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4 TYPES OF VOR CHECKS
Your airplanes VOR received must be checked every 30 days for IFR Operations and there are multiple ways pilot's can check their VORs. How are they performed? What do you need to annotate?
Here's what you need to know.
VOR Checks:
VOR Receivers are required to be checked every 30 days for IFR Flight Operations. However, it is also important for VFR Pilot’s to check their aircraft’s VOR Receivers.
What to Write (SLED)
Signature (of pilot performing the check)
Location (of the check)
Error (amount of error detected during check)
Date (of the check)
VOT (VOR Test Facility)
A VOT is coded to emit the 360 Radial in all directions around the facility.
This means the airplane’s VOR Receiver should read either: 360 FROM or 180 TO, regardless of the aircraft’s location in relation to the VOR.
How the check is done:
1. Tune and Identify the VOT.
2. Twist the OBS Knob to center the CDI Needle.
3. Check for proper TO/FROM Indication.
4. The radial selected must be within:
5. +/- 4 degrees of 360 or 180.
Ground Check
With a VOR Ground Check:
• The Pilot must park the airplane in the designated ground spot.
• The Pilot must tune and identify the correct VOR.
• The Pilot must use the ground check sign to know:
• Which radial he/she should be on.
• Whether he/she should have a TO or a FROM Indication.
How the check is done:
1. Park aircraft in designated check spot.
2. Tune and Identify the Correct VOR.
3. Twist the OBS Knob to center the CDI Needle.
4. Check for proper TO/FROM Indication.
5. The radial selected must be within:
6. +/- 4 degrees of Designated Radial.
Airborne Check
With an Airborne VOR check:
• The Pilot must position the airplane over the designated location.
• The Pilot must tune and identify the correct VOR.
• The Pilot must use the information in the Chart Supplement to know:
• Which radial he/she should be on.
• Whether he/she should have a TO or a FROM Indication.
How the check is done:
1. Position aircraft over designated check spot.
2. Tune and Identify the Correct VOR.
3. Twist the OBS Knob to center the CDI Needle.
4. Check for proper TO/FROM Indication.
5. The radial selected must be within:
6. +/- 6 degrees of Designated Radial.
Dual VOR Check
With a Dual VOR check, the airplane must be equipped with 2 VOR Receivers.
How the check is done:
1. The pilot tunes both VOR Receivers to the same VOR.
2. The pilot centers both CDI Needles.
3. Check for proper TO/FROM Indications.
4. With both CDI Needles Centered:
5. The Selected Radials should be within 4 degrees of each other.
VOR Check Summary:
• VOT = +/- 4
• Ground Check = +/- 4
• Airborne Check = +/- 6
• Dual Check = within 4 degrees of each other
Author - Nate Hodell
CFI/CFII/MEI/ATP - Creator of wifiCFI - Owner of Axiom Aviation Flight School.
This information is included in the Navigation Aids: VOR Lessons on wifiCFI. Sign up today to watch videos, listen to podcasts, take lesson quizzes, join live webinars, print lesson quicktakes, and more by clicking this link >
where aviation comes to study
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How to Convert A Hexadecimal Number to Decimal in Excel
Sometimes we use hexadecimal numbers to mark products in daily life, and we want to convert these hexadecimal numbers to decimal numbers in some situations. We can convert number between two number types by convert tool online, actually we can also convert numbers by function in excel as well. In excel, =HEX2DEC(number) can help you to convert hexadecimal number to decimal properly, and on the other side, you can use =DEX2HEX(number) to convert decimal to hexadecimal number.
1. Convert Hex Number to Decimal in Excel
As we mentioned above, we can use HEX2DEC function to convert numbers conveniently. Just prepare a table with two columns, one column is used for recording HEX numbers, the second column is used for saving the converted decimal numbers.
Convert A Hexadecimal Number to Decimal 1
Step1: in B1 enter the formula:
=HEX2DEC(A2)
Convert A Hexadecimal Number to Decimal 2
Step2: Click Enter to get returned value. So 21163 in B2 is the mapping decimal number for 52AB.
Convert A Hexadecimal Number to Decimal 3
Step3: Drag the fill handle down to fill the following cells.
Convert A Hexadecimal Number to Decimal 4
Verify that all hexadecimal numbers are converted to decimal numbers correctly. You can also double check the result by convert tool online to make sure the result is correct.
Note:
Sometimes hexadecimal numbers are displayed like 0x52AB, user can remove 0x before 52AB and then use HEX2DEC function to convert number.
2. Convert Decimal to Hex Number in Excel
Prepare another table, the first column is Decimal, the second column is Hex Number.
Convert A Hexadecimal Number to Decimal 5
Step1: in B10 enter the formula:
=HEX2DEC(A2)
Convert A Hexadecimal Number to Decimal 6
Step2: Click Enter to get returned value. So 4D2 in B10 is the mapping hex number for 1234.
Convert A Hexadecimal Number to Decimal 7
Step3: Drag the fill handle down to fill the following cells.
Convert A Hexadecimal Number to Decimal 8
Note:
There are some other functions to convert numbers between different types. See below screenshot.
Convert A Hexadecimal Number to Decimal 9
Convert A Hexadecimal Number to Decimal 10
Convert A Hexadecimal Number to Decimal 11
3. Video: Converting Hex Numbers to Decimal and Decimal to Hex
In this video, we’ll explore two essential skills: converting Hexadecimal numbers to Decimal and Decimal numbers to Hex in Excel.
4. SAMPLE FIlES
Below are sample files in Microsoft Excel that you can download for reference if you wish.
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What is In Vitro Fertilization?
An Overview of IVF
In Vitro fertilization (IVF) has become the most popular choice of treatment for couples with various types of infertility. It is generally accepted as the most successful and fastest method available to achieve pregnancy. While it was initially reserved for patients with blocked, damaged, or absent fallopian tubes (tubal factor infertility), IVF is now also used to overcome infertility caused by endometriosis, male factor (sperm) issues, diminished egg quality, ovulatory problems, or other unexplained reasons.
IVF is an advanced method of assisted reproduction in which the man’s sperm and the woman’s eggs are combined in a laboratory where fertilization occurs, and the resultant embryos are then transferred to the woman’s uterus (embryo transfer) in hopes of achieving a pregnancy. Initially, the patient undergoes ovulation enhancement (superovulation) with a combination of injectable fertility medications that results in the development of multiple eggs in both ovaries. When the eggs have sufficiently matured, the transvaginal ultrasound-guided egg retrieval procedure is then performed in the office, with an anesthesiologist present to provide complete pain relief. The patient is discharged home soon after the procedure.
On the day the eggs are harvested, the partner provides a semen specimen from which the sperm are isolated in the laboratory, and used to fertilize the eggs. If a significant male factor is present, such as low sperm concentrations, or a diminished percentage of normal appearing sperm (morphology) or normally motile sperm (motility), intracytoplasmic sperm injection (ICSI) is an extremely useful modality that is employed to maximize the chances for fertilization.
ICSI
Intracytoplasmic Sperm Injection (ICSI — pronounced “ick-see”) is a technique of gamete (sperm/egg) micro-manipulation, or assisted fertilization, in which individual sperm are captured in a microscopic glass pipette and meticulously injected directly into the individual eggs. The resultant fertilized eggs (early embryos) are then allowed to grow and mature in the sterile laboratory conditions in a manner similar to that of standard IVF. In cases where there is a complete absence of sperm in the ejaculate, such as in gentlemen who have previously undergone a vasectomy, microsurgical epididymal sperm aspiration (MESA) or testicular sperm extraction (TESE) is performed by a specialized urologist here in our office for retrieval of the sperm, and ICSI is then carried out.
Embryo Transfer
An appropriate number of fertilized eggs (pre-embryos) are returned into the patient’s uterus three days later following the egg retrieval via Day 3 embryo transfer, or in select cases, the embryos are cultured for an additional 2-3 days and a blastocyst transfer is performed. We are extremely careful to limit the number of embryos transferred so as to help avoid a high order multiple pregnancy (3 or more fetuses) from occurring.
To learn more, please contact us online or by phone at 732-339-9300, or please continue reading on our Frequently Asked Questions page.
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Genesis, 1-3
Genesis, 1-3
Without blaming serpent, Eve or Adam, what do you think is the crime which gets Adam and Eve thrown out of the garden? To say it another way, what is this knowledge which God wants to keep human beings from having?
Eusa Story (Blackboard)
What is Eusa’s crime?
In what way does his story retell the shut-down of the Garden of Eden?
Galileo (Blackboard and Copernicus film: https://www.youtube.com/watch?v=zHUWP9zu4W8)
On the night of January 7, 1610, Galileo has a new “superlative instrument.” He writes, “When I inspected the celestial constellations through a spyglass, Jupiter presented himself.”
p. 64—What does Galileo see when he looks up at Jupiter?
p. 65—Why does he decide, on January 8, to look at Jupiter again?
p. 65–What does he see, on that second night (January 8) when he looks at Jupiter again?
pp. 65-85—Between January 8 and March 1, 1610, what does Galileo do every night that the weather is clear?
p. 85—What does Galileo know for certain by March 1, 1610?
(film) Briefly describe Galileo’s scientific achievement
(film) Briefly describe Galileo’s trial for heresy
(film) Briefly describe the advance of science since Galileo’s day
GALILEO’S OBSERVATIONS OF THE MOON
1—1610: What was happening in your home country at this time?
2—Is Galileo the 1st to create a telescope?
3—With his own self-made telescope, how close is he able to make the moon appear?
4—How far is the moon, actually, from the Earth? How many “terrestrial diameters?”
5—On the 4th or 5th day after “conjunction,” the moon appears to have horns. Explain. See page 40.
6—On Earth, when the sun rises and its light catches the peak of a mountain, what light reaches the valleys on either side of the mountain?
7—How well-lit are the valleys when the sun rises high in the sky?
8—If the surface of the moon is covered with mountains, why does the moon appear to be almost perfectly round? See page 49.
9—Galileo believes that the moon, like the Earth, has an atmosphere. Is he right? See pages 50—51.
10—Even when the moon is dark, it isn’t perfectly dark. It’s as if some faint light is shining on it. Where does this light come from? See pages 53—56.
11—Based on your general knowledge, in what way or ways can you imagine that Galileo’s observations may get him in trouble with the Catholic Church?
The 6th Extinction ppt slides
#6 Describe the trajectory of human population from 4000 BC to 2100 AD (projected)
#9 How does Darwin explain extinction?
#15 How does E. O. Wilson explain extinction?
#19-20 How long have there been human beings? How long have there been ginkgo trees?
#21 What is the relationship between megafauna extinctions around the world and the spread of human beings?
#28 Karl Marx almost seems to admire the “subjection of Nature’s forces to man” which has happened during the brief “rule” of the bourgeoisie. Explain.
The 6th Extinction (text)
Chapter 1—Why are the golden frogs dying? What change in the world is causing the frogs to die?
Chapter 2—pp. 27-28 What does Jefferson write about “the economy of nature,” and what does he expect Lewis & Clark to find on their expedition to the West?
p. 29 How does Cuvier arrive at the conclusion that the bones of a mastodon belong to an “espece perdue (lost species)?”
p. 44 “The thread of operations is broken,” Cuvier writes. Explain.
Chapter 3 pp. 48-52 Lyell, like Darwin, is a “uniformitarian.” Explain.
p. 69 How does Darwin explain extinction?
Chapter 4 pp 74-78 in 1977, Walter Avarez sends soil samples to a colleague, Frank Asaro. In 1980, Walter Alvarez and his father, Luis Alvarez, publish a paper, “Extraterrestrial Cause for the Cretaceous-Tertiary Extinction.” What is their theory? What is their evidence ?
p. 91 Paul Taylor says about the death of the ammonites that, in certain moments, “the rules of the survival game” abruptly change. How is this a restatement of Cuvier’s idea that “the thread of operations is broken?” How does this theory put a major dent in Darwin’s theory of how extinctions take place?
Chapter 5 pp. 107-108 Paul Crutzen argues that the Earth is now in a new phase of extinction which he calls the Anthropocene. Name 5 geologic-scale processes which people are now causing.
Chapter 6 p. 113 How much CO2 will there be in the air by 2050? What global warming effects can be expected?
pp. 113-114 How much of this CO2 finds its way into the world’s oceans? How much more acidic will the oceans be than they were at the start of the Industrial Revolution?
pp. 116-117 How do the underwater CO2 vents along the sides of the Italian island, Castello Aragonese, offer scientists an “underwater time machine?”
pp. 121-124 How does ocean acidification increase “the cost of calcification?”
Chapter 7 pp. 128-130 How do coral reefs get built? How do they change the world?
pp. 136-137 With ocean acidification, what will happen to the world’s coral reefs? What will happen to their “tenants?”
Chapter 8 pp. 151-153 Imagine walking from the North Pole to the equator. To what degree are there more species in the tropics than anywhere else? Describe 3 theories to explain this difference.
p. 161 According to Darwin, how do species respond to temperature change?
p. 167 Describe 2 different predictions for the % of species loss by 2050, based on temperature change alone.
Chapter 9 p. 176 How much ice-free “wildlands” exist today?
p. 177 what is a “fishbone” pattern of deforestation?
p. 186 As a result of tropical deforestation, how many insect species are being lost every year?
p. 189 Describe the “dark synergy” between fragmentation and global warming.
Chapter 10 p. 197 What is meant by word, “Pangaea?”
pp. 204-205 just as golden frogs and other amphibians are being wiped out by chytrid fungus, little brown bats are being wiped out by white nose syndrome. How are human beings to blame?
pp. 205-208 What is an “introduced species?” How can it be argued that human beings are causing a “New Pangaea?”
Chapter 11 p. 221 Human beings “have brought (the Sumatran rhinoceros) so low that it seems only heroic human efforts can save it.” Explain.
p. 226 “What happened to all these Brobdingnagian animals? Cuvier, who was the first to note their disappearance, believed they had been done in by the most recent catastrophe: ‘a revolution on the surface of the earth’ that took place just before the start of recorded history.” Explain.
p. 234 It appears that the Anthropocene era does not begin with the Industrial Revolution, but with the dispersal of human beings around the earth. Comment.
Chapter 12 pp.246-247 Neanderthals are gone, but something like 4% of our genes today are, in fact, Neanderthal genes. Explain.
p. 249 Human children do not seem to be brighter than ape children except in one regard. What is it?
Chapter 13 p. 260 What is the Frozen Zoo?
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Frequently Asked Questions
We have put together a list of Frequently Asked Questions to help you understand better what’s involved with Chiropractic and our Body in Balance clinic. If you can’t find the answer to your question, please phone us or use the form at the bottom of the page and we will answer your question directly.
Does treatment hurt?
Treatment is usually painless, and most patients look forward to and enjoy the experience (children often laugh!).
Sometimes though, especially after the first one or two treatments there may be a temporary reaction to treatment such as soreness similar to that felt after a work out, or tiredness (usually resulting in a good night’s sleep)
I saw on Trevor MacDonalds Tonight programme on TV that back problems can be cured by taking fillings out it was reported by Jonathan Maitland – is this true?
The TV programme showed the opinion of one practitioner regarding one specific patient. As a Chiropractor, I am trained to take a full history and carry out a through examination of a patient – following on from this I will share my findings and recommend a treatment programme.
Chiropractors may refer a patient for other tests or to other healthcare professionals. Each patient is different and the approach that an individual chiropractor may take in each case can vary, but has the aim of treating the problem through chiropractic treatment and then seeking to prevent re-occurrence in the future through individual exercise programmes, diet and lifestyle advice.
We describe this as a patient focused package of care. Along with my fellow chiropractors in the UK, I am regulated by the government appointed regulator, the General Chiropractic Council and abide by their strict codes of practice.
As a BCA member I have completed a minimum four-year full-time degree level education in chiropractic and am required by the regulator to demonstrate continuous learning and professional development each year.
How long will a visit to the Pain Relief Centre take?
Please click the following link to our “What to Expect” section on the Start Here page. You will find all the relevant details as well as an overview of the treatments and therapies we offer.
What does a chiropractor do?
A chiropractor checks your spine, and often your limbs, jaw and cranial bones, to see if you have any misalignment’s, stiffness or instability. When you have a misalignment, your spinal bones (vertebrae) create havoc with your nervous system and cerebro-spinal fluid flow.
This interference disturbs the neurological impulses flowing from your brain to your body and from your body back to your brain. Your brain then can no longer keep the body healthy.
As a result this can cause a negative effect on the body, a weakened immune system, arthritis and other diseases.
Do I need to contact my GP?
Only if you want to, or if you need a referral letter for private medical cover. We may, with your permission send a report to your GP to keep your medical records up to date.
Are Chiropractors ‘real’ doctors?
In the sense that doctor means ‘educator’ then yes, most chiropractors spend time educating their patients about health and well-being. Something medical doctors ironically rarely have time for.
In the legal sense, yes again, chiropractors can call themselves doctors as long as they make it clear they are not medical doctors.
Chiropractors are trained similar to medical doctors for the first two years, but then spend much more time on neurology, orthopedics, physical assessment, radiology and radiography.
Medical doctors spend this time learning about drugs, surgery and disease.
Is there any parking at the clinics?
At Body In Balance in Brookmans Park, you will find free parking right by the clinic.
How long will it take to get better?
As every body is unique this is very difficult to answer until you have been examined. It also depends on what you mean by ‘better’. Most people mean ‘how long before I’m out of pain?’ Pain can start to reduce right from the very first treatment or may take several sessions.
At Body In Balance our initial objective is to relieve the pain. Once we achieve this we work with you to help to “fix” the underlying problem and help you to get ‘better’ from a medical point of view.
A rough guide can be given though, as most people feel relief within 6-8 treatments over a few weeks, whereas to be healed to prevent reoccurrences would usually take a minimum of 3 months of care for simple cases in healthy, active people.
The longer you have had a problem, and the poorer your general condition and health, the longer it will take. The longer you leave a problem the more attention will be required to rectify it.
Can I have Chiropractic care after surgery?
Yes. Some techniques can be used directly after surgery to help speed up the healing process. If you had surgery for a specific problem and you still have pain – do not give up hope, chiropractic, and the correct exercise, has helped many people recover.
Can people with osteoporosis get chiropractic care?
Of course. When developing a care plan the unique circumstances of each patient are considered. There are many ways to adjust the spine.
The method selected will be best suited to your age, size and condition. Also, we can give you up to date advice on how to combat osteoporosis including what exercise to do, what foods and drinks to avoid that weaken your bones, and what supplements and foods may be of benefit.
How can chiropractic treatment benefit you?
Alleviates pain and discomfort. Helps you return to normal activity. Prevents recurrence. Promotes good health and well-being – please see articles in download section for more details.
What do chiropractors treat?
The primary goal for a chiropractor is to remove interference from your body’s own capacity to heal. So in a medical sense chiropractors treat nothing in particular, but can help in almost all health conditions.
For a list of the main problems seen by chiropractors please go to our Start Here page
What is the difference between Chiropractic and Osteopathy?
Well to be honest there can be more similarities than differences. Both try to improve health by mainly working on your spine.
What differs are the techniques learned at college. Some chiropractic and osteopathic techniques are very gentle, and some can seem very rough.
Very often it is the practitioner themselves that are the difference, rather than the profession. On the whole though osteopathic treatment tends to take longer to perform.
A final difference is that chiropractors learn to take and interpret X-rays.
Find Us and Contact Us
Address
9 Bradmore Green
Brookmans Park
Hertfordshire AL9 7QW
Phone
Use the form below to contact Body In Balance
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Asbestos health problem
Over time, accumulated asbestos fibers can cause tissue inflammation and scarring, which can affect breathing and lead to serious health problems low levels of asbestos fibers are present in the air, water, and soil. Asbestos poses health risks only when fibres are present in the air that people breathe health risks of asbestos also find out how to properly handle a potential asbestos problem asbestos, if inhaled, can cause cancer and other diseases on this page. People who get health problems from inhaling asbestos have usually been exposed to high levels of asbestos for a long time the symptoms of these diseases do not usually appear until about 20 to 30 years after the first exposure to asbestos. In general, the greater the exposure to asbestos, the greater the chance of developing harmful health effects disease symptoms may take many years to develop following exposure asbestos-related conditions can be difficult to identify. Asbestos an environmental and a health problem by dr hussein fatehy mahmoud phd-fccp -mcts consultant pulmonologist abbassia chest hospital cairo-egypt 2 agenda asbestos overview asbestos- an environmental problem asbestos-a health problem role of egyptian press media in asbestos banning role of egyptian government in asbestos banning take.
asbestos health problem Asbestos deaths remain a public health problem : shots - health news exposure to the tiny fibers in asbestos can lead people who work around the material to develop mesothelioma, a cancer of the.
Asbestosis is a serious long-term lung condition caused by prolonged exposure to asbestos asbestos is a whitish material that was used in buildings for insulation, flooring and roofing in the past, but is now no longer used. The port allegany asbestos health program (paahp) is a unique, community-run program that resulted from the successful cooperative efforts of a labor union, a corporation, community health care providers, and a medical school. Asbestos still kills around 5000 workers each year, this is more than the number of people killed on the road around 20 tradesman die each week as a result of past exposure however, asbestos is not just a problem of the past it can be present today in any building built or refurbished before the.
The world trade center health registry estimates about 410,000 people were exposed to a host of toxins including asbestos during the rescue, recovery and clean-up efforts that followed 9/11 people most affected by asbestos at ground zero were people assigned to rescue survivors. Workers exposed to asbestos have an increased risk of developing lung cancer this risk is greatly increased if the person smokes it is very difficult to distinguish lung cancer caused by asbestos and that caused by smoking or other environmental pollutants, so it is often very difficult to get a clear diagnosis of asbestos-related lung cancer. Asbestos in some form is in millions of homes, but i haven't been able to find statistics on the health effects of asbestos exposure in the home that doesn't mean they aren't there, but the cases of health problems from occupational exposure dominate. In may 2018, the epa published a document known as the “problem formulation of the risk evaluation for asbestos,” which establishes the scientific approach the epa will take in evaluating. Hd historic stock footage - story of asbestos mining and mfg 1920s - duration: 11:38 buyout footage historic film archive 11,743 views.
The legal limit for safe exposure to asbestos in the workplace is now 01 fiber/ml, so any asbestos measurement in the home of 01 fiber/ml or greater is a health concern. Once they are trapped in the body, the fibers can cause health problems asbestos is most hazardous when it is friable the term friable means that the asbestos is easily crumbled by hand, releasing fibers into the air. Asbestosis is a lung disease that develops when asbestos fibers cause scarring in your lungs the scarring restricts your breathing and interferes with the ability of oxygen to enter your bloodstream.
asbestos health problem Asbestos deaths remain a public health problem : shots - health news exposure to the tiny fibers in asbestos can lead people who work around the material to develop mesothelioma, a cancer of the.
Asbestos can cause health problems when inhaled into the lungs breathing in very small, airborne asbestos fibres has been associated with diseases such as asbestosis, mesothelioma and lung cancer. The environmental impact of asbestos used in the past as a common part of construction materials, asbestos continues to pose major risks to human health and the environment once it was discovered that it caused health problems, products that contained asbestos were discontinued, but the risks remain. Health problems associated with exposure to asbestos breathing asbestos mainly causes problems in the lungs and the membrane that surrounds the lungs, including: asbestosis : scarring of lung tissue that causes breathing problems, usually in workers exposed to asbestos in workplaces before the federal government began regulating asbestos use. Health problems attributed to asbestos include: asbestosis - a lung disease first found in textile workers, asbestosis is a scarring of the lung tissue resulting from the production of growth factors that stimulate fibroblasts (the scar-producing lung cells) to proliferate and synthesize the scar tissue in response to injury by the inhaled.
• “asbestos” is a commercial name, not a mineralogical definition, given to a variety of six naturally occurring fibrous minerals these minerals possess high tensile strength, flexibility, resistance to chemical and thermal degradation, and electrical resistance.
• Tigerite – geologically compressed blue asbestos white asbestos is also known as ‘serpentine’, as its’ fibres are bendy all the rest are called ‘amphibole’, as their crystals are constructed in columns (and so more rigid and liable to snap into tiny fragments.
• Install asbestos cement pipe, primarily because of issues with handling, there appears to be no concern for health of consumers receiving the water and no programmes to specifically replace asbestos cement pipe for this reason.
Asbestos becomes a health risk when its fibres are released into the air and breathed in breathing in asbestos fibres can cause asbestosis, lung cancer and mesothelioma asbestos was once used in australia in more than 3,000 different products including fibro, flue pipes, drains, roofs, gutters, brakes, clutches and gaskets. Asbestos use continued to grow through most of the 20th century until public knowledge of the health hazards of asbestos dust led to its outlawing by courts and legislatures in mainstream construction and fireproofing in most countries. What is asbestos asbestos is the name given to a group of naturally occurring minerals that are resistant to heat and corrosion asbestos has been used in products, such as insulation for pipes (steam lines for example), floor tiles, building materials, and in vehicle brakes and clutches. Knowledge or suspicion of health issues existed for a long time: the health issues related to asbestos were known, suspected, or reported, for decades, with modern medical coverage dating back to the 19th century.
asbestos health problem Asbestos deaths remain a public health problem : shots - health news exposure to the tiny fibers in asbestos can lead people who work around the material to develop mesothelioma, a cancer of the. asbestos health problem Asbestos deaths remain a public health problem : shots - health news exposure to the tiny fibers in asbestos can lead people who work around the material to develop mesothelioma, a cancer of the. asbestos health problem Asbestos deaths remain a public health problem : shots - health news exposure to the tiny fibers in asbestos can lead people who work around the material to develop mesothelioma, a cancer of the.
Asbestos health problem
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Home | | Chemistry | General properties of Lanthanides
Chapter: 11th 12th std standard Class Organic Inorganic Physical Chemistry Higher secondary school College Notes
General properties of Lanthanides
General properties of Lanthanides
The Lanthanide series include fifteen elements i.e. lanthanum (57 La) to lutetium (71 Lu). Lanthanum and Lutetium have no partly filled 4f- subshell but have electrons in 5d-subshell.
The position of f block elements in the periodic table, is explained above.
The elements in which the extra electron enters ( n- 2 )f orbitals are called f- block elements. These elements are also called as inner transition elements because they form a transition series within the transition elements. The f-block elements are also known as rare earth elements. These are divided into two series.
i) The Lanthanide series (4f-block elements)
ii) The Actinide series (5f- block elements )
The Lanthanide Series
The Lanthanide series include fifteen elements i.e. lanthanum (57 La) to lutetium (71 Lu). Lanthanum and Lutetium have no partly filled 4f- subshell but have electrons in 5d-subshell. Thus these elements should not be included in this series. However, all these elements closely resemble lanthanum and hence are considered together.
General properties of Lanthanides
1. Electronic configuration
The electronic configuration of Lanthanides are listed in the table . The fourteen electrons are filled in Ce to Lu with configuration [54 Xe ]4f1-14 5d1 6s2
2. Oxidation states
The common oxidation state exhibited by all the lanthanides is +3 (Ln3+) in aqueous solutions and in their solid compounds. Some elements exhibit +2 and +4 states as uncommon oxidation states.
La - +3
Ce - +3, +4, +2
Pr - +3, +4
Nd - +3, +4, +2
3. Radii of tripositive lanthanide ions
The size of M3+ ions decreases as we move through the lanthanides from lanthanum to lutetium. This steady decrease in ionic radii of M3+ cations in the lanthanide series is called Lanthanide contraction.
Cause of lanthanide contraction
The lanthanide contraction is due to the imperfect shielding of one 4f electron by another in the same sub shell. As we move along the lanthanide series, the nuclear charge and the number of 4f electrons increase by one unit at each step. However, due to imperfect shielding, the effective nuclear charge increases causing a contraction in electron cloud of 4f-subshell.
Consequences of lanthanide contraction
Basicity of ions
i) Due to lanthanide contraction, the size of Ln3+ ions decreases regularly with increase in atomic number. According to Fajan's rule, decrease in size of Ln3+ ions increase the covalent character and decreases the basic character between Ln3+ and OH- ion in Ln(OH)3. Since the order of size of Ln3+ ions
are
La3+> Ce3+ ............... >Lu3+
ii) There is regular decrease in their ionic radii.
iii) Regular decrease in their tendency to act as reducing agent, with increase in atomic number.
iv) Due to lanthanide contraction, second and third rows of d-block transistion elements are quite close in properties.
v) Due to lanthanide contraction, these elements occur together in natural minerals and are difficult to separate.
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Patents
1. Advanced Patent Search
Publication numberUS4053739 A
Publication typeGrant
Application numberUS 05/713,470
Publication dateOct 11, 1977
Filing dateAug 11, 1976
Priority dateAug 11, 1976
Also published asCA1097407A1, DE2735204A1, DE2735204C2
Publication number05713470, 713470, US 4053739 A, US 4053739A, US-A-4053739, US4053739 A, US4053739A
InventorsRobert Lynn Miller, Robert Neal Weisshappel
Original AssigneeMotorola, Inc.
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Dual modulus programmable counter
US 4053739 A
Abstract
The inventive counter is operable to divide an input signal by the sum of two binary numbers, A and B. Each number is stored in memory. These numbers are alternately preset into a binary counter which also receives the input signal. A logic gate monitors the counter output and changes state when the number previously preset in the counter equals the accumulated count. The gate state transition is used to preset the counter with the alternate stored number. Thus, the process continues whereby the output from the logic gate represents the input signal divided by the sum of A and B.
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Claims(5)
We claim:
1. A multiple modulus counter for dividing a signal having a frequency f by a divisor N = M1 + M2 + . . . + Mx, where N, M1, M2, . . . , Mx are selected numbers, comprising:
counter means including an input for receiving the signal to be divided, an output for producing a signal representative of the count of signals received at the input, and means to input a preset count state;
a plurality of Mx preset means, each actuable to preset one of the numbers M1 . . . Mx into the counter means;
control means responsive to the count state at the counter output to sequentially actuate a successive one of the preset means in response to the counter counting to the count preset into the counter by the preceding preset means, the control means producing an output waveform having transitions corresponding to the actuation of predetermined preset means,
whereby the control means output waveform is of a frequency f/N.
2. A dual modulus counter for dividing a signal having a frequency f by a divisor N = A + B, where N, A and B are selected numbers, comprising:
counter means including an input for receiving the signal to be divided, an output for producing a signal representative of the count of signals received at the input, and means to input a preset count state;
first preset means actuable to preset the count A in the counter means;
second preset means actuable to preset the count B in the counter means; and
control means responsive to the count state at the counter output to sequentially actuate the second and first preset means in response to the counter counting the numbers A and B, respectively, the control means producing an output waveform having transitions at the times of actuating the first and second preset means,
whereby the control means output waveform is of a frequency f/N.
3. A frequency synthesizer comprising:
a reference signal source for generating a reference signal of frequency f;
a phase comparator for producing at its output an error signal representative of the phase difference of signals received at its input;
means for coupling the reference signal source to the first phase comparator input;
a signal controlled oscillator for producing an oscillator signal of predetermined frequency at its output responsive to a received control signal;
means for processing the phase comparator error signal and producing a control signal in response thereto;
means for coupling the produced control signal to the signal controlled oscillator;
prescaler means actuable to frequency divide the oscillator signal by one of two predetermined divisors P, P';
a dual modulus divider for frequency dividing the output from the prescaler by alternate stored divisors A and B, where A and B are selected numbers, the dual modulus divisor including means to actuate the prescaler means from its P divisor to its P' divisor upon transition from the A divisor to the B divisor and from its P' divisor to its P divisor upon transition from the B divisor to the A divisor; and
means for coupling the output from the dual modulus divider to the comparator second input,
whereby the oscillator signal tends to assume the frequency f/(AP + BP').
4. The frequency synthesizer of claim 3 wherein P' = P + 1.
5. The frequency divisor of claim 3 wherein the dual modulus divider comprises:
counter means including an input for receiving the prescaler output signal, an output for producing a signal representative of the count of signals received at the input, and means to input a preset count state;
first preset means actuable to preset the count A in the counter means;
second preset means actuable to preset the count B in the counter means; and
control means responsive to the count state at the counter output to sequentially actuate the second and first preset means in response to the counter counting the numbers A and B, respectively, the control means producing an output waveform having transitions at the times of actuating the first and second preset means.
Description
BACKGROUND OF THE INVENTION
The present invention pertains to the electronic signal processing art and, in particular, to a programmable frequency counter.
Programmable frequency counters have been well known in the electronic processing art, particularly in the frequency synthesizer field. Frequency synthesizers commonly employ standard phase lock loop circuitry wherein a reference frequency oscillator signal may be divided by a selected one of a plurality of divisors thus providing an output signal of desired frequency. Previous techniques employed in digital frequency synthesizers have used, in the feedback portion of a conventional phase lock loop, a variable prescaler, and first and second counters. The first counter has been programmable and is used to divide the output of the variable prescaler by a fixed number (N). The second counter, often referred to as a swallow counter, has been used to switch the variable prescaler to a new divisor, or modulus, which new modulus is present during the counting of "N". As is discussed at page 10-3 of the Motorola "McMOS HANDBOOK", printed 1974 by Motorola, Inc., the total divisor NT of the feedback loop is given by:
NT = (P + 1)A + P(N - A)
where, the variable modulus prescaler operates between two divisors P and P+1, the swallow counter has a fixed divisor A, and the programmable divider has the divisor N.
While the above described frequency synthesizer provided the desired function, it requires a large number of parts and thus is expensive to manufacture. It is desirable, therefore, to provide the frequency synthesizer function using fewer parts.
SUMMARY OF THE INVENTION
It is an object of this invention, therefore, to provide an improved dual modulus programmable counter which is particularly suited for application in frequency synthesizers.
It is a particular object of the invention to provide the above dual modulus programmable counter which employs a minimum of components and, therefore, results in a minimum cost.
Briefly, according to the invention, a multiple modulus divider divides a signal having a frequency f by a divisor N = N1 + M2 + . . . + Mx, where N, M1, M2, . . . , Mx are selected numbers. The improved counter comprises a counter means which includes an input for receiving the signal to be divided, an output for producing a signal representative of the count of signals received at the input, and means to input a preset count state. Also included are a plurality of Mx preset means, each of which is actuable to preset one of the numbers M1 . . . Mx into the counter means. A control means responds to the count state at the counter output to sequentially actuate successive ones of the preset means in response to the counter counting to the count preset into the counter by the preceeding preset means. The control means produces an output waveform having transitions corresponding to the actuation of the predetermined preset means whereby the control means output waveform is of a frequency f/N.
The improved dual modulus programmable counter may be used in combination with further components to comprise a frequency synthesizer. In particular, additional frequency synthesizer components comprise a reference signal source for generating a reference signal frequency f. This signal is coupled, via appropriate means, to the first input of a phase comparator which compares this signal to the signal received at its second input, and produces an error signal representative of the phase difference therebetween at its output. The phase comparator error signal is processed for application to the control signal of a signal controlled oscillator which, in turn, responds by producing an oscillator signal of predetermined frequency. The output from the signal controlled oscillator couples to a prescaler which is actuable to frequency divide the oscillator signal by one of two predetermined divisors P, P'. The aforementioned dual modulus divider frequency divides the output from the prescaler by alternate stored divisors A and B, where A and B are selected numbers. The divisor includes means to actuate the prescaler means from its P divisor to its P' divisor upon transition from the A divisor to the B divisor, and from its P' divisor to its P divisor upon transition from the B divisor to the A divisor. The output from the divider is coupled to the comparator second input whereby the oscillator signal tends to assume the frequency f/(AP' + BP).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram illustrating the inventive dual modulus counter; and
FIG. 2 is a schematic diagram illustrating a frequency synthesizer which employs the inventive counter.
DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION
Referring to FIG. 1, a signal of frequency f, which is to be divided by a divisor N, is applied at the input 12 of a standard binary counter 10. The binary counter 10, operating in the well known manner, produces a signal at its output terminal 14 in response to a predetermined count of the input signal f. The binary counter 10 also has preset count input terminals 16, 18. A binary number coupled to one of the preset count inputs 16, 18 will activate the counter 10 to the binary number. In the present preferred embodiment of the invention, binary counter 10 is of the count-down type which means that a count state preset at the input terminals 16 or 18 will be decremated one count for each received input pulse at input 12. The binary counter 10 responds to counting down to a zero count state by changing its output logic state at output terminal 14.
A change in the output state at output 14 of binary counter 10 activates the "C" input 22 of a conventional control flip-flop 24. Flip-flop 24 has a first "Q" output 26 and a second "Q" output 28. The control flip-flop 24 responds to transition state changes at its input 22 to alternately activate the Q output 26 high and low, with the Q output 28 correspondingly low and high.
The Q output 28 of the flip-flop 24 couples to the input terminals 32, 42 of a pair of preset storage registers 30, 40, respectively. Each register 30, 40 is programmed to contain a preset number. In this case preset register 30 contains the number A and preset register 40 contains the number B. Upon suitable activation at their inputs 32, 42 each register 30, 40 applies the number stored therein to the preset input terminals 16, 18 of the binary counter 10, activating the count in the same to the appropriate number A, B. Each number A, B corresponds to a modulus with which the input signal f will be divided. In this preferred embodiment of the invention a dual modulus system is provided. Thus, there are two preset registers 30, 40 each containing the number A, B respectively. In a generalized system, any one of a number of divisors of modulus M1 + M2 + . . . + Mx might be used, in which case there would be a preset register for each, each containing the appropriate number M1, M2, . . . Mx. For purposes of clarity the following discussion deals primarily with a dual modulus counter. Nonetheless, it should be understood that anyone of ordinary skill in the art could practice the invention by constructing a counter having more than two moduli.
Operation of the dual modulus programmable counter of FIG. 1 may be understood as follows.
Assume initially that the Q output 28 of the flip-flop 24 has activated preset register 30 to place the count A into the binary counter 10. Thus, each successive count of the input signal f reduces the counter by one whereby, finally, the counter reaches a count of zero. At this time the counter output 14 makes a transition thereby activating the control input 22 of the flip-flop 24. At this point the Q output 26 and Q output 28 of flip-flop 24 make a transition to the opposite logic state. This transition causes the second preset register 40 to input the count B into the binary counter 10. Now successive input counts at input 12 of binary counter 10 due to the input signal f reduce the count state of the counter 10 until it again reaches zero, at which point an output transition at output 14 once again activates the control input 22 of the flip-flop 24, thus activating preset register 30 to again input the count A into the binary counter 10.
Henceforth, the cycle repeats and the Q output 26 of the flip-flop 24 assumes a waveform having a frequency f/N, where N = A + B. Thus, with a minimum of components at input signal f is divided by two moduli A, B, thereby dividing the input signal f by the sum of the two moduli, N. As is discussed with reference to FIG. 2, the fact that the control flip-flop 24 produces an output transition after the A count period renders the instant dual modulus programmable counter extremely useful in frequency synthesizer applications.
FIG. 2 illustrates the preferred embodiment of a frequency synthesizer which employs the novel dual modulus programmable counter. There a standard phase lock loop chain includes a reference oscillator 100 which produces a reference signal of frequency f. The signal f is fed to the first input 112 of a phase detector 110. Phase detector 110 has a second input 114 and an output 116. Acting in the conventional manner, the phase detector 110 produces an error signal at its output 116, which error signal is representative of the phase difference between signals received at the input terminals 112, 114.
In the conventional manner, the output error signal at output terminal 116 is low pass filtered through a low pass filter circuit 118 and applied to the control input 122 of a voltage controlled oscillator 120. The voltage controlled oscillator 120 produces an oscillator signal of predetermined frequency at its output 124 responsive to a control signal received at its control input 122. This oscillator output signal is the output signal fout of the frequency synthesizer.
The output terminal 124 of the voltage controlled oscillator 120 also feeds to the input terminal 132 of a variable modulus prescaler 130. The variable modulus prescaler 130 responds to a signal at its divisor input 134 to divide signals received at its input terminal 132 by either one of two moduli P, or P' reproducing the output frequency divided signal at its output terminal 136. In the preferred embodiment of the invention, P' = P + 1, however it should be understood that the selection of the P' modulus is one of individual designer's choice. The frequency divided output 136 of the variable modulus prescaler 130 is applied to the input terminal 142 of the dual modulus programmable counter 150. The dual modulus programmable counter 150 is seen to be identical to the preferred embodiment thereof illustrated in FIG. 1. For example, input terminal 142 is the input of a binary counter 140 corresponding to the binary counter 10 of FIG. 1. Binary counter 140 has an output 144 which feeds to the control input 152 of a control flip-flop 154. The control flip-flop 154 has a Q output 156 and a Q output 158. The Q output 158 actuates the inputs 162, 172 of the preset storage registers 160, 170 respectively. As before, each preset register 160, 170 contains preset numbers A, B, respectively, which, upon actuation via the input terminals 162, 172 feed their corresponding number into the binary counter 140 via the preset input terminals 146, 148.
The Q output 156 of the flip-flop 154 feeds to the modulus control terminal 134 of the variable modulus prescaler 130. A transition in logic state at input 134 causes the variable modulus prescaler 130 to alternate between the P and P+1 divisors. Finally, the Q output 158 of the control flip-flop 154 feeds to the second input 114 of the phase comparator 110.
Operation of the frequency synthesizer of FIG. 2 is understood as follows.
The reference oscillator 100 feeds a signal of frequency f to the first input 112 of the phase detector 110. Phase detector 110, in turn, produces an error signal at its output 116 which, when low pass filtered via the filter 118, controls the voltage controlled oscillator 120. The oscillator output signal from the voltage controlled oscillator 120 is frequency divided by the variable modulus prescaler 130. Assuming that the variable modulus prescaler 130 is activated to its P modulus, the variable modulus prescaler 130 will produce an output transition at its output terminal 136 when it has counted P counts in the oscillator signal. At this time the first count is received by the binary counter 140 at its input 142. Stored within the binary counter 140 initially is the binary number A. Thus, this binary preset count is decremented by one count. This process continues until the variable modulus prescaler 130 counts to the number P, A times. After the binary counter 140 has counted down from its preset input A, it produces an output at output terminal 144 which in turn is applied to the control input 152 of the control flip-flop 144. This transition at the control input 152 causes the Q output 156 and Q output 158 to flip to their opposite states. Thus, the Q output 156 activates the variable modulus prescaler 130 to begin dividing by its second modulus P+1. Also, the Q output 158 causes the number B stored in register 170 to be fed into the binary counter 40. Now, the binary counter 140 does not change its output state at its output terminal 144 until the variable modulus prescaler has counted P+1 counts a total of B times.
Thereafter, the cycle repeats whereby the waveform at the Q output 158 of the flip-flop 154 is of a frequency fout /Nt, where Nt = A(P) + B(P+1). Now, in the conventional manner, the waveform fout /Nt is phase compared with the reference oscillator 100 signal f, whereby the two tend to phase lock producing the output signal fout = f/NT.
Thus, the dual modulus programmable counter 150 replaces the variable counter and the swallow counter of the prior art when used in a frequency synthesizer which provides an output signal which is the frequency division of a reference signal. Since the inventive dual modulus programmable counter does not require both a programmable counter, and a swallow counter, as has been known in the prior art, a significant reduction in parts count, and thus cost, has been achieved.
While a preferred embodiment of the invention has been described in detail, it should be understood that many modifications and variations thereto are possible, all of which fall within the true spirit and scope of the invention.
Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3353104 *Jun 14, 1965Nov 14, 1967Ltv Electrosystems IncFrequency synthesizer using fractional division by digital techniques within a phase-locked loop
US3594551 *Nov 29, 1966Jul 20, 1971Electronic CommunicationsHigh speed digital counter
US3605025 *Jun 30, 1969Sep 14, 1971Sperry Rand CorpFractional output frequency-dividing apparatus
US3714589 *Dec 1, 1971Jan 30, 1973Lewis RDigitally controlled phase shifter
US3959737 *Nov 18, 1974May 25, 1976Engelmann Microwave Co.Frequency synthesizer having fractional frequency divider in phase-locked loop
US3982199 *Jan 6, 1975Sep 21, 1976The Bendix CorporationDigital frequency synthesizer
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4184068 *Nov 14, 1977Jan 15, 1980Harris CorporationFull binary programmed frequency divider
US4231104 *Apr 26, 1978Oct 28, 1980Teradyne, Inc.Generating timing signals
US4241408 *Apr 4, 1979Dec 23, 1980Norlin Industries, Inc.High resolution fractional divider
US4316151 *Feb 13, 1980Feb 16, 1982Motorola, Inc.Phase locked loop frequency synthesizer using multiple dual modulus prescalers
US4325031 *Feb 13, 1980Apr 13, 1982Motorola, Inc.Divider with dual modulus prescaler for phase locked loop frequency synthesizer
US4327623 *Mar 31, 1980May 4, 1982Nippon Gakki Seizo Kabushiki KaishaReference frequency signal generator for tuning apparatus
US4330751 *Dec 3, 1979May 18, 1982Norlin Industries, Inc.Programmable frequency and duty cycle tone signal generator
US4357527 *Jan 25, 1979Nov 2, 1982Tokyo Shibaura Denki Kabushiki KaishaProgrammable divider
US4390960 *Nov 21, 1980Jun 28, 1983Hitachi, Ltd.Frequency divider
US4468797 *Feb 3, 1982Aug 28, 1984Oki Electric Industry Co., Ltd.Swallow counters
US4559613 *Jun 29, 1982Dec 17, 1985The United States Of America As Represented By The Secretary Of The Air ForceDigital frequency synthesizer circuit
US4574385 *Feb 16, 1984Mar 4, 1986Rockwell International CorporationClock divider circuit incorporating a J-K flip-flop as the count logic decoding means in the feedback loop
US4651334 *Dec 24, 1984Mar 17, 1987Hitachi, Ltd.Variable-ratio frequency divider
US4658406 *Aug 12, 1985Apr 14, 1987Andreas PappasDigital frequency divider or synthesizer and applications thereof
US4891825 *Feb 9, 1988Jan 2, 1990Motorola, Inc.Fully synchronized programmable counter with a near 50% duty cycle output signal
US5065415 *Feb 21, 1990Nov 12, 1991Nihon Musen Kabushiki KaishaProgrammable frequency divider
US5066927 *Sep 6, 1990Nov 19, 1991Ericsson Ge Mobile Communication Holding, Inc.Dual modulus counter for use in a phase locked loop
US5195111 *Aug 13, 1991Mar 16, 1993Nihon Musen Kabushiki KaishaProgrammable frequency dividing apparatus
US5202906 *Dec 23, 1987Apr 13, 1993Nippon Telegraph And Telephone CompanyFrequency divider which has a variable length first cycle by changing a division ratio after the first cycle and a frequency synthesizer using same
US5235531 *Dec 13, 1991Aug 10, 1993Siemens AktiengesellschaftMethod and arrangement for dividing the frequency of an alternating voltage with a non-whole-numbered division factor
US5495505 *Dec 20, 1990Feb 27, 1996Motorola, Inc.Increased frequency resolution in a synthesizer
US5781459 *Apr 16, 1996Jul 14, 1998Bienz; Richard AlanMethod and system for rational frequency synthesis using a numerically controlled oscillator
US5842006 *Sep 6, 1995Nov 24, 1998National Instruments CorporationCounter circuit with multiple registers for seamless signal switching
US6035182 *Jan 20, 1998Mar 7, 2000Motorola, Inc.Single counter dual modulus frequency division apparatus
US6072404 *Apr 29, 1997Jun 6, 2000Eaton CorporationUniversal garage door opener
US6725245May 3, 2002Apr 20, 2004P.C. Peripherals, IncHigh speed programmable counter architecture
USRE32605 *Jun 28, 1985Feb 16, 1988Hitachi, Ltd.Frequency divider
WO1981002371A1 *Jan 5, 1981Aug 20, 1981Motorola IncAn improved frequency synthesizer using multiple dual modulus prescalers
WO1981002372A1 *Jan 5, 1981Aug 20, 1981Motorola IncImproved divider with dual modulus prescaler
WO1982003477A1 *Mar 30, 1982Oct 14, 1982Inc MotorolaFrequency synthesized transceiver
Classifications
U.S. Classification708/103, 377/52, 331/25, 331/1.00A, 331/16, 377/47
International ClassificationG06F7/68, H03K23/66, H03L7/193, H03L7/18
Cooperative ClassificationH03K23/665, H03L7/193, H03L7/18, H03K23/667, G06F7/68
European ClassificationH03K23/66P, H03K23/66S, G06F7/68, H03L7/18, H03L7/193
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IBM Certification Questions
Q:
Which of the following extenders allows data to be presented in a three dimensional format?
A) DB2 AVI Extender B) DB2 XML Extender
C) DB2 Text Extender D) DB2 Spatial Extender
Answer & Explanation Answer: D) DB2 Spatial Extender
Explanation:
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Filed Under: IBM Certification
3 1193
Q:
Which of the following DB2 data types CANNOT be used to contain the date an employee was hired?
A) CLOB B) TIME
C) VARCHAR D) TIMESTAMP
Answer & Explanation Answer: B) TIME
Explanation:
Report Error
View Answer Workspace Report Error Discuss
Filed Under: IBM Certification
4 1163
Q:
With database logging, where are transaction records first placed?
A) in the logical log buffer B) in the primary chunk
C) in the physical buffer D) in a temporary database table
Answer & Explanation Answer: A) in the logical log buffer
Explanation:
Report Error
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Filed Under: IBM Certification
4 1088
Q:
The DBA can set the registry variable DB2_HASH_JOIN on or off because:
A) hash joins may require more resources to run. B) hash joins are not used unless outer joins are requested.
C) If hash joins are enabled, no other join method can be used. D) Hash joins are only needed when the tables are portioned using hash keys.
Answer & Explanation Answer: A) hash joins may require more resources to run.
Explanation:
Report Error
View Answer Workspace Report Error Discuss
Filed Under: IBM Certification
4 1073
Q:
Suppose a System z customer has a new CIO. The CIO is concerned about continuing operations and recovery following a catastrophe.Which of the following addresses this issue?
A) GDPS B) TAM
C) DR D) WASS
Answer & Explanation Answer: A) GDPS
Explanation:
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Filed Under: IBM Certification
2 1035
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| 0.999626 |
What determines the CICSGLBL parms MONITOR value after CICS region is recycled?
Document ID : KB000045768
Last Modified Date : 14/02/2018
Show Technical Document Details
Summary:
This knowledge document details a usage scenario of the UTRPARM(CICSGLBL) MONITOR parameter and how to initialize it, and modify it after the CICS region is recycled.
Here is a scenario that was described by a user of the CA Mainframe Application Tuner (CA MAT):
The client was interested in finding out where the CICSGLBL parms were loaded from.
1. They changed UTRPARM(CICSGLBL) MONITOR from YES to NO and reran the TUNS transaction in a CICS region. Nothing changed, it stayed YES.
2. They then recycled the CA MAT address space and again ran the TUNS transaction with no change, it stayed YES.
3. They then recycled CICS and the PLT ran and the region came up with Monitor=NO, it changed to NO.
4. They then reran the CICS transaction TUNS and the TDQ showed Monitor=YES.
Here was their question: They want to know what is in place that allowed Monitoring to go back to YES if it was coded in CA MAT as NO and a recycle of CICS was also NO but when TUNS was entered it changed to YES?
Said another way: What has to be done if we don't initialize CA MAT from the CICS PLT?
Instructions:
From the list of scenarios in the Summary above:
1. When CICS region starts with PLT (TC00CPLT) and without SIT parameter
r'INITPARM=(TCnnFSET='SERVERID=xxxxxxxx')
where 'nn' is CICS release number
'xxxxxxxx' is the MAT server name that it will get the CICS parameter
or with SIT parameter
'INITPARM=(TCnnFSET='SERVERID=xxxxxxxx')
but MAT server is not ACTIVE, internal programmatic CICSDFLT parameters are used.
The DEFAULT values are:
MONITOR=YES
MAXTRANS=2000
RESET_TRAN=TUNS
COLLECT_TRAN=TUNC
COLLECT=1
The messages in CICS MSGUSR would indicate it is 'CICSDFLT'.
2. When CICS region starts with PLT (TC00CPLT) and with SIT parameter
'INITPARM=(TCnnFSET='SERVERID=xxxxxxxx')
where 'nn' is CICS release number
'xxxxxxxx' is the MAT server name that will get the CICS parameter
and MAT server is ACTIVE
and MAT server start with CICSGLBL
and there is no entry in CICSREGN for this CICS region
The values in CICSGLBL will be used and the messages in CICS MSGUSR would indicate it is 'CICSGLBL'.
3. When CICS region start with PLT (TC00CPLT) and with SIT parameter
'INITPARM=(TCnnFSET='SERVERID=xxxxxxxx')
where 'nn' is CICS release number
'xxxxxxxx' is the MAT server name that it will get the CICS parameter
and MAT server is ACTIVE
and MAT server start with CICSGLBL
and there is a matching entry in CICSREGN for this CICS region
The values in CICSREGN will be used.
The messages in CICS MSGUSR would indicate it is 'CICSREGN'.
4. When CICS region start without PLT (TC00CPLT) and later would like to START CA MAT CICS exits, enter 'TUNS' (RESET TRAN) on a CICS terminal would set CICSDFLT parameter values.
enter 'TUNS serverid' on a CICS terminal would set parameters from this MAT 'serverid'
5. If CICS started with a set of parameter values and would like to change afterwards, you can change the parameters either in CICSREGN or CICSGLBL:
recycle MAT server,
enter 'TUNS serverid' on a CICS terminal
This would set parameters from this MAT 'serverid'. There is no need to recycle CICS. After you change the parameters and recycle CA MAT server, you can enter 'TUNS serverid' on a CICS terminal. This will change the parameter without a recycle of CICS.
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Hung-Che
Published
Facemask ATM + Reminder
Fear not ol' forgetful geezers for I have a solution for the ever-existing problem in these pandemic time of forgetting face mask!!
BeginnerShowcase (no instructions)58
Facemask ATM + Reminder
Things used in this project
Story
Read more
Code
Face mask ATM
Arduino
#include <LiquidCrystal.h>
#include <Keypad.h>
LiquidCrystal lcd(12,11,A4,A5,13,10);
const byte ROWS = 4;
const byte COLS = 4;
const int pirPin = A3;
char keys[ROWS][COLS] = {
{'7','8','9','C'},
{'1','2','3','A'},
{'4','5','6','B'},
{'*','0','#','D'}
};
byte rowPins[ROWS] = { 2, 3, 4, 5 };
byte colPins[COLS] = { 6, 7, 8, 9 };
Keypad kpd = Keypad( makeKeymap(keys), rowPins, colPins, ROWS, COLS );
int fm = 0;
void setup() {
Serial.begin(9600);
lcd.begin(16, 2);
pinMode(pirPin, INPUT);
}
void loop() {
//case 1: when there is no face mask
int fm_temp = 0;
while(fm==0){
lcd.setCursor(0,0);
lcd.print("Number of mask:");
lcd.setCursor(0,1);
lcd.print("Max 100: ");
//input number of face mask
char key = kpd.getKey();
if(key){
if(key == '0') fm_temp = fm_temp * 10 + 0;
if(key == '1') fm_temp = fm_temp * 10 + 1;
if(key == '2') fm_temp = fm_temp * 10 + 2;
if(key == '3') fm_temp = fm_temp * 10 + 3;
if(key == '4') fm_temp = fm_temp * 10 + 4;
if(key == '5') fm_temp = fm_temp * 10 + 5;
if(key == '6') fm_temp = fm_temp * 10 + 6;
if(key == '7') fm_temp = fm_temp * 10 + 7;
if(key == '8') fm_temp = fm_temp * 10 + 8;
if(key == '9') fm_temp = fm_temp * 10 + 9;
if(key == 'A') fm_temp = fm_temp / 10;
lcd.setCursor(9,1);
lcd.print(fm_temp);
lcd.print(" ");
if(key == 'D'){
//if number exceeds 100, reset fm to -1
if(fm_temp > 100){
fm = -1;
}else{
fm = fm_temp;
}
fm_temp = 0;
}
}
}
//case 2: when there is one or more face mask
while(fm>0){
lcd.setCursor(0,0);
lcd.print("Current amount:");
lcd.setCursor(0,1);
lcd.print(fm);
lcd.print(" ");
//algorithm for each time motion sensor detects something
int pirStat = digitalRead(pirPin);
if(pirStat == HIGH){
Serial.print("I got chu");
tone(A1, 100, 500);
delay(5000);
if(fm > 1){
fm--;
}else if(fm == 1){
fm = -2;
}
}
}
//case 3: when fm exceeds 100 and need to be reset
while(fm==-1){
lcd.setCursor(0,0);
lcd.print("Invalid number!");
lcd.setCursor(0,1);
lcd.print("Any key to redo ");
char key = kpd.getKey();
if(key){
fm = 0;
}
}
//case 4: when fm runs out and needs to be refilled
while(fm ==-2){
lcd.setCursor(0,0);
lcd.print("Out of facemask!");
lcd.setCursor(0,1);
lcd.print("Any key to input");
char key = kpd.getKey();
if(key){
fm = 0;
}
}
}
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Hung-Che
Hung-Che
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High School Junior
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A consistent long-lasting pattern of spatial variation in egg size and shape in blue tits (Cyanistes caeruleus)
Abstract
Background
Interspecies variation in avian egg shape and size is understandable in terms of adaptation, allometry and phylogeny. Within-species variation in egg properties influences offspring fitness and can be explained by differences in allocation of resources into reproductive components of life history in mulidimensionally variable environments. Egg size is inherently traded-off with clutch size, which may also be true of egg shape in some cases. We investigated long-term variation in egg shape and size between two geographically close populations of blue tits Cyanistes caeruleus in relation to clutch size and habitat differences.
Results
The main finding is that there exists a persistent long-lasting pattern of spatial variation of egg size and shape between the two study populations of blue tits, 10 km apart, controlling for clutch size. Eggs in the urban park site were on average larger in volume and less spherical in shape than eggs in the forest site over 12 years of this study. Egg sizes were negatively associated with clutch sizes. Egg shape was not correlated with clutch size.
Conclusions
Our findings suggest that the pattern of variation in egg size and shape results from different trophic richness of the breeding habitats of the study populations, demanding different allocation of resources and, especially, from the contrasting difference in the availability of calcium.
Background
The avian egg is an evolutionarily elaborated version of the eggs of amniotes, in general, and the eggs of theropods, in particular [1]. In addition to containing the genetic equipment, it stores all the nutrients needed by the embryo to develop successfully [2]. At the level of class Aves, egg sizes are allometrically related to female body sizes, yet the relationship shows some differences between taxa and modes of development within birds [3]. Also the shape of bird eggs shows remarkable taxonomic diversity, with characteristic phylogenetically constrained patterns [2, 4, 5]. Inter-species variation in egg shape was found to be associated with avian flight adaptations [4], which, however, does not explain within-species variation. It seems reasonable to consider within-species variation in egg size as part of reproductive allocation strategy and seek its explanation within the framework of life-history theory [6].
Within species, different measures of nestling/fledgling performance, such as rates of growth and development, hatchability and chances to fledge, are usually positively affected by egg sizes [7, 8], at least to some threshold egg size, above which nestling performance increases no further [9]. In optimal environmental conditions birds would be expected to lay eggs of minimum size which still maximizes chances of nestling survival. Although producing eggs smaller than that size would be costly in terms of fitness, the negative effects can be overridden by parental care of nestlings, especially by adequate feeding [9, 10] which may be possible if the nestling stage coincides with the time of rich food abundance. If the amount of energy and nutrients allocated to a single egg affects not only its own size, but also the size of the subsequent eggs in a clutch, a trade-off between egg size and clutch size should arise because it is ultimately the number of surviving offspring which is the currency of fitness [6, 11, 12]. Optimal allocation of resources into individual eggs in the whole clutches is a key component of reproductive strategy that is certainly dependent on resource richness in the breeding habitat [6]. Because resources, including macronutrients and micronutrients, tend to be limited and variable in time and space (habitat), constraints on optimal allocation arise, and, therefore, some level of plasticity is favoured by natural selection [13]. Fitness may be locally maximised by different, resource-dependent allocation, resulting in producing clutches and eggs of different size in different habitats.
Egg shape is not usually considered in the context of intraspecies life-history variation, but it was hypothesised that optimal shape should depend on the number of eggs in the clutch in view of the way eggs are incubated [14]. Eggs of optimal shape should best fit the brood patch of incubating parents to be most efficiently maintained at an appropriate level of temperature for embryos to develop, resulting in clutches of different size having different optimal shapes of eggs [14]. In the case of larger clutches, it is not possible for all eggs to be in contact with the brood patch at the same time because they are distributed in layers within the nest cup and must be systematically rearranged to be uniformly warmed [15, 16]. If there is an optimal clutch-size-dependent shape of eggs, a pattern of relationship between egg shape and clutch size should be observable in avian populations because deviations from the optimal shape would be selected against [17]. In a study on fitness consequences of variation in egg shape in common blackbirds Turdus merula and great tits Parus major Encabo et al. [17] did not find any relationship between egg shapes and clutch sizes. This suggests that some other factors, perhaps limiting resources needed by females during the process of egg formation, should be taken into consideration. Calcium is a micronutrient whose availability is known to be often limiting for breeding birds during the stage of egg formation and nestling growth [7, 18,19,20,21,22]. Calcium availability seems to be able both to modify optimality criteria for egg shape and to generate its own selection pressures on egg shape and size.
The structure of eggshell is critically important for an avian embryo to develop normally into a hatchling that would have a chance to survive to fledging and then to the reproductive maturity [7, 22]. The shell must meet physiological functions associated with the embryo’s water management and gas exchange during incubation, which takes place in a nest containing the whole clutch. Hence it must be strong enough for eggs not to be damaged in the crush from incubating adults and other eggs. In fact, the shell must be produced quickly, in passerine in 1 day, and for just one egg at a time, because of egg fragility and bird mobility, with flight being especially prone to cause egg damage [2, 4]. In most small passerine birds eggshells are formed on the basis of the daily income of calcium, with no stored reserves available [7]. The availability of calcium may constrain a possibility of forming eggs of most profitable size in terms of fitness, which may generate selection pressures on the most compact and strong shapes. These factors may influence a balance between egg size and clutch size. In general, as economical a use of calcium as possible would be expected in calcium-poor habitats, where even defective eggshells are regularly recorded [18]. Calcium-poor habitats with otherwise good trophic conditions for breeding may generate selection for locally adaptive sizes and shapes of eggs as well as clutch sizes.
This study concerns blue tits Cyanistes caeruleus breeding in two areas that are contrastingly different in habitat properties, especially in terms of trophic conditions [23] and in terms of calcium availability [24]. One site is rich in caterpillars, the optimal food of nestlings, but poor in calcium, whereas the other site is poor in caterpillars, but rich in calcium [23, 24]. Bańbura et al. [24] revealed that eggs laid by blue tits in the calcium-poor area are on average smaller than in the calcium-rich area, with clutch sizes being larger in the former than in the latter. In this study we analyse a much larger dataset collected over 12 years of breeding. In particular, we focus on egg shape as well as on egg size. If the inter-habitat difference in egg traits resulted only from the association with clutch size, it should disappear after statistically correcting for variation in clutch size. If the difference remains after the adjustment, it must result from properties of the habitats compared. We expect that eggs should be not only smaller on average, but also more spherical in the calcium-poor area because round eggs make more economical use of calcium [14].
The aims of this study are to:
1. 1.
check if variation in egg volume between two spatially close populations of blue tits represents a consistent long-term pattern.
2. 2.
test if there exists any consistent pattern of variation in egg shape.
3. 3.
examine if variation in egg size and shape is associated with clutch size.
Methods
Study sites
This study was carried out between 2002 and 2013 as part of a long-term research project on the breeding biology of nestbox breeding populations of hole-nesting birds in two study sites within and near Łódź, central Poland. The study sites represent structurally different habitats of an urban parkland and a deciduous forest, 10 km apart. The urban park site (51°45’N; 19°24′E) is an 80 ha area that is composed of the zoological and botanical gardens, located in the SW part of the city of Łódź. The forest study site (51°50’N; 19°29′E) is a 130 ha area in the interior part of a mature mixed-deciduous forest (Łagiewniki Forest; 1250 ha in total), bordering on the NE suburbia of Łódź. The tree cover of the park area is highly fragmented and arranged to be useful for the purpose of animal and plant exposition, with trees constituting a mixture of many exotic and native species, deciduous and coniferous. This study site has a lot of open space, pathways, fences and buildings. Predominating tree species in the forest study area are pedunculate oaks Quercus robur and sessile oaks Quercus petraea. The tree canopy of this area is almost continuous and it also covers most of a small number of pathways crossing the forest.
Some characteristics of the study sites influence the availability of calcium for laying females. In the Łagiewniki Forest as a whole, including the study area, there has been a long-term tendency for water bodies and streams to dry up over the last 30–40 years. Water bodies in the urban park site are stabilised by artificial supply of water and, in addition, considerable parts of this area are watered as part of plant growing procedures. Soils of the Łagiewniki Forest are acidic, with pH < 5, whereas in the park site pH is higher (pH > 6) [25]. There are many artificial sources of calcium in the park area (lime, grit, buildings, pathways and so on), whereas such sources are lacking in the forest. The assemblage of shelled snails during the time of this study in the park site contained abundant synanthropic species, such as Arianta arbustorum, Cepaea nemoralis, and Punctum pygmaeum, which are completely absent from the forest [24]. Density of shelled snails is several times lower in the forest than in the park site [24].
Wooden nestboxes with a removable front panel [26] were erected on trees at a height c. 3 m above the ground level in both the study sites, c. 200 in the urban park site and 300 in the forest site. The nestboxes were distributed in a grid, keeping a distance of about 50 m between them. Mean density of nestboxes was similar in both study sites, 2.2–2.3 per 1 ha [27].
Egg data
The field procedure in our study routinely starts in early spring (late March) from inspections of nestboxes to find signs of nest building and to determine nesting species. Then study sites are visited daily to record clutch initiation dates and clutch sizes in occupied nestboxes. Measurements of length and breadth of each egg in all clutches were taken with dial sliding calipers to the nearest 0.1 mm. Accidentally, eggs in a small fraction of clutches were not measured for technical reasons. This study is based on 8572 (3445 in the park site and 5127 in the forest site) eggs from 781 complete clutches (322 in the park site and 781 in the forest site) of blue tits measured over 12 years.
Based on lengths (L) and breadths (B) of individual eggs, volume (V) was calculated applying Hoyt’s [28] formula, V = 0.51 * L * B2 and shape (sphericity index, SH) was calculated according to the formula, SH = (B/L) * 100 [17, 29]. The B/L index is the reciprocal of the L/B index [29], thus indicating egg sphericity, which increases with egg breadth increasing in relation to egg length. These indices of individual egg shape and volume were data points analysed in this study.
Statistical analyses
Because eggs in clutches tend to be similar in size to each other, their measurements cannot be treated as independent data records [30]. Accordingly, we calculated the intra-clutch repeatability of egg volume and egg shape for the whole data set, applying the intra-class correlation based on variance components obtained from one-way anovas [30], with standard errors estimated following Becker [31].
Egg volumes and shapes were analysed as dependent variables in separate linear mixed models in relation to year and site factors and clutch size as a covariate. Modeling started from models that included the first order interactions between all of the independent variables; non-significant interactions were deleted to leave the final model containing only significant interactions and all independent variables [32]. Clutch ID was included as a random effect in the models to control for clustering that resulted from eggs being laid in clutches (thus lacking independence from those in the same clutch), which was associated with degrees of freedom being estimated using the Satterthwaite method [33]. Statistical computing was performed using IBM SPSS Statistics 22 [33].
Results
Both egg volume and shape show high variation between clutches and low variation within clutches, resulting in substantial repeatability (egg volume: R = 0.782 ± 0.027 (SE), F780;7791 = 40.1, p < 0.0001 and egg shape: R = 0.714 ± 0.026 (SE), F780;7791 = 40.1, p < 0.0001).
Egg volume
The most striking result concerning egg volume in the study populations of blue tits was that the eggs showed a consistent pattern of variation between sites. Eggs in the urban park site were on average 5% larger than eggs in the forest site every year of the study (total mean volumes: 1.181 cm3 ± 0.005 (SE) v. 1.124 cm3 ± 0.004 (SE)). The data were modeled using two separate models. In the first model, which included year as categorical variable (12 years), neither effects of the two-way interactions nor of the year factor were significant (Table 1, Fig. 1). The site factor and the clutch size covariate had significant effects on egg volume, with the effect of clutch size being negative (Table 1, Fig. 2). The second model treated year as a continuous variable (Table 1). Because effects of the two-way interactions were non-significant in this model either, the main effects could be considered separately. While the effect of site remained highly significant, a significant negative effect of years was also revealed, with the clutch size covariate being non-significant (Table 1). This means that the eggs of the blue tits studied tended to reduce in size over time and that the tendency was consistently parallel in the two populations (Fig. 1).
Table 1 Summary of linear mixed models of egg volume of blue tits in relation to year, site and clutch size. Two separate models are shown: (i) with year as a categorical factor and (ii) with year as a continuous variable. Clutch ID included as a random effect
Fig. 1
figure 1
Mean volumes of blue tit eggs in the urban parkland site (squares) and the forest study site (triangles) during 2002–2013. Means ± standard errors are given
Fig. 2
figure 2
Relationship between the per-clutch mean egg volume and clutch size for 781 clutches of blue tits
Egg shape
Since the egg shape measure used in this study might not be independent of egg volume, the models examining egg shape included egg volume as a covariate in addition to year, site, clutch size and all two-way interactions. Two separate models were considered: the first one treated year as a categorical factor, while the second one included year as a continuous covariate (Table 2). Both final models showed a very similar pattern with a significant effect of the site – egg volume interaction (Table 2). This interaction in both the models resulted from egg sphericity being negatively correlated with egg volume in the forest site, but not in the urban park site (Table 2). The effect of site was not entangled in any interactions and, hence, was considered separately, showing a significant variation between the two study populations (Table 2, Fig. 3). Eggs were slightly more spherical in the forest population than in the urban park population (total mean sphericity: 76.992% ± 0.149 (SE) v. 76.026% ± 0.161 (SE), respectively). No differences in egg shape among years nor any trend over time were found (Table 2). Egg shape was not found to be dependent on clutch size (Table 2).
Table 2 Summary of linear mixed models of egg shape (sphericity) of blue tits in relation to year, site, clutch size and egg volume. Two separate models are shown: (i) with year as a categorical variable and (ii) with year as a continuous variable. Clutch ID included as a random effect
Fig. 3
figure 3
Mean shape indices of blue tit eggs in the urban parkland site (squares) and the forest study site (triangles) during 2002–2013. Means ± standard errors are given
Discussion
This study found that egg shape as well as egg size may differ between spatially close populations of a small passerine. The main finding is that there exists a persistent long-lasting pattern of spatial variation of egg size and shape between the two study populations of blue tits, 10 km apart. Eggs in the urban park site were on average larger in volume and less spherical in shape than eggs in the forest site. Egg volume tended to decrease over the years in parallel between the urban park and the forest. We found no year-to-year variation in the case of egg shape.
Offspring size and number during particular breeding attempts as well as over the whole reproductive life of the individual are fundamental life-history traits [6]. The trade-off between egg size and clutch size in birds is a particular case of a more general pattern of trade-off between offspring size and number that is inevitable when the limited resources are allocated between individual offspring in a particular breeding attempt [6, 11, 34]. In wild bird populations living in heterogenous environments the negative relationship between egg size and clutch size expected from the trade-off may be masked by the effect of female (pair) body condition, where high condition females are capable of laying both big eggs and big clutches [35, 36]. The model of Charnov et al. [12] proposes that in the case of birds that produce relatively big clutches, such as tits (Cyanistes, Parus) or flycatchers (Ficedula), the masking effect may be weaker than in species laying clutches of smaller size. Accordingly, a significant negative correlation is usually found in species laying larger clutches [37,38,39,40]. In our study we also found such a significant negative correlation in blue tits.
Our study, based on individual eggs, controlling for clustering in clutches, considers egg shape (sphericity) as well as egg size (volume). Both egg volume and shape proved to be highly repeatable within clutches, which is typical of birds [24, 30]. Egg indices of both size (volume) and shape (sphericity) are derived from the basic linear measurements of eggs that are routinely taken in the field [28, 29]. Adamou et al. [41] have recently shown that these indices are good approximations of principal component measures of size and shape of eggs. However, in contrast to principal component indicators of shape, the measures of shape derived from egg linear dimensions, including the index of sphericity used in this study, may not be independent of egg volume. To control for this lack of independence, we used egg volume as a covariate in models explaining egg shape. The difference in average egg sizes between the blue tit populations nesting at the park site and the forest site for 2002–2009 was shown by Bańbura et al. [24]. Their analysis was based on per-clutch mean volumes and linear dimensions of a sub-set of the whole egg dataset. Our present findings more powerfully confirm the existence of a stable, long-lasting pattern of difference in egg volume and, in addition, in egg shape between the study populations inhabiting the urban park site and the forest site. We found that egg volumes significantly decreased over the years in a parallel manner in both the study sites. No consistent change over time was found in the case of egg sphericity.
Inter-annual, usually rather slight variation in egg size has been reported for many species of birds [41,42,43]. It was suggested that under current global warming, some trends in inter-annual variation in egg traits might be expected in different bird species [44], which in fact came true in several cases, yet sometimes trends were in an unexpected direction [45,46,47]. The latter is also the case in our present study, where we found a decreasing trend in egg volumes instead of an increasing trend that would be expected from earlier arguments [44]. In agreement with the global trend, air temperature in Poland, from the scale of the whole country to the local scale of our study area, is known to have been increasing over the last hundred years [48]. This increase manifests itself in both annual mean temperatures and in spring temperatures, resulting, however, not only in warming, but also in more frequent and less predictable extreme weather events [48], which may not be favourable to breeding birds. As far as we know, no data on inter-year variation in egg traits of blue tits are available in the literature, whereas there are a few reports concerning different populations of another parid species, the great tit. Jarvinen and Pryl [49] found no differences between years in egg volumes or linear dimensions in a south Finland population of this species. Slight inter-year variation in egg size and shape, entangled in interactions of the year factor with other factors, was reported by Ojanen et al. [50] for north Finland. Hõrak et al. [51] found significant year-to-year variation in egg volume and shape, with no clear pattern, in rural and urban populations of great tits in Estonia; a significant difference in egg volume between 2 years was also shown by Mӓnd et al. [52] in the same country. The differences most probably result from effects of year-to-year differences in ecological conditions prevailing during the time of egg formation on resource allocation between egg size and clutch size [9, 46, 53].
Spatial variation in egg volume and linear dimensions was analysed on the scale of entire Europe in the case of great tits, but not blue tits [54]. Small-scale spatial or habitat effects were also more often studied in great tits. Hõrak et al. [51] showed that eggs in an urban park site in Tartu, Estonia, were on average smaller than in a rural forest site (the distance between the study sites c. 5 km). By contrast, Riddington and Gosler [55] found that great tit eggs in Oxfordshire village and urban gardens were heavier (larger) than in the forest habitat of Wytham Wood (the distance between the gardens and Wytham Wood c. 2 km). Mӓnd et al. [52] reported that eggs in the deciduous forest site tended to be larger than eggs in the coniferous forest site in Estonia (the study sites to c. 10 km apart). Hargitai et al. [56] discovered that eggshells in an urban park were thicker than in a woodland site in great tits (the distance between the sites c. 20 km). Slight variation in egg size [57] and shape [58] was shown to be related to the altitude of nest sites in ultramarine tits (African blue tits) Cyanistes teneriffe ultramarinus in Algeria. In our study populations we previously found a significant between-habitat difference in mean egg sizes of blue tits, but no of great tits [24]. This difference in the patterns of egg size and shape variation between the tit species is confirmed by the present study on blue tits and our new data on great tits (in preparation). A very similar pattern of inter-habitat variation in egg volume was revealed for the same tit species in Burgundy, with no difference in great tits and a significant difference in blue tits, and with eggs being larger in urban habitats than in the forest (the study sites 40–100 km apart) [59]. Apart from our study, we are not aware of any other results describing clear patterns of variation in egg shape as well as egg size between habitats in European blue tits. The persistent difference in egg size and shape between sites with parallel fluctuations across the years of the study suggest that there exists a long-lasting difference between the sites, on the one hand, and a cause of year-to-year variation which is common for the two sites, on the other hand.
The basic idea behind our study system was to encompass study sites of contrasting habitats to be studied in a long-term perspective. As a consequence, we established our nestbox study areas in a large urban park habitat and in an interior part of a deciduous forest, assuming that the former would represent a sub-optimal habitat, while the latter would be the optimal habitat for nesting tits. The breeding density of blue tits is variable over the years, and with the grand mean values of 3.4 pairs/10 ha in the forest and 3.8 pairs/10 ha in the park, it is relatively low in comparison with the values typical of West European populations of this species [40], which is also true of great tits (own data). We estimate that 90–95% of breeding pairs of both tit species nests in nestboxes, even if both study sites are also rich in natural holes. Thus, the potential nest sites are superabundant. Of the available nestboxes, no more than 35% are occupied by all hole-nesting species in the forest site, with the corresponding figure for the park site being 60%, still leaving many holes free. The age structure seems not to much differ between the forest and the park populations – the proportion of the first-year adults is 41–44% against 56–59% of older adults in both the sites (own data, in preparation). The blue tits are typically single-brooded, with very rare, exceptional second breeding attempts.
In terms of the abundance of leaf-eating caterpillars, as key food for nestlings, the contrast between the forest and the urban park study sites is considerable. The leaf-eating caterpillars are on average three times more abundant in the forest site than in the park site, which leads to the corresponding difference between the sites in their suitability for rearing nestling tits [23, 27, 60, 61]. It is well known that tits and some other insectivorous species lay larger clutches in optimal habitats than in suboptimal ones because clutch size tends to be adjusted to the trophic conditions during the chick-rearing phase [9, 62,63,64,65].
In accordance with the difference between our study sites in the abundance of caterpillars, clutches of blue tits are on average larger in the forest site than in the urban park area, with some variation between years occurring [23, 60]. In fact, it is not only the abundance of leaf-eating caterpillars that differs between the two study sites. Insects and other arthropods in general are distinctly more abundant in the forest site than in the urban park site [66, 67], which creates more favourable trophic conditions for breeding insectivorous birds. On the other hand, the forest site is characterised by a five to six times lower density of shelled snails than the urban park site, with the latter area being home for abundant human-associated snails, such as Cepaea spp. [24]. It was shown by many authors that poor availability of shells and other sources of calcium is limiting for females during the time of egg formation, when the demands for calcium are highest [18, 19, 53, 68]. We suggest that this is also the case with blue tits in our forest study site. High availability of insect food and poor availability of calcium may maintain a pressure on females to move a balance in resource allocation towards producing smaller eggs because any potential initial disadvantages can be compensated for at the nestling stage. When considered separately in field experiments on blue tits in Scotland, the quality of supplemental food had positive effect, whereas supplemental calcium had no effect on egg sizes [69, 70]. Obviously, the experimental supplements used by Ramsay and Houston [69, 70] were transient factors, while the trophic characteristics of our study sites are enduring factors, both of which can have effects on egg size but at a different level. Transient factors may result in a release from trophic limitation, when supplementary food and/or micronutrients are provided, or in the limitation becoming even more severe, when the resources are reduced. Enduring factors generate selection pressures for economical use of resources, which can run adaptive changes in female physiology and oviduct morphology [4], resulting in producing smaller ova, needing less calcium. Transient factors would be expected to determine rather eggshell thickness than egg size or shape.
The difference in clutch size between our study sites may suggest that smaller mean egg sizes in the forest site than in the urban park site could potentially result just from different allocation of resources. However, we excluded such an effect in statistical analysis by including clutch size as a covariate in the models. Thus, the persistent difference in egg sizes between the study populations was shown to be independent of clutch size, which suggests that blue tits in the forest site lay smaller eggs than expected from their clutch size and from the respective trade-off between egg size and clutch size in comparison with the urban park site. Eggs laid in the forest site are not only smaller than eggs in the park site, but also tend to be more round, with roundness being the most calcium-saving shape of eggs [14]. Moreover, the eggs tend to become less spherical with the increasing volume in the forest, while no such tendency occurs in the park.
In contrast to egg sizes being related to clutch size, we found no correlation between egg shape and clutch size. We expected that such a correlation should occur in blue tits. Because blue tits lay some of the largest clutch sizes of any passerine [40] and a clutch in our study populations is on average composed of over 11 eggs [27], the eggs must be arranged in layers within the nest cup. As a consequence, to expose all eggs of a clutch to an appropriate temperature during incubation, females rotate and rearrange them regularly to enable them to be uniformly warmed by the brood patch, to allow air to circulate around eggs, and to dissipate heat when the eggs are too warm [14, 15, 17, 71, 72]. The physical shape, considered along the roundness-elongation axis, may directly influence feasibility of getting a space-saving arrangement of eggs within the whole clutch, which should be also affected by clutch size [14, 17]. It seems reasonable to expect that from the point of view of the space-saving three-dimensional arrangement of eggs in the space of nest cup, larger clutches should contain more elongated eggs. However, the acts of rotation and rearrangement of eggs by incubating females may expose eggs to elevated risks of breakage. They may be greater with increasing clutch size and with declining calcium availability. On the other hand, more spherical eggs form a stronger structure for a given, limited amount of calcium [14]. All this may account for our results that eggs in the forest site are more spherical than eggs in the urban park site and that it happens at least in some years that egg sphericity is positively related with clutch size. Analogously, Kouidri et al. [58] found that egg sphericity in North African ultramarine tit tended to increase with clutch size at high altitude, where ecological conditions were harsh. Gosler et al. [73] found that great tit eggs were more spherical in calcium-poor surroundings.
Thus, the patterns in egg shape variation seem to complement the pattern of variation in egg sizes in the study populations of blue tits. They both support the hypothesis that the availability of calcium may be the most important factor that affects variation in egg size and shape, resulting in the existence of stable spatial patterns. Under poor calcium availability, females would be expected to lay smaller and more spherical eggs than under rich calcium availability.
Conclusions
We found in this study that both egg size and shape show consistent patterns of variation between two spatially close populations of blue tits. The difference in egg volumes between the two sites goes beyond the difference expected from the trade-off with clutch size, which is also true of egg shape. Overall, the patterns of variation in egg traits we found and their stability over time suggest that there may be different optimal sizes and shapes of eggs between the caterpillar-rich-calcium-poor habitat and the caterpillar-poor-calcium-rich habitat.
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Acknowledgements
We thank E. Wróblewska, A. Jaksa, D. Mańkowska and J. Białek for their help and consent to conducting research in the areas under their administration. We thank A.P. Cowie for linguistic consultation. Critical comments of two anonymous referees greatly helped us revise the manuscript. We are very grateful to them.
Funding
The study was financially supported by the University of Łódź.
Availability of data and materials
The datasets used and analysed during the current study are available from the corresponding author on reasonable request.
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MB and JB carried out the analyses and drafted the manuscript. JB and PZ designed the study. MB, MG, AK, MM, JS, JW, PZ and JB conducted the field study. MG, AK, MM, JS, JW and PZ improved several subsequent versions of the manuscript. All authors read and approved the final manuscript.
Corresponding author
Correspondence to Jerzy Bańbura.
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The field study and all procedures were performed under the licenses from The General Directorate for Environmental Protection, The Regional Directorate for Environmental Protection in Łódź, The Local Ethical Committee for Research on Animals and Polish Bird Ringing Centre.
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Bańbura, M., Glądalski, M., Kaliński, A. et al. A consistent long-lasting pattern of spatial variation in egg size and shape in blue tits (Cyanistes caeruleus). Front Zool 15, 34 (2018). https://doi.org/10.1186/s12983-018-0279-4
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• DOI: https://doi.org/10.1186/s12983-018-0279-4
Keywords
• Egg shape
• Egg volume
• Life history
• Passerine
• Spatial variation
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1. Advanced Patent Search
Publication numberUS6942158 B2
Publication typeGrant
Application numberUS 10/697,011
Publication dateSep 13, 2005
Filing dateOct 31, 2003
Priority dateNov 21, 2002
Fee statusPaid
Also published asDE10353373A1, DE10353373B4, US20040099738
Publication number10697011, 697011, US 6942158 B2, US 6942158B2, US-B2-6942158, US6942158 B2, US6942158B2
InventorsJohn Deryk Waters
Original AssigneeHewlett-Packard Development Company, L.P.
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Memory tag and a reader
US 6942158 B2
Abstract
A memory tag comprising a resonant circuit part, a memory, a detector module and an output generator module, the resonant circuit part being operable to generate an output signal in response to a signal from a reader, the amplitude of the output signal dependent on the magnitude of the signal from the reader, the detector module being responsive to the magnitude of the output signal such that, when the magnitude of the output signal is relatively low, the detector module causes the output generator module to transmit an identifier signal, and when the magnitude of the output signal is relatively high, the detector module connects the memory to the resonant circuit part.
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Claims(28)
1. A memory tag comprising a resonant circuit part, a detector module and an output generator module, the resonant circuit part being operable to generate an output signal in response to a reader signal from a reader, the magnitude of the output signal being dependent on the magnitude of the reader signal, the detector module being responsive to the magnitude of the output signal such that, when the magnitude of the output signal is relatively low, the detector module causes the output generator module to transmit an identifier signal which is configured to cause the reader to increase the magnitude of the reader signal from a first level to a second relatively high level, and when the magnitude of the output signal is relatively high as a result of the tag receiving the second relatively high magnitude reader signal from the reader, the detector module is operable to cause the tag to move to an operating mode.
2. A memory tag according to claim 1 comprising a memory, wherein the detector module is operable in response to the reader signal being at the second relatively high level, to cause the tag to move to the operating mode by connecting the memory to the resonant circuit part.
3. A memory tag according to claim 1 comprising a rectifying circuit part responsive to the output signal of the resonant circuit part to generate an output voltage, and wherein the detector module is responsive to the magnitude of the output voltage.
4. A memory tag according to claim 3 wherein the tag comprises a memory and wherein the detector module is operable to move the tag to an operating mode by connecting the memory to the rectifying circuit part when the output signal is relatively high, and operable to disconnect the memory from the rectifying circuit part when the magnitude of the output signal is relatively low.
5. A memory tag according to claim 1 wherein the resonant circuit part comprises a switch, wherein when the magnitude of the output signal is relatively low the output generator module is operable to control the switch to transmit the identifier signal, and when the magnitude of the output signal is relatively high, the memory is operable to control the switch.
6. A memory tag according to claim 1 wherein the output generator module comprises a pseudorandom binary sequence generator to generator an identifier signal comprising a pseudorandum binary sequence.
7. A memory tag according to claim 1 wherein the resonant circuit part is operable to provide inductive coupling to a reader wherein the reader signal is received via the inductive coupling.
8. A memory tag comprising a resonant circuit part, a detector module, an output generator module and a memory, the resonant circuit being operable to generate an output signal in response to a reader signal from a reader, the magnitude of the output signal being dependent on the magnitude of the reader signal, the detector module being operable in response to the output signal such that when the magnitude of the output signal received by the memory tag is relatively low, the detector module causes the output generator module to transmit an identifier signal configured to induce the reader to increase the magnitude of the reader signal from a normal finite level to a higher level, and when the magnitude of the output signal is relatively high in response to the magnitude of the reader signal being increased to the higher level, the detector module is operable to connect the memory to the resonant circuit part.
9. A reader to read a memory tag, the reader being operable to transmit a reader signal to a memory tag, the reader further being operable to receive a signal from a memory tag, the reader:
being operable to transmit the reader signal to the memory tag at a first, relatively low power, and in response to an identifier signal being issued from the memory tag in response to receipt of the reader signal having the first relatively low power, and
being operable to transmit a reader signal to the memory tag at a second, relatively high power whereby the reader is switched from a low power search mode to a high power read mode.
10. A reader according to claim 9 comprising a resonant circuit part and a signal generator operable to supply a drive signal to the resonant circuit part, the reader further comprising an amplitude modulator to control the amplitude of the drive signal supplied from the signal generator to the resonant circuit part.
11. A reader according to claim 9 comprising a output signal identifier module, operable to identify the identifier signal from the memory tag.
12. A reader according to claim 11 wherein the reader comprises a correlator operable to identify the identifier signal.
13. A reader according to claim 9 operable to provide inductive coupling to the memory tag wherein the reader signal is transmitted via the inductive coupling.
14. A reader to read a memory tag, the reader comprising a resonant circuit part, an interrogator, and an identifier signal module, the interrogator module being operable to transmit a reader signal at a first, relatively low power to a memory tag, receive a signal from the memory tag which is generated by the memory tag in response to receipt of the first, relatively low power reader signal, and pass the received signal to the identifier signal module, the identifier signal module being operable to identify the identifier signal and generate an instruction to the interrogator module to generate a reader signal at a second, relatively high power.
15. A system comprising a memory tag and a reader, the memory tag having a resonant circuit part, a detector module, an output generator module and a memory holding data, the reader comprising a resonant circuit part operable to transmit a reader signal to the memory tag and receive a signal from the memory tag, the reader being operable to transmit a reader signal to the memory tag at a first relatively low power wherein,
the resonant circuit part of the memory tag, in response to the reader signal, generates an output signal having a first, relatively low magnitude,
the detector module is responsive to the first relatively low magnitude of the output signal to cause the output generator module to transmit an identifier signal,
the reader is operable to receive the identifier signal from the memory tag and identify the identifier signal, and generate a reader signal at a second, relatively high power,
the resonant circuit part of the tag is operable to generate an output signal having a second, relatively high magnitude, the detector module being responsive to the output signal having a second, relatively high magnitude to connect the memory to the resonant circuit part, and
the memory tag is operable to send a signal to the reader to transmit the data held in the memory to the reader.
16. A method of operating a memory tag comprising the steps of detecting a reader signal received from a reader, and, when the magnitude of the reader signal received by the tag is relatively low, transmitting an output identifier signal from the tag to the reader to induce the reader to increase the power of the reader signal, and when the magnitude of the reader signal received by the tag is relatively high as a result of the reader receiving the output identifier signal, moving to an operating mode by using the received reader signal with the relatively high magnitude, to energize the memory tag.
17. A method according to claim 16 wherein the step of moving to an operating mode comprises permitting operation of a memory of the memory tag.
18. A memory tag comprising a resonant circuit part, a detector module and an output generator module, the resonant circuit part being operable to generate a first relatively low magnitude output signal and a second relatively high magnitude output signal respectively in response to a first reader signal and a second reader signal which are respectively issued from a reader at first and second power levels, the magnitude of the first output signal being variable with the magnitude of the first reader signal which is lower in power than the second reader signal, the detector module being responsive to the relatively low magnitude of the first output signal such that the detector module transmits an identifier signal which is configured to induce the reader to issue the second relatively high power level reader signal, and in response to the second output signal, which is induced by the second relatively high power level reader signal, the detector module is operable to cause the tag to move to an operating mode.
19. A memory tag according to claim 18 comprising a memory, wherein the detector module is operable to cause the tag to move to an operating mode by connecting the memory to the resonant circuit part.
20. A memory tag according to claim 18 comprising a rectifying circuit part responsive to the first and second output signals of the resonant circuit part to generate respective output voltages, and wherein the detector module is responsive to the respective magnitudes of the output voltages.
21. A memory tag according to claim 20 wherein the tag comprises a memory and wherein the detector module is operable to energize the tag into the operating mode by connecting the memory to the rectifying circuit part in response to the second output signal, and operable to disconnect the memory from the rectifying circuit part in response to the first output signal.
22. A memory tag according to claim 18 wherein the resonant circuit part comprises a switch, wherein in response to the first output signal, the output generator module is operable to control the switch to transmit the identifier signal, and in response to the second output signal, the memory is operable to control the switch.
23. A memory tag according to claim 18 wherein the output generator module comprises a pseudorandom binary sequence generator to generator an identifier signal comprising a pseudorandum binary sequence.
24. A memory tag according to claim 18 wherein the resonant circuit part is operable to provide inductive coupling to a reader wherein the reader signal is received via the inductive coupling.
25. A method of operating a reader for reading a memory tag comprising:
generating a reader signal normally having a first, relatively low power during a low power search mode,
detecting an identifier signal from a memory tag which is produced by the memory tag in response to receipt of the reader signal having the first relatively low power, and
inducing a high-power read mode by generating, in response to detection of the identifier signal, a reader signal at a second, relatively high power to excite the memory tag into an operating mode wherein data can be transmitted from the memory tag and read by the reader.
26. A method according to claim 25, wherein the step of exciting the memory tag into an operative mode comprises: connecting a memory to a resonant circuit in response to the reader signal being at the second relatively high level.
27. A method according to claim 26 further comprising:
using a rectifying circuit part responsive to the output signal of the resonant circuit to generate an output voltage, and
using the output voltage to control a detector module.
28. A method according to claim 25 wherein the tag comprises a memory and a detector module and wherein the detector module is operable to excite the tag into an operating mode by:
connecting the memory to a rectifying circuit when the output signal is relatively high, and
disconnecting the memory from the rectifying circuit part when the magnitude of the output signal is relatively low.
Description
FIELD OF THE INVENTION
This invention relates to a memory tag powered by a signal generated by a reader, and a reader.
BACKGROUND OF THE INVENTION
Memory tags in the form of Radio Frequency Identification (RFID) tags are well known in the prior art, and the technology is well established (see for example: RFID Handbook, Klaus Finkenzeller, 1999, John Wiley & Sons). RFID tags come in many forms but all comprise an integrated circuit with information stored on it and a coil which enables it to be interrogated by a read/write device generally referred to as a reader. Until recently RFID tags have been quite large, due to the frequency they operate at (13.56 MHz) and the size of coil they thus require, and have had very small storage capacities. Such RFID tags have tended to be used in quite simple applications, such as for file tracking within offices or in place of or in addition to bar codes for product identification and supply chain management.
Much smaller RFID tags have also been developed, operating at various frequencies. For example Hitachi-Maxell have developed “coil-on-chip” technology in which the coil required for the inductive link is on the chip rather than attached to it. This results in a memory tag in the form of a chip of 2.5 mm square, which operates at 13.56 MHz. In addition Hitachi has developed a memory tag referred to as a “mu-chip” which is a chip of 0.4 mm square and operates at 2.45 GHz. These smaller memory tags can be used in a variety of different applications. Some are even available for the tagging of pets by implantation.
Although it is known to provide tags with their own power source, in many applications the tag is also powered by the radio frequency signal generated by the reader. Such a known system is shown in FIG. 1 where a reader is indicated generally at 10 and a tag at 12. The reader 10 comprises a radio frequency generator 13 and a resonant circuit part 11, in the present example comprising an inductor 14 and a capacitor 15 connected in parallel. The inductor 14 comprises a antenna. The resonant circuit part will have a particular resonant frequency in accordance with the capacitance and inductance of the capacitor 15 and the inductor 14, and the frequency generator 13 is operated to generate a signal at that resonant frequency.
The tag 12 similarly comprises a resonant circuit part generally illustrated at 16, a rectifying circuit part generally indicated at 17 and a memory 18. The resonant circuit part 16 comprises an inductor 19 which again comprises in this example a loop antenna, and a capacitor 20. The resonant circuit part 16 will thus have a resonant frequency set by the inductor 19 and capacitor 20. The resonant frequency of the resonant circuit part 16 is selected to be the same as that of the reader 10. The rectifying part comprises a forward-biased diode 21 and a capacitor 22 and thus effectively acts as a half-ware rectifier.
When the reader 10 and the tag 12 are sufficiently close, a signal generated by the frequency generator 13 will cause the resonant circuit part 11 to generate a reader signal comprising a high frequency electromagnetic field. When the resonant circuit part 16 is moved within this field, a current will be caused to flow in the resonant circuit part 16, drawing power from the time varying magnetic field generated by the reader. The rectifying circuit part 17 will then serve to smooth the voltage across the resonant frequency part and provide a power supply storage. The rectifying circuit part 17 is sufficient to supply a sufficiently stable voltage to the memory 18 for the memory to operate.
It is possible however, when no tag 12 is sufficiently close to the reader 10, the electromagnetic field generated by the reader 10 could be coupled to other objects, particularly objects containing metal, such as a glass frame a pen or such wires as may be found on a desk. This may be undesirable. It is possible in such circumstances, the reader would not meet prescribed legal regulations or guidelines relating to the level of radiated power from radio transmitters. However, it will be apparent that simply reducing the power of the signal transmitted by the reader will reduce both the range at which the reader may operate and the power available for operation of the tag 32. An aim of the present invention is to reduce or overcome the above problem.
SUMMARY OF THE INVENTION
According to one aspect of the invention, we provide a memory tag comprising a resonant circuit part, a detector module and an output generator module, the resonant circuit part being operable to generate an output signal in response to a reader signal from a reader, the amplitude of the output signal dependent on the magnitude of the reader signal, the detector module being responsive to the magnitude of the output signal such that, when the magnitude of the output signal is relatively low, the detector module causes the output generator module to transmit an identifier signal, and when the magnitude of the output signal is relatively high, the detector module is operable to cause the tag to move to an operating mode.
The tag may comprise a memory, wherein the detector module may be operable to cause the tag to move to an operating mode by connecting the memory to the resonant circuit part.
The tag may comprise a rectifying circuit part which is responsive to the output signal of the resonant circuit part to generate an output voltage, and the detector module may be responsive to the magnitude of the output voltage.
The detector module may be operable to connect the memory to the rectifying circuit part when the output signal is relatively high and to disconnect the memory from the rectifying circuit part when the magnitude of the output signal is relatively low.
The resonant circuit part may comprise a variable capacitance element, wherein when the magnitude of the output signal is relatively low the output generator module is operable to control the variable capacitance element, and when the magnitude of the output signal is relatively high, the memory is operable to control the variable capacitance element.
The output generator module may comprise a pseudorandom binary sequence generator and wherein the pseudorandom binary sequence generator is operable to control the variable capacitance element to transmit the pseudorandom binary sequence to a reader.
The resonant circuit part may be operable to provide inductive coupling to a reader wherein the reader signal is received via the inductive coupling.
According to a second aspect of the invention, we provide a reader to read a memory tag, the reader comprising a resonant circuit part operable to transmit a reader signal to a memory tag, the reader further being operable to receive a signal from a memory tag, the reader being operable to transmit the signal to the memory tag at a first, relatively low power, and in response to an identifier signal from a memory tag, being operable to transmit a signal to the memory tag at a second, relatively high power.
A resonant circuit part and a signal generator may be operable to supply a drive signal to the resonant circuit part, the reader further comprising an amplitude modulator to control the amplitude of the drive signal supplied from the signal generator to the resonant circuit part.
An identifier signal module may be provided, operable to identify the identifier signal from the memory tag.
The identifier signal module may comprise a correlator operable to identify the identifier signal.
The reader may be operable to provide inductive coupling to the memory tag wherein the reader signal is transmitted via the inductive coupling.
According to a third aspect of the invention, we provide a method of operating a memory tag comprising the steps of detecting a signal received from a reader, and, when the magnitude of the signal is relatively low, transmitting an output identifier signal and when the magnitude of the signal is relatively high, permitting operation of the memory tag.
The step of moving to an operating mode may comprise permitting operation of a memory of the memory tag.
According to a fourth aspect of the invention, we provide a method of operating a reader for reading a memory tag comprising generating a signal having a first, relatively low power, detecting an identifier signal from a memory tag, and in response to detection of the identifier signal, generating a signal at a second, relatively high power.
BRIEF DESCRIPTION OF THE DRAWINGS
The embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings wherein;
FIG. 1 is a diagrammatic illustration of a known reader and memory tag,
FIG. 2 is a diagrammatic illustration of a reader and a memory tag embodying the present invention, and
FIG. 3 is a diagrammatic illustration of a particular reader and memory tag embodying the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 2, a tag embodying the present invention is shown at 30 and a reader shown at 31. The tag 30 comprises a resonant circuit part 32 and a rectifying circuit part 33, together with a memory 34. The resonant circuit part 32 comprises an inductor L2 shown at 35 which comprises an antenna of suitable form and a capacitor L2 shown at 36 connected in parallel in like manner to the tag 12 of FIG. 1. The resonant circuit part 32 further comprises a switch S1 shown at 37 as a field effect transistor (FET) which is switchable between a high resistance, where it acts as an open switch, and a low resistance, where it acts as a closed switch, by applying an appropriate voltage to line 37 a. The rectifying circuit part 33 comprises a diode D1 shown at 40 connected to the resonant circuit part 32 in a forward biased direction and a capacitor C4 shown at 41 connected in parallel with the components of the resonant circuit part 32. The rectifying circuit part 33 operates in like manner to the rectifying circuit part 17 of FIG. 1 as a half-wave rectifier to provide power to the memory 34 when the tag 30 receives a reader signal generated by the reader 31.
The tag 30 further comprises a detector module 42 and an output identifier generator 43. The detector module 42 is connected to the output of the rectifying circuit part 33. The detector module 42 is further operable to control a second switch S2 shown at 44 to connect one of the memory and the identifier signal generator module 43 to the switch S1, and a third switch S3 as shown at 45 connected between the output of the rectifying circuit part 32 and the memory 34. The detector module 42 is responsive to the magnitude of the output voltage of the rectifying circuit part 32 to control the switches S2 S3. When the output voltage has a relatively low magnitude, the detector module 42 is operable to set switch S3 open and connect switch S2 to the identifier signal module 43. When the output voltage has a relatively high magnitude, the detector module 42 is operable to cause the tag 30 to move to an operating mode by closing switch S3, connecting the memory to the rectifying circuit 32, and setting switch S2 to connect the memory 34 to the first switch S1.
The identifier signal generated by the identifier signal generator module 43 may be a pseudorandom binary sequence as discussed below, or may be any appropriate signal to indicate the presence of the tag 30, such as a repeating short sequence of bits, or a serial number corresponding to the tag 30, or indeed any other signal as desired. Different tags 30 or types of tag 30 mat be operable to generate different pseudorandom binary sequences to identify the tag 30 as well as detectably indicate the presence of the tag.
In the present example, the tag 30 is provided on a CMOS chip. The a resonant circuit part 32, excluding the antenna, and the rectifying circuit part 33 occupy an area of approximately 0.5 mm2. The memory 34 in this example is a non-volatile memory providing 1 Mbit of capacity and is of an area of approximately 1 mm2. The memory may for example use FRAM (ferroelectric random access memory) or MRAM (magnetoresistive random access memory). The antenna is provided on the chip and may have only a few turns, for example 5, or in this case one turn. The tag 30 will be of generally square shape in plan view and have an external dimension D for the length of each side of approximately 1 mm
The reader 31 comprises an interrogator module 46 connected to an inductor 47 in the present example an antenna, to provide inductive coupling between the tag 30 and the reader 31. When the switch S1 is closed, it causes an increased current to flow in the resonant circuit part 32, which can be detected by the reader 31 as a drop in voltage across the inductor 47 providing a data output 48. The reader 31 further comprises an identifier signal module 49 connected to the data output 48 operable to identify the identifier signal transmitted by the tag 30 and generate a high power instruction on line 50. The interrogator module 46 is operable to supply a signal to the inductor 47 at a first, relatively low power and, in response to the high power instruction received on line 50, to supply a signal to the inductor at a second relatively high power.
As discussed above, the tag 30 will have a dimension D of about 1 mm, and the reader 31 will be operable to communicate with the tag over a relatively short range, for example approximately 2D, but the distance over which the tag 30 and reader 31 can communicate effectively will vary with the exact details of their construction.
The tag 30 and reader 31 are operable as follows. The reader 31 is initially in “search mode”, that is a tag 30 is not sufficiently close to the antenna 47 for inductive coupling to occur. The interrogator module 46 generates an output reader signal of relatively low power.
When a tag 30 comes sufficiently close to the antenna 47 to provide inductive coupling, for example within about 2D, the reader signal will cause the rectifying circuit part 32 to generate an output voltage having a relatively low magnitude as discussed hereinbefore. The detector module 42 will cause switch S3 to be open and switch S2 connected to the identifier signal generator module 43 as shown in FIG. 2. Sufficient power will be supplied to the tag 30 to operate the identifier signal generator module 43 such that it transmits an appropriate identifier signal. Conveniently, the identifier signal operator module 43 will comprise a pseudorandom binary sequence generator which may simply be assembled out of a shift register and XOR gates in known manner. Such a functionality will require very little power to operate, particularly when provided as part of a CMOS integrated circuit. The module 43 modulates the resonant frequency of the resonant circuit part 32 by operating the switch S1 in accordance with the pseudorandom binary signal. For example, the output of the identifier signal operator module 43 may simply be a series of pulses of relatively high or low voltage encoding the bits of the identifier signal passed to the switch S1. The switch S1 will be open or closed depending on the voltage of the signal, thus transmitting the identifier signal to the reader 31. The interrogator 46 transmits the received data 48 to the identifier signal module 49. On detecting the identifier signal from the tag 30, the identifier signal module 49 will send a high power instruction on a line 50 to the interrogator 46 to switch to high power operation. The interrogator 45 will then send a relatively high power signal to the antenna 47. This will cause the rectifying circuit part 32 to generate a signal comprising an output voltage having a relatively high magnitude which is detected by the detector module 42. The detector module 42 then closes switch S3, connecting the memory 34 to the rectifying circuit part 32, and toggles switch S2 to connect the memory 34 to first switch S1. The tag 30 may then operate to read data from the memory 34 to the reader 31. In particular, a program stored in the memory 34 may be operable to read data held in the memory 34 and control the switch S1 by transmitting a signal having a particular voltage on line 34 a, for example encoding binary digits by pulses of relatively high or low voltage.
Referring now to FIG. 3, a particular embodiment of a memory tag and reader are shown at 30′ and 31′ respectively. The reader 31′ comprises a resonant circuit part 51 which comprises an inductor L1 shown at 52, in this example an antenna and a capacitor C1 shown at 53 connected in parallel. A signal generator 54 is connected to the resonant circuit part 51 to provide a drive signal.
The reader 31′ further comprises a demodulator, generally shown at 55. The demodulator 55 comprises a splitter 56 connected to the frequency generator to split off a part of the drive signal to provide a reference signal. A coupler 57 is provided to split off part of a reflected signal reflected back from the resonant circuit part 51, and pass the reflected signal to a multiplier shown at 58. The multiplier 58 multiplies the reflected signal received from the coupler 57 and the reference signal received from the splitter 56 and passes the output to a low pass filter 59. The low pass filter 59 passes the signal corresponding the phase difference between the reference signal and the reflected signal to an output 60. An amplitude modulator is shown at 61 operable to control the amplitude of the drive signal supplied from the frequency generator 54 to the resonant circuit part 51.
The memory tag 32′ is the same as the memory tag 32 of FIG. 2 except that the switch S1 37 has been replaced with a variable capacitance element generally indicated at 37′ comprising a switch S1′ shown at 38 and a capacitor C3 shown at 39. Operation of the switch S138 will switch the capacitor C3 in and out of the resonant circuit part 32′, thus changing the resonant frequency of the resonant circuit part 32′ causing a relative phase shift in the signal reflected from the resonant circuit part 51. The switch S1′ may comprise an FET and be operable in like manner to the switch 37 as discussed herein before.
In the reader 31′ the reference signal from the splitter 56 will be of the form
S(t)=A cos(ωt)
and the reflected signal R(t) will be of the form
R(t)=a cos(ωt+φ(t))
• where
• A=amplitude of the reference signal,
• a=amplitude of the reflected signal
• φ(t)=the relative phase and
• ω=the frequency of the drive signal generated by the frequency source 45.
R(t) is multiplied by the carrier reference signal S(t) at the multiplier 58, producing a resulting signal a A 2 cos ( 2 ω t + φ ( t ) ) + a A 2 cos ( φ ( t ) )
The first of these terms, the second harmonic, is simply filtered by the low pass filter 59 leaving the second term that comprises the phase difference between the reference and reflected signals. It is a known effect of resonant circuits that when the circuit passes a signal which has a frequency less than the resonant frequency of the circle, a phase lag is introduced to the signal frequency, whilst when the frequency is greater than that of the resonant circuit, a phase lead is induced. Thus, by modulating the frequency of the reflected signal by changing the resonant frequency of the resonant circuit part 32′ of the tag 30′, the reflected signal will have a phase difference relative to the reference signal from the frequency source 54 which may easily be measured by the demodulator as discussed above.
An identifier signal module is shown at 49 connected to the output 60 and operable to control the amplitude modulator 61. In this example, the identifier signal module comprises a correlator. Correlators are particularly useful for identifying weak repetitive signals, and in this example the correlator 48 is operable to identify the pseudorandom binary sequence transmitted by the tag 30. The correlator is operable to control the amplitude modulator 55 to switch the modulator between a relatively low amplitude signal and a relatively high amplitude signal to generate a relatively low or relatively high amplitude output.
The embodiment of FIG. 3 is particularly advantageous in that the data is transmitted from the memory tag 30′ without significantly affecting the output voltage of the rectifying circuit part 33, and the correlator 49 simply receive the identifier signal from the demodulator 55 used to read data from the tag 30′.
The reader 31, 31′ may be provided as a device or a component of a device having any appropriate function or application as desired. For example, a reader might comprise a device whose intended principle function is simply to act as a stand-alone reader. The small size of the reader would permit it to be intergrated into small devices, such as a key fob or pen. The reader may have a display or other understandable output means, or may be suitably adapted to connect another device. It might be envisaged for example that a reader is provided with a suitable memory into which the contents of the memory of a tag are read, and an interface to enable the reader to be connected to another device such as a personal computer to enable the content of the reader memory to be downloaded.
A reader might be provided with a connection to a computer, such that the reader functions as a peripheral of the computer operable to read a tag and supply the read information to the computer for any appropriate application, or indeed write information to the tag. In this example, it might be envisaged that the reader be provided on a computer mouse or a keyboard. It might also be envisaged that a printer be provided with a reader, such that the printer could retrieve a document stored on a tag and print a copy of the document.
A reader may also be provided integrated in or provided as part of a portable device. For example, a personal digital assistant (PDA) might be provided with a reader such that a user may read from and write to a memory tag with the reader and view the retrieved information on a screen of the PDA. Similarly, it might be envisaged that a reader might be built into a mobile telephone, or be connectable thereto to enable information transmitted via the mobile telephone to be read from or written to the memory tag, and made available to a user via the screen of the telephone or as an audible output.
In all of the examples, it will be apparent that the information read from or written to the memory tag may comprise any appropriate type or format as desired, for example text, images, programs, sound files or movie files.
It will of course be apparent that the reader 31 31′ may be provided with any appropriate implementation as desired to switch between a relatively low power search mode and a relatively high power mode where data may be read from or to the tag 30. In a preferred embodiment, the resonant frequency of the resonant circuit part 42, and hence the frequency of the signal generated by the frequency source 45 is about 2.45 GHz, and the resonant frequency of the resonant circuit part 32 is modulated by about 0.05 GHz either side of this reference frequency. At this frequency, component values for the inductors for the capacitors are small, allowing easy integration of the circuit and require relatively small early areas of silicon on an integrated circuit. It is particularly desirable that the circuit for the memory tag 30 30′ be provided as a integrated circuit, for example as a CMOS integrated circuit. Switches S1′, S2, S3 may advantageously be provided as field effect transmitters which are particularly suitable for provision as part of a CMOS integrated circuit.
The tag 30 30′ is particularly advantageous in that it may be used with a CMOS integrated circuit. It is known that the power requirements of a CMOS integrated circuit are proportional to the square of the operating voltage, the capacitance of all the gates found on the circuit and the operation frequency. The pseudorandom binary sequence generator 43 may operate at a relatively low rate, for example on the order of 100 kilobits per second instead of 10 megabits per second for the normal read/write operation of the tag, and may be relatively simply implemented to, for example, provide a repeating sequence of 127 bits at a relatively low power. The correlator 49 is operable to detect the sequence of 127 bits with high confidence, even though the signal generated by the tag may be generated at a relatively low power.
In the present specification “comprises” means “includes or consists of” and “comprising” means “including or consisting of”.
The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.
Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
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Non-Patent Citations
Reference
1"Keyless entry", http://www.all-electronics.de/news4d4b4303e11,print/html, Sep. 1, 2002.
2"Transponder: Arten und Reichweiten", http://web.archive.org/web/20021115010650/Http://www.nur-sicherheit.de/themen/zutrittskontrolle/identi.htm, as of Nov. 15, 2002.
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4English Translation of a German Office Action dated Aug. 27, 2004 issued in corresponding German Application No. 103 53 373.7-53, (6 pp.), Applicant: Hewlett-Packard Co.
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US7183925 *Feb 3, 2003Feb 27, 2007Koninklijke Philips Electronics N.V.Interactive system using tags
US7603082 *Jun 23, 2005Oct 13, 2009Stmicroelectronics S.A.Impedance matching of an electromagnetic transponder reader
US8441099 *Sep 29, 2010May 14, 2013Semiconductor Energy Laboratory Co., Ltd.Wireless chip
US8914665Jul 6, 2006Dec 16, 2014Hewlett-Packard Development Company, L.P.Reading or storing boot data in auxiliary memory of a tape cartridge
US9058550 *Feb 5, 2013Jun 16, 2015Google Technology Holdings LLCMobile devices with RFID capabilities and corresponding memory write methods
US20050140504 *Feb 3, 2003Jun 30, 2005Koninklijke Philips Electronics N.V.Interactive system using tags
US20050225437 *Aug 19, 2004Oct 13, 2005Fujitsu LimitedInformation processing apparatus for receiving predetermined information, and program product and method therefor
US20050285718 *Jun 23, 2005Dec 29, 2005Stmicroelectronics, S.A.Impedance matching of an electromagnetic transponder reader
US20060057762 *Sep 13, 2004Mar 16, 2006Shoei-Lai ChenMethod of building electronic label for electronic device
US20060178816 *Jan 30, 2006Aug 10, 2006Hewlett-Packard Development Company, L.P.Methods, articles and computer program products for providing travel directions
US20070101113 *Jul 6, 2006May 3, 2007Evans Rhys WData back-up and recovery
US20100045441 *Nov 15, 2007Feb 25, 2010Nxp, B.V.Near field communication (nfc) activation
US20110012183 *Sep 29, 2010Jan 20, 2011Semiconductor Energy Laboratory Co., Ltd.Wireless chip
US20140191041 *Feb 5, 2013Jul 10, 2014Motorola Mobility LlcMobile devices with rfid capabilities and corresponding memory write methods
Classifications
U.S. Classification235/492, 340/572.1, 340/10.2
International ClassificationH04B5/00, G06K19/07
Cooperative ClassificationH04B5/0062, G06K19/0723, H04B5/0012, H04B5/0056
European ClassificationH04B5/00C, G06K19/07T, H04B5/00R
Legal Events
DateCodeEventDescription
Oct 31, 2003ASAssignment
Owner name: HEWLETT-PACKARD DEVELOPMENT COMPANY, L.P., TEXAS
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:HEWLETT-PACKARD LIMITED;REEL/FRAME:014658/0537
Effective date: 20031028
Mar 13, 2009FPAYFee payment
Year of fee payment: 4
Feb 26, 2013FPAYFee payment
Year of fee payment: 8
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Digital Engineering: The Transforming Landscape
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Author
• Ali kidwaiContent Architect
The goal is to turn data into information, and information into insights.
18-February-2021
Featured
• Data Engineering
• Cloud Computing
• Data Science
More than 500 years ago, as Leonardo da Vinci experimented with his flying machines, he inked drawings and mocked up physical models before getting down to create his marvels of design. His techniques set the threshold for modern engineering. Going ahead in time, the emergence of computer-aided drafting (CAD) systems in the 20th century automated the drawing process for engineers, and CAD evolved into computer-aided design by adding 3-D modeling and manufacturing planning to software capabilities. Moving ahead, now we have digital twins: dynamic and realistic computer-based instantiations of actual systems and devices.
Digital twins serve as the most accurate replicas of physical objects allowing scientists and engineers to test out the capability and feasibility of their ideas before coming up with critical real-life decisions. The digital twins have moved from trial-and-error-based engineering to systematic, science-based engineering and optimization.
It is made possible by high-performance computing (HPC) advances, now we can utilize digital twins to virtually explore trade spaces, component interaction and performance, operations and manufacturing processes over a system's life cycle or a device in support of performance-based maintenance.
Digital engineering is more than the advanced technology that integrates the data by taking the advantage of a digital skillset. It is the practice in which new applications are delivered and conceived.
Encompassing the utility, methodologies, and process of creating new end-to-end digital products, digital engineering leverages technology and data to produce improvements to applications—or even entirely new solutions.
In the hyper-competitive modern technological world, connectivity and social networking are the norms. Consumers seek value for their investment; thus, they are active participants in the product design process to make sure that the product meets the market demand. Digitizing manufacturing gives automated customization, analytical simulations, and flexible models to deliver personalized manufacturing to consumers.
Fortunately, industries today have new technologies like - big data, cloud computing, mobile, and IoT that help weave in the digital thread to form a directional flow of information. These technologies connect various enterprise sectors for ease of operations, collaboration, quality management, and product traceability. This is particularly crucial in the aerospace industry where components are complex, demand for high quality with zero tolerances must be met, and expense reduction is crucial.
From an engineering perspective, modeling has extremely improved and continues to evolve. The initial 2D modeling techniques have advanced to 3D modeling techniques meshed with analytical simulations to determine the models' workability under numerous conditions. Gradually, 3D models are now printable in what is called 3D printing through pairing computer-aided manufacturing (CAM) and skilled coding.
The result of 3D printing is additive manufacturing techniques that are applicable for both actual production and prototyping. Additive manufacturing processes best align with model-based engineering (MBE) practices and digital 3D models.
For instance, Boeing's 787 Dreamliner whose titanium parts were 3D printed. Additive manufacturing facilitates creating new products and is influential in the design process as complex components can be easily machined, and the number of assembly parts is reduced.
It is clear enough that digital engineering has significantly affected the performance in completing the tasks. A wide array of benefits is offered in cost, safety, quality, and program designs. Following, the role of digital engineering is believed to be able to maximize the penetration to the marketplace so that the products are more acceptable.
This cannot be separated from the increasing reputation as the industry with digital engineering gains its popularity. In line with it, there are numerous benefits as engineers consider the use of digital engineering and here, they are.
1. The use of advanced technology in conducting the projects helps to enhance the confidence toward the project outcomes, enrich the knowledge, reduce the costs and minimize the risk to take.
2. The collaborative environment that involves people from different backgrounds is thought to be the best solution to develop and validate all the ongoing projects. Here, the digitalized systems become the core as the projects are carried out.
3. With the use of digital engineering, it helps the engineers to plan the design with maximum efficiency so that it can maximize the value of the assets.
4. It is undeniable that digital engineering also plays its role to both identify and mitigate the health, risks, and safety of all the construction personnel and the assets.
5. Advanced technology is also significantly important to do rapid tests on determining the solutions virtually and some identifications and validations. This becomes the best solution for the clients as well.
Electric Vehicles
Electric vehicles continue to challenge traditional automotive practices by subsidizing economic and environmental factors. Environmental agencies and industries are pushing for green energy, & digital engineering will be the most viable solution to environmental protection measures and energy.
According to the forecast that by 2030, there will be over 125 million electric cars in the world. This prediction is based on the 54% growth of about 3.1 million electric cars in 2017. With this advancement, digital engineering will continue to play an instrumental role in the automotive industry.
Spacecrafts
SpaceX, a private organization by Elon Musk, has had a breakthrough into outer space to land contracts from governmental agencies venturing into space and NASA. Designing a rocket takes a team of skilled engineers, avionics and structures. The Falcon rocket designed at SpaceX amalgamates product data management (PDM) software and finite element analysis (FEA) coordinated by Siemens' Teamcenter software solution. The complete SpaceX systems have NX software that gives virtual mockups of the Falcon rocket to offer interfaces to designers and engineering components. SpaceX has entirely digitized its operations at its factory through the design stage, manufacturing, and processing. Eventually, digital engineering has propelled SpaceX as the only private company venturing into space.
Virtual Training
Boeing's group of airplane manufacturers has embraced digital engineering. The organization uses an advanced digital toolkit collaborating AR, advanced analytics, cloud computing and IoT to resolve complex issues in the aerospace industry. Augmented reality assists train workers virtually on the production process, therefore reducing real-time training on production floors. Presently, Boeing has a research project on AR with the Digital Manufacturing and Design Innovation Institute (DMDII), a non-profit federal company committed to developing advanced manufacturing technologies and improving American manufacturing competitiveness. By tapping capability sharing, the two organizations utilize 3D cameras with advanced image processing and computer vision algorithms to create a simple, intuitive approach to augmented reality. Therefore, an expert can record instructions while performing a complex operation using innate digital work instructions and unveil it to others for training objectives, thereby increasing training resource availability and reducing expenditures.
Digital Engineering can be viewed as a more collaborative and informed way of working. It is facilitated by digital processes and technological advancements to enable more productive planning methods, operations, designing, & maintaining assets. Through integration and data capture, it seeks to add value to a project at delivery and beyond. Ultimately, the processes entailed in digital engineering are constantly transforming, and the development of disruptive technologies will always persist.
About Author
digital engineering
Ali kidwai
Content Architect
The goal is to turn data into information, and information into insights.
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www.adichemistry.com
ATOMIC STRUCTURE
< Early Atomic models Atomic structure: TOC Hydrogen atomic spectrum >
NATURE OF LIGHT & QUANTUM THEORY
The early theories describing the atomic structure are based on classical physics. However these theories could not explain the behavior of atom completely. The modern view of atomic structure is based on quantum theory introduced by Max Planck.
Before learning the quantum theory, it is necessary to understand the nature of light.
LIGHT
Light is considered as an electromagnetic radiation. It consists of two components i.e., the electric component and the magnetic component which oscillate perpendicular to each other as well as to the direction of path of radiation.
electromagnetic radiation representation
The electromagnetic radiations are produced by the vibrations of a charged particle. The properties of light can be explained by considering it as either wave or particle as follows (dual nature).
WAVE NATURE OF LIGHT
According to the wave theory proposed by Christiaan Huygens, light is considered to be emitted as a series of waves in all directions. The following properties can be defined for light by considering the wave nature.
Wavelength (λ): The distance between two successive similar points on a wave is called as wavelength. It is denoted by λ.
Units: cm, Angstroms (Ao), nano meters (nm), milli microns (mµ) etc.,
Note:
1 Ao = 10-8 cm.
1 nm= 10-9m = 10-7cm
Frequency (ν): The number of vibrations done by a particle in unit time is called frequency. It is denoted by 'ν'.
Units: cycles per second = Hertz = sec-1
Velocity (c): Velocity is defined as the distance covered by the wave in unit time. It is denoted by 'c'.
Velocity of light = c = 3.0 x 108 m.sec-1 = 3.0 x 1010 cm.sec-1
Note: For all types of electromagnetic radiations, the velocity is a constant value. The relation between velocity (c), wavelength (λ) and frequency (ν) can be given by following equation.
velocity = frequency x wavelength
c = νλ
Wave number (): The number of waves spread in a length of one centimeter is called wave number. It is denoted by . It is the reciprocal of wavelength, λ.
units: cm-1, m-1
Amplitude: The distance from the midline to the peak or the trough is called amplitude of the wave. It is usually denoted by 'A' (a variable). Amplitude is a measure of the intensity or brightness of light radiation.
PARTICLE NATURE OF LIGHT
Though most of the properties of light can be understood by considering it as a wave, some of the properties of light can only be explained by using particle (corpuscular) nature of it. Newton considered light to possess particle nature. In the year 1900, in order to explain black body radiations, Max Planck proposed Quantum theory by considering light to possess particle nature.
PLANCK'S QUANTUM THEORY
Black body: The object which absorbs and emits the radiation of energy completely is called a black body. Practically it is not possible to construct a perfect black body. But a hollow metallic sphere coated inside with platinum black with a small aperture in its wall can act as a near black body. When the black body is heated to high temperatures, it emits radiations of different wavelengths.
The following curves are obtained when the intensity of radiations are plotted against the wavelengths, at different temperatures.
Following are the conclusions that can be drawn from above graphs.
1) At a given temperature, the intensity of radiation increases with wavelength and reaches a maximum value and then starts decreasing.
2) With increase in temperature, the wavelength of maximum intensity (λmax) shifts towards lower wavelengths. According to classical physics, energy should be emitted continuously and the intensity should increase with increase in temperature. The curves should be as shown by dotted line.
In order to explain above experimental observations Max Planck proposed the following theory.
Quantum theory:
1) Energy is emitted due to vibrations of charged particles in the black body.
2) The radiation of energy is emitted or absorbed discontinuously in the form of small discrete energy packets called quanta
3) Each quantum is associated with definite amount of energy which is given by the equation E=hν.
Where
h = planck's constant = 6.625 x 10-34 J sec = 6.625 x10-27 erg sec
ν= frequency of radiation
4) The total energy of radiation is quantized i.e., the total energy is an integral multiple of hν. It can only have the values of 1 hν or 2 hν or 3 hν. It cannot be the fractional multiple of hν.
5) Energy is emitted and absorbed in the form of quanta but propagated in the form of waves.
EINSTEIN'S GENERALIZATION OF QUANTUM THEORY
Einstein generalized the quantum theory by applying it to all types of electromagnetic radiations. He explained photoelectric effect using this theory.
Photoelectric Effect: The ejection of electrons from the surface of a metal, when the metal is exposed to light of certain minimum frequency, is called photoelectric effect
The frequency of light should be equal or greater than a certain minimum value characteristic of the metal. This is called threshold frequency, νo
The photoelectric effect cannot be explained by considering the light as wave. Einstein explained photoelectric effect by applying quantum theory as follows:
1. All electromagnetic radiations consists of small discrete energy packets called photons. These photons are associated with definite amount of energy given by the equation E=hν.
2. Energy is emitted, absorbed as well as propagated in the form of photons only.
3. The electron is ejected from the metal, only when a photon of sufficient energy strikes the electron. When a photon strikes the electron, some part of the energy of photon is used to free the electron from the attractive forces in the metal atom and the remaining part is converted into kinetic energy.
hν = W + K.E
Where
W = energy required to overcome the attractions
K.E = kinetic energy of the electron
Since the frequency corresponding to the minimum energy required to overcome the attraction is called threshold frequency, νo, the above equation can be written as:
hν = hνo + K.E
or
K.E = hνo- hν = h(νo- ν)
< Early Atomic models Atomic structure: TOC Hydrogen atomic spectrum >
Author: Aditya vardhan Vutturi
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Satellites Orbiting Earth
How a Satellite Works
Satellites are very complex machines that require precise mathematical calculations in order for them to function. The satellite has tracking systems and very sophisticated computer systems on board. Accuracy in orbit and speed are required for the satellite to keep from crashing back down to Earth. There are several different types of orbits that the satellite can take. Some orbits are stationary and some are elliptical.”Satellite Orbit”
Low Earth Orbit
A satellite is in “Low Earth Orbit” when it circles in an elliptical orbit close to Earth. Satellites in low orbit are just hundreds of miles away. These satellites travel at high speeds preventing gravity from pulling them back to Earth. Low Orbit Satellites travel approximately 17,000 miles per hour and circle the Earth in an hour and a half.
Polar Orbit
This is how a satellite travels in a polar orbit.
This is how a satellite travels in a polar orbit. These orbits eventually pass the entire surface of the Earth.
Polar Orbiting Satellites circle the planet in a north-south direction as Earth spins beneath it in an east-west direction. Polar Orbits enable satellites to scan the entire surface of the Earth. Like pealing an orange peal in a circular motion from top to bottom. Remote sensing satellites, weather satellites, and government satellites are almost always in polar orbit because of the coverage. Polar orbits cover the Earth’s surface thoroughly. The polar obit occupied by a satellite has a constant location in which it passes over. ALL POLAR ORBITING SATELLITES INTERSECT The North Pole at their same point. While one Polar orbit satellite is over America, another Polar Satellite is passing over the North Pole. So the North Pole has a constant flow of UHF and higher microwaves hitting it. The illustration shows that the common passing point for Polar Orbiting Satellites is over the North Pole.
A polar orbiting satellite will pass over the Earths equator at a different longitude on each of its orbits; however, Polar Orbiting satellites pass over the North Pole every time. Polar orbits are often used for earth mapping, earth observation, weather satellites, and reconnaissance satellites. This orbit has a disadvantage. No one spot of the Earth’s surface can be sensed continuously from a satellite in a polar orbit.
This is from U.S. Army Information Systems Engineering Command.
“In order to fulfill the military need for protected communication service, especially low probability of intercept/detection (LPI/LPD), to units operating north of 65 degree northern latitude, the space communications architecture includes the polar satellite system capability. An acceptable approach to achieving this goal is to fly a low capacity EHF system in a highly elliptical orbit, either as a hosted payload or as a “free-flyer,” to provide service during a transition period, nominally 1997-2010. A single, hosted EHF payload is already planned. Providing this service 24 hours-a-day requires a two satellite constellation at high earth orbit (HEO). Beyond 2010, the LPI/LPD polar service could continue to be provided by a high elliptical orbit HEO EHF payload, or by the future UHF systems.” (quote from www.fas.org)
THERE IS A CONSTANT 24 HOUR EHF AND HIGHER MICROWAVE TRANSMISSION PASSING OVER THE NORTH POLE!
“Geo Synchronous” Orbit
This is how a satellite travels in a Equitorial orbit
This is how a satellite travels in a “Geo Synchronous” orbit. Equatorial orbits are also called “Geostationary”. These satellites follow the rotation of the Earth.
A satellite in a “Geo Synchronous” orbit hovers over one spot and follows the Earths spin along the equator. Go to this link for more information on “Geo synchronous Orbits”. Earth takes 24 hours to spin on its axis. In the illustration you can see that an “Geo Synchronous” Orbit follows the equator and never covers the North or South Poles. The footprints of “Geo Synchronous” orbiting satellites do not cover the polar regions, so communication satellites in “Geo Synchronous” orbits in cannot be accessed in the northern and southern polar regions.
Because the “Geo Synchronous” satellite does not move from the area that it covers, these satellites are used for telecommunications, gps trackers, television broadcasting, government, and internet. Because they are stationary, their orbits are much farther from the Earth than the Polar orbiting satellites. If a stationary satellite is too close to the Earth, it will crash back down at a faster rate. They say there are about 300 “Geo Synchronous” satellites in orbit right now. Of course, these are the satellites that the public is allowed to know about, that are not governmentally classified.
Satellite Anatomy
This is the Atatomy of a Satellite.
This is the Anatomy of a Satellite.
A satellite is made up of several instruments that work together to operate the satellite during its mission. This illustration to the left demonstrates the parts of a satellite.
The command and data system controls all of the satellite functions. This is a very complex computer system that communicates all of the satellite flight operations, where the satellite points, and any other mathematical operations.
The Pointing control directs the satellite in order for the satellite to keep a steady flight path. This system is a complex sensor instrument that keeps the satellite pointing in the same direction. The satellite uses a propulsion system called “momentum wheels” that adjusts the position of the satellite into its proper place. Scientific observation satellites have more precise propulsion systems than do communications satellites.
The Communications system has a transmitter, a receiver, and various antennas to transmit data to the Earth . On Earth, Ground control sends instructions and data to the satellite’s computer through the Antenna. Pictures, data, television, radio, and many other data is sent by the satellite back to practically everyone on Earth.
The Power system needed power and operate the satellite is an efficient solar panel array that obtains energy from the Sun’s rays. Solar arrays make electricity from the sunlight and store the electricity in rechargeable batteries.
The Payload is what a satellite needs to perform its job. A weather satellite would have a payload that consist of an Image sensor, digital camera, telescope, and other thermal and weather sensing devices.
The Thermal Control is the protection required to prevent damage to the satellite’s instrumentation and components in. Satellite are exposed to extreme temperature changes. Temperatures range from 120 degrees below zero to 180 degrees above zero. Heat distribution units and thermal blankets to protect the electronics and components from temperature damage.
Satellite Footprints
A single satellite footprint
Here you can see one footprint covers an enormous area.
Geostationary satellites have a very broad view of Earth. The footprint of one Echo Starbroadcast satellite covers almost all of North America. They stay over the Earth at same the same location so we always know where they are. Direct contact with the satellite can be made because Equatorial Satellites are fixed.
Many communications satellites travel in Equatorial orbits, including those that relay TV signals into our homes; However, the size of the footprint of one satellite covers the entire Northern America.
The multi path effect that occurs when satellite transmissions are obstructed by topographical entities also provides insight on microwave global warming. Microwaves are being bombarded upon our planet. Our planet absorbs and obstructs the waves from space. Microwaves penetrate through all of our atmosphere and bounce and echo off of the Earth. Imagine the footprint overlaps that are being produced by the thousands of satellites in orbit right now?
coverage 8 pic
Here you can see the footprint overlapping the that satellites make. Each satellite covers an enormous area.
The closer the satellite is to something the more power will be exerted on the object. The farther the waves have to go the less power they will have. Because the atmosphere is so much closer to the satellite, there is a stronger beam of energy going through the clouds and atmosphere. This stronger power causes a higher rate of warming in the atmosphere than it does on the surface of the Earth.
The illustration to the right shows how eight satellites microwave an enormous part of our Earth. When the radio signals reflect off of surrounding terrain; buildings, canyon walls, hard ground multi path issues occur due to multiple waves doubling over themselves. These delayed signals can cause poor signals. Ultimately, the water, ice, and Earth are absorbing and reflecting microwaves in many different directions. Microwaves passing through Earths atmospheres are causing radio frequency heating at the molecular level.
System spectral efficiency
“In wireless networks, the system spectral efficiency is a measure of the quantity of users or services that can be simultaneously supported by a limited radio frequency bandwidth in a defined geographic area.” The capacity of a wireless network can be measured by calculating the maximum simultaneous phone calls over 1 MHz frequency spectrum. This is measured in Erlangs//MHz/cell, Erlangs/MHz/sector, Erlangs/MHz/site, or Erlangs/MHz/km measurements. Modern day cell phones take advantage of this type of transmission. These cell phones transmit a microwave transmission that is twice the frequency of a microwave oven in your home.
This is a misconception of how microwave frequencies travel.
This is a misconception of how microwave frequencies travel.
An example of a spectral efficiency can be found in the satellite RADARSAT-1. In 1995 RADARSAT-1, an Earth observation satellite from Canada, was launched in an orbit above the Earth. RADRASAT-1 provides images of the Earth, scientific and commercial, used in agriculture, geology, hydrology, arctic surveillance, oceanography, cartography, ice and ocean monitoring, forestry, detecting ocean oil slicks, and many other applications. This satellite uses continuous high microwave transmissions. A Synthetic Aperture Radar (SAR) system is a type of sensor that images the Earth at a single microwave frequency of 5.3 GHz. SAR systems transmit microwaves towards the surface of the Earthy and record the reflections from the surface. This satellite can image the Earth during any time and in any atmospheric condition.
This is how microwave frequencies travel
This is how microwave frequencies actually travel.
A Common misconception about microwave transmissions is that the transmission is directly beaming straight into the receiving antennae. (See misconception illustration) This however, is not true. Transmissions are spread into the air in a spherical direction. The waves travel in every direction until they find a receiver or some dielectric material to pass into.
When a microwave transmission is sent to a receiving satellite dish the transmission is sent in a spherical direction. (See how microwaves travel illustration) The signal passes through all parts of that sphere until it finds a connection. All microwaves, not received by an antennae, pass through the dielectric material in the earth. Dielectric material is primarily water and ice.
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The Celestial Sphere
Humans perceive in Euclidean space -> straight lines and planes. But, when distances are not visible (i.e. very large) than the apparent shape that the mind draws is a sphere -> thus, we use a spherical coordinate system for mapping the sky with the additional advantage that we can project Earth reference points (i.e. North Pole, South Pole, equator) onto the sky. Note: the sky is not really a sphere!
From the Earth’s surface we envision a hemisphere and mark the compass points on the horizon. The circle that passes through the south point, north point and the point directly over head (zenith) is called the meridian.
This system allows one to indicate any position in the sky by two reference points, the time from the meridian and the angle from the horizon. Of course, since the Earth rotates, your coordinates will change after a few minutes.
The horizontal coordinate system (commonly referred to as the alt-az system) is the simplest coordinate system as it is based on the observer’s horizon. The celestial hemisphere viewed by an observer on the Earth is shown in the figure below. The great circle through the zenith Z and the north celestial pole P cuts the horizon NESYW at the north point (N) and the south point (S). The great circle WZE at right angles to the great circle NPZS cuts the horizon at the west point (W) and the east point (E). The arcs ZN, ZW, ZY, etc, are known as verticals.
The two numbers which specify the position of a star, X, in this system are the azimuth, A, and the altitude, a. The altitude of X is the angle measured along the vertical circle through X from the horizon at Y to X. It is measured in degrees. An often-used alternative to altitude is the zenith distance, z, of X, indicated by ZX. Clearly, z = 90 – a. Azimuth may be defined in a number of ways. For the purposes of this course, azimuth will be defined as the angle between the vertical through the north point and the vertical through the star at X, measured eastwards from the north point along the horizon from 0 to 360°. This definition applies to observers in both the northern and the southern hemispheres.
It is often useful to know how high a star is above the horizon and in what direction it can be found – this is the main advantage of the alt-az system. The main disadvantage of the alt-az system is that it is a local coordinate system – i.e. two observers at different points on the Earth’s surface will measure different altitudes and azimuths for the same star at the same time. In addition, an observer will find that the star’s alt-az coordinates changes with time as the celestial sphere appears to rotate.
Celestial Sphere:
To determine the positions of stars and planets on the sky in an absolute sense, we project the Earth’s spherical surface onto the sky, called the celestial sphere.
The celestial sphere has a north and south celestial pole as well as a celestial equator which are projected reference points to the same positions on the Earth surface. Right Ascension and Declination serve as an absolute coordinate system fixed on the sky, rather than a relative system like the zenith/horizon system. Right Ascension is the equivalent of longitude, only measured in hours, minutes and seconds (since the Earth rotates in the same units). Declination is the equivalent of latitude measured in degrees from the celestial equator (0 to 90). Any point of the celestial (i.e. the position of a star or planet) can be referenced with a unique Right Ascension and Declination.
The celestial sphere has a north and south celestial pole as well as a celestial equator which are projected from reference points from the Earth surface. Since the Earth turns on its axis once every 24 hours, the stars trace arcs through the sky parallel to the celestial equator. The appearance of this motion will vary depending on where you are located on the Earth’s surface.
Note that the daily rotation of the Earth causes each star and planet to make a daily circular path around the north celestial pole referred to as the diurnal motion.
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