Structural steelStructural steel is a category of steel used for making construction materials in a variety of shapes. Many structural steel shapes take the form of an elongated beam having a of a specific cross section. Structural steel shapes, sizes, chemical composition, mechanical properties such as strengths, storage practices, etc., are regulated by standards in most industrialized countries. Most structural steel shapes, such as -beams, have high second moments of area, which means they are very stiff in respect to their cross-sectional area and thus can support a high load without excessive sagging.
Jauge de déformationLe but des extensomètres (ou jauges extensométriques) à fils résistants ou jauges résistives de déformation (ou, abusivement, jauges de contrainte) est de traduire la déformation d'une pièce en variation de résistance électrique (plus les extensomètres s'étirent, plus leurs résistances augmentent). Elles consistent en des spires rapprochées et sont généralement fabriquées à partir d'une mince feuille métallique (quelques μm d'épaisseur) et d'un isolant électrique, que l'on traite comme un circuit imprimé (par lithographie et par attaque à l'acide).
Glass coloring and color markingGlass coloring and color marking may be obtained in several ways. by the addition of coloring ions, by precipitation of nanometer-sized colloids (so-called striking glasses such as "gold ruby" or red "selenium ruby"), by colored inclusions (as in milk glass and smoked glass) by light scattering (as in phase separated glass) by dichroic coatings (see dichroic glass), or by colored coatings Ordinary soda-lime glass appears colorless to the naked eye when it is thin, although iron oxide impurities produce a green tint which can be viewed in thick pieces or with the aid of scientific instruments.
