low-temperature properties
111feldspar — /feld spahr , fel /, n. any of a group of minerals, principally aluminosilicates of potassium, sodium, and calcium, characterized by two cleavages at nearly right angles: one of the most important constituents of igneous rocks. Also, felspar.… …
112nitrogen group element — ▪ chemical elements Introduction any of the chemical elements that constitute Group Va of the periodic table (see Figure >). The group consists of nitrogen (N), phosphorus (P), arsenic (As), antimony (Sb), and bismuth (Bi). The elements share… …
113Absolute zero — For other uses, see Absolute Zero (disambiguation). Absolute zero is the theoretical temperature at which entropy reaches its minimum value. The laws of thermodynamics state that absolute zero cannot be reached using only thermodynamic means. A… …
114Lubricant — A lubricant is a substance introduced to reduce friction between moving surfaces. It may also have the function of transporting foreign particles and of distributing heat. The property of reducing friction is known as lubricity. A good lubricant… …
115Light-emitting diode — LED redirects here. For other uses, see LED (disambiguation). Light emitting diode Red, pure green and blue LEDs of the 5mm diffused type Type Passive, optoelectronic Working principle Electr …
116Specific heat capacity — Specific heat capacity, also known simply as specific heat, is the measure of the heat energy required to increase the temperature of a unit quantity of a substance by a certain temperature interval. The term originated primarily through the work …
117Countercurrent exchange — Counter heat current exchange: Note the gradually declining differential and that the once hot and cold streams exit at the reversed temperature difference; the hotter entering stream becomes the exiting cooler stream and vice versa.… …
118Combined cycle — Thermodynamics …
119igneous rock — Any of various crystalline or glassy, noncrystalline rocks formed by the cooling and solidification of molten earth material (magma). Igneous rocks comprise one of the three principal classes of rocks, the others being metamorphic and sedimentary …
120Silicone — Not to be confused with the metalloid chemical element Silicon. Silicone caulk can be used as a basic sealant against water and air penetration. Silicones are inert, synthetic compounds with a variety of forms and uses. Typically heat resistant… …
