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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 physical factor which is significant in biology because, in many biological actions of high-energy radiations, linear energy transfer (LET) strongly and characteristically modifies the quantitative relations between dose and effect.
Industry:Science
A physical method of separation in which the components of a mixture of substances are separated from each other by differences in their distribution between two phases, one (stationary phase) is stationary and the other (mobile phase) moves through the stationary phase in a definite direction. The substances must interact with the stationary phase to be retained and separated by it.
Industry:Science
A physical stochastic process is any process governed by probabilistic laws. Examples are (1) development of a population as controlled by mendelian genetics; (2) brownian motion of microscopic particles subjected to molecular impacts or, on a different scale, the motion of stars in space; (3) succession of plays in a gambling house; and (4) passage of cars by a specified highway point.
Industry:Science
A physical theory usually involves the attempt to explain a certain class of physical phenomena by deducing them as necessary consequences of other phenomena regarded as more primitive and less in need of explanation. These more primitive phenomena may at the time the theory is formulated be undiscovered, so that part of the proof of the correctness of the theory consists in demonstrating the existence of the unknown assumed primitive phenomena. A classic example is the kinetic theory of gases, in which the pressure of a gas is explained as arising from the kinetic reactions of colliding molecules, the reality of which was established only later by the discovery of phenomena such as the brownian fluctuations.
Industry:Science
A physics research facility developed to detect cosmic gravitational waves and to measure these waves for scientific research. It consists of two installations within the continental United States, located in the states of Washington and Louisiana, operated in unison as a single observatory. Funded by the National Science Foundation (NSF), LIGO was designed and constructed by a team of scientists from the California Institute of Technology and the Massachusetts Institute of Technology, and by industrial contractors. Construction of the facilities was completed in 1999, and operation of the detectors began in 2001. LIGO is the leading member in a developing global network of gravitational-wave observatories.
Industry:Science
A physiologically interactive system within which growth, adaptation, species composition, nutrient cycling, biological productivity, and energy flows among inland aquatic microbial, plant, and animal communities are integrated with the environment. These inland waters include lakes, reservoirs, rivers, streams, and wetlands. The discipline termed limnology evaluates how these relationships regulate, and are regulated by, natural and anthropogenic variations in the physical, chemical, and biotic environments. The standing-water (lentic) lake or reservoir ecosystem is intimately coupled with the land in its surrounding drainage area and with its running (lotic) waters that change chemical components from the land as they are transported to the lake. Often the land-water interface supports productive wetlands, that is, areas of shallow water often found at the edge of lakes (littoral zone) or along rivers (floodplain).
Industry:Science
A pictorial representation of elementary particles and their interactions. The diagrams show the paths of particles in space and time as lines, and the interactions between the particles as points where the lines meet.
Industry:Science
A piece of electronic test equipment that delivers a sinusoidal output of accurately calibrated frequency. The frequency may be anywhere from audio to microwave, depending upon the intended use of the instrument. The frequency and the amplitude are adjustable over a wide range. The oscillator must have excellent frequency stability, and its amplitude must remain constant over the tuning range.
Industry:Science
A piece of rigid material whose two major surfaces make an acute angle θ. It is closely related to the inclined plane and is used to multiply the applied force and to change the direction in which it acts.
Industry:Science
A pigment that controls most photomorphogenic responses in higher plants. As a result of the dependence of plants on the energy of sunlight and their sessile habit, mechanisms have evolved that allow them to adapt their growth and development to more efficiently seek and capture light and to tailor their life cycle to the climatic seasons. These mechanisms enable the plant to sense not only the presence of light but also its intensity, direction, duration, and spectral quality, which suggests a form of color vision. Plants thus regulate important developmental processes such as seed germination, growth direction, growth rate, chloroplast development, pigmentation, flowering, and senescence, collectively termed photomorphogenesis.
Industry:Science
