ค้นเจอ 49 รายการ

สมมูลเคมี

หมายถึงน. จำนวนเลขที่บ่งแสดงนํ้าหนักของสารที่ทำปฏิกิริยาโดยทางตรงหรือทางอ้อมได้พอดีกับ ๑.๐๐๘ หน่วยนํ้าหนักเดียวกันของธาตุไฮโดรเจน หรือกับ ๘ หน่วยนํ้าหนักเดียวกันของธาตุออกซิเจน. (อ. chemical equivalent).

Adsorption Water

แปลว่า(Concrete Engineering) Water held on surfaces in a material by either physical and/or chemical forces.

Isomers

แปลว่า(Environmental Engineering) Two or more different compounds with the same chemical formula but different structure and characteristics.

สมการเคมี

หมายถึง(เคมี) น. สมการที่เขียนขึ้นโดยอาศัยสัญลักษณ์ของธาตุ เพื่อแสดงปฏิกิริยาเคมีและปริมาณของธาตุต่าง ๆ ที่เกี่ยวข้องในปฏิกิริยาเคมีนั้น ๆ. (อ. chemical equation).

Oxidative phosphorylation

แปลว่า(Environmental Engineering) The synthesis of the energy storage compound adenosine triphosphate (ATP) from adenosine diphosphate (ADP) using a chemical substrate and molecular oxygen.

Sulfate Attack

แปลว่า(Concrete Engineering) Deleterious chemical and/or physical re-action between sulfates in ground water or soil and certain constituents in cement, which result in expansion and disruption of the concrete.

Blow Down

แปลว่า(english) Process that rids boiler feed water of solids and maintains the proper chemical balance of the feed water. Blow down can also be used to rid drum(s) of excess water.

Bright Dipping

แปลว่า(english) Chemical polishing of aluminum, often by treatment with a mixture of nitric acid and phosphoric acid, yielding a mirror-shiny (specular) highly reflective surface. It is almost always followed by anodizing to protect the surface and provide some choice of color.

Bismuth

แปลว่า(english) Chemical symbol Bi. A soft, course cystalline heavy metal with a silvery white color and pinkish tinge; usually produced as a by-product of copper,leaad and other metals. Has a thermal conductivity lower than all other metals except mercury. Used as alloying agent but leading use is in pharmaceuticals.

Zinc

แปลว่า(english) Chemical Symbol Zn. Element No. 30 of the periodic system; atomic weight 65.38. Blue-white metal; when pure, malleable and ductile even at ordinary temperatures; melting point 787 (degrees) F.; boiling point 1665 (degrees) F., specific gravity 7.14. Can be electrodeposited; it is extensively used as a coating for steel and sheet zinc finds many outlets, such as dry batteries, etc. Zinc-base alloys are of great importance in die casting. Its most important alloy is brass.

Aging 2

แปลว่า(english) A change in properties that occurs at ambient or moderately elevated temperatures after hot working or a heat treating operation (quench aging in ferrous alloys), or after a cold working operation (strain aging). The change in properties is often, but not always, due to a phase change (precipitation), but does not involve a change in chemical composition. In a metal or alloy, a change in properties that generally occurs slowly at room temperature and more rapidly at higher temperatures.

Carbonation

แปลว่า(Concrete Engineering) 1) Reaction between the products of portland cement (soluble calcium hydroxides), water and carbon dioxide to produce insoluble calcium carbonate (efflorescence). 2) Soft white, chalky surface dusting of freshly placed, unhardened concrete caused by carbon dioxide from unvented heaters or gasoline powered equipment in an enclosed space. 3) Carbonated, dense, impermeable to absorption, top layer of the surface of concrete caused by surface reaction to carbon dioxide. This carbonated layer becomes denser and deeper over a period of time. 4) Reaction with carbon dioxide which produces a slight shrinkage in concrete. Improves chemical stability. Concrete masonry units during manufacturing may be deliberately exposed to carbon dioxide after reaching 80% strength to induce carbonation shrinkage to make the units more dimensionally stable. Future drying shrinkage is reduced by as much as 30%.