diffusion radiation
51Manhattan Project — This article is about the atomic bomb project. For other uses, see Manhattan Project (disambiguation). Manhattan District The Manhattan Project created the first nuclear bombs. The Trinity test …
52Thermodynamic temperature — is the absolute measure of temperature and is one of the principal parameters of thermodynamics. Thermodynamic temperature is an “absolute” scale because it is the measure of the fundamental property underlying temperature: its null or zero point …
53photography, technology of — Introduction equipment, techniques, and processes used in the production of photographs. The most widely used photographic process is the black and white negative–positive system (Figure 1 >). In the camera the lens projects an image of… …
54Enriched uranium — Proportions of uranium 238 (blue) and uranium 235 (red) found naturally versus enriched grades Enriched uranium is a kind of uranium in which the percent composition of uranium 235 has been increased through the process of isotope separation.… …
55Heat transfer — is a discipline of thermal engineering that concerns the exchange of thermal energy from one physical system to another. Heat transfer is classified into various mechanisms, such as heat conduction, convection, thermal radiation, and phase change …
56Électron — Traduction à relire Electron → …
57Photoacoustique — Par définition l effet photoacoustique désigne la génération d ondes mécaniques dans un objet illuminé par une radiation électromagnétique. Le premier à rapporter l existence d un tel phénomène est Alexander Graham Bell en 1880, qui découvrit que …
58Scattering — is a general physical process where some forms of radiation, such as light, sound, or moving particles, are forced to deviate from a straight trajectory by one or more localized non uniformities in the medium through which they pass. In… …
59cosmos — /koz meuhs, mohs/, n., pl. cosmos, cosmoses for 2, 4. 1. the world or universe regarded as an orderly, harmonious system. 2. a complete, orderly, harmonious system. 3. order; harmony. 4. any composite plant of the genus Cosmos, of tropical… …
60IONOSPHÈRE — L’atmosphère est ionisée sur toute la surface du globe à partir d’une altitude d’environ 60 km, au dessous de laquelle l’ionisation est négligeable; cette région de l’atmosphère est appelée ionosphère. Vers les altitudes supérieures, l’ionisation …
