overall heat-transfer resistance
51Hydraulic analogy — The electronic–hydraulic analogy (derisively referred to as the drain pipe theory by Oliver Heaviside) is the most widely used analogy for electron fluid in a metal conductor. Since electric current is invisible and the processes at play in… …
52food preservation — Any method by which food is protected against spoilage by oxidation, bacteria, molds, and microorganisms. Traditional methods include dehydration, smoking, salting, controlled fermentation (including pickling), and candying; certain spices have… …
53Curtain wall — For defensive curtain walls in medieval buildings, see Curtain wall (fortification). Glass curtain wall of the Bauhaus Dessau A curtain wall is an outer covering of a building in which the outer walls are non structural, but merely keep out the… …
54Passive house — The term passive house ( Passivhaus in German) refers to the rigorous, voluntary, Passivhaus standard for energy use in buildings. It results in ultra low energy buildings that require little energy for space heating or cooling. [… …
55Fire door — A fire door is a type of door, or barrier used as a passive fire protection item within buildings to prevent the spread of fire or smoke which may consist of dangerous chemicals. It is usually the only means of allowing people to pass through a… …
56Reynolds number — In fluid mechanics and heat transfer, the Reynolds number mathrm{Re} is a dimensionless number that gives a measure of the ratio of inertial forces ({old mathrm V} ho) to viscous forces (mu / L) and, consequently, it quantifies the relative… …
57Atmospheric reentry — refers to the movement of human made or natural objects as they enter the atmosphere of a planet from outer space, in the case of Earth from an altitude above the edge of space. This article primarily addresses the process of controlled reentry… …
58Centrifugal compressor — Centrifugal compressors, sometimes termed radial compressors, are a sub class of dynamic axisymmetric work absorbing turbomachinery.[1] Centrifugal impeller with a highly polished surface likely to improve performance …
59Water pollution — Raw sewage and industrial waste flows across international borders New River passes from Mexicali to Calexico, California. Water pollution is the contamination of water bodies (e.g. lakes, rivers, oceans and groundwater). Water p …
60Thermographic camera — A thermographic camera, sometimes called a FLIR (Forward Looking InfraRed), or an infrared camera less specifically, is a device that forms an image using infrared radiation, similar to a common camera that forms an image using visible light.… …
