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https://what-is-this.net/en/define/hygrometer | 2018-04-23T11:13:02 | s3://commoncrawl/crawl-data/CC-MAIN-2018-17/segments/1524125945942.19/warc/CC-MAIN-20180423110009-20180423130009-00476.warc.gz | 0.921881 | 2,659 | CC-MAIN-2018-17 | webtext-fineweb__CC-MAIN-2018-17__0__92402103 | en | A hygrometer is an instrument used for measuring the water vapor in the atmosphere, in soil, or in confined spaces. Humidity measurement instruments usually rely on measurements of some other quantity such as temperature, pressure, mass or a mechanical or electrical change in a substance as moisture is absorbed. By calibration and calculation, these measured quantities can lead to a measurement of humidity. Modern electronic devices use temperature of condensation (the dew point), or changes in electrical capacitance or resistance to measure humidity differences. The first crude hygrometer was invented by the Italian Renaissance polymath Leonardo da Vinci in 1480 and a more modern version was created by Swiss polymath Johann Heinrich Lambert in 1755.
The maximum amount of water vapor that can be held in a given volume of air (saturation) varies greatly by temperature; cold air can hold less mass of water per unit volume than hot air. Most instruments respond to (or are calibrated to read) relative humidity (RH), which is the amount of water relative to the maximum at a particular temperature expressed as per cent.
==Classical hygrometers== ===Ancient hygrometers=== Prototype hygrometers were devised and developed during the Western Han dynasty in Ancient China to study weather. . The Chinese used a bar of charcoal and a lump of earth: its dry weight was taken and then compared with its damp weight after being exposed in the air. The differences in weight were used to tally the humidity level. Other techniques were applied using mass to measure humidity, such as when the air was dry, the bar of charcoal would be light, while when the air was humid, the bar of charcoal would be heavy. By hanging a lump of earth and a bar of charcoal on the two ends of a staff separately and adding a fixed lifting string on the middle point to make the staff horizontal in dry air, an ancient hygrometer was made.
=== Psychrometer (Wet-and-dry-bulb thermometer)===
A psychrometer, or wet-and-dry-bulb thermometer, consists of two thermometers, one that is dry and one that is kept moist with distilled water on a sock or wick. At temperatures above the freezing point of water, evaporation of water from the wick lowers the temperature, so that the wet-bulb thermometer usually shows a lower temperature than that of the dry-bulb thermometer. When the air temperature is below freezing, however, the wet-bulb is covered with a thin coating of ice and may be warmer than the dry bulb.
Relative humidity is computed from the ambient temperature as shown by the dry-bulb thermometer and the difference in temperatures as shown by the wet-bulb and dry-bulb thermometers. Relative humidity can also be determined by locating the intersection of the wet and dry-bulb temperatures on a psychrometric chart. The two thermometers coincide when the air is fully saturated, and the greater the difference the drier the air. Psychrometers are commonly used in meteorology, and in the HVAC industry for proper refrigerant charging of residential and commercial air conditioning systems.
A sling psychrometer, which uses thermometers attached to a handle or length of rope and spun in the air for about one minute, is sometimes used for field measurements, but is being replaced by more convenient electronic sensors. A whirling psychrometer uses the same principle, but the two thermometers are fitted into a device that resembles a ratchet or football rattle.
===Chilled mirror dew point hygrometer=== Dew point is the temperature at which a sample of moist air (or any other water vapor) at constant pressure reaches water vapor saturation. At this saturation temperature, further cooling results in condensation of water. Chilled mirror dewpoint hygrometers are some of the most precise instruments commonly available. They use a chilled mirror and optoelectronic mechanism to detect condensation on the mirror's surface. The temperature of the mirror is controlled by electronic feedback to maintain a dynamic equilibrium between evaporation and condensation, thus closely measuring the dew point temperature. An accuracy of 0.2 °C is attainable with these devices, which correlates at typical office environments to a relative humidity accuracy of about ±1.2%. These devices need frequent cleaning, a skilled operator and periodic calibration to attain these levels of accuracy. Even so, they are prone to heavy drifting in environments where smoke or otherwise impure air may be present.
More recently, spectroscopic chilled-mirrors have been introduced. In this techniques, the dewpoint is detected using a spectroscopic detection, ascertaining the nature of the condensation. This method avoids many of the pitfalls of the previous chilled-mirrors and has been shown to be able to operate drift free.
===Capacitive=== For applications where cost, space, or fragility are relevant, other types of electronic sensors are used, at the price of a lower accuracy. In capacitive hygrometers, the effect of humidity on the dielectric constant of a polymer or metal oxide material is measured. With calibration, these sensors have an accuracy of ±2% RH in the range 5–95% RH. Without calibration, the accuracy is 2 to 3 times worse. Capacitive sensors are robust against effects such as condensation and temporary high temperatures. Capacitive sensors are subject to contamination, drift and aging effects, but are suitable for many applications.
===Resistive=== In resistive hygrometers, the change in electrical resistance of a material due to humidity is measured. National standards based on this type of measurement have been developed in US, UK, EU and Japan. The inconvenience of using this device means that it is usually only used to calibrate less accurate instruments, called Transfer Standards.
==Applications== Aside from greenhouses and industrial spaces, hygrometers are also used in some incubators, saunas, humidors and museums. They are also used in the care of wooden musical instruments such as pianos, guitars, violins, and harps which can be damaged by improper humidity conditions. In residential settings, hygrometers are used to assist in humidity control (too low humidity can damage human skin and body, while too high humidity favors growth of mildew and dust mite). Hygrometers are also used in the coating industry because the application of paint and other coatings may be very sensitive to humidity and dew point. With a growing demand on the amount of measurements taken the psychrometer is now replaced by a dewpoint gauge known as a dewcheck. These devices make measurements a lot faster but are often not allowed in explosive environments.
==Difficulty of accurate humidity measurement== Humidity measurement is among the more difficult problems in basic meteorology. According to the WMO Guide, "The achievable accuracies [for humidity determination] listed in the table refer to good quality instruments that are well operated and maintained. In practice, these are not easy to achieve." Two thermometers can be compared by immersing them both in an insulated vessel of water (or alcohol, for temperatures below the freezing point of water) and stirring vigorously to minimize temperature variations. A high-quality liquid-in-glass thermometer if handled with care should remain stable for some years. Hygrometers must be calibrated in air, which is a much less effective heat transfer medium than is water, and many types are subject to drift so need regular recalibration. A further difficulty is that most hygrometers sense relative humidity rather than the absolute amount of water present, but relative humidity is a function of both temperature and absolute moisture content, so small temperature variations within the air in a test chamber will translate into relative humidity variations.
In a cold and humid environment, sublimation of ice may occur on the sensor head, whether it is a hair, dew cell, mirror, capacitance sensing element, or dry-bulb thermometer of an aspiration psychrometer. The ice on the probe matches the reading to the saturation humidity with respect to ice at that temperature, i.e. the frost point. However, a conventional hygrometer is unable to measure properly above the frost point, and the only way to go around this fundamental problem is to use a heated humidity probe.
Accurate calibration of the thermometers used is fundamental to precise humidity determination by the wet-dry method. The thermometers must be protected from radiant heat and must have a sufficiently high flow of air over the wet bulb for the most accurate results. One of the most precise types of wet-dry bulb psychrometer was invented in the late 19th century by Adolph Richard Aßmann (1845–1918); in English-language references the device is usually spelled "Assmann psychrometer." In this device, each thermometer is suspended within a vertical tube of polished metal, and that tube is in turn suspended within a second metal tube of slightly larger diameter; these double tubes serve to isolate the thermometers from radiant heating. Air is drawn through the tubes with a fan that is driven by a clockwork mechanism to ensure a consistent speed (some modern versions use an electric fan with electronic speed control). According to Middleton, 1966, "an essential point is that air is drawn between the concentric tubes, as well as through the inner one."
It is very challenging, particularly at low relative humidity, to obtain the maximal theoretical depression of the wet-bulb temperature; an Australian study in the late 1990s found that liquid-in-glass wet-bulb thermometers were warmer than theory predicted even when considerable precautions were taken; these could lead to RH value readings that are 2 to 5 percent points too high.
One solution sometimes used for accurate humidity measurement when the air temperature is below freezing is to use a thermostatically-controlled electric heater to raise the temperature of outside air to above freezing. In this arrangement, a fan draws outside air past (1) a thermometer to measure the ambient dry-bulb temperature, (2) the heating element, (3) a second thermometer to measure the dry-bulb temperature of the heated air, then finally (4) a wet-bulb thermometer. According to the World Meteorological Organization Guide, "The principle of the heated psychrometer is that the water vapour content of an air mass does not change if it is heated. This property may be exploited to the advantage of the psychrometer by avoiding the need to maintain an ice bulb under freezing conditions.".
Since the humidity of the ambient air is calculated indirectly from three temperature measurements, in such a device accurate thermometer calibration is even more important than for a two-bulb configuration.
===Saturated salt calibration=== Various researchers have investigated the use of saturated salt solutions for calibrating hygrometers. Slushy mixtures of certain pure salts and distilled water have the property that they maintain an approximately constant humidity in a closed container. A saturated table salt (Sodium Chloride) bath will eventually give a reading of approximately 75%. Other salts have other equilibrium humidity levels: Lithium Chloride ~11%; Magnesium Chloride ~33%; Potassium Carbonate ~43%; Potassium Sulfate ~97%. Salt solutions will vary somewhat in humidity with temperature and they can take relatively long times to come to equilibrium, but their ease of use compensates somewhat for these disadvantages in low precision applications, such as checking mechanical and electronic hygrometers.
==See also== * Automated airport weather station * Dewcell * Humidistat * Moisture analysis
* [https://web.archive.org/web/20090313042255/http://www.ima.co.uk/theory.html IMA moisture measurement training site] * [https://www.usatoday.com/weather/wsling.htm USATODAY.com: How a Sling Psychrometer Works] * [https://web.archive.org/web/20071021203311/http://ts.nist.gov/MeasurementServices/Calibrations/Humidity.cfm NIST page on humidity calibration] * [http://www.veriteq.com/humidity/calibration.htm Article on difficulty of humidity calibration] * [http://www.padfield.org/tim/cfys/datalog/datlog4.php Article on RH sensors] * [http://www.esrl.noaa.gov/gmd/ozwv/wvap/ NOAA homepage for cryogenic chilled-mirror frostpoint hygrometers]
Category:Atmospheric thermodynamics Category:Chinese inventions Category:Italian inventions Category:Meteorological instrumentation and equipment Category:Navigational equipment Category:Psychrometrics Category:Swiss inventions | physics |
https://www.aciers-coste.com/en/knowledge/hardening/ | 2020-12-02T04:07:35 | s3://commoncrawl/crawl-data/CC-MAIN-2020-50/segments/1606141686635.62/warc/CC-MAIN-20201202021743-20201202051743-00237.warc.gz | 0.918487 | 253 | CC-MAIN-2020-50 | webtext-fineweb__CC-MAIN-2020-50__0__3643414 | en | Thickness: from 0.2 to 3 mm
Width: from 6.5 to 315 mm
Hardening is a metallurgical operation that is part of the heat treatments. It consists of heating a material to a temperature known as phase change temperature or solution temperature of chemical compounds, depending on the purpose of the quenching, for the time required to transform the entire heated mass and then cooling the entire mass at a rate sufficient to trap chemical elements that may have diffused into the crystalline solid at high temperature during the reverse transformation. The chemical elements trapped in the low temperature phase then create tensions in the crystalline meshes which contribute to the increase of certain mechanical characteristics of the hardened part.
The plastic deformation mechanism (with deformation when returning to the resting state) of a metal corresponds to the displacement of crystalline irregularities (lacunar defects called “dislocations”). The stresses introduced into the metal through hardening make it difficult to move these dislocations (by increasing the level of energy required to move them from one mesh to another) and thus bring the elastic strength of the metal closer to its breaking strength.
Our hardening line allows us to offer you specific hardness levels adapted to your needs. | physics |
https://ionos.kz/en/lab-spase-weather-2/ | 2023-11-29T05:20:56 | s3://commoncrawl/crawl-data/CC-MAIN-2023-50/segments/1700679100056.38/warc/CC-MAIN-20231129041834-20231129071834-00221.warc.gz | 0.673557 | 4,995 | CC-MAIN-2023-50 | webtext-fineweb__CC-MAIN-2023-50__0__97279161 | en | Head of the Laboratory: Olga Kryakunova, candidate of physical and mathematical sciences
Directions of research:
- monitoring of the neutron component of cosmic rays on the high-mountain neutron monitor 18NM-64 (height 3340 m above sea level, “Cosmostation”);
- physics of galactic and solar cosmic rays, features of their propagation from the boundaries of the heliosphere to the Earth using the 18NM-64 high-altitude neutron monitor and neutron monitors of the world network;
- physics of near-Earth space, in particular, the behavior of the density and anisotropy of galactic cosmic rays, the geomagnetic field, high-energy magnetospheric electrons in geostationary orbit and high-energy protons;
- daily diagnostics of near-Earth space using the Kazakhstani multi-level system for diagnosing and forecasting space weather, including real-time measurements of the intensity of the neutron component of cosmic rays on the 18NM-64 neutron monitor, the geomagnetic field strength and solar radio emission at frequencies of 1 GHz and 2.8 GHz, and also available in the world measurements of solar activity in different wavelength ranges, interplanetary and near-Earth environment based on observations on space observatories and satellites;
- identification of disturbed periods of space weather and their solar sources;
- development of methods for forecasting the radiation and geomagnetic situation based on the data of a network of neutron monitors, ground-based and satellite measurements;
- daily forecast of the average daily Ap-index of geomagnetic activity and the flux of solar radio emission (frequency 2800 MHz) for 55 days in numerical and graphical form, Forecast of the probability of proton increases with a maximum flux >10 pfu for particles with energies >10 MeV and >100 MeV) by 28 days in numerical and graphical form, the forecast of the fluence of high-energy magnetospheric electrons (E> 2 MeV) in geostationary orbits for 28 days;
- study of the influence of space weather factors on the functioning of satellites and aviation;
- study of lithospheric-atmospheric-ionospheric connections and mechanisms of transmission of disturbances from the lithosphere to ionospheric heights at the stage of preparation and occurrence of large earthquakes based on ground-based and satellite recording tools, as well as the development of a theoretical model of electromagnetic lithospheric-atmospheric-ionospheric connections based on the equations of electrodynamics in an anisotropic medium (supervisor of the works, Ph.D. Salikhov N.M.).
- US Air Force grant (special contract (SPC-98-4035) with Air Force Research Laboratory EOARD/AFMC F617089-98-WE064) “Monitoring and Investigation of Ground Level Solar Cosmic Ray Enhancements by Means of High Altitude Neutron Monitor” and the study of ground-based increases in solar cosmic rays using a high-mountain neutron monitor”);
- European grant INTAS-00-0810 “Improvement of methods of control and prognosis of periods of dangerous influence of space weather on satellite’s electronics”;
- European grant INTAS-2000-752 “Key parameters for space weather”;
- European Union Grant under FP7 “Real-time database for high resolution Neutron Monitor measurements (NMDB)” (grant agreement No. 213007, “Establishment of a high-resolution real-time neutron monitor measurement database”).
- Grant project IRN АР088559161 “High-energy magnetospheric electrons and the state of the interplanetary medium”.
The laboratory scientific team participates in the implementation of the following international programs: the international project VarSITI (Variability of the Sun and its impact on the Earth), whose tasks are to study the impact of solar factors on the Earth and near-Earth space and the program of the UN Committee for the Peaceful Exploration of Space UNCOPUOS “International initiatives in the field of space exploration weather.” International cooperation in the field of cosmic ray and space weather research is carried out within the framework of the European collaboration NMDB (www.nmdb.eu) with scientists from far-flung countries (Germany, France, USA, Finland, Switzerland, Slovakia, Greece, Italy, Israel, Spain) and neighboring countries (Russia, Armenia), which is reflected in joint publications
The laboratory staff maintains and upgrades the neutron monitor 18NM-64 and other experimental high-mountain facilities.
The experimental base of the laboratory is located at the high-mountain stations of the institute: the high-mountain base “Cosmostation” (3340 m above sea level) and the high-mountain radio range “Orbit” (2700 m above sea level), as well as at the institute and includes the following facilities:
- neutron supermonitor 18NM-64 (3340 m above sea level, geomagnetic cutoff rigidity R=6.7 GV). It has been operating continuously since 1973. The institute’s cosmic ray station (international designation AATV) with a neutron monitor is one of the key stations in the world network. Experimental data are presented in real time on the website of the Institute. The station is part of the international network of cosmic ray stations NMDB (www.nmdb.eu), where cosmic ray intensity and atmospheric pressure data are sent every minute. Neutron monitor measurements, software, data processing techniques and hardware are constantly upgraded and meet international standards;
- atmospheric pressure sensor BRS-1 (3340 m above sea level);
- equipment for recording solar radio emission at frequencies of 1 GHz and 2.8 GHz, Callisto solar radio emission spectrograph (part of the e-Callisto international network). The Callisto solar radio emission spectrograph allows recording solar radio bursts of II, III, IV, V types and predicting the geoeffectiveness of flare activity (Radio polygon “Orbita”, 2750 m above sea level);
- A.V. Gurevich, G.K. Garipov, A.M. Almenova, V.P. Antonova, A.P. Chubenko, O.A. Kalikulov, A.N. Karashtin, O.N. Kryakunova, V.Yu. Lutsenko, G.G. Mitko, K.M. Mukashev, R.A. Nam, N.F. Nikolaevsky, V.I. Osedlo, M.I. Panasyuk, M.O. Ptitsyn, V.V. Piscal, V.A. Ryabov, N.O. Saduev, T.Kh. Sadykov, K.Yu. Saleev, N.M. Salikhov, A.L. Shepetov, Yu.V. Shlyugaev, S.I. Svertilov, W.M. Thu, L.I. Vil’danova, N.N. Zastrozhnova, Z.S. Zhantaev, K.S. Zhilchenko, V.V. Zhukov, K.P. Zybin. Simultaneous observation of lightning emission in different diapasons of electromagnetic spectrum in Tien-Shan mountains. Atmospheric Research. V.211. 2018. P.73-84. https://doi.org/10.1016/j.atmosres.2018.04.018
- A. Shepetov, A. Chubenko, O. Kryakunova, N. Nikolayevsky, N. Salikhov, V. Yanke. The STM32 microcontroller based pulse intensity registration system for the neutron monitor. European Physical Journal (EPJ Web of Conf.), 145:19002, 2017. DOI: 10.1051/epjconf/201614519002
- V.A. Ryabov, A.M. Almenova, V.P. Antonova, R.U. Beisembayev, S.P. Bezshapov, A.S. Borisov, A.P. Chubenko, O.D. Dalkarov, A.V. Gurevich, A.N. Karashtin, O.N. Kryakynova, G.G. Mitko, R.A. Mukhamedshin, K.M. Mukhashev, R.A. Nam, N.F. Nikolaevsky, V.P. Pavlyuchenko, V.V. Piscal, V.O. Ptitsyn, V.S. Puchkov, N.O. Saduev, N.Kh. Sadykov, N.M. Salikhov, S.B. Shaulov, A.L. Shepetov, Yu.V. Shlyugaev, A.V. Stepanov, WM. Thu, L.I. Vildanova, M.I. Vildanova, N.N. Zastrozhnova, V.V. Zukhov, K.P. Zybin. Modern status of the Tien-Shan cosmic ray station. European Physical Journal (EPJ Web of Conf.), 145:12001, 2017. DOI: 10.1051/epjconf/201714512001
- A.V. Belov, O.N. Kryakunova, A.A. Abunin, M.A. Abunina, S.P. Gaidash, N.F. Nikolayevskiy, N.M. Salikhov, I.L. Tsepakina. Characteristic Behavior of High-Energy Magnetospheric Electrons from 1987 to 2007. Bulletin of the Russian Academy of Sciences: Physics, 2017, Vol. 81, No. 2, pp. 211–214. © Allerton Press, Inc., 2017. DOI: 10.3103/S1062873817020083
- A.P.Chubenko, A.L.Shepetov, V.P.Antonova, R.U.Beisembayev, A.S.Borisov, O.D.Dalkarov, O.N.Kryakunova, K.M. Mukashev, R.A.Mukhamedshin, R.A.Nam, N.F.Nikolaevsky, V.P.Pavlyuchenko, V.V.Piskal, V.S.Puchkov, V.A.Ryabov, T.Kh.Sadykov, N.O.Saduev, N.M.Salikhov, S.B.Shaulov, A.V.Stepanov, N.G.Vildanov, L.I.Vildanova, M.I.Vildanova, N.N.Zastrozhnova, V.V.Zhukov. The new EAS detector complex of the Tien Shan mountain cosmic ray station. Nuclear Instruments and Methods in Physics Research. A. 832. 2016. P.158-178.
- A.V. Gurevich, A.M. Almenova, V.P. Antonova, A.P. Chubenko, A.N. Karashtin, O.N. Kryakunova, V.Yu. Lutsenko, G.G. Mitko, M.O. Ptitsyn, V.V. Piscal, V.A. Ryabov, N.M. Salikhov, T.Kh. Sadykov, A.L. Shepetov, Yu.V. Shlyugaev, W.M. Thu, L.I. Vil’danova, N.N. Zastrozhnova, K.P. Zybin. Observations of high-energy radiation during thunderstorms at Tien-Shan. Physical Review. D 94. 023003. 2016.
- M. Papailiou, H. Mavromichalaki, M. Abunina, A. Belov, E. Eroshenko, V. Yanke, O. Kryakunova. Forbush Decreases associated with Western Solar Sources and Geomagnetic Storms: A Study on Precursors. Solar Physics. 2013. (DOI 10.1007/s11207-013-0231-x)
- O.Kryakunova, I.Tsepakina, N.Nikolayevskiy, A.Malimbayev, A.Belov, A.Abunin, M.Abunina, E.Eroshenko, V.Oleneva, V.Yanke. Influence of high-speed streams from coronal holes on cosmic ray intensity in 2007. Journal of Physics: Conference Series 409 (2013) 012181. (doi:10.1088/1742-6596/409/1/012181) IOP Publishing
- M Abunina, A Papaioannou, M Gerontidou, P Paschalis, A Abunin, S Gaidash, I Tsepakina, A Malimbayev, A Belov, H Mavromichalaki, O Kryakunova, P Velinov. Forecasting Geomagnetic Conditions in near-Earth space. Journal of Physics: Conference Series 409 (2013) 012197. (doi:10.1088/1742-6596/409/1/012197) IOP Publishing.
- O. Kryakunova, N. Nikolayevskiy, A. Malimbayev, O. Gontarev, Yu. Levin, O. Sokolova, A. Stepanov, A. Shepetov, I. Tsepakina. Kazakhstan Experimental Complex for Space Weather Investigation. Proceeding of the 32nd International Cosmic Ray Conference, August 11-18 2011, Beijing, China. V.11. P.305-308. (DOI: 10.7529/ICRC2011/V11/0788).
- A.V. Belov, E. A. Eroshenko, O. N. Kryakunova, V. G. Kurt, V. G. Yanke. Ground Level Enhancements of Solar Cosmic Rays during the Last Three Solar Cycles. Geomagnetism and Aeronomy. Vol. 50, No. 1, p.21-33, 2010.
- Mavromichalaki, H., Papaioannou, A., Plainaki, C., Sarlanis, C., Souvatzoglou, G., Gerontidou, M., Papailiou M., Eroshenko, E., Belov, A., Yanke, V., Flückiger, E. O., Bütikofer, R., Parisi, M., Storini, M., Klein K.- L., Fuller, N., Steigies, C. T., Rother, O. M., Heber, B., Wimmer – Schweingruber, R. F., Kudela, K., Strharsky, I., Langer, R., Usoskin, I., Ibragimov, A., Chilingaryan, A., Hovsepyan, G., Reymers, A., Yeghikyan, A., Kryakunova, O., Dryn, E., Nikolayevskiy, N., Dorman, L., Pustil’nik, L. Applications and usage of the real-time Neutron Monitor Database. Advances in Space Research, 47, 2011, p. 2210-2222. (doi:10.1016/j.asr.2010.02.019).
- Kryakunova O.N., Beisembaev R.U., Drobzhev V.I., Dryn E.A., Nikolaevskiy N.F. Identification of solar cosmic ray ground level enhancements at the middle latitudes. Proceedings of the 30th International Cosmic Ray Conference Rogelio Caballero, Juan Carlos D’Olivo, Gustavo Medina-Tanco, Lukas Nellen, Federico A. Sánchez, José F. Valdés-Galicia (eds.) Universidad Nacional Autónoma de México, Mexico City, Mexico, 2008. Vol. 1 (SH), pages 245-248.
- Belov A., Eroshenko E., Kryakunova O., Kurt V. and Yanke V. GLEs in the last three solar cycles. Proceedings of the 31st International Cosmic Ray Conference, Lodz, Poland, 7-15 July 2009, paper 0993.
- Belov A., Asipenka A., Dorman L., Eroshenko E. , Kryakunova O., Nikolayevsky N., Shepetov A., Yanke V., Zhang JiLong. A real-time search for solar neutron events in the data of high-altitude neutron monitors. Proceedings of the 31st International Cosmic Ray Conference, Lodz, Poland, 7-15 July 2009, paper 1107.
- R.U. Beisembaev, V.I. Drobzhev, E.A. Dryn, O.N. Kryakunova, N.F.Nikolaevskiy. Solar extreme events on the data of Alma-Ata neutron monitor: Identification of ground level enhancements. Advances in Space Research. V.43, pp. 509-514, 2009.
- A.G. Zusmanovich, O.N.Kryakunova, A.L.Shepetov. The Tien-Shan mountain cosmic ray station of the Ionosphere Institute of Kazakhstan Republic. Advances in Space Research. V.44, pp. 1194-1199, 2009.
- Belov A., Eroshenko E.A, Kryakunova O.N., Kurt V., Yanke V.G. X-ray Flare Characteristics and Probability of Solar Proton Events. Proceedings of the 30th International Cosmic Ray Conference Rogelio Caballero, Juan Carlos D’Olivo, Gustavo Medina-Tanco, Lukas Nellen, Federico A. Sánchez, José F. Valdés-Galicia (eds.) Universidad Nacional Autónoma de México, Mexico City, Mexico, 2008. Vol. 1 (SH), pages 167-170.
- Dvornikov V.M., Kravtsova M.V., Lukovnikova A.A., Sdobnov V.E., Belov A.V., Eroshenko E.A., Yanke V.G., Kryakunova O.N. Variations of parameters of rigidity spectrum of cosmic rays during events of January, 2005. Proceedings of the 30th International Cosmic Ray Conference Rogelio Caballero, Juan Carlos D’Olivo, Gustavo Medina-Tanco, Lukas Nellen, Federico A. Sánchez, José F. Valdés-Galicia (eds.) Universidad Nacional Autónoma de México, Mexico City, Mexico, 2008. Vol. 1 (SH), pages 155-158.
- Dvornikov V.M., Kravtsova M.V., Lukovnikova A.A., Sdobnov V.E., Kryakunova O.N. Forecast of the solar proton events according to the rigidity spectrum variations of cosmic rays. Proceedings of the 30th International Cosmic Ray Conference Rogelio Caballero, Juan Carlos D’Olivo, Gustavo Medina-Tanco, Lukas Nellen, Federico A. Sánchez, José F. Valdés-Galicia (eds.) Universidad Nacional Autónoma de México, Mexico City, Mexico, 2008. Vol. 1 (SH), pages 127-130.
- A.Belov, E. Dryn, E. Eroshenko, O. Kryakunova, V. Oleneva, V. Yanke, M. Papailiou. Behavior of the cosmic ray vector anisotropy near interplanetary shocks. Proceedings of 21st ECRS, Košice, Slovakia, 9 — 12 September 2008, p.347-350.
- A.Amurina, V.P.Antonova, G.M.Antova, A.P.Chubenko, V.I.Drobzhev, O.N.Kryakunova, S.V.Kryukov, A.L. Shepetov, et.all Current state of the ATHLET set-up at the Tien-Shan //Nuclear Physics B (proc.Suppl.) 151, 2006, p. 422-425.
- Amurina I.V., Autova G.M., Drobzhev V.I., Kryakunova O.N. et al. Modern State of the ATHLET Setup at the Tien Shan. International Journal of Modern Physics A.V.20, N29. 2005. P. 6778-6780.
- Belov A.V., Eroshenko E.A., Yanke V.G., Kryakunova O.N., Nikolaevskiy N.F. Space Weather Research: the Connection between Satellite Malfunction Data and Cosmic Ray Activity Indices. International Journal of Modern Physics A.V.20, N29. 2005. P. 6675-6677.
- Beisembaev R.U., Dryn E.A., Kryakunova O.N. Solar Neutrons and Information Criterion. International Journal of Modern Physics A.V.20, N29. 2005. P. 6672-6674.
- Belov A.V., Drobzhev V.I., Eroshenko E.A., Kryakunova O.N., Nikolaevskiy N.F., Yanke V.G. Zhantaev Zh.Sh. Space Weather Research by means of High Mountain Alma-Ata Neutron Monitor. Multi-Wavelength Investigations of Solar Activity. Proceeding of the 223th Symposium of the International Astronomical Union. Cambridge University Press, 2004. P. 543-544.
- Belov A., Dorman L., Iucci N., Kryakunova O., Ptitsyna N. The relation of high- and low-orbit satellite anomalies to different geophysical parameters.// in «Effects of Space Weather on Technology Infrastructure» edited by I.A. Daglis, Kluwer Academic Publishers, Dordrecht, The Netherlands, NATO Science Series II, 2004, Vol.176, pp. 147-163.
- Mavromichalaki H., Yanke V., Dorman L., Iucci N., Chilingaryan A., Kryakunova O. Neutron Monitor Network in Real Time and Space Weather Tasks.// in «Effects of Space Weather on Technology Infrastructure» edited by I.A. Daglis, Kluwer Academic Publishers, Dordrecht, The Netherlands, NATO Science Series II, 2004, Vol.176, pp.301-316. | physics |
https://davidshouseofdiamonds.com/blogs/blog/what-makes-diamonds-sparkle | 2023-09-23T07:22:28 | s3://commoncrawl/crawl-data/CC-MAIN-2023-40/segments/1695233506480.35/warc/CC-MAIN-20230923062631-20230923092631-00739.warc.gz | 0.935212 | 706 | CC-MAIN-2023-40 | webtext-fineweb__CC-MAIN-2023-40__0__141910102 | en | Diamond Initial Jewelry: The Perfect Gift May 10, 2023
Your Go-to Guide for Different Ring Setting Styles and Types March 24, 2023
What Makes Diamonds Sparkle?
When you think of a diamond, you think of a clear stone that glitters and sparkles in the light, but how does that happen? Diamonds don’t come out of the ground dazzling to the eye, it’s all about how they’re cut.
Diamonds Interact with Light
Those bright sparkles are caused by the light interacting with the various facets of the diamond. It’s not just light reflecting off the surface. Since the diamond is clear, the light actually enters the diamond and reflects off the interior facets or planes.
The light may be reflected directly, resulting in white light, which is referred to as brightness, or it may split and come out as a rainbow, which is referred to as fire. Moving the diamond around means the light reflects at different angles and this is what gives it that famous sparkle.
As you can imagine, the cut matters quite a bit with precious stones like this. It’s a mathematical procedure to slice the diamond just right so it will reflect the most light possible. The more facets on the diamond, the more it will glint in the light. So that means if you pick a single cut diamond with just 18 or so facets, it won’t seem nearly as amazing as one that has 58 facets, like a round brilliant cut diamond.
Selecting Diamonds for Their Quality
Not all diamonds are the same, so look at the grade before buying. A diamond rated Excellent for cut will offer the best contrast of light and dark, with a nice, even pattern overall. A Good cut grade indicates the diamond is not as bright and has some darkness inside the diamond. A Poor cut diamond will look dull and unappealing. While cheaper to buy Poor diamonds, it’s always best to pay for quality.
It’s also a good idea to pick a diamond with great clarity to ensure the most sparkle possible. The less clarity in the diamond, the harder it is for the light to pass through it and reflect correctly. Overall, a diamond that truly glitters is one that is high quality.
How to Get the Best Sparkle
If you still aren’t happy with the amount of sparkle you’re getting from a single diamond, why not multiply them? Jewelry with multiple gems will have more facets and therefore more shine.
Even the way the diamond is set in a ring or earring will affect how it shines. Look for minimal settings, preferably prongs, to avoid the setting from blocking light. You want as much light as possible getting inside the diamond so it can really show off.
When you buy a diamond, you should get what you envision. That sparkling stone that perfectly reflects the light from dozens of facets and lights up the world should be yours. It’s rare that people are happy with poorly cut or low-quality diamonds, just because it can be so obvious that they’re not high quality.
Take the time to find the right diamond for your needs. It’s an investment that will make you happy for a lifetime.
Are you ready to invest in a quality diamond or custom engagement ring? Check out our diamond jewelry choices today. | physics |
http://www.wonderclub.com/WorldWonders/LightsHistory.html | 2019-03-21T14:32:35 | s3://commoncrawl/crawl-data/CC-MAIN-2019-13/segments/1552912202525.25/warc/CC-MAIN-20190321132523-20190321154523-00152.warc.gz | 0.92857 | 780 | CC-MAIN-2019-13 | webtext-fineweb__CC-MAIN-2019-13__0__2993024 | en | Northern lights, or Aurora borealis brings together two mythological deities - Aurora, the Roman goddess of the dawn, and Boreas, Greek god of the north wind - to describe an event witnessed mostly at night in the high northerly latitudes. An identical phenomenon, the aurora australis, occurs in the high latitudes of the Southern Hemisphere, a region that has always been much more sparsely inhabited than the planet's northern reaches. Only a few eyewitness accounts of the aurora australis were available before 20th-century explorers arrived in Antarctica.
By contrast, the flowing ribbons, sky-filling swirls, otherworldly glow, gossamer veils, and brilliant rays of the aurora borealis are a regular presence that has awed and terrified northern peoples for thousands of years. To Finns the aurora was "fox fire" sparked by glistening fur. Some Alaskan Inuit saw the dancing souls of deer, seals, salmon, and beluga; others believed that if they whistled the lights might snatch them away. The Athabascan saw messages from their dead, the "sky dwellers."
For a long time, scientists offered almost as many interpretations of the northern lights as did the traditional peoples who observed them. The 20th century has brought with it studies of the earth's magnetism and the sun's workings. The aurora arises in the roiling turbulence of the sun. More than 100,000 times hotter than boiling water, the sun's interior chops the atoms that form solar gases into a thin stream of electrically charged particles - protons and electrons. Both matter and energy, this stream continuously erupts from the sun and is called the solar wind. Two or three days after bursting from the sun's surface at speeds of up to 500 miles a second, the solar wind reaches the earth, 93 million miles away.
The solar wind has the force to swiftly annihilate life on earth. What stops it from doing so is the shielding power of the planet's magnetic field, reaching out more than 40,000 miles into space. Like the earth, the sun is also a mighty magnet, and the solar wind carries fragments of its magnetic field. As solar particles crash into the planet's magnetic field, the fields repel each other.
Though most of the solar wind harmlessly sideswipes the magnetic shield, small streams of solar particles do manage to become trapped, spiraling down toward the planet's north and south magnetic poles. As they tumble, beams of electrons spread, ripple, and swirl, and yet their movements remain invisible. But when the solar wind hits the upper reaches of the ionosphere and encounters atmospheric gases, it starts churning the thin soup of oxygen and nitrogen there. Marvelous shapes and flowing patterns begin to appear. Electrons bouncing around among atoms of oxygen create a greenish glow much lower. Nitrogen molecules hit by solar wind may shine bright pink, or blue and violet, depending upon their distance from the surface.
The ever changing dance of lights belies the aurora's permanence. Though only parts of it can be seen at any time, and almost never during the day, the aurora borealis forms a 2,000-mile-wide auroral oval above the magnetic north pole day in and day out, year after year.
What can dramatically change the oval are the occasional spikes in solar activity that turn the solar wind into a raging hurricane. Then, for a few days, the auroral oval flows toward the Equator and treats sky-gazers as far south as Mexico to midnight extravanganzas. At the same time, electromagnetic disturbances intensify, with overloaded power lines and scrambled communications serving to remind us of the force behind the celestial fireworks.
Source: The Wonders of the World, National Geographic Society | physics |
http://www.citd.eu/home-en/ | 2018-05-26T08:00:24 | s3://commoncrawl/crawl-data/CC-MAIN-2018-22/segments/1526794867374.98/warc/CC-MAIN-20180526073410-20180526093410-00391.warc.gz | 0.954278 | 270 | CC-MAIN-2018-22 | webtext-fineweb__CC-MAIN-2018-22__0__95334933 | en | Second day at Space Tech in Pasadena. We are happy to explain what are our approach about additive manufacturing challenges and also the digitization. We are at booth 9306 see you there. http://www.spacetechexpo.com/
CITD is an engineering company dedicated to the design and stress of systems and structures in aerospace, industrial and energy sectors, and in full swing with infrastructures.
With more than 15 years of successful projects, the CITD team continues providing their expertise and knowledge in the definition of big projects in aeronautics and defence for large aircraft manufacturers such as Airbus Group, and is also involved in the design of nuclear fusion components and physics of particles for CERN or Fusion for Energy.
Thanks to experience acquired, the work is done with high quality standards. The satisfaction of our clients, added to our forward-looking spirit, daily encourages us to implement improvements and undertake innovative projects.
Our best achievement is to continue working with companies such as Airbus on complex projects. We feel comfortable carrying out our deliverables because we treasure a large experience gained over the years in civil aircraft programs like the A380, A350, A310-330 family and also military programs like the A400M or tanker conversions of the A330 RAAF, FSTA and MRTT. | physics |
https://unitedlifestyle.pk/what-kind-of-blinds-to-use-in-winter/ | 2024-04-17T14:55:10 | s3://commoncrawl/crawl-data/CC-MAIN-2024-18/segments/1712296817158.8/warc/CC-MAIN-20240417142102-20240417172102-00445.warc.gz | 0.952168 | 318 | CC-MAIN-2024-18 | webtext-fineweb__CC-MAIN-2024-18__0__200598689 | en | As the winter are approaching, you would want to spend more time working in a warm and cozy environment. For the required warmth the use of heating equipment increases. One might want to cut the heating costs and move towards more conventional methods for keeping their homes warm. This can be achieved by covering your windows in order to keep the home warm and cozy. When we talk about covering the windows in winter, the most important question that needs to be answered is what kind of blinds to use.
The best and most effective blinds are cellular shades. When two layers of fabric are bonded together in order to form honeycomb-like pockets, it forms cellular shades. The fabric pockets are effective for trapping air. The trapped air limits the heat from transferring through the window. The entire phenomenon slows down the radiant heat loss and increases the R-value by 3.5%.
Draper panels with thermal lining will block the cold air from sliding in. the thermal lining will not only help with retaining heat but also protect the outside-facing fabric from the damages that may be caused by UV rays. Mounting them closer to the ceiling for them to reach the floor is most effective. Using the wrap-around hardware will help to add further protection. Drapery also wins at providing style.
When the two of these are paired together, there is ensured protection against wintry and cold air. Other options may include louvered blinds. These are horizontal slat-type blinds and are effective as well. These not only keep the home warm by retaining heat but also reduce glare. | physics |
https://www.rikeshkkpatel.co.uk/review/micsig-dp10007-differential-probe/ | 2023-11-30T21:23:01 | s3://commoncrawl/crawl-data/CC-MAIN-2023-50/segments/1700679100232.63/warc/CC-MAIN-20231130193829-20231130223829-00420.warc.gz | 0.940318 | 583 | CC-MAIN-2023-50 | webtext-fineweb__CC-MAIN-2023-50__0__192730341 | en | I first came across high voltage differential probes over ten years ago when I was doing some work to understand the noise present on the 630 V DC traction current used on the London Underground. Since then I’ve always wanted to have one in my own toolkit but was put off by the price until I came across the Micsig DP10007.
The probe and all its accessories come in a compact travel case which I like as it keeps everything together – less chance for me to misplace anything.
When you open it there are foam cut-outs to keep everything secure and protected.
The probe comes with alligator clips, test probes and test hooks – enough for most applications.
Next to the BNC flying lead there is a USB-B socket which you connect the supplied cable to power the device from a USB-A port. There are two rubber buttons on the front of the probe to set its attenuation at either x10 or x100. When the device is powered one of the buttons will illuminate green to show the currently set attenuation. There’s a USB-A socket on the side of the probe – this is a pass-through for power only not data.
The maximum differential voltage this probe can measure is 700V with a bandwidth of 100MHz. I don’t have the equipment to test the probe at its limits but to make sure it worked I connected it to my controllable outlet.
In the UK the mains electricity runs at a nominal 230VRMS and 50Hz. In order to stay within the limits of my oscilloscope’s voltage range I set the attenuation to x100. The scope trace below shows what the mains voltage looks like when the outlet is switched ON. As you can see it’s not a perfect sinewave, but close enough, with an average voltage and frequency of 230VRMS and 49.95Hz respectively.
If you want to learn more about mains electricity in the UK head over to mainsfrequency.uk.
The solid state relay fitted in my controllable outlet uses a TRIAC which means it only switches ON or OFF at a zero-crossing. The trace below shows the output when I toggle the relay at 100Hz. You can see that initially the top half of the cycle is suppressed as expected. Eventually as the actual mains frequency is slightly less than 50Hz this flips and the bottom half is then suppressed.
I’m not able to test the accuracy of this differential probe and this is where paying money for some of the more expensive probes pays off but I’m only planning to use it for my own personal projects so this is more than enough for me.
If you interested in getting one there only seem to be a handful of retailers in the UK and I ended up buying mine from here. | physics |
https://designeroptics.com/blogs/faqs/why-are-people-wearing-polarized-lenses | 2021-03-05T13:57:40 | s3://commoncrawl/crawl-data/CC-MAIN-2021-10/segments/1614178372367.74/warc/CC-MAIN-20210305122143-20210305152143-00188.warc.gz | 0.929668 | 578 | CC-MAIN-2021-10 | webtext-fineweb__CC-MAIN-2021-10__0__126241757 | en | When’s the last time your eyes got caught by a stray glare from a passing car, a phone screen in a coffee shop, or a sparkling lake surface? Our eyes are meant for gathering light and registering the world around us, but even that can backfire. Flat surfaces like the aforementioned can cause rays of sunlight to shine directly into your retinas, and we shouldn’t have to tell you that it’s harmful- it feels harmful! The exposure to UV light is already problematic, but prolonged exposure can bring along with it damage to your cornea, retinas, and other eye tissues.
How Do Polarized Lenses Work?
Light itself is bouncing from a thousand different angles and surfaces in any given location. The problem is when waves of light meet a horizontal surface and reflect it at a similar angle. This results in a glare, but at the same time allows us to manage the problem with the correct lenses! Polarized glass only permits vertically-angled light to pass through, eliminating the harsh reflections that plague us daily.
Glare brings strain to your eyes and heightens the risk of encountering hazards and missing important visual details. Whether it’s a day at the lake or a long drive through the city, you can experience fatigue from the constant sunlight throughout your day. On top of this, contrast and clarity of vision is lost as brightness increases. Easily combated by polarized lenses, you can regain the comfort and true colors of your life by obtaining a specialized pair.
How Do I Tell If I Have Polarized Lenses?
Just bought a pair and need to check to see if they pass the polarized test? If they still have the sticker, tilt the glasses (facing you) onto their side about 60 degrees. Did the sticker get darker? You’re good to go!
Have an old pair and want to check? Grab another pair and put it behind the first. Rotate the first pair 60 degrees onto its side. If the overlapping lense becomes darker you have a polarized lense.
Only got one pair? Again rotate a pair 60 degrees in front of a computer screen, and if it proceeds to darken, you’re all set.
Why Should I Get Polarized Lenses?
Truthfully there are very few (if any) downsides to rocking a pair of specialized lenses. Protection from UV light along with cancelling out glare is a win-win in anybody’s book. While they can make reading LCD screens slightly more difficult, as long as that isn’t your job all day, you’ll be in the clear. You are protecting your cornea and retina from permanent damage, while also ditching the annoyance and inconvenience of reflections throughout your day! Take advantage of a life with better vision, colors, and comfort. | physics |
http://tarleton.edu/waco/degrees/bs-engineering-physics.html | 2015-11-25T20:20:11 | s3://commoncrawl/crawl-data/CC-MAIN-2015-48/segments/1448398445679.7/warc/CC-MAIN-20151124205405-00356-ip-10-71-132-137.ec2.internal.warc.gz | 0.866734 | 108 | CC-MAIN-2015-48 | webtext-fineweb__CC-MAIN-2015-48__0__51042250 | en | The Engineering Physics program at Tarleton State University is accredited by the Engineering Accreditation Commission of ABET (www.abet.org). This is a four-year engineering degree that provides a student with the opportunity for employment as an engineer in the high paying, high technology fields related to electrical, computer, and semiconductor industries. The program also prepares the student for graduate study in either engineering or physics.
Face-to-Face, Blended, Online
University Center at McLennan Community College
Contact InformationDr. Denise Martinez | physics |
http://www.kazuoresources.co.za/sectors/water-reservoirs/ | 2017-04-23T15:47:23 | s3://commoncrawl/crawl-data/CC-MAIN-2017-17/segments/1492917118713.1/warc/CC-MAIN-20170423031158-00323-ip-10-145-167-34.ec2.internal.warc.gz | 0.92834 | 286 | CC-MAIN-2017-17 | webtext-fineweb__CC-MAIN-2017-17__0__38107242 | en | Evaporation control through using modular floating water surface covers
Euro-Matic floating ball blankets provide highly effective solutions to difficult liquid storage problems. By placing a sufficient quantity of floating balls onto the surface of a liquid, the balls automatically arrange themselves into a close packed formation over 91% of the surface area. Such a high surface coverage provides an extremely effective barrier and significantly reduces the mass and heat transfer mechanisms operating between the liquid and surrounding environment.
A thermal insulation barrier is achieved through the air held in each ball and the poor heat conductivity of plastic. The air pockets between the balls, although not sealed, also contribute to this cellular insulation system which dramatically reduces heat loss.
The low liquid surface area exposed to atmosphere dramatically reduces liquid loss through evaporation, odor release to the atmosphere and conversely prevents surface absorption of oxygen.
Yet a blanket of Euro-Matic balls presents no impediment to product dipping or equipment which has to move through the liquid surface; the balls are pushed aside, but quickly reform their cover as the equipment moves forward or products are lifted away from the tank. The balls will rise and fall with liquid level within storage tanks, and also provide a constant cover over liquids held in reservoirs with sloping sides. If the liquid level falls, causing the surface area to shrink, the balls simply stack in a double layer; they automatically spread themselves into a single layer again as the level rises. | physics |
https://www.jkacademypro.com/std-5-science-our-earth-and-the-solar-system-question-and-answer/ | 2021-05-11T06:29:52 | s3://commoncrawl/crawl-data/CC-MAIN-2021-21/segments/1620243991904.6/warc/CC-MAIN-20210511060441-20210511090441-00178.warc.gz | 0.900713 | 1,600 | CC-MAIN-2021-21 | webtext-fineweb__CC-MAIN-2021-21__0__153768688 | en | Chapter 1: Our Earth and Our Solar System
1. What’s the solution? One of the asteroids has fallen out of its place in the asteroid belt and is hurtling towards the sun. Our earth is in its way and there is all likelihood of a collision. What can be done to prevent this collision?
2. Use your brain power!
(1) What will happen to our solar system if the sun were to suddenly disappear?
(2) Suppose you want to give your address to a friend you have on the planet Mars. How will you write your address if you want them to understand exactly where you live?
3. Name the planets in their sequential order?
4. Who am I?
(a) You can see me from the earth but the lighted part of me that you see changes every day.
(b) I have my own light. It is only from me that the planets get light and heat.
(c) I turn around myself, around a planet and also around a star.
(d) I turn around myself and revolve around the sun.
(e) No other planet has a living world like mine.
(f) I am the nearest star to the earth.
5.(a) For what purpose are rockets used in space travel?
(b) What information do man-made satellites provide?
Fill in the blanks:
1) _________________ are very far away from the earth.
2) The sun, the moon, the stars, the planets, etc. are all known as ________________________ .
3) The heavenly bodies that twinkle are called _____________________.
4) Stars have their own _________________ .
5) The sun is a _________________ .
6) The Sun appears big and brilliant because it is _________________ to us than any of the other stars.
7) We cannot see other stars during the day because of the bright light of the _________________.
8) The heavenly bodies that do not twinkle are called _________________ .
9) Planets do not have _________________ of their own _________________ .
10) Planets get light from the _________________ .
11) Planets revolve around a _________________, even as they rotate around themselves.
12) Our earth is a _________________.
13) The earth gets its light from the _________________.
14) The earth moves around the _________________.
15) Its movement around the sun is called the _________________of the earth.
16) The sun, which is a star, and the planets that revolve around it are together called the
17) Besides the planets, the solar system also includes various other _________________.
18) Our _________________is filled with heavenly bodies like the Sun, our eight planets, dwarf planets, dozens of moons and millions of asteroids, comets and meteoroids.
19) Some heavenly bodies that revolve around planets called _________________.
20) Satellites get their light from the _________________.
21) The moon revolves around the _________________.
22) Some smaller heavenly bodies that revolve around the sun are called
23) There is a band of numerous small heavenly bodies between the planets Mars and Jupiter are called _________________.
24) Asteroids also revolve around the _________________.
25) Compared to the sun, other heavenly bodies in the solar system are much _________________.
26) All heavenly bodies exert a force of attraction or a pull on one another.
This force is called the force of _________________.
27) Due to the earth’s _________________, all things on the earth remain on it.
28) Even if we throw something upwards with great force, it finally falls down to the ground. This is because of _________________.
29) The emptiness between and beyond the stars and planets is called _________________.
30) To send some object from the earth into space, it must be given power against the force of _________________.
31) _________________technology or space launch technology is used in order to send any object away from the earth.
32) Man-made _________________ provide useful information for agriculture, environment, weather forecasting, making maps, and searching for water and mineral wealth on the earth.
33) Man-made satellites are also used for _________________.
34) ISRO means __________________________________ .
35) On 22 October 2008, the Indian Space Research Organization, ISRO, launched a spacecraft to the moon. The mission is known as _________________.
36) _________________ is known as M.O.M. or Mars Orbit Mission.
37) __________________________ was launched on 5 November 2013.
38) Scientists who travel in the spacecraft are called ________________________.
39) _________________ became the first Indian astronaut to go into space in 1984.
40) He spent eight days on a space station for a joint mission of the ISRO and the
41) Seeing India from space, he said that it looked _______________________________________.
Answer the following questions:
1) What are heavenly bodies?
2) Why can we see the round shape of the moon clearly?
3) What are stars?
4) Why does the sun appear big and brilliant?
5) What are planets?
6) From where does the earth get its light?
7) What is the movement of the earth around the sun called?
8) How many planets revolve around the sun? Name them?
9) What is an orbit?
10) What is the Solar system?
11) What are satellites?
12) Name the satellite of the earth?
13) Why is the moon, called the satellite of the earth?
14) Which planets in our solar system have natural satellites?
15) What are man-made or artificial satellites?
16) Why are man-made or artificial satellites launched into space?
17) What are dwarf planets?
18) Name a dwarf planet in our solar system?
19) What are asteroids?
20) Where do find the asteroids?
21) Which planet is nearest to the sun?
22) At what position is the earth from the sun?
23) Which planet is placed between the earth and Mercury?
24) Name the planets beyond the orbit of Mars in serial order.
25) Which planet in the solar system is furthest from the sun?
26) What is gravity?
27) Why do the planets move in around the sun in their fixed orbits and do not move out?
28) Why do all the things remain on the earth and not fall out of it?
29) Even if we throw something up with great force it finally falls down to the ground. Why?
30) What is space?
31) What technology is used to send object into outer space?
32) How does the Diwali firecracker – ‘rocket’ work?
33) How are rockets sent into space?
34) Who are astronauts?
35) Who is the first Indian to travel into space?
36) In which year did Rakesh Sharma travel into space? How many days did he spend there?
37) What words did Rakesh Sharma use to describe India from space?
38) What is Chandrayaan-1?
39) What is the other name for Magalyaan?
40) When was Magalyaan launched into space?
41) When did Magalyaan get established in an orbit of Mars
42) Why was Magalyaan launched into space?
For PDF click on the link. | physics |
http://thatjoliegirl.com/crafts/?p=269 | 2021-01-27T09:28:35 | s3://commoncrawl/crawl-data/CC-MAIN-2021-04/segments/1610704821381.83/warc/CC-MAIN-20210127090152-20210127120152-00656.warc.gz | 0.987293 | 163 | CC-MAIN-2021-04 | webtext-fineweb__CC-MAIN-2021-04__0__63014630 | en | The art at the SE Area Art Walk was just superb this year. My favorite artist of the day was Brian Crane. His tactile kinetic art is the most amazing thing I've seen in ages. The piece above will travel down this ramp at the slightest touch. It is easily hours and hours of entertainment. We were spellbound.
This ball of screws is pliable. When you put your hand over the ball and lightly squeeze, the screws move in your hands. It's a crazy sensation. Brian happily chatted with us about how he came up with his ideas. He was such a nice guy and you could see how joyous his art made him.
Videos of these pieces in motion are posted on his web-site. It's definitely a site to check out. His ideas are limitless. | physics |
http://www.huntsvillephotographicsociety.org/news/articles/lastest-events/solar-eclipse-planning-jim-gardepe | 2018-01-18T19:44:31 | s3://commoncrawl/crawl-data/CC-MAIN-2018-05/segments/1516084887600.12/warc/CC-MAIN-20180118190921-20180118210921-00083.warc.gz | 0.927895 | 377 | CC-MAIN-2018-05 | webtext-fineweb__CC-MAIN-2018-05__0__33916474 | en | Here's some information Jim Gardepe wanted to share about the solar eclipse.
These points are important for people who want to observe and/or photograph the total solar eclipse on August 21, 2017. These steps should be taken as soon as possible.
1. Plan your viewing location. This is a map of the total solar eclipse as it crosses KY, TN, and NC.
http://www. eclipse2017.org/2017/maps/ky- tn-nc.gif
2. Plan your lodging. Hotels along the eclipse path are being booked fast, and hotels are going to jack up rates nearer eclipse day. Arrival at your viewing location a day early is recommended, as traffic on eclipse day could be bad, and you need time to set up.
3. Get your leave approved NOW, as the eclipse is on a Monday.
4. Order eclipse viewing glasses. These are for direct viewing only, not for photography. They might sell out as eclipse day approaches. Everyone will need a set.
https://www. greatamericaneclipse.com/ store/
https://www. rainbowsymphony.com/eclipse- glasses/
5. Order solar filters for your camera/binoculars/telescope. These are essential for photography, and there is NO SAFE work-around using ND filters or any other jury-rig.
http://www. thousandoaksoptical.com/solar. html
https://www. rainbowsymphony.com/solar- filters/
6. Start practicing for the eclipse by photographing the moon, especially when the moon is high in the sky (near meridian), and when the moon is a crescent. Get used to operating your camera in the dark, as flashlights are not welcome at eclipse viewing sites. | physics |
https://www.realhealthynews.com/lower-wavelength-uv-light-kills-covid/ | 2020-10-20T02:25:04 | s3://commoncrawl/crawl-data/CC-MAIN-2020-45/segments/1603107869785.9/warc/CC-MAIN-20201020021700-20201020051700-00516.warc.gz | 0.917054 | 353 | CC-MAIN-2020-45 | webtext-fineweb__CC-MAIN-2020-45__0__69460337 | en | Ultraviolet (UV) rays kill the new coronavirus. They can also kill or damage human cells. However, Japanese researchers from Hiroshima University have found that lower-wavelength UV rays (in the form of far-UVC light) can kill the virus without harming humans.
Regular UV light has a wavelength of 254 nm and can irradiate human tissue, harming eyes and skin. However, UVC light, at wavelength of 222 nm, is just as germicidal as regular UV light but cannot penetrate the eyes or skin. Light in the range of 207-222 nm is called far-UVC.
In the study, published in the American Journal of Infection Control, the researchers applied UV light to lab samples containing the SARS-CoV-2 virus using a Care222 krypton-chloride excimer lamp from Ushio. This lamp provides 222-nm UV rays. After 30 seconds of exposure, the light killed 99.7% of the viral particles. A June 2020 study from Columbia University also found that far-UVC light set between 207 and 222 nm could kill up to 90% of coronaviruses and other pathogens in 8 minutes.
Because far-UVC light isn’t harmful, it could be used not only to sterilize work areas in hospitals. To stop seasonal viruses, it also could be used in “overhead far-UVC lamps” hung in public spaces. According to the Hiroshima University researchers, far-UVC also destroys the H1N1 influenza virus.
Disclaimer: This article does not provide medical advice. Do not take action based solely on this article and always consult with an appropriate healthcare professional. This article is purely for informational purposes. | physics |
https://biobridge.ru/en/news/1 | 2020-09-20T03:23:56 | s3://commoncrawl/crawl-data/CC-MAIN-2020-40/segments/1600400193391.9/warc/CC-MAIN-20200920031425-20200920061425-00124.warc.gz | 0.938956 | 397 | CC-MAIN-2020-40 | webtext-fineweb__CC-MAIN-2020-40__0__199592895 | en | Selection of projects for the biobridge-2019 acceleration program completed
On July 25, 2019, the SelectionDay – the final stage of selection of the strongest projects for the biobridge-2019 acceleration program – took place at the ASI Boiling Point in Moscow. In total 15 teams were invited to the SelectionDay, and during the pitch session they presented their research works to the expert judging panel which included representatives of the Industrial Union of Neuronet, MIPT, RVC JSC, Skolkovo Ventures, RDIGroup, ChemRar Group, under the chairmanship of the executives of the ChemRar Group and RDI Group Andrey Ivashchenko and Dmitry Aksenov and the Head of the expert council of the biobridge-2019 Alexander Melerzanov, Vice-Principal of Phystech school of biomedical physics of MIPT.
All the participating projects passed a preliminary face-to-face and virtual expert evaluation and consultations with the branch specialists, and 12 teams were selected for the accelerator following the SelectionDay results.
Projects pitch session
The SelectionDay comprised two stages:
>A speech with a presentation before experts and other participants and a questions and answers session,
> A poster session. All the participants of the event were able to come close to each project individually and ask questions of interest.
Experts discussing projects with teams during the poster session
Afterwards a meeting of the judging panel took place where the experts chose the projects to be included into the acceleration program.
During the following 1.5 months the teams will face an intensive work on preparation and "packing" of projects in order to obtain investments, and this work is aimed at data collection and validation, elaboration of missing elements individually for each project, structuring and preparation of speeches including in English on demo days in Moscow and Vienna. Congratulations to the teams that passed the selection. This is only the beginning! | physics |
https://premiumplumbers.ca/water-heater-anode-rod/ | 2023-12-11T15:11:00 | s3://commoncrawl/crawl-data/CC-MAIN-2023-50/segments/1700679515260.97/warc/CC-MAIN-20231211143258-20231211173258-00302.warc.gz | 0.882002 | 878 | CC-MAIN-2023-50 | webtext-fineweb__CC-MAIN-2023-50__0__123595607 | en | What is an Anode?
A water heater anode rod is a slender metal rod that is inserted into the water heater’s tank. Its role is to attract corrosive elements in the water. It sacrifices itself to prevent those elements from corroding the tank. An anode rod is a vital part of your water heater. It quietly works to extend the water heater’s lifespan and protect it from corrosion. If you maintain the hot water tank anode properly, it makes a big difference in the water heater’s longevity.
What is an Anode?
An anode is an electrode or component used in electrochemical processes and found in batteries and other chemical reactions. In a water heater, an anode is a metal rod typically made from materials like aluminum. It is inserted into the water heater’s tank.
Material of Anode Rod:
Anode Rods are made from three metals: magnesium, aluminum, or zinc. Each metal has its advantages and is chosen based on the specific water conditions in your area. Magnesium anode rods are ideal for soft water; aluminum anode rods are suited for harder water while zinc anode rods offer broad protection.
How Anode Rods Are Used:
The anode rod employs a process called “electrochemical cathodic protection.” Simply put, it is a magnet for corrosive elements in the water. It draws away corrosion from the tank’s interior walls. As the anode rod corrodes over time, it forms a protective layer, shielding the tank from deterioration and protecting it to remain rust-free.
Here’s the information about how hot water tank anode rods are used:
- Anode rods are inserted into the water heater’s tank.
- They attract corrosive elements present in the water and form a protective layer on its surface.
- They are preventive measures to avoid leaks, inefficiency, and premature water heater failure.
- Anode rods help maintain the tank’s structural integrity.
- Regular anode rod inspection and replacement are essential to establish protection.
How frequently should you inspect and change the Anode Rod?
The frequency of checking and replacing the anode rod in your water heater depends on various factors, including the type and quality of the water.
Here are some guidelines to help you determine the best schedule for checking and replacing the anode rod:
Annual Inspection: It’s a good practice to inspect the anode rod once a year visually. Check for signs of corrosion. If you notice the anode rod is heavily corroded and has lost a substantial amount, consider a replacement.
Water Quality: If you have “soft” water the anode rod may corrode more quickly due to the absence of minerals. In such cases, more frequent inspections and replacements might be necessary.
Local Water Conditions: The mineral content and pH of your local water supply can affect the rate of anode rod corrosion. Water with higher mineral content or a lower pH may cause the anode rod to corrode faster. In such cases, you might need to replace the anode rod more often.
Professional Inspection: Consider having a professional plumber inspect your water heater and anode rod during routine maintenance visits. A plumber can provide expert advice on the condition of the anode rod.
How to Maintain the Longevity of an Anode Rod?
Preserving an anode rod is essential to establish its effectiveness in protecting your water heater. Here’s how you can maintain and prolong the life of an anode rod:
Flush Sediments: Drain and flush your water heater to remove sediment buildup. Sediments can accelerate anode rod corrosion by providing a conducive environment for chemical reactions.
Adjust Water Heater Temperature: Lower the temperature setting on your water heater. Extremely high temperatures can increase the rate of anode rod consumption and overall tank corrosion.
Choose the Right Material: Depending on your water quality choose the appropriate type of anode rod to provide the best protection for your specific conditions.
Regular Inspection: Check the anode rod at least once a year. Look for signs of corrosion and significant wear on the rod’s surface. Early detection of decay allows for timely replacement. | physics |
http://www.021htajls.com/news/250.html | 2020-02-25T11:41:35 | s3://commoncrawl/crawl-data/CC-MAIN-2020-10/segments/1581875146066.89/warc/CC-MAIN-20200225110721-20200225140721-00223.warc.gz | 0.8092 | 649 | CC-MAIN-2020-10 | webtext-fineweb__CC-MAIN-2020-10__0__180770676 | en | What is a high temperature wire ?
High temperature wire is a kind of high temperature resistant wire, usually using solid core or stranded silver-plated or nickel-plated copper wire.
1. Working temperature: -80 ～ + 250 ℃; short-term resistance to 300 ℃.
2. Conductor: solid core or stranded silver-plated or nickel-plated copper wire
3. Insulation: PFA Teflon
4. Color: red / yellow / blue / white / black / yellow / green / brown / orange / purple / green / etc
Features / Use
It has corrosion resistance, oil resistance, strong acid resistance, strong alkali resistance, strong oxidant, etc .; has electrical insulation performance, high voltage resistance, low high frequency loss, non-moisture absorption, large insulation resistance; excellent flame resistance, aging resistance, use long life.
In the electronics industry, it can be used for temperature compensation wire, low temperature resistant wire, high temperature heating wire, aging resistant wire and flame retardant wire; in the household appliance industry, it can be used in air conditioners, microwave ovens, electronic disinfection cabinets, electric riceburgers, electronic thermos bottles, electricity Internal wiring of heaters, electric ovens, electric woks, lamps and lighting.
Naming rules for high-temperature wires
1. What is included in the product name
(1) Product application or size
(2) Product structural materials or types;
(3) Important or additional features of the product
The names are basically in the above order, and sometimes in order to emphasize important or additional features, the features are written before or before the corresponding structural description.
2. Order of structure description
Product structure description is based on the principle from inside to outside: conductor-> insulation-> inner sheath-> outer sheath-> armor type.
In the case of no confusion, some structural descriptions are omitted or abbreviated. For example, aluminum conductors are not allowed in automobile wires and flexible wires, so the conductor materials are not described.
Material of high temperature wire
1. Wires of heat-resistant material: refers to the insulation and protective cover material. The main resin has heat resistance. The main varieties are: polyurethane (up to 155 ° C), polyester (up to 135 ° C), polyvinylidene fluoride ( 150 ℃) and nylon (up to 115 ℃) insulation or sheath material
2. Ordinary materials are modified by various methods to achieve heat resistance: heat-resistant modification of rubber materials (up to 135 ° C), modification of polyvinyl fluoride wires (90 ~ 120 ° C), modification of polyethylene cables And other properties (105 ~ 150 ℃).
Application of high temperature wires
High-temperature wires are mainly used in communications, automobiles, motors, construction and other industries, such as mobile flexible wires, rubber-insulated soft power cables, control wires, heat-resistant building wires, automotive wires, aviation wires, locomotive wires, electrical and electrical lead wires Wait. | physics |
https://www.starboxinc.com/pages/starbox-how-insulation-works | 2023-10-04T10:36:17 | s3://commoncrawl/crawl-data/CC-MAIN-2023-40/segments/1695233511364.23/warc/CC-MAIN-20231004084230-20231004114230-00493.warc.gz | 0.914966 | 370 | CC-MAIN-2023-40 | webtext-fineweb__CC-MAIN-2023-40__0__158564488 | en | StarBox: How Insulation Works
Cold-Chain Challenges Explained
Insulation works by slowing the transfer of heat which can move in three ways: conduction, convection and radiation. Understanding the influence of these three methods allows one to make better and more informed choices.
Controlling convection is the most overlooked element in cold-chain shipping. Often taken for granted, closing the lid on an EPS cooler traps a certain amount of air within the container. By reducing the air space in a container you reduce convection and improve performance.
Slowing conduction is the primary role of insulation. Most thermal shipping materials (EPS, FPF, PET, denim, rock wool, etc) have comparable performance slowing conduction.
Radiation is a method of heat transfer that does not rely upon any contact between the heat source and the heated object as is the case with conduction and convection. Heat is transmitted though empty space by thermal radiation (infrared radiation), a type electromagnetic radiation . No mass is exchanged and no medium is required in the process of radiation. Examples of radiation is the heat from the sun, or heat released from the filament of a light bulb.
Matte black surfaces absorb the most thermal radiation while mirrors absorb the least. If the mirror surface is dusty or in contact with a material with higher emissivity (ability to absorb) such as cardboard, that material will conduct the absorbed heat to the mirror surface, defeating all radiation insulation benefits.
Radiation is the least influential method of heat transfer when it comes from thermal shipping. Even in the most extreme environments, heat gain comes primarily from the convection currents of air around the package conducting heat on to the surface of the package. | physics |
http://littleshelltribe.us/2016/06/22/how-does-a-pressure-cooker-work/ | 2018-05-27T04:58:36 | s3://commoncrawl/crawl-data/CC-MAIN-2018-22/segments/1526794868003.97/warc/CC-MAIN-20180527044401-20180527064401-00085.warc.gz | 0.925128 | 874 | CC-MAIN-2018-22 | webtext-fineweb__CC-MAIN-2018-22__0__40522838 | en | Normal water boils at 100 ° C at a pressure of 1 bar (= 100 kPa), the average air pressure at sea level. If boiling water once in an ordinary open pan (if the water has not evaporated), the temperature will not rise further. The extra added energy from the heat source (e.g., gas burner) provides evaporation of the water in the form of steam. It is a further waste of energy to allow the burner to burn harder than necessary to keep the water to the boil. By putting a lid on the heat loss is reduced and can be saved even more energy. There will always be escaping steam.
In a best pressure cooker‘s lid closed so that it can no longer just. The pressure will increase in the pan. The boiling point of water is dependent on the pressure. The higher the pressure, the higher the boiling point. Or vice versa; a lower pressure provides a lower boiling point. Hence, it ‘s hard to cook food in the mountains at high altitude without the pressure cooker.
Because of the closed lid, the temperature and pressure continue to increase the supply of sufficient heat (energy). That is, of course, undesirable if only because ultimately could crack the pan apart. For this reason, a pressure cooker has a pressure regulator. This is a type of valve that opens when the pressure comes above a particular value. This will cause hot steam and no further pressure rise. The pan continues to boil at the temperature corresponding to the boiling point of water at the appropriate pressure. Because the boiling temperature, the required cooking time will determine there since 1917 a standard pressure of about 103kPa (15 psi) above atmospheric pressure, set in America. The standard pressure in a pressure cooker is, therefore, more than double the normal air pressure at sea level. This allows for a cooking temperature of about 122 ° C. The specified cooking times in most cookbooks and recipes are based on this standard.
Modern pressure cookers still operate on the same fundamental principle. However, they have incorporated some additional safety features, such as an additional overpressure protection, the lid can not be opened if the pan is under pressure and so on. Moreover, they sometimes have two (or more) positions, even though it is not necessary, the small area can be used in, for example, vegetables. Also, don’t have a fresh pressure pot not escape continuous steam. There is often a useful indicator which indicates to whether the stove/burner must be adjusted higher or lower to maintain with minimal energy (cost) operating temperature (and pressure).
Advantages and disadvantages of a pressure cooker
Shorter cooking times (faster finished cooking), of course, is particularly worthwhile for dishes that normally require much time, like a stew with beef. Cooking times are final proof 1/3 of the regular cooking time. A stew usually 3 hours should simmer with the pressure cooker in an hour set! For vegetables that typically shortly cooking is a pressure cooker quickly too much hassle and gives wing to no time savings.
- Significantly lower energy consumption (up to 90%), saving on energy and the environment.
- Healthier and tastier.
- Better retention of color and flavor, vitamins and minerals.
Modern quick buy pans are often equipped with baskets and grids allowing multiple dishes at the same time can, for example, vegetables and potatoes. The disadvantage here is that the smell/taste (partly) can mingle with each other and that it is less useful as there are large differences in cooking time. An advantage of a basket is that, for example, the vegetable is not in the water, but above it, they will make the steamed and still continue to retain more of the vitamins and minerals.
Disadvantages of a pressure cooker, in particular, the purchase price, the weight (rather a thick pan and lid about the pressure), and a greater risk of burns due to the high pressure and temperature. Furthermore, the service life will be shorter than a conventional pan or maintenance is required in the form of, for example, a new sealing ring. However, many manufacturers now offer a ten-year warranty. Another disadvantage is that it is not possible to watch during the cooking as in the pan how it stands, or to further add some ingredients. | physics |
https://www.buzznicked.com/chernobyl-exclusion-zone-photos-34-years-later/ | 2023-03-30T17:37:54 | s3://commoncrawl/crawl-data/CC-MAIN-2023-14/segments/1679296949355.52/warc/CC-MAIN-20230330163823-20230330193823-00273.warc.gz | 0.965512 | 1,049 | CC-MAIN-2023-14 | webtext-fineweb__CC-MAIN-2023-14__0__33539408 | en | 36 years ago the biggest nuclear disaster in the history of the human race occurred due to human error at the Chernobyl Nuclear facility. This meltdown caused the evacuation of more than 50,000 people within the matter of only 3 hours and tens of thousands more within the days to follow. 115,000 people were evacuated by 1986 and another 220,000 people in the subsequent years. An experiment caused a reaction that could not be stopped. An explosion occurred and spread radiation and radioactive material hundreds of miles around the reactor. This has affected the lives of everyone involved with the disaster as well as the generations that came after. Many people are still suffering severe health problems from this catastrophe. These images were taken over 30 years after the incident and you can see that it is still a very contaminated area and will be for tens of thousands of years.
2. The World Health Organization estimates that 30,000 deaths can be attributed to the disaster.
4. Over 7 million people have been exposed to the radiation released.
6. The first person to die in the Chernobyl accident was Valery Khodemchuk, a plant worker who was monitoring the water pumps to the nuclear core.
8. Radioactive dust from the accident reached as far away as the eastern United States spreading cross Eastern and Western Europe.
10. The explosion happened in 1986 and officials say it could take up to 100 years before the plant is completely decommissioned.
12. Nuclear rain from the explosion spread as far as west Ireland.
14. The Chernobyl explosion unleashed at least 400 times more radioactive fallout than the bomb the United States dropped on Hiroshima in 1945
16. It will take over 3,000 years for the neighboring town of Pripyat to be safe for people to inhabit again.
18. Birds in the area have brains that are significantly smaller than the same species living in non-contaminated areas.
20. Trees now grow much slower than their non-contaminated counterparts.
22. Game animals living in the area, including some found as far away as Germany, still show dangerous levels of radiation.
24. After the Chernobyl disaster, one nearby forest, now known as the “Red Forest,” turned a reddish color and died. However, even 15–20 years after the meltdown, the trees have not decayed.
26. Because of the lack of people and development, the wildlife in the area has seen immense growth in numbers.
28. 28 firefighters died within 3 months of being exposed to the Chernobyl disaster. All from radiation sickness.
30. Even though the disaster occurred in the Ukraine, Belarus received an estimated 70% of the contamination.
32. If the steam explosion wasn’t prevented by the 3 men named the “Suicide Squad” all of Europe would be uninhabitable foe hundreds of years.
34. Over 200 tons of radioactive material still remains inside the reactor.
36. The Soviet Union tried their best to hide the situation. The world was alerted because of a radiation detection device in Sweden.
38. Nearly 5 million people living in the area today are still considered contaminated.
40. People in the nearby town weren’t evacuated for 2 days after the incident.
42. Three other reactors on the site ran for 13 years after the disaster.
44. Tourist agencies actually have daily tours that bring you into some parts declared somewhat safe in the abandoned town of Pripyat.
46. Pripyat is highly contaminated and needs over 24,000 years just to reduce half of its intensity!
48. Radiation was so strong that the eyes of firefighter Vladimir Pravik changed from brown to blue.
50. The explosion was so strong that it blew a 1000 ton plate that covered the reactor core clean off.
The disaster has shaped nuclear technology and safety procedures in hopes of preventing any disasters like this from happening again. Its been over 25 years and the problem is still very real. Right now engineers have designed a shell that is going to be built over the reactor to filter out any radiation that would possibly be released into the air. This steel structure has been designed to last 100 years or more. When the disaster happened on April 26, 1986 a team designed a “sarcophagus” that covered the reactor. This was a temporary fix and is falling apart from the radioactivity contained within. We have the power to destroy ourselves and this is just one example of how detrimental human error can be when dealing with such powerful elements. Right now the only people allowed near Chernobyl are government officials, guards and people who are there to assess and evaluate the damages. Scientists estimate that the immediate area near reactor 4 will be unsafe for another 20,000 years. | physics |
https://thebic.co.uk/great-british-inventions-to-inspire-you/ | 2020-09-18T19:06:37 | s3://commoncrawl/crawl-data/CC-MAIN-2020-40/segments/1600400188841.7/warc/CC-MAIN-20200918190514-20200918220514-00705.warc.gz | 0.959513 | 817 | CC-MAIN-2020-40 | webtext-fineweb__CC-MAIN-2020-40__0__232036068 | en | GREAT BRITISH INVENTIONS TO INSPIRE YOU
As an island, it is generally felt that Britain had a head start on Innovation. We designed and developed products out of need and led the Industrial Revolution. It wasn’t difficult therefore for BBC 2 to come up with 50 Great British Inventions for their Genius of Invention season.
I am sure every individual would choose their own special Inventions but here are the top five chosen by our young Work Experience student Sam Thompson:
1. The Electric Telegraph
This was invented by Charles Wheatstone and William Cooke in 1837 and the first fully operational telegraph ran in 1839 from Paddington to West Drayton Railway Stations in London. Morse Code made it efficient and in 1858 the first transatlantic cable was laid and by the end of the century, there were more than 150,000 miles of cable connecting the globe.
2. The Steam Turbine
After the invention of the electrical motor which transforms rotation into electrical power, the next step was to find a device to drive it. Piston engines vibrated too violently and then Charles Parson invented the steam turbine making the gaps between the blades very small so that the steam would accelerate through the turbine and turn it quicker. Three-quarters of the world’s power stations still use steam to operate.
3. Sewage System
There are very few creations that we use every day hardly ever thinking about it but that is exactly what sewers are and the largest and most forward-thinking sewage system in the world was created by Joseph Bazalgette in 1865 in London. The existing, smelly and unhealthy system pumped sewage into the Thames – Bazalgette’s sewer was pumped miles away into the sea. The London sewage system measures 80miles and is still operating today.
4. Passenger Railway
Coming from a very poor background, illiterate until 18, it is remarkable how George Stephenson rose from a night school student whilst working at a colliery to invent not only steam engines that could actually run on tracks but the first locomotive without horsepower and eventually the first regular passenger-carrying railway. This was the Stockton and Darlington and the first intercity railway was between Liverpool and Manchester. Stephenson’s system of train coupling became the European standard and his chosen gauge or distance between the two rails of 4ft 81/2 in (1.435m) became the world’s standard gauge.
A number of people could have invented the telephone but it was Edinburgh born Alexander Graham Bell who patented it first in 1876. The telephone came about thanks to the discovery that a thin metal sheet vibrating in an electromagnetic field produces an electrical waveform that corresponds to the vibration and can be acoustically reproduced. Following a simple call to the room next door, the first long distance call over ten miles was made in Canada a month later. The rest, as they say, is history as the telephone has had numerous evolutions over the years.
New products and services can be very valuable to a business and being first to market is usually a good thing BUT we aren’t all inventors and sometimes we need a helping hand to come up with new ideas.
If you or your team need a helping hand come along to the BIC’s next workshop looking at Innovation and Ideas Generation – we might be able to help you come up with the next generation of products for your business as we can’t afford to stand still!
BIC | Events
Ministers announce new grants for businesses affected by local lockdowns GOV.UK [...]
Culture Recovery Fund saves 135 grassroots music venues with emergency grants GOV.UK [...]
Heritage Emergency Fund grants released in 'record time' to 961 UK organisations Museums + Heritage Advisor [...]
Government's £40 million Green Recovery Challenge Fund opens for applications GOV.UK [...]
Heritage Fund provides £50m in direct relief to UK heritage projects SBC News [...] | physics |
https://brussels.whiterose.ac.uk/sheffield-university-scientist-part-of-nobel-prize-winning-team/ | 2020-09-23T07:30:21 | s3://commoncrawl/crawl-data/CC-MAIN-2020-40/segments/1600400209999.57/warc/CC-MAIN-20200923050545-20200923080545-00424.warc.gz | 0.940569 | 363 | CC-MAIN-2020-40 | webtext-fineweb__CC-MAIN-2020-40__0__119947105 | en | Sheffield University scientist part of Nobel Prize winning team
Dr Ed Daw from the University of Sheffield’s department of Physics and Astronomy is part of the LIGO (Laser Interferometer Gravitational-Wave Observatory) Scientific Collaboration that made the Nobel Prize winning discovery.
The very first observation of Gravitational Waves, which was first theorised by Albert Einstein more than a century ago, was announced in February of 2016 and opens an unprecedented new window onto the cosmos. The discovery has been over forty years in the making and the LIGO Scientific Collaboration consists of over 1000 scientists from all around the world.
Gravitational waves carry information about their dramatic origins and about the nature of gravity that cannot otherwise be obtained. Based on the signals, Dr Daw and the network of LIGO scientists estimate that the black holes, from which the gravitational waves were detected, were about 29 and 36 times the mass of the sun, and collided around 1.3 billion years ago.
Reacting to Nobel Prize announcement Dr Daw, who has been researching gravitational waves with LIGO since 1998, said: “I’m pleased to see this achievement recognised on behalf of the thousands of scientists who work on LIGO, including the University of Sheffield group.
Dr Daw added: “The future of gravitational wave physics is now intimately tied up with the future of astronomy. The field is set to expand rapidly, with more sensitive instruments needed to sense smaller signals and larger scale instruments needed to probe lower frequencies where many of the astronomical signals lie”.
To read more on this story or if you want more information on the University of Sheffield’s department of Physics and Astronomy visit: https://www.sheffield.ac.uk/physics/news | physics |
http://dengfengjinyu.en.made-in-china.com/product/fqCxRBdAXeVr/China-Super-Silicon-Carbide-Heating-Elements.html | 2014-12-20T13:37:57 | s3://commoncrawl/crawl-data/CC-MAIN-2014-52/segments/1418802769888.14/warc/CC-MAIN-20141217075249-00043-ip-10-231-17-201.ec2.internal.warc.gz | 0.847577 | 422 | CC-MAIN-2014-52 | webtext-fineweb__CC-MAIN-2014-52__0__77606503 | en | Super Silicon Carbide Heating Elements
- Model NO.: SC1400
- Non-Metal: Silicon Carbide
- Heating Elements: Heater
- Furnace: Kiln
- Export Markets: Global
- Trademark: JINYU
- Packing: Wooden Box
- Standard: ISO9001: 2000
- Origin: China
- HS Code: 851
- Production Capacity: 50, 000 PCS/Month
Jinyu Silca SiC heating element is a type of non-metal high temperature heating device. These SiC productsare made from fine quality green silicon carbide as its main raw material. The raw material is made first in to a blank, followed by high temperature silication and recrystallization, and becomes high quality stick shaped SiC electric heating devices. Compared with metal electric heating material, this type of non-metal elements is featured of high operation temperature, anti-oxidization, long service life, little deformation, easy installation and maintenance. Because of these advantages, SiC electric heating elements is widely used in various industries that require high temperature electric furnaces and heating devices.
These typical applications include electronics, magnetic materials, powder metallurgy, ceramics, glass, metallurgy and machinery.
We adopt new production process of cold end, so Jinyu Silca heating elements have excellent specific rate of heat zone resistance and cold end resistance, saving energy, long life, avoiding over-temperature of cold ends damaging furnace body.
Products specification: Rod type, U type, W type (Three Phase type), Solid Rod type, Spiral type, 5 piece type (dual hot zone). Sizes are available from Dia 12mm, 14mm, 16mm, 18mm, 20mm, 25mm, 30mm, 31.7mm (1.25inch), 35mm, 38.1mm (1.5 inch), 40mm, 44.4mm (1.75 inch) to 54mm (2.125 inch) for all types. | physics |
https://juliaview.com/2013/08/18/epic-rain/ | 2023-05-31T20:09:24 | s3://commoncrawl/crawl-data/CC-MAIN-2023-23/segments/1685224647409.17/warc/CC-MAIN-20230531182033-20230531212033-00149.warc.gz | 0.976647 | 491 | CC-MAIN-2023-23 | webtext-fineweb__CC-MAIN-2023-23__0__102596670 | en | It finally rained. But it wasn’t your typical pitter patter of rain, no. It was the most amazing rainstorm I have ever seen. When it rains in Africa, it really rains. At least here in Gashora. That old school song by Toto popped in my head about the rains in Africa.The girls and I looked out of our dorm into the darkness watching as the rain came down in heavy sheets, listening to the crashing of water against our tin roof. We chatted and looked out as flashes of lightning lit up the sky and caused our campus to go black due to brief power outages. It was eerie and awesome. I hung out with some of the wonderful girls of my dorm and we talked and laughed about silly things. They talked about how funny it would be if a physicist was proposed to for marriage and she just ended up cutting the diamond in a lab to examine it’s total internal reflection effect. The total internal reflection effect, as they explained to me, is a physics phenomenon that occurs when there is light within an object (such as a diamond) that creates an effect of reflection even though it is undergoing mostly refraction, more or less. (Click this blue text for a better understanding of the TIR effect.) The girls really excel in physics here at our school. To say these girls are bright would be an understatement. I just know they’re going places no matter what they do. Whether they become physicists, doctors or lawyers like many of them want to be, they’ll do great things. But they might not realize the power of a profession in teaching or business or creative career. As long as they remember who they are is what is most important, not just what they do, i think they will be very happy. I’m excited for them.
The rain continued through the night and all sounds were washed away by the loud, white noise of rain hitting the roof as I slept. The next day brought the freshest of fresh scents of recently quenched earth.
One thought on “Epic Rain”
I love this song and I’ve wondered about the rains in Africa. We’ve had some good rains in Montana lately too. It’s so cool that the girls have such interests and curiosity about so many things. I never would have guessed physics as an interest. | physics |
http://www.geothermalprofessionals.com/ | 2013-05-22T14:03:09 | s3://commoncrawl/crawl-data/CC-MAIN-2013-20/segments/1368701806508/warc/CC-MAIN-20130516105646-00050-ip-10-60-113-184.ec2.internal.warc.gz | 0.922416 | 161 | CC-MAIN-2013-20 | webtext-fineweb__CC-MAIN-2013-20__0__183230575 | en | Qualified professionals for all of your geothermal needs.
Geothermal energy is a renewable energy source because the heat is continuously produced inside the earth. The word geothermal comes from the Greek words geo (earth) and therme (heat). Simply put, geothermal energy is heat from within the earth.
We can make use of the stable temperatures near the surface of the earth to heat and cool buildings.
Geothermal Professionals, Ltd is a Chagrin Falls, Ohio based, fully integrated and licensed geothermal system installation company. We make owning a geothermal system easy.
We perform every step of the project: System Design, Drilling, Loop Installation, Service and Maintenance. Stop by our showroom to see one of our units or give us a call to learn more. | physics |
https://www.larrywolf51.com/2021/09/cataclysm.html | 2024-04-24T16:54:22 | s3://commoncrawl/crawl-data/CC-MAIN-2024-18/segments/1712296819668.74/warc/CC-MAIN-20240424143432-20240424173432-00671.warc.gz | 0.907182 | 1,034 | CC-MAIN-2024-18 | webtext-fineweb__CC-MAIN-2024-18__0__140026375 | en | |Harold Eugene Edgerton, Atomic Bomb Explosion Before 1952
Harold Eugene Edgerton
Atomic Bomb Explosion before 1952
About 1952, printed later
Gelatin silver print; edition 23 of 25
This uncanny, amorphous ball represents the initial detonation of a nuclear test blast, arrested for one millionth of a second. In the 1940s Harold Edgerton devised the rapatronic camera (short for rapid action electronic), and the United States Atomic Energy Commission contracted his lab to use it to capture the various stages of atomic explosions. The rapatronic camera employs two polarizing filters and a Faraday cell-a coil that acts as a magnet when it comes in contact with an electric current. The cell, activated by a pulse emitted by the bomb just before it explodes, momentarily changes the polarization of the filters to let light pass through and reach the film inside the camera.
Gift of the Harold and Esther Edgerton Family Foundation, 1996.568
Label text from the exhibition - Art Institute of Chicago: The Human Landscape
J Robert Oppenheimer - We Are Death
Background on the Atomic Bomb Explosion - Code Named Harry
HARRY, Operation UPSHOT-KNOTHOLE. 4:05am May 19 1953, Nevada Test Site, tower detonation at 300', yield 32 kilotons. Photographed by an automatic ultra high-speed camera, Harry's fireball is frozen approximately 0.0001 seconds after detonation, before the blast has engulfed the tower. The surface mottling and irregularity is a result of high-velocity bomb debris "splashing" against the backside of the slightly slower expanding fireball, which glows due to compression heating of the surrounding air. Harry tested a device designed by nuclear miniaturization expert Ted Taylor that resulted in the most efficient low-yield fission detonation ever. "Dirty Harry" was also a radiological disaster, creating the worst fallout contamination of any of the U.S. continental atmospheric nuclear tests. 1000 troops observed the fireball, which lasted an unusually long 17 seconds; the radioactive debris cloud rose to a height of 38,000' and then moved directly over St. George, Utah, 100 miles to the east. Deadly fallout inundated the entire town of 5000 nocent and unsuspecting residents, most of whom would later develop cancer. The Hollywood film The Conqueror, starring John Wayne and Susan Hayward, was shot the following summer in a canyon near St. George; 30 years later, 91 members of the cast of 220 had developed various cancers, and Wayne and Hayward would both die of it. Of the estimated cumulative total of 85,000 person-roentgens of external gamma ray exposure created by all continental tests from 1951 to 1958, Harry is thought to have contributed 30,000 alone. Fallout from three other tests in the Operation Upshot-Knothole series would prove especially deadly as well: Nancy, detonated on March 24, would kill 4390 sheep near Cedar City, Utah; Dixie, detonated on April 6, would cover Boston with radiation, and Simon (see #019), detonated April 25, would douse Albany, New York with unsafe levels of radioactive rain. Shortly after the Operation's conclusion a Utah Congressman demanded that all testing on the continental United States stop; public concerns about the dangers of fallout began to coalesce as a national issue. The Atomic Energy Commission publicly maintained until its dissolution in 1974 that no damage was done from either Harry or Nancy; internal documents declassified thereafter showed this to be a patent lie. Image from an Edgerton, Germeshausen, & Grier Rapatronic camera by U.S. Air Force 1352nd Photographic Group, Lookout Mountain Station.
text from Michael Light - 100 Suns
Notes on Edgerton Atomic Bomb Explosion Photograph
The exposure was made 7 miles from the atomic explosion using a 10-foot lens.
There is a 4x5 copy negative at the Harvard Art Museum
In addition to the Art Institute of Chicago, several other museums have copies of this print (MIT Museum, Smithsonian American Art Museum, Detroit Institute of Arts, Philadelphia Museum of Art, Whitney Museum of American Art, Nelson-Atkins Museum of Art, Minneapolis Institute of Art, National Gallery of Canada). They are gifts of The Harold and Esther Edgerton Family Foundation.
This page includes a diagram of the rapatronic shutter
See also this informational document at the Nevada National Security Site
And this about the "end" of nuclear testing at the United Nations International Day Against Nuclear Tests
Cataclysm - Definition and Etymology
a large-scale and violent event in the natural world.
a sudden violent upheaval, especially in a political or social context.
early 17th century (originally denoting the biblical Flood described in Genesis): from French cataclysme, via Latin from Greek kataklusmos ‘deluge’, from kata- ‘down’ + kluzein ‘to wash’. | physics |
http://rodisbeernuts.tumblr.com/ | 2014-09-18T19:42:53 | s3://commoncrawl/crawl-data/CC-MAIN-2014-41/segments/1410657129229.10/warc/CC-MAIN-20140914011209-00142-ip-10-196-40-205.us-west-1.compute.internal.warc.gz | 0.960674 | 355 | CC-MAIN-2014-41 | webtext-fineweb__CC-MAIN-2014-41__0__126340377 | en | As forecast, heavy rain, thunder and frequent lightning has been moving across the UK.
The video above shows the lightning strikes that have been recorded across the UK and Ireland between 1am and 11.27am on Saturday.
In this time, around 4300 lightning strikes have been recorded, gradually spreading northwards.
The lively weather has been caused by warm, humid air from France and Spain, colliding with cooler air from the Atlantic.
How is lightning detected?
When lightning strikes occur, pulses of electromagnetic energy are created, spreading out in all directions.
These pulses, known as sferics, have a very low frequency (VLF), which is outside the range of what we are able to see and much lower than the frequency of normal radio waves.
These VLF waves are capable of travelling large distances because they are reflected between the surface of the earth and a layer of the upper atmosphere called the ionosphere.
Detection of these very low frequency sferics is carried out by ATDnet – a Met Office network of 11 sensors around the world that works around the clock, collecting information.
When a lightning strike occurs, each sensor will record the sferic at a slightly different time as the distance between each sensor and the point at which the lightning strike originated will vary.
The network of sensors, connected to a central computer at Met Office HQ, then cross-references the time each lightning strike took to be detected by each sensor, and is then able to triangulate the point at which it took place – a process called Arrival Time Difference (ATD).
Once a lightning strike has been detected, the information can be plotted on a map to show when and where they have taken place. | physics |
https://festival16.summerhall.co.uk/exhibition/haroon-mirza/index.html | 2024-02-24T02:09:33 | s3://commoncrawl/crawl-data/CC-MAIN-2024-10/segments/1707947474482.98/warc/CC-MAIN-20240224012912-20240224042912-00233.warc.gz | 0.959361 | 436 | CC-MAIN-2024-10 | webtext-fineweb__CC-MAIN-2024-10__0__22886553 | en | Adam, Eve, others and a UFO
Haroon Mirza has won international acclaim for installations that test the interplay and friction between sound and light waves and electric current. He devises kinetic sculptures, performances and immersive installations. An advocate of interference (in the sense of electro-acoustic or radio disruption), he creates situations that purposefully cross wires. He describes his role as a composer, manipulating electricity, a live, invisible and volatile phenomenon, to make it dance to a different tune and calling on instruments as varied as household electronics, vinyl and turntables, LEDs, furniture, video footage and existing artworks to behave differently. Processes are left exposed and sounds occupy space in an unruly way, testing codes of conduct and charging the atmosphere. Mirza asks us to reconsider the perceptual distinctions between noise, sound and music, and draws into question the categorisation of cultural forms.
This installation Adam, Eve, others and a UFO was first shown in an exhibition by the artist at Lisson Gallery in 2013. A UFO-circuit is equipped with eight LEDs and placed in the centre of the room. From there, cables run to eight, circularly arranged, yet non-identical speakers (one branded ADAM and another EVE). The electric current that causes the short flashing, brightening or dimming of the LEDs creates different sounds, audible through speakers, which are controlled by a computer programmed by Mirza to form a minimalist electronic piece of music. The dark grey foam on the walls, which generates a recording studio atmosphere, and the carpet are used to reduce reverberations and keep the sound in the centre of the room.
Haroon Mirza was born in London in 1977, where he lives and works. His work was included in the 7th Shenzhen Sculpture Biennale, China (2012) and the 54th Venice Biennale, Italy (2011), where he was awarded the Silver Lion. He was awarded the Northern Art Prize in 2011, the DAIWA Foundation Art Prize in 2012, the Zurich Art Prize in 2013, the Nam June Paik Art Center Prize in 2014 and the Calder Art Prize in 2015. | physics |
http://ehplct.blogspot.com/2010/04/happy-anniversary-hubble.html | 2018-07-23T10:00:02 | s3://commoncrawl/crawl-data/CC-MAIN-2018-30/segments/1531676596204.93/warc/CC-MAIN-20180723090751-20180723110751-00325.warc.gz | 0.908686 | 202 | CC-MAIN-2018-30 | webtext-fineweb__CC-MAIN-2018-30__0__184576036 | en | Today marks the 20th anniversary of the Hubble Space Telescope whose operation has granted us a greater view of our own solar system and distant galaxies formed shortly after the birth of the Universe. Hubble has helped prove and advance different theories for astronomy and physics and has outlived its original projected life span, allowing us to glimpse and understand our place in the cosmos and the life and structure of the Universe. If you would like to learn more about this amazing telescope and see some of the images that it has provided, you can do so through books and websites.
The Universe in a Mirror : the Saga of the Hubble Telescope and the Visionaries Who Built It by Robert Zimmerman
A Journey Through Time : Exploring the Universe with the Hubble Space Telescope by Jay Barbree and Martin Caidin ; foreword by John H. Glenn, Jr.
Hubble : the Mirror on the Universe by Robin Kerrod
Close Encounters : Exploring the Universe with the Hubble Space Telescope by Elaine Scott
NASA's Hubble Site | physics |
https://etradefactory.com/stunning-image-of-supernova-remnant-gives-clues-about-stars-death/ | 2024-04-24T21:58:15 | s3://commoncrawl/crawl-data/CC-MAIN-2024-18/segments/1712296819971.86/warc/CC-MAIN-20240424205851-20240424235851-00083.warc.gz | 0.931815 | 507 | CC-MAIN-2024-18 | webtext-fineweb__CC-MAIN-2024-18__0__201349734 | en | Astronomers finding out the stays of a supernova captured utilizing NASA telescopes have discovered clues that may assist decide the timeline of the star’s demise. Called SNR 0519-69.0, the supernova remnant is the particles from an explosion of a white dwarf star.
According to NASA’s Chandra Ray Observatory, the star underwent a thermonuclear explosion after reaching important mass. Star normally do that by pulling in matter from a companion star or merging with one other dwarf star. This kind of supernova known as a Type Ia, and scientists use them for a variety of scientific research, from finding out thermonuclear explosions to measuring the gap to galaxies which can be billions of light-years away.
SNR 0519-69.0, or SNR 0519 in brief, is situated within the Large Magellanic Cloud, which is a small galaxy about 160,000 mild years away from our planet. X-ray knowledge from NASA’s Chandra X-ray Observatory and optical knowledge from NASA’s Hubble Space Telescope was used to create this composite image.
Low, medium and excessive vitality X-rays from the supernova remnant are depicted in inexperienced, blue and purple respectively with these colors overlapping in some areas to look white. The perimeter across the remnant in crimson and the celebrities across the remnant in white are from the optical knowledge.
Scientists used knowledge from Chandra, Hubble and NASA’s retired Spitzer Space telescope to “rewind” the stellar evolution and explosion that resulted in SNR 0519. They decided how way back the star exploded and realized about its atmosphere. Their analysis is published in The Astrophysical Journal.
They in contrast Hubble pictures of SNR 0519 from 2010, 2011 and 2020 to measure the speeds of the fabric within the blast wave from the explosions. According to their estimates, it ranges from about 6 million to 9 million kilometres per hour. If the pace was nearer to the higher finish of that estimate, the scientists decided that the sunshine from the explosion would have reached Earth about 670 years in the past.
But it’s seemingly that the fabric has slowed down for the reason that star’s explosion and that it occurred extra just lately 670 years in the past. The researchers discovered that the areas that the brightest areas in X-ray pictures are the place the slowest-moving materials is situated. They additionally discovered that no X-ray emission is related to the fastest-moving materials. | physics |
https://datamation.in/product/benq-lw820st-laser-hd-high-brightness-short-throw-projector/ | 2023-06-08T07:48:56 | s3://commoncrawl/crawl-data/CC-MAIN-2023-23/segments/1685224654606.93/warc/CC-MAIN-20230608071820-20230608101820-00289.warc.gz | 0.869181 | 1,577 | CC-MAIN-2023-23 | webtext-fineweb__CC-MAIN-2023-23__0__150609260 | en | BenQ LW820ST Laser Hd High Brightness short Throw Projector!
The LW820ST Is designed around a long lasting laser light source which avoids maintenance and down time associated with replacing lamps and makes it the perfect choice for a heavy use environment. The LW820ST is short throw which makes it easier to get a large image size in a smaller meeting room where you do not want the unit to me several metres away possibly blinding the presenter or having them cast a shadow on the projection. With a detailed HD resolution and a 3600 lumen brightness it is perfect for a meeting room or classroom.
BlueCore Laser Projector with Short Throw, WXGA | LW820ST
Uninterrupted Learning Through Long-Lasting Projection.
The World’s No.1 DLP brand BenQ leads the way with futureproof interactive projectors, featuring innovative BlueCoreTM laser technology and superior dustproofing design for superb picture quality and maintenance-free operation. Maximizing education investment and collaborative learning with short throw projection, BenQ LX820ST / LW820ST utilize the unparalleled qualities of a laser light source to achieve optimized performance, long-lasting reliability, energy efficiency and environmentally friendly choice for the leading school.
Precision-Aligned High-Output Laser Source
Zero-deviation alignment of BlueCore laser diodes boosts luminous flux into the light tunnel, improving light efficacy to 3,600 lumens.
Secondary Yellow-Infused Color Wheel
Dual synchronized BlueCore color wheels utilize an additive yellow segment, stimulating precise RGBY spectra for optimal chromatic performance.
Hermetically Sealed DLP Chip
Comprising over two million micromirrors that reflect pure light through the color wheel, the DLP chip is hermetically sealed to resist heat for over 100,000 hours without degradation.
Superior Dustproofing Design to Prolong Projector Lifespan
BenQ LW820ST is designed with DustGuardTM technology including sealed laser modules to protect the laser bank. This lock-and-key design hermetically seals the laser engine from dust* to prolong projector lifespan.
Sealed Engine for Laser Light Source
With a fully enclosed laser light source and an innovative sealed engine design powered by BenQ Dust GuardTM technology, BlueCore education projectors guarantee 20,000 hours of maintenance-free operation to prevent extra expenses on lamp replacement and maintenance. The laser light source resists brightness decay, making BenQ laser education projectors highly stable while ensuring high brightness performance through years of usage.
Brilliant Display of Lecture Content
LW820ST’s powerful BlueCoreTM laser projection utilizes a dual color wheel system to produce outstanding color performance by increasing color ratios and purity of RGBY colors, greatly enhancing color saturation and brilliancy at the same lumen output of lamp-based projectors to deliver superior viewing experiences.
Long Lasting High Brightness
LW820ST produces 3,600 ANSI lumens and superior brightness efficiency, at the same level as IFPs for clear, sharp images and text even in large, bright classrooms with lights kept on during lessons. LW820ST’s Custom Brightness function also allows manual light output adjustments in 1% increments to precisely control projection brightness to fit ambient lighting and conserve energy, as well as providing perfect edge blending for multiple projector applications.
Laser-Enabled Ultra-High Contrast
LW820ST laser projectors create strikingly clear images with stratospherically high native contrast ratio of 100,000:1 for true deep blacks, vividly rich colors, and fine subtle details. LW820ST also features spontaneous response, requiring no wait to turn on or resume from blanking in true black for flexible performance capability.
BenQ BlueCoreTM education projectors can be turned on and off instantly to significantly reduce setup time compared to other lamp-based projectors.
|20,000 Hour Long-Lasting Performance
With a fully sealed laser light source and an innovative sealed laser engine design, BenQ BlueCoreTM laser education projectors guarantee 20,000 hours of maintenance-free operation, preventing extra expenses on lamp replacement and maintenance. The laser light source resists color and brightness decay over time, offering significantly more reliable performance after a period of operation.
Expanding Classroom Possibilities
Ultra-short throw projectors can be mounted inches the wall directly above the screen, eliminating distracting shadows and glare for students and teachers to engage and collaborate freely in front of the board.
BenQ education projectors offer a range of resolutions and projected image sizes to meet diverse classroom needs. Featuring crisp image quality up to 100 inches, our ultra-short throw education projectors deliver increased classroom versatility at reduced costs.
Unobstructed Instruction Without Space Constraints
Offering a big screen in short distances with a 0.49 short-throw ratio, LW820ST eliminates distracting shadows and glare for students and teachers to engage and collaborate freely in front of the board.
BenQ education projectors offer a range of resolutions and projected image sizes to meet diverse classroom needs. Featuring crisp image quality up to 100 inches, BlueCore short throw education projectors deliver increased classroom versatility at reduced costs.
Multi-Touch with Pens and Multi-Screen Drawing
PointWrite™ projectors offer multi-user capability, and two PointWrite™ projectors can be used to double the projection surface. With QWrite* Whiteboard Mode, teachers can run different applications or display, view, and annotate across two monitors.
|Advanced Interactive Module Compatible
For engaging and intuitive lessons, teachers and students can bring their own smart devices and computers to stream documents, images, and even Full HD videos to LW820ST projectors, facilitating the free exchange of ideas and collaborative teamwork.
Facilitating Smart, Efficient Projector Maintenance
Control System Compatibility
LW820ST is widely compatible with leading projector control systems including Crestron, AMX, PJ Link, and Extron* IP Link for network control via LAN, making it simple to integrate into educational network infrastructures. LW820ST also supports RS-232 for reliable long-distance Installation up to 15 meters when there is no LAN infrastructure.
Centralized Control with BenQ MDA Software
BenQ Multiple Display Administrator (MDA) software enables powerful centralized monitoring, control, and power scheduling across the school’s projector network from a single computer, offering full access and control over every projector directly.
>>Link to software page
Centralized Upgrade Tool for Multiple Projector Maintenance
Administrators can centrally upgrade firmware on multiple BenQ projectors that are on the same local network via LAN (up to 253 projectors,) deploying the latest updates to all devices at once. This new application can upgrade firmware with a friendlier interface.
Clear Images without Distortion
Digital Shrink is used for fine tuning the screen size via OSD menu when the image is not precisely aligned on the desired frame.
With industry-leading high contrast, BenQ education projectors utilize advanced DLP-optimized optical lens systems to provide precise readability and crisp resolution for every single sub-pixel.
Be the first to review “BenQ LW820ST Laser Hd High Brightness short Throw Projector” | physics |
https://neuvoo.ru/view/?id=96895bb3814c | 2021-04-18T23:37:18 | s3://commoncrawl/crawl-data/CC-MAIN-2021-17/segments/1618038862159.64/warc/CC-MAIN-20210418224306-20210419014306-00139.warc.gz | 0.88195 | 297 | CC-MAIN-2021-17 | webtext-fineweb__CC-MAIN-2021-17__0__103730873 | en | This position is charged with improving the reservoir simulator's geo-mechanical modeling. At this time, the simulator uses either compaction tables or an explicitly coupled geo-mechanical simulation (third party) to simulate the impact of geo-mechanical rock distortions brought on by stress (pressure) changes during reservoir production or injection.
The project will begin with a complete analysis of our options going forward. At one extreme this could include recommendation and the building of a full finite element geo-mechanical simulator.
At the more simple end of the spectrum identification of a better explicitly coupled 3rd party solution. The candidate will develop models where the interaction between fluid and rock deformation is studied.
The development will include mathematical models, numerical discretization of multi-phase fluid mass and rock deformation equations, and numerically efficient Fortran code implementation in the existing simulator.
Coding experience. A Ph.D. in Engineering (or exceptionally qualified M.S. candidate) or degrees in math or other sciences with appropriate background.
Strong communication skills in English are required.
Nice to have
Coding experience with Fortran 90
Previous experience with a finite element geo-mechanics simulator and coupled geo-mechanical modeling for fractured formations is a plus.
A Ph.D. in Engineering (or exceptionally qualified M.S. candidate) with background in petroleum reservoir highly desire.
Preferred to have parallel MPI experience. | physics |
http://ailingplanet.com/accessing-the-tiny-magnet-within-the-core-of-a-single-atom/ | 2018-11-19T15:49:28 | s3://commoncrawl/crawl-data/CC-MAIN-2018-47/segments/1542039745800.94/warc/CC-MAIN-20181119150816-20181119172816-00325.warc.gz | 0.944835 | 332 | CC-MAIN-2018-47 | webtext-fineweb__CC-MAIN-2018-47__0__187048013 | en | This was significant because ordinarily the nuclear spin, a process that describes the magnetism of the atom’s core, can only be detected in very large numbers. Hyperfine refers to the coupling between a single atom’s nuclear spin and its electron counterpart, causing small shifts and splittings in the energy levels of atoms, molecules, and ions.
This was achieved through the use of a Scanning Tunneling Microscope, which is an instrument for imaging surfaces at the atomic level. The microscope is based on the concept of quantum tunneling, where a particle passes through a potential barrier that it classically cannot surmount.
With the microscope function, when a conducting tip is brought very near to the surface to be examined, a bias (voltage difference) applied between the two can allow electrons to tunnel through the vacuum between them. The resulting tunneling current is a function of tip position, applied voltage, and the local density of states. This can be visualized in image form.
In terms of the research implications, the science team aims to use this sensitivity of the hyperfine interaction within the chemical environment as a quantum sensor.
Speaking with Phys.org about the research, lead scientist Professor Andreas Heinrich said: “I am very excited about these results. It is certainly a milestone in our field and has very promising implications for future research. By addressing individual nuclear spins we can gain deeper knowledge about the structure of matter and open new fields of basic research.”
The research has been published in the journal Science. The associated paper is titled “Hyperfine interaction of individual atoms on a surface.” | physics |
http://www.mikewilsonphoto.co.uk/solar-eclipse-2015/ | 2018-02-23T02:10:46 | s3://commoncrawl/crawl-data/CC-MAIN-2018-09/segments/1518891814311.76/warc/CC-MAIN-20180223015726-20180223035726-00050.warc.gz | 0.936879 | 306 | CC-MAIN-2018-09 | webtext-fineweb__CC-MAIN-2018-09__0__150415630 | en | I’d known about the partial solar eclipse a few weeks prior to the event so had planned where I wanted to shoot the event from using the PhotoPills app on my iPhone. Based on the information from the app, I knew if I positioned myself at Bude lock gates and faced inland, I could capture the partial eclipse occurring over Bude Canal.
Luckily enough, the South West was one of the best places in the UK to view the solar eclipse with almost perfect conditions over most of the region, with only a slight haze which made the sky a little ‘mushy’.
I set up my camera on a stable tripod and took a couple of exposures for the foreground. I then used a Big Stopper (10 stop filter) from Lee Filters to allow the camera to expose for the bright sun and set the interval timer to take a shot every 2 minutes, starting 5 mins before the moon first aligned with the sun and finishing approximately 2 hours later, 5 minutes after the moon passed the suns alignment with the earth.
In post-processing, I aligned the exposures in a stack to show the different phases of the solar eclipse. I decided to only use every third sun exposure so the final composite image shows an exposure of the sun taken every 6 minutes.
The next partial solar eclipse in the UK won’t occur until 2026, so in the meantime I hope this image gives you an illustration of what occurred during the 2015 solar eclipse in Bude, Cornwall. | physics |
http://menasassociates.blogspot.com/2010/10/iran-loads-first-fuel-batch-into.html | 2018-07-15T19:23:19 | s3://commoncrawl/crawl-data/CC-MAIN-2018-30/segments/1531676588961.14/warc/CC-MAIN-20180715183800-20180715203800-00047.warc.gz | 0.949114 | 202 | CC-MAIN-2018-30 | webtext-fineweb__CC-MAIN-2018-30__0__236257371 | en | Tuesday, 26 October 2010
Iran loads first fuel batch into Bushehr plant
Iran has begun the process of loading fuel into its first nuclear power plant. The Bushehr plant is expected to be fully operational and producing electricity by 2011. Russia will operate the plant, located in southern Iran, supplying fuel and clearing way the nuclear waste.
Iran has been subject to four rounds of UN sanctions due to lack of transparency regarding its nuclear programme, but experts say that as long as Russia operates the Bushehr plant, under the strict supervision of the International Atomic Energy Agency (IAEA), there should be no suspect propagation.
The uranium fuel, to be produced by the Bushehr plant, will be below the enrichment level needed for a nuclear weapon, which must be enriched by more than 90 per cent, the fuel at Bushehr will only be enriched by 3.5 per cent.
Source: BBC News
For more news and expert analysis about Iran, please see Iran Strategic Focus. | physics |
https://www.bluwhaletile.com/flying-fish-strategy-8-ways-to-make-a-swimming-pool-fast.html | 2024-04-14T04:59:18 | s3://commoncrawl/crawl-data/CC-MAIN-2024-18/segments/1712296816864.66/warc/CC-MAIN-20240414033458-20240414063458-00613.warc.gz | 0.941288 | 1,138 | CC-MAIN-2024-18 | webtext-fineweb__CC-MAIN-2024-18__0__93126330 | en | Only those who love swimming will know and realize the feeling of a fast-swimming pool. Something about the special feel just like that you have the ability of a great swimmer. We’ve shared more inspirations and projects of home or hotel swimming pool before, but we rarely talk about the competition swimming pool. Why standard pool will improve the speed of the swimmer? Today, Bluwhale Tile will talk about the reason and read on for more knowledge:
What Elements Will Determine The Speed Of Pool?
1.Standard Pool Size
In all types of swimming pools, those that are true Olympic swimming pool size is the largest, which not only can hold hundreds of thousands of liters of water, but their standard size measurements exceed all residential swimming pools, no matter how big the may seem. There’re two distances for standard racing pools, short course and a long one. The standard short pool is 25 meters long and has six to ten pool lanes. For Olympic pool is 50 meters and with eight to ten pool lane lines.
pic from website
Water waves can also be prevented by the depth of a swimming pool. Besides, the overflow of redundant pool water being the cause, waves are also generated simply by the act of swimmer. Due to the movement of pool water, having lots of waves is bound to happen. Therefore, the best way to decrease the number of waves created and reduce the chance that the waves affect a swimmer’s grade is through the pool depth. While someone who swims in shallow water, waves will bounce off of the pool bottom of the pool and splash the swimmer. So if increasing the depth of a pool, the waves will have more space to travel and fade rather than absolutely impacting the swimmer. The standard competition depth is recommended 3 meters that makes sense!
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3.Advanced Pool Lane
Pool lane also plays an important role in making a fast speed, just similar to the pool depth. But first, lane width is a balance between offering enough space for swimmers to have space to increase their speed and also making sure they haven’t too much space. By the way, pool lane not only provides the appropriate space for every swimmer but reduce the waves which will be bouncing off the pool interior walls and hitting the swimmers. For more high quality and reasonable price pool lane visit here:
Featured Product: Maple Shape Pool Lane LL001G
4.High-Quality Pool Grating
In addition, professional pool drain systems can make the overflow water fall into the pool grating at the pool’s edges rather than creating more waves. These efficient drain systems consist of many pool grates that can drain any excess pool water without overflowing. Therefore, less excess water equals less annoying waves. Not only that, but anti-slip design pool drain grating will also protect swimmers from slipping. If you’re going to having a project of building a standard pool, our new design PVC pool grating might suit you:
Featured Product: PPS Pool Grating GR901G-IT1
5.Suitable Pool Temperature
Pool water temperature has a direct influence on the swimmer, especially competitive swimmers. The perfect water temperature can bring wonderful performance. For cold pool water, cool temperature is not only shocking and physical maladjustment from the initial immersion, but swimmer will feel more and more uncomfortable while they’re swimming and the final result will make them disappointed. On the contrary, those who have a competition in a hot pool will feel more tired because the higher temperature can not remove the redundant heat from their body and make them expending more energy. Therefore, the standard pool must set a suitable temperature, which is 26 degrees centigrade plus or minus 1 degree.
Featured Product: 48x48mm Blends Blue Pool Tile BCK001
6.Anti Slip Starting Blocks
The helpful starting block will allow swimmers to shift their weight to shoulders and hands, rather than their body and feet, which will make the swimmers getting more momentum as fast as possible can increase the record of the swimmers.
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7.Safety Pool Ladders
Swimming pool ladders are always overlooked. Pool ladders and pool steps are a functional and essential part of the standard swimming pool, which can also be a visual focal point. Setting an anti-slip and durable 304 stainless steel pool ladder can make swimmers getting in and out of the pool easier and safer. With SS304 handrail design, our new arrival pool ladder adds security into the competition pools.
Featured Product: Pool Ladder 304 Stainless Steel PL901G
8.Standard FINA Pool Tiles
When it comes to pool tiles, we’ve talked about a lot from the previous blog. Standard pool tiles are different for leisure home or hotel pool. As for the leisure pool, we can choose colorful pool tiles like vibrant green ice-crackle pool tiles, unique shape glass mosaic pool tiles or etc. But for the competition pool, the materials of tiles are strictly required. For more standard FINA pool tiles knowledge, visit our blog:
Featured Product: Anti-slip standard FINA swimming pool tiles
For more professional assistance with your future pool design, count on Bluwhale Tile Team. Our pool designers and skilled colleague will provide some suggestions for your project. And if you’re interested in our products from pool tiles to pool accessories, samples are available here! Let’s contact us for more ideas! | physics |
https://communications.tufts.edu/blog/news/2014/03/31/fantini-sergio-ph-d/ | 2023-12-08T16:46:15 | s3://commoncrawl/crawl-data/CC-MAIN-2023-50/segments/1700679100762.64/warc/CC-MAIN-20231208144732-20231208174732-00414.warc.gz | 0.92829 | 134 | CC-MAIN-2023-50 | webtext-fineweb__CC-MAIN-2023-50__0__4313893 | en | Sergio Fantini, Ph.D., is a professor in the Department of Biomedical Engineering at Tufts School of Engineering. Dr. Fantini’s research interests are in the area of biomedical optics, specifically in diffuse near-infrared spectroscopy and imaging of biological tissues. His research laboratory has ongoing projects aimed at non-invasive functional imaging of the brain, the study of cerebral and skeletal muscle hemodynamics, and the development of novel instrumentation for optical mammography.
Professor Fantini can speak about:
- Non-invasive technologies to monitor tissue, including brain and breast tissue
- Real-time monitoring of biophysical signals | physics |
https://journal.librarianofalexandria.com/a-brief-moment-of-neal-stephenson | 2020-02-17T19:59:56 | s3://commoncrawl/crawl-data/CC-MAIN-2020-10/segments/1581875143079.30/warc/CC-MAIN-20200217175826-20200217205826-00269.warc.gz | 0.984583 | 288 | CC-MAIN-2020-10 | webtext-fineweb__CC-MAIN-2020-10__0__180254568 | en | A Brief Moment of Neal Stephenson
Isaac [Newton], though better equipped than Daniel or any other man alive to understand Relativity, showed no interest in his pie—-as if being in a state of movement with respect to the planet Earth rendered it somehow Not a Pie. But as far as Daniel was concerned, a pie in a moving frame of reference was no less a pie than one that was sitting still: position and velocity, to him, might be perfectly interesting physical properties, but they had no bearing on, no relationship to those properties that were essential to pie-ness. All that mattered to Daniel were relationships between his, Daniel's, physical state and that of the pie. If Daniel and Pie were close together both in position and velocity, then pie-eating became a practical, and tempting, possibility. If Pie were far asunder from Daniel or moving at a large relative velocity—-e.g., being hurled at his face—-then its pie-ness was somehow impaired, at least from the Daniel frame of reference. For the time being, however, these were purely Scholastic hypotheticals. Pie was on his lap and very much a pie, no matter what Isaac might think of it.
—-Neal Stephenson, “The Baroque Cycle”, Vol. 3: “The System of The World”, Book 7: “Currency”, p. 457 | physics |
https://www.muser.press/2024/01/25/new-research-uncovers-varied-impact-of-global-warming-on-typhoons/ | 2024-02-28T04:53:25 | s3://commoncrawl/crawl-data/CC-MAIN-2024-10/segments/1707947474697.2/warc/CC-MAIN-20240228044414-20240228074414-00093.warc.gz | 0.901776 | 543 | CC-MAIN-2024-10 | webtext-fineweb__CC-MAIN-2024-10__0__61735993 | en | Published in Geophysical Research Letters, a study by Nagoya University reveals the surprising effects of global warming on typhoons, suggesting a new method for projecting storm strength.
Tropical cyclones, known for their destructive power, are under the influence of global warming in intricate ways, according to a recent study by researchers from Nagoya University in Japan. The findings, published in Geophysical Research Letters, emphasize the differential impact of rising sea surface temperatures (SST) on typhoons, with larger, slower-moving storms proving more resilient compared to compact, fast-moving counterparts.
As global temperatures continue to rise, the threat of typhoons becomes more pronounced, making it crucial to understand the changes in ocean response to mitigate potential damages. The study led by Sachie Kanada and Hidenori Aiki delves into the relationship between the atmosphere and the ocean, a critical factor influencing weather patterns, ocean circulation, and climate variability.
The research highlights the linkage between typhoon intensity and SST. Traditionally, the size of a typhoon correlates inversely with its intensity, with larger storms experiencing lower SST, limiting their strength. However, under global warming conditions, higher SST levels could prolong the lifespan of typhoons.
Lead researcher Sachie Kanada warns, “The rise in sea temperatures is concerning because a typical compact, fast-moving storm, like Typhoon Faxai in 2019, caused severe damage to eastern Japan. Our findings show the intensity of such typhoons can strengthen under global warming conditions.”
To understand this phenomenon, researchers utilized the CReSS-NHOES model, a state-of-the-art atmosphere-ocean simulator. Examining four powerful typhoons from recent years—Trami (2018), Faxai (2019), Hagibis (2019), and Haishen (2020)—the team evaluated the impact of atmosphere-ocean coupling under various climate scenarios.
Surprisingly, the study found significant variation in how typhoons respond to a 1°C rise in SST. The researchers introduced a parameter called nondimensional storm speed (S0), creating a new model to distinguish between potentially destructive storms likely to strengthen under global warming and those resilient to its effects.
Sachie Kanada emphasizes the significance of the study, stating, “This research, using a high-resolution coupled regional atmosphere-ocean model, can reproduce the intensity and structure of strong typhoons and the response of the ocean with high accuracy.” The findings offer a more nuanced understanding of the complex relationship between typhoons and global warming, providing a foundation for improved intensity projections and more accurate forecasting in the future. | physics |
https://phoenixcnc.in/cnc-water-jet/ | 2023-02-04T18:33:23 | s3://commoncrawl/crawl-data/CC-MAIN-2023-06/segments/1674764500151.93/warc/CC-MAIN-20230204173912-20230204203912-00518.warc.gz | 0.907176 | 1,205 | CC-MAIN-2023-06 | webtext-fineweb__CC-MAIN-2023-06__0__188445122 | en | CNC WaterJet (3 Axis / 4 Axis / 5 Axis)
Machine Prize : 45,00,000.00
Other Names Of Machine: Abrasive Water Jet Cutting Machine, High Pressure Water Jet Cutting Machine, Water Jet Cutting Machine, KMT Water Jet Cutting Machine, CNC Marble Cutting Machine.
We, Phoenix CNC are a renowned Manufacturer and supplier of high grade High Pressure Water Jet Cutting Machine. This range of industrial tool is very effective for cutting designs on material, such as, ceramic tiles, granite, steel, marble, glass, wood, etc. The Aqua-Bayonet and Aqua-Impale Water Jet Cutting Machine offered by us uses high-pressure water jet or an inter-mixture of water and other rough matter to cut through hard material. These are manufactured using quality inputs and thoroughly tested by our quality testers to ensure high precision cutting, and longer functional life.
Take tap water, pressurize it to 60,000 psi (4,000 bar) / 90,000 psi (6200 bar) then force it through a very small hole, or orifice. This creates a tremendous amount of energy concentrated in a thin beam of water, travelling at close to the speed of sound. The result is an extremely powerful and a precise ‘Pure Water’ cutting tool.
An ‘Abrasive’ water system employs the same methods as ‘Pure Water’ however; the addition of an abrasive garnet mixed into the stream increases the cutting forces significantly. When the high-velocity water exits the orifice it creates a vacuum within the mixing chamber. The vacuum pulls abrasive from the abrasive line into the chamber where it is mixed with the water jet stream. The resulting mixture is then realigned in a focusing tube before exiting the cutting head nozzle. At this point the accelerated abrasive particles are now travelling at speeds fast enough to cut through the hardest of materials, all this is achieved by a water jet that is little more than 0.8mm in diameter.
What can we cut? With over 8 years of experience we have successfully profile cut a vast range of materials from low density foams to wear resistant steels.
Metals – Aluminum, Brass, Bronze, Copper, Lead, Mild Steel, Nickel Alloys, Stainless Steel, Titanium.
Non Metals – Carbon Fiber, Ceramics, Glass, Granite, Laminates, Plastics, PTFE, Teflon, Wood.
Soft Materials – Cork, Foams, Foam Rubbers, Graphite, Neoprene Rubber, synthetic material.
WATERJET CUTTING MACHINE
Advantage of Water Jet Cutting The versatility and flexibility of water jet profile cutting as a tool has seen its popularity grow rapidly since its introduction in the mid 1990’s. Some key advantages are:-
No heat affected zone (HAZ) – One of the biggest advantages is water jet’s inherent cold cutting quality. This allows materials to be cut that would be burned, melted or cracked by other cutting methods. It also guarantees that no structural change or metallurgical deformation is placed onto the materials being processed.
Environmentally friendly – The process is clean and does not create dust, fumes or hazardous gases. Cutting oils or coolants are not required.
Narrow kerf – The amount of material removed by the water jet stream is typically about 0.5-1.0 mm wide, meaning that very little material is removed. When you are working with expensive material (such as titanium) or hazardous material (such as lead), water jets small kerf, or cut width optimizes material use, increasing cost effectiveness.
Besides the 3 basic axis, there are other 2 axis, one of them is for rotation, another is angle axis witch is manual without participating in the linkage, so we just call it 4 axis water jet cutting machine.
The tilt angle of 4 axis machine is much smaller than 5 axis machine, the angle is 5 degrees. But it is enough to solve the problem of the cutting slope of water jet. During the cutting process, it can do angle compensation to confirm the incision completely vertical. The cutting accuracy is 0.1mm, can totally meet the requirements of a variety cutting. This equipment has achieved good results in a number of cutting areas, mainly in significant decline of the processing costs and greatly improve of the processing efficiency.
This machine is very useful and turn-on key for marble and granite cutting industry.
The 5 axis water jet cutting machine equips with the A axis (jet swing axis) and C axis (rotating axis) based on the original 3 axis water jet cutter. These two axes can make the cutting head swinging at any angle during the cutting process, and this machine can calculate the real-time cutting trajectory by using the preset angle model of numerical control system, after that the calculation result will be corrected according to the material properties and thickness of the cutting work piece. With 5 axis control system and 3D programming software, our water jet cutting machine can achieve true three-dimensional dynamic cutting. This machine can cut the product cross section without inclination, and cut bevel at any angle, as well as cut the work piece vertically, especially cut cone, curved impeller, gear, etc.
This 5 axis waterjet cutter can cut any angle within +60°, it solves the traditional problem of water cutting inclination, and achieves 2D/3D cutting easily. The line cutting accuracy is +0.1mm, angle cutting accuracy is +0.1°. Our machine is applied to cut bevel surface, straight surface, conical surface, circular surface, rotating surface, groove, chamfer, and arbitrary surface. It can meet the high precision machining demands of mechanical manufacturing, rail transportation, automotive manufacturing, and composite materials processing. | physics |
http://igus.com/wpck/default.aspx?Pagename=tested_FOC&CL=US-en | 2013-05-26T05:31:08 | s3://commoncrawl/crawl-data/CC-MAIN-2013-20/segments/1368706631378/warc/CC-MAIN-20130516121711-00092-ip-10-60-113-184.ec2.internal.warc.gz | 0.92704 | 561 | CC-MAIN-2013-20 | webtext-fineweb__CC-MAIN-2013-20__0__69938848 | en | For safely transmitting large amounts of data via bus systems at high speeds over long distances, the Chainflex® CFLG.G fiber-optic cable has already become a standard – for example, in crane applications. This is due to its insensitivity to electro-magnetic loads and resistance to potentially problematic environmental factors.
What happens with cables on cranes in extremely cold climates? Is the normal maximum cable length (a few thousand feet) reduced through increased dampening at low temperatures? Does the cable break in extreme applications, for example at -40° F? Sensitive glass fibers are conducted in a gel-filled hollow space. How does the gel behave in highly dynamic conditions? What happens in restarts after long downtimes?
As no statements on this topic could be found in any relevant technical journals - and as little was known about the thermal features of the gel - igus®, as part of its company philosophy, undertook its own tests to determine reliable specifications for cable applications in cable carriers.
For this task, the igus® test laboratory was equipped with a freezer that can generate constant temperatures of -40° F and a test facility installed inside for long travels up to 23 ft, speeds up to 5.3 ft/s, and accelerations up to 19.7 ft/s2.
The igus® gradient fiberglass cable, CFLG.6G, was tested in this set-up. The cable was tested with a length of about 50 ft inside an igus® Energy Chain® cable carrier (series 3500.125.200.0, with a radius of 7.9 inches).
Varied and extreme temperature curves simulated environmental influences, sometimes plunging rapidly during downtimes from plus degree temperatures to -40° F, with the test re-started immediately afterward.
Under these application conditions, the dampening of the cable was monitored to ensure it did not rise above 3 dB at 850 nm wave length. Maximum dampening – which was still under 3dB - happened after a million cycles, corresponding to an operational performance of over 4,300 miles.
The measurements highlighted in the diagram reveal that marked variations in temperature combined with the constant movement of the Energy Chain® cable carrier have only minor effects on the dampening of the CFLG.6G. The noticeably high initial dampening can be attributed to the plugs used and also reflects real-life conditions: in practice, 90% of cables used in automation are plug-in fiber-optic cables.
The test with this igus® cable reiterates that only realistic tests can provide true insight into the service life of cables.
More than 100,000 products available! Open Mon-Fri 8:00 am - 8:00 pm EST.
No minimum order | physics |
https://www.unionrope.com/applications/engineered-assemblies | 2023-09-21T18:52:50 | s3://commoncrawl/crawl-data/CC-MAIN-2023-40/segments/1695233506029.42/warc/CC-MAIN-20230921174008-20230921204008-00785.warc.gz | 0.922988 | 120 | CC-MAIN-2023-40 | webtext-fineweb__CC-MAIN-2023-40__0__226709871 | en | Below is a list of Union Tuf-GripTM Assemblies. The name Tuf-GripTM says it all. Tuf-GripTM fittings are securely attached to the wire rope by “clamping forces” that grip the rope and allow the tensile load to be transferred into the fitting. That in turn allows the load to be transferred to the point of attachment on your equipment. The result: an effective transfer of tensile forces from the rope through the fitting and into the point of attachment. To view detailed product information, click the product name. | physics |
http://www.wingsworldquest.org/blog/2011/3/4/wings-flag-carrier-robin-bell-finds-surprises-in-antarctic-i.html | 2019-07-22T13:02:04 | s3://commoncrawl/crawl-data/CC-MAIN-2019-30/segments/1563195528013.81/warc/CC-MAIN-20190722113215-20190722135215-00194.warc.gz | 0.954017 | 517 | CC-MAIN-2019-30 | webtext-fineweb__CC-MAIN-2019-30__0__48238593 | en | WINGS’ Flag Carrier Robin Bell finds surprises in Antarctic Ice
Imagine biting into a piece of cake with a thick layer of frosting at the bottom instead of at the top. Robin Bell and here team of scientists have found a similar scenario in at the bottom of Antarctic ice sheets, where freezing water is responsible for as much as half of the ice sheet’s thickness. The findings, she says, indicate that water moving through ancient river valleys beneath more than one mile of ice has changed the basic structure of ice sheets.
“We went to the middle of the ice sheet to explore the hidden mountain ranges,” Bell told WINGS, adding that, “usually the ice sheet looks like a nice pile of tortillas. Finding the frozen ice was like discovering a dollop of guacamole under the ice sheet. At first we thought is was an error but there the features were again and again.”
The study was part of a collaborative effort of seven countries to study one of the most remote parts of Antarctica, known as “Dome A.” The 4,200-meter Dome A—an area the size of California—is the top of the East Antarctic ice sheet. Large ice sheets like the one that covers Antarctica grow when falling snow accumulates faster than it disappears, over long periods of time, causing thickening and lateral spreading. But it turns out that this type of accumulation is not the only way that these ice sheets can thicken. Using state-of-the-art ice imaging systems, Bell and colleagues discovered that a large fraction of the ice at Dome A accumulated by the freezing of water at the bottom of the ice sheet, rather than from snowfall onto surface of the ice sheet. This process occurs when water pooled at the bottom of the ice sheet is cooled by convection, or when water forced up steep valley walls is super-cooled; altering the thermal and crystal structures of the ice column as well as the topography of the ice sheet surface.
Although water has long been known to be important to ice sheet dynamics (mostly as a lubricant), Bell’s study reveals just how drastically
basal water can modify the structure of ice sheets. Scientists need to understand how ice sheets are put together in order to accurately predict how they will be affected by global climate change.
Related Links and information:
Bell and her team have published the results of their study in the 03 March 2011online edition of Science magazine. http://www.sciencexpress.org. | physics |
http://www.cooktek.com/blog/how-our-drop-induction-buffet-warmers-work | 2014-09-20T13:57:43 | s3://commoncrawl/crawl-data/CC-MAIN-2014-41/segments/1410657133417.25/warc/CC-MAIN-20140914011213-00184-ip-10-196-40-205.us-west-1.compute.internal.warc.gz | 0.894322 | 401 | CC-MAIN-2014-41 | webtext-fineweb__CC-MAIN-2014-41__0__106844722 | en | How Our Drop-In Induction Buffet Warmers Work
CookTek’s innovative drop-in induction buffet warmers use induction technology to keep food warm at the buffet table. Induction heating involves an electromagnetic current that generates energy, which excites the iron molecules in the pan, and releases that energy in the form of heat. With our induction heating technology and buffet warmers, food is kept warm with precise, consistent heat – improving safety, quality and customer experience.
- Improve Safety: Our drop-in induction buffet warmers are safer than traditional heating equipment that uses canned fuel or open flames. Because CookTek’s induction warmers heat the pan or dish directly, instead of losing energy to the air the surface remains relatively cool to the touch. This makes the drop-in induction buffet warmers ideal for the front of the house, where space may be limited and many guests come into contact with the buffet warmers.
- Improve Quality: Quality food not only requires superior cooking methods and ingredients, but must also retain heat and freshness from cooktop to buffet warmer to plate. With a broad range of temperature settings and easy-to-use controls, CookTek’s buffet warmers take the guesswork out of keeping food warm on the buffet table, so that food remains hot and fresh for long periods of time.
- Improve Customer Experience: The drop-in induction buffet warmers feature a simple design that is dropped directly into countertops, eliminating the clutter of obtrusive equipment. The sleek black tops do not feature any logo, enhancing the clean, professional look of your buffet. In addition, the electronics within the units emit very little heat, eliminating the need for a cooling fan. This keeps the units “whisper quiet” in any dining room setting.
Learn more about CookTek’s wide range of induction cooking equipment and induction buffet warmers at www.CookTek.com. | physics |
http://www.guardianelevator.com.au/lift-consultants.html | 2024-04-21T07:47:33 | s3://commoncrawl/crawl-data/CC-MAIN-2024-18/segments/1712296817729.87/warc/CC-MAIN-20240421071342-20240421101342-00672.warc.gz | 0.847951 | 191 | CC-MAIN-2024-18 | webtext-fineweb__CC-MAIN-2024-18__0__167628449 | en | EMBRACING TECHNOLOGY:Guardian Elevator Services employs a comprehensive range of diagnostic hardware and software resources necessary for a consultancy specialising in the condition, operation, performance and safety of existing Lift and Escalator services.
These specialised resources include, but are not limited to:
Traffic Analysis: Lift manufacturer independent, non-proprietary Elevator Traffic Analysis & Simulation software for simulating Lift performance and determining the optimum configuration of the services in new or existing buildings.
Ride Analyser: Incorporating a 3 axis accelerometer for the measurement and recording of velocity, acceleration, jerk and lateral and vertical vibration, including FFT analysis of vibration, and the measurement of Lift travel and floor to floor heights.
Ride Analysis: Software to comprehensively analyse data collected by the Ride Analyser to quantify and diagnose the kinematics of Lift and Escalator travel. | physics |
https://www.techtuskers.com/what-is-optical-fiber/ | 2024-04-24T16:35:23 | s3://commoncrawl/crawl-data/CC-MAIN-2024-18/segments/1712296819668.74/warc/CC-MAIN-20240424143432-20240424173432-00606.warc.gz | 0.939246 | 1,191 | CC-MAIN-2024-18 | webtext-fineweb__CC-MAIN-2024-18__0__51752614 | en | Faster, more stable, more resilient, and also more sustainable.
Optical fiber has supplanted the old copper-based connectivity and revolutionized telecommunications in just a few years, supporting the greatest innovations.
Without optical fiber, there would be no broadband and ultra-broadband transmissions that allow digital streaming, augmented reality, telemedicine, robotics, and the Internet of Things.
Table of Contents
Optical fiber and companies: how to clarify
Unfortunately, it is not always easy to find clear information on this issue which is so important for companies.
In many cases, operators advertise offers talking about optical fiber without specifying real connectivity characteristics and performances.
The multiplication of technical acronyms and acronyms such as FTTH, FTTC, FTTS, FTTB, or GPON makes it even more difficult to make informed and transparent choices.
The Authority for Communications Guarantees (Agcom) has tried to clarify the subject to protect consumers and companies from forms of misleading advertising. According to Agcom, the true optical fiber is only the one that arrives directly at the user’s home or the company headquarters. But what exactly does that mean? And what is the difference between a dedicated optical fiber and a shared optical fiber? Finally, why is the operator’s role crucial in providing truly efficient connectivity for businesses?
Below you will find a small guide to help you understand what real optical fiber is, how to obtain it and how to exploit it to bring concrete benefits to your company immediately.
What is optical fiber, and how does it work
Optical fiber is a technology that allows the transmission of large amounts of data at very high speed and over very long distances through pulses of light. The technology was invented in the second half of the 1960s by Nobel laureate scientist Charles K. Kao.
Fiber optic transmission cables contain very thin transparent silicon filaments the diameter of a human hair.
Inside the cables, the filaments are isolated thanks to a mantle that facilitates the diffusion of light rays and a plastic sheath that protects the fiber’s core from atmospheric agents and other external influences.
The optical fiber needs to be “turned on” with pulses of light that translate the data into binary code, the language made up of bits used by computers. In this way, the pulses of light, pushed by repeaters located on the operators’ networks, carry large quantities of information for thousands of kilometers without degradation.
Why is optical fiber better than copper?
The performance of the fiber allowed this technology to supplant the old copper networks on which technologies such as ADSL were based.
The signals can also travel over long distances over the optical fiber without the attenuation problems typical of copper.
In addition to carrying vast amounts of information, fiber optic cables are also less susceptible to interference than copper connections that use electrical pulses to transmit data.
In this way, they do not suffer interference from humidity or rain. This insulation capacity also allows fiber cables to be installed near electrical systems in existing spaces, with economic advantages.
Fiber optic cables also make it easier to adapt services to the continuous increase in users’ bandwidth requirements.
Finally, as demonstrated by the FTTH Council Europe research, fiber-based networks are also more eco-sustainable because they require very little energy consumption.
Most devices used to spread the signals along the optical fibers do not need an electrical power supply.
Transport and access network: the last mile problem
Even if most of the operators’ offers speak generically of fiber, you have to be very careful. Not all fibers are created equal. It is good to know the difference between the transport network and the access network.
The proprietary networks of the main operators have for many years been entirely made of high-performance fiber. Suffice it to say that the first oceanic fiber cables were made in the late 1980s. Thanks to these “digital highways” – the backbones of the operators that make up the so-called transport network – data travels on the Internet worldwide to the telephone exchanges closest to users.
The road suddenly narrows because the fiber optic coverage has not yet reached the entire Italian territory in a capillary manner.
Operators do not always use fiber to connect the user’s home or company headquarters but can also use other available technologies such as copper or radio (FWA).
The technologies used to cover this step – usually called the last mile – are crucial in determining whether we are buying a true fiber offering and determining the actual performance of our access connectivity.
How to distinguish the real optical fiber
This explains why Agcom defines true fiber only as that which arrives directly at the user’s premises.
If access to the network in the last mile is made of copper, then there is no question of fiber.
To make it easier to understand what happens in the last section and therefore to identify the right offer, Agcom has created a system with stamps and color codes similar to those of a traffic light.
The stickers allow you to understand in a moment how connectivity is created in the last mile:
- red: the connection between the control unit is made entirely of copper
- yellow: the reference is made with a mixed fiber/copper system
- green: the fiber reaches the user’s home
How to check fiber coverage
The availability of fiber connectivity, therefore, depends on the network coverage. Many entrepreneurs ask themselves: How do I know when my company is reached by real optical fiber?
All operators provide online services to check which types of technology are available in the area where the company offices are located.
The AgCom has provided that, in the dedicated pages and in the commercial offers, the operators use the stamps to indicate the technologies used for the access network. | physics |
http://lan-bide.com/2020/04/30/roofs-that-make-your-home-more-efficient/ | 2020-09-18T16:42:31 | s3://commoncrawl/crawl-data/CC-MAIN-2020-40/segments/1600400188049.8/warc/CC-MAIN-20200918155203-20200918185203-00448.warc.gz | 0.953219 | 512 | CC-MAIN-2020-40 | webtext-fineweb__CC-MAIN-2020-40__0__18615300 | en | Roofing has an aesthetic quality, its colour, texture and shape either enhancing or detracting from your home's appearance. Practically, though, roofing can either increase or decrease your heating and cooling bills, depending on how it reacts to solar radiation. Here are several types of efficient roofs to consider.
If you live in a tropical climate, you might consider a cool roof—one that reflects solar radiation rather than absorbing and releasing heat. Vinyl efficiently reflects heat, but other materials, such as tiles and metal, often have reflective paint or coatings that do the job for them. A cool roof can reduce air conditioning costs and save you money. They also help mitigate the 'urban heat island effect' whereby many materials in a built-up urban environment absorb and emit heat. Collectively, this increases the overall ambient temperature in the area.
Colour plays its part also. Pale roofs reflect more heat than dark ones, though reflective coats can help dark roofs stay cool. In any case, some councils devise regulations about allowable roof hues in their region.
High Thermal Mass Roofs
If you live in an area with hot days and cold nights, you'll benefit from roofing materials with a high thermal mass, such as concrete or terracotta tiles. These substances absorb solar heat, becoming warm themselves in the process. You may notice how hot a concrete pavement, for instance, becomes under sunshine. Such thermal materials slowly release this stored-up heat hours later. They effectively work as natural heat banks, collecting and discharging heat.
High thermal mass roofs keep a home cooler in the day and warmer at night, moderating the overall fluctuations of a 24-hour cycle. Conversely, one common material that doesn't have a high thermal mass is metal. Roofs of this material don't absorb significant amounts of heat, but this makes them ideal for climates that experience both hot days and nights. A metal roof won't slowly release unwanted heat in the evening as you're trying to sleep.
A green roof is one with filled with greenery and plants that absorb the sun's heat as well as insulating your home. These roofs are constructed in layers that deal with insulation, waterproofing and drainage. A cover prevents the soil from blowing away. Plants can range from fernery to trees, in part, depending on the soil depth. Because they add to the roof weight, the building walls and roofs need to reach a required strength.
For more information about different roofing materials, talk with a professional near you. | physics |
https://safdrilling.com/electrical-resistivity-survey/ | 2023-06-03T02:30:37 | s3://commoncrawl/crawl-data/CC-MAIN-2023-23/segments/1685224648911.0/warc/CC-MAIN-20230603000901-20230603030901-00615.warc.gz | 0.910646 | 163 | CC-MAIN-2023-23 | webtext-fineweb__CC-MAIN-2023-23__0__88979538 | en | Electrical Resistivity Survey
The Electrical resistivity of the soil can be considered as a proxy for the spatial and temporal variability of many other soil physical properties (i.e. structure, water content, or fluid composition). Because the method is non-destructive and very sensitive, it offers a very attractive tool for describing the subsurface properties without digging. It has been already applied in various contexts like: groundwater exploration, landfill and solute transfer delineation, agronomical management by identifying areas of excessive compaction or soil horizon thickness and bedrock depth and at least assessing the soil hydrogeological properties. The surveys, depending on the area heterogeneities can be performed in one-, two- or three-dimensions and also at different scales resolution from the centimetric scale to the regional scale. | physics |
http://promeda.ee/product/hifu-high-intensity-focused-ultrasound/ | 2023-12-07T19:14:14 | s3://commoncrawl/crawl-data/CC-MAIN-2023-50/segments/1700679100686.78/warc/CC-MAIN-20231207185656-20231207215656-00744.warc.gz | 0.787047 | 278 | CC-MAIN-2023-50 | webtext-fineweb__CC-MAIN-2023-50__0__242599317 | en | HIFU(High Intensity Focused Ultrasound) equipment can treat a precise area with pinpoint accuracy based on the similar principle of burning a spot of black paper using magnifying glass without harming the surrounding area.
The electrical energy matched with impedance inside ULCHE is transmitted to the transducer in the cartridge and converted to ultrasonic energy. After it reach to the SMAS layer which is between the muscle layer and the subcutaneous fat layer, its thermal energy promotes collagen and makes the SMAS coagulation as well. Through this process we can lift and tighten the skin.
|Type||High Intensity Focused Ultrasound(HIFU)|
|Dimension (W x D x H)||375(W) x 440(D) x 1000(H)(mm)
|Cartridge||7.0MHz (Depth 1.5mm)
7.0MHz (Depth 3.0mm)
4.0MHz (Depth 4.5mm)
4.0MHz (Depth 6.0mm)
|Energy||0.1 – 3.0J|
|Length||5 – 25mm|
|Spacing||1.0 – 2.0mm|
|Weight||5 Kg(Cart excluded)|
|Power consumption||1kVA, 220VAC| | physics |
https://www.sanvigilio.com/en/vacation-planning/events/dolomiten-star-party_e79FBBA5EF9EC45C1B926B920240DAB6D | 2020-06-04T01:38:41 | s3://commoncrawl/crawl-data/CC-MAIN-2020-24/segments/1590347436828.65/warc/CC-MAIN-20200604001115-20200604031115-00363.warc.gz | 0.742875 | 348 | CC-MAIN-2020-24 | webtext-fineweb__CC-MAIN-2020-24__0__129285010 | en | „Dolomites Star Party“ from 26th to 31th July in San Vigilio and Alta Badia
There will be conferences as well as day and night observations. We will also search planets, comets and stars with telescopes and binoculars. The largest national and mobile planetarium will be available, witha dome of 8-meter diameter. The night of July 31 is the highlight of the astronomical observation in a magical place, the Passo delle Erbe at 2000 meters altitude, which immerses you in an extraordinary panorama of the Dolomites.
26.7. – Planetarium; Virtual reality
27.7. – Sun observation; Planetarium; Virtual reality; Musical/Multimedia show
28.7. – Sun observation; Launching of water rockets; Planetarium; Star observation at Piz da Plaies
29.7. - Sun observation; Planetarium; Virtual reality; Star observation at Sas Dlacia
30.7. – Sun observation; Launching of water rockets; Planetarium with a dome of 8 meters; Musical/Multimedia show
Passo delle Erbe
31.7. – Star observation at the Passo delle Erbe with telescopes and piano concert.
26.07.2020 09:00 - 23:00
27.07.2020 09:00 - 23:00
28.07.2020 09:00 - 23:00
29.07.2020 09:00 - 23:00
30.07.2020 09:00 - 23:00
31.07.2020 09:00 - 23:00
39030 San Vigilio & Alta Badia | physics |
https://academy.zdnet.com/sales/skill-flux-gray-magnet-shield-bundle | 2022-10-04T00:10:06 | s3://commoncrawl/crawl-data/CC-MAIN-2022-40/segments/1664030337446.8/warc/CC-MAIN-20221003231906-20221004021906-00451.warc.gz | 0.923063 | 204 | CC-MAIN-2022-40 | webtext-fineweb__CC-MAIN-2022-40__0__67588370 | en | The Skill Flux is the skill toy version of the Flux Original product. It is designed to get the most fun out of the unique anti-gravity effect. Instead of copper, it’s made of aluminum which makes the ball descend faster, allowing perfectly dynamic action between the ball and the tubes. Try keeping the ball in the air with only one tube by pulling it up when the ball is falling through, then catch it and repeat! Give one tube to a friend and try playing a game of catch. Create and learn new tricks in different styles, play fast, or go full-zen — It's easy to play but hard to master. Thanks to the stackable design, you can even create longer pipes by connecting more tubes. It's all up to you and your creativity!
WARNING: The strong magnet ball requires careful handling! Not for children under 14 years of age. Read the user manual before using the product. | physics |
https://univilltrade.hu/portfolio-item/cts-type-current-transformer/?lang=en | 2023-12-09T02:35:01 | s3://commoncrawl/crawl-data/CC-MAIN-2023-50/segments/1700679100781.60/warc/CC-MAIN-20231209004202-20231209034202-00129.warc.gz | 0.837772 | 725 | CC-MAIN-2023-50 | webtext-fineweb__CC-MAIN-2023-50__0__21991600 | en | The CTS type medium voltage post insulator current transformers manufactured by KBP Intra Sro (Czech Republic) meet the highest quality requirements.
This current transformer has been designed for indoor use on medium voltage networks. The dimensions of the device comply with relevant DIN 42600-8 standard specifications. The cast resin insulation of this current transformer is an epoxy mix which is an insulant featuring extremely good mechanical properties. The current transformer is available with one, two or three secondary windings. Versions that are reconnectable on the primary and secondary side are also available. The secondary windings are led out to a terminal board. The secondary terminal board has a lockable plastic cover. Secondary cable entry to the secondary terminals is possible through 1 pc of Pg16 packing gland.
The current transformer has a galvanized metallic structure resistant to corrosion. Its connector normally designed for earthing is equipped with a durable marking in accordance with relevant specifications.
The device is constructed in such a way that its structure cannot be dismantled and its nameplate cannot be replaced without damaging the calibration mark. The current transformer withstands thermal and dynamic impacts caused by an external short-circuit for a period set out in relevant standard.
All components, materials and parts used during the manufacturing process comply with all relevant standards being currently effective and with the generally recognized technical rules. The product does not contain any material containing PCB or asbestos, halogenated hydrocarbons and any other hazardous material to be mandatorily furnished with a descriptive symbol.
The current transformer is type tested according to EN 61869-1 and EN 61869-2 standards.
Current transformers used for metering for accounting are calibrated by MKEH (Hungarian Trade Licensing Office), Authority of Metrology.
Main technical specifications
|Maximum voltage:||12/17.5 kV, 24/25kV, 36/38,5kV|
|Power frequency withstand test voltage:||28/38 kV, 50kV, 70/80kV|
|Impulse withstand test voltage:||75/95 kV, 125kV, 170/180 kV|
|Nominal primary current:||5 – 2500 A|
|Nominal secondary current:||5 (1) A|
|Rated short time withstand current:||80 kA/1s (31,5 kA/3s)|
|Dynamic limiting current:||max 200 kA|
|Rated continuous thermal current:||120% In|
|Accuracy class – measuring core:||0.2S, 0.2, 0.5S, 0.5, 1, 3|
|Instrument safety factor – measuring core:||FS 5, FS 10|
|Number of cores with calibration capability:||3 (for versions 12/17.5 kV, 24/25kV only)|
|Accuracy class – protection core:||5P, 10P, PX|
|Accuracy limit factor – protection core:||5, 10, 15, 20, 25, 30|
|Power:||5 – 60 VA|
|Insulation temperature class:||E|
|Operating temperature:||-5 to + 40 °C|
|Storage temperature:||-50°C to +60°C|
|Standards:||EN 60044-1, EN 61869-1, EN 61869-2, GOST 15 150| | physics |
https://www.rsb.org.uk/component/content/article/161-biologist/book-reviews/1849-ecological-mechanics-principles-of-life-s-physical-interactions?Itemid=531 | 2020-09-22T21:06:26 | s3://commoncrawl/crawl-data/CC-MAIN-2020-40/segments/1600400206763.24/warc/CC-MAIN-20200922192512-20200922222512-00523.warc.gz | 0.923081 | 443 | CC-MAIN-2020-40 | webtext-fineweb__CC-MAIN-2020-40__0__170635089 | en | Ecological Mechanics: Principles of Life's Physical Interactions
Princeton University Press, £55.00
Physical principles determine many biological functions, adaptations and the carrying capacity of environments to support organisms, species and communities. Yet few biology or ecology graduates would consider mechanics theory one of their strengths. There are a limited number of texts on the fundamentals and application of mechanics written by ecologists, and fewer still that deal with topics beyond kinematics and fluid dynamics.
A sure and trusted hand is needed for confidence to travel into this unfamiliar territory. Mark Denny's comprehensive knowledge of both ecology and mechanics, and how dependent biological systems are on these physical laws, makes him a reliable guide.
The book starts with an introduction to basic principles of Newtonian mechanics, establishing a secure platform to launch from. These fundamentals are subsequently applied to transport processes including diffusion, locomotion and fluid mechanics. The clarity and simplicity with which these topics are applied to biological phenomena ensures that the reader quickly becomes aware of the relevance and potential to develop this approach to more complex ecological situations.
The necessary mathematics is taken in small steps, but the pages are not swamped with long-winded derivations (these are freely available online). There are statistical calculations to justify arguments of the influence of mechanical laws over whole habitats or ecosystems, with graphs to help visualise their significance.
The book progresses into thermal mechanics, drawing examples from desert plants, then materials science, explaining the gecko's defiance of gravity. The final section includes spectral analysis, the effects of scale and biology at the extremes. For further insight, there are regular references to authoritative texts that delve deeper, and online supplements and self-assessments that accompany each section.
Denny summarises the biological dependence of the mechanics at the end of each chapter and cautions readers on the dangers of oversimplifying when many factors are in play.
The blend of physics supported by the underlying maths, peppered with diverse biological examples, makes this book accessible reading and a most useful text. It will be valued by biologists seeking an understanding of mechanics and physical scientists applying their knowledge to large-scale living systems.
Alexander Waller CBiol MRSB | physics |
http://www.jnxqqp.com/sell/itemid-1094145.shtml | 2021-02-27T10:27:47 | s3://commoncrawl/crawl-data/CC-MAIN-2021-10/segments/1614178358798.23/warc/CC-MAIN-20210227084805-20210227114805-00238.warc.gz | 0.922276 | 256 | CC-MAIN-2021-10 | webtext-fineweb__CC-MAIN-2021-10__0__7035300 | en | Car steering gear transmission clearance T with the size of the steering wheel Angle changes. Straight line driving,
steering gear transmission pair if there is a transmission clearance, once the steering wheel by the lateral force, can be in the clearance T range,
allow the wheel to deviate from the original driving position, so that the car lose stability. In order to prevent this situation,
the transmission clearance of the transmission pair is required when the steering wheel is in the middle and near the position (generally 10°--15°) to be minimal, and it is best to have no clearance.
The wear of steering gear transmission pair in the middle and its vicinity is greater than that at both ends. When the gap
caused by wear near the middle position is too large to ensure the stability of straight line driving, the gap must be readjusted and eliminated.
For this purpose, the end of the steering rocker arm shaft adopts the T groove to install the adjustment screw to adjust the gap. After adjusting the gap,
the steering wheel can be rotated from the middle position to both ends without sticking. For this reason, the transmission clearance characteristics of the
transmission pair should be designed as a gradually increasing shape after leaving the middle position. | physics |
https://www.genmoji.com/hvac | 2019-10-17T02:57:59 | s3://commoncrawl/crawl-data/CC-MAIN-2019-43/segments/1570986672548.33/warc/CC-MAIN-20191017022259-20191017045759-00514.warc.gz | 0.883549 | 540 | CC-MAIN-2019-43 | webtext-fineweb__CC-MAIN-2019-43__0__60904485 | en | HVAC Air Recovery
Heating, ventilation and air conditioning (HVAC) units are normally the most expensive items on an electricity bill for commercial buildings. The average commercial HVAC systems range between 5 to 15 tons where each ton will control the temperature of approximately 600 sq. ft. of space. As a result, any multistory building will have multiple HVAC units running throughout the year, non-stop for 24 hours a day.
USING YOUR EXHAUST TO PRODUCE CLEAN ENERGY
Genmoji is the exclusive distributor for the Magnetic Air vertical wind turbine in PR, DR and the USVI. Our turbine can be placed in front of commercial grade HVAC exhaust fans to generate predictable, consistent and stable power output 24 hours a day. Due to our high efficiency magnetic levitation design, we can generate all the power without the need for any natural wind. The wind turbine power output using commercial HVAC systems will range between 2kW to 4.5kW depending on the age and size of HVAC system.
UNPRECEDENTED ENERGY EFFICIENCY
Our Magnetic Air wind turbine is a high-efficiency renewable electricity generation unit with unprecedented efficiency rooted in our patented design that allows the turbine’s wind blades to rotate on magnetic flux created by powerful fixed neodymium magnets. The magnets’ opposite polarities cause the turbine blades to be suspended in air while they rotate. The magnetic levitation creates a near zero-resistance environment for the main shaft, which not only makes the turbine completely silent, but it also allows it to achieve unprecedented power output and a conversion efficiency 24% greater than wind turbines using ball-bearings. This enables our turbine to generate power at lower wind speeds, spin much faster, and generate more power than a standard wind turbine. It also means that its power output can be sustained for longer periods of time and at more locations around the world.
and for our ENVIRONMENTALIST friends
Birds frequently fly into the propellers of conventional wind turbines resulting in terrible injuries and animal cruelty. Because of its compact vertical-axis cylindrical design, the Magnetic Air turbine’s blades create a vortex pressure barrier around the turbine perimeter. This vortex is very easily detected by birds insuring their safety, which facilitates EPA approvals where applicable. Additionally, in standard propeller wind turbines birds cannot see the long propellers rotating and may fly into them. With our Magnetic Air vertical axis wind turbines there are no propellers and the turbines are easily visible to birds and therefore easily avoidable like any other object. | physics |
https://trustedplumbingandheating.com/condensing-tankless-water-heater.html | 2023-11-30T00:18:04 | s3://commoncrawl/crawl-data/CC-MAIN-2023-50/segments/1700679100164.15/warc/CC-MAIN-20231130000127-20231130030127-00281.warc.gz | 0.940495 | 131 | CC-MAIN-2023-50 | webtext-fineweb__CC-MAIN-2023-50__0__302651761 | en | A condensing tankless water heater is an advanced and highly efficient water
heating system that heats water on-demand without the need for a storage tank. It utilises a heat exchanger to rapidly heat water as it flows through the unit. What sets it apart is its ability to recover and reuse heat from the exhaust gases, increasing overall efficiency. The exhaust gases are condensed to extract additional heat, thereby maximizing energy utilisation and reducing energy wastage. This process results in lower energy costs and reduced environmental impact. Condensing tankless water heaters are ideal for both residential and commercial applications where a continuous and efficient supply of hot water is essential. | physics |
https://learnmate.com.au/tutors/vce-physics-tutors-melbourne/ | 2024-03-02T23:04:35 | s3://commoncrawl/crawl-data/CC-MAIN-2024-10/segments/1707947476137.72/warc/CC-MAIN-20240302215752-20240303005752-00426.warc.gz | 0.894066 | 155 | CC-MAIN-2024-10 | webtext-fineweb__CC-MAIN-2024-10__0__10821095 | en | Excel in VCE Physics with Learnmate’s expert tutors in Melbourne. Our platform connects you with specialised VCE Physics tutors, renowned for their expertise in physics principles and innovative teaching styles, available both online and in Melbourne. Delve into their profiles to uncover their physics knowledge, teaching methodologies, and the Melbourne areas they cover, aiding you in selecting the tutor that best suits your educational needs. Our tutors, a mix of accomplished physics graduates and experienced educators, offer personalised, in-depth tutoring in VCE Physics.
Learnmate’s tutors, proficient in VCE Physics, are dedicated to enhancing your conceptual understanding, boosting your analytical skills, and refining your exam preparation, ensuring a thorough mastery of physics concepts. | physics |
https://morairinc.com/los-angeles-ca/griffith-observatory/ | 2024-04-14T04:25:05 | s3://commoncrawl/crawl-data/CC-MAIN-2024-18/segments/1712296816864.66/warc/CC-MAIN-20240414033458-20240414063458-00333.warc.gz | 0.962086 | 469 | CC-MAIN-2024-18 | webtext-fineweb__CC-MAIN-2024-18__0__183164490 | en | The Griffith Observatory in Los Angeles California is the best place to visit for stargazing and learning about space. The observatory has a large collection of telescopes to see outer space clearly, one theater room which shows documentaries about the universe, several exhibits on astronomy, Earth, and other celestial bodies, three floors of exhibits devoted to light and optics, a fabulous planetarium which shows current shows and movies, and a large projection screen which gives you a panoramic view of the city.
Learn more about out services in Los Angeles:
The Griffith Observatory was originally funded by Colonel Griffith J. Griffith in 1896 as a memorial to his wife, but it wasn’t until 1935 that it opened to the public. The observatory is at the top of Mount Hollywood in Griffith Park where it has 60 acres of land to explore. It’s located on the highest peak in the park which gives you a view of Los Angeles and its surrounding cities.
This Observatory is best known for being home to the Zeist Telescope built-in 1973, which was until 1993, one of the most powerful telescopes that could be operated by a single person. The Zeist Telescope was used to discover distant galaxies and quasars, as well as map out the celestial coordinate system.
It has an average of 1.3 million visitors every year with thousands of school-aged children on field trips. Due to its popularity, there are always lines outside of the theater room, exhibits, and planetarium but it’s worthwhile to wait. One of the most popular exhibits is about earthquakes which are simulated by speakers on the floor.
To further your knowledge of astronomy there are several inquiry programs that allow you to explore space with a group. The observatory offers tours led by astronomers who give you a detailed explanation of what you’re seeing, but they require a reservation a month in advance.
Points of Interest:
The Griffith Observatory is a place where people from everywhere can come together to find common ground and appreciate nature from all around us. So, if you’re in the Los Angeles neighborhood of Southern California it’s a must to visit Griffith Observatory!
Mor Air Inc.
11661 Saticoy Street North Hollywood, CA 91605 | physics |
https://www.batonrougeappliance.com/electrical-appliances/ | 2020-07-15T09:19:36 | s3://commoncrawl/crawl-data/CC-MAIN-2020-29/segments/1593657163613.94/warc/CC-MAIN-20200715070409-20200715100409-00484.warc.gz | 0.951272 | 1,279 | CC-MAIN-2020-29 | webtext-fineweb__CC-MAIN-2020-29__0__188114810 | en | Electrical appliances are almost everywhere, they have ended up being so widespread in our lives and our houses that it’s hard to believe they rarely were used 100 years before now. We make use of electrical power from the moment we get up in the early morning to the minute we close our eyes in the evening as well as in a lot of cases even during the night.
It is electricity that gives us light, powers our alarms as well as our handheld devices. That invisible power source that flows via cables into our houses enables us to use the toaster or turn on the coffee machine before we leave the house in the morning, it maintains our home at a comfortable temperature. We make use of it to clean our clothes and our dishes, prepare our meals and we can even travel using electric automobiles.
For many appliances in the home, electricity is the only readily available choice, for others manually operated or gas-powered options exist, yet no matter the choices it’s very difficult to envision life without electrical energy.
Not all electrical devices are created equal. Some models of electric appliances require more repair. Whatever device you are thinking about there will be hundreds of possibilities offered with a variety of costs, colors, dimensions as well as degrees of efficiency.
What are Electrical Appliances?
Simply put electrical power is the transfer of negative electrons . Electrical energy is all over. In cities, we are regularly aware of it, from the devices in our buildings to the powerlines overhead. Yet, even in the most isolated areas we still discover it as lightning or static as well as the electrical impulses that move through our bodies signalling our lungs to breath and our hearts to beat.
Ever since we have been able to capture the power of electricity people have been constantly discovering innovative methods to create it as well as to make use of it.
Electrical appliances are any devices in your house where the primary power source is electrical power. Other home appliances, such as gas appliances often still need to be wired in and also contain electrical parts but the primary fuel isn’t electrical power. For instance, a gas hob might have an electrical lighter or a gas tumble dryer still needs electric to operate the drum.
Different Kinds of Electrical Home Appliances?
We make use of major electric appliances in our residences for all types of day to day jobs consisting of heating as well as cooling our houses, refrigeration, food preparation, washing and drying, as well as heating water.
Most of us will make use of any number of these common electric home appliances:
- Dishwashing Machines
- Air conditioners
- Washing machines
- Tumble Dryers
Naturally there are innumerable other smaller appliances that we utilize to save time such as kettles, fryers, food processors, juicers, straightening irons, vacuums, humidifiers as well as coffee makers.
Benefits/Pros of Electric Home Appliances
Electricity as well as electrical home appliances have dramatically transformed the way we live in the last century. In 1925 only 50% of us had electrical energy yet these days we can hardly envision life without it and find it challenging to function during a blackout.
- Electrical power is extremely easy to distribute. It may be a large investment to get a gas line yet the reduction in the price point of photo-voltaic panels in the last few years has meant you can actually have electrical power regardless of your distance from built up areas.
- Unlike gas electrical power has a number of viable renewable options and plenty of utility companies give customers the ability to buy green energy which serves to increase demand and encourage further production.
- Electrical appliances save big swathes of time, whether it’s preparing your food, washing your clothes or heating water for a shower, life’s better with electricity.
- Electric appliances are getting more and more productive and it is now simpler than ever to choose low energy devices as they have EnergyLabels as well as the ENERGY STAR rating.
Disadvantages of Electrical Home Appliances
Certainly while electrical devices have ended up being essential to modern life, no one would desire to go back to having no refrigeration or start having to light a fire every time they needed warmth, all this simplicity does come at a cost and enhancements in modern technology could mean alternatives become more viable.
- Most electricity is still created from fossil fuels and even renewable energy sources still have an environmental impact.
- High levels of potential energy is wasted when changing the power captured in oil and coal to electrical energy we can make use of in our houses.
- Electric appliances tend to be more complex and more difficult to refurbish than mechanical devices.
- If you don’t have a backup battery or generator, even the best electric home appliances won’t work if the power goes out.
Is an Electrical Device Optimal for You?
Global warming and continued use of non-renewable energy sources has ended up being a hot subject in recent years and there are lots of reasons to wish to reduce your dependence on oil and coal by changing to better appliances or finding ways to use less power such as better insulation, taking cooler showers and drying your clothes outside.
While there are presently plentiful natural gas reserves around the United States this will not last forever and regardless of the fact that bio-methane is a possible replacement it does still release greenhouse gasses into the atmosphere.
Electrical energy isn’t going anywhere in the near future. While modern technologies are regularly getting better as to where we get our electrical power from electricity itself isn’t going to come to be obsolete just yet. You may end up harnessing your power from the sun, the wind, the waves or dams yet, it won’t change the fact that you can connect your appliances in the same way.
If you are getting new home appliances ensure you purchase the least power hungry make you can manage as this will certainly make you cash in the long run and look into smart appliances that you can manage from wherever you are and enable you to precisely keep track of power usage. If the wish to conserve energy extends to the ecological effects ask if your energy company gives a green tariff, and if they don’t switch to one that does. | physics |
https://www.maxi-cosi.com/international/node/989 | 2020-04-05T22:07:52 | s3://commoncrawl/crawl-data/CC-MAIN-2020-16/segments/1585371611051.77/warc/CC-MAIN-20200405213008-20200406003508-00311.warc.gz | 0.937773 | 140 | CC-MAIN-2020-16 | webtext-fineweb__CC-MAIN-2020-16__0__103066895 | en | Why is Rearward Facing Safer
Recent research has confirmed that babies are safer in a rearward facing seat up to the age of at least 15 months. Only then is the child?s neck strong enough to withstand the impulsive force of an average forward collision. That?s why the new i-Size regulation clearly requires using rearward-facing seats for all babies up to the age of 15 months.
If a baby travels in the car facing forwards, the relatively heavy head is unrestrained in a forward collision ? the head will be thrown forward. This can cause serious neck and head injury. Rearward facing restrains the head and spreads the impact over a greater area. | physics |
http://www.fractalacademy.com/tutors/jeffklatsky/ | 2019-05-25T09:12:02 | s3://commoncrawl/crawl-data/CC-MAIN-2019-22/segments/1558232257939.82/warc/CC-MAIN-20190525084658-20190525110658-00262.warc.gz | 0.958443 | 349 | CC-MAIN-2019-22 | webtext-fineweb__CC-MAIN-2019-22__0__139608379 | en | Jeff K. – Physics Phenom
Nuclear Physicist – The Real Deal
Physics, Physics AP, Algebra, Trigonometry, Calculus, Calculus AP, Chemistry, Math, ACT Math, SAT Math, ACT, SAT, Geometry, College Physics
Location and Rates
with Jeff K. - Physics Phenom
Remember how difficult it was the first time your physics teacher said you had to break forces down into components in order to use Newton's Second Law? Or when they asked you to find the maxima and minima of a complicated function? I sure do – I struggled with those things as well. But I found that with good teachers and some hard work, I was able to understand difficult concepts. Through my struggle, I learned how to effectively instruct students in physics and math. I have been a private tutor while I was in high school, college and graduate school, and have experience tutoring all levels of students – from elementary school students to upper level undergraduate students. I also taught physics at the college level and was nominated for an outstanding teacher aware. I am currently employed at a private tutoring company tutoring SAT/ACT math for high school students.
I have recently earned my Ph.D. in physics. I have a deep understanding of the field, as well as plenty of experience teaching it. My enthusiasm for the field is apparent in my tutoring sessions, which makes students excited to learn about it which makes tutoring and learning fun for the student.
Feel free to contact me and ask any questions you may have, whether they are about my qualifications, my teaching philosophy or anything else that comes to mind!
|Education and Credentials||
Boston College – Physics | physics |
https://systems.engr.ucr.edu/software/comsol | 2020-08-05T18:34:20 | s3://commoncrawl/crawl-data/CC-MAIN-2020-34/segments/1596439735964.82/warc/CC-MAIN-20200805183003-20200805213003-00076.warc.gz | 0.83506 | 273 | CC-MAIN-2020-34 | webtext-fineweb__CC-MAIN-2020-34__0__104158092 | en | COMSOL Multiphysics is a finite element analysis, solver and Simulation software / FEA Software package for various physics and engineering applications, especially coupled phenomena, or multiphysics. COMSOL Multiphysics also offers an extensive interface to MATLAB and its toolboxes for a large variety of programming, preprocessing and postprocessing possibilities. The packages are cross-platform (Windows, Mac, Linux). In addition to conventional physics-based user interfaces, COMSOL Multiphysics also allows for entering coupled systems of partial differential equations (PDEs). The PDEs can be entered directly or using the so-called weak form (see finite element method for a description of weak formulation). An early version (before 2005) of COMSOL Multiphysics was called FEMLAB.
ToolBoxes: SERIAL, CHEMCKL, COMSOLCKL, LLMATLABCKL, NONLINEARSTRUCTMATERIALSCKL, RFCKL, STRUCTURALMECHANICSCKL, CADIMPORTCKL, HEATTRANSFERCKL, MEMSCKL, COMSOLGUICKL, CADREADERCKL
NOTE: These installation instructions have been tested for Windows 8.1
You can download the previous versions if needed. | physics |
https://support.waterlinked.com/en/knowledge/will-waves-affect-the-performance-of-underwater-gps | 2022-01-26T04:22:55 | s3://commoncrawl/crawl-data/CC-MAIN-2022-05/segments/1642320304915.53/warc/CC-MAIN-20220126041016-20220126071016-00355.warc.gz | 0.961271 | 236 | CC-MAIN-2022-05 | webtext-fineweb__CC-MAIN-2022-05__0__110514075 | en | Waves may cause the boat to roll which may cause a degradation in performance.
If the baseline (Antenna or separate Receivers) is mounted on a boat which is rolling heavily, there are potential issues that may occur.
If using separate Receivers:
- The Receivers may move significantly from its original position which you measured and inserted in the baseline setup in the GUI. This will cause the received signal to be misinterpreted which in turn will cause the position to be less accurate.
- If you have mounted the Receivers high up in the water, they may actually be pulled out of water when the boat is rolling.
If using Antenna:
- The Antenna has fixed positions of the receivers so internal movement between them is not an issue.
- A shift in angle of the Antenna is not a huge issue as long as the angle shift is reasonably limited. A boat which is rolling heavily will pose an issue also when using the Antenna though.
- The Antenna is physically mounted to the boat using the included RAM-mount. This mount may not be able to withstand the strong forces which comes from a heavily rolling boat. | physics |
http://sabels.co.za/magnetic%20tecnical.htm | 2023-12-03T07:46:37 | s3://commoncrawl/crawl-data/CC-MAIN-2023-50/segments/1700679100489.16/warc/CC-MAIN-20231203062445-20231203092445-00284.warc.gz | 0.913335 | 1,382 | CC-MAIN-2023-50 | webtext-fineweb__CC-MAIN-2023-50__0__284960540 | en | The advent of these new materials permits the design engineer to undertake magnetic assembly designs, which were theoretically, and economically impossible several years ago. The engineer must also thoroughly evaluate his design to be certain that once the assembly is fabricated, it can be magnetised. This is especially true of multi-pole structures. In many cases the magnet can be charged prior to installation in an assembly. However, due to ferrous contamination possibilities, physical handling difficulties, and similar drawbacks, may preclude the possibility of such "pre-magnetisation".
The higher magnetising force requirements also necessitate that existing magnetising fixtures be re-designed and, in some cases, the magnetising equipment, in order to achieve the forces required. With materials having coercive forces greater than 10.000 oersteds it is generally not necessary to stabilise a structure to prevent inadvertent change of flux density levels, although treating will be required in some instances, to set or calibrate the level of flux density required. Here the potential high energy of the stored energy treater will be an added asset.
MAGNET TERMS AND DEFINITIONS
Anisotropic Magnetic Material: Also called oriented material. An anisotropic magnet has a preferred direction of magnetisation. To realise the maximum potentialities from such materials, they must be magnetised along the preferred axis. Orientation is accomplished by means of an applied magnetic field during manufacture of the material. Anisotropic materials do not have a preferred polarity orientation; i.e. either of the poles may be north or south.
Coercive Force : This is the magnetising force, in oersteds, which must be applied to a magnetic material, in a direction opposing the residual induction,
Diamagnetic Materials: This describes materials that have permeability slightly less than one. These materials tend to be slightly repelled by a magnetic field.
Ferromagnetic Materials: These materials have characteristics similar to that of iron. (Having a high degree of permeability. )
Isotropic Magnetic Materials: These materials do not have a preferred axis of magnetisation.
Magnetic Field Intensity: The strength, of a magnetic field, in air, measured at any point in a magnetic circuit, It can be measured as either oersteds or gauss’s, since, in air, B (gauss’s) numerically equals H (oersteds)in the cgs system. Thus, if we say the field in a magnetic air gap is 3000 oersteds, we are also correct in saying the same field equals 3000 gauss’s. It must be remembered, however, that B and H are two distinctly different physical phenomena, and that the numerical equality exists only in air.
Magnetising Force: This describes the magnetomotive force (force, which tends to produce a magnetic field) per unit length. Symbolised as H, the unit is called the oersted. For example: Alnico V magnet material requires a magnetising force of 3000 oersteds for saturation. In reference to magnet chargers, it is the magnetising force developed by the charging fixture, either in the air gap between charging poles, in air surrounding a magnetising conductor, or in the cavity of a solenoid-charging fixture.
Magnetic Induction: Symbolised as B (gauss’s) and is the magnetic flux per unit of a magnetic section perpendicular to the direction of flux. An interesting point to note is that if a magnet material (Alnico V for example) is placed in a magnetic field (assume 3000 oersteds in this case) the flux density in the magnet will instantaneously rise to a value B (15000 gauss’s for Alnico V), far in excess of the magnetic field in air. The relationship of B and H in air therefore no longer holds, since B is measured in a magnet material having permeability greater than the permeability of air.
Paramagnetic Materials: These are materials that have “a permeability” only slightly greater than one, usually between 1.000 and 1.001. When ferromagnetic substances are heated to a temperature above their Curie point they become paramagnetic, until their temperature is reduced to below the critical point. Such materials are said as being “feebly attracted by a magnetic field”.
Reluctance: Generally speaking, reluctance is a measure of the ability or inability of a material to transmit or carry a magnetic field. Air may be considered a high reluctance path and soft iron a path of low reluctance.
Residual Induction: The magnetic induction remaining in a permanent magnet after the magnetising force is removed. It is measured in gauss’s.
Retrace-ability: Generally refers to the ability of a magnet assembly to have a predictable flux density at any given temperature within certain limits. For example: Assume a magnet assembly to have a flux density of 2000 gauss’s at 250C after magnetic stabilisation. The structure is then subjected to temperature extremes of 0 deg. C to 1000 degree C. After the temperature cycling, the assembly may have a measured flux density of 1980 gauss’s at 250C. However, any further temperature cycling, providing the limits of 0 C and 100 C are not exceeded, will not affect the flux density at 25 degree C, i.e., 1980 gauss’s. The flux density' at any temperature between the cycling extremes, will also be retraceable. For Alnico V the flux density usually drops 0.02% per degree C rise above a specified temperature, and conversely exhibits a 0.02% per degree C increase, with lowering temperature.
Saturation: Describes the condition of a magnet when it is as fully magnetised as possible. To realise the full stability potential of a magnet it should always be saturated during charging, even though some demagnetisation may be necessary for the proper operation in the final magnetic assembly.
Stabilisation: Reducing the residual induction in a magnet to a level where it will not be affected by any demagnetising forces that may be encountered during normal operation of the finished magnetic assembly. Often called artificial aging. This is generally accomplished by subjecting the magnet assembly to an alternating magnetic field of adjustable intensity until the required flux density is reached in the magnetic air gap. Temperature stabilisation is accomplished by subjecting the magnet assembly to high and low temperature cycles, simulating the maximum temperature extremes that will be encountered by the assembly in its operating environment. Temperature cycling does not prevent changes in flux density with change of temperature, but it does allow operation of the structure with good retrace-ability characteristics. | physics |
https://astrologyandart.wordpress.com/2013/06/30/eisinga-planetarium-in-franeker-netherlands/ | 2021-05-18T11:39:30 | s3://commoncrawl/crawl-data/CC-MAIN-2021-21/segments/1620243989819.92/warc/CC-MAIN-20210518094809-20210518124809-00483.warc.gz | 0.980707 | 304 | CC-MAIN-2021-21 | webtext-fineweb__CC-MAIN-2021-21__0__103034381 | en | (photo by Roel Wijnants)
The Royal Eise Eisinga Planetarium is an 18th-century orrery in Franeker, Friesland, Netherlands. It is currently a museum and open to the public. The orrery has been on the top 100 Dutch heritage sites list since 1990 and in December 2011 was nominated as a UNESCO World Heritage Site candidate.
The Royal Eise Eisinga Planetarium in Franeker is the oldest working planetarium in the world. Its moving model of the solar system was constructed between 1774 and 1781 by Eise Eisinga, a Frisian wool-comber. It is still in its original state.
Eisinga built the planetarium in his own home. So that it would fit into his living-room, he used a scale of 1:1,000,000,000,000 (1 millimetre: 1 million kilometres).
Eisinga built the planetarium to disprove a contemporary prophecy that certain planets were on a collision course and that the end of the world was therefore imminent. He hoped his model would demonstrate that the planets were actually in conjunction. He was not a scientist in the formal sense but a creative genius who built the planetarium entirely on his own initiative.
The planetarium has always been accessible to interested members of the public. It has also received scientific recognition. All Eisinga’s books and writings have been preserved and are accessible to the public. | physics |
https://www.envioustechnology.com.au/products/product-detail.php?ID=860 | 2023-12-05T22:03:11 | s3://commoncrawl/crawl-data/CC-MAIN-2023-50/segments/1700679100568.68/warc/CC-MAIN-20231205204654-20231205234654-00413.warc.gz | 0.905011 | 232 | CC-MAIN-2023-50 | webtext-fineweb__CC-MAIN-2023-50__0__257246595 | en | Complete your Netatmo Urban Weather Station with the wind gauge
- Complete your Netatmo Weather Station
- Includes wind speed and direction
- Configure alerts to report wind speed
The Wind Gauge
Complete your Netatmo Urban Weather Station with the wind gauge.
It uses the very latest in ultrasound technology to reliably and accurately measure the wind's speed and direction, including those of wind gusts. You can configure how you want to be alerted if the wind reaches a certain speed and also receive more precise "feels like" temperature using the Weather Station App.
The Wind Gauge is equipped with four ultrasonic transducers that emit continuous signals. The Wind Gauge uses variations in these signals to reliably and accurately measure wind speed and direction.
Optional Accessories for the Netatmo Smart Anemometer for Weather Station:
The Netatmo mount makes it easier to attach your Rain / Wind Gauge to a wall, roof, pole or railing.
The Weather Station's Indoor Module measures your indoor comfort by providing vital information, alerting you when you need to air out your home to bring down its pollution levels. | physics |
http://www.ray-worldpilgrim.com/aurora-borealis/ | 2023-06-10T03:45:09 | s3://commoncrawl/crawl-data/CC-MAIN-2023-23/segments/1685224656963.83/warc/CC-MAIN-20230610030340-20230610060340-00078.warc.gz | 0.909875 | 243 | CC-MAIN-2023-23 | webtext-fineweb__CC-MAIN-2023-23__0__242308980 | en | An aurora (plural: auroras), sometimes referred to as polar lights, northern lights (aurora borealis) or southern lights (aurora australis), is a natural light display in the Earth’s sky, predominantly seen in the high latitude (Arctic and Antarctic) regions.
Auroras are produced when the magnetosphere is sufficiently disturbed by the solar wind that the trajectories of charged particles in both solar wind and magnetospheric plasma, mainly in the form of electrons and protons, precipitate them into the upper atmosphere (thermosphere/exosphere) due to Earth’s magnetic field, where their energy is lost.
The resulting ionization and excitation of atmospheric constituents emits light of varying color and complexity. The form of the aurora, occurring within bands around both polar regions, is also dependent on the amount of acceleration imparted to the precipitating particles. Precipitating protons generally produce optical emissions as incident hydrogen atoms after gaining electrons from the atmosphere. Proton auroras are usually observed at lower latitudes.
Fortunately I could see these Northern Lights in the Arctic Sky at Tromso, Norway on 18th October, 2017. | physics |
https://bestautoaccs.com/top-window-tinting-materials-for-energy-efficiency/ | 2024-02-23T06:58:12 | s3://commoncrawl/crawl-data/CC-MAIN-2024-10/segments/1707947474361.75/warc/CC-MAIN-20240223053503-20240223083503-00034.warc.gz | 0.921614 | 541 | CC-MAIN-2024-10 | webtext-fineweb__CC-MAIN-2024-10__0__30021862 | en | Window tinting is an effective way to make your home or office more energy-efficient. It can help you save on energy bills and reduce your carbon footprint. However, not all window tinting materials are created equal.
Let’s take a look at the top window tinting materials:
- Ceramic Tinting Film
Ceramic tinting film is one of the most energy-efficient options on the market. Made with advanced nano-ceramic technology, this film blocks up to 99% of UV rays, which can cause fading and damage to furniture, flooring, and artwork. It also blocks significant amount of heat, keeping your interior cool and comfortable even on the hottest days. Additionally, ceramic tinting film is highly durable and scratch-resistant, making it an excellent investment for the long term.
- Low-E Film
Low-E (low emissivity) film is another popular choice for energy-efficient window tinting. This film is designed to reflect infrared heat back into the room, keeping your interior warm and cozy during the colder months. In summer, it blocks up to 99% of UV rays and solar heat, keeping your interior cool and comfortable. Additionally, the film reduces glare and increases privacy, making it a versatile option for any space.
- Spectrally Selective Film
Spectrally selective film is a highly advanced window tinting material that uses a combination of dyes and metals to selectively block specific wavelengths of light. This allows it to block harmful UV rays and solar heat without blocking out visible light. The film is highly effective at regulating temperature, reducing glare, and increasing privacy.
- Dual-Reflective Film
Dual-reflective film is a type of window tinting that has a highly reflective surface on both sides of the film. This allows it to block out a significant amount of heat and glare while still allowing natural light to pass through. It’s a great choice for buildings with high levels of foot traffic, as it can help prevent people from peering in.
- Metalized Film
This film is made with a thin layer of metal that reflects heat and UV rays away from your interior, keeping it cool and comfortable. Metalized film is highly durable and scratch-resistant, making it an excellent choice for high-traffic areas. However, it should be noted that metalized film can interfere with wireless signals, so it may not be the best choice for homes or offices that rely heavily on wireless technology.
By opting for TechTeinte commercial window tinting, you can enjoy the benefits of reduced energy costs, increased privacy, and improved comfort all year round. | physics |
https://bowclub.se/products/galilei-bow-tie | 2019-05-27T11:22:18 | s3://commoncrawl/crawl-data/CC-MAIN-2019-22/segments/1558232262369.94/warc/CC-MAIN-20190527105804-20190527131804-00157.warc.gz | 0.960785 | 108 | CC-MAIN-2019-22 | webtext-fineweb__CC-MAIN-2019-22__0__184696588 | en | Galilei bow tieBC-1802-202 €50,00
Bow Club Galilei bow tie has our classical diamond shape and is self-tied. It is in exquisite woven cotton. It comes in a beautiful gift box.
This item is named after the father of modern science. Galileo Galilei discovered the first moons ever known to orbit another planet and that the Milky Way is made of stars. He rationalized how objects are affected by gravity, stated the principle of inertia, and proposed the first theory of relativity. | physics |
https://ananthrachakonda.com/projects/STASIA/ | 2024-02-24T13:40:27 | s3://commoncrawl/crawl-data/CC-MAIN-2024-10/segments/1707947474533.12/warc/CC-MAIN-20240224112548-20240224142548-00243.warc.gz | 0.914705 | 184 | CC-MAIN-2024-10 | webtext-fineweb__CC-MAIN-2024-10__0__43982482 | en | STASIA is a two-wheeled self-balancing robot. The dynamics of the STASIA are similar to a classic control problem, the inverted pendulum. It uses stepper motors in each wheel powered by an external supply. Balance is achieved using feedback from the gyroscope and the accelerometer on the IMU board. The wheels are driven forward or backward as needed to return the robot’s pitch to the upright position. Find the video demonstration by clicking on the image thumbnail to the left(/top).
The objective of this project is to demonstrate the performance of PD control on an underactuated nonlinear system – the inverted pendulum – through a two-wheeled robot designed to emulate this phenomenon. Disturbance rejection – the disturbance is induced in the form of a finger-nudge onto one of the faces of the robot control system – is demonstrated in the video. | physics |
https://esldrill.com/a-truly-beautiful-mind-quiz/ | 2023-11-29T07:45:06 | s3://commoncrawl/crawl-data/CC-MAIN-2023-50/segments/1700679100057.69/warc/CC-MAIN-20231129073519-20231129103519-00723.warc.gz | 0.983972 | 1,304 | CC-MAIN-2023-50 | webtext-fineweb__CC-MAIN-2023-50__0__308631043 | en | Check your comprehension. Answer all the questions.
Your name and School:
Summary of the text ‘A truly beautiful mind’.
Albert Einstein: From a Unique Childhood to a Scientific Revolution
Albert Einstein, one of the most renowned scientists of all time, had an extraordinary journey that began in the German city of Ulm on March 14, 1879. However, his early life did not hint at the greatness he would later achieve. In fact, his own mother considered him unusual due to his seemingly oversized head.
Einstein’s childhood was marked by some peculiar traits. At the age of two-and-a-half, he had not yet spoken. When he finally uttered his first words, he repeated everything twice. His playmates even nicknamed him “Brother Boring” because he struggled to interact with other children. Instead, he preferred to engage with mechanical toys, often expressing curiosity about how things worked. For instance, upon seeing his newborn sister, Maja, he remarked, “Fine, but where are her wheels?”
Despite these initial challenges, Einstein’s brilliance began to emerge. A story recounted by the historian Otto Neugebauer shed light on his unique character. As a late talker, Einstein’s parents were understandably concerned. However, during one dinner, he suddenly broke his silence, saying, “The soup is too hot.” When asked why he had remained quiet for so long, Einstein responded, “Because up to now, everything was in order.”
Einstein’s academic journey was not without its setbacks. A headmaster once told his father that Albert would never succeed in any profession. However, this prediction did not deter him. At the age of six, he started learning to play the violin, a skill he would maintain throughout his life, thanks to his mother’s encouragement.
While Einstein may not have been a model student, he excelled academically. He attended high school in Munich after his family moved there when he was just 15 months old. He consistently earned good grades in nearly every subject. However, he despised the rigid structure of the school and often clashed with his teachers. His dissatisfaction reached a breaking point at age 15 when he decided to leave school for good.
In the previous year, Einstein’s parents had relocated to Milan, leaving him in the care of relatives. After careful deliberation, Einstein persuaded his family to allow him to continue his education in German-speaking Switzerland, a more liberal environment than Munich.
Einstein’s fascination with mathematics and physics led him to choose Zurich for his university studies. However, his interests extended beyond science. He developed a unique connection with a fellow student, Mileva Maric, a brilliant young woman from Serbia. At that time, Zurich was one of the few European universities where women could pursue degrees, and Einstein recognized in Mileva an ally against the conservative elements in his family and university.
Einstein and Mileva’s relationship blossomed, blending science with tenderness in their letters to each other. They dreamt of jointly achieving success in the field of relativity.
In 1900, at the age of 21, Einstein found himself a university graduate without employment. To make ends meet, he worked as a teaching assistant, gave private lessons, and, in 1902, secured a job as a technical expert in the patent office in Bern. This seemingly ordinary job turned out to be a fertile ground for his burgeoning ideas. In fact, he humorously referred to his desk drawer as the “bureau of theoretical physics,” where he secretly developed his groundbreaking theories.
One of Einstein’s most famous works emerged in 1905 with the publication of his Special Theory of Relativity. This theory challenged the previously held notions of time and distance, suggesting that these concepts were not absolute. According to his theory, two perfectly accurate clocks would not show the same time if they reunited after one had been moving very fast relative to the other. This groundbreaking work introduced the world to the famous equation E=mc^2, which describes the relationship between mass and energy.
While Einstein was making monumental strides in physics, his personal life faced difficulties. He had wanted to marry Mileva immediately after finishing his studies, but his mother’s objections and concerns about Mileva’s intelligence led to a delay. They eventually married in 1903 and had two sons. However, their marriage began to falter a few years later. Mileva’s diminishing intellectual ambitions and her growing unhappiness as a housewife culminated in their divorce in 1919. That same year, Einstein married his cousin, Elsa.
Einstein’s personal transformation coincided with his ascent to worldwide fame. In 1915, he published his General Theory of Relativity, offering a fresh interpretation of gravity. In 1919, during a solar eclipse, evidence supporting the accuracy of his theory emerged when he correctly calculated how the sun’s gravitational field would deflect the light from fixed stars. Newspapers hailed his work as a “scientific revolution.”
In recognition of his contributions to physics, Einstein was awarded the Nobel Prize in 1921, and he received numerous honors and invitations from around the world.
When the Nazis seized power in Germany in 1933, Einstein emigrated to the United States. Five years later, the discovery of nuclear fission in Berlin raised concerns among American physicists. Many of them had fled from fascism, like Einstein, and feared that the Nazis might build and use an atomic bomb.
Einstein, deeply affected by the devastating potential of nuclear weapons, wrote a letter to President Franklin D. Roosevelt in 1939, warning of the destructive power of atomic bombs. This led to the U.S. launching its own secret atomic bomb project, resulting in the bombings of Hiroshima and Nagasaki in 1945.
In response to the widespread destruction caused by these bombings, Einstein wrote to the United Nations, proposing the establishment of a world government to promote peace and disarmament. Although his letter did not have an immediate impact, Einstein continued to engage in political activism, advocating for peace and democracy.
When Albert Einstein passed away in 1955 at the age of 76, he was celebrated not only as a scientific genius but also as a visionary and a world citizen who had left an indelible mark on both the scientific and political landscapes of his time. | physics |
http://www.tommywonk.com/2009/06/more-on-reflective-roof-coatings.html | 2017-04-23T05:24:53 | s3://commoncrawl/crawl-data/CC-MAIN-2017-17/segments/1492917118477.15/warc/CC-MAIN-20170423031158-00458-ip-10-145-167-34.ec2.internal.warc.gz | 0.895631 | 261 | CC-MAIN-2017-17 | webtext-fineweb__CC-MAIN-2017-17__0__287449960 | en | Most existing flat roofs are dark and reflect only 10 to 20% of sunlight. Resurfacing the roof with a white material that has a long-term solar reflectance of 0.60 or more increases its solar reflectance by at least 0.40. Akbari et al. estimate that so retrofitting 100 m2 (1000 ft2) of roof offsets 10 tonnes of CO2 emission. (For comparison purposes, we point out that a typical US house emits about 10 tonnes of CO2 per year.) Emitted CO2 is currently traded in Europe at about $25/tonne, making this 10-tonne offset worth $250.
On a summer afternoon, central Los Angeles registers temperatures typically 5°F higher than the surrounding suburban and rural areas. Hot roofs and pavements, baked by the sun, warm the air blowing over them. The resulting urban "heat island" causes discomfort, hikes air-conditioning bills, and accelerates the formation of smog.
This accumulation of heat is not due solely to urban density:
Contrary to popular opinion, heat islands do not arise mainly from heat leaking out of cars, buildings, and factories. In summertime, such anthropogenic heat gain accounts for a mere 1 percent of the heat island's excess temperature. | physics |
http://www.caad.arch.ethz.ch/blog/caad-praxis-hs2013/ | 2019-08-25T13:15:27 | s3://commoncrawl/crawl-data/CC-MAIN-2019-35/segments/1566027330233.1/warc/CC-MAIN-20190825130849-20190825152849-00025.warc.gz | 0.927689 | 512 | CC-MAIN-2019-35 | webtext-fineweb__CC-MAIN-2019-35__0__224739737 | en | What does the wall think it is??
Usually when we think about the sound of a built environment, we see it as an interplay between materiality of the environment and dynamic forces acting upon it. Materials are usually thought to be passive sound articulators with certain physical characteristics, which make them resonate and sound in a certain, pre-specified way. Architectural acoustics are on the side of optimization, selecting the “right” materials for the purpose and arranging them in the “right” way. Let’s invert this story!
What if our real-world materials could sound, not just as they are physically encoded, but how ever we wanted them to sound? What if stone could sound like wood, or a glass plate as a metal string? Can we design our buildings to sound different in the morning than in the evening? Can the sound of our buildings be adaptive? The answer is – yes!
The goal of this class is to teach you the concepts and technology to design adaptive soundscapes: Sound waves and analogue-to-digital (A/D and D/A) conversion; Ambisonics (a multi-channel audio array) to move a sound source through a fictive room; Audio transducers, to extend or change the sound of matter; Contact microphones or piezo elements to hear the smallest nuances of matter, record it and dope them electronically afterwards; Hydrophones to record sounds under water; Transparent sound film to create new kind of speakers; Ultrasonic sound-beams to define who gets to hear something and who doesn’t; Kinect cameras to track the movements and usage of spaces; At the end, we will learn how to design interfaces on our tablets to transform our sonic environments.
In this course we will be using Max/MSP as audio programming software, as well as Processing for general programming. Those who are already familiar with Max/MSP and Processing – or are interested in learning it – are very welcome to participate in the programming part. For all others, we provide some stand-alone applications as working templates. Besides motivation, there are no prerequisites for the technical part of this course.
|number||max. 20 / min. 10 motivated students|
|dates||Mondays, 15:00 – 17:00|
|place||Chair for CAAD, HPZ, Floor F unless announced differently|
|tutors||Nikola Marincic, Thomas Schmalfeldt| | physics |
https://aiusthemaine.wordpress.com/2012/10/ | 2019-07-22T23:04:28 | s3://commoncrawl/crawl-data/CC-MAIN-2019-30/segments/1563195528290.72/warc/CC-MAIN-20190722221756-20190723003756-00384.warc.gz | 0.979311 | 570 | CC-MAIN-2019-30 | webtext-fineweb__CC-MAIN-2019-30__0__140169270 | en | Recently, I have discovered the works / discoveries of one of the most famous Astrophysicist that we have today, Dr. Neil DeGrasse Tyson. I was really unaware of his works, so ignorant that I only knew him through his famous “watch out we got a badass over here” meme.
I learned that he is the current Director of Hayden Planetarium in New York City and he also has an educational TV show named NOVA Science NOW. He also has a radio show entitled “StarTalk” which talks about almost anything about Astrophysics. Which I also found out is in Podcast which you can download for free.
Now on the video, last week I was browsing videos on YouTube and I stumbled upon this “The Most Astounding Fact” video by Dr. Tyson. He was asked by the interviewer what is the most astounding fact about the universe. This was actually an excerpt from his 10 Questions interview with TIME Magazine.
Basically he answers the question and explains that the atom that we have which is present here on earth and in our body (nitrogen, oxygen and carbon etc.) is also present in the universe. In fact, those three elements are the most basic components of the universe. He further explains that an unstable star which go supernova/explodes scatters most of these elements in the universe. Which then become gas clouds that form the next generation of solar systems, planets and bring life itself. He further discuss that he feels a certain level of connectivity with the universe knowing that what we are made of is basically what is most present in the universe.
Dr. Tyson explains what he really feels about that fact and how astounding it is, knowing such. The video has been cleverly done, as while he is explaining his answer, a series of video footages and stills from space (taken from the Hubble telescope), landscapes, seascapes and other sceneries are being shown. The background music entitled “To build a home” was also a perfect song fit for this video.
It gives you that light positive feeling by just watching it. It actually feels very spiritual. And for sure some individuals, including myself, also did feel that level of connectivity between us and the universe.
It is very inspiring and it gives you hope and vibrant energy. I myself have watched this video several dozens of times. I was so fond of it that I even downloaded it and saved it on my iPod. And whenever I feel down and just need like a motivation or something that can get me back on track, I just sit back and watch this.
View the video and be the judge for yourself and hopefully you will also have a satisfying realization.
Kudos to Mr. Max Schlickenmeyer for editing and making this video happen! | physics |
http://sustainablesisters.blogspot.com/2016/12/moving-forward-into-diamond-age-of.html | 2018-05-27T01:37:46 | s3://commoncrawl/crawl-data/CC-MAIN-2018-22/segments/1526794867977.85/warc/CC-MAIN-20180527004958-20180527024958-00102.warc.gz | 0.927999 | 111 | CC-MAIN-2018-22 | webtext-fineweb__CC-MAIN-2018-22__0__57216968 | en | Monday, December 19, 2016
Moving forward into a 'Diamond-age' of Power Generation
Thanks to a team of physicists and chemists from the University of Bristol who have developed new technology that uses nuclear waste to generate electricity in a nuclear-powered battery. By growing a 'diamond' which, when placed in a radioactive field, can generate an electrical current. This fantastic development is a step forward in solving the challenges our world faces in dealing with nuclear waste, producing cleaner electricity and batteries. For more information you can click on this link. | physics |
https://www.murphy.art/products/lightning-120x120cm | 2024-04-21T23:12:42 | s3://commoncrawl/crawl-data/CC-MAIN-2024-18/segments/1712296818067.32/warc/CC-MAIN-20240421225303-20240422015303-00490.warc.gz | 0.915618 | 144 | CC-MAIN-2024-18 | webtext-fineweb__CC-MAIN-2024-18__0__153640604 | en | Artist: Sarrita King
Medium: Acrylic on Linen
Sarrita’s Lightning paintings are a painted memory of the electrical storms in the tropical climate of Darwin where Sarrita spent her youth. The lightning would crack across the entire sky, creating lines not dissimilar to cracked earth. And with the lightning came the winds that in their fury whipped up all the dust, rain, heat and magnetic energy into a maelstrom in the air. Sarrita would discover new patterns and colours every time she witnessed these natural light shows.
Shipping Calculated at Checkout | physics |
https://cradleofaviationpr.org/about-the-design-of-the-lunar-moduel/ | 2021-10-17T04:00:05 | s3://commoncrawl/crawl-data/CC-MAIN-2021-43/segments/1634323585120.89/warc/CC-MAIN-20211017021554-20211017051554-00235.warc.gz | 0.9706 | 359 | CC-MAIN-2021-43 | webtext-fineweb__CC-MAIN-2021-43__0__234442666 | en | Designed solely for the one-sixth gravity and vacuum of the Moon, it had to be a new type of spacecraft, unlike anything that had every been built.The design went through several configurations over the years to save weight and consider unknown Lunar conditions and kept evolving through each successive mission. It had to be small enough to fit inside the Saturn V rocket and light enough to be launched into space. It had four widely-spaced legs so it couldn’t tip over and big footpads so it wouldn’t sink.
Each LM consisted of an ascent stage and a descent stage, with both stages functioning as a single unit after separation from the Command Module through descent, landing, and stay on the lunar surface. The descent stage then served as the launch platform from which the ascent stage lifted off the moon. Interstage fittings were severed by explosives, so that the ascent stage then operated as an independent spacecraft during liftoff, ascent, rendezvous, and docking with the Command Module in lunar orbit. Thermal and micrometeroid shields also covered the decent stage. This shield, of aluminized Mylar, agave the craft a fragile, almost flimsy appearance. The ascent stage was the control center of the LM, with position for two astronauts. It contained the systems required for navigation, control, communications, life support, electrical power, and propulsion. The descent stage, the unmanned portion of the LM, carried the scientific equipment and experiments that were used on the lunar surface, as well as the descent propulsion. system.
The Lunar Module was the first true spacecraft, performing its mission only in the vacuum of space. Because of this, it could be designed to be purely functional, without streamlining-no aerodynamic qualities were necessary. | physics |
https://milestorow.com/products/the-solar-system-with-el-sistema-solar-con-ellen-english-and-spanish-edition | 2024-03-04T07:46:19 | s3://commoncrawl/crawl-data/CC-MAIN-2024-10/segments/1707947476432.11/warc/CC-MAIN-20240304065639-20240304095639-00164.warc.gz | 0.875823 | 126 | CC-MAIN-2024-10 | webtext-fineweb__CC-MAIN-2024-10__0__151957674 | en | Introduce the universe to your baby through this charming bilingual book, which will show them the sun, moon, and planets in English and Spanish.
Take a trip around our solar system with Ellen Ochoa, the first Latina in the world to travel into space. This book introduces little ones to the sun, moon, and planets with simple facts in English and Spanish.
The Solar System with/El Sistema Solar con Ellen is a wonderful bilingual board book that celebrates the contributions of an incredible trailblazer while introducing little ones to our solar system.
Available as a bilingual (English/Spanish) board book | physics |
http://altenburgpiano.com/piano-services/tuning | 2018-04-26T01:57:59 | s3://commoncrawl/crawl-data/CC-MAIN-2018-17/segments/1524125948047.85/warc/CC-MAIN-20180426012045-20180426032045-00614.warc.gz | 0.95816 | 284 | CC-MAIN-2018-17 | webtext-fineweb__CC-MAIN-2018-17__0__104127600 | en | WHAT IS TUNING?
Tuning is the adjustment made to the tuning pins by the piano tuner to bring each string to its proper tension. There are approximately 230 separate strings on the piano, each with a total of between 160 and 200 lbs. of tension.
The standard international pitch is 440 cycles (or vibrations) per second. This is the pitch that sounds when “A” above middle “C” is played thus we call it A440.
If a piano is allowed to go 1/2 step below pitch, it can mean a difference of 3000 to 5000 lbs. of tension on the strings and plate. When your tuner tells you your piano needs a pitch raise, he means the tension needs to be increased so he can bring the sound back to standard pitch (A440).
HOW OFTEN SHOULD I TUNE MY PIANO
All pianos go out of tune whether they're played or not because of expansion and contraction of the wood due to atmospheric changes. A good rule of thumb for a piano in a home near my location would be twice a year – when the heat is turned on for the winter and then again when turned off for the spring.
Really the best answer is “As often as the user feels it is necessary” and pianos used in concerts, recording studios, TV and radio are tuned before each performance. | physics |
https://www.soundtubetesting.com/ | 2023-05-28T10:14:59 | s3://commoncrawl/crawl-data/CC-MAIN-2023-23/segments/1685224643663.27/warc/CC-MAIN-20230528083025-20230528113025-00632.warc.gz | 0.941851 | 473 | CC-MAIN-2023-23 | webtext-fineweb__CC-MAIN-2023-23__0__159576086 | en | May 30, 2017
Cofrend 2017 Conference & Exhibition Strasbourg, France
Sound Tube Testing participates from the 30th of May until the 1st of June 2017 at the Cofrend days which are held in Strasbourg, France. Together with our partners Dekra-Industrial, we demonstrate the brand-new device Sonic V at the Dekra booth during this most important NDT event in France.
Sound Tube Testing carries out inspections worldwide. We are the experts in the use of APR (Acoustic Pulse Reflectometry). APR is the fastest leak detection technology in the world and has also been designed to achieve full coverage of all ID defects in all tube types, regardless of shape or material. We collect data with an average of 250 tubes an hour and we provide you with a report on your desk within 24 hours!
As the experts in the use of sound waves for tube inspections, we analyzed and reported already well over a million tubes from different applications in different industries. Our very experienced analysts not only analyze & report data collected by our own team during our own inspections, but increasingly analyze data collected by technicians from asset-owners or colleague service providers in order to provide them very fast with the best possible report.
Now introducing inspections with the Sonic V
Produced by Sound Wave Inspection Systems, Sound Tube Testing now performs inspections with the new Sonic V.
The Sonic V is the latest generation APR inspection system. The system is much more advanced than the Dolphin G3 system we used in the last few years: much lighter to handle, working without cables, better hardware, better software and therefor better results.
Another improvement of this new equipment is the ease of use and the ease of transportation. The Sonic V now has everything in one backpack of 8 Kg! The total package is including the probe, 2 rechargeable batteries and adapters for inspections from 6mm ID up to 50mm ID and is so easy to transport!
March 12, 2017
RAKK 2017 Conference Eger, Hungary
Sound Tube Testing participates from the 22nd – 24th of March 2017 at the exhibition which is held during the RAKK 2017 conference in Eger, Hungary. Together with our longtime partners in Hungary, Ke-Tech Kft., we demonstrate the brand-new device Sonic V. | physics |
http://www.sunhakpeaceprize.org/en/news/laureates_news.php?code=board&idx=657&bgu=view | 2024-02-25T11:16:25 | s3://commoncrawl/crawl-data/CC-MAIN-2024-10/segments/1707947474595.59/warc/CC-MAIN-20240225103506-20240225133506-00694.warc.gz | 0.937095 | 711 | CC-MAIN-2024-10 | webtext-fineweb__CC-MAIN-2024-10__0__119387807 | en | Researchers, technicians, students and support staff responsible for the development of the Oxford-AstraZeneca vaccine have been awarded the Royal Society’s Copley Medal for their rapid development and deployment of a vaccine against Covid-19.
This is the first time in the nearly 300-year history of the Copley Medal that it has been awarded to a team.
As the latest recipients of the Society’s most prestigious award, the Oxford-AstraZeneca Vaccine Team will join figures recognised for their exceptional contributions to science, including Louis Pasteur, Dorothy Hodgkin, Charles Darwin, Albert Einstein, and Jocelyn Bell Burnell.
Accepting the Copley Medal on behalf of the team*, Professor Dame Sarah Gilbert DBE, Saïd Professor of Vaccinology at the University of Oxford, said: “It is wonderful to receive this recognition for the team that developed the Oxford-AstraZeneca Covid vaccine.
“When work started on the vaccine in 2020, we needed to bring together people with complementary expertise to allow us to move quickly and plan many stages ahead. Many people worked extremely hard for a very long time, and winning this prize lets the whole team know how much their dedication is appreciated.”
Other recipients of the Society’s 2022 prizes awarded for their involvement in the Covid-19 pandemic include Professor Sir Jonathan Van-Tam MBE FMedSci, who receives the David Attenborough Award and Lecture for his public engagement work, and Professor Graham Medley OBE who was awarded the Gabor Medal, in recognition of his team’s epidemiological modelling contributions.
The Royal Society introduced two new annual prizes in 2022, celebrating the work of technicians and those who work to improve research culture. A number of winners this year showcase these wider contributions to the scientific effort:
- University of Nottingham chemistry research technician, Neil Barnes, receives the inaugural Hauksbee Award, in recognition of his role in supporting generations of physical chemists as a research technician, including as a demonstrator on the YouTube chemistry channel, Periodic Videos.
- Dr Diane Saunders, John Innes Centre, is awarded the Rosalind Franklin Award and Lecture, for her mentoring project to empower female undergraduate and early career researchers in plant sciences.
- Dr Mark Richards, Imperial College London, is recognised for his commitment to increasing equity in physics through the development of the UK’s first network of Black physicists, the Blackett Lab Family, with the inaugural Royal Society Research Culture Award.
- The UCL STEM Participation and Social Justice team, is aiming to make STEM more inclusive, accessible and equitable for all young people, and receive the Athena Prize.
Sir Adrian Smith, President of the Royal Society said, “On behalf of the Royal Society, I offer my congratulations to the outstanding researchers, individuals and teams whose contributions to our collective scientific endeavour have helped further our understanding of the world around us.
"Science has always been a team game, and I’m proud to see such a wide array of skills and specialisms reflected in this year’s medals and awards.
“From the original ideas that open up new fields, to the team effort that delivered the Oxford-AstraZeneca vaccine, or the vital work of technicians and those opening doors for the next generation of talented researchers – I am proud that we can celebrate outstanding scientific contributions in all their forms.” | physics |
https://ruiefdasilva.wixsite.com/ruiefdasilva | 2021-07-23T17:54:34 | s3://commoncrawl/crawl-data/CC-MAIN-2021-31/segments/1627046150000.59/warc/CC-MAIN-20210723175111-20210723205111-00701.warc.gz | 0.897903 | 129 | CC-MAIN-2021-31 | webtext-fineweb__CC-MAIN-2021-31__0__225070364 | en | Rui E. F. Silva
I am a postdoc researcher working on the ERC funded project MMUSCLES, under the supervision of Dr. Johannes Feist.
In my PhD, I have done research on the field of Strong Field Physics, in particular, I was focused in strong field phenomena (photoionization and high harmonic generation) in diatomic molecules. More recently, I am interested in the process of high harmonic generation in solid targets and how electron-electron correlation affects this process.
My research interests are in the areas of Atomic, Molecular and Optical Physics, Condensed Matter Physics and Computational Physics. | physics |
https://www.eu-citizen.science/project/46 | 2023-09-21T20:03:31 | s3://commoncrawl/crawl-data/CC-MAIN-2023-40/segments/1695233506029.42/warc/CC-MAIN-20230921174008-20230921204008-00367.warc.gz | 0.920997 | 542 | CC-MAIN-2023-40 | webtext-fineweb__CC-MAIN-2023-40__0__156075874 | en | The Star-Spotting Experiment (Stjärnförsöket)
Our use of artificial light has dramatically changed the environment in large parts of the world. Scientific studies have shown unexpected and worrying effects on the biology of many organisms as well as on whole ecosystems, but also on human health. The problems of artificial light are commonly referred to as light pollution. In the Star-Spotting Experiment, thousands of pupils, members of outdoor associations, other clubs and members of the public in Sweden, UK, Ireland and Spain contributed to scientific research about light pollution by counting stars in the sky, while discovering the level of light pollution in their own neighbourhood. Participants used a cardboard tube (e.g. a kitchen paper roll), a bit of string, tape and a protractor to construct a measuring tube. They then observed the night sky through the tube and counted visible stars in a number of directions. Directions were determined by means of a compass, and all results were reported via a smartphone app. The project was run as part of ForskarFredag – the Swedish events during the European Researchers' Night.
The Star-Spotting Experiment was created by the non-profit organisation VA (Public & Science), the National Resource Center for Physics Education (NRCF), Lund University, Kristianstad University, the Swedish National Space Agency, and the two science centres House of Science (Vetenskapens hus) and Umevatoriet, Sweden. The project was run in collaboration with Fundación Descubre, Esciencia, La Palma Centre and Fundación madri+d in Spain, University College Cork and Trinity College in Ireland and Natural History Museum in London, UK.
The aim of the Star-Spotting Experiment was to measure and map light pollution at a local level, by means of an easy-to-use method and a smartphone app.
• A simple cardboard tube, such as a kitchen or toilet paper roll. It is important that you know the length and diameterof the tube.
• A compass, either on a mobile app or a classic analogue compass.
• An Internet connection and a computer or the Star-Spotting Experiment app, which is available for both mobile and tablet.
• Protractor, string and a weight (e.g. a nut).
• Information about what time the sun sets where you are. There are apps and websites which provide this information (eg the Sunrise Sunset Lite app).
Profile image design by: VA (Public & Science) | physics |
https://nsrc.lanl.gov/oppenheimer/ | 2023-10-04T14:17:30 | s3://commoncrawl/crawl-data/CC-MAIN-2023-40/segments/1695233511369.62/warc/CC-MAIN-20231004120203-20231004150203-00537.warc.gz | 0.934724 | 522 | CC-MAIN-2023-40 | webtext-fineweb__CC-MAIN-2023-40__0__185617886 | en | Physicist J. Robert Oppenheimer will forever be known as the “father of the atomic bomb.” At Los Alamos, though, he was much more.
Watch the full story of J. Robert Oppenheimer and his work on the Manhattan Project as only the Los Alamos National Lab can tell it.
An undisputed genius. A revered leader. A charmer and a storyteller.
Oppenheimer came to the clandestine Lab in northern New Mexico as its first Director in 1943, hired by General Leslie Groves to accomplish a monumental feat: create the atomic bomb as quickly as possible to help end World War II. In just 27 months, Oppenheimer led his team to do just that, changing the world and affirming his scientific legacy.
In 1954, however, the U.S. Atomic Energy Commission revoked Oppenheimer’s security clearance, alleging he had ties to communism. His final years were spent quietly before his death at age 62 in 1967.
In late 2022, U.S. Secretary of Energy Jennifer Granholm signed an order vacating the 1954 decision to revoke Oppenheimer's security clearance. Read more about what many considered an unfair political and personal attack, including details on the history and Granholm's statement.
About the documentary
“Oppenheimer: Science, Mission, Legacy” is produced by the NSRC and highlights the impetus for the Manhattan Project’s creation and Los Alamos National Laboratory’s continuing mission.
Much of the material in “Oppenheimer: Science, Mission, Legacy” is based on rare materials and footage from the NSRC’s unclassified legacy collections. Narrated by NSRC Senior Historian Alan Carr, the film features in-depth interviews with:
- James Kunetka, author of “The General and the Genius: Groves and Oppenheimer – the Unlikely Partnership that Built the Atom Bomb”;
- Kai Bird, author of “American Prometheus: The Triumph and Tragedy of J. Robert Oppenheimer”; and
- Tim Rieser, the former U.S. Senate staffer who was instrumental in the Department of Energy’s December 2022 vacating of the Atomic Energy Commission’s 1954 revocation of Oppenheimer’s security clearance.
The documentary also includes footage of Secretary Granholm’s August 2023 visit to the Laboratory and an interview with J. Robert Oppenheimer’s grandson, Charles Oppenheimer. | physics |
http://codeschool.org/3d-projection-transcript/ | 2017-11-23T18:21:57 | s3://commoncrawl/crawl-data/CC-MAIN-2017-47/segments/1510934806856.86/warc/CC-MAIN-20171123180631-20171123200631-00496.warc.gz | 0.922151 | 5,579 | CC-MAIN-2017-47 | webtext-fineweb__CC-MAIN-2017-47__0__60234093 | en | 3D projection is the process of rendering numerically-described 3d geometry as a 2d image. In simple wire-frame rendering, this means transforming the 3d vertices of our objects into 2d coordinates–taking into account our chosen vantage point in the world–and then simply drawing straight lines between those coordinates. So to render a wire-frame cube for example, we transform the 8 3D vertices of its corners into 2D vertices, and in our image draw straight lines between those vertices. The trick, of course, is in how to do this transformation, taking into account the optics of cameras and the human eye, which cause distant points to converge to the center of the image. In other words, we must take into account the phenomenon of perspective.
In this video, I’ll explain why cameras and our eyes perceive the world in perspective and explain how to compute a perspective projection. We’ll also briefly discuss the simpler alternative, orthogonal projection, which is the style of rendering seen in architectural blueprints, where distant points do NOT converge to the center of the image.
In a later video, we’ll revisit how the projection computation is more commonly described using matrices. For now, though, we’ll stick to just simple algebra, geometry, and trigonometry.
In traditional photography, an image is formed by light striking a piece of light-sensitive film such that the different intensities and frequencies (aka colors) of light affect the different parts of the film surface differently. In digital photography, it’s the same idea, except instead of a surface of light-sensitive chemicals, we have a surface with a grid of sensors which each report a digital measure of the light striking them. These sensors are called CCD light sensors: charge-couple devices. (Light sensors are actually just one kind of CCD, but in the context of digital cameras, CCD usually implies a CCD light sensor.)
Now, to get an image from the world, what we cannot do is simply hold a film or light-sensor array in front of the scene, like shown here. We need the light from the respective parts of the scene to hit the corresponding parts of the surface, e.g. the light coming from the top of the scene–and only that light–should hit the top of the surface, and only the top of the surface. As depicted by the white lines here, the ray of light from the point at the top of the Eiffel tower should hit a point towards the top middle of our surface. What happens in the real world, however, is that light is bouncing all around, such that generally light from all parts of the scene hits all parts of the surface. Here we see some of the unwanted rays of light in red: light from all parts of the scene are hitting the same point on the surface, adding up to far too much light and probably not the right frequency. This happens for all points on the surface, such that we get a blank, all-white image. This is why cameras and the human eye have lenses: to focus the light from different parts of the scene onto different parts of the film or the sensor array.
The very simplest kind of lens is a pinhole lens, which is exactly what it sounds like. Punch a small hole in a box and you have a pinhole camera. As the diagram shows, light from a point at the top of the tree passes through the hole and only strikes a point at the bottom of the box’s interior; light from a point at the bottom of the tree passes through the hole and only strikes a point at the top. Effectively then, the image on the interior back surface gets mirrored upside down. This happens on the horizontal axis as well, at least from a person’s perspective standing behind the box: light from points on the left side of the tree end up on the right side of the box and light from points of the right side of the tree end up on the left side. (This isn’t actually depicted correctly in the diagram. Look closely at the smaller tree and you’ll see it hasn’t been correctly flipped horizontally.)
As you might imagine, a pinhole lens doesn’t produce a great image. Making the pinhole small tends not to allow in enough light, producing a weak image, but making the pinhole larger produces a blurry image: as the pinhole becomes larger, light from each point in the scene passes through the lens in a larger cone; these cones of light strike back interior of the camera, producing overlapping blotches of color instead of focused points.
Most practical cameras use a lens made up of one or more elements of glass. The idea is that the pieces of glass are shaped in such a way such that all light rays from one point in the scene get refracted to the proper point on the film. Here, all light rays from the same point in the scene that reach the front side of the lens are refracted onto the same point on the film. Notice that, like in a pinhole camera, the scene is getting flipped vertically and horizontally.
The proper distance from the lens to the film is called the focal length of the lens. If we moved the film closer to the lens, or if we moved it further away, the rays of light from one point in the scene wouldn’t converge onto the same point of the surface, producing a blurry image.
For detailed reasons of optics we won’t get into, a lens cannot perfectly focus points at all distances in the scene onto the image at once, producing an effect called ‘depth of field’, in which objects in the foreground and/or background may be blurry. With certain lenses and lighting conditions, points in a large range of distances can be nearly focused. Probably the most famous example of such shots are in Citizen Kane, such as this one where the woman in the foreground is in good focus but the men far behind her remain mostly in focus too.
Lenses with different focal lengths produce different images. Here we have a longer focal length top and a shorter focal length bottom. Because light through the long lens refracts at a shallower angle, fewer parts of the scene get focused onto the film, capturing a narrower portion of the scene. With the shorter angle lens, we get more of the scene onto the film. This is why shorter lenses are also known as wide angle lenses. (Somewhat confusingly, though, it’s not common to refer to a long focal length lens as a ‘narrow lens’, even though they do capture narrower portions of the scene.)
Now, consider an observer standing in a hall with a floor and ceiling that run parallel. Looking down the hall, the light rays from the floor and ceiling that reach the observer converge towards the same vertical part of the observer’s vision–in fact, if the hallway were long enough, the position of the distant parts of the floor and ceiling would be only imperceptibly different. This is perspective: light from the scene converges on the observer at a single point such that points further away in the scene converge towards the center of the image.
Now, with a simple, round lens, light converges directly towards the middle of the image, producing a curvilinear effect in which straight lines from the world may end up curved. More elaborate “rectilinear” lenses “correct” for this distortion by converging distant points separately along the X and Y axis instead of directly to the center. This preserves straight lines but at the cost of artificially stretching the image at the edges. In the example here, notice how much wider the rectilinear image is and notice how the wall panels on the left seem to get larger towards the left edge of the image even though those panels are all the same size.
Understand that the distortions of both curvilinear and rectilinear lenses become more apparent for wider angle lenses because, with a wider angle lens, points in the distance effectively converge faster to the center: an object which is a given distance from the lens converges more towards the center the wider the lens.
So now, the question is, which is more realistic, curvilinear or rectilinear? Well on the one hand, curvilinear perspective better preserves the relative sizes of objects, and it arguably better reflects an idealized perspective, in which light from a scene converges to a single point and so distant points converge directly towards the center. On the other hand, rectilinear simply looks right: to most people, rectilinear better matches human perception. Answering why this is the case quickly gets bogged down in the murky philosophy and science of perception, so we’ll just take it as given.
Getting to 3D rendering now, what we generally want to simulate is a rectilinear projection of a virtual world. In some advanced cases, we might strive to simulate aspects of real-world cameras or the human eye, such as depth of field or some degree of curvilinear bend. We’re just going to keep things simple, though, by ignoring such issues. What we’ll produce are perfectly rectilinear images with an infinite depth of field. This in fact, is basically the default case used in much 3D rendering, games especially.
If what we’re simulating isn’t necessarily a camera or human eye, we can think of our task this way: we have a virtual world and a virtual window in that world, and we want the 2D image which a virtual observer sees looking through that window. (Be clear that our observer is really neither a camera nor a pair of human eyes but instead just a point in space.) Anyway, the first thing to note in this setup is that the observer’s distance to the window changes the field of view: getting close to the window widens the field of view; backing away narrows the field of view. To determine what point from the scene should appear on a point of the image, we extrapolate a line from the observer through that point on the window until it collides with something in the scene. So, here, what the observer sees at the red dot on the window corresponds to a dark point on the tree; the color at that point on the tree is the color we want to see at the point on the image. Extrapolating like this through every point on the window gets us our image.
The question now is how to do this extrapolation from 3D coordinates.
Consider this process in just two dimensions, here from a side view. The line extrapolated through the window passes through a certain point on the window but hits the green apple at a higher point. In effect, this point of the scene gets translated down to where it should appear on the window; notably, where the apple closer along the line of extrapolation, it would require a smaller translation. Also note that the angle of the extrapolation line affects the size of the translation: the smaller the angle, the smaller the translation; once the angle is zero–that is, where the observer sees straight through the window–the translation is also zero. The point in the scene directly straight ahead never gets translated, no matter how close or far the point is.
For points that do need translation, however, the formula to find the point on the window is quite simple, derived by noting that the line of extrapolation forms two overlapping right triangles with the line extrapolated straight through the window. The value of a1 here, the distance from observer to window center, is our focal length, and up to us to select when rendering. Assuming then that we have the values a2 and b2, we can find b1 by noting that the ratio of b1 to a1 equals the ratio of b2 to a2 because these are corresponding sides of two right triangles of the same angle. Solving for b1, we get b1 equals a1 times the quantity b2 divided by a2. Assuming the window center to be our origin, then b1 is the height coordinate on the image of our point in the scene.
We can apply the exact same logic to find the point’s horizontal position on the image. The only change is that, this time, b1 and b2 are coordinates of our horizontal axis, so finding b1 gets us our horizontal coordinate.
Another way of thinking about this process is that we are squeezing the observer’s field of view into a rectangle such that all the points in our field of view get squeezed along with it: points farther back from the window and farther from the center axis get squeezed proportionally more. And, again, because we’re going for a rectilinear projection, we squeeze the vertical and horizontal axes separately, one before the other instead of at the same time (which would produce a curvilinear projection). So, here, this is what we end up with. Looking at the before and after side-by-side, note that the two red dots had the same distance from the center axis before the squeeze, but the red dot farther from the window gets squeezed more towards the center axis. Imagine then, that those two points described the side of a wall running parallel with the observer’s direction of vision. Once we account for projection, the wall seems to converge in the distance towards the observer’s center of vision. This is just like what we observe with our eyes or a camera: looking down these train tracks, the parallel lines of the rails converge to a point in the distance.
In any case, once we’ve squeezed all our vertices, we have their coordinates as they should appear on our 2D image. Assuming again that the window is the center of our coordinate system and that the horizontal axis is X, the vertical axis is Y, and the depth axis is Z, then the X Y coordinates of the vertices denote their position on the image. That is, assuming 0, 0 denotes the center of the image, which is actually often not the case. Recall from earlier units that 2D pixel coordinates are commonly described in terms of 0,0 at the top left corner with the Y axis pointing down. Also important, 0, 0 in a 2D image usually denotes the corner of the top-left pixel rather than its center. Moreover, we don’t necessarily want one world coordinate unit to have the same dimensions as a single pixel in our image. So to account for all of this, we must translate from our 3D XY coordinate system centered on the window to a 2D XY coordinate system which is possibly centered elsewhere and possibly of a different scale. It’s a simple translation we’ll come back to shortly.
Now, ideally, we’re modeling a field of view that’s shaped like a pyramid with its tip at the focal point, our so-called observer. Any object inside or overlapping this pyramid (here shown as a blue triangle from the side), should show up in our image.
So far, though, we’ve thought of our projection as capturing a virtual observer’s view through a virtual window, implicitly disregarding anything between the observer and the window. To render objects in front of the window, however, we can actually use the very same formula. Just like with objects behind the window, we can draw a line from the observer through an object on the near side, and where that line intersects the window represents where it should appear in the image. The only difference is that the object vertices end up expanding away from the center axis instead of contracting towards it.
Problems arise, however, when rendering objects very close to the focal point, for reasons having to do with floating-point rounding error and aspects of rendering which we’ll get into later. Briefly, imagine what happens in our formula as a2, the distance to the vertex, approaches zero: the smaller and smaller fraction may begin to exceed the limits of our floating-point precision, producing ugly errors, especially when we start drawing filled-in polygons. Even worse, a coordinate lying on the focal point would have an a2 value of zero, which in our formula would trigger a divide by zero and thus break the code. To avoid these issue, usual practice is to simply clip the drawn geometry with a Near Clipping Plane such that only geometry behind the plane gets rendered. Here, for example, this apple lies in the field of view but in front of the Near Clipping Plane, so we ignore it in our rendering.
For different reasons, it’s usual to also specify a Far Clipping Plane to cap rendering of objects past a certain distance. By rendering only objects within a certain distance, the rendering job can often be greatly simplified and hence made faster, which is of course especially important in games. Recent games often have the clipping distance set far enough away that it’s not noticeable in most scenes, but earlier 3D games often had to set it distractingly close, using distance fog to hide the appearance of distant objects popping in and out of the world. Again, modern games still use these techniques, but usually set the clipping and fog distance far enough away to be less noticeable.
By the way, the lopped-off pyramid formed by our truncated field of view is known as the frustum. (Make sure to get that correct: there’s no R after the T.)
Now, as a matter of convenience and simplification, it’s common to assume that the viewing plane corresponds with the Near Clipping Plane, that is, assume that it corresponds with the small end of our lopped-off pyramid. Does this mean we lose control of our focal length? Well yes, but no. Be clear that, within a field of view, changing the distance to the view plane doesn’t change the resulting image as long as the view plane changes size to fit the same field of view. So by fixing the view plane to coincide with the Near Clipping Plane instead of specifying them independently, we do lose direct control over the focal length, but we can set it indirectly by setting the field of view. Here, for example, the frustum on the right has a larger field of view and hence a shorter focal length.
Now, if the image plane and clipping plane are tied together, what if objects you want to see is getting clipped? How can we fix this without changing the apparent camera position and field of view? Well, we have two solutions. First, simply scale up the coordinates in your world such that everything is bigger and further apart. This would be as if the world outside your window grew but also moved away from the window such that everything through the window looks the same. Crucially, though, we scale the world relative to the focal point, not the origin at the center of the image plane. This way, some vertices may get moved onto the back side of the near-clipping-plane. Here, for example, one of the two points lies in front of the near clipping plane and so won’t get rendered. If we double the scale of the world, relative to the focal point, now both points get drawn, but we otherwise haven’t changed the image.
Alternatively, we can proportionally scale down the image plane and focal length, effectively moving the image plane closer to the focal point without changing the apparent image. This is certainly simpler, but as mentioned earlier, we should be cautious of letting the distance from the focal point to the Near Clipping Plane get too close to zero.
Anyway, let’s complete the process of rendering a wire-frame image. So again, we start by defining our camera to be facing up the z axis with our view plane centered on the origin. Having specified a focal length–i.e. the distance of the observer to the origin–we then perspective adjust each vertex in our scene.
For example, given a focal length of 20, the vertex at 5, 10, 30 gets adjusted with a1 equal to 20 and a2 equal to 20 plus 30. Computing for x, we plug in the x coord 5 as b2, giving us a new x coord 2. Computing for y, we plug in the y coord 10 as b2, giving us a new y coord 4. So this vertex gets perspective adjusted to coordinate 2, 4 on our view plane. Once we start filling in our polygons, we’ll have further use for the Z values, but in wire-frame rendering, we can ignore the Z values once we have our perspective adjusted vertices.
The last coordinate adjustment is to account for a possible difference between the image plane dimensions and the destination image dimensions. In other words, we must translate between view plane coordinates and pixel coordinates because 1 coordinate unit does not necessarily equal the width or height of 1 pixel. Here for example, if our view plane is 100 units wide and 70 units tall but our destination image is 200 pixels wide and 210 pixels tall–and assuming that our pixel coordinates system is centered at the center of the destination image–then a coordinate 20, 15 on the view plane gets translated to 40, 45 in pixel coordinates.
The formula is quite obvious: we observer that the ratio of the pixel x coordinate to the view plane x coordinate equals the ratio of the pixel grid width to the view plane width; likewise, the ratio of the pixel y coordinate to the view plane y coordinate equals the ratio of the pixel grid height to the view plane height. So solving for x of the pixel grid gets us x of the pixel grid equals x of the view plane times the pixel grid width divided by the view plane width. And solving for y of the pixel grid gets us y of the pixel grid equals y of the view plane times the pixel grid height divided by the view plane height.
The last complication is that the pixel grid origin is usually not at the center of the image but rather at the top left or sometimes the bottom left. When at the bottom left, we add half the pixel grid width to x and half the pixel grid height to y, which in this example would mean adding 100 and 105, yielding a coordinate 140, 150. When the origin is at the top left, we do the same thing but flip our y coordinate by subtracting everything from the pixel grid height, which in this example would mean subtracting 150 from 210, yielding a y coordinate 60.
Finally, once we have our pixel coordinates of the vertices, we get our wireframe rendering by simply drawing lines between the connected vertices. So here on the left, for example, the cube is made up of 8 vertices, and we simply draw lines between the vertices which define our edges. How exactly we keep track of which vertices connect to which is just a detail of how exactly we define our polygons in our data.
The only other thing to note here is that, were our projection meant to be curvilinear rather than rectilinear, we couldn’t simply draw straight lines between the vertices because we’d have to account for how straight lines should bend around the image center. A rectilinear projection spares us that problem.
Because this video already runs long, I’ll not go over actual code implementing this wire-frame rendering, but you’ll find running code examples on the site that build upon our previous 2D drawing code. There are only a couple hundred lines to it, actually, so it shouldn’t take much effort to read and understand.
Anyway, by now, we should understand how to render a 2D image from 3D geometry for the special case where our virtual camera view plane is at the origin of the world and the camera is looking up the Z axis. But what if we want to render the world from another angle and position? Well it turns out to be easiest not to move the camera in our virtual world but rather to move the world around the virtual camera. Whatever camera moves we want to make away from the origin, we get the same effect by actually moving everything in the world in the inverse direction. So for example, if we want to dolly this camera forward closer to the apple, we could instead just move the apple the same distance in the opposite direction. Likewise, instead of moving the camera up, we could just move the apple down the same distance. The same idea applies to rotations. If we want to pitch the camera down, pivoting around the origin, we could instead rotate every object in the world the same angle the opposite way, pivoting around the origin.
So now the question is, how do we move objects and rotate them? It’s an important question not just for moving our camera but also moving objects in our world relative to each other, and it’s something we’ll look at in detail when we talk about transformations.
Lastly here, recall that, for a given view plane size, longer focal lengths effectively narrow the field of view. Imagine, then, what happens as our focal length grows into infinity: the bounds of the field of view run parallel to the center axis of vision. What this mean is that when it comes time to squeeze our coordinates, none of them move at all: they’re already in their proper position for an infinite focal length. This special case is called an orthogonal projection, and it has the effect that lines running into the distance parallel with our vision never converge. Orthogonal projection is the sort of projection used in architectural blueprints because, while it makes object depth often difficult to interpret, it usefully cuts down on the number of visible lines in the image and preserves the relative distances between every point in the 2D plane.
You might assume orthogonal projection has no place in games, but most 2D games today are modeled as layers of flat images stacked in 3D space but rendered with an orthogonal projection. Here, for example, this scene is likely made up of a few layers of flat images: a couple layers of background depicting scenery at a few distances, then the foreground floors and walls that actually collide with the player, then the player avatar and the enemies, along with the gun projectile particle sprites and effects, and then a layer on top of the vines, plants, and other decorative objects. This layering not only makes it more straightforward to construct layered scenes, it allows 2D games to utilize the pixel-pushing power of the GPU.
The HUD elements are also likely drawn as layers of an orthogonal projection, but because they’re always rendered on top in fixed positions on the screen, they’re likely rendered in a separate coordinate system. This is in fact also how ‘proper’ 3D games render HUD elements: the 3D world is drawn with a perspective projection, then the HUD is drawn on top with a separate orthogonal projection. | physics |
http://www.draiggeoscience.com/geophysical-techniques/ground-penetrating-radar-gpr/ | 2019-06-16T16:32:52 | s3://commoncrawl/crawl-data/CC-MAIN-2019-26/segments/1560627998288.34/warc/CC-MAIN-20190616162745-20190616184745-00548.warc.gz | 0.854576 | 1,176 | CC-MAIN-2019-26 | webtext-fineweb__CC-MAIN-2019-26__0__72081733 | en | Ground Penetrating Radar (GPR)
The Earth’s magnetic field interacts with rock, or other subsurface materials, which causes variations in the Earth’s magnetic field received at the Earth’s surface. The magnetic susceptibility of the geology has a large influence on the induced magnetic field (i.e. a high-susceptibility body will produce a stronger induced field than a low susceptibility body).
The Ground Magnetics (Ground-mag) method measures the physical parameter described as the Total Magnetic Intensity (TMI) and this is measured in units of nano-Tesla (nT) using a magnetometer. Steel and other ferrous metals in the vicinity of a magnetometer can also distort the recorded data (so metal objects should be removed from clothing when recording). The strength of the TMI field is dependent on location (geographically) and varies with distance from the Earth’s centre (elevation) and with time. These factors are removed during the data processing phase. Reduction to the pole (RTP) is a transformation of the observed data with simulates the magnetic field distribution which could be observed if the inducing field were vertical (i.e. at the geomagnetic pole). The RTP transformation places magnetic highs directly over their causative bodies, and simplifies qualitative interpretation of data from moderate to low geomagnetic latitudes. The instabilities in the RTP process begin to become significant for geomagnetic latitudes <20 degrees, and generates strongest artefacts in the direction of magnetic declination (Rajagopalan, 2003). Further processing steps can also be performed on the data i.e. First Vertical Derivative (1VD), Analytical Signal (Ansig), to enhance the techniques visualisation of certain features. The processed magnetic maps (TMI, RTP) can be further modelled in 2D, by modelling the data response along a profile line with a geologic body of an inferred magnetic susceptibility. The model can be further refined with known drilling results and other available geophysical data. An example of a ground-mag contour map can be viewed in Figure 1.
Figure 1. An example image showing a GPR data cross-section with preliminary void/cavity and geological layer interpretation.
Ground-mag is a useful geophysical technology, especially in mineral exploration programmes. It is logistically straightforward to deploy, and provides detailed mapping of targeted zones very rapidly. Ground-mag is generally acquired on foot, but magnetic data can also be collected in an airborne (aero-mag) or marine environment (marine-mag).
Limitations of the ground-mag technique include:
- The magnetic method only responds to variations in the magnetic properties of the Earth
- Highly magnetic geologic or modern materials may obscure subtle features of interest
Ground-mag surveying could be used together with a complimentary geophysical technology (e.g. aero-mag, Gravity), conventional mapping, drilling, and indeed any other available source of information.
An advantage of Multichannel 3D GPR over conventional single channel GPR (2D GPR) is the area of investigation coverage. A swath of multiple GPR transmitter (Tx) and receiver (Rx) antennas are utilised in Multichannel 3D GPR investigations in comparison to standard GPR investigation which utilise a single channel Tx and Rx antenna. Figure 1 provides an example of potential GPR ray-paths between multiple transmitters and receivers for an example Multichannel 3D GPR set-up.
Figure 1. An example image illustrating multiple radar ray path combinations for a Multichannel 3D GPR set-up (Image source. Mala GPR, www.malagpr.com.au).
The 3D GPR data results produced from using Multichannel 3D GPR data are of a higher lateral resolution in comparison to reconstructing 3D GPR from multiple parallel 2D GPR profile data (see 3D GPR data comparison for the same depth interval in Figure 2). Note: The main limitation of GPR is that the depth of investigation is limited in the presence of electrically conductive materials (e.g. clay, saline groundwater).
Figure 2. An example image showing a comparison of a 3D GPR dataset created from a Multichannel 3D GPR data and multiple parallel 2D GPR data for the same depth interval (Image source. Mala GPR, www.malagpr.com.au).
The GPR method can be utilised to display subtle changes in the sub-surface of the ground or material of interest. Changes in material dielectric contrast can be caused by many factors including material deformation, such as cracking or contamination seepage. 3D regions of interest in the subsurface highlighted using the GPR method can be monitored over calendar time (4D monitoring) to determine if these regions are propagating, diminishing or showing no signs of change. This information can be particular useful to civil engineers or environmental scientists in reducing the risk of their ground, or material health monitoring assessments. An example illustrating the net volumetric changes in a GPR dataset monitoring a dense non-aqueous phase liquid (DNAPL) is shown Figure 1.
Figure 1. An example image illustrating the net volumetric changes of DNAPL seepage in the subsurface (image source: Birken, R. and Versteeg, R. (2000). “Use of four-dimensional ground penetrating radar and advanced visualization methods to determine subsurface fluid migration”. Journal of Applied Geophysics, 43 (2000), 215-226.)
for free consultation | physics |
https://imaginary.github.io/powergrid-dynamics-simulation/ | 2021-09-28T20:11:17 | s3://commoncrawl/crawl-data/CC-MAIN-2021-39/segments/1631780060882.17/warc/CC-MAIN-20210928184203-20210928214203-00420.warc.gz | 0.929095 | 559 | CC-MAIN-2021-39 | webtext-fineweb__CC-MAIN-2021-39__0__44114687 | en | Simulate local disturbances
Click on a node on the map to perturb its position and speed by these values.
What do I see?
This is a simulation of the Scandinavian high-voltage power transmission network. The links are transmission lines, they change their width proportional to their usage. The nodes are sites of power producers or consumers.
The nodes produce or consume AC power and behave as so-called oscillators.
Think of them as fast-running clocks which exchange their current time via the links. In stable operation of the power grid, all clocks are required to run at the same global speed, i.e. no clock is overturning another one. Speed deviations are visualised in the changing size of the nodes.
When the clock speed is the same at all nodes, the time differences between them are constant. Each of the nodes is its own time zone, with some being in advance and some being behind of the others. After each clock cycle, the positions are identified. Nodes that are behind draw power from advanced nodes. This determines the direction of power transmission.
The normal operation at the global clock speed with constant time differences is called synchronisation. In Europe, the nodes are synchronised at a global speed of 50Hz, i.e. clock cycles per minute. The larger the “time difference” between two nodes, the more power is being transmitted between them.
At a base speed of 50hz the clocks appear to stand still. By reducing the base speed, you reduce the slow-motion effect until you observe the real-time simulation.
Each clock is subject to a certain amount of friction when it deviates from the global speed. By increasing the friction multiplier, the power grid becomes more stable.
Experiments with disturbances
You can manually perturb the clock position and speed of any node by clicking on it. The size of the perturbation can be selected with the sliders on the left.
Alternatively, you can observe predefined perturbations at special nodes
node in appendices Here, it should be comparably easy to desynchronise a small group of nodes from the rest. A disturbance in an appendix is typically confined there.
hub (a node with many neighbours) The more neighbours a node has, the more likely are large speed deviations after a disturbance.
detour node (a node parallel to a direct connection) Here, it should be difficult to destabilise the power grid.
dense sprout (an end node connected to node with many neighbours) Perturbing a dense sprout can cause an interesting effect: A single node running at its own speed while the remaining network is in synchronisation. It is an effect predominantly affecting dense sprouts. | physics |
https://aai.solutions/oma-metal-ions-analyzer | 2023-12-05T05:03:27 | s3://commoncrawl/crawl-data/CC-MAIN-2023-50/segments/1700679100545.7/warc/CC-MAIN-20231205041842-20231205071842-00634.warc.gz | 0.781786 | 1,130 | CC-MAIN-2023-50 | webtext-fineweb__CC-MAIN-2023-50__0__219184687 | en | AAI’s metal ion analyzer continuously draws a liquid sample and outputs real-time concentrations of metal ions including copper, iron, nickel, chromium, and cobalt.
From mining to electroplating, a wide range of processes require online monitoring of metal ions in solution. The traditional lab method for measuring metal ions uses atomic absorption spectroscopy, which comes with slow results, expensive instrumentation, and human involvement.
The OMA system provides always-online analysis of trace-to-high metal ion concentrations at the site. This fully automated solution provides real-time response. The flexibility of full-spectrum analysis allows the user to add/ remove metal ion measurements or modify measurement ranges at any time.
To measure metal ions' concentrations, the OMA detects the distinctive absorbance curves of each measured metal and mathematically isolates this structure from the total sample absorbance. In accordance with Beer-Lambert Law, the OMA correlates the height of each curve directly to its corresponding real-time metal concentration.
All OMA models are equivalent in function and performance with identical electronic configurations. The models vary by form factor and materials of construction, each intended for a unique use case.
The OMA-300 is offered in two explosion-proof formats:
Eexp systems are purged and pressurized using a certified air-purging device. This method ensures that toxic/explosive gas is not allowed to accumulate inside the enclosure and is ideal when instrument air is available.
Eexd systems are contained within certified explosion-proof cast-aluminum enclosures. This method is more practical if the installation is remote or utilities are unreliable.
The OMA is built for direct analysis of the hot/wet sample, thus simplifying the scope of the sample system and retaining high sample integrity. From our vast experience in sampling design, we know that applications can be similar but are rarely identical. For this reason, we design and build sample conditioning systems on a project basis, working from the process to the drawing board.
Note: All performance specifications are subject to the assumption that the sample conditioning system and unit installation are approved by Applied Analytics. For any other arrangement, please inquire directly with Sales.
|Measurement Principle||Dispersive ultraviolet-visible (UV-Vis) absorbance spectrophotometry|
|Detector||nova II™ UV-Vis diode array spectrophotometer|
|Spectral Range||200-800 nm|
|Light Source||Pulsed xenon lamp (average 5 year lifespan)|
|Signal Transmission||600 μm core 1.8 meter fiber optic cables
Other lengths available
|Sample Conditioning||Custom design per application|
|Analyzer Calibration||If possible, analyzer is factory calibrated with certified calibration fluids; no re-calibration required after initial calibration; measurement normalized by Auto Zero|
|Reading Verification||Simple verification with samples and self-check diagnostic|
|Human Machine Interface||Industrial controller with touch-screen LCD display running ECLIPSE™ Software|
|Data Storage||Solid State Drive|
|Analyzer Environment||Indoor/Outdoor (no shelter required)|
|Ambient Temperature||Standard: 0 to 35 °C (32 to 95 °F)
Optional: -20 to 55 °C (-4 to 131 °F)
To avoid radiational heating, use of a sunshade is recommended for systems installed in direct sunlight.
|Sample Temperature||Standard: -20 to 70 °C (-4 to 158 °F)
Optional: up to 150 °C (302 °F) with cooling extensions
Contact AAI for temperatures above 150 °C (302°F)
|Sample Pressure||Using standard flow cell: 206 bar (3000 psi)
Using immersion probe: 100 bar (1470 psig)
|Electrical||85 to 264 VAC 47 to 63 Hz|
|Power Consumption||45 watts|
|Standard Outputs||1x galvanically isolated 4-20mA analog output per measured analyte(up to 3; additional available by upgrade)
2x digital outputs for fault and SCS control
|Optional Outputs||Modbus TCP/IP; RS-232; RS-485; Fieldbus; Profibus; HART;|
|Select analyzer type:||OMA-300 Wall-Mounted Analyzer|
|OMA-206P Portable Analyzer|
|OMA-406R Rackmount Analyzer|
|Response Time||1-5 seconds|
|Zero Drift||±0.1 % after 1hr warm-up, measured over 24hrs (constant ambient temperature)|
|Sensitivity||±0.1 % full scale|
|Noise||±0.004 AU at 220 nm|
Example ranges below. Custom ranges available.
|Cu2+||0-100 ppm: ±1 ppm|
|Ni2+||0-100 ppm: ±1 ppm|
|Fe2+||0-100 ppm: ±1 ppm|
|Cr6+||0-100 ppm: ±1 ppm|
|Co2+||0-100 ppm: ±1 ppm|
|Standard Design||General Purpose|
|Available Options||ATEX, IECEx, EAC, PESO|
|Please inquire with your sales representative for additional certifications (CSA, FM etc.).| | physics |
http://cqxftgjw.com/index.php/case/list/9 | 2020-09-29T15:50:31 | s3://commoncrawl/crawl-data/CC-MAIN-2020-40/segments/1600400202418.22/warc/CC-MAIN-20200929154729-20200929184729-00229.warc.gz | 0.951505 | 532 | CC-MAIN-2020-40 | webtext-fineweb__CC-MAIN-2020-40__0__47308867 | en | The waste heat power generation system is essentially similar to the thermal power generation system. Its main work principle is:
All kinds of fumes are produced in the production process of traditional building materials industry. This part of the flue gas has a lot of heat energy. In the past, it was usually discharged directly from the upper part of the chimney without any valuable utilization. The waste heat power generation system uses waste heat boiler to recover the heat energy in this part of the high temperature flue gas, to heat the water to superheated steam, and superheated steam to drive the turbine generator unit to run, thus generating electric energy to the high voltage power supply network of the factory, greatly reducing the amount of power purchased from factories and generating huge economic benefits.
Since 2001, our institute has carried out a lot of theoretical research on the utilization technology of waste heat resources of low temperature waste gas. It is considered that the low temperature waste heat recovery technology and the domestic low-temperature waste heat recovery equipment can fully utilize low-temperature waste heat resources such as cement, glass and other building materials industries, and are applied to power generation. Since then, with the practical application and construction of the project, the technology has been gradually improved and applied and promoted. The technology was successfully applied to cement production line in 2006, and was successfully applied to glass production line in 2007.
The low-temperature waste heat power generation project designed by our Institute of Jiangsu walrun Group Co., Ltd. is the first national glass factory to apply low-temperature waste heat power generation technology to actual projects. The project is also awarded the two prize of science and technology progress award of building materials science and Technology Award in 2009. In the same year, the People's Republic of China science and technology novelty report was issued by the Ministry of technology.
In 2009, the thermal power generation project of Chengdu Nan Bo Glass Co., Ltd., which was contracted by our institute, was put into operation and was praised by the owner. After the successful operation, the Ministry of industry and Commerce held a special promotion site to promote the whole industry.
At present, there are nearly more than 30 sets of glass waste heat power generation projects designed and contracted by our institute. Among them, several leading domestic enterprises in the domestic glass industry, such as Nan Bo, Xinyi, Qi Bin and Taiwan glass, have established long-term good cooperation. The more than 60 sets of cement waste heat power generation have created huge economic benefits for the owners, and have also made great contributions to China's environmental protection and energy saving industry. Offer. | physics |
https://www.loans.com.au/home-loans/types-of-solar-panels | 2024-04-12T18:25:44 | s3://commoncrawl/crawl-data/CC-MAIN-2024-18/segments/1712296816045.47/warc/CC-MAIN-20240412163227-20240412193227-00699.warc.gz | 0.934091 | 941 | CC-MAIN-2024-18 | webtext-fineweb__CC-MAIN-2024-18__0__179262670 | en | Different Types of Solar Panels
With the push well and truly on to shift away from fossil fuels to renewable energy sources, solar has become one of the most common means for Aussies to transition towards a cleaner future. In fact, figures from the Clean Energy Regulator revealed Australia is leading the world in rooftop solar installations.
If you are considering installing solar panels onto your new or existing home, there are a number of different types available depending on the intended use of the solar energy that is generated. We’ll look at these below to help determine which may be best suited to your home and intended use.
Types of solar panels
When it comes to navigating the solar panel market, there are typically three common types available, these are:
In Australia, both monocrystalline and polycrystalline makes are the most common, given they offer the best efficiency for both domestic and commercial use.
Monocrystalline solar panels
Monocrystalline panels are created from a single continuous crystal structure that is cut into several wafers. The panels are made from pure silicone and are typically identified by their dark blue or black appearance.
Monocrystalline panels are the most expensive of the three types, given they are made of pure silicone, yet are the most space and energy efficient efficient among all three solar panel types.
Polycrystalline solar panels
Polycrystalline panels are created from a number of different silicone crystals as opposed to a single continuous structure. To create the solar panel, silicone crystals are melted and poured into molds. As a result, polycrystalline solar panels are generally more affordable than monocrystalline panels since there is little wastage.
Despite being cheaper, polycrystalline solar panels have a lower heat tolerance, meaning they are less efficient in high-temperature environments.
Thin-film solar panels
Thin-film solar panels are created in a different manner to both mono and polycrystalline panels. Thin-film panels are made by spraying a layer of silicone onto a surface. Each panel does not require a frame backing, which makes them lighter and easier to install.
Thin-film solar panels are the cheapest of the three types, given they are typically portable and flexible, however are the least energy efficient.
Differences between monocrystalline and polycrystalline solar panels
As mentioned above, one of the key differences between the two most popular types of solar panels in Australia is how they are constructed. Mono meaning one, means the solar panels are made from a single continuous crystal structure. Poly on the other hand meaning multiple, means the solar panels are made from multiple different silicone crystals.
Monocrystalline panels typically have the highest efficiencies and power capacity. Monocrystalline solar panels can reach efficiencies higher than 20%, while polycrystalline solar panels will typically reach an efficiency of between 15 to 17%.
Monocrystalline solar panels tend to generate more power than other types of panels not only because of their efficiency but because they have come in higher wattage modules.
Monocrystalline and polycrystalline solar panels aren’t physically the same size, yet both types of solar panels tend to come in 60, 72 or 96 cell variants. However, even with the same number of cells, monocrystalline panels are capable of producing more electricity.
How to choose which solar panel is right for me?
Choosing a solar panel type will essentially come down to the specifics of your property, its intended use and your financial position. Monocrystalline, polycrystalline solar panels are typically the most reliable and energy efficient options, yet will set you back a greater cost than thin-film panels.
Property owners with plenty of rooftop space for solar panels can save money upfront by installing lower efficiency, lower-cost polycrystalline panels. However if you are looking to maximize your electric bill savings, you can do so by installing high-efficiency, monocrystalline solar panels.
About the article
As Australia's leading online lender, loans.com.au has been helping people into their dream homes and cars for more than 10 years. Our content is written and reviewed by experienced financial experts. The information we provide is general in nature and does not take into account your personal objectives or needs. If you'd like to chat to one of our lending specialists about a home or car loan, contact us on Live Chat or by calling 13 10 90. | physics |
https://controlbyweb.com/blog/understanding-dry-contacts-and-how-to-monitor-them/ | 2024-04-13T06:33:15 | s3://commoncrawl/crawl-data/CC-MAIN-2024-18/segments/1712296816586.79/warc/CC-MAIN-20240413051941-20240413081941-00595.warc.gz | 0.934773 | 711 | CC-MAIN-2024-18 | webtext-fineweb__CC-MAIN-2024-18__0__50206839 | en | A definition disclaimer: Like so much electronic terminology, “dry contact” has several synonyms and can have varying definitions and applications. Let’s break it down to its simplest form. By the end of this article, you’ll have a sense of why this distinction is useful, and why it’s true that you can use ControlByWeb relays to monitor any dry contact.
But First: Why Dry?
So, why are dry contacts considered “dry” in the first place? Because they’re not wet. (We know that doesn’t clear things up at all—keep reading!)
For years, electricity has been explained using water as an analogy of how electricity flows. It’s a natural comparison:
“The water/hose analogy for electricity is useful for explaining voltage, current, and power. In general terms, charge is water, voltage is the pressure of water, current is the flow of the water. Power is the total amount of water flowing in given time.” ‐ University of Washington’s Clean Energy Institute, Water Model of Electricity The analogy between water flow and electric flow helps explain the basic principles of electricity.
The Simple Definition
A dry contact is a contact that is isolated from a power source.
This means that, once a power source is wired to a dry contact, it becomes “wetted” and is now able to send a signal to a controller. Think of the comparison between an electric current and the flow of water—when it courses through the dry contact, it becomes “wet.”
Keep in mind that a dry contact has to be wetted for it to work; however, you can still define it as a dry contact if the power source comes from an external supply.
All of this is important as it helps to describe how a contact is wired. A wet contact, like a generator that has an integrated power supply, is easier to wire. A dry contact is simpler in nature but requires a power source to be run to the contact, making it more complex overall. However, in the realm of industrial low-voltage wiring, both are relatively easy to make work. (And it’s even easier when you have expert insight from the ControlByWeb sales and support team.)
How Our Controllers Work With Dry Contacts
Nearly all ControlByWeb programmable controllers have digital inputs that can monitor dry contact switches. A low voltage is sent through the input to know whether a contact is open (incomplete circuit) or closed (completed circuit). Different actions can be taken based on either open or closed states.
Common applications where our customers would use dry contacts include buttons, door sensors, alarm panels, and float switches. In the case of alarm panels, our device acts as a supervised input to send an alert to specified users when the alarm changes state (when the alarm “goes off”).
Float switches in are another common use case for dry contacts. For example: A customer has a tank with a pump and needs to know when the liquid reaches a certain level to turn on the pump. Inside the tank, a dry contact is placed on a float, and the float switch is set to a certain liquid level threshold. When it triggers, our controller sends a command to turn the pump motor on. This command can be sent remotely to another location using peer-to-peer communication. | physics |
https://dc.bentec.digital/high-density-cooling/ | 2023-12-03T03:43:11 | s3://commoncrawl/crawl-data/CC-MAIN-2023-50/segments/1700679100484.76/warc/CC-MAIN-20231203030948-20231203060948-00703.warc.gz | 0.931865 | 179 | CC-MAIN-2023-50 | webtext-fineweb__CC-MAIN-2023-50__0__171460919 | en | Rack Level High Density Cooling
(ITE) in high performance data
centers continues to drive the need for
more efficient and effective cooling technologies. Traditional air cooling is not a sustainable solution in these settings.
While liquid cooling offers far greater efficiencies than air cooling, many liquid cooling options require large capital expenditures, are difficult to integrate with existing infrastructure, and present complications when upgrades or added capacity are needed.
Because liquid is denser than air, it has much greater heat transfer capacity. The heat carrying capacity of water is 3,500 times higher than that of air.
Low-profile cold plates used in direct contact liquid cooling also have the advantage of taking up much less rack space than traditional heat sinks. While liquid cooling offers huge advantages in moving heat, managing the entire heat load of the rack with liquid cooling methods can be overly complex and cost prohibitive. | physics |
http://www.yaleclubmexico.org/texto_charlesbailyn.html | 2013-05-21T12:26:46 | s3://commoncrawl/crawl-data/CC-MAIN-2013-20/segments/1368699977678/warc/CC-MAIN-20130516102617-00096-ip-10-60-113-184.ec2.internal.warc.gz | 0.978081 | 276 | CC-MAIN-2013-20 | webtext-fineweb__CC-MAIN-2013-20__0__102158046 | en | Charles Bailyn is the Thomas E. Donnelley Professor of Astronomy and Physics at Yale University. He received his undergraduate degree from Yale and did graduate work at Cambridge University and Harvard University, receiving his Ph.D. from Harvard in 1987. His Ph.D. thesis on X-ray emitting binary stars received the Trumpler award for best North American Ph.D. thesis in astronomy. After three years as a member of Harvard's Society of Fellows, he returned to Yale as a faculty member in 1990, and has been there ever since. He is the author of over one hundred refereed research papers, focusing primarily on the observational study of black holes and related sources of X-rays, and on the study of dense star clusters and the consequences of collisions between stars. Professor Bailyn has carried out research with a wide variety of ground and space-based telescopes, and currently serves as the Principal Scientist of the Small and Moderate Aperture Research Telescope System (SMARTS) which operates four telescopes in Chile.
In addition to his research work, Professor Bailyn has developed innovative teaching methods in science courses for non-scientists, and has recently led a re-examination of all of Yale's courses of this kind. In 2004 he was awarded the Dylan Hixon Prize, Yale's highest honor for teaching excellence in the natural sciences. | physics |
http://beta.sestech.com/Product/Module/8 | 2018-09-22T15:20:28 | s3://commoncrawl/crawl-data/CC-MAIN-2018-39/segments/1537267158450.41/warc/CC-MAIN-20180922142831-20180922163231-00487.warc.gz | 0.879374 | 525 | CC-MAIN-2018-39 | webtext-fineweb__CC-MAIN-2018-39__0__10997452 | en | FFTSES is a Fast Fourier Transform computation module designed to help SES software users automate time domain transient analyses (lightning and other transient surges) based on frequency domain results obtained from the CDEGS computation modules MALZ, HIFREQ or SPLITS of the Right-of-Way (ROW) software package.
FFTSES converts the time domain input signal (from transients such as lightning or switching surges) into the frequency domain using the Fast Fourier Transform algorithm. Computations are performed in the frequency domain using CDEGS computation modules (MALZ, HIFREQ or SPLITS). Results such as electric fields, magnetic fields, scalar potentials, touch voltages, conductor potentials (GPR) and leakage currents are converted from the frequency domain back to the time domain based on selected frequencies, using the inverse Fast Fourier Transform algorithm. The process involves the sampling of the frequency spectrum, the selection of a minimum number of frequencies to be used by the computation modules, and related reporting and plotting functions, which are automated in FFTSES.
FFTSES automates all transformation steps from time-domain to frequency domain
When a transient current, such as a lightning surge, strikes a facility (e.g. a building, substation, tower, etc.), the following safety concerns often need to be addressed:
Excessive touch and step voltages, which may be dangerous to personnel standing near a grounding system.
Excessive electromagnetic fields within the substation, which can result in equipment damage.
Forward FFT mode:
Inverse FFT mode:
The built-in time domain transient analysis and error diagnosis algorithms will warn the user of any inappropriate input data.
The "Sample Selection of Frequency Spectrum" algorithm will automatically select a subset of frequency components out of the full spectrum, reducing the computation time of a transient analysis by a few orders of magnitude compared to the conventional "full spectrum frequency analysis". Time-consuming tasks such as modulation of the surge frequency spectrum by the system response in the inverse FFT operation are done automatically, further facilitating the user’s work.
The frequency domain data determined by the MALZ and HIFREQ computation modules is quickly collected, analyzed and displayed.
Data from other computation modules and similar sources (e.g. SPLITS of ROW) can also be studied.
The program analyzes the frequency domain response, searching in particular for possible resonances in the signal, and suggests appropriate frequencies for which further analysis is necessary to improve the accuracy of the results. | physics |
http://wattlab.nl/about-us | 2019-08-18T08:54:51 | s3://commoncrawl/crawl-data/CC-MAIN-2019-35/segments/1566027313747.38/warc/CC-MAIN-20190818083417-20190818105417-00275.warc.gz | 0.947742 | 696 | CC-MAIN-2019-35 | webtext-fineweb__CC-MAIN-2019-35__0__20086302 | en | With our roots in the Nuon Solar Team we're intrigued to know all about designing optimal solar power systems.
We're a young and energetic team that enjoys to bring design, technology and sustainability together.
Every one hour, enough sunlight touches the earth's surface to provide the energy we need during one year. For this reason we believe in a future where energy is generated everywhere around us and solar energy goes beyond the solar panels on roofs we are familiar with. By designing and producing tailor made solar solutions, we facilitate designers, engineers, architects and other makers to use the surface around us for solar energy. By collaborating with creators from different disciplines, we encounter a variety of challenging ideas. These ideas again push us to explore new applications of solar energy, each having their own requirements. This way we aim to open doors to new solar power applications and to accelerate the use of solar energy in the world around us.
Our roots lie in the Nuon Solar Team of the Delft University of Technology. This team has raced all over the world with their solar car Nuna. With nine World Championship titles in the last 15 years, the team can call themselves the most successful solar car racing team in the world.
Wattlab's founders David, Siebe en Bo were part of this team in 2015/2016. Together with their team they designed and manufactured the solar module for the Nuna 8s. On October 1st 2016, after 8 days of racing and more than 4700 kilometers, the team successfully defended their World Championship title and finished first!
During their time in the team they got really interested in solar technology. The dream to keep on innovating and to share knowledge about solar energy with the world slowly emerged. One year after, Wattlab was born and built the solar module for the Solar Team Eindhoven of 2017, which won the World Solar Challenge (Cruiser Class).
Wattlab was founded by Bo Salet, David Kester and Siebe Roefs. They met each other when they became part of the Nuon Solar Team. Sarah Arntz met Bo during their studies and she joined Wattlab from the moment we started working full-time and moved into our own work space. Our backgrounds can be found in Electrical Engineering, Applied Physics, Aerospace Engineering and Strategic Product Design. We are an energetic and committed team and all share a passion for projects where technology, innovation, art and sustainability come together.
In addition to the four of us, we're supported by a flexible team of technical students and researchers from the Delft University of Technology.
We are located in Rotterdam, where we have our own lab with production facilities. There we experiment and prototype to keep pushing the borders of renewable energy. We are located in De KROON, a new business area which is being transformed into a new Rotterdam hotspot where entrepreneurs can meet, strengthen and inspire each other. We are proud KROONers of the first hour and enjoy collaborating with our fellow KROONers.
De KROON is located on the border of Delfshaven, on the waterfront of de Maas river. It is the former site of Croonwolter & Dros and the electrotechnical history can still be noticed. With the develoment of solar energy systems we're continueing this electrotechnical ambiance - with an innovative, creative and sustainable touch. | physics |
https://italyworldsfairs.org/glossary/copper-metal | 2023-12-02T08:46:30 | s3://commoncrawl/crawl-data/CC-MAIN-2023-50/segments/1700679100381.14/warc/CC-MAIN-20231202073445-20231202103445-00654.warc.gz | 0.935274 | 205 | CC-MAIN-2023-50 | webtext-fineweb__CC-MAIN-2023-50__0__110555905 | en | Pure metallic element having the symbol Cu and atomic number 29; a reddish brown, ductile metal that is present in the earth's crust, occurring as a native metal and as ores of sulfide, sulfate and carbonate (azurite, malachite, etc.). It was the first metal used by humans, probably from about 8000 BCE, in the regions of Mesopotamia and India. By about 3800 BCE copper was made into bronze for weapons and knives. Today, copper is one of the most widely used metals because it has high electrical and thermal conductivity, can be easily fabricated, is ductile and polishes well. In moist air, copper forms a protective green film of basic carbonate. Metallic copper combines well with other metals to form alloys, most commonly brass and bronze. Copper and its alloys are used for wire, electrical devices, pipes, cooking vessels, ammunition, ornamental trim, roofing, grillwork, coins, musical instruments, jewelry, and sculptures. | physics |
https://www.amplifon.com/au/blog/human-hearing-range | 2024-04-20T01:29:00 | s3://commoncrawl/crawl-data/CC-MAIN-2024-18/segments/1712296817463.60/warc/CC-MAIN-20240419234422-20240420024422-00801.warc.gz | 0.944983 | 722 | CC-MAIN-2024-18 | webtext-fineweb__CC-MAIN-2024-18__0__162438087 | en | Remember that classic episode of Seinfeld where Jerry talks about hearing tests and super-human hearing?
It went something like this:
"Remember when you were in school and they'd do those hearing tests? And you'd really be listening hard, you know? I wanted to do unbelievable on the hearing test. I wanted them to come over to me after and go, "We think you may have something close to super-hearing. What you heard was a cotton ball touching a piece of felt. We're sending the results to Washington, we'd like you to meet the President."
Whilst hearing cotton ball touching felt might be a stretch, ever wondered whether your hearing falls within a ‘normal’ range?
Try the audio checks below and find out.
Due to the impact of continued exposure to loud noise over time, usually the younger we are, the better we hear. The ‘normal’ hearing frequency range of a healthy young person is about 20 to 20,000Hz. Though a ‘normal’ audible range for loudness is from 0 to 180dB, anything over 85dB is considered damaging, so we should try not to go there.
As we age, it’s the upper frequencies we lose first. So by the time we hit middle-age, we can expect to hear up to around 14,000Hz. Age related hearing loss (or presbycusis) naturally develops as we age and our hearing can begin to deteriorate as a result of external factors, including the environment and existing medical conditions.
Humans and animals hear by picking up on vibrations caused by sound waves in the air (or in some cases, the ground and water).
In the simplest terms, we ‘catch’ these vibrations in our middle-ear where they’re transferred into pressure waves. These waves are then passed through fluid into our inner-ear, or cochlea, where they’re translated into signals our brains can interpret.
The number of sound vibrations emitted per second is known as the frequency which is measured in hertz (Hz). The lower (or higher) the frequency, the lower (or higher) the pitch of the sound. The other consideration is loudness which is measured in decibels (dB).
Sounds with frequencies above the realms of human ears are called ultrasound and those below are called infrasound. Though we’re capable of distinguishing between 1400-odd pitches, most of the important speech-related sounds fall within a narrow, relatively low spectrum.
The highest note of human speech is a soprano singer’s C7 (around 2048Hz) and the lowest note is the C2 of a bass singer (around 64Hz). Though we can’t scream much above 3000Hz, US singer Tim Storms has sung a note at 0.189Hz. Ironically, no human will ever hear it, although it is possible to feel it.
Ever heard the hum of an alternating electrical current at night? That’s in the realm of 50 to 60Hz – not too far from the bottom of the human hearing range.
At the upper end, think dog whistles. To us they sound like a quiet hissing sound but to our canine friends it’s an air-raid siren.
Try these lower and upper sound frequency checkers to find out your audible range.
Let’s take a further look at common, everyday noises and where they sit on the decibel scale: | physics |
https://emefyduxeb.tk/phase-transitions-of-simple-systems.php | 2020-04-02T14:54:49 | s3://commoncrawl/crawl-data/CC-MAIN-2020-16/segments/1585370506988.10/warc/CC-MAIN-20200402143006-20200402173006-00250.warc.gz | 0.900478 | 5,794 | CC-MAIN-2020-16 | webtext-fineweb__CC-MAIN-2020-16__0__108980131 | en | The dynamics of the system is given by the rates at which a particle leaves a site m one can think of it as the topmost particle-see Fig. As our first example we assume it moves to the left nearest neighbour site m The hopping rates u n are a function of n the number of particles at the site of departure. The important attribute of the zero-range process is that it yields a steady state described by a product measure.
Here the normalisation Z M , L is introduced so that the sum of the probabilities for all configurations, with the correct number of particles L , is one. We shall explore later in Section the interesting possibilities afforded by the form 5. Note that f n is defined only up to a multiplicative constant and we could have included a factor z n in 6.
Later this factor reappears as a fugacity in Section.
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The proof of 5, 6 is, happily, straightforward. One simply considers the stationarity condition on the probability of a configuration probability current out of the configuration due to hops is equal to probability current into the configuration due to hops :. There exists an exact mapping from a zero-range process to an asymmetric exclusion process.
This is illustrated in Fig. The idea is to consider the particles of the zero-range process as the holes empty sites of the exclusion process. Then the sites of the zero-range process become the moving particles of the exclusion process. This is possible because of the preservation of the order of particles under the simple exclusion dynamics.
An interesting feature of the mapping is that it converts a model where the local degree of freedom can take unbounded values particle number in the zero-range process to a model where the local site variable is restricted to two values. On the other hand, a hopping rate u m which is dependent on m corresponds to a hopping rate in the exclusion process which depends on the gap to the particle in front.
So in principle the particles can feel each other's presence and it is possible to have a long-range interaction. We now show how the totally asymmetric, homogeneous zero-range process we have considered so far may be generalised yet retain steady states of a similar form to 5,6. First we consider an inhomogeneous system by which we mean the hopping rates are site dependent: the hopping rate out of site m when it contains n m particles is u m n m.
It is easy to check that the steady state is simply modified to. The proof is identical to that given above for the homogeneous case, with the trivial replacement of u n m by u m n m. A further generalisation is to the case of discrete time dynamics. This has been studied in in the context of a disordered asymmetric exclusion process. Here we translate the results into the zero-range process. Rather than processes occurring with a rate, time is counted in discrete steps and at each time step events occur with certain probabilities.
In the case of Parallel Dynamics , at each time-step all sites are updated. One particle from each site m is moved to the left, each with probability p m n m where n m is the number of particles at the site before the update. Note that the particles move simultaneously and particles do not move more than one site.
In this way one can interpolate between discrete time, parallel dynamics and continuous time dynamics. In ordered sequential updating schemes were also considered. These are discrete time updating schemes were one site is updated at a time, but the sites are updated in a fixed order.
The steady states for the forwards and backwards updating sequences were derived and it turns out they too have the form 11 with f m taking an expression related to the parallel case In the original paper paper of Spitzer some more general versions of the zero range process were considered. Here we discuss one interesting case which serves to generalise the totally asymmetric zero range process defined above to a process on a more general lattice or for any finite collection of points with a prescribed transition matrix for the dynamics of a single particle .
Thus the probability that in time dt a particle at m moves to n is. We assume that the transition matrix is irreducible i.
We now show that the steady state for the many-particle problem defined above is given by 11 where now f m n is given by. The proof is again a straightforward generalisation of that of Section. Equation 7 is modified to. Equating the terms m on each side of 18 , assuming 11 and cancelling common factors yields. Let us also discuss an example where the single particle problem has an inhomogeneous steady state. We consider a one-dimensional lattice where hops to the left and right neighbours are allowed but with probabilities that depend on the site.
Thus, we may write. The steady state of the single particle problem random walker on a disordered one dimensional lattice . This network is relevant to the disordered one-dimensional exclusion process studied in [61, 62, 63]. The sites in the present model correspond to the particles in the exclusion process which each have their own forward and backward hopping rates.
Another, particular instance of this network occurs in , where a repton model of gel electrophoresis is studied in the case of periodic boundary conditions see Section. An interesting consequence of the form of the steady state 17 is that it allows one to relate an arbitrary zero-range process to a model obeying detailed balance.
The idea is that if detailed balance doesn't hold, we can always define a new zero-range process to be denoted by a prime with the same steady state, but with a different dynamics obeying detailed balance. To do this, we solve the single particle problem 16 for the original model to obtain s m. It is easy to check from 17 that the new model has the same steady state as the original. Thus, within the realm of zero-range processes, to the steady state of any nonequilibrium model we can always identify a model satisfying detailed balance and therefore an energy function.
Of course, although the steady states are the same, there is no reason for the dynamical behaviour of the two systems to be related. To clarify this point we will discuss a simple example in Section. The marginals 17 have the interesting structure of being a product of a term s m n that depends on the nature of the network and a term involving the product of u n m which reflects the interactions at the site. The network can represent an arbitrary dimensional lattice or the effects of disorder, the only difficulty to surmount in obtaining the steady state is the solution of the single particle problem.
We now proceed to analyse the steady states of form 11 and the condensation transition that may occur. The important quantity to consider is the normalisation Z M , L as it plays the role of the partition sum.
Phase Transitions of Simple Systems
The normalisation is defined through the condition. The normalisation may be considered as the analogue of a canonical partition function of a thermodynamic system. Note that 30 tells us that the speed is independent of site and thus may be considered a conserved quantity in the steady state of the system. In the totally asymmetric system considered in Section III. More generally, however, the speed is not equal to the current and the fact that the speed is a conserved quantity is not a priori obvious. For example, in a system obeying detailed balance the net current is zero, but the speed as defined above remains finite.
The speed is a ratio of partition functions of different system sizes 30 and corresponds to a fugacity, as we shall see below. We will consider also the probability distribution of the number of particles at a site, taken here to be site 1. In general the probability distribution is site dependent but for a homogeneous system f m independent of m it will be the same for all sites. For large M , L 32 is dominated by the saddle point of the integral and the value of z at the saddle point is the fugacity.
The equation for the saddle point reduces to. We expect that for low f the saddle point is valid but, as we shall discuss, there exists a maximum value of z and if at this maximum value the rhs of 35 is finite, then for large f 35 cannot be satisfied. We now consider separately, and in more detail, how condensation may occur in the inhomogeneous and the homogeneous case.
In general, the inhomogeneous case i. Here we would just like to give an idea of how a condensation transition may occur by discussing a simple example.
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We then go on to analyse perhaps the simplest example of a condensation transition: a single inhomogeneous site . First we take the general model discussed in Section IV. For the moment we do not specify further the transition matrix; later we will discuss two specific examples one obeying detailed balance and one not.
Under these conditions f m is given by. Thus the ground state corresponds to the site with the lowest hopping rate. The normalisation Z M , L is equivalent to the canonical partition function of the Bose gas. Interpreting u as a density of states, equation 39 corresponds to the condition that in the grand canonical ensemble of an ideal Bose gas the number Bosons per state is f. The theory of Bose condensation tells us that when certain conditions on the density of low energy states pertain we can have a condensation transition.
Then 35 can no longer be satisfied and we have a condensation of particles into the ground state, which is here the site with the slowest hopping rate. This case is discussed further, in the context of an asymmetric exclusion process on an infinite system, by J. Krug in this volume . It is easy to see that 11 simplifies to. In this case the normalisation Z M , L is easy to calculate combinatorially:. In the low density phase 42 the particles are evenly spread between all sites and we will refer to it as the homogeneous phase. We now discuss two models which both have this steady state: a driven system and a system obeying detailed balance.
This provides an illustration of the idea discussed in Section IV. First we take the totally asymmetric model so that particles move to the site to the left: the transition matrix is. So this model is similar to that discussed in Section III. The equivalent exclusion process is illustrated in Fig. We see that the equivalent exclusion process is system of hard-core particles hopping to the right, one particle being slower than the rest. The interpretation of the two phases within the context of the exclusion process is that in the condensed phase for the exclusion process a low density of particles a 'traffic jam' forms behind the slow particle and the slow particle has a finite fraction of the lattice as 'empty road' ahead.
Whereas in the homogeneous phase a high density of particle for the exclusion process the particles are roughly evenly spaced. On the other hand one may consider the case where the one particle problem is a symmetric random walk so that the system obeys detailed balance. The transition matrix is given by. When we map this system to a simple exclusion process we see from Fig.
In the condensed phase the gap between these particles diverges. Previously a single asymmetric particle in a sea of symmetric particles has been studied but in that case there is no phase transition. At first it seems that we have found a counterexample to the received wisdom that no phase transition should occur in an equilibrium system, since we have a condensation transition in a model with local dynamics obeying detailed balance.
Inferring an energy function from the steady state 40 through the following equation. Therefore the energy is 'unphysical' in that it has very long range interactions. Thus the phase transition can be rationalised within the categories of exceptions discussed in Section II.
We have seen that this simplest example of a condensation transition a single inhomogeneous site in the zero range process is exhibited both in a driven model and also in a model obeying detailed balance but with long-range energy function. Again it should be stressed that although the steady states of these two models are equivalent, the dynamical properties should be very different. However in the homogeneous phase of the model obeying detailed balance we expect symmetric exclusion like behaviour and the dynamic exponent to be 2 implying relaxation times of M 2 .
A similar analysis has been carried out in the context of balls-in-boxes and branched polymer models . The fugacity z must be chosen so that F converges or else we could not have performed From 33 we see that b is the limiting value value of the u m i. We interpret 35 as giving a relation between the density of holes number of holes per site and the fugacity z.
The saddle point condition 35 becomes. Given that the rhs of 45 is a monotonically increasing function of z which is not difficult to prove we deduce that density of particle increases with fugacity. Physically, the condensation would correspond to a spontaneous symmetry breaking where one of the sites is spontaneously selected to hold a finite fraction of the particles.
Thus, for condensation to occur i. We now assume that u n decreases uniformly to b in the large n limit as. Analysis of the series. Therefore the 'no phase transition rule' does not apply. One also gains insight by translating the results into the language of the simple exclusion process. Having discussed the case where a true phase transition occurs we now consider a homogeneous example where, although there is no strict condensation transition, some interesting crossover phenomena occur . One can interpret these hop rates as meaning that a site only distinguishes whether it contains greater than r particles.
When we use the mapping of Section III. In fact these phases correspond exactly to those of the single defect problem discussed in the previous subsection 42, 43 with b playing the role of p. For finite r , z is actually a smoothly increasing function of f but we see from 55, 57 that the curve sharpens as r increases. One sees a dramatic sharpening as r increases leading to a sharp crossover between a low density and high density regime. In order to see the effects of this sharp crossover it is interesting to consider the particle number probability distribution 31 which for this system is site independent and given by.
Therefore to simulate the model one requires a number of particles very much larger than this! If care is not taken to do this, and the total number of particles in the system is comparable to the typical occupancy, one would have an apparent condensate on a finite system. An example of this phenomenon was studied recently within the context of a 'bus route model' .
There the underlying motivation was to consider how a non-conserved quantity could mediate an effective long-range interaction amongst a conserved quantity in a driven system with a strictly local dynamical rule. The model considered was defined on a 1 d lattice. Each site bus-stop is either empty, contains a bus a conserved particle or contains a passenger non-conserved quantity.
The dynamical processes are that passengers arrive at an empty site with rate l ; a bus moves forward to the next stop with rate 1 if that stop is empty; if the next stop contains passengers the bus moves forward with rate b and removes the passengers. Since the buses are conserved, there is a well defined steady state average speed v. This fact can be used to integrate out the non-conserved quantity passengers within a mean-field approximation.
From this probability an effective hopping rate for a bus into a gap of size n is obtained by averaging the two possible hop rates 1, b :. We can now see that this mean-field approximation to the bus-route model is equivalent to a homogeneous zero-range process as discussed earlier in this section.
It is reasonable to believe that the system behaves in a similar way to the system with a finite 'range' r discussed in Section V. In the bus route problem this corresponds to the universally irritating situation of all the buses on the route arriving at once.
As mentioned earlier the zero-range process and related models have appeared several times in the modelling of nonequilibrium phenomena. Here we briefly discuss a few of these instances to illustrate the ubiquity of the basic model. In models of sandpile dynamics are considered. A zero range process is used to model the toppling of sand on a one-dimensional lattice; specifically the system is homogeneous and the occupation number of a site becomes the height of sand h at that site. This limit means that a particle grain of sand keeps moving until it finds an unoccupied site, thus a hopping event may play the role of an avalanche.
Although in terms of sandpiles and self-organised criticality this model is rather trivial, it did serve to investigate the idea of a diverging diffusion constant. In a different context Barma and Ramaswamy introduced the 'drop-push' model of activated flow involving transport through a series of traps. Each trap can only hold a finite number of particles. For the trap depth set equal to one this model is essentially the same as the sandpile model of discussed above i. A generalisation to inhomogeneous traps, and partially asymmetric hopping rates dependent on the occupancy of the trap was made in and a steady state similar to 11, 17 demonstrated.
The interface can be visualised as an ascending staircase of terraces. Adatoms land on the terraces and diffuse until they bind to the ascending step. If the ratio of deposition rates over diffusion rates tends to zero then the resulting dynamics is that a terrace shrinks by one unit and the adjacent higher terrace grows by one unit with a rate proportional to the size of the terrace. Thus the terrace lengths are equivalent to the site occupancies of an asymmetric zero-range process that was discussed in Section III.
The equivalence of zero range processes to a general class of step flow models is discussed in . Finally we note that the repton model of gel-electrophoresis studied in the case of periodic boundary conditions by is equivalent to an inhomogeneous zero-range process. In this case, the particles of the zero-range process represent the excess stored length of a polymer which diffuses along the tube of the polymer. The sites in the zero-range process represent the segments of the polymer tube and the inhomogeneities in site hopping rates reflect the shape of the polymer tube.
In this work the aims were to give an overview of the area of phase transitions and ordering in one-dimensional systems and also to analyse in some detail a particularly simple model, the zero-range process. In Section II several features were identified which could lead to the anomalous behaviour of ordering and phase transitions in equilibrium systems: long-range interactions; zero temperature; unbounded local variable. For nonequilibrium systems some concepts which may be important emerged: conserved order parameter; drive; forbidden microscopic transitions.
The simplicity of the zero-range process allowed us to analyse the steady state of the model in detail. We then analysed the condensation transitions that can occur. On an inhomogeneous system the condensation is very reminiscent of Bose-Einstein condensation. For it to occur requires certain conditions to hold on the distribution of hopping rates. In the homogeneous system the condensation corresponds to a spontaneous symmetry breaking, since an arbitrary site is selected to hold the condensate.
The condition for it to occur is that the hopping rate dependence on the site occupancy decays sufficiently slowly. It was also shown that when the condition for condensation does not hold, one can still observe very sharp crossover behaviour and apparent condensation on a finite system. An interesting possibility that was explored was that of the existence of an effective energy function. Dirk V. Despite using different formalizations and investigating very different kinds of systems, the same unimodal dependence between disorder and complexity has been found in several independently conducted studies.
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Phase transition - Wikipedia
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- Phase transitions in one-dimensional nonequilibrium systems?
- Kids Need...: Parenting Cards for Families and the People Who Work With Them.
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https://www.topnotchyachts.ca/keeping-the-waves-at-bay/ | 2023-12-03T18:21:07 | s3://commoncrawl/crawl-data/CC-MAIN-2023-50/segments/1700679100508.42/warc/CC-MAIN-20231203161435-20231203191435-00291.warc.gz | 0.913774 | 703 | CC-MAIN-2023-50 | webtext-fineweb__CC-MAIN-2023-50__0__239653343 | en | Picture yourself gliding through serene waters on a luxurious yacht, the gentle breeze kissing your face as you soak in the stunning surroundings. But wait! What about those annoying waves that can turn your dreamy voyage into a rocky rollercoaster ride? That’s where yacht stabilizers come to the rescue. In this blog, we’ll explore everything you need to know about these remarkable devices that keep your yacht steady and your journey smooth. So, hop aboard as we embark on this stabilizing adventure!
What are Yacht Stabilizers?
Yacht stabilizers are sophisticated systems designed to reduce the rolling motion of a yacht caused by waves or external factors. By counteracting the forces that make a yacht sway from side to side, these stabilizers significantly improve onboard comfort, allowing passengers and crew to enjoy a more stable and pleasant experience at sea.
Types of Yacht Stabilizers:
- Active Stabilizers: These stabilizers utilize advanced technology, such as gyroscopes and hydraulic systems, to actively counteract the rolling motion of the yacht. They continuously monitor the vessel’s movement and adjust the stabilizing fins or appendages accordingly. This real-time adjustment helps maintain a smooth and steady ride.
- Passive Stabilizers: Unlike active stabilizers, passive stabilizers rely on fixed fins or other appendages installed on the yacht’s hull. These fins use hydrodynamic principles to reduce rolling motion. While not as adaptable as active stabilizers, they are still effective in stabilizing the yacht and are generally more cost-effective.
How Do Yacht Stabilizers Work?
Yacht stabilizers work on the principle of Newton’s laws of motion. When a wave hits a yacht, it creates a force that attempts to tip the vessel to one side. Stabilizers counteract this force by creating an opposing force in the opposite direction, helping the yacht maintain a more level position. By using either active or passive stabilization methods, these systems help dampen the rolling motion, ensuring a smoother journey for everyone on board.
Did you know that yacht stabilizers were initially inspired by aircraft technology? The concept of using wings or fins to stabilize an aircraft in flight was adapted for maritime use, revolutionizing the yachting industry and enhancing onboard comfort for countless enthusiasts.
Benefits of Yacht Stabilizers:
- Enhanced Comfort: By minimizing the rolling motion, stabilizers reduce seasickness and provide a more comfortable experience for passengers and crew, allowing them to fully enjoy their time on the yacht.
- Safety and Stability: Stabilizers increase the overall stability of the yacht, reducing the risk of accidents and improving safety during rough weather conditions.
- Protection of Onboard Equipment: The reduced motion provided by stabilizers helps protect delicate equipment, furnishings, and artwork on board, minimizing the risk of damage.
- Improved Fuel Efficiency: Yacht stabilizers can also contribute to better fuel efficiency by reducing the drag caused by excessive rolling motion. This can result in significant cost savings over time.
Yacht stabilizers are indispensable devices for any yacht owner or enthusiast looking to maximize comfort and stability while cruising the seas. Whether you opt for active or passive stabilizers, these innovative systems ensure a smoother sailing experience, providing protection, comfort, and safety on board. So, next time you embark on a luxury yachting adventure, let the stabilizers work their magic and keep the waves at bay! | physics |
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