material quantity per unit
121Rocket engine — RS 68 being tested at NASA s Stennis Space Center. The nearly transparent exhaust is due to this engine s exhaust being mostly superheated steam (water vapor from its propellants, hydrogen and oxygen) …
122Electron mobility — This article is about the mobility for electrons and holes in metals and semiconductors. For the general concept, see Electrical mobility. In solid state physics, the electron mobility characterizes how quickly an electron can move through a… …
123Fracture mechanics — Continuum mechanics …
124Specific storage — (Ss), storativity (S), specific yield (Sy) and specific capacity are material physical properties that characterize the capacity of an aquifer to release groundwater from storage in response to a decline in hydraulic head. For that reason they… …
125Glossary of chemistry terms — This page is a glossary of chemistry terms. Chemistry has an extensive vocabulary and a significant amount of jargon. This is a list of chemical terms, including laboratory tools, glassware, and equipment. Chemistry itself is a physical science… …
126Ohm's law — This article is about the law related to electricity. For other uses, see Ohm s acoustic law. V, I, and R, the parameters of Ohm s law. Ohm s law states that the current through a conductor between two points is directly proportional to the… …
127Current density — This page is about the electric current density in electromagnetism. For the probability current density in quantum mechanics, see Probability current. Current density is a measure of the density of flow of a conserved charge. Usually the charge… …
128Battery — /bat euh ree/, n. The, a park at the S end of Manhattan, in New York City. Also called Battery Park. * * * Any of a class of devices, consisting of a group of electrochemical cells (see electrochemistry), that convert chemical energy into… …
