- 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.
Modern product development faces many challenges, including competitive forces from the global marketplace, highly constrained resources, and the need to keep pace with rapid technological change. A common response to the challenges is a formal process improvement program to ensure that product development processes are continuously improved in order to maximize both efficiency and effectiveness. At least six categories of such process improvement methodologies are in wide use today. Each category takes a unique perspective and includes specific methodologies that are applied to improve the product development processes. Contemporary improvement programs most often invoke two or more methodologies and are customized to the individual business culture and needs.
Industry:Science
Semiconductor devices used for the detection, generation, amplification, and control of electromagnetic radiation with wavelengths from 30 cm to 1 mm (frequencies from 1 to 300 GHz). Since 1985, the number and variety of microwave semiconductor devices, used for wireless and satellite communication and optoelectronics, have increased as new techniques, materials, and concepts have been developed and applied. Passive microwave devices, such as <i>pn</i> and PIN junctions, Schottky barrier diodes, and varactors, are primarily used for detecting, mixing, modulating, or controlling microwave signals. Step-recovery diodes, transistors, tunnel diodes, and transferred electron devices (TEDs) are active microwave devices that generate power or amplify microwave signals.
Industry:Science
Much of chemistry is explainable in terms of the structures of chemical compounds. The understanding of the structures of chemical compounds hinges very strongly on the understanding of the electronic configurations of the elements. The union of atoms, and therefore the formation of compounds from the elements, is associated with interactions among the extranuclear electrons of the individual atoms. Electronic interactions among atoms may occur in either of two ways: Electrons may be transferred from one atom to another, or they may be shared by two (or more) atoms. The first type of interaction is called electrovalence and results in the formation of electrically charged monatomic ions. The second, covalence, leads to the formation of molecules and complex ions.
Industry:Science
Nuclei with ratios of neutron number <i>N</i> to proton number <i>Z</i> much larger or much smaller than those of nuclei found in nature. Studies of nuclear matter under extreme conditions, in which the nuclei are quite different in some way from those found in nature, are at the forefront of nuclear research. Such extreme conditions include nuclei at high temperature and at high density (several times normal nuclear density), as well as those with larger or smaller <i>N</i>/<i>Z</i> ratios. The <i>N</i>/<i>Z</i> ratio depends on the nature of the attractive nuclear force that binds the protons and neutrons in the nucleus and its competition and complex interplay with the disruptive Coulomb or electrical force that pushes the positively charged protons apart.
Industry:Science
Ingredients added to food to provide all or a part of the flavor. Spices, a unique category of flavorings which are given preferred legal status because of the long history of their use in foods, are pungent or aromatic substances of vegetable origin used in foods at levels that yield no significant nutritive value. Flavor is the perception of those characteristics of a substance taken orally that affect the senses of taste and olfaction. The term flavoring refers to a substance which may be a single chemical species or a blend of natural or synthetic chemicals whose primary purpose is to provide all or part of the particular flavor effect to any food or other product taken orally. Flavorings are categorized by source: animal, vegetable, mineral, and synthetic.
Industry:Science
Mineral extraction in the Arctic, or other frozen regions, presents tremendous technical challenges to natural resource industries. There is good potential for finding economically attractive mineral deposits within the largely unexplored arctic-shield-type geology. Shields, also known as cratons, are large exposed areas of the oldest rocks on Earth and occur on all continents. Because of their age and the changes due to faulting, volcanism, metamorphism, and erosion, which have taken place through hundreds of millions of years, shields are favorable areas for mineral deposits. Similarly, offshore sedimentary basins offer the prospect of significant petroleum reserves. The challenges to the resource industry are sociological, environmental, economic, and technical.
Industry:Science
One of the three fundamental particles that transmit the weak force. (An example of a weak interaction process is nuclear beta decay.) These elementary particles—the <i>W<sup>+</sup></i>, <i>W<sup>−</sup></i>, and <i>Z</i><sup>0</sup> particles—were discovered in 1983 in very high energy proton-antiproton collisions. It is through the exchange of <i>W</i> and <i>Z</i> bosons that two particles interact weakly, just as it is through the exchange of photons that two charged particles interact electromagnetically. The intermediate vector bosons were postulated to exist in the 1960s; however, their large masses prevented their production and study at accelerators until 1983. Their discovery was a key step toward unification of the weak and electromagnetic interactions.
Industry:Science
One of two or more atoms which display a constant difference <i>A</i> – <i>Z</i> between their mass number <i>A</i> and their atomic number <i>Z</i>. Thus, despite differences in the total number of nuclear constituents, the numbers of neutrons in the nuclei of isotones are the same. The numbers of naturally occurring isotones provide useful evidence concerning the stability of particular neutron configurations. For example, the relatively large number (six and seven, respectively) of naturally occurring 50- and 82-neutron isotones suggests that these nuclear configurations are especially stable. On the other hand, from the fact that most atoms with odd numbers of neutrons are anisotonic, one may conclude that odd-neutron configurations are relatively unstable.
Industry:Science
Procedures for establishing environmentally acceptable end points for environmental cleanups include consideration of local, regional, or state background levels, waste or material-specific criteria or guidelines, risk-based generic state or federal limits, and site-specific target levels. Risk factors typically considered in developing any environmental cleanup standard or criterion have included land use and exposure to human, animal, or plant populations. However, there is evidence suggesting that a contaminant present in the subsurface or in sediments may not necessarily pose a risk to human health or the environment. Sorption is an important physical-chemical process governing the behavior of organic and inorganic contaminants and, thus, their bioavailability.
Industry:Science
Small, enigmatic structures which originate as terminal outpocketings from each side of the embryonic pharynx. They occur only in vertebrates, where they are almost universal but difficult to homologize. They probably represent an expression of continued growth activity caudally, associated with pouch- or gill-forming potentialities of foregut entoderm. They are usually bilateral in mammals. The last (and sometimes next to last) “true” pharyngeal pouch and ultimobranchial primordium often unite to form a combined entity known as a caudal pharyngeal complex. During development in humans, the ultimobranchial bodies may be intimately related to the third, as well as the fourth, pharyngeal pouch. Here, as in most mammals, this complex would be the fourth or last.
Industry:Science
