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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 relationship existing between two fluid flows when they have identical types of forces that are parallel at all corresponding points, with magnitudes related by a constant scale factor. Dynamic similarity makes it possible to scale results from model tests to predict corresponding results for the full-scale prototype.
Industry:Science
A relatively common aggregate of mineral grains. Some rocks consist essentially of but one mineral species (monomineralic, such as quartzite, composed of quartz); others consist of two or more minerals (polymineralic, such as granite, composed of quartz, feldspar, and biotite). Rock names are not given for those rare combinations of minerals that constitute ore deposits, such as quartz, pyrite, and gold. In the popular sense rock is considered also to denote a compact substance, one with some coherence; but geologically, friable volcanic ash also is a rock. A genetic classification of rocks follows: <ul class="articlebody"><li>Igneous</li><ul class="articlebody"><li>Intrusive</li><ul class="articlebody"><li>Plutonic (deep)</li><li>Hypabyssal (shallow)</li></ul><li>Extrusive</li><ul class="articlebody"><li>Flow</li><li>Pyroclastic (explosive)</li></ul></ul><li>Sedimentary</li><ul class="articlebody"><li>Clastic (mechanical or detrital)</li><li>Chemical (crystalline or precipitated)</li><li>Organic (biogenic)</li></ul><li>Metamorphic</li><ul class="articlebody"><li>Cataclastic</li><li>Contact metamorphic and pyrometasomatic</li><li>Regional metamorphic (dynamothermal)</li></ul><li>Hybrid</li><ul class="articlebody"><li>Metasomatic</li><li>Migmatitic</li></ul></ul>
Industry:Science
A relatively complex response pattern which is usually present in one or both sexes of a given species. These responses have a genetic basis, are essentially unlearned, and are generally adaptive.
Industry:Science
A relatively highly unsaturated oil which, on exposure to air, is oxidized and polymerized to form a hard, dry film. Vegetable and fish oils are classified as nondrying, semidrying, or drying, according to their ease of autoxidation and polymerization. Due to their film-forming properties, drying oils are used in paints, inks, and varnishes. The reactivity of drying oils with oxygen results from the presence of diallylic groups (that is, two double bonds separated by methylene groups, –CH=CHCH<sub>2</sub>CH=CH–) or conjugated double bonds (two carbon-carbon double bonds separated by a single bond). The number of diallylic groups <i>fn</i> per molecule is correlated with the oils' drying nature. Oils with <i>fn</i> greater than 2.2 are drying oils; those below 2.2 are semidrying to nondrying. The <b>table</b> shows the percentage of saturated and unsaturated fatty acids and the <i>fn</i> for some drying oils. These oils vary considerably by source and harvest time (see “Sunflower” in the table).
Industry:Science
A relatively large and diverse class of algae in the chlorophyll <i>a</i>–<i>c</i> phyletic line (Chromophycota). In protozoological classification, these organisms constitute an order, Chrysomonadida, of the class Phytomastigophora. Some workers align Chrysophyceae (golden or golden-brown algae) with Bacillariophyceae (diatoms) and Xanthophyceae (yellow-green algae) in the division Chrysophyta.
Industry:Science
A relatively large celestial body moving in orbit around a star, in particular the Sun.
Industry:Science
A relatively large crystal embedded in a finer-grained or glassy igneous rock. The presence of phenocrysts gives the rock a porphyritic texture (see <b>illustration</b>). Phenocrysts are represented most commonly by feldspar, quartz, biotite, hornblende, pyroxene, and olivine. Strictly speaking, phenocrysts crystallize from molten rock material (lava or magma). They commonly represent an earlier and slower stage of crystallization than does the matrix in which they are embedded. Phenocrysts are to be distinguished from certain relatively large crystals (porphyroblasts) which develop late in solid rock as the result of metamorphism or metasomatism. If the origin of a large crystal is in question, the nongenetic term megacryst should be used.
Industry:Science
A relatively large crystal formed in a metamorphic rock. The presence of abundant porphyroblasts gives the rock a porphyroblastic texture. Minerals found commonly as porphyroblasts include biotite, garnet, chloritoid, staurolite, kyanite, sillimanite, andalusite, cordierite, and feldspar.
Industry:Science
A relatively large, compact, bilobed, secretory organ located at the base of the tail (uropygium) of most birds having a keeled sternum. It is known also as the preen, oil, or scent gland. This is the only true skin gland possessed by this class of vertebrates. The gland develops from a pair of invaginations of the dorsal ectoderm on each side of the free coccygeal vertebrae, giving rise to numerous secretory tubules surrounded by a sheath of connective tissue of mesodermal origin. Experiments with duck embryos have shown that formation of the gland is dependent upon a specific action of the subjacent mesoderm on the overlying ectoderm. Implanted mesoderm from other body regions failed to induce a gland-forming response in the ectoderm.
Industry:Science
A relatively narrow, fast-moving wind current flanked by more slowly moving currents. Jet streams are observed principally in the zone of prevailing westerlies above the lower troposphere and in most cases reach maximum intensity, with regard both to speed and to concentration, near the tropopause. At a given time, the position and intensity of the jet stream may significantly influence aircraft operations because of the great speed of the wind at the jet core and the rapid spatial variation of wind speed in its vicinity. Lying in the zone of maximum temperature contrast between cold air masses to the north and warm air masses to the south, the position of the jet stream on a given day usually coincides in part with the regions of greatest storminess in the lower troposphere, though portions of the jet stream occur over regions which are entirely devoid of cloud. The jet stream is often called the polar jet, because of the importance of cold, polar air. The subtropical jet is not associated with surface temperature contrasts, like the polar jet. Maxima in wind speed within the jet stream are called jet streaks.
Industry:Science
