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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 phaneritic (visibly crystalline) plutonic rock with granular texture composed largely of alkali feldspar (orthoclase, microcline, usually perthitic) with subordinate plagioclase (oligoclase) and dark-colored (mafic) minerals (biotite, amphibole, and pyroxene). If sodic plagioclase (oligoclase or andesine) exceeds the quantity of alkali feldspar, the rock is called monzonite. Monzonites are generally light to medium gray, but syenites are found in a wide variety of colors (gray, green, pink, red), some of which make the material ideal for use as ornamental stone.
Industry:Science
A phaneritic (visibly crystallized) plutonic rock having intermediate SiO<sub>2</sub> content (53–66%), composed mainly of plagioclase (oligoclase or andesine) and one or more ferromagnesian minerals (hornblende, biotite, or pyroxene), and having a granular texture. Diorite is the plutonic equivalent of andesite (a volcanic rock). This dark gray rock is used occasionally as a building stone and is known commercially as black granite. For a general discussion of textural, structural, and compositional differences
Industry:Science
A phase of matter characterized by relatively low density, high fluidity, and lack of rigidity. A gas expands readily to fill any containing vessel. Usually a small change of pressure or temperature produces a large change in the volume of the gas. The equation of state describes the relation between the pressure, volume, and temperature of the gas. In contrast to a crystal, the molecules in a gas have no long-range order.
Industry:Science
A phase-change process in which vapor converts into liquid when the temperature of the vapor is reduced below the saturation temperature corresponding to the pressure in the vapor. For a pure vapor this pressure is the total pressure, whereas in a mixture of a vapor and a noncondensable gas it is the partial pressure of the vapor. Sustaining the process of condensation on a cold surface in a steady state requires cooling of the surface by external means. Condensation is an efficient heat transfer process and is utilized in various industrial applications. Condensation of vapor on a cold surface can be classified as film-wise or drop-wise. Direct-contact condensation refers to condensation of vapor (bubbles or a vapor stream) in a liquid or condensation on liquid droplets entrained in the vapor. If vapor temperature falls below its saturation temperature, condensation can occur in the bulk vapor. This phenomenon is called homogeneous condensation (formation of fog) and is facilitated by foreign particles such as dust.
Industry:Science
A phenomenon among some salamanders, in which larvae of large size, while still retaining the gills and other larval features, become sexually mature, mate, and produce fertile eggs. In certain lakes of Mexico, only the neotenous larvae are present and are called axolotls. Neoteny occurs in certain species of the family Ambystomidae, especially in <i>Ambystoma tigrinum</i> of some localities, and commonly in the large <i>Dicamptodon ensatus</i> of the Pacific Coast. It also occurs in some Texas and Oklahoma species of <i>Eurycea</i>. Neotenous larvae of <i>A</i>. <i>tigrinum</i> can be made to metamorphose to adult form if treated with thyroid extract.
Industry:Science
A phenomenon by which light from the stars, as it passes through fluctuations in the Earth's atmosphere, is rapidly modulated and redirected to make the starlight appear to flicker. Although it is familiar to those who have looked with the unaided eye at the night sky, the twinkling phenomenon affects all wavelengths that manage to penetrate the Earth's atmosphere, from the visible to the radio wavelengths. At visible wavelengths, atmospheric fluctuations are caused predominantly by temperature irregularities along the line of sight. Minor contributions are made by irregularities in atmospheric density and in water vapor content. All such irregularities introduce slight changes in the index of refraction of air, and these changes affect light waves in two ways: they modulate the intensity of the light, and they deflect the light waves in one direction and then another. An analogous phenomenon is often observed when light grazes across the surface of a hot highway: light is bent and distorted by pockets of hot air rising over the pavement's surface. At radio wavelengths, electron density irregularities in the ionosphere modulate and redirect radio waves.
Industry:Science
A phenomenon discovered in 1834 by J. C. A. Peltier, who found that at the junction of two dissimilar metals carrying a small current the temperature rises or falls, depending upon the direction of the current. Many different pairs of metals were investigated; bismuth and copper were among the first. The temperature rises at a junction where the flow of positive charge is from Cu to Bi and falls where the flow is from Bi to Cu. A reversible output of heat occurs at the first-named junction and a reversible intake at the second. In view of the experiments of Quintus Icilius (1853), which established that the rate of intake or output of heat is proportional to the magnitude of the current, it can be shown that an electromotive force resides at a Cu-Bi junction, directed from Bi to Cu. Electromotive forces of this type are called Peltier emf's.
Industry:Science
A phenomenon discovered in 1854 by William Thomson (Lord Kelvin). He found that there occurs a reversible transverse heat flow into or out of a conductor of a particular metal, the direction depending upon whether a longitudinal electric current flows from colder to warmer metal or from warmer to colder. Any temperature gradient previously existing in the conductor is thus modified if a current is turned on. The Thomson effect does not occur in a current-carrying conductor which is initially at uniform tempera- ture.
Industry:Science
A phenomenon exhibited by certain resonant optical structures whereby it is possible to have two stable steady transmission states for the device, depending upon the history of the input. Such a bistable device may be useful for optical computing elements because of its memory characteristics. The bistability can result from the intrinsic properties of the optical device or from some external feedback such as an electrical voltage supplied by another device. This second type, extrinsic or hybrid optical bistability, is not true optical bistability.
Industry:Science
A phenomenon exhibited by the magnetic spin systems of certain atoms whereby the spin systems absorb energy at specific (resonant) frequencies when subjected to alternating magnetic fields. The magnetic fields must alternate in synchronism with natural frequencies of the magnetic system. In most cases the natural frequency is that of precession of the bulk magnetic moment <b>M</b> of constituent atoms or nuclei about some magnetic field <b>H</b>. Because the natural frequencies are highly specific as to their origin (nuclear magnetism, electron spin magnetism, and so on), the resonant method makes possible the selective study of particular features of interest. For example, it is possible to study weak nuclear magnetism unmasked by the much larger electronic paramagnetism or diamagnetism which usually accompanies it.
Industry:Science
