- 行业: Printing & publishing
- Number of terms: 178089
- Number of blossaries: 0
- Company Profile:
McGraw Hill Financial, Inc. is an American publicly traded corporation headquartered in Rockefeller Center in New York City. Its primary areas of business are financial, publishing, and business services.
A component of a steam-generating unit in which steam, after it has left the boiler drum, is heated above its saturation temperature. The amount of superheat added to the steam is influenced by the location, arrangement, and amount of superheater surface installed, as well as the rating of the boiler. The superheater may consist of one or more stages of tube banks arranged to effectively transfer heat from the products of combustion. The primary, or initial, stage of a superheater usually consists of a tube bank which is swept by gases that already have given up some of their heat to the final or outlet stage of the superheater. The transfer of heat from the gases to the steam is predominantly by convection; thus this section of the superheater usually is referred to as a convection superheater.
Industry:Science
A component of a steam-generating unit that absorbs heat from the products of combustion after they have passed through the steam-generating and superheating sections. The name, accepted through common usage, is indicative of savings in the fuel required to generate steam.
Industry:Science
A component of a steam-generating unit that absorbs heat from the products of combustion after they have passed through the steam-generating and superheating sections. Heat recovered from the gas is recycled to the furnace by the combustion air and is absorbed in the steam-generating unit, with a resultant gain in overall thermal efficiency. Use of preheated combustion air also accelerates ignition and promotes rapid burning of the fuel.
Industry:Science
A component of an aircraft that develops either shaft horsepower or thrust and incorporates design features most advantageous for aircraft propulsion. An engine developing shaft horsepower requires an additional means to convert this power to useful thrust for aircraft, such as a propeller, a fan, or a helicopter rotor. It is common practice in this case to designate the unit developing shaft horsepower as the aircraft engine, and the combination of engine and propeller, for example, as an aircraft power plant. In case thrust is developed directly as in a turbojet engine, the terms engine and power plant are used interchangeably.
Industry:Science
A component of most systems in which air is used for industrial processes, for ventilation, or for comfort air conditioning. The function of an air filter is to reduce the concentration of solid particles in the airstream to a level that can be tolerated by the process or space occupancy purpose. Degrees of cleanliness required and economics of the situation (life cycle costs) influence the selection of equipment.
Industry:Science
A composite gland in most vertebrates, containing both exocrine cells—which produce and secrete enzymes involved in digestion—and endocrine cells, arranged in separate islets which elaborate at least two distinct hormones, insulin and glucagon, both of which play a role in the regulation of metabolism, and particularly of carbohydrate metabolism. This article discusses the anatomy, histology, embryology, physiology, and biochemistry of the vertebrate pancreas.
Industry:Science
A compound containing one of the halogens (fluorine (F), chlorine (Cl), bromine (Br), iodine (I)) and another element or organic group. Halides have the general formula M<i><sub>x</sub></i>X<i><sub>y</sub></i>, where M is a metal or organic group and X is a halogen. Halides are composed of almost every element in the periodic table, and they are referred to as fluorides, chlorides, bromides, or iodides.
Industry:Science
A compound containing the —CN group, for example, potassium cyanide, KCN; calcium cyanide, Ca(CN)<sub>2</sub>; and hydrocyanic (or prussic) acid, HCN. Chemically, the simple inorganic cyanides resemble chlorides in many ways. Organic compounds containing this group are called nitriles. Acrylonitrile, CH<sub>2</sub>CHCN, is an important starting material in the manufacture of fabrics, plastics, and synthetic rubber.
Industry:Science
A compound containing the hydroxide ion (OH<sup>−</sup>) and having the general formula M(OH)<sub>n</sub>, where M represents a metal. Hydroxides are a subset of compounds containing the hydroxyl group (–OH) and range in chemical character from strongly basic, to amphoteric (having both acidic and basic characteristics), to essentially acidic. The hydroxide ion has a closed-shell electronic structure with a singlet ground state (<sup>1</sup>Σ<sup>+</sup>).
Industry:Science
A compound containing the –OCN group, typically a salt or ester of cyanic acid (HOCN). The cyanate ion is ambidentate, that is, it has two reactive sites, because it can bind through the oxygen (O) or the nitrogen (N). Cyanate is commonly N-bonded with most nonmetallic elements, presumably because of the small charge density on the oxygen. Cyanic acid has the structure H–O=C≡N, but it may exist in an isomeric form known as isocyanic acid, H–N=C=O. The cyanates are isomeric with fulminates, where the carbon and the nitrogen are transposed (–ONC).
Industry:Science
