- 行业: Printing & publishing
- Number of terms: 178089
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- 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 rare, hereditary blood disorder marked by a tendency toward excessive bleeding. It is almost entirely restricted to males, and is transmitted as a sex-linked mendelian recessive trait passing from an affected male through an unaffected or very mildly affected daughter to appear again in a grandson. Queen Victoria was a carrier, and several of her male descendants were affected.
Industry:Science
A rarefied portion of the atmosphere, lying in a spherical shell between 50 and 300 mi (80 and 500 km) above the Earth's surface, where the temperature increases dramatically with altitude. Many satellites orbit in the upper thermosphere, and the drag on these satellites exerted by the atmosphere eventually brings them down to burn up in the lower atmosphere.
Industry:Science
A rarer order of the class Anopla in the phylum Rhynchocoela, characterized by an unarmed proboscis, a thin gelatinous dermis, and either a two-layered (outer circular and inner longitudinal strata) or three-layered (outer circular, median longitudinal, and inner circular strata) body musculature. Many members (such as <i>Tubulanus = Carinella</i>) show primitive features, such as a peripherally located nervous system and the absence of ocelli, ciliated grooves, and intestinal diverticula. Cerebral organs, if present, are generally simple.
Industry:Science
A rate of cooling that is equivalent to the removal of heat at 200 Btu/min (200 kilojoules/min), 12,000 Btu/h (13 megajoules/h), or 288,000 Btu/day (300 MJ/day). This unit of measure stems from the original use of ice for refrigeration. One pound of ice, in melting at 32°F (0°C), absorbs as latent heat approximately 144 Btu/lb (335 J/kg), and 1 ton (0.9 metric ton) of ice, in melting in 24 h, absorbs 288,000 Btu/day (300 MJ/day). In Europe, where the metric system is used, the equivalent cooling unit is the frigorie, which is a kilogram calorie, or 3.96 Btu. Thus 3000 frigories/h is approximately 1 ton of refrigeration. A standard ton of refrigeration is one developed at standard rating conditions of 5°F (−15°C) evaporator and 86°F (30°C) condenser temperatures, with 9°F (−13°C) liquid subcooling and 9°F (−13°C) suction superheat.
Industry:Science
A rather dense, banded limestone (see <b>illus.</b>), sometimes moderately porous, that is formed by evaporation about springs, as is tufa, or in caves as stalactites, stalagmites, or dripstone. Where travertine or tufa (calcareous sinter) is deposited by hot springs, it may be the result of the loss of carbon dioxide from the waters as pressure is released upon emerging at the surface; the release of carbon dioxide lowers the solubility of calcium carbonate, which precipitates. High rates of evaporation in hot-spring pools also lead to supersaturation. Travertine formed in caves is simply the result of complete evaporation of waters containing mainly calcium carbonate.
Industry:Science
A ratio comparison of two quantities expressed by using 100 equal parts, or hundredths; symbolized %. There are three major uses of percent: part of a whole, rate, and comparison of any two quantities.
Industry:Science
A reaction in which hydrogen is detached from a molecule. The reaction is strongly endothermic; therefore, heat must be supplied to maintain the reaction temperature. Since carbon-carbon bonds are easier to break than carbon-hydrogen bonds, highly selective reaction conditions are required to cause the molecule to dehydrogenate rather than break apart into small molecules (for example, methane) and carbon (coke). Superheated steam (725°C or 1337°F) is often mixed with the dehydrogenation reactor feed to provide the needed heat of reaction, lower the partial pressure and enhance the equilibrium conversion, and decoke the catalyst to extend the reactor onstream time. In addition, excess hydrogen is sometimes added to the feed to depress coke formation and diminish the breakup of large molecules (for example, styrene) into smaller molecules of much less economic value.
Industry:Science
A reaction in which suspended particles are aggregated or clumped. It occurs upon the admixture of another type of particle, a change in the composition of the suspending fluid, or the addition of a soluble agent that acts as a bridge between two or more particles. The reaction is a secondary one in that the process resulting in agglutination occurs after the primary antigen-antibody linkage has taken place.
Industry:Science
A reaction that occurs when an antigen combines with a corresponding antibody to produce an immune complex. A substance that induces the immune system to form a corresponding antibody is called an immunogen. All immunogens are also antigens because they react with corresponding antibodies; however, an antigen may not be able to induce the formation of an antibody and therefore may not be an immunogen. For instance, lipids and all low-molecular-weight substances are not immunogenic. However, many such substances, termed haptens, can be attached to immunogens, called carriers, and the complex then acts as a new immunogen capable of eliciting antibody to the attached hapten.
Industry:Science
A receive-only radar used for search, tracking, surveillance, identification, guidance, and mapping. The techniques used are similar to those in radiometry; passive radar could be said to be a branch of radiometry. Military applications are quite different, however, from other uses of radiometry in that the source is usually not known to exist until detected by the radar, and the operator has no control over the position of the source but must determine it and sometimes track it. There are often other sources in the vicinity, so that discriminating between competing sources is important in military applications. The operation of passive radars depends upon the detection of microwave or infrared radiation from warm bodies.
Industry:Science
