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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 law of electromagnetism which states that, whenever there is an induced electromotive force (emf) in a conductor, it is always in such a direction that the current it would produce would oppose the change which causes the induced emf. If the change is the motion of a conductor through a magnetic field, as in the <b>illustration</b>, the induced current must be in such a direction as to produce a force opposing the motion. If the change causing the emf is a change of flux threading a coil, the induced current must produce a flux in such a direction as to oppose the change. That is, if the change is an increase of flux, the flux due to the induced current must be opposite in direction to the increasing flux. If the change is a decrease in flux, the induced current must produce flux in the same direction as the decreasing flux.
Industry:Science
A law of gases which states that at constant temperature the volume of a gas varies inversely with its pressure. This law, formulated by Robert Boyle (1627–1691), can also be stated thus: The product of the volume of a gas times the pressure exerted on it is a constant at a fixed temperature. The relation is approximately true for most gases, but is not followed at high pressures. The phenomenon was discovered independently by Edme Mariotte about 1650 and is known in Europe as Mariotte's law.
Industry:Science
A law of physics which gives the spectral energy distribution of the heat radiation emitted from a so-called blackbody at any temperature. Discovered by Max Planck early in the twentieth century, this law laid the foundation for the advent of the quantum theory because it was the first physical law to postulate that electromagnetic energy exists in discrete bundles, or quanta.
Industry:Science
A law of physics which states that a confined fluid transmits externally applied pressure uniformly in all directions. Blaise Pascal, using the mercury-column barometer of Evangelista Torricelli, demonstrated the decrease in atmospheric pressure with increasing height and determined that atmospheric force at a point exerted equal pressure in all directions. More exactly, in a static fluid, force is transmitted at the velocity of sound throughout the fluid. The force acts normal to any surface. This natural phenomenon is the basis of the pneumatic tire, balloon, hydraulic jack, and related devices.
Industry:Science
A law of physics which states that the magnetic flux density (magnetic induction) near a long, straight conductor is directly proportional to the current in the conductor and inversely proportional to the distance from the conductor. There is also a law in fluid dynamics bearing this name; it is concerned with vortex motion, and bears a close analogy to the law discussed in the present article.
Industry:Science
A layer of organisms in the sea which causes sound to scatter and returns echoes. Recordings by sonic devices of echoes from sound scatterers indicate that the scattering organisms are arranged in approximately horizontal layers in the water, usually well above the bottom. The layers are found in both shallow and deep water.
Industry:Science
A layer within the Earth's atmosphere that extends from about 50 to 85 km (31 to 53 mi) above the surface. The mesosphere is predominantly characterized by its thermal structure. On average, mesospheric temperature decreases with increasing height.
Industry:Science
A lead systems integrator (LSI) is an organization (or set of organizations) that has been tasked to oversee the development and integration of system components for either a large, complex system or a system-of-systems (SoS). These large, complex systems and systems-of-systems are often referred to as “systems-of-interest."
Industry:Science
A learned response performed by a trained animal to a signal that was previously associated with an event of consequence for that animal. Conditioned reflex (CR) was first used by the Russian physiologist I. P. Pavlov to denote the criterion measure of a behavioral element of learning, that is, a new association between the signal and the consequential event, referred to as the conditioned stimulus (CS) and unconditioned stimulus (US), respectively. In Pavlov's classic experiment, the conditioned stimulus was a bell and the unconditioned stimulus was sour fluid delivered into the mouth of a dog restrained by harness; the conditioned stimulus was followed by the unconditioned stimulus regardless of the dog's response. After training, the conditioned reflex was manifested when the dog salivated to the sound of the bell.
Industry:Science
A lens or optical system which offers to the eye the image originating from another system (the objective), at a suitable viewing distance. The image can be virtual.
Industry:Science
