any free neutron (one that is not bound within an atomic nucleus) that has an average energy of motion (kinetic energy) corresponding to the average energy of the particles of ...
(from the article "Nyquist, Harry") In 1927 Nyquist provided a mathematical explanation of the unexpectedly strong thermal noise studied by J.B. Johnson. The understanding of noise is of critical importance for communications systems. Thermal noise ...
(from the article "integrated circuit") Two more chemical methods of deposition are electrodeposition (or electroplating) and thermal oxidation. In the former the substrate is given an electrically conducting coating and placed in a liquid solution ...
(from the article "whirlwind") ...layers of the atmosphere. This energy is absorbed by the atmosphere to produce a highly unstable layer near the ground. Release of the energy stored in this unstable layer leads ...
(from the article "river") ...facilities, including nuclear power plants, steel mills, chemical-processing facilities, and oil refineries, use large quantities of water for cooling and return it at elevated temperatures. Such heated water can alter ...
(from the article "Spain") Thermal power plants, located near coal fields or ports that receive imported oil, supply about half of Spain's electricity needs. The country also relies heavily on hydroelectric power, mainly provided ...
(from the article "food preservation") Thermal processing is defined as the combination of temperature and time required to eliminate a desired number of microorganisms from a food product.
process by which energy, in the form of electromagnetic radiation, is emitted by a heated surface in all directions and travels directly to its point of absorption at the speed ... [6 Related Articles]
(from the article "asteroid") The most widely used technique for determining the sizes of asteroids (and other small bodies in the solar system) is that of thermal radiometry. This technique exploits the fact that ...
(from the article "nuclear engineering") Nearly all commercial nuclear reactors in operation or under construction are thermal reactors. They are called thermal reactors because their fuel is fissioned by neutrons that have been slowed down ...
(from the article "petroleum refining") The most widespread process for rearranging hydrocarbon molecules is naphtha reforming. The initial process, thermal reforming, was developed in the late 1920s. Thermal reforming employed temperatures of 510°-565° C (950°-1,050° ...
(from the article "thermodynamics") ...but the temperature of a large body of water such as the Atlantic Ocean does not materially change if a small amount of heat is withdrawn to run a heat ...
(from the article "refractory") ...corrosive molten materials and gases. In addition to temperature and corrosion resistance, refractories must possess superior physical wear or abrasion resistance, and they also must be resistant to thermal shock. ...
(from the article "radiation") ...a struck, recoiling surface atom undergoes a random sequence of elastic scatterings in the target material, ultimately migrating back to, and through, the surface. Yet another mechanism is prompt thermal ...
(from the article "solids, mechanics of") Temperature change can also cause strain. In an isotropic material the thermally induced extensional strains are equal in all directions, and there are no shear strains. In the simplest cases, ...
(from the article "gas") Suppose that two containers of the same gas but at different temperatures are connected by a tiny hole and that the gas is brought to a steady state. If the ...
(from the article "chromatography") Gas chromatographic detectors sense the solute vapours in the mobile phase as they emerge from the column. Thermal-conductivity detectors compare the heat-conducting ability of the exit gas stream to that ...
(from the article "gliding") The basic method of soaring, called thermaling, is to find and use rising currents of warm air, such as those above a sunlit field of ripened grain, to lift the ...
(from the article "Tammann, Gustav") ...in 1903. His research revealed that, in many cases, alloys behave as mixed crystals and that valence relationships do not hold for crystals of such metal compounds. He developed a ...
(from the article "nutrition, human") ...of new tissue in growing children and in pregnant and lactating women. Digestion and subsequent processing of food by the body also uses energy and produces heat. This phenomenon, known ...
in the French Revolution, the parliamentary revolt initiated on 9 Thermidor, year II (July 27, 1794), which resulted in the fall of Maximilien Robespierre and the collapse of revolutionary fervour ... [7 Related Articles]
discharge of electrons from heated materials, widely used as a source of electrons in conventional electron tubes (e.g., television picture tubes) in the fields of electronics and communications. The phenomenon ... [8 Related Articles]
any of a class of devices that convert heat directly into electricity using thermionic emission rather than first changing it to some other form of energy. [3 Related Articles]
(from the article "electronics") This discovery provided impetus for the development of electron tubes, including an improved X-ray tube by the American engineer William D. Coolidge and Fleming's thermionic valve (a two-electrode vacuum tube) ...
(from the article "electronic work function") ...value of the work function for a particular material varies slightly depending upon the process of emission. For example, the energy required to boil an electron out of a heated ...
electrical-resistance element made of a semiconducting material consisting of a mixture of oxides of manganese and nickel; its resistance varies with temperature. Thermistors (temperature-sensitive, or thermal, resistors) are used as ... [3 Related Articles]
powdered mixture used in incendiary bombs, in the reduction of metals from their oxides, and as a source of heat in welding iron and steel and in foundry work. [2 Related Articles]
(from the article "nitride") ...or C6H6.6S2Cl2 + 16NH3 → S4N4 + S8 + 12NH4Cl Tetrasulfur tetranitride forms thermochromic crystals, which are crystals that change colour with temperature. They are red at temperatures above 100 ...
oceanic water layer in which water temperature decreases rapidly with increasing depth. A widespread permanent thermocline exists beneath the relatively warm, well-mixed surface layer, from depths of about 200 m ... [4 Related Articles]
a temperature-measuring device consisting of two wires of different metals joined at each end. One junction is placed where the temperature is to be measured, and the other is kept ... [6 Related Articles]
(from the article "vacuum technology") Two types of thermal conductivity gauges, the Pirani and the thermocouple, determine pressure by the rate at which heat is dissipated from a hot filament. The Pirani gauge basically is ...
(from the article "pyrometer") In resistance pyrometers a fine wire is put in contact with the object. The instrument converts the change in electrical resistance caused by heat to a reading of the temperature ...
condition or state of a thermodynamic system, the properties of which do not change with time and that can be changed to another condition only at the expense of effects ... [2 Related Articles]
science of the relationship between heat, work, temperature, and energy. In broad terms, thermodynamics deals with the transfer of energy from one place to another and from one form to ... [21 Related Articles]
(from the article "materials science") In order to extract useful work from a fuel, it must first be burned so as to bring some fluid (usually steam) to high temperatures. Thermodynamics indicates that the higher ...
(from the article "thermoelectric power generator") This reversibility distinguishes thermoelectric energy converters from many other conversion systems, such as thermionic power converters. Electrical input power can be directly converted to pumped thermal power for heating or ...
any of a class of solid-state devices that either convert heat directly into electricity or transform electrical energy into thermal power for heating or cooling. Such devices are based on ... [2 Related Articles]
(from the article "electricity") ...depends on the current, develops between the two junctions. If the temperature of the hotter junction is kept low by removing heat, the second junction can be tens of degrees ...
(from the article "electricity") When two metals are placed in electric contact, electrons flow out of the one in which the electrons are less bound and into the other. The binding is measured by ...
(from the article "plastic") When a sheet of thermoplastic is heated above its Tg or Tm, it may be capable of forming a free, flexible membrane as long as the molecular weight is high ...
(from the article "thermometer") ...increase in efficiency as temperature decreases, which makes them extremely useful in measuring very low temperatures with precision. Temperatures can also be mapped, using a technique called thermography that provides ...
(from the article "ocean") Surface processes that alter the temperature and salinity of seawater drive the vertical circulation of the oceans. Known as thermohaline circulation, it continually replaces seawater at depth with water from ...
land-surface configuration that results from the melting of ground ice in a region underlain by permafrost. In areas that have appreciable amounts of ice, small pits, valleys, and hummocks are ... [1 Related Articles]
(from the article "lamp") ...in British usage) grew popular. In the meantime, however, coal gas and then natural gas for illumination were coming into wide use. Coal gas had been used as a lamp ...
emission of light from some minerals and certain other crystalline materials. The light energy released is derived from electron displacements within the crystal lattice of such a substance caused by ... [5 Related Articles]
(from the article "Table 5: Applications of Radiation Interactions in Detectors") ...light-tight paper, is mounted in plastic. Badges are checked periodically, and the degree of exposure of the film indicates the cumulative amount of radiation to which the wearer has been ...
instrument for measuring the temperature of a system. Temperature measurement is important to a wide range of activities, including manufacturing, scientific research, and medical practice. [5 Related Articles]
(from the article "undersea exploration") ...It is a metal sampler equipped with special closing valves that are actuated when the bottle, attached by one end to a wire that carries it to the desired depth, ...
(from the article "gas") ...low-temperature side to the high-temperature side to cause the high-temperature pressure to increase. The latter situation is called thermal transpiration, and the steady-state result is called the thermomolecular pressure difference. ...
a carbonate mineral, hydrated sodium carbonate (Na2CO3·H2O), found near saline lakes as an evaporation product or on arid soil as an efflorescence. It is usually associated with natron (Na2CO3·10H2O) and ...
weapon whose enormous explosive power results from an uncontrolled, self-sustaining chain reaction in which isotopes of hydrogen combine under extremely high temperatures to form helium in a process known as ... [14 Related Articles]
(from the article "fusion reactor") ...The compression is accomplished by focusing an intense laser beam or a charged particle beam, referred to as the driver, upon the small pellet (typically 1 to 10 mm in ...
fusion of two light atomic nuclei into a single heavier nucleus by a collision of the two interacting particles at extremely high temperatures, with the consequent release of a relatively ... [1 Related Articles]
the growth or flowering responses of plants to alternation of warm and cool periods. Daily temperature fluctuations produce dramatic effects on the growth or flowering of most plants. The lack ...
(from the article "bacteria") ...archaeal tree consists only of thermophilic species, and many of the methanogens in another major branch can grow at high temperatures. In contrast, no major eubacterial branch consists solely of ...
(from the article "thermocouple") A thermopile is a number of thermocouples connected in series; its results are comparable to the average of several temperature readings. A series circuit also gives greater sensitivity.
(from the article "adhesive") ...takes place simultaneously with adhesive-bond formation (as is the case with epoxy resins and cyanoacrylates), or the polymer may be formed before the material is applied as an adhesive, as ...
resort town, seat (1913) of Hot Springs county, north-central Wyoming, U.S., on the Bighorn River, opposite East Thermopolis. The site was originally within the Wind River Indian Reservation (Shoshone and ...
narrow pass on the east coast of central Greece between the Kallidhromon massif and the Maliakos Gulf, about 85 miles (136 km) northwest of Athens. In antiquity its cliffs were ... [2 Related Articles]
(from the article "Thermopylae") The pass, some 4 miles (6 km) in length, has figured in numerous invasions. There, in August 480 BC, during the second Persian invasion of Greece, a small Greek force ...
(from the article "Anatolia") ...Pergamum in the interior. In 196 he crossed the Dardanelles and brought the conflict to Europe. After some hesitation the Romans intervened against him (192-189). After two defeats, first at ...
(from the article "thermoreception") ...for example, can function both in a zoo during summer heat and on an ice floe in frigid Arctic waters. This kind of flexibility is supported by the function of ...
the maintenance of an optimum temperature range by an organism. Cold-blooded animals (poikilotherms) pick up or lose heat by way of the environment, moving from one place to another as ... [12 Related Articles]
(from the article "ocean") ...in the upper layer of gabbros. The dike layer is essentially demagnetized by the action of hydrothermal waters at the spreading centres. The dominant mechanism of permanent magnetization is the ...
(from the article "crustacean") ...marine but also freshwater and a few terrestrial; about 10,000 species.Holocene; eyes reduced or absent; brood pouch formed from dorsal extension of carapace; length about 4 mm; fresh ...
(from the article "adhesive") The polymers used in synthetic adhesives fall into two general categories-thermoplastics and thermosets. Thermoplastics provide strong, durable adhesion at normal temperatures, and they can be softened for application by heating ...
(from the article "dye") ...and, on cooling, revert to the original tightly packed structure. Dyeing at higher temperatures (120-130 °C [248-266 °F]) under pressure avoids the need for carriers. With the Thermosol process, a ...
region of increasing temperature in Earth's atmosphere that is located above the mesosphere. The base of the thermosphere (the mesopause) is at an altitude of about 80 km (50 miles), ... [3 Related Articles]
device to detect temperature changes for the purpose of maintaining the temperature of an enclosed area essentially constant. In a system including relays, valves, switches, etc., the thermostat generates signals, ... [6 Related Articles]
(from the article "Some compounds produced by bacteria on an industrial scale") ...deep-sea vents). The numbers of species found in these places may be smaller than almost anywhere else, yet the species are quite distinctive. One such species is the bacterium
tyrant of Acragas (modern Agrigento in southwestern Sicily) from 488 to 472, allied with Gelon, the powerful despot of Syracuse. Together they defeated an invading Carthaginian army at Himera in ... [3 Related Articles]
South African-born actress, who was noted for her versatility and earned an Academy Award for best actress for her performance as a real-life serial killer in Monster ... [3 Related Articles]
French photojournalist and editor (b. Oct. 24, 1924, Sete, France-d. June 23, 2001, Paris, France), transformed Paris-Match from a conventional news weekly into one of Europe's most controversial and popular ...
any member of the dinosaur subgroup, Theropoda, that includes all the flesh-eating dinosaurs. Theropods were the most diverse group of saurischian ("lizard-hipped") dinosaurs, ranging from the crow-sized [4 Related Articles]
(from the article "Low Countries, history of") ...and Cugerni. Because of the later adoption by the church of the division into civitates, a number of centres of the civitates have become the seats of bishoprics; among these ...
(from the article "library") A new use of the term thesaurus, now widespread, dates from the early 1950s in the work of H.P. Luhn, at International Business Machines Corporation (IBM), who was searching for ...
(from the article "Roget, Peter Mark") English physician and philologist remembered for his Thesaurus of English Words and Phrases (1852), a comprehensive classification of synonyms or verbal equivalents that is still popular in modern editions.reference works
(from the article "Roman law") According to thesauri inventio, or treasure trove, the final rule was that if something was found by a man on his own land, it went to him; if it was ...
dictionary of the Latin language, published at Leipzig, Ger., the most important and definitive such undertaking of modern times. It is being prepared by the Universities of Berlin, Gottingen, Leipzig, ... [1 Related Articles]
traditional law of the Tamil country of northern Sri Lanka, codified under Dutch colonial rule in 1707. The Dutch, to facilitate the administration of their colonial territories in Ceylon, established ... [1 Related Articles]
(from the article "Canadian literature") ...Coles (Forests of the Medieval World, 1993; Kurgan, 2000) grapple with metaphysical and mystical concerns through images drawn from places, travel, mythology, and nature. Sharon Thesen (The Beginning of the ...
temple in Athens dedicated to Hephaestus and Athena as patrons of the arts and crafts. Its style indicates that this, the best-preserved ancient Greek temple in the world, is slightly ... [3 Related Articles]
great hero of Attic legend, son of Aegeus, king of Athens, and Aethra, daughter of Pittheus, king of Troezen (in Argolis), or of the sea god, Poseidon, and Aethra. Legend ... [9 Related Articles]
(from the article "Two Noble Kinsmen, The") Theseus, duke of Athens, is preparing to marry Hippolyta, queen of the Amazons, accompanied by her sister, Emilia, and his friend, Pirithous, when he is called upon to wage war ...
(from the article "Midsummer Night's Dream, A") Theseus, duke of Athens, has conquered Hippolyta, the Amazon queen, and is about to wed her. Meanwhile, two lovers, Hermia and Lysander, seek refuge in the forest near Athens when ...
(from the article "Arabian Desert") ...World War I revolt, gained fame for his romantic writings about his exploits in the region. Many individuals traveled in limited parts of the desert; the most notable among them ...
(from the article "arsis and thesis") in prosody, respectively, the accented and unaccented parts of a poetic foot. Arsis, a term of Greek origin meaning "the act of raising or lifting" or "raising the foot in ...
(from the article "bastard toadflax") In Europe the name bastard toadflax is used for plants of the genus Thesium, which also has species distributed throughout Africa, Asia, and South America. The bisexual yellow or yellowish ...
in Greek religion, ancient festival held in honour of Demeter Thesmophoros and celebrated by women in many parts of the Greek world. The meaning of the name Demeter Thesmophoros still ... [2 Related Articles]
(from the article "archon") ...Third, the kingship survived in the basileus, who, as chief religious officer, presided over the Areopagus (aristocratic council) when it sat as a homicide court. Lastly there were six thesmotetai ...
ancient Greek city of Boeotia by the Thespius (modern Kanavari) River and at the eastern foot of Mt. Helicon; site of the "Eros" of Praxiteles, one of the most famous ...
Greek poet, said to have been born in the deme (district) of Icaria. According to ancient tradition, Thespis was the first actor in Greek drama. He was often called the ... [6 Related Articles]
(from the article "Antigonus II Gonatas") ...followed Pyrrhus of Epirus when the latter marched into the Peloponnese; and when Pyrrhus died in Argos in 272, Antigonus' control over Macedonia was assured. He was now also the ...
two New Testament letters written by Paul from Corinth, Greece, about AD 50 and addressed to the Christian community he had founded in Macedonia. [6 Related Articles]
city, capital and residence of the minister for northern Greece and administrative centre of the nomos (department) of Thessaloniki, on the west side of the Chalcidice (Khalkidhiki) peninsula at the ... [11 Related Articles]
region of northern Greece south of Macedonia, lying between upland Epirus and the Aegean Sea and comprising chiefly the fertile Trikala and Larissa lowlands. It is well delineated by topographical ... [12 Related Articles]
(from the article "biofeedback") Biofeedback training with brain waves has also been useful in enhancing mental functioning. "Alpha (wave) training" elicits the calming and integrative effects of meditation. Theta wave training has led to ...
(from the article "Scientology") ...among other things, of the experience of "exteriorization," the separation of individual consciousness from the body. This experience allowed him to see the spiritual self, the thetan, as the true ...
(from the article "ancient Greek civilization") Most important of all, there is the general point that the interests of hoplites and thetes, now as at other normal times, coincided; both were denied the chance of standing ...
