Science / Geology / Permeability: A measure of how well a material can transmit water. Materials such as gravel, that transmit water quickly, have high values of permeability. Materials such as shale, that transmit water poorly, have low values. Permeability is primarily determined by the size of the pore spaces and their degree of interconnection. Permeability measures are expressed in units of velocity, such as centimeters per second, and assume a gradient of one vertical foot of drop per linear foot.
Technology / Home Audio / Permalloy Tape Head: A cassette tape head constructed of permalloy, an alloy made primarily of nickel and iron, used for its superior high wear resistance and permeability, offering superior frequency response at a low co MORE
Business / Agriculture / Groundwater: The water from wells and underground aquifers. An estimated 95% of the drinking water used in rural areas is from groundwater. Because of its use as drinking water, there is concern over contamination MORE