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Thiele Tube
The Thiele tube, named after the German chemist Johannes Thiele, is a laboratory glassware designed to contain and heat an oil bath. Such a setup is commonly used in the determination of the melting point of a substance. The apparatus resembles a glass test tube with an attached handle. Operation Oil is poured into the tube, and then the "handle" is heated, either by a small flame or some other heating element. The shape of the Thiele tube allows for formation of convection currents in the oil when it is heated. These currents maintain a fairly uniform temperature distribution throughout the oil in the tube. The side arm of the tube is designed to generate these convection currents and thus transfer the heat from the flame evenly and rapidly throughout the heating oil. The sample, packed in a capillary tube, is attached to the thermometer, and held by means of a rubber band or a small slice of rubber tubing. The Thiele tube is usually heated using a microburner ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thiele Tube V3
Thiele is a German-language surname. Geographical distribution As of 2014, 78.0% of all known bearers of the surname ''Thiele'' were residents of Germany, 10.9% of the United States, 2.3% of Australia, 2.0% of Brazil, 1.0% of Canada and 1.0% of South Africa. In Germany, the frequency of the surname was higher than national average (1:1,741) in the following states: * 1. Brandenburg (1:477) * 2. Saxony-Anhalt (1:522) * 3. Saxony (1:624) * 4. Bremen (state), Bremen (1:1,058) * 5. Thuringia (1:1,132) * 6. Lower Saxony (1:1,241) * 7. Hamburg (1:1,465) * 8. Mecklenburg-Vorpommern (1:1,689) * 9. Berlin (1:1,708) People * Alfonso Thiele (1922–1986), American Italian racing driver * Allen Thiele (1940–2017), Master Chief Petty Officer of the Coast Guard * Annekatrin Thiele (born 1984), German rower * Arthur Thiele (1860–1936), German illustrator * August Thiele (1894–1967), Vizeadmiral with the Kriegsmarine * Aurelie Thiele, French professor using optimization algorithms to contro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thiele Tube
The Thiele tube, named after the German chemist Johannes Thiele, is a laboratory glassware designed to contain and heat an oil bath. Such a setup is commonly used in the determination of the melting point of a substance. The apparatus resembles a glass test tube with an attached handle. Operation Oil is poured into the tube, and then the "handle" is heated, either by a small flame or some other heating element. The shape of the Thiele tube allows for formation of convection currents in the oil when it is heated. These currents maintain a fairly uniform temperature distribution throughout the oil in the tube. The side arm of the tube is designed to generate these convection currents and thus transfer the heat from the flame evenly and rapidly throughout the heating oil. The sample, packed in a capillary tube, is attached to the thermometer, and held by means of a rubber band or a small slice of rubber tubing. The Thiele tube is usually heated using a microburner ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Johannes Thiele (chemist)
Friedrich Karl Johannes Thiele (May 13, 1865 – April 17, 1918) was a Germans, German chemist and a prominent professor at several universities, including those in Munich and Strasbourg. He developed many laboratory techniques related to isolation of organic compounds. In 1907 he described a device for the accurate determination of melting points, since named Thiele tube after him. Thiele was born in Ratibor, Prussia, now Racibórz, Poland. Thiele studied mathematics at the University of Breslau but later turned to chemistry, receiving his doctorate from University of Halle-Wittenberg, Halle in 1890 . He taught at the University of Munich from 1893 to 1902, when he was appointed professor of chemistry at Strasbourg. He developed the preparation of glyoxal bis(guanylhydrazone). After Friedrich August Kekulé von Stradonitz, Kekulé's proposal for Aromaticity, benzene structure in 1865, Thiele suggested a "Partial Valence Hypothesis", which concerned Covalent bond, double a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laboratory Glassware
Laboratory glassware refers to a variety of equipment used in scientific work, and traditionally made of glass. Glass can be blown, bent, cut, molded, and formed into many sizes and shapes, and is therefore common in chemistry, biology, and analytical laboratories. Many laboratories have training programs to demonstrate how glassware is used and to alert first–time users to the safety hazards involved with using glassware. History Ancient era The history of glassware dates back to the Phoenicians who fused obsidian together in campfires making the first glassware. Glassware evolved as other ancient civilizations including the Syrians, Egyptians, and Romans refined the art of glassmaking. Mary the Jewess, an alchemist in Alexandria during the 1st century AD, is credited for the creation of some of the first glassware for chemical such as the ''kerotakis'' which was used for the collection of fumes from a heated material. Despite these creations, glassware for chemical us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heat
In thermodynamics, heat is defined as the form of energy crossing the boundary of a thermodynamic system by virtue of a temperature difference across the boundary. A thermodynamic system does not ''contain'' heat. Nevertheless, the term is also often used to refer to the thermal energy contained in a system as a component of its internal energy and that is reflected in the temperature of the system. For both uses of the term, heat is a form of energy. An example of formal vs. informal usage may be obtained from the right-hand photo, in which the metal bar is "conducting heat" from its hot end to its cold end, but if the metal bar is considered a thermodynamic system, then the energy flowing within the metal bar is called internal energy, not heat. The hot metal bar is also transferring heat to its surroundings, a correct statement for both the strict and loose meanings of ''heat''. Another example of informal usage is the term '' heat content'', used despite the fact that p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oil Bath
An oil bath is a type of heated bath used in a laboratory, most commonly used to heat up chemical reactions. It's essentially a container of oil that is heated by a hot plate or (in rare cases) a Bunsen burner. Use These baths are commonly used to heat reaction mixtures more evenly than would be possible with a hot plate alone, as the entire outside of the reaction flask is heated. Generally, silicone oil is used in modern oil baths, although mineral oil, cottonseed oil and even phosphoric acid have been used in the past. Hazards Overheating the oil bath can result in a fire hazard, especially if mineral oil is being used. Generally, the maximum safe operating temperature of a mineral oil bath is approximately , the oil's flash point. Mineral oil can't be used above due to the compound's boiling point. If higher temperatures are needed, a silicone oil or a sand bath may be used instead. Silicone oil baths are effective in the 25 °C (77 °F) - 230 °C (446 °F) range. Sand b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melting Point
The melting point (or, rarely, liquefaction point) of a substance is the temperature at which it changes state from solid to liquid. At the melting point the solid and liquid phase exist in equilibrium. The melting point of a substance depends on pressure and is usually specified at a standard pressure such as 1 atmosphere or 100 kPa. When considered as the temperature of the reverse change from liquid to solid, it is referred to as the freezing point or crystallization point. Because of the ability of substances to supercool, the freezing point can easily appear to be below its actual value. When the "characteristic freezing point" of a substance is determined, in fact, the actual methodology is almost always "the principle of observing the disappearance rather than the formation of ice, that is, the melting point." Examples For most substances, melting and freezing points are approximately equal. For example, the melting point ''and'' freezing point of mercury is . How ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Substance
A chemical substance is a form of matter having constant chemical composition and characteristic properties. Some references add that chemical substance cannot be separated into its constituent elements by physical separation methods, i.e., without breaking chemical bonds. Chemical substances can be simple substances (substances consisting of a single chemical element), chemical compounds, or alloys. Chemical substances are often called 'pure' to set them apart from mixtures. A common example of a chemical substance is pure water; it has the same properties and the same ratio of hydrogen to oxygen whether it is isolated from a river or made in a laboratory. Other chemical substances commonly encountered in pure form are diamond (carbon), gold, table salt (sodium chloride) and refined sugar (sucrose). However, in practice, no substance is entirely pure, and chemical purity is specified according to the intended use of the chemical. Chemical substances exist as solids, liquids, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Test Tube
A test tube, also known as a culture tube or sample tube, is a common piece of laboratory glassware consisting of a finger-like length of glass or clear plastic tubing, open at the top and closed at the bottom. Test tubes are usually placed in special-purpose test tube rack, racks. Types and usage Chemistry Test tubes intended for general chemical work are usually made of glass, for its relative resistance to heat. Tubes made from expansion-resistant glasses, mostly borosilicate glass or fused quartz, can withstand high temperatures up to several hundred degrees Celsius. Chemistry tubes are available in a multitude of lengths and widths, typically from 10 to 20 mm wide and 50 to 200 mm long. The top often features a flared lip to aid pouring out the contents. A chemistry test tube typically has a flat bottom, a round bottom, or a conical bottom. Some test tubes are made to accept a ground glass joint, ground glass stopper or a screw cap. They are often provided w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Convection
Convection is single or multiphase fluid flow that occurs spontaneously due to the combined effects of material property heterogeneity and body forces on a fluid, most commonly density and gravity (see buoyancy). When the cause of the convection is unspecified, convection due to the effects of thermal expansion and buoyancy can be assumed. Convection may also take place in soft solids or mixtures where particles can flow. Convective flow may be transient (such as when a multiphase mixture of oil and water separates) or steady state (see Convection cell). The convection may be due to gravitational, electromagnetic or fictitious body forces. Heat transfer by natural convection plays a role in the structure of Earth's atmosphere, its oceans, and its mantle. Discrete convective cells in the atmosphere can be identified by clouds, with stronger convection resulting in thunderstorms. Natural convection also plays a role in stellar physics. Convection is often categorised or d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermometer
A thermometer is a device that temperature measurement, measures temperature or a temperature gradient (the degree of hotness or coldness of an object). A thermometer has two important elements: (1) a temperature sensor (e.g. the bulb of a mercury-in-glass thermometer or the pyrometric sensor in an infrared thermometer) in which some change occurs with a change in temperature; and (2) some means of converting this change into a numerical value (e.g. the visible scale that is marked on a mercury-in-glass thermometer or the digital readout on an infrared model). Thermometers are widely used in technology and industry to monitor processes, in meteorology, in medicine, and in scientific research. History While an individual thermometer is able to measure degrees of hotness, the readings on two thermometers cannot be compared unless they conform to an agreed scale. Today there is an absolute thermodynamic temperature scale. Internationally agreed temperature scales are designed to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Calgary
The University of Calgary (U of C or UCalgary) is a public research university located in Calgary, Alberta, Canada. The University of Calgary started in 1944 as the Calgary branch of the University of Alberta, founded in 1908, prior to being instituted into a separate, autonomous university in 1966. It is composed of 14 faculties and over 85 research institutes and centres. The main campus is located in the northwest quadrant of the city near the Bow River and a smaller south campus is located in the city centre. The main campus houses most of the research facilities and works with provincial and federal research and regulatory agencies, several of which are housed next to the campus such as the Geological Survey of Canada. The main campus covers approximately . A member of the U15, the University of Calgary is also one of Canada's top research universities (based on the number of Canada Research Chairs). The university has a sponsored research revenue of $380.4 million, wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
