and manipulated: Statistical data can be manipulated and misused as per the user’s discretion. Such manipulated data results in misleading conclusions.
Inapplicable to heterogeneous data: Statistical tools do not facilitate comparison in the case of heterogeneous data. Data has to be homogeneous in order to be compared. Despite the wide applicability of statistics, it should be noted that it is not a substitute for common sense. Numerical data should not be used without applying common sense. Statistical data should not be believed blindly as it can be misinterpreted or misused.
For instance, statistical data may be politically influenced or may involve personal bias. Moreover, statistical data and methods fail to reveal the errors committed by the investigator while surveying and collecting the data.
Interrelationship between Economics and Statistics
Assessing the performance of an economy: Statistics provides the basis for analyzing the performance of an economy and comparing it with other economies. For example, data on national income for different years can be used to assess the
economic performance of the concerned economy over a period of time. Similarly, variables such as savings, investments, the relative importance of different sectors to national income, and the contribution of each sector to national income can be assessed with the help of statistical data and facts.
Analyzing economic problems: The magnitude of economic problems such as unemployment, poverty, illiteracy, and population can be judged with the help of statistical data. It is only when the gravity of the problems is understood with the help of statistical data that suitable policies can be formulated to control and remove them.
Analyzing the relationship between economic variables: Relationship between two or more economic variables can be assessed with the help of statistical data. Such an assessment is helpful in establishing a cause and effect relationship and, thereby, in taking suitable corrective measures. For example, if with the help of statistical data it is established that a rise in prices aggravates poverty, appropriate measures can be taken to control rising prices.
The base for economic theories and models: No economic theory or model can be constructed without relevant statistical experiments. The various laws and theories of economics such as the law of demand and the law of supply are based on statistical data.
Formulation of policies: Statistics helps the government and the policymakers in formulating various policies for economic development. For example, if the government aims at encouraging the production level, then it formulates a policy based on the average production levels for the past few years. Similarly, policies on poverty and unemployment are based on relevant statistical data.
Facilitates research: Statistical data forms the base for research and studies. Various statistical tools and techniques are employed in research and studies such as analyzing the effect of one variable on another.
Forecasting: Economic forecasting such as price trends and market situations has statistics as the base. This helps in the formulation of future plans and policies.
Relation with the four basic aspects of economics: Statistics is closely related to the four basic aspects of economics namely, consumption, production, distribution, and exchange.
Also, Read
Methods of Credit Control
Quantitative measures of credit control are those which affect the overall supply of money in an economy. These measures do not restrict the flow of credit to some specific sectors of the economy.
Inflation
Inflation is a sustained increase in the aggregate price levels. It refers to a state of rising prices and not a state of high prices. The types of inflation observed in an economy depend on the rate of increase in the price levels
Law of Demand
The law of demand states that other things remaining constant, the quantity of a good demanded increases with a fall in the price and diminishes when the price increases. | https://homeoflearning.in/statistics/ |
This is a very useful course in Machine Learning that teaches us how to use the R based packages such as CARET for applying machine learning techniques. The course project helps understand how these techniques are applied in real world applications and develop useful insights.
This is a very useful course in the Data Science Specialization that teaches us how to present the results of our data analysis using Shiny, Slidify and other R based data presentation tools. It also introduces open source charting APIs that we could use in our data analysis applications.
This is a very useful course in Data Analysis wherein we learn to explore the data sets and explore relationships between the variables for further analysis. It acts as a foundation for developing further models based on regression analysis or machine learning.
This course on Regression Models helps develop statistical models for analyzing data sets. These regression models help explore the relationships between the variables and build the first analytic models before any machine learning techniques are applied. The models covered are very useful for scientific research.
This is a very useful course in Data Science where in we learn to use R tools for getting data from various sources, cleaning the data and staging it for further analysis. The techniques are important to learn for subsequent courses in this specialization.
This is the first course in the Data Science Specialization series by Johns Hopkins University taught on Coursera. It introduces all the tools necessary for subsequent courses on data science and gives a driving motivation for the specialization.
This was a very useful course in Statistical Inference where in all the fundamentals are taught in a very clear manner, setting the stage for the subsequent course on regression models. The course is taught with examples on use of Statistical Inference in biostatistics and these examples are very helpful in understanding the concepts.
I found the exploratory techniques described in this course to be useful. The course content was well explained and I found the notes to be useful in completing the assignments.
I found the learning curve on this course to be very steep. I had to struggle a bit on the project but the discussion forums and a little online search was able to help me get to the right answers. I find the skills learned to be very useful in the subsequent courses on exploratory data analysis, statistical inference and regression models. If you are confident using plyr and dplyr libraries, it gives you more time to focus on the important parts of the code during analysis. | https://www.coursetalk.com/accounts/profile/nirav2 |
Abstract : — This paper presents a statistical approach to identify explanatory variables linearly related to e-commerce sales. The proposed methodology allows specifying a regression model in order to quantify the relevance between openly available data (economic and demographic) and national e-commerce sales. The proposed methodology consists in collecting data, preselecting input variables, performing regressions for choosing variables and models, testing and validating. The usefulness of the proposed approach is twofold: on the one hand, it allows identifying the variables that influence e-commerce sales with an accessible approach. And on the other hand, it can be used to model future sales from the input variables. Results show that e-commerce is linearly dependent on 11 economic and demographic indicators. | https://hal.archives-ouvertes.fr/hal-01790991 |
Proper data analysis techniques are required to obtain relevant and significant results from any statistical or any ‘natural’ experiment. To effectively transform data into information, one needs three elements to come together, namely Data, Analysis, and Results Presentation. A good combination of the three would naturally include a holistic explanation of the data collection method and its associated advantages and disadvantages, the methodology used for the analysis of the data, and the ideas that come out of the results to the person who will use the information that the data, its analysis and its interpretation yield.
Raw data is data that has been collected from a data source that has not been subject to processing or manipulation. Raw data may include anomalies, oddities or inaccurate/wrong inputs, and must therefore be checked before analysis. The quality of the data can be checked through checks constructed in accordance with the nature of the data, visual inspections, Box-Whisker Plots, descriptive statistics (mean, median, standard deviation), normality (skewness, kurtosis), correlation, Cook’s distance statistics, leverage values and sample size. Variables may sometimes need some form of transformation before being subjected to analysis. However, it is always important to make sure that the transformation being effected is not one that will yield the results that the analyst would like to see, as such results would be spurious. There are several data analysis techniques that can be applied to different business, social, economic and scientific domains.
Data analysis is often dependent on data capture equipment, data storage through databases and data warehouses, and statistical analysis and Business Intelligence programs such as Oracle, MS SQL, MS Excel, SPSS, Stata and EViews. These processes, backed up by programs to automate them, allow the statistician to mine the data, to prepare it in the required form, and to subsequently analyse it to draw inferences and produce the required results. Through these results, the researcher can accept or reject an initial hypothesis on the basis of the collected data and statistical tests run on it. When carrying out data analysis on a sample that has been drawn out of a population, there is always a degree of error that the statistical analyst has to live with. The Statistical Significance of the result will determine whether the observed results have occurred due to mere chance or to a resilient statistical relationship, and the initial hypothesis will, on that showing either be rejected or accepted. Other statistical tests can be carried out depending on the type of data at hand, its characteristics and the initial hypothesis to be tested.
Once the data is analysed, useful information that supports decision-making and suggests viable issue resolutions is obtained. Clear and accurate reporting from the data analysis process is a vital step in deducing these results. It is also paramount to ask the right questions to be able to come up with the relevant answers. After observing the data, the researcher must report the statistical findings in a comprehensive manner using presentable formats that allow the reader to understand how the indicators work, their caveats, their relevance to the situation being analysed and their implications.
The team at Equinox Advisory can apply their combined statistical and economic skills to serve your needs by:
- Collecting primary data, that is, data which is not already available;
- Applying and assessing currently-available economic data to the specific circumstance(s) at hand through the understanding of its applications and limitations;
- Identifying specific changes and trends in the data and ascertaining their significance;
- Measuring relationships and associations between two or more variables;
- Applying data mining techniques to analytically process large amounts of data while detecting patterns and relationships in the data through the use of algorithms;
- Using data analysis and statistics software to interpret economic data including cross-sectional, time-series and panel-data; and
- Interpreting different data sets using assumptions and rationales that are coherent with economic theory. | https://equinoxadvisory.com/services/quantitative-economics/data-analysis-reporting/ |
Worsening of model performance caused by changes in data and relationships between input and output variables is referred to as Model Drift. Businesses should track and manage their model performance over time in order to detect and minimise drift, which can have a negative impact otherwise.
Model drift can be classified into two broad categories:
- Concept Drift – The properties of the dependent (target) variable changes thus, changing the relationship between the independent and dependent variables.
- Data Drift – The statistical properties of the independent variable(s) change(s).
More precisely, Machine Learning models deployed in the industry are often trained on one dataset referred to as ‘Development/Training Dataset’ and these models are then used to predict another dataset called the ‘Production/Review Dataset’. Model drift indicates that the model does not perform robustly on the Review dataset.
Difference Between Data Drift and Model Drift in Practice
Data drift deals with the change in distribution of the datasets, particularly the independent variables(features) and does not take the model or the model’s performance into consideration. Concept drift deals with the distribution of target variables and/or predicted probabilities of the model.
Methods to Verify and Measure Data and Concept Drift
There are three main techniques to measure drift:
- Statistical: This approach can be used to detect/verify both Data and Concept Drift. It uses various statistical metrics on the datasets to conclude whether the distribution of the training data is different from the production data distribution.
- Model Based: This approach involves training a classification model to determine whether certain data points are similar to another set of data points and hence can be used for verifying Data Drift. If the model has a hard time differentiating between the data, then there isn’t any significant data drift. If the model is able to correctly separate the data groups, then there likely is some data drift.
- Adaptive Windowing (ADWIN): This approach to detect Concept Drift is used with streaming data, where there is a large amount of infinite data flowing in and it is infeasible to store it all.
Statistical Approach
Many of these approaches compare distributions. There are a number of different statistical distance measures that can help quantify the change between distributions. Different distance checks are useful in different situations. A comparison requires a reference distribution which is the fixed data distribution that we compare the production data distribution to. For example, this could be the first month of the training data, or the entire training dataset. It depends on the context and the timeframe in which you are trying to detect drift. But obviously, the reference distribution should contain enough samples to represent the training dataset.
Mean
One of the first and simplest measures we can look at is the average for our features. If the mean gradually shifts in a particular direction over the months, then there probably is data drift happening. Having said that, mean isn’t the best method to check for drift but is a good starting point.
Population Stability Index (PSI)
PSI is often used in the finance industry and is a metric to measure how much a variable has shifted in distribution between two samples or over time. As the name suggests it helps measure the population stability between two population samples. It is calculated by bucketing the two distributions and comparing the percentages of items in each of the buckets, resulting in a single number you can use to understand how different the populations are.
The ln(Actual%/Expected%) term implies that a large change in a bin that represents a small percentage of a distribution will have a larger impact on PSI than a large change in a bin with a large percentage of the distribution.
It should be noted that the population stability index simply indicates changes in the feature. However, this may or may not result in deterioration in performance. So if you do notice a performance degradation, you could use PSI to confirm that the population distributions have indeed changed.
Kullback-Leibler (KL) divergence
KL divergence measures the difference between two probability distributions and is also known as the relative entropy. KL divergence is useful if one distribution has a high variance to the other distribution.
KL divergence is also not symmetric. This means that unlike PSI, the results will vary if the reference and production(compared) distributions pair are switched. So KL(P || Q) != KL(Q || P). This makes it useful for applications involving Baye’s theorem or when you have a large number of training (reference) samples but only a small set of samples (resulting in more variance) in the comparison distribution.
A KL score can range from 0 to infinity, where a score of 0 means that the two distributions are identical. If the KL formulae are taken to log base 2, the result will be in bits, and if the natural log (base-e) is used, the result will be in “nats”.
Jensen-Shannon (JS) Divergence
The JS divergence is another way to quantify the difference between two probability distributions. It uses the KL divergence that we saw above to calculate a normalized score that is symmetrical. This makes JS divergence score more useful and easier to interpret as it provides scores between 0 (identical distributions) and 1 (maximally different distributions) when using log base 2.
With JS there are no divide-by-zero issues. Divide by zero issues come about when one distribution has values in regions the other does not.
Wasserstein distance metric
The Wasserstein distance, also known as the Earth Mover’s distance, is a measure of the distance between two probability distributions over a given region. The Wasserstein Distance is useful for statistics on non-overlapping numerical distribution moves and higher dimensional spaces, for example images.
Kolmogorov–Smirnov test (K–S test or KS test)
The KS test is is a nonparametric test of the equality of continuous/discontinuous, one-dimensional probability distributions that can be used to compare a sample with a reference probability distribution (one-sample K–S test), or to compare two samples (two-sample K–S test).
Model Based
An alternative to the statistical methods explored above is to build a classifier model to try and distinguish between the reference and compared distributions. We can do this using the following steps:
- Tag the data from the batch used to build the current production model as 0.
- Tag the batch of data that we have received since then as 1.
- Develop a model to discriminate between these two labels.
- Evaluate the results and adjust the model if necessary.
If the developed model can easily discriminate between the two sets of data, then a covariate shift has occurred and the model will need to be recalibrated. On the other hand, if the model struggles to discriminate between the two sets of data (it’s accuracy is around 0.5 which is as good as a random guess) then a significant data shift has not occurred and we can continue to use the model.
ADWIN Adaptive Sliding Window
As mentioned earlier, the above techniques aren’t very suitable when we have a stream of input data. In some scenarios, the data may drift so quickly that by the time we collect data and train a model, the trends would have changed and our model is out of date. But figuring out the best time frame to consider for training is not that straightforward either. This is where the Adaptive Sliding Window technique is helpful. It is adaptive to the changing data. For instance, if the change is taking place, the window size will shrink automatically, else if the data is stationary, the window size will grow to improve the accuracy.
These techniques can be used to detect data drift according to their suitability. But we want to avoid waiting until we notice significant performance degradation in our model to start investigating for data drift. That’s where having a model monitoring plan becomes very useful.
At Predactica, we offer a platform to monitor and manage your Machine Learning/AI models. We detect and verify Data Drift and Concept Drift in your model using metrics such as PSI, Kullback-Leibler Divergence and Jenson Shannon Divergence to help you ensure that the model runs smoothly and efficiently in production. | https://predactica.com/blog/validation-and-evaluation-of-model-drift/ |
Risk is a perennial problem in the financial market because, despite the best efforts of forecasting techniques, we cannot foresee the future with absolute certainty. Numerous quantitative measures of risk are used in the literature, such as Value at Risk (VaR) and Expected Shortfall (ES). These measurements, however, typicaly only account for static and frequency-based uncertainty, making it difficult for them to keep up with the financial markets' rapid changes. These limitations impede the continued development of a universal, practical framework for managing risks in financial time series analysis in the big data era. Bayesian non-parametric (BNP) models promise to loosen the assumption (such as normality, linearity, stationarity) without sacrificing interpretability and increasing computational cost in order to solve these limitations as a probabilistic strategy.
The project's objectives are to theoretically and empirically examine financial market risk and further explore the idea of applying BNP to this risk. Risk measurement, risk modelling and forecasting, and the evaluation of risk models are some of the subjects that make up our project.
Knowing how to quantify risk is important before making any predictions about market risk. In order to achieve this, we explicitly investigated the criteria that a risk measurement must satisfy, namely Translation Invariance, Subadditivity, Positive Homogeneity, and Monotonicity, before theoretically examining the statistic and stochastic representation for the risk measurement. Even though VaR was the major emphasis of this seed fund project, once stochastic analysis tools are introduced, we can take a dynamic representation of risk into consideration.
We thoroughly investigated the various approaches for risk prediction both theoretically and empirically, in contrast to previous studies that either only compared the data-driven methods, such as neural networks and quantile regression, or only investigated the traditional model-driven approaches for market risk prediction, such as GARCH, EGARCH, and CAViaR. Additionally, a clear road map for the relationships between various models and how they are upgraded and evolved was extensively illustrated with a discussion of their benefits and cons.
We chose some of the most representative and State-Of-The-Art models, such as GARCH, EGARCH, LSTM, and so on, to run our experiment on the appropriate configuration of the datasets in order to provide an adequate comparison between various methodologies. In addition to predicting VaR for the test dataset, various assessment techniques (such as the Kupiec-test and exception rate) have also been used to confirm the statistical superiority of one model over others. Our tested model spans a wide range, from the ARCH family to cutting-edge neural network models.
Furthermore, we created a helpful framework (a Python package) that enables academics to contrast various market risk models, including both traditional and data-driven risk models. In order for us to create a new BNP framework to control financial market risk, this effort is crucial.
Overall, our initial research on financial market risk has prepared us to consider the next stage, which involves using BNP tools to control financial market risk. During the project's duration, I visited my collaborator, Dr Bo Wang, at the University of Leicester, and I presented a research seminar on financial market risk from a Bayesian non-parametric perspective. We settled on a topic, 'functional data analysis for financial market risk modelling with Gaussian process quantile regression', after a lengthy discussion. After carefully developing the concept, Bo and I will submit an EPSRC proposal jointly. | https://www.business-school.ed.ac.uk/index.php/about/news/financial-market-risk-from-a-bayesian-non-parametric-perspective |
SUMMARY:
- Expertise in analyzing large - scale national and commercial dataset to identify social economic as well as demographic trends within different population groups/segments for social and policy decision making
- Expertise in quantitative research methods, survey design, data collection and subsequent analysis via statistical models such as Multivariate Regression, Logistic Regression, Hierarchical Linear Modeling, Fixed-Effects Model, Propensity Score Matching, Time-varying Discrete Mode ling
- Easy going, self-driven, a team player and a good communicator
TECHNICAL SKILLS:
Programming: STATA, SA, SPSS, R, ArcGIS
Software: Word/Excel/Access/Powerpoint
WORK & RESEARCH EXPERIENCE:Statistical Consultant
Confidential
Responsibilities:
- Conducted a literature review and examined the contextual effects of schools and immigration on the formation of interracial romantic relationships, as well as the consequences of interracial relationships on teen sexuality and contraception.
- Applied General Linear and Mixed models, multilevel multinomial regression, and multilevel logistic regression to analyze and quantify the impact of individual, family, and social contextual factors on adolescents’ interracial romantic behavior and sexual behavior.
Summer Internship
Confidential, New York
Responsibilities:
- Identify specific social and demographic factors that influence world-wide contraceptive use based on country-level survey data.
- Prepared data on contraceptive use and fertility rates pattern among different age groups and countries to be used for Millennium Development Goals (MDG).
Statistical Consultant
Confidential, Ann Arbor
Responsibilities:
- Provided technical support on using STATA, SPSS, R, and SAS to over 200 world-wide participants during the summer program focusing on advanced research design, statistics, data analysis, and social methodology.
- Assisted participants on applying, understanding, and interpreting results from statistical models used for social science and public policy research.
Research Assistant
Confidential, Ann Arbor
Responsibilities:
- Participated in survey design and questionnaire development; In charge of subsequent data quality control and management
- Analyzed data using advanced statistical models to evaluate impacts of forced migration policy on people’s future economic well-being in China.
- Co-authored a research paper published in Social Science Research.
- Collaborated with global research team on project that measured people’s understanding and acceptance of developmental ideas and theories.
- Worked on survey design, questionnaire development; Performed preliminary data analysis of pre-test dataset.
- Co-authored a book chapter on Survey Methods.
Research Assistant
Confidential
Responsibilities:
- Applied statistical analysis to large-scale national datasets to identify social-economic as well as demographic trends among different age groups within the entire Confidential .
- Analyzed Confidential ’s proprietary datasets and identified major demographic characteristics that drive the observed behavior of car-buying consumers;
- Forecasted impacts on Confidential ’s long term industry and segment outlook based on identified national trends and Confidential -specific consumer behavior characteristics. | https://www.hireitpeople.com/resume-database/79-other-resumes/232099-statistical-consultant-resume-4 |
a predictive model to an observed data set of values of the response and explanatory variables.
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Fitting a linear model to a given data set usually requires estimating the regression coefficients such that the error term is minimized.
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For standard least squares estimation methods, the design matrix X must have full column rank p; otherwise perfect multicollinearity exists in the predictor variables, meaning
a linear relationship exists between two or more predictor variables.
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It is also possible in some cases to fix the problem by applying a transformation to the response variable (e.g., fitting the logarithm of the response variable using a linear
regression model, which implies that the response variable itself has a log-normal distribution rather than a normal distribution).
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In the more general multivariate linear regression, there is one equation of the above form for each of m > 1 dependent variables that share the same set of explanatory variables
and hence are estimated simultaneously with each other: for all observations indexed as i = 1, … , n and for all dependent variables indexed as j = 1, … , m. Nearly all real-world regression models involve multiple predictors, and basic
descriptions of linear regression are often phrased in terms of the multiple regression model.
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This model is non-linear in the time variable, but it is linear in the parameters β1 and β2; if we take regressors xi = (xi1, xi2) = (ti, ti2), the model takes on the standard
form Assumptions See also: Ordinary least squares § Assumptions Standard linear regression models with standard estimation techniques make a number of assumptions about the predictor variables, the response variables and their relationship.
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Applications of the group effects include (1) estimation and inference for meaningful group effects on the response variable, (2) testing for “group significance” of the variables
via testing versus , and (3) characterizing the region of the predictor variable space over which predictions by the least squares estimated model are accurate.
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A simple way to identify these meaningful group effects is to use an all positive correlations (APC) arrangement of the strongly correlated variables under which pairwise
correlations among these variables are all positive, and standardize all predictor variables in the model so that they all have mean zero and length one.
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For example, weighted least squares is a method for estimating linear regression models when the response variables may have different error variances, possibly with correlated
errors.
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prices or populations) that vary over a large scale—which are better described using a skewed distribution such as the log-normal distribution or Poisson distribution (although
GLMs are not used for log-normal data, instead the response variable is simply transformed using the logarithm function); • when modeling categorical data, such as the choice of a given candidate in an election (which is better described using
a Bernoulli distribution/binomial distribution for binary choices, or a categorical distribution/multinomial distribution for multi-way choices), where there are a fixed number of choices that cannot be meaningfully ordered; • when modeling
ordinal data, e.g.
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Many statistical inference procedures for linear models require an intercept to be present, so it is often included even if theoretical considerations suggest that its value
should be zero.
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In general, for a group of strongly correlated predictor variables in an APC arrangement in the standardized model, group effects whose weight vectors are at or near the centre
of the simplex ( ) are meaningful and can be accurately estimated by their minimum-variance unbiased linear estimators.
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• If the goal is to explain variation in the response variable that can be attributed to variation in the explanatory variables, linear regression analysis can be applied
to quantify the strength of the relationship between the response and the explanatory variables, and in particular to determine whether some explanatory variables may have no linear relationship with the response at all, or to identify which
subsets of explanatory variables may contain redundant information about the response.
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Others • In Dempster–Shafer theory, or a linear belief function in particular, a linear regression model may be represented as a partially swept matrix, which can be
combined with similar matrices representing observations and other assumed normal distributions and state equations.
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Group effects provide a means to study the collective impact of strongly correlated predictor variables in linear regression models.
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The decision as to which variable in a data set is modeled as the dependent variable and which are modeled as the independent variables may be based on a presumption that
the value of one of the variables is caused by, or directly influenced by the other variables.
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Multiple linear regression is a generalization of simple linear regression to the case of more than one independent variable, and a special case of general linear models,
restricted to one dependent variable.
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However, it has been argued that in many cases multiple regression analysis fails to clarify the relationships between the predictor variables and the response variable when
the predictors are correlated with each other and are not assigned following a study design.
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The link function is often related to the distribution of the response, and in particular it typically has the effect of transforming between the range of the linear predictor
and the range of the response variable.
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The model remains linear as long as it is linear in the parameter vector β. o The values xij may be viewed as either observed values of random variables Xj or as fixed values
chosen prior to observing the dependent variable.
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In linear regression, the relationships are modeled using linear predictor functions whose unknown model parameters are estimated from the data.
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In statistics, linear regression is a linear approach for modelling the relationship between a scalar response and one or more explanatory variables (also known as dependent
and independent variables).
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Some methods such as generalized least squares are capable of handling correlated errors, although they typically require significantly more data unless some sort of regularization
is used to bias the model towards assuming uncorrelated errors.
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Like all forms of regression analysis, linear regression focuses on the conditional probability distribution of the response given the values of the predictors, rather than
on the joint probability distribution of all of these variables, which is the domain of multivariate analysis.
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Generalized linear models allow for an arbitrary link function, g, that relates the mean of the response variable(s) to the predictors: .
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Effects with weight vectors far away from the centre are not meaningful as such weight vectors represent simultaneous changes of the variables that violate the strong positive
correlations of the standardized variables in an APC arrangement.
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Methods for fitting linear models with multicollinearity have been developed, some of which require additional assumptions such as “effect sparsity”—that a large
fraction of the effects are exactly zero.
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It has an interpretation as the expected change in the response variable when increases by one unit with other predictor variables held constant.
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To check for violations of the assumptions of linearity, constant variance, and independence of errors within a linear regression model, the residuals are typically plotted
against the predicted values (or each of the individual predictors).
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If the experimenter directly sets the values of the predictor variables according to a study design, the comparisons of interest may literally correspond to comparisons among
units whose predictor variables have been “held fixed” by the experimenter.
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The basic model for multiple linear regression is for each observation i = 1, … , n. In the formula above we consider n observations of one dependent variable and p independent
variables.
-
Single index models[clarification needed] allow some degree of nonlinearity in the relationship between x and y, while preserving the central role of the linear predictor
β′x as in the classical linear regression model.
-
This can be caused by accidentally duplicating a variable in the data, using a linear transformation of a variable along with the original (e.g., the same temperature measurements
expressed in Fahrenheit and Celsius), or including a linear combination of multiple variables in the model, such as their mean.
-
Most commonly, the conditional mean of the response given the values of the explanatory variables (or predictors) is assumed to be an affine function of those values;
less commonly, the conditional median or some other quantile is used.
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For a group of predictor variables, say, , a group effect is defined as a linear combination of their parameters where is a weight vector satisfying .
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Group effects In a multiple linear regression model parameter of predictor variable represents the individual effect of .
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In this case, we “hold a variable fixed” by restricting our attention to the subsets of the data that happen to have a common value for the given predictor variable.
-
After developing such a model, if additional values of the explanatory variables are collected without an accompanying response value, the fitted model can be used to make
a prediction of the response.
-
The case of one explanatory variable is called simple linear regression; for more than one, the process is called multiple linear regression.
-
Linear regression models are often fitted using the least squares approach, but they may also be fitted in other ways, such as by minimizing the “lack of fit” in some other
norm (as with least absolute deviations regression), or by minimizing a penalized version of the least squares cost function as in ridge regression (L2-norm penalty) and lasso (L1-norm penalty).
-
The following are the major assumptions made by standard linear regression models with standard estimation techniques (e.g.
-
Beyond these assumptions, several other statistical properties of the data strongly influence the performance of different estimation methods: • The statistical relationship
between the error terms and the regressors plays an important role in determining whether an estimation procedure has desirable sampling properties such as being unbiased and consistent.
-
(In fact, as this shows, in many cases—often the same cases where the assumption of normally distributed errors fails—the variance or standard deviation should be predicted
to be proportional to the mean, rather than constant.)
-
This essentially means that the predictor variables x can be treated as fixed values, rather than random variables.
-
Although polynomial regression fits a nonlinear model to the data, as a statistical estimation problem it is linear, in the sense that the regression function E(y | x) is
linear in the unknown parameters that are estimated from the data.
-
The relationship between the error term and the regressors, for example their correlation, is a crucial consideration in formulating a linear regression model, as it will
determine the appropriate estimation method.
-
Interpretation The data sets in the Anscombe’s quartet are designed to have approximately the same linear regression line (as well as nearly identical means, standard
deviations, and correlations) but are graphically very different.
-
Individual effects of such variables are not well-defined as their parameters do not have good interpretations.
-
Thus, although the terms “least squares” and “linear model” are closely linked, they are not synonymous.
-
Thus meaningful group effects of the original variables can be found through meaningful group effects of the standardized variables.
-
-
A group effect of the original variables can be expressed as a constant times a group effect of the standardized variables .
-
Bayesian linear regression techniques can also be used when the variance is assumed to be a function of the mean.
-
The predictor variables themselves can be arbitrarily transformed, and in fact multiple copies of the same underlying predictor variable can be added, each one transformed
differently.
-
Errors-in-variables Errors-in-variables models (or “measurement error models”) extend the traditional linear regression model to allow the predictor variables X to be
observed with error.
-
Generally these extensions make the estimation procedure more complex and time-consuming, and may also require more data in order to produce an equally precise model.
-
Bayesian linear regression can also be used, which by its nature is more or less immune to the problem of overfitting.
-
Furthermore, when the sample size is not large, none of their parameters can be accurately estimated by the least squares regression due to the multicollinearity problem.
-
Although this assumption is not realistic in many settings, dropping it leads to significantly more difficult errors-in-variables models.
-
Under certain conditions, simply applying OLS to data from a single-index model will consistently estimate β up to a proportionality constant.
-
This is because models which depend linearly on their unknown parameters are easier to fit than models which are non-linearly related to their parameters and because the
statistical properties of the resulting estimators are easier to determine.
-
Alternatively, there may be an operational reason to model one of the variables in terms of the others, in which case there need be no presumption of causality.
-
Both interpretations may be appropriate in different cases, and they generally lead to the same estimation procedures; however different approaches to asymptotic analysis
are used in these two situations.
-
With this much flexibility, models such as polynomial regression often have “too much power”, in that they tend to overfit the data.
-
Simple and multiple linear regression Example of simple linear regression, which has one independent variable The very simplest case of a single scalar predictor variable
x and a single scalar response variable y is known as simple linear regression.
-
A fitted linear regression model can be used to identify the relationship between a single predictor variable xj and the response variable y when all the other predictor variables
in the model are “held fixed”.
-
When is strongly correlated with other predictor variables, it is improbable that can increase by one unit with other variables held constant.
-
The notion of a “unique effect” is appealing when studying a complex system where multiple interrelated components influence the response variable.
-
• The arrangement, or probability distribution of the predictor variables x has a major influence on the precision of estimates of β.
-
With strong positive correlations and in standardized units, variables in the group are approximately equal, so they are likely to increase at the same time and in similar
amount.
-
The presence of heteroscedasticity will result in an overall “average” estimate of variance being used instead of one that takes into account the true variance structure.
Works Cited
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Erlbaum Associates
3. Charles Darwin. The Variation of Animals and Plants under Domestication. (1868) (Chapter XIII describes what was known about reversion in Galton’s time. Darwin uses the term “reversion”.)
4. Draper, N.R.; Smith, H. (1998).
Applied Regression Analysis (3rd ed.). John Wiley. ISBN 978-0-471-17082-2.
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6. Robert S. | https://3dresearchspecs.com/en/wiki/linear-regression/ |
The TAYLORFIT program contains an algorithm which can identify complex relationships among data, including nonlinearity and interactions, and present the result as a mathematical expression which is much easier to use and understand than competing methods, but equally or more powerful in its capabilities. It can be used for multivariate correlation analysis, time-series analysis or to generate discriminant functions.
The method is called Multivariate Polynomial Regression, or MPR. It produces a polynomial describing the relationship between any set of inputs and corresponding outputs. It can replace techniques such as multilinear regression and ARMA (Box-Jenkins) models, and can produce far superior results. It can also be used in applications to which artificial neural networks have been applied. However, MPR is easier to use and understand and avoids overfitting errors. MPR is essentially a multiple regression model with polynomial and cross-product (interaction) terms. For example, if Y is a function of Q, R, and S, terms can be included such as QR2S or Q3S. MPR models can be fitted using conventional multiple regression software, and only terms which are statistically significant are retained in the model. MPR models are applicable to low-to-moderate dimensionality problems as are encountered in economics.
MPR models can describe logical relationships between a dependent variable and multiple independent variables which linear ARMA models are incapable of capturing. Therefore MPR models can produce better fits and less bias in predictions.
If the number of independent variables is not too great, MPR models compare favorably in performance to artificial neural network (ANN) models. MPR models can provide a better fit with fewer coefficients. This reduces overfitting or "memorizing" of data. The fitting procedure converges absolutely and does not require a priori selection of model structure. The procedure gives a simple explicit equation for prediction or analysis, and standard statistical tests can be applied to all coefficients and forecast predictions.
We have shown how time-series data can be modeled by multivariable polynomials. MPR is applied to the Lorenz equations, a challenging nonlinear system with chaotic dynamics. MPR accurately captures the dynamic behavior.
Other work describes the use of MPR for multivariable analysis, similar to multilinear regression. The application involves determining the relationship between the profitability of a series of stores and various predictor variables, such as market share, age of store, etc. | https://personal.stevens.edu/~dvaccari/pf.html |
In recent years there has been growing interest in discriminative parameter training techniques, resulting from notable improvements in speech recognition performance on tasks ranging in size from digit recognition to Switchboard. Typified by Maximum Mutual Information (MMI) or Minimum Classification Error (MCE) training, these methods assume a fixed statistical modeling structure, and then optimize only the associated numerical parameters (such as means, variances, and transition matrices). Such is also the state of typical structure learning and model selection procedures in statistics, where the goal is to determine the structure (edges and nodes) of a graphical model (and thereby the set of conditional independence statements) that best describes the data.
In this project, we explore the novel and significantly different methodology of discriminative structure learning. Here, the fundamental dependency relationships between random variables in a probabilistic model are learned in a discriminative fashion, and are learned separately and in isolation from the numerical parameters. The resulting independence properties of the model might in fact be wrong with respect to the true model, but are made only for the sake of optimizing classification performance. In order to apply the principles of structural discriminability, we adopt the framework of graphical models, which allows an arbitrary set of random variables and their conditional independence relationships to be modeled at each time frame.
We also, in this project, present results using a new graphical modeling toolkit (GMTK). Using GMTK and discriminative structure learning heuristics, the results presented herein indicate that significant gains result from discriminative structural analysis of both conventional MFCC and novel AM-FM features on the Aurora continuous digits task. Lastly, we also present results using GMTK on several other tasks, such as on an IBM audio-video corpus, preliminary results on the SPINE-1 data set using hidden noise variables, on hidden articulatory modeling using GMTK, and on the use of interpolated language models represented by graphs within GMTK. | https://www.clsp.jhu.edu/workshops/01-workshop/discriminatively-structured-graphical-models-for-speech-recognition/ |
In this study, new linear programming (LP) approaches are developed as nonparametric procedures for multiple-class discrimination and classification. Specifically, a LP model minimizing the sum of the classification errors, or the-norm, and a LP model minimizing the maximum of the classification errors, or the -norm, are formulated. These new models are more straightforward and simpler than any of the previous LP formulations for multiple-class discrimination and classification. Although having their own rights, these new models may also be considered as generalizations from two-class to multiple-class techniques. The LP model minimizing the -norm is similar to the MSD (minimizes the sum of deviations) models and that minimizing the -norm is similar to the MMD (minimizes the maximum of deviations) models for two-class classification. Properties of these new models are studied. The MSD model is immune to the difficulties caused by pathologies of earlier mathematical programming (MP) models for two-class classification although the MMD model is very limited in use.
Discriminant and classification analysis has been fundamental scientific research and practical applications. Discriminant analysis involves the study of the differences between two or more classes of objects represented by measurements, or variables, of different characteristics or attributes. Classification analysis involves the study of assigning new observations into one of the classes based on the measurements of the characteristics. Applications of discriminant and classification analysis are diverse. For example, reported applications in business include financial management, human resource management, and marketing; applications in biology and medicine include patient classification, disease diagnosis and species classification; and applications in environment and geography include remote sensing image pattern classification and pollution control. In fact, this study was motivated by the need to identify a few from many thousands of genes that can be used to classify tissue samples into two or more classes, such as normal and tumor tissues, and to identify genes responsible for certain diseases (Ambroise & McLachlan, 2002; Dudoit, Fridlyand, & Speed, 2002; Nguyen & Rocke, 2002; Sun, 2003; Sun & Xiong, 2003). The availability of large datasets collected using current information technology, such as the Internet, imaging and remote sensing, made the traditional discriminant and classification techniques inadequate. Discriminant and classification analysis techniques will play a more important role in data analysis as information technology advances and as huge datasets need to be analyzed with data mining tools.
Based on known values of the attributes or variables and known class memberships of the observations in a sample, discriminant functions are constructed. The attribute values of an observation can be evaluated by these discriminant functions to obtain discriminant scores based on which the observation is assigned to a class. For many decades, statistical techniques, such as Fisher’s linear discriminant function (LDF) (Fisher, 1936), Smith’s quadratic discriminant function (Smith, 1947) and logistic regression (Hand, 1981), have been standard tools for this purpose. Statistical methods perform well when the data analyzed satisfy the underlying assumptions, such as multivariate normality and equal covariance matrices of the independent variables, although minor deviations from these assumptions do not severely affect the performance of these techniques. More recently, other techniques, such as MP (Freed & Glover, 1981a, 1981b; Hand, 1981), neural networks (Stern, 1996) and classification trees (Breiman et al., 1984), have become alternative tools to rival statistical techniques. A revolutionary development in classification is the support vector machine (SVM) (Vapnik, 1995, 1998). A spectrum of techniques is needed because no single technique always outperforms others under all situations (Johnson & Wichern, 1988). | https://www.igi-global.com/article/linear-programming-approaches-multiple-class/40999 |
When I joined a group of journalists to visit US Bank Stadium in Minneapolis, not only was I impressed with what I saw, I had the pleasure of interviewing Brian Wolfe, HKS sustainable design manager and a key member of the architectural team for the stadium.
Our interview began with my question on the destruction of the former Hubert H. Humphrey Metrodome, the site where the new stadium was built.
Meyers: From the demolition of the Hubert H. Humphrey Metrodome to the design of the new stadium what were your driving considerations concerning sustainability?
Wolfe: The HKS team desired to create a state of the art multi-purpose stadium while keeping with the strict sustainable beliefs and goals of Minnesotans. This began with using the existing stadium site which allowed the opportunity for downtown revitalization and continued the connection with downtown amenities such as the public transit system, MetroTransit.
Additionally, over 90% of the Metrodome demolition materials have been diverted from the landfill. The stadium form and materials reflect its location and is responsive to the environment, which is true sustainability.
Meyers: What were some of the most difficult sustainability challenges facing this project and why?
Wolfe: A significant challenge was finding ways to condition an expansive volume in an extreme climate while meeting current energy codes. This drove the team to look at innovative ways of maximizing daylight for lighting and passive solar heating and how to allow the natural flow of air to benefit occupants. A reversible ventilation system that will recirculate captured warm air from the heat reservoir at the roof when in heating mode was created. Alternatively, the system will reverse when in cooling mode.
Meyers: Describe what in this project has LEED certification and how that challenge was addressed.
Wolfe: The project was initiated with a target for LEED New Construction Certification. To HKS, LEED was not the driving force for sustainability. Smart, sustainable design that looked at sustainability holistically was the driver.
The team then let the LEED points fall where they may. The project location allows fans the opportunity to benefit from numerous local amenities and a direct connection to public transportation, whether bus lines or METRO. Water reduction was achieved with the use of low-flow fixtures with sensor activation. A healthy indoor environment was created with products and materials having low to no Volatile Organic Compounds (VOCs).
Meyers: Elaborate on why ETFE was used for this project. Are you satisfied with the material and will you again recommend it?
Wolfe: Ethylene tetrafluoroethylene (ETFE) was used for its numerous benefits it offers the stadium:
- Reduced Structure – Strong and light weight material allowing for reduced tonnage of steel;
- Reduced Loads – The smooth surface allows for the snow and ice to slide off the roof into the snow catchment, thereby reducing dead loads due to snow and ice and maintaining the systems transparency during the winter;
- Thermal Transfer – The material allows heat to transfer for greater snow melting ability;
- Natural Light – Provides extensive natural daylight, thereby reducing the demand for artificial lighting;
- Passive Heating – Its transparency offers passive solar heating during the winter helping to heat the space and maintain desirable indoor temperatures, and during the summer this drives the stack-effect which will create natural air-flow and drive natural ventilation;
- Biophilia – Provides fans a connection to the outdoors like an outdoor stadium while being protected from the harsh outdoor environment;
- Embodied Energy – ETFE has extremely low embodied energy and low mass to area ratio – a three layer system has only +/-600 microns of total thickness – that’s 0.02” and the entire system weighs less than 1 pound per square foot;
- Thermal Property – The air between the foil layers drive the thermal performance – a three layer system has a higher thermal performance than an insulated glass unit at 1/10th the weight;
- Low-Maintenance – The non-porous surface makes the material low-maintenance as rain will clean the surface
The material’s versatility allows it to be used in various situations and it is anticipated to be used more extensively on US and international projects.
Meyers: From a standpoint of green building, compare this to other large entertainment complexes in the US.
Wolfe: US Bank Stadium will be one of the most sustainable domed stadiums due to the maximized use of natural daylight, extensive use of LED lighting and LED sports lighting, use of passive solar heating and reduced steel tonnage for a location that has the highest dead loads due to snow. Additionally, the stadium will provide a healthy environment with the use of low-VOC products and materials and a cleaning and pest management program that will utilize products that do not harm the environment. Recycling has been and will be a focus of the project from the demolition of the Metrodome to the recycling of construction and operational waste with the inclusion of a composting program.
Visitors will be offered tours of the stadium that will not only point out special design features of the stadium, but will also include a sustainable education component that will highlight sustainable strategies that were implemented.
Meyers: How effective is ETFE from a cost standpoint from both material and installation perspectives?
Wolfe: There is no other transparent material that could have been used in this long-span application at its price-point – installation was efficient allowing over 200,000 sq/ft of roof to be installed in approximately 4 months.
As the stadium nears its expected completion this summer, the Minnesota Vikings website adds this perspective:
“One of the most prominent design elements of the new home for Vikings football in 2016 is the glasswork that will feature a picturesque view of the downtown Minneapolis skyline. Located on the west side of U.S. Bank Stadium, work continues to ramp up on the glass curtain wall that houses the world’s largest five operable doors.
“As work continues, an LED video board will be placed on the west prow facing Medtronic Plaza. | https://greenbuildingelements.com/sustainability-drove-design-behind-us-bank-stadium/ |
Three Office Buildings Using Passive Heating and Cooling Design
Passive heating and cooling refers to techniques to manage the internal temperature and air quality of a building without using power. Here are three examples of new buildings where such techniques have been employed.
Modelling of the effects of heat gains throughout the year is first undertaken. For example, the solar gain experienced by the building is a function of the total daily irradiation on the building surface, the glazing area, the angle of incidence at which the sun hits the window, the transmittance value (g) of the glazing, and the area of floor or wall reached by the sunlight, as well as its airtightness , U-value and thermal mass.
The stack effect is a function of the pressure difference between the air outside and inside the building caused by their difference in temperature. The stack effect can in theory be utilized to cool a building without the need for artificial ventilation systems. In practice, with existing buildings, it is difficult. The relative size of the openings at the top and ground floor is important.
If the local prevailing wind is constant, the best result is obtained by having a small inlet and a large outlet. If the wind is not constant, a large inlet is preferable because it lets in a greater volume of air.
Ground level vented wall and/or window openings must be equipped with weather, burglar and insect-protection and use automatically-controlled flaps. If daytime solar gains are reduced to a minimum and the building is otherwise airtight, night ventilation can perform well. The building must have good passive stack ventilation design.
1. The Energon passive office building in Ulm, Germany
Air intakes for ventilation and cooling outside the Energon passive office building in Ulm, Germany. Source: International Energy Agency (IEA)
This is a triangular, compact building with five storeys, and has a physically curved facade enclosing a glass-covered atrium at the centre. This provides ventilation, and daylight. The building is a reinforced concrete skeleton construction with facades made of prefabricated wooden elements of largely equal dimensions.
Insulation is 20cm-thick under the foundation slab, 35cm in the facade, up to 50cm in the roof. The windows are thermally insulated triple glazing. Heat pumps and thermal stores help to moderate the temperature.
2. Office building at the Building Research Establishment, England.
Solar chimneys on an office building at the Building Research Establishment, England. Source: BRE
'Solar chimneys' are automatically opened when required to release unwanted hot air. Their height and metal composition allows them to be heated by the sun, which heats the air internally. This rises through the chimney, drawing up air from within the building.
3. The Solar XXI building in Lisbon, Portugal
The Solar XXI building in Lisbon, Portugal Source: International Energy Agency (IEA).
This building is a combined office and laboratory at the National Energy and Geology Laboratory (LNEG). This 1500m2 (16,146ft2) multipurpose building in Lisbon, Portugal, is naturally ventilated and functions as a near zero energy building. Its cost is said to be little more than a conventional building of the same size.
The office space is on the south side of the building to take advantage of daylighting and solar heating. Spaces with intermittent use, such as laboratories and meeting rooms, are on the other side of the building. Office spaces are in use from 9am to 6pm weekdays, and the ventilation pattern was arranged to suit this.
Plan and sectional view of the Solar XXI building in Lisbon, Portugal, showing distribution of the buried air pre-cooling system. Source: International Energy Agency (IEA)
The heat output of the PV modules is ingeniously used to supplement ventilation. There is an air gap behind each panel with openings to indoor and outdoor air at both high and low level, where heat from the rear of the panel causes a convective flow.
Seasonal performance. Cross (blue arrows) and vertical (red arrows) ventilation systems acting together with the buried pipes system (blue arrows on the right). Source: International Energy Agency (IEA)
In winter, the upper opening takes air indoors, either from outside or from the room, through the lower opening to be heated. In summer, the upper opening lets the warmed air outdoors. The lower opening can either be open to the room to provide ventilation or to outside to provide cooling for the PV panels only.
The building has high thermal capacity and external installation on the walls and roof. The south facade supports 100m2 of solar PV modules and the majority of the glazing. Additional space heating is provided by 16m2 (172ft2) of roof-mounted solar thermal that also supply hot water, which can be supplemented by a gas boiler.
The 18 kilowatt-peak (kWp; the rated power output under standard test conditions) grid-connected PV arrays supply electricity; further panels are located in a car park, where they also provide shade.
The entire system satisfies heating requirements of 6.6kWh/m2 and cooling requirements of 25kWh/m2. Annual electricity use for the building is about 17kWh/m2, of which 12kWh/m2 is from the PV arrays, leaving 30 per cent to be drawn from the national grid.
Natural lighting is encouraged. In the centre of the building a skylight provides light for corridors and north-facing rooms on all three storeys. The installed artificial lighting load is 8W/m2. There is no need for an active (powered) cooling system. Venetian blinds are outside the glazing to limit direct solar gain. Natural ventilation is promoted through the use of openings in the facade and between internal spaces, together with clerestory windows at roof level, which help create a cross wind and stack effect.
Assisted ventilation is provided by convection from to the PV module heat losses. To supplement this in the cooling season, incoming air can be pre-cooled by being drawn by small fans through an array of underground pipes as shown in Figures 2.40–2.43. The openings are adjustable, and air is allowed to rise through the central light well.
The vents are manually operable, and staff needed to be educated in their use. In other buildings, such vents can operate automatically, governed by sensors. The building's occupants have been surveyed and expressed 70–95 per cent satisfaction with aspects of the air quality and temperature.
These buildings show that with a little thought, buildings can drastically reduce their heating and cooling costs and increase the comfort of occupants.
David Thorpe is the author of
- Solar Technology: The Earthscan Expert Guide to Using Solar Energy for Heating, Cooling and Electricity
- Energy Management in Buildings: The Earthscan Expert Guide
- The 'One Planet' Life: A Blueprint for Low Impact Development
His Passive Solar Architecture Pocket Reference Book will be out later this year from Routledge. | https://www.smartcitiesdive.com/ex/sustainablecitiescollective/three-office-buildings-using-passive-heating-and-cooling-design/1088807/ |
This ecologically orientated renovation project demonstrates the importance of setting environmental priorities and staging work over time to suit client needs and budgets. The Sustainable House Builders’ holistic ethos assisted with establishing these priorities and achieving significant environmental and social improvements.
The Client Brief: The existing four bedroom house was a deep plan, brick veneer building built in the 1980’s after the federation style. The house had some poorly located rooms in terms of solar aspect, which when combined with small eaves and limited ventilation openings required extensive use of air-conditioning to make the house habitable in the warmer months. The client had a rather vague brief; as well as some renovation work to the existing house. They were looking for some ideas to address a poorly utilised outdoor area with a south westerly aspect attached to the informal living area. The site was large, but despite featuring a pool and tennis court the outdoor areas were largely underused as there were no comfortable outdoor spaces nor connectivity for entertaining or for the children to play in.
DESIGN:
The design team recognised that the process of establishing the client brief was one of the most important phases of the project. They took a holistic approach that considered the family’s present and future needs and financial capabilities. Considering how best, a small renovation could improve the overall performance of the house. The result was a staged proposal. Stage one addressed the outdoor area with a large verandah extension adjacent to the house, some rainwater collection, and minor renovation of some of the upper level bedrooms. Stage two introduced a thermal chimney/ atrium into the centrally located stairwell which provides light and ventilation to the deep plan house, as well as the addition of more rainwater storage, a solar hot water system and insulation to the roof and walls. Stage three will see the implementation of permaculture gardens using greywater irrigation and a new ‘living wall’ to protect the upper level bedrooms from the western sun as well as to protect the bathroom and provide it with ventilation opportunities.
Construction materials: The pavilion-like pergola extension is predominantly constructed in a combination of steel, for primary structural elements,locally sourced recycled hardwood timber and laminated plantation pine beams. High level battens are completed in a proprietary composite material manufactured from recycled plastic and sawdust that is expected to require little or no maintenance. Drop-down plywood feature panels mark the location of the outdoor dining table and provide a ceiling to frame the space into which compact fluorescent lighting is recessed.
Shading: The existing house was poorly shaded to the south and west, with no significant vegetation and limited eaves overhangs. The extension provides protection to the family living areas which open out onto it from the harsh west sun. The pavilion roof provides upper level shelter whilst opening to the north allowing in desirable low oriented winter sun. Landscaping and ‘living walls’ have been used and proposed down the western side of the house to provide further protection. The north east of the house is protected by an existing verandah and some significant trees. The plywood drop panels have been positioned to the south-eastern side of the pavilion extension, to maximise winter morning sunlight. The mass shading provided to the house has also created a lot more visual privacy. As a result the house can be opened up and outdoor areas can be used without onlooking or overlooking neighbours.
Ventilation: The existing house featured French windows but was poorly ventilated. While there are plans in future stages to further address this, the stage one renovation made a huge difference by just opening up the back wall with a large bifold door. This has enabled air to be pulled and directed right through the house from all areas of the ground floor as well as forcing ventilation into the upper level circulation area. The effect is further enhanced by the sustainable home design of the verandah extension; the high edge of its roof sits over one metre above the existing house roof ensuring that hot air can be expelled. The second stage of work proposes a thermal chimney over the central stairwell. This will draw air from the open planned informal living areas on the ground floor.
Cooling Systems: The existing air-conditioning unit sits in the middle of the wall of the existing dwelling at the edge of the extension. Previously, not only did it have to cool an unprotected sizable area, subject to the full force of the western sun, with the unit itself was subject to that same western sun thus working very inefficiently. On the result of a cost analysis and availability of an alternative location, the unit has remained institute. Being now incorporated into a battened enclosure which screens both the unit and the associated pipe work. Acting now primarily as the main serving bench for the verandah entertaining space. The shading provided by the pavilion of the pool, allows maximum evaporative cooling whilst uncovered via the full opening of the bi-folding doors to the internal living spaces. Subsequently, since the addition of the pavilion extension by sustainable house builders, the residents have not found it necessary to turn the air-conditioning on, even during peak summer periods. The choice of floor material being masonry pavers, provides valuable thermal mass for cooling the home with summer shading, as well as providing passive heating of the adjacent living spaces by slow release of great winter sun solar gain. The rain water tanks provide substantial thermal mass properties also by shielding and cooling of the direct pavilion environment.
Lighting: A complete audit of the home’s lighting was conducted so that the house could be fitted with more energy efficient lighting layout. The introduction of the daylight into the centre of the deep plan house through the proposed thermal chimney/atrium will reduce if not eliminate the need for artificial lighting during the day. The inspiration of this passive lighting benefits not only the central circulation areas but most importantly flooding the upper level of the home with priceless energy neutral light and ventilation. Artificial lighting for the extension is all from 240v compact fluorescent globes and provides alternative lighting for the tennis court that reduces the need for the power thirsty court lights when the area is being used for general play by the children.
Rainwater: Three rainwater tanks with a total capacity of approx. 15,000 litres total have been installed as part of stage one. They are located to the west of the outdoor space helping to buffer the afternoon sun. The tanks were plumbed to the house ready to be connected to all services inside the house as part of a later stage of works. At the moment the collected rain water is being used for wash down, irrigation purposes and for pool top up. There was also another tank installed towards the other end of the property next to the garage structure, this bringing the total rainwater storage capacity of the site to approx. 28,500 litres. A pool blanket was installed to reduce evaporation, provide solar heating and reduce heat loss whilst minimising fossil fuel energy use for sanitising the water.
Landscape: One of the main features of this renovation was the integration of the landscape into the design. The colorbond roof cladding of the verandah, has been phased in the southwest corner with polycarbonate sheeting, buffering harsh summer sun as natural filtered light through random under battens. A pleasing feature allowing the garden to thrive as it extends well beneath the protection of the roofline. Tensioned steel cables, ladder from the landscape to the roof structure allowing for vines to climb into the structure itself. The intent is to act as a living, active, cooling corner within the outdoor space, serving to filter and cool breezes for both direct external and internal air quality and temperature. Garden beds to the extended edge of the extension assist in filtering out the dust which filters off the crushed granite tennis court. As part of stage three a deciduous vine will be incorporated into a ‘living green wall’ which will protect the children’s rumpus room minimizing artificial lighting by shedding it foliage to allow in desirable winter sun. There has been a focus on productive gardens and where possible vines and edible plants have been chosen. The vines as part of stage one are passionfruit and the intention is to provide a raised vegetable garden down the side of the house as part of stage three.
EVALUATION:
The principle focus of the sustainable home designs team on passive design, incorporating total integration of landscape, achieved through microclimate control, has greatly improved occupant comfort whilst achieving a massive reduction in the use of fossil fuel sourced energy. Water harvesting and water conservation strategies enable maintenance of the thirsty pool for summer comfort refuge whilst providing the potential to meet new stringent water usage targets. The social connectivity and interaction inspired by natural and passive elements of the pavilion structure has undoubtedly improved the comfort, health and quality of family life. | https://www.sustainable.id.au/retrofit-at-mount-ommaney/ |
- By 2030, a building designed to the forthcoming Part L will perform worse than its 2010 equivalent.
This is because, to meet new airtightness requirements, designers are abandoning natural ventilation for active cooling strategies, such as mechanical ventilation or air conditioning. Results are from ongoing research for RICS on climate, published in the report Non-Domestic Real Estate Climate Change Model (2011).
In the UK, standards are devised with a focus on heat losses in winter as their main source of climatic risk, but as the climate starts to change, there will be greater concern about summer heat gain, for all building types. Building Regulations still focus on the thermal isolation of buildings from their environment, which has been very beneficial to reduce heating loads in winter. But the regulatory approach needs to shift towards deciding how to dissipate excessive internal heat during warm seasons without increasing energy demand. More and more restrictive envelope requirements without an appropriate cooling approach compromises future buildings’ energy efficiency and economic sustainability.
- The embodied carbon emitted in the construction of tighter and more thermally resistant envelopes can be 10% higher than the operational savings that they cause.
As the climate changes, the carbon savings achievable through tighter and thermally more restrictive envelopes will shrink. In some cases, building envelopes will end up emitting more carbon through the manufacture of additional membranes and materials than they save in operational terms over their life.
02 / The thermal impact of new building regulations and climate change
The new Part L of the Building Regulations will be enforced and the thermal characteristics of new buildings’ envelopes (U-values) have been further restricted. This trend started after the 1970s oil crisis, with the aim of improving energy performance throughout the building stock.
However, stricter U-values do not always lead to “better energy performance”. The Building Regulations define this as a lower heat transfer through the walls, roof, windows and floors. In winter this has benefits because heat does not transfer through the envelope. However, in warmer months, many buildings produce too much interior heat from lighting, computers, hot water or people. This leads to an opposite requirement of energy transfer to avoid overheating. Stricter U-values make this transfer more difficult.
As well as the reduction of U-values, regulations have limited the maximum amount of uncontrolled air exchange (infiltration or air leakage) between interior and exterior, while ensuring enough controlled air supply and extraction for satisfactory use of the building (ventilation). In cold weather, controlling infiltration has a positive impact because heating energy and costs are reduced and the heat produced inside the building by lighting, people and equipment helps to warm up spaces.
However, in hot weather problems arise again. Infiltrations traditionally helped to dissipate internal heat, but in airtight buildings ventilation needs to take this role. This can be achieved through a wide range of systems, from natural ventilation to the exclusive use of air conditioning.
Whether buildings currently on site are future-resilient is unclear. The main question is how hot the climate will become. The answer is not unambiguous: it all depends on how much carbon is released to the atmosphere. Intergovernmental Panel on Climate Change predictions are probabilistic and consider high, medium and low emissions scenarios. The bad news is that low scenarios are not calculated any more, as they are very unlikely to happen.
As an illustration of how the UK’s climate is likely to change, recent studies have shown how south Hampshire’s climate in 2080 might be very similar to the current climate in south-west France. This is already having an impact in the real estate market as French wine producers are purchasing rural land in Britain.
Are new buildings ready to endure the climate of Mediterranean countries? Naturally ventilated or mixed-mode buildings will have to deal with higher overheating pressure. The possibility of using external air for natural ventilation and passive cooling helps mitigate the problem in an efficient way. However, higher external temperatures will reduce the efficiency of these strategies.
On the other hand, large numbers of buildings in sectors like office, retail, hospitals and sport centres, are designed to provide ventilation exclusively using air conditioning. If natural ventilation or passive strategies are not implemented to help dissipate internal heat, cooling loads and energy bills will rise, and emissions targets might not be met.
03 / Research: the effect of airtightness and climate change in buildings*
Evolution of cooling and heating demand with climate change
Following climate change, not only will summers be warmer, but heat waves will also be more acute. Both factors will trigger the demand for cooling. Figures 1 and 2 show the total energy demand for heating and cooling that will be required. Four buildings constructed under different constructive approaches have been modelled. The total energy reduction of upcoming 2013 Building Regulations compared with 2010 results will be very limited and will decrease as global warming advances.
The 2013 regulations will further reduce heating demand, but this reduction is significant only in relative terms - the absolute values are not that great. On the other hand, the increase in cooling demands will reduce the total performance of new buildings.
Older buildings demand more energy mainly because their heating loads are currently high. As most of their demand is required for heating, following global warming, their energy demand will decrease.
Impact of current Building Regulations on design
To avoid interior overheating, cooling loads can be dissipated using many solutions, ranging from the exclusive use of natural ventilation to the exclusive use of air-conditioning, which has a high energy use impact. Between those extremes, designers can choose between many strategies to meet demand, such as passive cooling or mechanical ventilation (with or without heat recovery), that consume different amounts of energy.
Our simulations for office buildings show that as a consequence of making buildings more airtight and reducing their U-values, many new naturally ventilated buildings in London (following either 2010 or 2013 regulations) would already suffer from overheating in summer. Results show that office buildings exceed CIBSE’s recommended thresholds for overheating hours when complementary passive or active strategies are not implemented. Buildings constructed in 1976 will follow the same path after 2030 and older buildings after 2050. Infiltration is currently helping older buildings to cool down during summer.
These overheated buildings will require deep retrofit or the installation of new cooling systems to maintain interior comfortable levels. Consequently, many designers are turning to mechanical ventilation or air conditioning systems as the solution. Active strategies such as mechanical ventilation with heat recovery (MVHR) or air-conditioning can also be implemented as complementary tools to natural ventilation, although in many cases they are provided as the main source of cooling and heating. In the most extreme cases, natural ventilation is completely overridden and users cannot open windows or interact with the system. In any case, active systems need to be appropriately commissioned and maintained to remain efficient, and this is not always the case.
Figure 3 shows the difference in energy performance between a naturally ventilated building designed following 2010 regulations and the same building designed after 2013 with an MVHR system. The 2013 building would overheat by 2030 if only natural ventilation was used, while the building designed with leakier 2010 regulations can avoid overheating until 2050, when it will need air-conditioning.
If the MVHR is properly installed and used, the building constructed following 2013 regulations would avoid overheating until approximately the same year as the naturally ventilated building, and energy would be saved. However, if the system is used inefficiently, by 2030 the energy used by the fans would be higher than that required by its 2010 equivalent. Following climate change, the energy demand will increase.
Moreover, when mechanical ventilation is used to cool down the building in summer, users feel overheating earlier. According to the adaptive comfort approach for naturally ventilated buildings, users’ comfort expectations are stricter when natural ventilation is not used.
Effects on energy bills and energy demand following climate change
Cooling is almost always supplied by electricity, which is one of the most expensive sources of energy and its price is expected to continue rising in the future. In buildings with air-conditioning as the only cooling strategy, bills will increase dramatically (see figure 4).
Electricity demand in older buildings will also soar, but at a lower level - cooling loads will increase, but to a lesser extent due to the higher infiltration rates. In mechanically ventilated buildings, the absolute values will be lower, but the trend will be similar.
Older buildings currently have higher heating loads, but following climate change, these loads will decrease (as warmer climate requires less heating). All in all, their bills will also increase, but at a lower rate and their final expenses will be lower than those of newer buildings.
Furthermore, with cooling demand in newer buildings expected to rise by 20-25% by 2050 and by up to 55% by 2080, cooling systems currently being installed may not be able to cope with the demand and will need upgrading (see figure 5).
*Findings in this section have been calculated with building simulation of indicative buildings located in London (see methodology).
04 / Research: whole-life carbon analysis
Whole-life carbon analysis is a methodology to quantify all CO2 emissions released by a building from the moment that materials are extracted for construction purposes until the constructed elements need to be demolished and disposed of.
The European standard CEN/TC 350 identifies four stages in the life of a building:
- Product manufacture This encompasses the extraction of raw materials, their transport to a point of manufacture and the process of transforming them into construction products. In the production of reinforced concrete, this stage would include the emissions associated with extraction and production of cement, sand, gravel and steel and their manufacture into any structural element.
- Construction This stage involves transportation of construction products to site and the on-site processes involved in assembling them into buildings.
- In-use stage This includes maintenance, repair, replacement and refurbishment of the buildings, as well as the use of energy and water during its occupation.
- End of life All buildings have an end of life where they are replaced due to obsolescence or having reached the end of their safe working lives. In this stage, the emissions are calculated from dismantling and disposing of the elements of the building.
For each of the above lifecycle stages, more detailed sub-categories breakdowns exist. Please refer to EN 15804, which was published early in 2012 and establishes product category rules for environmental product declarations, and BS EN 15978 - published in 2011 - which brought the CEN/TC 350 standards into the UK.
For a more general overview, please refer to Sturgis Carbon Profiling’s guidance document as published for the British Council for Offices: www.bco.org.uk/Research/Publications/WholeLife2565.aspx
Embodied carbon
- Building to more restrictive standards leads to higher emissions.
The embodied carbon is the CO2e emitted in the material development of the building. It encompass the emissions produced during the product manufacture, construction and end-of-life stages, together with the maintenance of the materials.
Achieving tighter buildings and a more thermally efficient envelope requires more materials to be manufactured and transported on site (thicker insulation, tighter wall finishes and so on). Figure 6 shows the embodied carbon of three different envelopes that would comply with upcoming 2013 Building Regulations. Their carbon impact is in all cases higher than a baseline cavity wall that complies with 2010 regulations. The variation ranges from 20-40% more emissions.
The final step to understanding the whole-life carbon impact of upcoming regulations is to add the operational emissions to the picture and compare the results. Figure 7 only includes the embodied carbon of constructing the envelope of the building because it is the only element that varies between the options. The operational emissions are calculated for the heating and cooling loads of an air-conditioned building over an average lifetime of 60 years. The expected decarbonisation of the grid has been also taken into account.
The differences between the three options and the baseline show that, depending on the type of construction, the energy savings achieved by reducing the energy transfer through the envelope might be jeopardised by the extra carbon emissions required in the construction of the building elements.
05 / Lessons learned
Energy demand
At present, infiltration is helping some older buildings to cool down during warm seasons. However, infiltration is not the solution to the problem, but the evidence that something is not being addressed properly in new buildings. Airtight buildings combined with the exclusive use of active cooling strategies - mainly air-conditioning - increase energy demand and boost energy costs.
Communication between building envelope and HVAC designers is crucial. Designers should focus on the use of natural ventilation and passive tools unless high exterior temperature make air -conditioning indispensable to achieve comfort.
Air-conditioning should be a last resort. A building dependent on air-conditioning will be subject to severe climatic risk.
In summer, natural ventilation should be available in every building. Users should be able to open windows - at least partially.
Occupants need to understand how to use their buildings, particularly as weather becomes warmer.
Controls have to be simple and intuitive.
The UK will soon have to be more concerned about the risks that hot weather poses to the built environment, rather than the risk of cold winters. Heat transfer through the envelope in winter is not the main issue any more. The emphasis of Building Regulations has to shift accordingly. This means restricting the use of active cooling systems and promoting the use of passive ventilation and cooling strategies.
Embodied carbon
The extra carbon emissions released during the construction and maintenance of tighter envelopes will counterbalance the savings achieved by reducing cooling and heating loads. Designers need to:
- use low embodied carbon materials in delivering enhanced thermal and airtightness performance, such as aerogel, or natural building products, such as hemp or wool
- design durable elements to perform dual functions such as weathering and airtightness
- minimise solutions that require higher maintenance to achieve required airtightness
- integrate service voids to avoid damaging airtight layers during servicing renewals or phasing of works on site.
Methodology and assumptions
The results shown in this article have been obtained from the simulation of an indicative three-floor office building in London. London is the UK city where temperature is expected to rise most due to the combination of global warming and a more intense urban heat island effect. Construction standards are taken from four key periods: the Victorian era following traditional building techniques (1900); the 1970s after the oil crisis (1976); last year (2010) and this year (2014).
Values for 2013 Building Regulations assume that the thermal requirements for the envelope will be 20% more restrictive and the maximum possible infiltration will be halved (following current Part F recommendations).
Future building performances have been calculated in 2015, 2030, 2050 and 2080 using UKCP09 weather files (medium emissions scenario, 50th percentile). Internal loads and occupancy patterns follow CIBSE recommendations. Simulations calculate annual heating and cooling demands for standard working hours. Boiler and heat pump efficiencies have been considered, and 40% unprotected glazing is considered in every facade. Calculated loads are as design and do not include the performance gap between design and real values.
The model has been calibrated comparing results with suitable benchmarks - CIBSE, BRE, TM46 and Carbon Buzz.
Results for latest Building Regulations do not take into account maximum target emission rates (TER) defined in 2010 and 2013. TERs are variable and compliance can be achieved following a range of approaches that not always focus entirely in the envelope or HVAC system.
The approach followed in this article focuses on the quality of the envelope exclusively, allowing like-for-like comparisons between energy demand in buildings constructed at different historical moments.
Acknowledgements
The author wants to thank Gareth Roberts and Theodore Darviris for their support in preparing this article. | https://www.building.co.uk/whole-life-carbon/whole-life-carbon-overheating/5067511.article |
The motivation for writing the thesis was the realization that the warming of the climate is an ascertained problem and a reduction in the energy consumption is necessary to counteract the phenomenon buildings account for 40% of the worldwide energy consumption, then the adoption of passive cooling strategies, such as. Priyanka padmanabhan nayar (2012) improving thermal comfort in residential spaces in the wet tropical climate zones of india using passive cooling techniques: a study using computational design methods morgan wiener ( 2012) unitized double skin façade assemblies: achieving the needs of future. Environmental passive architecture with special reference to residential buildings in greater cairo a thesis presented in partial fulfillment of the requirements for master of science degree in architecture engineering by mohamed abd elmohsen dardir ahmed bsc in architecture 2006 – ain shams university. Passive cooling and energy efficient strategies for the design of a hotel on the southern coast of pernambuco, brazil thesis msc architecture, energy and sustainability learn, london metropolitan university september 2003 luiz busato. Hotels 50 - 70 25 245 indoor comfort research in malaysia 26 26 passive cooling 29 261 overall thermal transmittance value (ottv) 30 262 thermal mass 34 tropical climate: energy consumption and users' satisfaction in selected office buildings in malaysia phd thesis university of liverpool iso 7730.
I wish to thank my interviewees for imparting the required information for this thesis especially, issac a entails facing challenges regarding both heating and cooling energy demands in buildings since the late 70s implemented by using general passive design strategies, traditional architecture elements and innovative. At an architectural scale, this project attempts to tackle the problem of face-to-face human interaction within a desert climate how far can architects harness the power of the beating sun to conversely create places where people meet and assemble historic precedents of pre-electric passive cooling in the. He works in the fields of energy efficiency in buildings, passive systems for cooling and ventilation, solar thermal systems, and energy policy modelling he has published 18 research papers in referred journals, presented 35 papers on international forums, authored/edited five books in the field of energy efficiency and.
Passive cooling techniques 21 history of buildings high consumption of electricity for mechanical cooling has already caused power outages in some developed countries such as greece as was mentioned before first of all, we have to go back to the roots of architecture and search for alternative solutions in ancient. Passive cooling techniques are the method to increase the comfort level without or less usage of mechanical methods the climate in tamilnadu region is warm and humid and the temperature ranges from 30˚to 35˚c and 25˚ to 30˚ in summer and winter respectively solar passive architecture cooling.
In this thesis the traditional vernacular houses in libya have been used as a vehicle of the research traditional vernacular architecture in libya, which is conceptually understood as a shelter that fulfilled house sets of passive heating and cooling strategy have been underlined from each of the three. School of architecture the efficient strategy of passive cooling design in desert housing: a case study in ghadames, libya ali hassan eltrapolsi thesis submitted in partial fulfilment of the requirements of the award of doctor of philosophy major subject: architecture. Wind towers or wind catchers are small towers installed on top of buildings wind towers have different shapes and structures for centuries wind towers have been used for ventilation and cooling of buildings in the hot and arid or humid areas wind towers are still used in some areas of middle east and egypt (figs. Advisor: timothy e johnsonalthough they represent a reasonable alternative for mechanical evaporative coolers, these systems suffer from their limited applications in terms of air circulation and small rate of heat transfer in this thesis , a new air scoop is developed to overcome the above mentioned limitations basically.
Retrofitting passive cooling strategies to a brisbane school: a case study of the physical and social aspects lisa johanna kuiri b architecture (iib), university of queensland, 1992 b design studies, university of queensland, 1989 a thesis submitted for degree of master of philosophy at the university of queensland. Passive cooling glossary bibliography biographical sketch 1 introduction passive solar heating, cooling and lighting techniques have reached a high degree of technical maturity large scale the implementation of new approaches to solar thermal energy in architectural design was the theme of several research. 0 an experimental study of designed passive elements for energy efficiency in buildings in composite climate thesis submitted in partial fulfilment of the requirements for the degree of it is feasible to reduce consumption of energy usage for heating, cooling and lighting requirements of a building by adopting a. | http://npcourseworkffrm.n2g.us/passive-cooling-architecture-thesis.html |
Client: Construction Dept. I.D.F.
Built area: 900m²
Structural engineer: Avraham Soffer, Tel Aviv
H.V.A.C. Consultant: Amos Halfon
- The Area
The site is in an industrial production zone inside a large army base, in the Inner Shfelah Region, an area with cool winters, and hot summers with moderate humidity.
The army policy is not to provide any mechanical heating or cooling for work places in this area.
- Design Concept
The challenge of this project was to create a working environment providing the maximum level of comfort without mechanical heating or cooling.
Computer assisted design studies showed that passive solar heating could easily achieve comfort conditions for most of the winter, while controlled daylighting which eliminates cooling load from artificial lighting, coupled with night ventilation cooling, could greatly increase summer comfort conditions.
These aims were translated into a series of south-facing roof clerestroy windows, providing winter passive solar direct gain heating, and high level of diffused daylighting to work surfaces through system of light diffusing baffles.
Summer night ventilation is assisted by fans mounted in clerestory windows, and internal air movement created during the summer working hours with ceiling fans when necessary. | http://www.elr-arc.com/english/portfolio/zrifin.html |
The building is located in a residential area in the municipality of Marousi Athens. The block consists of three office buildings from which the east building is the A.N. Tombazis and Associates Office Building.
The total building area is 1100 m2. The design is developed in three levels, and basement with parking area.The two long sides of the Office Building are facing east and west. For reasons of bioclimatic design, the building is narrow and long, approximately 8 x 35 m. Thus all workspaces are adequately supplied with daylight through side windows. As many as possible of the mature olive trees that existed on the site have been saved or transplanted. An important feature of the landscaping is the pond, a sculpture by G. Zongolopoulos and the wooden decks that lead to the entrances of the buildings.
The interior of the building is one open space developed on three split level decks interconnected at two points by two open steel stairs with wooden treads that have been designed in such a way, so as to provide minimum visual obstruction. Metal trusses support the concrete slabs of the different levels of the building. In order to combine the structural and mechanical depth and increase the perception of openness of the interior space, metal trusses support the concrete slabs of the different levels of the building. Outdoor indoor climate
Microclimate:Suburban
Average ambient temperature:
January: 10ºC
July: 26.5ºC
Global irradiation: 1581 kWh/m2
Sunshine hours: 2818 h
The present office building is an interesting example of a well designed building from architectural and energy point of view. The shape and the orientation, as well as, the interior planning of the building (it is an open space) give the possibility to exploit the local climate for energy conservation and daylighting purposes. The installation of a BEMS gives the possibility to control all the systems (such as ceiling fans, night ventilation fans, etc.) installed in the building as well as to monitor energy consumption. The building is also equipped with 7 split and 2 single package air-to-air heat pumps for cooling and heating purposes (back up system). Rainwater is collected and used for irrigation and flushing of the double mode toilets.Passive Design Measures
Lighting
The shape of the building and the location of the workstations, near the windows, allow an efficient use of the daylight. The building is entirely daylit from both sides by windows and from the roof by way of clerestories. Also, these clerestories are equipped with reflective curtains (Figure D-1) in order to distribute the daylight “deeper” in the building.
- The building including most of the basement is naturally lit by means of sill to ceiling windows that area provided on both long east and west facing facades and clerestories above the two stair wells.
- The east- and west-facing windows are provided with exterior fabric awnings positioned at approximately 15 cm from the wall, which provide both shading and glare control.
- The south-facing clerestory is provided with a light shelf on the south side.
Ceiling recessed downlights and task lighting compose the artificial lighting system. Artificial lighting is used only in case natural lighting is not adequate. The control of the artificial lighting system is manual on/off.
Another important element of building is the shading devices. They are exterior blinds for the windows and interior blinds for the skylights. The material is white plastic cloth, and its height can be adjusted, through a rotation mechanism. On the last level of the building, skylights are constructed, in the middle of the ceiling. They are covered with panels of cloth, which hang from the roof.
Ventilation and Cooling
Special attention has been paid to a combination of natural ventilation and passive cooling with mechanical ventilation. A central unit controls the system. In this region, the heating and cooling loads of an office-building normally cause high electricity demand. The following extra measures are taken:
- Natural cooling is achieved by evaporative cooling due to the presence of vegetation and water pond, by solar protection of the building shell and by cross ventilation.
- Ventilation and cooling is achieved by cross-ventilation, when appropriate and by automatically controlled ceiling fans, which extend the comfort range from 25°C to 29°C. When temperatures exceeds 29°C a zoned all-air heat pump back-up air-conditioning system turns on.
- Cooling is further enhanced by radiation by the mechanical night ventilation provided by two extraction fans on the roof, which by way of the lower night time exterior temperatures provide a temperature drop of about 3°C the next day.
- The thermal mass of the building is very high.
Insulation
The exterior of the building is clad with fair-faced cement bricks and has increased 10cm insulation. The U-values of the ground floor, roof and external walls are 1.41 W/m2K, 0.45 W/m2K, and 0.40 W/m2K respectively.
Acoustics
Acoustics have been given special attention due to their importance in the large open interior space. Metal acoustic panels are suspended from the concrete decks of the different levels in an open configuration that allows for movement of air between the panels and ceiling. | https://www.buildup.eu/en/practices/cases/meletitiki-alexandros-n-tombazis-and-associates-architect |
Most people's brief requirements include sustainability. This demonstrates how, over the last decade, peoples understanding of 'green building' has shifted from commercial building projects to their home building projects.
Other than complying with building regulations, there is no benchmark for residential projects. As in every project, budget and aspiration must always be balanced.
These are some of the most common questions about 'green building.'
Q: How much does it cost to build green?
Every green building design requires a very detailed unique approach from the start. Green materials are generally more expensive, and higher costs are associated with the design time needed to address material and product selection priorities. The budget can sometimes be more easily managed in a new build because all the components are much easier to coordinate.
Q: How do you design a building that saves energy?
Looking at ways to reduce heat loss and maintain a comfortable temperature throughout the day and year, whether as a retrofit or a new build, reducing the need for artificial lighting and mechanical heating and ventilation.
The following are some key considerations:
1. The walls are lined with internal insulation.
2. External insulation to the outside of the building.
3. Replace single glazed units with double or triple glazed units.
4. Using roof overhangs to provide solar shading to glazing where necessary.
5. All flat roofs can have green roofs.
6. Use stack and cross ventilation to increase natural ventilation.
7. Low-carbon product specifications
8. Low-VOC product specifications.
9. Wherever possible, specify renewable and recycled materials.
Q: What steps do you think are essential to take to achieve a "green building"?
When attempting to reduce your home's energy burden, a fabric-first approach is critical.
In order of most significant budget impact, we recommend the following:
1. Ensure that all walls are adequately insulated.
2. Replace or upgrade the glazing.
3. Plan any changes to the building to increase natural light levels, reducing the need for artificial lighting and maximising passive solar gain. Take advantage of the building's natural orientation.
4. A MVHR unit is an excellent system for taking cold fresh air and heating it with warm stale air.
5. Solar Hot Array - Use the sun to heat your water.
6. If you're lifting the floors on the ground floor, consider installing a water-based underfloor heating system. This operates at a much lower, more consistent temperature, allowing you to avoid costly and difficult-to-manage heating spikes.
7. If you have a flat roof with a sound waterproofing layer, consider installing a lightweight green roof finish to reduce rainwater runoff and increase biodiverse habitats.
Q: Will I notice a difference in the way I live and enjoy the spaces daily?
While most of the techniques listed above are hidden or passive, they will significantly impact your day-to-day life. It does, however, necessitate a new way of thinking about how to use your home. Green buildings are more responsive to the environment, accumulating heat and cool throughout the day and night. Temperatures and thermostats must be set ahead of time to reflect usage patterns. Reduced artificial lighting and increased natural ventilation have been shown to improve mental health and protect the fabric of your building. It's not about making money from the grid or saving on bills; it's also about creating better spaces that are more environmentally conscious and enhance wellbeing and everyday life.
Enter your details below and we'll be in touch. | https://www.modus.co.im/2021/07/28/how-focused-should-i-be-on-sustainability/ |
In the previous topic, Electrical Load Classification and Types – Part Three , I indicated the differences between Linear and Non-Linear electrical Loads and explain the effects of using Non-Linear loads in electrical design.
And today, I will explain the electrical loads calcification and types according to the load function.
You can review the following previous topics for more information and good following.
Third Classification of Electrical Loads: According To Load Function
The electrical loads will be classified according To Load Function as follows:
- Lighting Electrical Load.
- Receptacles / General / Small Appliances Electrical Load.
- Power Electrical Loads.
1- Lighting electrical loads
a- What is light?
Visible light is electromagnetic radiation with a wavelength that is visible to the eye
b- What are the main sources of light?
there are two main sources of light which are as follows:
1- Natural light (day light or sun light) source
Sunlight is electromagnetic radiation by sun and which includes the full spectrum of visible light (as well as frequencies beyond the sensitivity of the eye, known as ultra violet and infrared)
2- Artificial light sources
Artificial light sources are other sources of light which developed to compensate for /assist the natural light. It will have different frequencies and wavelengths that determine the light color.
Effects of Using Day Lighting Source in Electrical Design
A Particular attention must be given to day lighting while designing a building lighting system due to the following:
- Day lighting is used to maximize visual comfort inside the buildings.
- Day lighting is used to reduce energy use by the following methods:
- Reducing the use of artificial (electric) lighting by simply installing fewer electric lights because daylight is present, or by dimming/switching electric lights automatically in response to the presence of daylight.
- Using passive solar technology for heating or cooling different spaces inside the building.
2- What are the main characteristics of day lighting source?
- The daylight entering a building may include direct sunlight when the window has a view of the sun, as well as diffuse sunlight that has been refracted by clouds, and reflected from various surfaces such as clouds, ground or other buildings.
- Daylight can therefore vary greatly with weather conditions, ranging from total cloud cover to clear sky with direct sunlight.
- The effectiveness of daylight as a light source is measured as the “Daylight Factor”.
Daylight Factor
It is the ratio of internal light level to external light level and is defined as follows:
DF = (Ei / Eo) x 100%
Where:
Ei = illumiance due to daylight at a point on the indoors working plane,
Eo = simultaneous outdoor illuminance on a horizontal plane from an unobstructed hemisphere of overcast sky.
- Daylight factors are used to determine if the natural lighting levels in a space will be sufficient for the occupants of the space to carry out their normal duties.
- Calculating daylight factors requires complex repetition of calculations and thus is general undertaken by a proprietary computer software product such as Radiance.
- CIBSE Lighting Guide 10 (LG10-1999) which broadly bands average daylight factors into the following categories:
- DF Under 2 – Not adequately lit – artificial lighting will be required.
- DF Between 2 and 5 – Adequately lit but artificial lighting may be in use for part of the time.
- DF Over 5 – Well lit – artificial lighting generally not required except at dawn and dusk – but glare and solar gain may cause problems.
3- What are the types of day lighting technologies?
there are two types of technology that are used for utilizing the day lighting source as follows:
1- Active day lighting
It is a system of collecting sunlight using a mechanical device to increase the efficiency of light collection for a given lighting purpose. Active day lighting systems are different from passive day lighting systems in that passive systems are stationary and do not actively follow or track the sun
2- Passive day lighting
It is a system of both: collecting sunlight using static, non-moving, and non-tracking systems such as Windows, Sliding glass doors, most skylights, light tubes, and reflecting the collected daylight deeper inside with elements such as light shelves. Passive day lighting systems are different from active day lighting systems in that active systems track and/or follow the sun, and rely on mechanical mechanisms to do so.
4- What are the Common Methods for using Passive day lighting technology in a building?
there are many methods for using Passive day lighting technology in a building but the common ones will be as follows:
1- Windows
Windows are the most common way to admit daylight into a space. Their vertical orientation means that they selectively admit sunlight and diffuse daylight at different times of the day and year.
2- Skylight (see fig.1)
|fig (1): Skylight Lighting|
It is any horizontal window, roof lantern placed at the roof of the building, often used for day lighting. Generally it is made from White translucent acrylic which makes the transmitted light to be perfectly diffused and distributed evenly over affected areas and reduces the transmitted heat inside the building. Skylights admit more light per unit area than windows, and distribute it more evenly over a space.
The optimal area of skylights varies according to climate, latitude, and the characteristics of the skylight, but is usually 4-8% of floor area.
With proper skylight design, there can be significant energy savings in commercial and industrial applications up to 80 percent according to the US Department of Energy's Federal Energy Management Program. In terms of cost savings, the DOE reported that many commercial buildings can reduce total energy costs by up to one-third through the optimal use of day lighting.
3- Light shelves (see fig.2)
|fig (2): Light Shelves|
Light shelves are an effective way to enhance the lighting from windows on the equator-facing side of a structure, this effect being obtained by placing a white or reflective metal light shelf outside the window.
Usually the window will be protected from direct summer season sun by a projecting eave. The light shelf projects beyond the shadow created by the eave and reflect sunlight upward to illuminate the ceiling. This reflected light can contain little heat content and the reflective illumination from the ceiling will typically reduce deep shadows, reducing the need for general illumination.
4- Tubular Day lighting Devices (TDDs) (see fig.3)
|fig (3): Tubular Day lighting Devices|
It uses modern technology to transmit visible light through opaque walls and roofs. The tube itself is a passive component consisting of either a simple reflective interior coating or a light conducting fiber optic bundle. It is frequently capped with a transparent, roof-mounted dome 'light collector' and terminated with a diffuser assembly that admits the daylight into interior spaces and distributes the available light energy evenly.
5- Smart glass (see fig.4)
|fig (4): Smart glass Lighting Technology|
It is the name given to a class of materials and devices that can be switched between a transparent state and a state which is opaque, translucent, reflective, or retro-reflective. The switching is done by applying an electric voltage to the material, or by performing some simple mechanical operation. Windows, skylights, etc., that are made of smart glass can be used to adjust indoor lighting, compensating for changes of the brightness of the light outdoors and of the required brightness indoors.
5- Problems generated from using day lighting source
Two potential problems associated with the use of day lighting buildings are as follows:
1- Glare
Glare occurs when a bright light source such as the sun is in the field of view of users. It can also occur when reflections of the sun are in the field of view.
2- Heat
Daylight is always associated with heat, and the challenge is to maximize the benefit from daylight with minimum heat gain.
all the above information will guide the electrical designer for utilizing the Daylight Source (in cooperation with the architecture engineer) to have the best lighting design which meet the user requirements and in same time increase energy savings in the buildings.
In the next topic, I will explain the artificial lighting sources and loads. So, please keep following. | http://www.electrical-knowhow.com/2012/03/electrical-load-classification-and_10.html |
Global warming and climate change are major challenges facing the nation and the world. More than two thirds of the electric energy and one third of the total energy are used to heat, cool, and operate buildings, representing majority of all CO2 emissions. A reduction in building energy consumption will help to mitigate the energy security and climate change effects on buildings. The reduction in energy consumption is accomplished through the development of new technologies (for the building's envelope, mechanical, and lighting systems) that save energy and reduce CO2 emissions. However, an alternative approach is the use of passive systems that employ renewable energy sources. Passive systems avoid the need for heating or cooling through better design, construction, and operation. They utilize solar or wind energy to heat, cool, or light buildings. This study analyzes the sensitivity of energy demanded to build to code building’s envelops. In other words, investigating whether building that meets the need of enveloping code can take advantage of the weather surrounding the building, in terms of cooling, or heating (comfort) the building as needed. Four high-rise office buildings (glazed curtain wall) with four different aspect ratios (1:1, 1:2, 1:3, and 1:4) are thermally analyzed in four climate zones: cool, temperate, arid, and tropical. The envelope of these high-rise buildings is modeled to meet International Energy Conservation Code (IECC) requirements, which references several American Society of Heating, Refrigeration, and Air Conditioning Engineers (ASHRAE) standards. As a result, the energy performance of high-rise office buildings is not sensitive to the passive solar gain as long as the exterior envelopes are built to IECC 2009 requirements, which does not allow the use of the ambient climate condition of the building to get comfort. This is not appropriate from the concept of sustainability of buildings as referred to above. | http://dspace.elmergib.edu.ly/handle/123456789/55?locale-attribute=ar |
Some Aspects of Soil Thermal Properties (Published)
Globally buildings are responsible for approximately 40% of the total world annual energy consumption. Most of this energy is for the provision of lighting, heating, cooling and air conditioning. An increase in awareness of the environmental impact of CO2, NOx and CFCs emissions triggered a renewed interest in environmentally friendly cooling and heating technologies. Under the 1997 Montreal Protocol, governments agreed to phase out chemicals used as refrigerants that have the potential to destroy stratospheric ozone. It was therefore considered desirable to reduce energy consumption in order to decrease the rate of depletion of world energy reserves as well as the pollution to the environment. One way of reducing building energy consumption is to design buildings, which are more efficient in their use of energy for heating, lighting, cooling and ventilation. Passive measures, particularly natural or hybrid ventilation rather than air-conditioning, can dramatically reduce primary energy consumption. Therefore, promoting innovative renewable energy applications including the ground source energy may contribute to preservation of the ecosystem by reducing emissions at local and global levels. This will also contribute to the amelioration of environmental conditions by replacing conventional fuels with renewable energies that produce no air pollution or the greenhouse gases (GHGs). An approach is needed to integrate renewable energies in a way to achieve high building performance standards. However, because renewable energy sources are stochastic and geographically diffuse, their ability to match demand is determined by the adoption of one of the following two approaches: the utilisation of a capture area greater than that occupied by the community to be supplied, or the reduction of the community’s energy demands to a level commensurate with the locally available renewable resources. Ground source heat pump (GSHP) systems (also referred to as geothermal heat pump systems, earth-energy systems and GeoExchange systems) have received considerable attention in recent decades as an alternative energy source for residential and commercial space heating and cooling applications. The GSHP applications are one of three categories of geothermal energy resources as defined by ASHRAE and include high-temperature (>150°C) for electric power production, intermediate temperature (<150°C) for direct-use applications and GSHP applications (generally (<32°C). The GSHP applications are distinguished from the others by the fact that they operate at relatively low temperatures. | https://www.eajournals.org/keywords/ground-source/ |
This £10.4m office building in Carlisle, is the new headquarter offices for Cumbria County Council, and will form an essential component in the council’s transformation.
The aspiration of the Council was to occupy a building which is sustainable, and integrates passive design, low energy technologies and reduced maintenance requirements. In response the primary focus of the design of the building, and the associated MEP services installations was to maximise natural ventilation, natural day lighting, minimise heat gains within the building and incorporate renewable and low energy technologies in order to reduce energy consumption and the associated production of carbon dioxide.
The building services installations contribute to the overall sustainability of the building by incorporating renewable, low energy systems and sustainable technologies such as;
• Natural/Mixed Mode Ventilation
• Variable Refrigerant Flow simultaneous sheeting & cooling systems to cellular spaces
• Free cooling using outside air
• Night time cooling
• LED lighting technology
• Rainwater harvesting to serve flushing cisterns
• Roof mounted photovoltaics
The mechanical and electrical services are designed to maximise flexibility of the open plan office space and to facilitate the possible future sub division of the office area. | https://www.hannan-uk.com/project_tag/cumbria-county-council/ |
12 C Minimize long duct runs and unnecessary turns to keep static pressure losses to a minimum and, in turn, reduce the fan = s energy consumption. C Include in specifications the requirement of a building commissioning program to ensure good indoor air quality and energy efficiency as outlined in ASHRAE guidelines. C Consider the feasibility of storage systems for chilled and hot water so that off- peak usage of electric power can be utilized where off- peak rates make it advantageous. C Consider renewable sources of heat, such as geothermal. Energy Loads The components, or loads, of the end- uses are those forces that induce the devices or equipment to use energy. For example, heat produced by occupants is a load on the cooling system, an end- use. Designers with a clear understanding of energy use characteristics in educational facilities can select more rewarding strategies by targeting major end- uses and their loads. Targeting HVAC and lighting achieves the highest energy savings, so many ECMs are discussed in terms of their ability to reduce the consumption of these two key end- uses and their associated loads. Selection and design of heating, ventilating, and cooling ( HVAC) systems embodies complex relationships, many of which relate directly to the comfort and well being of occupants. When dealing with humidity control and ventilation, health must always take precedence over energy issues. In addition to the urgency of indoor air quality needs, engineers are faced with a wide variety of options for accomplishing that goal. HVAC Loads Principally, HVAC systems use energy to perform four functions: provide ventilation; supply cool conditioned air; control moisture and provide heated air. The major internally generated loads that contribute to the cooling requirement are heat and moisture generated by occupants, lights, and equipment. Some of these loads can often be effectively reduced. Heat gain from external loads include heat radiated from the sun to interior surfaces through glazing, heat conducted to the interior from exterior surfaces, and infiltration of unconditioned outside air through the building envelope. Outside air introduced as ventilation air also makes a large contribution to the air conditioning load. Air conditioning energy consumption can be reduced by either reducing these loads or selecting more efficient HVAC equipment. The design team has two fundamental methods for achieving low air- conditioning energy consumption: C Minimizing the HVAC loads and the size of the HVAC equipment. C Maximizing the efficiency of the HVAC equipment. | http://digital.ncdcr.gov/cdm/ref/collection/p249901coll22/id/1398/ |
A new $258-million headquarters for Manitoba Hydro is under construction in the centre of Winnipeg. Covering an entire city block on the south side of Portage Avenue between Edmonton and Carlton Stree...
A new $258-million headquarters for Manitoba Hydro is under construction in the centre of Winnipeg. Covering an entire city block on the south side of Portage Avenue between Edmonton and Carlton Streets, the 22-storey building is scheduled to be completed later this year. The building’s 64,600 square metres of space will be home to 1,800 Manitoba Hydro employees, now located in various offices around the city.
Architects Kuwabara Payne McKenna Blumberg designed the form as two glass towers that splay open to the south and are set upon a podium.
Not surprisingly, given that the owner is a power utility, the building is designed to be a model of energy efficiency. The design uses passive techniques and integrates many environmental systems to be 60% more energy efficient than the Model National Energy Code for Buildings. Energy consulting and energy modelling was performed by Transsolar Energietechnik of Stuttgart, Germany. Natural Resources Canada (NRCan) assisted and provided further verification of the energy saving using DOE-2 software.
The mechanical-electrical consulting engineer for the project is Earth Tech (Canada), with Alan Aftanas, P.Eng. in Winnipeg as project manager, John Munroe, P.Eng. in Calgary as chief mechanical engineer, and Mike Shewchuk, P.Eng. in Edmonton as lead electrical engineer.
MECHANICAL & ELECTRICAL DESIGN
Earth Tech (Canada)
An integrated design process modeled on the successful C-2000 program by Natural Resources Canada was adopted for the Manitoba Hydro Head Office project. The full design team met regularly from day one, with all issues — architectural, structural, mechanical and electrical — on the table for discussion. Passive techniques are maximized in the building and all members of the design team approached their designs with this philosophy in mind.
The extreme Winnipeg climate presented challenges. The building has a winter design temperature of –35C and 10,620 heating degree-days per year.1
Double facade and opening windows
The building has a double facade which provides a superior buffer between the outdoors and the indoors. The interior glass is located approximately 1 metre inside the outer facade. Natural ventilation is permitted under the correct weather conditions. Vents in the exterior facade automatically open with actuators, while the building mechanical ventilation systems are shut down. The occupants will be signalled by the internal computer network that the building is in natural ventilation mode, and are free to open windows located on the interior facade at their own discretion. If they want more fresh air they simply open their windows. In addition, under the right solar conditions, some preheating will take place in the double facade buffer zone, which will extend the season for natural ventilation.
Concrete mass helps to stabilize temperatures
Low intensity thermo-active concrete ceilings heat and cool the building by circulating heated or cooled water in plastic tubes embedded in the concrete. The system allows the thermal mass of the concrete to stabilize the building temperature. By having only minor temperature swings from day to night, the building uses less energy and the size of the heating/cooling plant could be reduced.
Since the human body not only feels air temperature, but also the temperature of surrounding surfaces, the radiant heating will provide superior comfort. The radiant slab system is also more energy efficient than a traditional air system due to the better thermal properties of water compared to air.
When it is -35C outdoors on frosty Winnipeg winter days, the space between the outer facade and the inner facade will be heated and the occupants will never be exposed to the cold exterior glass surfaces.
Atria as lungs
The building has north and south atria called “winter gardens.” Each of the south atria is six storeys high and each of the north atria is three storeys high. They are stacked in modules, one on top of the other, reaching 18 storeys of the building. The south atria are the “lungs” of the building and absorb solar radiation for preheating the air in the winter.
In winter, 100% fresh air is filtered and preheated to 10C before entering the atria. Waterfalls in the atria provide humidification; for humidifying the water is warmed, and for dehumidifying the water is chilled. The atria in turn provide pre-warmed, pre-filtered, humidified/dehumidified air into the individual floors. In summer, exterior windows at the bottom and the top of the atria are opened to remove heat from the space.
100% fresh air through raised flooring
By de-coupling the heating/cooling function from the ventilation systems, we were able to provide 100% fresh air in a once-through ventilation system located in a raised floor. Typical North American buildings recirculate about 80% of their air.
The raised flooring serves as a plenum for the pressurized fresh air, which is distributed by displacement ventilation. It is introduced at a low velocity at the floor level and rises into the breathing zone through convection currents created by heated objects e.g. occupants, computers, etc. Contaminants expelled by the occupants (carbon dioxide, germs, etc.) are exhausted at ceiling level directly to the outdoors via the solar chimney.
The raised flooring system also allows for plug-in electrical and communication system networks that are easy to access and modify.
Solar chimney exhausts air
The building has a large solar chimney, 12 metres long by 1.8 metres wide, at the north end of the building. Extending 26 metres above the top of the office tower, the concrete is replaced by glass construction above the roof line to assist in creating a negative pressure in the building. The solar chimney will power air movement in the building without the use of fans. A solar absorber (a heat retaining thermal mass constructed using phase change materials) will assist the solar chimney operation later in the day, after the sun has set.
In winter, the solar chimney serves as a large duct to collect exhaust air from the occupied zones and uses it to heat the parking garage below the building.
Geothermal field extends a city block
The building uses a geothermal heating and cooling system. Heat extracted from the building during the summer months is stored in the earth for use in the winter.
The geothermal earth heat exchanger extends for the entire city block and deep into the bedrock below the building and the parking structure. The exchanger is possibly the first of its kind of this size completely located under a structure. It consists of 280 boreholes on a 4.5-m grid throughout the 7,500 sq.m site. The boreholes are drilled to a depth of 116 metres. A plastic tube filled with a thermally enhanced grout to enable an effective heat exchange is looped in each borehole to exchange energy with the earth.
Installing the geothermal field below the building presented challenges to ensure that the boreholes would not affect the foundation system. The installation took six months over the winter months when conditions are difficult and drilling is a wet, messy process.
Supplementing the geothermal plant are high efficiency natural gas condensing boilers, chillers and cooling towers.
Responding to the weather
A central building management system will coordinate all the building functions. In addition to controlling the HVAC system, it will monitor and control various stand-alone systems such as the blinds, lighting, security system, fire and windows on the exterior facade.
The slab temperatures are controlled with sensors embedded in the concrete.
Unique features of the building controls are:
* A weather station mounted on a mast on the top of the building will monitor outdoor climatic conditions including day
light intensity, wind speed and direction, as well as temperature and humidity.
* Vents on the exterior facades will automatically open and close with actuators when outdoor temperatures and conditions are suitable for natural ventilation.
* The vents will close when the winds are too strong, when it is raining, or when temperature or solar gains are not suitable for natural ventilation.
* The temperature in between the outer facade and the inner facade is monitored. If excessive heat builds up in this space it will be relieved to the outdoors by opening the vents.
* The blinds between the inner facade and the outer facade are automated, and open or close based on factors like the intensity of the sunlight and the desire to shed solar gain. Each blind has a motor to raise it, lower it, or adjust the angle of the blades. The upper blades are maintained horizontal to bounce daylight onto the ceiling. The occupants will also be able to override the automated controls.
Daylighting and artificial light
The lighting systems have their own integral lighting level and motion sensors. Daylighting is a big part of the building design. For example, the floor plates are much slimmer, and the floor to ceiling heights are higher than typical to optimize daylight penetration into the spaces. The users should be able to rely on natural light about 80% of the time.
For the general office lighting, luminaires are suspended from the exposed concrete ceilings with approximately 70% up-lighting to reflect the light off the ceiling. Light fixtures will be T5 high output fixtures with integral sensors.
LED sources have been adopted throughout to both enhance energy efficiency as well as to promote the client’s commitment to sustainability. | https://www.canadianconsultingengineer.com/features/manitoba-hydro-head-office/ |
With the aim to limit the number of ineffective designs, this dissertation has investigated the impact of architectural design strategies on improving the energy performance of and thermal comfort in high-rise office buildings in temperate, sub-tropical and tropical climates. As the starting-point of this research, a comparative study between twelve high-rise office buildings in three climate groups was conducted. For each climate group, three sustainable high-rises were selected and one typical high-rise design as a reference. The effectiveness of architectural design strategies was compared between the two categories of buildings (high-performance versus low-performance) concerning their potential impact on heating, cooling, lighting and ventilation loads. Certain architectural design strategies were found to be major determinants of energy performance in high-rise buildings. These can be classified under the categories of geometric factors, envelope strategies, natural ventilation strategies, and greenery systems. To quantify the extent to which these architectural design strategies affect energy use and thermal comfort of tall office buildings, simulation studies were carried out.
To quantify the impact of geometric factors on the energy efficiency of high-rise office buildings, performance-based simulations were carried out for 12 plan shapes, 7 plan depths, 4 building orientations and discrete values for the window-to-wall ratio (WWR). The results of the total annual energy consumption (and different energy end-uses) were used to define the most and least efficient solutions. The optimal design solution is the one that minimises, on an annual basis, the sum of the energy use for heating, cooling, electric lighting and fans. The percentile difference - a deviation in the total energy use - between the most and least efficient design options showed the extent to which geometric factors can affect the energy use of the building. It was found that geometric factors could influence the energy use up to 32%. Furthermore, the recommended design options were classified according to their degree of energy performance for each of the climates.
The second group of strategies is related to the envelope design. To quantify their degree of influence, an existing tall office building was selected as a typical high-rise design for each of the climates and the energy use prior and after refurbishment was compared through computer simulations with DesignBuilder. The 21-storey EWI building in Delft, the Netherlands, is selected as the representative for the temperate climate and the 65-storey KOMTAR tower in George Town, Malaysia, for the tropical climate. As part of a sensitivity analysis, energy performance simulations defined façade parameters with higher impact on building energy consumption. A large number of computer simulations were run to evaluate the energy-saving potential of various envelope measures, as well as their combinations. The results showed which set of envelope measures suits each climate type best. Furthermore, it was found that the right combination of envelope strategies could reduce the total energy use of a conventional tall office building by around 42% in temperate climates and around 36% in tropical climates.
One other important difference between conventional and sustainable tall buildings is related to the application of natural ventilation. In this regard, the potential use of different natural ventilation strategies to reduce the energy demand for cooling and mechanical ventilation in high-rise buildings was investigated by using the same validated base models. The results showed that for a naturally ventilated tall office building in the temperate climate on average only 4% of the occupancy hours a supplementary air-conditioning system might be needed for providing thermal comfort during summer. For the tropical climate, the average percentage of discomfort hours (when air-conditioning is required to keep the indoor air temperature within the comfort limits) was around 16% of the occupancy hours during one year. In both climates, natural ventilation strategies could meet the minimum fresh air requirements needed for an office space for almost the entire period of occupancy hours; 96% in temperate climates and 98% in tropical climates.
The last important strategy that is becoming an integrated part of sustainable tall buildings is the use of greenery systems. The effects of greenery systems on the energy-efficiency, thermal comfort and indoor air quality of buildings were investigated by conducting a thorough literature review on five greenery concepts, including the green roof (GR), green wall (GW), green balcony (GB), sky garden (SG) and indoor sky garden (ISG). It was found that greenery systems have a limited impact for reducing the energy use of high-performance buildings. The maximum efficiency of greenery systems was reported during summer and for places with higher solar radiation and when integrated into buildings that have no solar control systems. However, other large-scale benefits for the urban environment (mitigation of CO2 concentration) and building residents (increased productivity and higher well-being) could justify the application of greenery systems as an essential sustainability feature for the design of tall office buildings.
To sum up, the architectural design is a determinant contributor to the performance of buildings and the comfort of occupants. The findings of this research were used to point out climate specific design strategies for tall office buildings in temperate and tropical climates. At the end of dissertation, a proposed model of an energy-efficient and comfortable high-rise office building for each of the investigated climates was illustrated. It is expected that the discussions and recommendations provided in this dissertation could form an acceptable starting point for improvements to tall building design and could be of assistance to make energy-wise decisions during the design process.
This work is licensed under a Creative Commons Attribution 4.0 International License. | https://books.bk.tudelft.nl/press/catalog/book/isbn.9789463660693 |
Payette Associates, Inc.
|Structural Engineer
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Lim Consultants, Inc.
|Construction Manager
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Gilbane, Inc.
|Timeline
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September 2006 - January 2009
The $114.5 million, 188,000 S.F. Integrated Sciences Building (ISB) combines the Life, Chemical, and Physical Sciences into one building to inspire new models of interdisciplinary teaching and research. The ISB contains laboratories, a 300-seat auditorium, 80-seat stepped classroom, computer resource center, and faculty offices. A four story atrium serves as a central collaborative space for students, and connects the ISB to the adjacent Life Sciences Laboratories building.
Research spaces, modular laboratories, and common areas are all designed to foster synergy between students, professors, and research faculty from different departments across the sciences. Introductory and advanced laboratories are collocated to promote interactions between lower and upper class students. By dissolving the boundaries which traditionally separated sciences, the ISB paves the way for new forms of science to emerge in the 21st century.
Together, the building provides a flexible framework which adapts to changing needs over time. While not LEED Certified, the building contains a variety of sustainable features to maximize energy efficiency and reduce environmental impacts.
SUSTAINABLE FEATURES
Sustainable Sites
- A compact building footprint and strategic site location maximize open green space. Together, the ISB and adjacent Life Sciences Laboratories frame a large exterior courtyard, which acts as a natural extension of the historic Stockbridge Road.
- An “intensive” rooftop garden installed over the chiller plant contains soil depths of 6-42” and accommodates a wide variety of plants, shrubs, and small trees. A second, “extensive” garden with a soil depth of 6” is planted over the loading dock and supports native, drought-tolerant species.
- Bicycle racks are located at the east and west building main entrances. Dedicated shower and changing facilities are provided on the first floor of the building to encourage reduced dependency on motorized vehicle transport.
Water Efficiency
- A 20,000 gallon storage tank collects rainwater on the roof to reduce discharge into the campus sewer system. The rooftop chiller system reuses rainwater collected onsite, saving an estimated 250,000 gallons of water annually. Effluent water is piped from the Amherst water treatment plant to supplement water lost to evaporation.
Energy & Atmosphere
- The building’s massing is oriented for optimal passive solar. Terracotta “baguette” exterior louvered shading devices on the atrium’s south-facing curtain wall allow for ample natural daylight infiltration, whilst protecting the building from glare and solar heat gain. Windows are insulated and treated with a low emissivity coating to further reduce heating and cooling losses.
- Two high efficiency water cooled electric centrifugal chillers and one steam absorption chiller were installed in the regional chiller plant as part of the project. The electric chillers utilize variable speed fan drive (VFD) to operate more efficiently depending on user demand. A plate and frame heat exchanger eliminates the need for chillers during the winter, when cooling loads are very low. Using a combination of steam and electric chillers helps the campus to balance steam and electric consumption, and maximizes operating efficiency at the Central Heating Plant.
- Occupancy sensors, thermostats, and multi-level light switches are installed in offices, laboratories, and other spaces to provide advanced control for users. Occupancy sensors detect motion and natural daylight levels, then automatically adjust artificial lighting accordingly.
Materials & Resources
- UMass Amherst saved and recycled 100% of structural concrete and steel from the WWII era Marshall Annex Building, which was demolished to construct the ISB.
- Building materials and finishes were selected for their sustainable properties, recycled content, and low environmental impacts. Interior finishes include bamboo wood in common areas, rubber flooring in laboratories, and vinyl ceramic tiles installed in high-traffic circulation spaces.
Indoor Environmental Air Quality
- A heat recovery wheel is installed to maximize heating and ventilation efficiency. The system captures heat energy from the classroom wing’s exhaust air stream and uses it to condition incoming supply air serving the lab spaces. This exhaust air stream is used to preheat cold, incoming fresh air that serves the lab areas. In addition to these energy-saving measures, enthalpy heat recovery wheels remove latent heat from the air during the summer, and add heat and moisture in the winter. This advanced system recovers up to 50% more heat and moisture compared to the conventional glycol loop HVAC systems used in laboratory buildings.
- Low flow fume hoods rated at 60 cubic feet per minute (CFM) are installed in teaching laboratories. This helps to reduce heating, cooling, and fan energy consumption compared to standard models rated at 100 CFM. Traditional, 100 CFM hoods are used for dispensing waste fumes only.
- Perimeter laboratories and offices utilize hot water radiant ceiling panels for heating, while maintaining airflow rates when unoccupied.
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West Exterior Perspective
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Site Plan
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Atrium Exploded Axonometric
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Interior Atrium
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Atrium Interior
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Northeast Exterior Perspective
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North Exterior Perspective
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Classroom
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East Exterior Perspective
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Laboratory
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HVAC Diagram
All images by Warren Jagger Photography, courtesy of Payette Associates, Inc. Web page design by Ryan Rendano.
RESOURCES
Videos
Integrated Sciences Building Dedication - 09/14/2009
'Science for Everyone' at Homecoming
Articles
- Donation Helps Along New Science Building - The Massachusetts Daily Collegian
- UMass Amherst Breaks Ground for $92.7 Million Integrated Sciences Building - UMass Amherst News & Media Relations
- New Building to Integrate Science Education at UMass - The Massachusetts Daily Collegian
- Integrated Sciences Building Opens for Classes - The Massachusetts Daily Collegian
- UMass Dedicates New $114.5 Million Integrated Sciences Building - MassLive
- Integrated Science Building Dedicated - UMass Amherst News & Media Relations
- Integrated Sciences Building Officially Dedicated - The Massachusetts Daily Collegian
- Shedding Light on the Sciences at UMass Amherst - Laboratory Design News
- UMass Amherst Campus Earns 'A' Grades on National Sustainability Report Card
- UMass Amherst Integrated Science Building / Payette - ArchDaily
- Integrated Sciences Building - The UMass Amherst College of Natural Sciences
- University of Massachusetts, Amherst Integrated Sciences Building - Payette Associates, Inc.
- Integrated Science Building University of Massachusetts Amherst - Learning Spaces Collaboratory
- Integrated Science Building (UMass Amherst) - An Engineer's Guide to Western Mass
Follow UMass Campus Planning on Facebook, Twitter, and WordPress for the latest news and events! | https://www.umass.edu/cp/integrated-sciences-building |
# Vale Living with Lakes Centre
The Vale Living with Lakes Centre is a research center for The Cooperative Freshwater Ecology Unit in Sudbury, Ontario, Canada. The centre consists of 2 buildings totalling 2,643m² (28,441 sq ft). The 2 storey main building (2,125m² / 22,865 sq ft) contains offices, laboratories, and teaching/meeting spaces. The second building also known as the Watershed Centre (518m² / 5,576 sq ft) contains field crew operations, storage, and specialized facilities.
The Vale Living with Lakes Centre was designed by Peter Busby of Busby, Perkins + Will in collaboration with Jeff Laberge from J.L. Richards and Associates who provided engineering and architectural services. The scientists and clients of the Living with Lakes Centre wanted the project to improve the site through the construction of the centre. Therefore, by designing with sustainable landscaping strategies and the design of stormwater management systems, the water leaves the site cleaner than when it entered ensuring the Living with Lakes Centre does not harm the waters of Lake Ramsey through its operation.
The design team worked in collaboration with the scientists that would later occupy the building to optimize the architectural conditions to their standards to produce the Living with Lakes Centre. This integrated design process required the equal input of people with engineering specialties, design specialties, and ecosystem regeneration specialties to benefit the project as a whole. During the design process the integrated group had two concepts that drove the project: good architecture equals good engineering and no one knows more than everyone. These concepts provide insight into the thought process through the design and build of the Vale Living with Lakes Centre which reiterates the importance of an integrated design approach.
## History
The city of Sudbury has a history of nickel and copper mining which resulted in environmental damage, including the clear-cutting of forests and acid rain. Due to this mining history the vegetation in the region was damaged, and new vegetation could not grow in the acidic soil, resulting in the fauna in the area also being negatively impacted. Also, the lakes and water systems in the area became acidified resulting in a drastic loss of biodiversity in the Sudbury area.
In the late 1970s, the City of Sudbury started regreening efforts in the city to remediate the damaged landscape through the human intervention of distributing lime across the barren landscape to balance the acidic soil to allow vegetation to grow once again. The acidification of lakes in the area due to acid rain resulted in a lack of biology making it an obvious choice for the research of lake remediation. Thus resulting in the Vale Living with Lakes Centre which houses the Cooperative Freshwater Ecology Unit.
The Cooperative Freshwater Ecology Unit was in need of a new office space for research after the old 1940’s cabins they used for research became too run down. This group researches stressors that can affect the health of water-based ecosystems in the North which includes climate change, invasive species, and loss of biodiversity, making Ramsey Lake in Sudbury a great location for research.
## Sustainability
The Vale Living with Lakes Centre was certified LEED platinum in 2014 and received an OAA Sustainable Design Excellence Award in 2015. The building uses locally sourced materials including Jack Pine glulam beams from Chapleau, limestone for cladding and landscaping, and white cedar cladding from Manitoulin Island. Wood was the primary building material for the center including engineered wood beams for the primary structure, and wood panelling for the lateral structure. Thus resulting in a Green Building Wood Design Award from Wood Works! in 2012.
The centre's design for energy preservation and the use of sustainable energy sources derived from the idea that the facility would reduce the operating costs of the building to save the funding for research. The Living with Lakes Centre uses an on-site geothermal heating and cooling system consisting of 40 geothermal wells that feed 3 heat exchangers that connect to the radiant in-floor heating system to provide sustainable heating and cooling for the centre. This sustainable energy source saves money from operating costs and provides renewable heating and cooling without carbon emissions. Natural daylighting and ventilation strategies were also designed and implemented in the Living with Lakes building to reduce the energy requirements from artificial lighting and fans. The buildings south-facing orientation and the placement of windows result in a naturally well-lit building. The use of exterior solar shading fins allows the sun to naturally light the building without overheating the interior during warm months. The angling of the shading fins act to reflect light to minimize unwanted heat gains, reducing cooling requirements during warm months. The Living with Lakes Centre also uses a super-insulated envelope to reduce thermal losses, which minimizes the amount of heating and cooling required.
There are green roofs on both of the Living with Lakes Centre buildings which reduce water runoff to minimize the chance of flooding during extreme weather events. The vegetation provides added roof insulation to minimize heating requirements, and it is planted with blueberries which provide habitat and food for native bird species of the Sudbury area.
An important element of the Vale Living with Lakes Centre is the sustainable landscape strategies that act to preserve and improve the shoreline of Ramsey Lake so as not to further worsen the existing conditions. Stormwater management strategies are designed to filter and treat water runoff on-site to avoid contaminated water from running into Ramsey Lake, Sudbury’s water reservoir. Permeable paving was used in the parking area which acts to divert stormwater to the on-site bioswales that uses vegetation to filter the water and directs the runoff into a pond on-site that acts as a water reservoir which further filters and treats the stormwater runoff using native plant species that naturally treat contaminants. Water from the pond reservoir is then recycled and used as greywater for flushing toilets, and cleaning equipment, thus reducing potable water consumption. Limestone was chosen as a primary landscaping material to gradually improve the acidic Ramsey Lake through the limestone’s ability to reduce acidity over time.
## Awards
2008 Holcim Award for Sustainable Construction, Bronze Award 2012 Wood Works! Green Building Wood Design Award 2012 Canadian Consulting Engineering Awards 2014 LEED Platinum Certified- LEED Canada for New Construction and Major Renovations 2015 OAA Design Excellence Award 2015 OAA Sustainable Design Excellence Award | https://en.wikipedia.org/wiki/Vale_Living_with_Lakes_Centre |
September 27, 2011 - The University of British Columbia recently celebrated the opening of its new Faculty of Law at Allard Hall. Designed by Diamond and Schmitt Architects (in joint venture with CEI Architecture Planning Interiors of Vancouver), the facility is targeting LEED Gold designation for energy efficiency.
September 27, 2011 By Anthony Capkun
Design features include a ground-source heating/cooling system with 160 wells that, says Diamond and Schmitt, will reduce the greenhouse gas footprint of the building by 87% compared to a conventional gas-fired system. Further efficiencies are gained through the use of passive cooling strategies (overhangs, exterior shades, thermal mass), displacement ventilation, high-efficiency lighting, and a robust, well-insulated building envelope.
The $65-million, 141,000-sf building features a range of flexible learning and study spaces, and provides space for more than 50 faculty members, 600 undergraduate and 100 post-graduate students. | https://www.energy-manager.ca/ubc-faculty-of-law-at-allard-hall-targeting-leed-gold-for-energy-efficiency-1082/ |
1 What are the Mayan Ruins?
2 Where are the Mayan Ruins?
3 What are the Cancun Ruins?
4 What are the Mayan Ruins of Belize?
5 What are the Mayan Ruins of Tulum?
6 What are the Chichen Itza Ruins?
7 What are the Coba Mayan Ruins?
8 What are the Best and Most Important Mayan Ruins?
9 Do The Mayan Ruins Still Exist?
10 Where can I see the Mayan Ruins Today?
What are the Mayan Ruins?
Mayan civilisation was extended over three thousand years and is generally considered the longest lasting and the most magnificent civilisation of the Mesoamerican region. Its peak came during what is known as the Classic Period of the civilisation from 250AD to 900AD. During this period, the Mayans built grand architecture in the form of temples, palaces, pyramids, and other kinds of buildings. However, after 900AD, the Mayan civilisation collapsed almost abruptly for which the archaeologists suggest various reasons. The Mayan ruins are the remains of this bygone civilisation and its city states that were once thriving urban centres.
Where are the Mayan Ruins?
The Mayan ruins are located throughout the Mesoamerican region, extending into several countries of Central America. The present-day countries where Mayan ruins are abundantly found include Guatemala, Belize, and parts of Honduras and El Salvador. Further, some Mayan ruins are also found in southeastern states of Mexico from the Isthmus of Tehuantepec eastwards. This also includes the entire Yucatán Peninsula. While this entire region was included in the Mayan civilisation, it was not bound into a unified empire and instead consisted of independent city states which were often at war with each other.
What are the Cancun Ruins?
The city of Cancun is southeastern Mexico is an important site of Mayan ruins. The ruins here are, however, not as extensive as some other sites in the region. The most substantial site of Mayan ruins in the region is El Menco which is located on the mainland just outside the city limits on the road north to Punta Sam. The Cancun ruins are mainly located outside the main city. The name Cancun first appeared in the 18th century maps and it is not clear whether it has Maya origins. According to some colonial sources, the place was known to its Mayan inhabitants as Nizuc.
What are the Mayan Ruins of Belize?
Belize has a variety of well documented and important Mayan ruins and archaeological sites. The area of Belize was part of southern Maya lowlands which particularly flourished during the Classic Period. For instance, one of the most important sites of Mayan ruins in Belize is Caracol, located in western Belize near the border of Guatemala. This was one of the largest Mayan urban centres and today consists of thousands of ancient structures. This was also one of those cities that defeated Tikal, arguably the most powerful Mayan city during the Classic Period. Other Mayan ruins in Belize include Cerros, Lamanai, Altun Ha, Cuello, La Milpa, and others.
What are the Mayan Ruins of Tulum?
One of the most important sites of Mayan ruins is Tulum which served as a major port for Mayan urban centre, Coba. The ruins are located along the east coast of the Yucatan Peninsula on the Caribbean Sea. The site was a thriving port during the Post-Classic Period of Mayan civilisation and reached its height between the 13th and 15th centuries. It even managed to survive for over 70 years after the Spanish occupation of Mexico. Some important architectural sites of this place include Pyramid El Castillo, God of Winds Temple, Temple of the Frescos, and others.
What are the Chichen Itza Ruins?
Among the largest sites of Mayan ruins, Chichen Itza is particularly noteworthy. Chichen Itza is located in the Yucatan State of Mexico and was among the latest urban centres of the Mayans during the Late Classic, Terminal Classic, and even early Post-Classic Period. Other than being one of the largest cities, it was also one of those cities which had a very diverse population. Some of the most important Mayan ruins on this site include the Temple of Kukulkan also known as El Castillo, The Great Ball Court, The Skull Platform, The Platform of Venus, The Temple of the Tables, and others.
What are the Coba Mayan Ruins?
Coba is a large site of ancient Mayan ruins located in the state of Quintana Roo of Mexico. According to the archaeological evidence, the city was founded between 100BC and 100AD and for a while remained a small town with wooden buildings. Population grew stronger after 100AD and eventually it became an important urban centre. It reached its peak between 200AD and 600AD, during which it is estimated to have a population of over 50,000 inhabitants, but also continued to be an important city for a long time after that. This site of Mayan ruins contains several large temple pyramids the tallest of which is 42 meters high.
What are the Best and Most Important Mayan Ruins?
There are many important Mayan ruins located all over the Mesoamerican region. One of the best and most important Mayan ruins is the Tikal National Park in Guatemala which has been declared the UNESCO Heritage of Humanity. Tikal was probably the most important city state of Mayan civilisation during the Classic Period and had a population of over 90,000 inhabitants at its peak. It was founded by the Tikal dynasty in 1st century AD. The site has a variety of architectural structures including palaces, pyramids, causeways, burials, and others. Another very important site of Mayan ruins in Copan located in Honduras and housing a number of well preserved temples, palaces, and very detailed stone sculptures.
Do The Mayan Ruins Still Exist?
A lot of Mayan ruins still exist, particularly those that were once the thriving urban centres of Mayan civilisation. This includes the ruins of Tikal, Chichen Itza, Coban, and other cities. Some of the structures on these Mayan ruins are in a remarkably well preserved form and continue to attract millions of tourists from all over the world every year. This includes a variety of temples, pyramids, palaces, and Mayan sculpture.
Where can I see the Mayan Ruins Today?
Mayan ruins are scattered all over the Mesoamerican region which today incorporates various countries of Central America. The ruins can be seen on a variety of sites in countries such as Guatemala and Belize as well as southeastern Mexico and western portions of Honduras and El Salvador. This region was the site of the Mayan civilisation, particularly during the Classic Period which was the peak of the Mayan civilisation during which various urban centres thrived at this location. | http://mayansandtikal.com/mayan-ruins/mayan-ruins-question-and-answers/ |
300 B.C.
Mesoamerican peoples built pyramids from around 1000 B.C. up until the time of the Spanish conquest in the early 16th century.
Tulum was one of the last cities built and inhabited by the Maya ; it was at its height between the 13th and 15th centuries and managed to survive about 70 years after the Spanish began occupying Mexico. Tulum .
|Tulum Tulu’um Zama|
|State||Quintana Roo|
|Municipality||Tulum|
|Earliest inscription||AD 564|
|Constructed||1200 and 1450|
Scattered deep within the jungles, atop steep hills and within historic caves are some of Belize’s top-rated attractions: Mayan ruins. The archeological sites have stood in these very places since the Maya civilization’s dominance over much of Mesoamerica, between 2,000 and 3,000 years ago.
The Pyramid of Djoser
Yucatec Maya
Tikal Temple IV
Aguada Fénix
Chichen Itza
Major ruin sites such as Chichen Itza , Tulum and Tikal do have security, are open only to those who have payed the fee and are nowhere near as dangerous as some of the large cities, but wise visitors still take simple precautions to reduce the chance of theft spoiling their trip.
You can jump in the water at Tulum ruins and swim north to Boca Paila. Even if you are just going to visit the ruins it is still quite an experience to swim out on the ruins beach and see the ruins from the water. On a hot summer day it is a great way to cool off.
There is not any protection from rain while walking around. It is usually hot walking around, so comfortable clothes , shoes, sunscreen, hat, glasses and water are all good things to keep in mind. If you drive to the ruins , there are many gift shops by the entrance.
Top 15 Mayan Ruins & Archeological Sites To Visit In Mexico Chichen Itza Mayan Ruins. Coastal Ruins Of Tulum . Maya Ruins Of Coba . Palenque . Calakmul Mayan Ruins. Monte Alban. Teotihuacan. Ek Balam .
Mysterious Decline of the Maya From the late eighth through the end of the ninth century, something unknown happened to shake the Maya civilization to its foundations. One by one, the Classic cities in the southern lowlands were abandoned, and by A.D. 900, Maya civilization in that region had collapsed.
Chichen Itza Entrace Fee The entrance fee at Chichen Itza is: $481 Pesos per adult, Kids under 13 years are admitted free. The entrance fee to the site is divided into two amounts, one being the state (culture) and the second being the federal (INAH). The fees are paid at two separate windows. | https://www.mundomayafoundation.org/mayan/how-old-are-the-mayan-ruins.html |
Mesoamerican pyramids, pyramid-shaped structures, are an important part of ancient Mesoamerican architecture. These structures were usually step pyramids with temples on top – more akin to the ziggurats of Mesopotamia than to the pyramids of Ancient Egypt. The Mesoamerican region's largest pyramid by volume – indeed, the largest in the world by volume – is the Great Pyramid of Cholula, in the Mexican state of Puebla.
Contents
Aztecs
The Aztecs, a people with a rich mythology and cultural heritage, dominated central Mexico in the 14th, 15th and 16th centuries. Their capital was Tenochtitlan on the shore of Lake Texcoco – the site of modern-day Mexico City. They were related to the preceding cultures in the basin of Mexico such as the culture of Teotihuacan whose building style they adopted and adapted.
- Malinalco
- Templo Mayor
Maya
The Maya are a people of southern Mexico and northern Central America (Guatemala, Belize, western Honduras, and extreme northern El Salvador) with some 3,000 years of history. Archaeological evidence shows the Maya started to build ceremonial architecture approximately 3,000 years ago. The earliest monuments consisted of simple burial mounds, the precursors to the spectacular stepped pyramids from the Terminal Pre-classic period and beyond. These pyramids relied on intricate carved stone in order to create a stair-stepped design. Many of these structures featured a top platform upon which a smaller dedicatory building was constructed, associated with a particular Maya deity. Maya pyramid-like structures were also erected to serve as a place of interment for powerful rulers. Maya pyramidal structures occur in a great variety of forms and functions, bounded by regional and periodical differences.
- Altun Ha
- Calakmul
- Caracol
- Comalcalco
- Copan
- Chichen Itza
- El Mirador
- La Danta temple, is also the name of the largest Maya temple. The temple reaches 79 metres (259 ft) high, and with a volume of 2,800,000 cubic meters, it is one of the largest pyramids in the world.
- El Tigre
- Los Monos
- Lamanai
- Palenque: Temple of the Inscriptions
- Tikal: Tikal Temple I; Tikal Temple II; Tikal Temple III; Tikal Temple IV; Tikal Temple V; Lost World Pyramid; Talud-Tablero Temple
- Uxmal
Tarascans
The Tarascan state was a precolumbian culture located in the modern day Mexican state of Michoacán. The region is currently inhabited by the modern descendants of the P'urhépecha. Tarascan architecture is noted for "T"-shaped step pyramids known as yácatas.
Teotihuacan
The Teotihuacan civilization, which flourished from around 300 BCE to 500 CE, at its greatest extent included most of Mesoamerica. Teotihuacano culture collapsed around 550 and was followed by several large city-states such as Xochicalco (whose inhabitants were probably of Matlatzinca ethnicity), Cholula (whose inhabitants were probably Oto-Manguean), and later the ceremonial site of Tula (which has traditionally been claimed to have been built by Toltecs but which now is thought to have been founded by the Huastec culture).
- El Castillo & High Priest's Temple in Chichen Itza
- Pyramids of the Sun, the Moon and Temple of the Feathered Serpent in Teotihuacan
- Xochicalco
- Tula
- Talud-tablero
Classic Veracruz
The best known Classic Veracruz pyramid, the Pyramid of Niches in El Tajín, is smaller than those of their neighbours and successors but more intricate.
Zapotecs
The Zapotecs were one of the earliest Mesoamerican cultures and held sway over the Valley of Oaxaca region from the early first millennium BCE to about the 14th century.
Others
The following sites are from northern Mesoamerica, built by cultures whose ethnic affiliations are unknown:
Altavista
This astronomical and ceremonial center was the product of the Chalchihuite culture. Its occupation and development had a period of approximately 800 years (ca. 200—1000). This zone is considered an important archaeological center because of the astonishing, accurate functions of the edifications. The ones that stand out the most are: The Moon Plaza, The Votive Pyramid, the Ladder of Gamio and The labyrinth. In The Labyrinth you can appreciate with precision and accuracy, the respective equinoxes and the seasons. | http://community.worldheritage.org/articles/eng/Mesoamerican_pyramid |
Amazing Historical Structures : Have you ever been in awe of a structure that left you in complete wonder? Ancient buildings and monuments are some of the most fascinating feats of human engineering and creativity. From the iconic Taj Mahal to the mysterious Stonehenge, these incredible structures have stood the test of time and still captivate people today. Here are 9 amazing historical structures that will take your breath away.
Amazing Historical Structures
1. Taj Mahal
The Taj Mahal is one of the most famous buildings in the world. Built by Mughal Emperor Shah Jahan in Agra, India, as a mausoleum for his wife Mumtaz Mahal, this architectural wonder is famous for its stunning marble domes and intricate design. The Taj Mahal is the most photographed building in the world, and is an iconic example of Indian architecture. It is also one of the “New Seven Wonders of the World”, after a poll where people voted for the greatest architecture in the world.
2. Parthenon
The Parthenon is one of the most famous temples in the world. Located in the heart of Athens, Greece, the Parthenon was built in the 5th century BC as a temple to the goddess Athena. It is considered one of the most important examples of Ancient Greek architecture, and the architectural style of the Parthenon has strongly influenced Western architecture for over 2000 years.
3. Great Wall Of China
The Great Wall of China is one of the most famous wonders of the world. What began as a series of defensive walls built in the 6th century BC, the Great Wall is now a UNESCO World Heritage site. The sections of the wall that stand today are a mix of many different walls built in different eras. The largest and most famous section of the wall is located in the northern part of China. The Great Wall of China is the longest man-made structure in the world, and is believed to be the second most visited tourist destination in the world.
4. Hagia Sophia
Hagia Sophia is a former Greek Orthodox church that is now a museum in Istanbul, Turkey. It is widely considered to be one of the greatest architectural achievements in human history, and was the world’s largest cathedral for nearly 1000 years. It was built in the 6th century as a Byzantine imperial cathedral, and was later converted into a mosque after the Ottoman conquest of Istanbul in the 1450s. It was converted into a museum in 1935, and is now a UNESCO World Heritage site.
5. Stonehenge
Stonehenge is a set of mysterious standing stones located in Wiltshire, England. No one knows for certain how this ancient site was built, or what it was used for. Dating back to the Neolithic period (4000-2000 BC), Stonehenge was built as a setting of large stones placed in a circular pattern, surrounded by a large earth mound. The site has been studied by archaeologists for many years, but it still remains a mystery as to why and how Stonehenge was built.
6. Angkor Wat
Angkor Wat is a renowned temple complex located in Cambodia. Built in the 12th century as a Buddhist temple, Angkor Wat is considered one of the most important architectural achievements of Southeast Asia. The temple is famous for its beautiful design and extensive use of certain architectural elements, such as the Khmer roof and the intricate carvings on its walls. Angkor Wat was named a World Heritage site by UNESCO in 1992, and is one of the most visited tourist destinations in the world.
7. Chichen Itza
Chichen Itza is a pre-Columbian Maya city located in the Mexican state of Yucatan. This archaeological site is famous for its architectural significance and design. Chichen Itza is one of the largest Mayan cities, and hosts many temples and pyramids as well as other architectural feats. Many of these buildings have astronomical significance, and some have been astronomically aligned so that they would cast shadows on certain dates.
8. Colosseum
The Colosseum is Rome’s most famous attraction. Originally used as a giant arena where gladiator fights and other forms of entertainment took place, the Colosseum is the largest Roman amphitheatre ever built. The Colosseum was built in the 1st century AD, and is the largest Roman public structure in the world.
9. Pyramids Of Giza
The Pyramids of Giza are three ancient Egyptian pyramids located near Cairo. The pyramids of Giza are the oldest and only remaining Wonder of the Ancient World. They were built as the final resting place for the rulers of ancient Egypt. The Great Pyramid of Giza is considered to be one of the Seven Wonders of the Modern World, and only one of two monuments from the Ancient World to remain on the list.
Also Read : The Top 10 Expensive Airports For Private Jet Landings
Conclusion
The buildings and monuments that have stood the test of time are truly incredible to think about. They are incredible feats of engineering and architecture, and are a great example of the power of architecture to inspire and awe people. These architectural wonders are still awe-inspiring today, and they remind us of the past as well as inspire us with the future. | https://trustedadnetworks.com/amazing-historical-structures |
Where is chichen itza in mexico
Where Chichen Itza is located?
Mexico
How far is Chichen Itza from Cancun?
about 120 miles
What is Chichen Itza famous for?
Chichén Itzá is a large Mayan city famous for a large, pyramid temple built by the Maya civilization. It is on the Yucatán Peninsula, about 120 km to the east of Mérida. The temple, called Castillo, is about 1 km in diameter. There are many temples and pyramids at Chichen Itza .
What happened at Chichen Itza?
Historical Overview. The name Chichen Itza probably derives from a large sinkhole known as the Sacred Cenote or ‘mouth of the well of the Itza ‘ into which the Maya threw offerings of jade and gold, and as the presence of bones testifies, human sacrifices.
What is inside of Chichen Itza?
Scientists have found a second pyramid hidden deep within the Kukulkan pyramid at the Mayan ruins of Chichen Itza in Mexico. Researchers announced the discovery Wednesday of a pyramid 10 meters tall (33 feet) inside two other structures that make up the pyramid also known as El Castillo, or the Castle.
Can you still climb the pyramid at Chichen Itza?
You are no longer able to climb the ruins at Chichen Itza and have not been able to for several years now. You are still able to climb Coba and Ek Balam, both of which are only partially excavated/restored and well worth visiting. Its been years since you could climb the ruins at either Chichen or Tulum.
Is it worth going to Chichen Itza?
Chichen Itza is one of the new seven wonders of the world, and one of the most popular destinations in the Yucatan Peninsula and Mexico. The Mayan site is definitely worth a visit, and although it can get horrendously busy, follow these tips and you’ll get the most out of your trip!
How much time do you need at Chichen Itza?
The pick-up time depends on where you ‘re located, but in general expect about a 2 to 3 hour ride to Chichen Itza . Once there, you ‘ll have anywhere from 1 to 1.5 hours with a guide (presuming you go on a guided tour) plus approximately one-hour free time .
Is it safe to travel to Chichen Itza?
Despite all rates of unsafe Mexico’s places, Chichen Itza is far from dangerous . The place receives over a million tourists a year and approximately 70% of them are foreigners. You can imagine that this one of the most visited places in the world. So, it’s totally safe to visit .
How much does it cost to go to Chichen Itza?
Chichen Itza Entrace Fee The entrance fee at Chichen Itza is: $481 Pesos per adult, Kids under 13 years are admitted free. The entrance fee to the site is divided into two amounts, one being the state (culture) and the second being the federal (INAH). The fees are paid at two separate windows.
When was the last time you could climb Chichen Itza?
2006
Why is Chichen Itza a 7 wonder?
Chichen Itza is one of the “New 7 Wonders of the World ” due to its large concentration of culturally-significant, ancient manmade wonders and its placing in the top 7 of all nominees during international voting. In 2000, the New7Wonders campaign set out to choose the New 7 Wonders of the World .
Who was the leader of Chichen Itza?
Hunac Ceel
Why are Mayans so short?
Genetic/genomic expressions do not change in such a brief period of time, therefore, all evidence suggest that the short stature of the Maya is due to a combination of environmental and epigenetic factors.
How did the Mayans build Chichen Itza?
All the buildings of Chichen Itza are made from stone. It’s also thought that the Maya did no use the wheel to build any of their temples, pyramids or palaces. Some of the most famous buildings in Chichen Itza that have survived include: The Warrior’s Temple, El Castillo, and The Great Ball Court. | https://lastfiascorun.com/mexico/where-is-chichen-itza-in-mexico.html |
Another step-pyramid structure with a temple at its peak. Morris who published the work from this expedition in two volumes entitled Temple of the Warriors. Unlike the tzompantli of the highlands, however, the skulls were impaled vertically rather than horizontally as at Tenochtitlan.
There is evidence of the sacking of the city sometime after the 12th century and some Maya traditions claim that the city was conquered by the ruler of Mayapan, Hunac Ceel.
El Mercado This square structure anchors the southern end of the Temple of Warriors complex. Today several thousand show up to see the light-and-shadow effect on the Temple of Kukulcan in which the feathered serpent god appears to crawl down the side of the pyramid.
The second phase of monumental buildings in Chichen Itza was from the 11th century to the 13th century. Just like in the rest of Latin America, Guatemalans speak Spanish. The Hacienda Chichen staff is proud to have had the opportunity to represent Mexico's responsible sustainable tourism, excellent hospitality, and friendly nature.
The southern end of the building has one entrance. The warrior Toltecs conquered the region aroundand rebuilt the pyramid as their ceremonial center. Temple of the Warriors: A fascinating Mayan architectural design, shaped similar to a modern Observatory structure.
Shooting of Tikal pyramid went very smoothly. Sacred Cenote The Sacred Cenote. Chichen Itza Archeological Zone: Chichen Itza in Mexico is a good example of this, whereby the suns shadow in the March equinox appears as a serpent slithering down the pyramid.
They were usually two buildings comprising one room each. Hacienda Chichen Resort is the top recommended by most International travel sites and visitors among the hotels in the area, please view our rooms and rates pages and contact us at: Archaeologists today believe neither that the structure was a tomb nor that the personages buried in it were priests.
Via its port at Isla Cerritos on the northern coast, Chichen Itza became an important commercial center, trading in goods—including gold and other treasures—with other cities throughout the Americas.
The city was home to one of the most diverse populations of any Mayan city, which is reflected in the presence of many different architectural styles in the Chichen Itza constructions.
Cenote at Chichen Itza A large cenote sacred well or spring located at the northern end of Chichen Itza has immense ceremonial and archaeological significance. This bird is a vibrantly colored Central American bird which would have captured the eyes of the Mayans. Wyllys Andrews IV also explored the cave in the s.
At the top of the stairway on the pyramid's summit and leading towards the entrance of the pyramid's temple is a Chac Mool. KukulKan Ceremony based on ancient Mayan Cosmovision. It becomes even more amazing when we realize that they did not have metal tools, the wheel, or pack animals.
Mayan architects used a variety of methods to enhance the beauty of their buildings. Almost always they elevated temples and palaces by building them on top of pyramids, platforms, and acropolises. The ruins of the city today include some of the best architecture that was constructed by the Mayans in Chichen Itza in the heyday of the city.
These include the El Castillo step pyramid, a great ball court, a skull platform, a huge temple of the warriors, the Osario pyramid, the Temple of Xtoloc among others. CHICHEN ITZA PRIVATE TOUR. Visit Chichen Itza, a magnificent and stunning pre-Columbian Mayan city located deep in the Yucatan jungle.
you are sure to gain a deep understanding of the magnificent Mayan Empire and the amazing city of Chichen Itza and what it represented to the Mayans.
Don't hesitate to ask questions, our guides love to. Scientists have found a second Mayan pyramid inside El Castillo, or the Castle, at Chichen Itza in Mexico.
Nesting Doll Pyramid: Ancient Mayan Structure Found Inside Chichen Itza.
Chichen Itza in Mexico is a good example of this, whereby the suns shadow in the March equinox appears as a serpent slithering down the pyramid. Much of the architecture is aligned to the sunset of August 13th, the first day.
Chichen Itza was a large pre-Columbian city built by the Maya people of the Terminal Classic period. | https://fulejixomowyz.parisplacestecatherine.com/an-introduction-to-the-architecture-of-the-pyramide-chichen-itza-by-the-mayans-30529nt.html |
Hi,
we are going to be on a cruise with a stop in Belize City, January 28 from 7 am-- 4 pm (Belize time).
We are 3 middle aged people. I'm fit and love ruins (have been to Ek Balam, Coba, Chichen Itza and Tulum all in Mexico).
The other 2 in our group have never seen ruins and aren't as fit as I am.
We are rethinking our original plan of snorkeling in Belize and are considering a ruins trip now.
Does anyone have any private guides that have good reputations?
Which ruin might be a good fit for us and our time frame?
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Since you are interested in Mayan ruins, I'd see if Tikal is offered as an excursion (this will probably be by air and the excursion will be expensive). A friend was on a HAL cruise last year and Tikal was offered as a shore excursion it cost about $300. I can't remember if this was from the port in Belize or another port
If the Tikal excursion is offered by the cruise line, and the price is within your budget, I'd visit Tikal. I've been to Chichen Itza, Tulum, Tikal, Palenque and Copan. Tikal is the most impressive Mayan sight I have seen. The pyramids in Tikal are built in the Peten style and are similar to the pyramids you will have seen at Coba. The Tikal pyramids are the tallest that have been found thus far. If you are interested in Mayan ruins, Tikal is a must see.
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Thanks for the quick reply justshootme.
I would LOVE to visit Tikal someday! Our cruise doesn't off it and I think it's too far to go on our own without worrying about missing the ship :)$300 would be WAY over our budget too.
Hopefully, we'll find a reliable private guide that will get us away from the large groups. Hopefully to our chosen ruin before the ship's tours.
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We used 2 guides last summer who worked out well for us:
Raul Marchand: 628.6438 [email protected]
Leonard Russell: 209.2055 or 625.9830
Phone numbers need 011.501 added to the front if you’re calling from the US.
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Thanks hopefulist,
I will email Raul.
Does Leonard have an email address? It would be very expensive for us to call Belize and talk for any length of time I'm sure.
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No, Leonard (most people call him Russell) doesn't have email access - I asked. There are fairly inexpensive ways to call (we use a distance server called Hello World for our international calls unless we're skyping with relatives) but it feels better sometimes to have the confirmation of an email. Keep me posted!
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Thanks hopefulist.
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Google Mark McField, an expert
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Hi Katie, | https://www.fodors.com/community/mexico-and-central-america/private-guide-for-1-day-stop-in-belize-819771-print/ |
Facts About Mayan Temples in Mexico
The territory of the ancient Mayans spanned what is today Mexico, Guatemala, Honduras, El Salvador and Belize. Mexico is home to the largest concentration of Mayan temples, primarily in the states of Chiapas, Tabasco, Campeche, Yucatan and Quintana Roo. Hundreds of excavated and unexcavated temples exist in these areas, and archaeologists continue to make new discoveries about these ancient structures.
Three Major Sites
Three of Mexico's large and important Mayan temples are in the cities of Uxmal, Chichen Itza and Palenque. These sites are considered major due to their size, the extensive level of restoration and relatively easy accessibility for tourists. Each archeological site contains ball courts, temples and pyramids and is in proximity to major highways. Nearby hotels and other types of accommodations provide the opportunity for overnight visits.
Glyphs and Designs
The Mayan written language used glyphs -- pictographs and symbolic characters. These writings often appear in carvings on temple walls, stone slabs and columns.
The artwork present in the Mayan temples of Mexico varies by location. The temple in Palenque has carvings of warriors, priests and kings, while Uxmal displays intricate stonework that is lattice-like in design. Designs in Chicken Itza include skulls, serpents and depictions of ancient rituals.
Most Famous Temple
Located 75 miles from Merida, Mexico, Chichen Itza is one of the most famous groupings of Mayan temples in Mexico. The temples are more than 1,500 years old and include three groupings of structures: the north, central and southern. Only 30 of the hundreds of buildings that once stood on this location remain. One of Chichen Itza's most popular features is the central pyramid, El Castillo. Built sometime between 1000 and 1200, El Castillo served as a temple to the god Kukulkan. It has four stone stairways, each with 91 steps and, when the top step is counted, there is a total of 365 steps, one for each day of the year. The temple is 98 feet tall and has a 181-foot wide base, which is adorned with huge snake-head sculptures. During the spring and fall equinoxes, the sunset creates triangular shadows that makes it appear as if a serpent is descending the stairs of the temple.
Most Unusual Pyramid
Its round sides and oval base make the Pyramid of the Magician one of the most unusual of the Mayan temples. Located in Uxmal, legend has it that the structure was built overnight by a dwarf-magician god who subsequently became king. Contrary to the legend, however, archeological excavation has revealed that the temple actually was built in five phases. In addition to its shape, the Pyramid of the Magician is known for its acoustics and for the views from its grand terraces. The temple stands 100 feet high and is the tallest structure in Uxmal. | https://getawaytips.azcentral.com/mayan-temples-mexico-1848.html |
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03:51, 21 October 2018
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====The Classical Maya====
[[File:1033888864.jpg|thumb
|left|275
|Figure 2. El Castillo is the great Mayan pyramid in Chichen Itza, one of the great Classical Mayan sites.]]
The Classical Maya period lasted from about 250-900 AD, a period that led to the development of large-scale urban areas and monumental architecture. This was a period of city-states and competing polities rather than a single, long-lived and dominant entity. Scholars have compared it to the period of city-states in ancient Greece or Medieval Italy. Some of the largest centers likely had populations of over 100,000 people, occupying areas around Honduras, Guatemala, and southern Mexico. The great Mayan cities, such as Tikal, were politically involved and often influenced by Teotihuacan, the great central Mexican city to the north that likely was the largest city in pre-Columbian Americas, with perhaps nearly 150,000 people. One of the other great cities at this time was Calakmul, which formed as a rival to Tikal. Chichen Itza (Figure 2) to the north in the modern Yucatán, and Copan, to the south in Honduras, also competed with these cities and likely formed alliances, including with Teotihuacan while sometimes coming under influence of the great powers. The great Maya pyramids were built at this time, which represented temples to the gods and places of sacrifice. Writing was developed, including monumental inscriptions and calendars used to mark events and important cycles. As writing was now used on monumental inscriptions, these provided also dates in which buildings can be attributed to. By around 900 AD, the number of new building inscriptions declines steadily. Soon after this, some of the great cities were either abandoned or were much reduced in population. This has led some scholars to call this sudden change as the "Classic Maya Collapse." Initially ideas centred around warfare or even disease; however, some scholars noted the rapid changes evident in societies and abandonment suggested something different and more drastic. Out of the possibilities that could lead to collapse, it began to emerge that climate might be a major factor in the decline of the Mayas.<ref>For more on the Classical Maya, see: Houston, S. D., & Inomata, T. (2009). <i>The classic Maya</i>. New York: Cambridge University Press. </ref>
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If you are planning a trip to Tulum, Cancun, Merida, or any of the cities of the Yucatan Peninsula, then visiting the Mayan ruins of Chichen Itza is probably high up on your list of things to do in the Yucatan. In this guide, I will give you everything you need to know about visiting Chichen Itza, what to bring, and what to know prior to your visit, as well as the best Chichen Itza tours to visit this amazing archaeological site.
All About Chichen Itza
Chichen Itza is one of those must-visit ruins, what is left of a once classic civilization that thrived in the midst of the jungles of Central America. The ancient Mayans were considered to be the best builders in the New World, having completed some of their most incredible structures when Europe was still in the Dark Ages.
Chichen Itza in Mayan means “at the mouth of the well of the Itza” from chi meaning mouth, ch’en means wells and Itza for the people who last inhabited this city.
This was one of the biggest cities in Mesoamerica and in its height, more than 50,000 people inhabited Chichen Itza. It has been inhabited by the Mayans for more than a thousand years until they abandoned it in the mid-15th century.
The area is about 10 square kilometers (4 square miles) and is fed by two big cenotes which were also believed to be a passageway to the afterlife. These wells were wells of sacrifice and where offerings to the Rain God were done.
Two things were of supreme importance to the Mayans: corn and blood. They believed that the gods made men from corn and mixed it with blood. So corn or maize was the sustenance and the blood was the sacrifice.
The ancient Mayans believed in blood sacrifice to their gods and in countless cenotes in the Yucatan (here’s a guide to the best cenotes in Mexico), you can find hundreds of bones believed to be from human sacrifice.
We can say that for every Egyptian pyramid, the Mayan built 10 pyramids of their own, albeit on a much smaller scale. Dotting the whole Yucatan Peninsula are not only pyramids, but grand temples, observatories, aqueducts, roads that stretch for miles, pools, and many interesting structures.
And Chichen Itza itself is a testimony to the great Mayan civilization who was way ahead of its time in engineering, mathematics, architecture, construction, and astronomy.
Mayans used different stone and wooden tools to make these massive structures in the middle of the jungle. Their use of mathematics was far more advanced than the Greeks and Egyptians at that time.
As early as the 4th century AD, they already had the concept of zero (0). The Golden Ratio was very important to them and they used it in all of their buildings.
All these technological advances were used extensively by the Mayans to build roads, called sacbes, which stretched on for miles from Chichen Itza making it easy for the delivery of goods and services to the city and around the region.
Aqueducts were built in and around the castle because of the abundance of rivers and streams that they had to divert. In the castle and some of their structures, they were able to direct and create water pressure so they already had running water (the European castles had no running water and hygiene was left to be desired).
The Mayans has high regard for the sun and they were very accurate with their calculations for when to plant crops, for when the summer solstice will be and so on.
So accurate that on the sunrise and sunset of the fall and spring equinoxes, the corner of the pyramid casts a shadow meant to represent the feathered serpent god coming down from the north side as the sun goes down.
What amazes me more is the fact that they already had calculations into the future and their calendars are so accurate that the difference between ours and theirs is a mere 33 seconds for each solar calendar year! Crazy accurate!
So the Mayans were already flourishing in the jungles of the Yucatan Peninsula for more than a thousand years. They built the main Temple of Kukulkan, also known as El Castillo, which is a 79-foot step pyramid.
This is the main structure that towers above all else since it was the principal ceremonial center. It has 4 sides with 91 stairs each and one final step at the top… When you add that up, it is equal to 365 days which represent the days of the solar year.
Some of the more popular sites in the area include the Great Ball Court, the Temple of Warriors, and an ancient observatory called El Caracol. The other structures are the following: the Platform of Eagles and Jaguars, the Platform of Venus, the Tzompantili, The Temple of the Jaguars, the Nunnery, Akab Dzib, La Iglesia, and the Temple of the 1,000 Columns.
Chichen Itza was declared a UNESCO World Heritage site in 1988 and was one of the largest Mayan cities in the Yucatan Peninsula. It was also recently declared as one of the Seven New Wonders of the World. This archaeological site is certainly a must-see when you visit Mexico.
Visiting Chichen Itza – Before You Go
Going to Chichen Itza requires a bit of preparation and planning. For one, you’ll have to get there from wherever you’re staying in Mexico…
Most people go by tour, which is recommended and what we’ll be talking about further on, but some also choose to rent a car in Cancun and then make the drive themselves. Driving in the Yucatan is pretty relaxed, but corrupt cops aren’t exactly a rarity and parking at Chichen Itza can be pretty crazy as the tour buses arrive.
Of course, you definitely want to make sure you have enough water since you will be exploring the site which is quite big and the weather here is hot, which means you’ll definitely need some hydration. You also need some sunscreen because you are directly under the hot Mexican sun for many hours.
Do bring your hat and shades too. The entire area around the main pyramid is basically open and exposed to the hot, tropical sun.
And since you are in the jungle, I’d recommend not wearing any cologne or perfume because it can attract a lot of insects. Instead, you’ll have to slather up with insect repellent just to try and keep the mosquitoes at bay.
Do be sure to wear comfortable and sturdy footwear because you will be walking A LOT. Comfortable footwear is a definite must because you probably won’t enjoy your time there if you have blisters the first hour of walking around.
You also might want to bring extra clothes and your swimwear because there are very beautiful cenotes to swim in around Chichen Itza. It is nice to chill in the cool and pristine waters of the cenote after you have been baked by the sun while going around the site.
And last but not least, you need to bring some cash with you so you can buy some souvenirs on site. I’d recommend at least buying those chocolates at the square. Thank me later.
Recommended Chichen Itza Tours
There are so many ways to experience Chichen Itza thanks to the numerous tours that can be arranged from virtually any city in the region, no matter if you’re coming from Playa del Carmen, Cancun, Merida, or Tulum.
You can arrange for a full day tour to the site which will typically include a cenote visit or another town like Valladolid, or better yet another Mayan ruin like Tulum.
As with anywhere, you’ll want to make sure you have the budget and time to devote to a full-day tour, which is probably the best way to visit Chichen Itza since you can take advantage of other destinations, but there are also “express” half-day tours.
Many of us travelers like to DIY these things ourselves, but sometimes it is great to have someone take care of all the logistics and planning so you can just enjoy the tour. But make sure you decide on what tour is best for you because there is a massive list to choose from. These are the top, recommended Chichen Itza tours that you can book depending on your interests, time, and budget.
Chichén Itzá, Ik Kil Cenote & Valladolid Day Tour
Duration: 12 hours
From Cancun, Playa del Carmen, Riviera Maya, and Downtown Tulum
This is the highest-reviewed of all the Chichen Itza tours available. Rightfully so because it is packaged with a visit to Ik Kil Cenote and the old city of Valladolid (definitely worth checking out). Plus this tour comes with a buffet meal at a local restaurant to cap off the experience.
Experience Chichen Itza and everything this cool ancient city has to offer in one of the most interesting ruins in the area… After that, you can take a relaxing dip in Ik Kil Cenote after a day under the hot sun, before wrapping it up with a good stroll around the beautiful colonial city of Valladolid.
Book your Chichén Itzá, Ik Kil Cenote & Valladolid All-Inclusive Tour now.
Chichén Itzá & Cenote Maya Day Tour
Duration: 12 hours
From Cancun
Start your day with an early guided tour of Chichen Itza before the bulk of the crowds hit the site. You’ll learn even more about Chichen Itza from the guides as they share their stories about the ancient Mayans and their beliefs. Marvel at their massive structures and learn how they used advanced engineering to build this great city.
Discover the Cenote Maya Native Park and descend into its crystalline waters to cool off. It is one of the most impressive cenotes of the Yucatan with its crystal-clear waters and geological formations. You can go down through a tunnel or use the wooden staircase, which is an adventure in itself.
You can also swim, dive, and go rappelling if that is your game. Or you can even participate in a sacred ceremony with a Maya shaman in this sacred sinkhole. How’s that for an authentic Mayan experience for you? After which, you can enjoy the traditional meal with organically produced vegetables and handmade tortillas.
Book your Chichén Itzá & Cenote Maya: Full-Day Tour now.
Cancun: Chichén Itzá, Valladolid and Hubiku Cenote Day Tour
Duration: 12 hours
From Cancun, Playa del Carmen and Riviera Maya
Visit the Hubiku Cenote and start your day with a cool morning dip at Hubiku Cenote. Get to know more about picturesque cenote cavern pond of Hubiku and the surrounding jungles from your tour guide. After a relaxing swim, you will be feasting on Yucatecan specialties and organic produce before you proceed to the area’s main attraction… Chichen Itza.
Here you’ll be able to learn how the sacbes or the “white roads” were made and how extensive they are. Explore the site grounds and find yourself in one of the biggest ball courts in Mesoamerica. This is where the ancient ball game of Pok Ta Pok was played. You won’t enjoy court, I guess, if you know what losing this game means: death.
Visit the Cenote Sagrado sacrificial pond, and the other structures around Chichen Itza and get to know their importance to the settlement and its people.
And before heading back, explore the charm of the old colonial city of Valladolid, where you can visit the cathedral and stroll around the main square.
Book your Chichén Itzá, Valladolid and Hubiku Cenote Day-Trip now.
Chichen Itza with VIP Access
Duration: 3 hours
From Cancun
Another interesting and comfortable way of experiencing the great ancient city of Chichen Itza is with privileged access from the Mayaland Hotel and Bungalows which is just adjacent to the Site.
See the important buildings like the Temple of Kukulkan, the Nunnery, La Iglesia, Akab Dzib, and Temple of the Warriors. Oh by the way, did you know that the Temple of Columns has 1,000 columns? That is huge!
You can take your time exploring the sites because you have access to the Mayaland hotel where you can enjoy their amenities. You can take a dip in the pool or relax the tropical gardens.
Optional activities that you may book in the hotel is bike riding or horseback riding. From here you can choose to take the Light and Sound Show (which most visitors never experience, since it is at night) or visit the Mayaland Planetarium.
Book your Chichen Itza Entrance Ticket with Hospitality Suite now.
Chichen Itza, Coba and Tulum Private Day Tour
Duration: 12 hours
From: Riviera Maya
Chichen Itza, Coba, and Tulum are 3 of the best Mayan ruins you can visit in the Yucatan area. If you are a history buff or this is your first time visiting a Mayan ruin, this is a good option to delve into the Maya civilization and see the differences between these three amazing archaeological sites.
Start first with Chichen Itza and explore the Temple of Kukulkan and the Temple of the Warriors. Marvel at how accurate the Mayans calculate their calendars through their observatories and advanced mathematics.
Cool down in one of the swimming holes at the Ik Kil Cenote. Get to enjoy a buffet lunch prepared for you before heading to the next ruin which is Coba.
Coba is one of the most authentic and well-preserved ruins of the Maya civilization. Unlike Chichen Itza, you can climb up the tallest pyramid to see the jungles around it.
Proceed to the old ruins of Tulum and get to experience one of the best locations for ancient Mayan ruins — the Caribbean coast. The Tulum ruins is an ancient port city set in the rocky cliffs overlooking the Caribbean Sea. How is that for a full-packed day?
Book your Chichen Itza, Coba and Tulum Private Tour with Lunch now.
Chichen Itza Light and Sound Show with Cenote Chukum
Duration: 13 hours
From Cancun
This day is quite unique. Here’s how: first, you go to the Cenote Chukum in Cenote Hacienda Chukum and swim in one of the sacred sinkholes of the Mayans. After this, you will be treated to a buffet lunch at the Mayaland Hotel before you explore the ruins.
Enter Chichen Itza through a private entrance of the Mayaland Hotel and admire the monuments Temple of the Warriors and Pyramid of Kukulkan up close and personal. This private 2-hour guided tour will help you explore the archaeological site on a more personal level. Imagine how they lived at that time…
If you are tired, you can rest first at the pool of the hotel or with a drink from their bar. You can go back to the site and check out the other important structures.
Here comes the most significant part, and one that most travelers miss… You’ll get to watch an amazing Light and Sound Show after dark.
The story of Mayans will be told through creative projection on the different temples and monuments! This is a unique and different way to experience the beauty and history of the place, and it is a highly recommended Chichen Itza tour.
Book your Chichen Itza Light and Sound Show with Cenote Chukum now.
Chichen Itzá, Ik Kil and Coba
Duration: 12-13 hours
From: Cancun and Playa Del Carmen
Just like this day trip, there are lots of tours going to Chichen Itza from Cancun (also check out the 12 Best Cancun Tours and Activities for Your Next Trip).
Here you’ll get to visit the ancient Mayan sites of Chichen Itza and Coba (perhaps the two most impressive) and see how the ancient Mayans built these astounding pyramids, temples, and observatories.
Swim in Ik Kil Cenote and explore this sinkhole with its crystalline waters. Plus, you get lunch included.
Book your Chichen Itzá, Ik Kil and Coba Small Group Tour now.
Chichen Itza: Sunrise Tour
Duration: 10 hours
From: Cancun and Playa del Carmen
If you want to take the most astounding photos of Chichen Itza (selfies or not), then you have to come in really early to get the good light.
I mean, the main pyramid stands in the middle of a clearing, so when the harsh midday light hits, it kinda kills the photographic appeal — at least for those who are serious about photography. That’s what makes this Chichen Itza tour one of the coolest things that you can do in Cancun if you love photography.
Your expert tour guide will help you understand the important role of this city in the continuation of the Mayan civilization in the post-classical Mesoamerica. It remained as a nexus of worship and pilgrimage until the Spaniards came.
Book your Chichen Itza: Sunrise Tour now.
Yucatan Overview: Chichen Itza and Uxmal 2-Day Tour
Duration: 2-Day Tour
From Cancun
This is a 2-day tour of the most important archaeological pre-Hispanic cities in the Mayan world: Chichen Itza and Uxmal.
Day 1 is reserved for Chichen Itza. Allowing you to explore its different structures and its role for the former inhabitants. Get to know more about this city and its importance to the later period of the Mayan civilization.
You’ll also be able to make use of the Mayaland Resort hotel amenities and here you will be served a buffet lunch.
Next, you’ll proceed to Uxmal to experience the earlier Mayans and their Puuc architectural style. You will then go check in to Hacienda Uxmal to watch the Light and Sound Show at the Nunnery Quadrangle (tickets separately, but this is a must-see too).
Day 2 starts with a delicious breakfast in the tropical gardens of the hotel. Then you will be exploring the rest of Uxmal with a tour of the Governor’s Place, Pyramid of the Soothsayer, and other structures.
This is a good option for those who have the luxury of time (and budget too, because it will obviously quite a bit more expensive). But still, this is a full-packed 2-day adventure that will fill your hearts (and camera) with lots of memories of this incredible corner of the Yucatan.
Book your Yucatan Overview: Chichen Itza and Uxmal 2-Day Tour now.
Chichen Itza: Express Tour
Duration: 7 hours
From: Cancun Hotel Zone
While dedicating two full-days to tour ancient Mayan ruins sounds cool, there are some of you who might even find it hard to break away for a full-day tour like we’ve been discussing above.
Doing a full day tour will allow you to maximize your time in the area by visiting some other fun and interesting destinations, if you just can’t find the time (or money), then you’ll be best served with a half-day tour of Chichen Itza.
This Chichen Itza express tour will allow you to get to these incredible ruins and back from Cancun with time to visit the main sites as well as offering a bit of free time to wander the grounds on your own.
Since this is an express tour, it does not include hotel pick-up and drop-off, but rather you’ll have to head to the meeting point in the Hotel Zone where you’ll be able to grab the bus. This slight inconvenience means cheaper prices on the tour though, so that’s a plus! Just note, that this tour does not include local taxes.
Book your Chichen Itza: Express Tour now.
More Mayan Ruins in Yucatan Peninsula
I’m sure you have come across several different Mayan ruins in Yucatan while reading this article or from your research of where to go in Mexico.
I’d highly recommend including a few more of these Mayan ruins on your trip while you are in Tulum, Merida, Cozumel, or Cancun. Chichen Itza is incredible, but some of the other ruins offer fewer crowds and just as impressive ruins, sometimes in even more spectacular settings…
- Tulum Ruins is a well-preserved ruins of an ancient Mayan port city in the town of Tulum. It is perched on the rocky cliffs of the Tulum beach overlooking the Caribbean sea.
- Dzibilchaltun is the ruins nearest to the city of Merida, approximately 10 miles (16 km) away. The most famous of the structures here is the Temple of the Seven Dolls named after the seven small effigies found.
- Uxmal is an ancient classical Mayan city which is one of the most important archaeological sites of Maya culture because it best represents the region’s dominant architectural style. Its beautiful buildings are typical Puuc style just like the Maya huts.
- Coba Ruins is nestled between two lakes which are Lake Coba and Lake Macanxoc. Coba is in the center of the largest causeways known to the ancient Mayan world and is home to several important engraved stelae that document the life and events in the Late Classical Period of Mesoamerica.
- Ek Balam means “black jaguar” in Mayan and this city was once the seat of the Mayan Kingdom. The city has its own walled city with more than 40 buildings inside.
- Muyil was one of the earliest and longest inhabited settlements with artifacts found here to be as old as 350 AD. Situated in the Sian Kaan lagoon, the city is known to have traded through a series of canals (which still exist today) and have traded goods like jade, honey, feathers, chocolate, salt, and chewing gum.
All across Latin America, you can find beautiful ruins of ancient civilizations like Tikal in Guatemala and Macchu Pichu in Peru that are astounding in their sheer size and beauty.
But what is our take away by visiting these places and learning from them? Perhaps one thing we can take away is the importance of time, making the best use of it during our time on earth, because all things come to an end, whether it is our terrestrial lives or one of the greatest civilizations on earth…
The Mayans made great temples, observatories, and castles out of stone that withstood the elements of time and change, even though their civilization did not. We may never know what exactly happened to the Mayan people and why they abandoned their cities, but we know for sure they were far more advanced than any civilization during their time.
I also believe that simply by living more deliberately, choosing to fill our time with travel and adventure, by visiting places like Chichen Itza (and many others) is a good use of our time and financial resources… Come to Chichen Itza, come to Mexico, bring back stories to tell of your own by learning about the incredible stories of the past.
Read Next: 7 Amazing Places to Visit in Mexico that are NOT on the Beach
Traveling to Mexico soon? Don’t forget to check out my ultimate guide in traveling to Mexico. Also, book your lodging on Booking.com now to save. But if you plan to stay for a few weeks, I highly recommend looking for any unit on Airbnb. And don’t forget to purchase travel insurance for Mexico that will help protect you against illness, injury, and theft. I use and recommend World Nomads.
Mexico Travel Tips
Important tips and resources for planning an amazing trip to Mexico, based on my extensive experience traveling across the entire country.
Tools
Instructions
- Book a cheap flight to Mexico with Momondo, or better yet, start travel hacking so you can fly for free.
- Plan a rough itinerary and how long you will spend in each destination. Pick up Lonely Planet Mexico to help with this.
- Work every day to teach yourself Spanish, you want to know as much as possible before you arrive.
- Book your cheap accommodation in advance, at least for the first destinations -- For hostels use: Booking, for cheap hotels use: Hotels.com, for apartments use: Airbnb.
- Reserve your on the ground tours and activities through Get Your Guide.
- Purchase travel insurance for Mexico with World Nomads to protect yourself from illness, injury, and theft while in Mexico.
- Check out my comprehensive guide about traveling to Mexico with information on cities, things to do, places to see, and more.
- Learn more money saving tricks with my top budget travel tips if you want to get more bang for your buck.
- Put together your Mexico packing list.
- Enjoy this incredible country!
Notes
I hope this helped you plan your travels in Mexico! I know it can be a struggle to find accurate and on the ground information when traveling to a new place like Mexico, which is why I started writing so extensively about it!
If you have any questions about Mexico, budget travel, or anything else shoot me an email at [email protected].
(I love getting questions! That is how I get ideas for my blog posts and what to write about!)
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