TERMIUM Plus^®

Record 3,  Textual support,  English

Record number: 3, Textual support number: 1 DEF

An inert light gas, He, which is odorless, colorless, and not flammable.  2, record 3, English, - helium

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Helium is extracted from natural gas sources in the Texas and Oklahoma ... and Southwest Kansas ... The element is believed to be trapped in the natural gas pockets after disintegration from uranium and thorium.  3, record 3, English, - helium

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... uses for helium[:] filling party balloons as it is a much safer gas (non-flammable); widely used as an inert gas shield for arc welding; high speed push gas inside air to air missiles for guidance corrections; protective gas in growing silicon and germanium crystals, and in titanium and zirconium production; cooling medium for nuclear reactors, helium won’t become radioactive; a mixture of 80% helium and 20% oxygen is used as an artificial atmosphere for divers and others working under pressure; cryogenics and superconductivity; rare document preservation ... Independence); as a gas for supersonic wind tunnels; pressurizing agent for liquid fuel rockets (inert so won’t react); leak detection agent for extremely small leaks; nuclear detonation simulations (using conventional explosives); isotopic dating by helium ratios (seawater, ocean beds,etc); helium/neon lasers; helium cardio-pulmonary resuscitation pump (heart surgery); helium filled border patrol "AEROSTAT" monitoring blimps.  4, record 3, English, - helium

Record number: 3, Textual support number: 1 OBS

Helium has an atomic number of 2, an atomic weight of 4, density of 0. 1785 kg/m³ at STP. Helium can be liquefied at 4. 2 K(-269°C).  2, record 3, English, - helium

Record 3,  Textual support,  French

Record number: 3, Textual support number: 1 DEF

Gaz rare le plus léger.  2, record 3, French, - h%C3%A9lium

Record number: 3, Textual support number: 1 OBS

(Élément de symbole He). Numéro atomique : 2. Masse atomique : 4,0026. Température de fusion : -269,7 °C. Température d'ébullition : -268,934 °C. Masse volumique : 0,126 g/cm³. État d'oxydation : 0.  2, record 3, French, - h%C3%A9lium

Record number: 3, Textual support number: 2 OBS

Gaz rare utilisé en mélange pour la plongée profonde.  3, record 3, French, - h%C3%A9lium

Record 3,  Textual support,  Spanish

Record 4,  Textual support,  English

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The composition of the atmosphere -its gases and particles- plays a critical role in connecting human welfare with global and regional changes because the atmosphere links all of the principal components of the Earth system.  4, record 4, English, - composition%20of%20the%20atmosphere

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Present Composition of the Atmosphere. The atmosphere is comprised of gases which are considered to be permanent(gases which remain essentially constant by percent) and gases considered to be variable(gases which have changing concentrations over a finite period of time). PERMANENT gases in the atmosphere by percent are : Nitrogen=78. 1%; Oxygen=20. 9%. Note that these two permanent gases together comprise 99% of the atmosphere. Other permanent gases : Argon=0. 9%; Neon=0. 002%; Helium=0. 0005%; Krypton=0. 0001%; Hydrogen=0. 00005%. VARIABLE gases in the atmosphere and typical percentage values are : Water vapor=0 to 4%; Carbon Dioxide=0. 035%; Methane=0. 0002%; Ozone=0. 000004%.  5, record 4, English, - composition%20of%20the%20atmosphere

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composition of the atmosphere: term standardized by ISO.  6, record 4, English, - composition%20of%20the%20atmosphere

Record 4,  Textual support,  French

Record number: 4, Textual support number: 1 DEF

Proportion relative de chacune des substances qui forment l'atmosphère terrestre.  2, record 4, French, - composition%20de%20l%27atmosph%C3%A8re

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La composition de l'atmosphère est assez hétérogène. La masse principale est constituée par un mélange gazeux, l'air sec, auquel s'ajoutent une très faible proportion d'aérosols ainsi que de l'eau soit sous forme condensée (liquide ou solide) soit à l'état de vapeur. Ainsi sur les dix tonnes qui représentent à peu près la masse de l'atmosphère au-dessus d'un même carré de sol, au niveau moyen de la mer, il y a 9,98 tonnes d'air, un peu moins de 20 kilogrammes d'eau (soit l'équivalent de 20 mm d'eau pluviale) et environ un kilogramme de matériaux solides divers très finement divisés dont une très faible partie de micro-organismes.  4, record 4, French, - composition%20de%20l%27atmosph%C3%A8re

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Dans l'homosphère, jusqu'à cent kilomètres d'altitude, la composition chimique de l'atmosphère est homogène, c'est-à-dire relativement stable. Plus haut, dans l'hétérosphère, la composition de l'atmosphère est qualifiée de stratifiée.  2, record 4, French, - composition%20de%20l%27atmosph%C3%A8re

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composition de l'atmosphère : terme normalisé par l'ISO.  5, record 4, French, - composition%20de%20l%27atmosph%C3%A8re

Record 4,  Textual support,  Spanish

Record number: 4, Textual support number: 1 DEF

Características físico-químicas de la atmósfera.  1, record 4, Spanish, - composici%C3%B3n%20de%20la%20atm%C3%B3sfera

Record 5,  Textual support,  English

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... liquid helium [is a] gas extracted from selected natural gas wells. ... [It is] used for: Studies of low temperature material properties. -Superconducting magnets. -Superconducting sensors (i.e. SQUIDS).  3, record 5, English, - liquid%20helium

Record number: 5, Textual support number: 2 CONT

The temperature of liquid helium is normally 4 K, that is, four degrees above absolute zero.  2, record 5, English, - liquid%20helium

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Liquid helium exists below 4. 2K and is used to cool superconductors below their transition temperatures.  4, record 5, English, - liquid%20helium

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A remarkable transition occurs in the properties of liquid helium at the temperature 2.17 K, called the "lambda point" for helium. Part of the liquid becomes a "superfluid", a zero viscosity fluid which will move rapidly through any pore in the apparatus.  5, record 5, English, - liquid%20helium

Record number: 5, Textual support number: 1 OBS

LHe: The symbol for liquid helium.  2, record 5, English, - liquid%20helium

Record 5,  Textual support,  French

Record number: 5, Textual support number: 1 CONT

L'hélium liquide (-270 °C) est reçu directement liquéfié. Ce gaz a la température d'ébullition la plus basse. Son absence de viscosité à très basse température est remarquable. Il est très peu réactif : il est utilisé pour pressuriser les ergols liquides en haut des réservoirs et pour commander certaines vannes.  2, record 5, French, - h%C3%A9lium%20liquide

Record 5,  Textual support,  Spanish

Record 6,  Textual support,  English

Record number: 6, Textual support number: 1 CONT

The thought experiments are concerned with the behavior of two types of helium atoms, denoted³He and^4</sup>He. These two types differ only in the nature of their nuclei. The³He nucleus contains two protons and one neutron, whereas the^4</sup>He nucleus contains two protons and two neutrons.  4, record 6, English, - helium%2D4

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The goal of the project at the VU is to reach BEC with helium-4 atoms in the metastable 2 [superscript 3S state(He).  5, record 6, English, - helium%2D4

Record 6,  Textual support,  French

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L'hélium existe en deux isotopes : l'hélium-4 (⁴He) est l'isotope courant, représentant pratiquement 100% de l'hélium naturel. Son noyau comporte deux protons et deux neutrons (un nombre pair de nucléons) de sorte que l'atome est un boson.  1, record 6, French, - h%C3%A9lium%2D4

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Propriétés de l'He⁴.  4, record 6, French, - h%C3%A9lium%2D4

Record 6,  Textual support,  Spanish

Record number: 6, Textual support number: 1 CONT

[...] dos clases de átomos de helio:³He y⁴He, que se distinguen por la naturaleza de sus núcleos. El núcleo de³He contiene dos protones y un neutrón; el de⁴He, dos protones y dos neutrones. Ambos núcleos poseen, pues, el mismo número de protones, lo que indica que presentarán la misma carga eléctrica.  1, record 6, Spanish, - 4He

Record 7,  Textual support,  English

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The thought experiments are concerned with the behavior of two types of helium atoms, denoted^3sup>He4He. These two types differ only in the nature of their nuclei. The3He nucleus contains two protons and one neutron, whereas the4</sup>He nucleus contains two protons and two neutrons.  4, record 7, English, - helium%2D3</sup>

Record 7,  Textual support,  French

Record number: 7, Textual support number: 1 CONT

L'autre isotope est l'hélium-3 (³He) qui ne comprend qu'un seul neutron et deux protons, de sorte que l'atome d'hélium-3 (³)He est un fermion. L'hélium-3 est très rare (un atome sur un million) et s'obtient en pratique de la désintégration du tritium, isotope instable de l'hydrogène utilisé principalement dans les [...] armes nucléaires.  4, record 7, French, - h%C3%A9lium%203

Record 7,  Textual support,  Spanish

Record number: 7, Textual support number: 1 CONT

[...] dos clases de átomos de helio:³He y⁴He, que se distinguen por la naturaleza de sus núcleos. El núcleo de³He contiene dos protones y un neutrón; el de⁴He, dos protones y dos neutrones. Ambos núcleos poseen, pues, el mismo número de protones, lo que indica que presentarán la misma carga eléctrica.  1, record 7, Spanish, - 3He

Record 8,  Textual support,  English

Record number: 8, Textual support number: 1 DEF

The nuclear process that powers the sun. It involves the fusion of nuclei in 3 kinds of collisions. The cycle starts for any one proton when it collides with another. This collision produces a deuterium nucleus, a neutrino that shoots off into space and a position that eventually annihilates a stray electron. Next, the deuterium nucleus is hit by another proton, producing a nucleus of helium -3 and a burst of gamma rays. The helium -3 hits another helium -3, producing a nucleus of inert helium and two protons. These 2 protons now start the proton-proton cycle over again.  4, record 8, English, - proton%2Dproton%20chain

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Deep within the sun a series of nuclear reactions called the proton-proton chain converts hydrogen(protons) into helium by merging sets of 4 hydrogen nuclei into one helium nucleus(alpha particle).  4, record 8, English, - proton%2Dproton%20chain

Record 8,  Textual support,  French

Record number: 8, Textual support number: 1 CONT

La chaîne proton-proton ne comporte que 3 étapes. Le premier mécanisme est celui des étoiles chaudes, le second celui des étoiles froides. Dans le soleil à la jonction des 2 types d'étoiles, les 2 régimes doivent fonctionner simultanément. Environ 638 millions de tonnes d'hydrogène sont transformés par seconde, dont 0.6 p. 100 est libéré sous forme d'énergie; à ce rythme, la perte de masse par seconde est de 3,83 millions de tonnes.  2, record 8, French, - cycle%20proton%2Dproton

Record number: 8, Textual support number: 2 CONT

Mais il fallut attendre 1937-1938 avant que la connaissance empirique des sections efficaces de capture ait suffisamment progressé pour permettre à Von Weizsacker et à Bethe d'isoler enfin les deux réactions responsables de la génération d'énergie dans la majorité des étoiles, la chaîne proton-proton et le cycle du carbone, toutes deux transformant quatre protons en un noyau d'hélium; mais par des processus différents.  2, record 8, French, - cycle%20proton%2Dproton

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Au centre du Soleil, à 15 millions de degrés, c'est le cycle proton-proton qui est le plus efficace et contribue à l'émission d'énergie pour environ 90 p. 100.  1, record 8, French, - cycle%20proton%2Dproton

Record 8,  Textual support,  Spanish