- 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.
The technology concerned with the prediction of the optimum economic recovery of oil or gas from hydrocarbon-bearing reservoirs. It is an eclectic technology requiring coordinated application of many disciplines: physics, chemistry, mathematics, geology, and chemical engineering. Originally, the role of reservoir engineering was exclusively that of counting oil and natural gas reserves. The reserves—the amount of oil or gas that can be economically recovered from the reservoir—are a measure of the wealth available to the owner and operator. It is also necessary to know the reserves in order to make proper decisions concerning the viability of downstream pipeline, refining, and marketing facilities that will rely on the production as feedstocks.
Industry:Science
The pair of elastic, fibered bands inside the human larynx. The cords are covered with a mucous membrane and pass horizontally backward from the thyroid cartilage (Adam's apple) to insert on the smaller, paired arytenoid cartilages at the back of the larynx. The vocal cords act as sphincters for air regulation and may be vibrated to produce sounds. Separation, approximation, and alteration of tension are produced by action of laryngeal muscles acting on the pivoting arytenoids. Innervation is through branches of the vagus nerve. Vibration of the cords produces fundamental sounds and overtones. These can be modified by the strength of the air current, the size and shape of the glottis (the opening between the cords), and tension in the cords.
Industry:Science
The software component of a computer system that is responsible for managing and coordinating activities and sharing the resources of the computer. The operating system (OS) acts as a host for application programs that are run on the machine. (In computer jargon, application programs are said to run on top of the operating system.) As a host, one of the functions of an operating system is to handle the details of the hardware operation. This relieves application programs from having to manage these details and makes it easier to write applications. Almost all computers use an operating system, such as hand-held computers (including personal data assistants or PDAs), laptop and desktop computers, supercomputers, and even modern video game consoles.
Industry:Science
The organic materials produced by plants, such as leaves, roots, seeds, and stalks. In some cases, microbial and animal metabolic wastes are also considered biomass. The term “biomass” is intended to refer to materials that do not directly go into foods or consumer products but may have alternative industrial uses. Common sources of biomass are (1) agricultural wastes, such as corn stalks, straw, seed hulls, sugarcane leavings, bagasse, nutshells, and manure from cattle, poultry, and hogs; (2) wood materials, such as wood or bark, sawdust, timber slash, and mill scrap; (3) municipal waste, such as waste paper and yard clippings; and (4) energy crops, such as poplars, willows, switchgrass, alfalfa, prairie bluestem, corn (starch), and soybean (oil).
Industry:Science
The term automation originated during the 1950s to refer to automatic control of the manufacture of a product through a number of successive stages. It subsequently was expanded to mean the application of automatic control through the use of electronic or mechanical devices to replace human labor in any branch of industry or science. Replacing physical labor was of principal concern decades ago, but today, at least in the developed nations, the goal is to replace mental labor. Computers and the accompanying sensors that interpret inputs, record data, make decisions, or generate displays to give warnings or advice to humans are now also regarded as automation, though in the strict sense none of these latter functions may be complete automatic control.
Industry:Science
The study of the action of ionizing and nonionizing radiation on biological systems. Ionizing radiation includes highly energetic electromagnetic radiation (x-rays, gamma rays, or cosmic rays) and particulate radiation (alpha particles, beta particles, neutrons, or heavy charged ions). Nonionizing radiation includes ultraviolet radiation, microwaves, and extralow-frequency (ELF) electromagnetic radiation. These two types of radiation have different modes of action on biological material: ionizing radiation is sufficiently energetic to cause ionizations, whereas nonionizing radiation causes molecular excitations. In both cases, the result is that chemical bonds of molecules may be altered, causing mutations, cell death, or other biological changes.
Industry:Science
The process of introducing a microorganism or suspension of microorganism into a culture medium. The medium may be (1) a solution of nutrients required by the organism or a solution of nutrients plus agar; (2) a cell suspension (tissue culture); (3) embryonated egg culture; or (4) animals, for example, rat, mouse, guinea pig, hamster, monkey, birds, or human being. When animals are used, the purpose usually is the activation of the immunological defenses against the organism. This is a form of vaccination, and quite often the two terms are used interchangeably. Both constitute a means of producing an artificial but active immunity against specific organisms, although the length of time given by such protection may vary widely with different organisms.
Industry:Science
The quantum-mechanical description of matter aims to explain how diverse properties of materials arise from the mutual interactions of many atomic nuclei and their associated electrons. While a more or less complete theory of ordinary electrical conduction in metals was developed in the early part of the twentieth century, newer phenomena such as high-temperature superconductivity and ballistic conduction in carbon-based electronic devices challenge our basic understanding of condensed-matter physics. It is an important goal to understand the subtle interactions leading to these phenomena, and if possible to control them. Can these inherently quantum-mechanical behaviors be extended to room temperature? If so, remarkable applications could be envisioned.
Industry:Science
The living world comprises a dazzling variety of species. Explaining the origins of this diversity is a key goal of evolutionary biology. The process behind diversification is speciation, whereby a single species splits into two or more descendant species. But how can evolutionary biologists study a process that occurs over thousands to millions of years, when the fossil record is often too coarse to follow speciation in detail? The answer is to reconstruct phylogenetic trees, branching diagrams depicting the evolutionary relationships among living species. The growth of molecular phylogenetics, combined with new statistical methods for analyzing the resulting phylogenetic trees, is leading to new understanding of the patterns and processes of speciation.
Industry:Science
The sediment debris load of streams is a natural corollary to the degradation of the landscape by weathering and erosion. Eroded material reaches stream channels through rills and minor tributaries, being carried by the transporting power of running water and by mass movement, that is, by slippage, slides, or creep. The size represented may vary from clay to boulders. At any place in the stream system the material furnished from places upstream either is carried away or, if there is insufficient transporting ability, is accumulated as a depositional feature. The accumulation of deposited debris tends toward increased ease of movement, and this tends eventually to bring into balance the transporting ability of the stream and the debris load to be transported.
Industry:Science
