upper explosive limit concentration
41chemical element — Introduction also called element, any substance that cannot be decomposed into simpler substances by ordinary chemical processes. Elements are the fundamental materials of which all matter is composed. This article considers the… …
42drug — drug1 /drug/, n., v., drugged, drugging. n. 1. Pharm. a chemical substance used in the treatment, cure, prevention, or diagnosis of disease or used to otherwise enhance physical or mental well being. 2. (in federal law) a. any substance… …
43Drug — /droog/, n. Zoroastrianism. the cosmic principle of disorder and falsehood. Cf. Asha. [ < Avestan drauga] * * * I Any chemical agent that affects the function of living things. Some, including antibiotics, stimulants, tranquilizers,… …
44environmental works — ▪ civil engineering Introduction infrastructure that provides cities and towns with water supply, waste disposal, and pollution control services. They include extensive networks of reservoirs, pipelines, treatment systems, pumping stations …
45Formaldehyde — For other uses, see Formaldehyde (disambiguation). Formaldehyde …
46lake — lake1 /layk/, n. 1. a body of fresh or salt water of considerable size, surrounded by land. 2. any similar body or pool of other liquid, as oil. 3. (go) jump in the lake, (used as an exclamation of dismissal or impatience.) [bef. 1000; ME lak(e) …
47Lake — /layk/, n. Simon, 1866 1945, U.S. engineer and naval architect. * * * I Relatively large body of slow moving or standing water that occupies an inland basin. Lakes are most abundant in high northern latitudes and in mountain regions, particularly …
48Russia — /rush euh/, n. 1. Also called Russian Empire. Russian, Rossiya. a former empire in E Europe and N and W Asia: overthrown by the Russian Revolution 1917. Cap.: St. Petersburg (1703 1917). 2. See Union of Soviet Socialist Republics. 3. See Russian… …
49tunnels and underground excavations — ▪ engineering Introduction Great tunnels of the world Great tunnels of the worldhorizontal underground passageway produced by excavation or occasionally by nature s action in dissolving a soluble rock, such as limestone. A vertical opening …
50Switzerland — /swit seuhr leuhnd/, n. a republic in central Europe. 7,248,984; 15,944 sq. mi. (41,294 sq. km). Cap.: Bern. French, Suisse. German, Schweiz. Italian, Svizzera. Latin, Helvetia. * * * Switzerland Introduction Switzerland Background: Switzerland s …
