contact gas separation
51Caesium — xenon ← caesium → barium Rb ↑ Cs ↓ Fr …
52Binary star — For the hip hop group, see Binary Star (band). Hubble image of the …
53international 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… …
54rare-earth element — /rair errth /, Chem. any of a group of closely related metallic elements, comprising the lanthanides, scandium, and yttrium, that are chemically similar by virtue of having the same number of valence electrons. Also called rare earth metal. [1955 …
55animal development — Introduction the processes that lead eventually to the formation of a new animal starting from cells derived from one or more parent individuals. Development thus occurs following the process by which a new generation of organisms is produced by …
56physical science, principles of — Introduction the procedures and concepts employed by those who study the inorganic world. physical science, like all the natural sciences, is concerned with describing and relating to one another those experiences of the surrounding… …
57Tire — This article is about tires used on road vehicles, including pneumatic tires and solid tires. For railroad tires, see railway tires. For other uses, see tire (disambiguation) or tyre.Tires, or tyres (in American and British English, respectively) …
58Crystallization — Crystallizing and Crystallized redirect here. For the action adventure video game, see Crystalis. For the 2009 song by The xx, see Crystalised. For other uses, see Crystallization (disambiguation). Crystallization …
59Sewage treatment — The objective of sewage treatment is to produce a disposable effluent without causing harm to the surrounding environment, and also prevent pollution.[1] Sewage treatment, or domestic wastewater treatment, is the process of removing contaminants… …
60Mars Science Laboratory — Vue d artiste du rover MSL. Caractéristiques Organ …
