hardening rate
51Cryogenic treatment — A cryogenic treatment is the process of treating workpieces to cryogenic temperatures (i.e. below −190 °C (−310 °F)) to remove residual stresses and improve wear resistance on steels. The process has a wide range of applications from… …
52Spring (device) — Helical or coil springs designed for tension Compression sp …
53Literacy in India — is an indispensable means for effective social and economic participation, contributing to human development and poverty reduction, says UNESCO. [http://portal.unesco.org/education/en/ev.php URL ID=40338 URL DO=DO TOPIC URL SECTION=201.html] The… …
54Korea, North — Introduction Korea, North Background: Following World War II, Korea was split with the northern half coming under Communist domination and the southern portion becoming Western oriented. KIM Chong il has ruled North Korea since his father and the …
55Down syndrome — Classification and external resources Boy with Down syndrome assembling a …
56Nuclear fusion — Nuclear physics Radioactive decay Nuclear fission Nuclear fusion Classical dec …
57international relations — a branch of political science dealing with the relations between nations. [1970 75] * * * Study of the relations of states with each other and with international organizations and certain subnational entities (e.g., bureaucracies and political… …
58tunnels 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 …
59poison — poisoner, n. poisonless, adj. poisonlessness, n. /poy zeuhn/, n. 1. a substance with an inherent property that tends to destroy life or impair health. 2. something harmful or pernicious, as to happiness or well being: the poison of slander. 3.… …
60building construction — Techniques and industry involved in the assembly and erection of structures. Early humans built primarily for shelter, using simple methods. Building materials came from the land, and fabrication was dictated by the limits of the materials and… …
