- 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.
A device used to control the speed of a prime mover. A governor protects the prime mover from overspeeding and keeps the prime mover speed at or near the desired revolutions per minute. When a prime mover drives an alternator supplying electrical power at a given frequency, such as 60 Hz, a governor must be used to hold the prime mover at a speed that will yield this frequency. An unloaded engine will fly to pieces unless its speed is under governor control.
Industry:Science
A device used to detect and measure radiation characteristically emitted in atomic, molecular, or nuclear processes, including photons (light, including visible light, gamma rays, and x-rays), lightweight charged particles (electrons or positrons), nuclear constituents (neutrons, protons, and heavier ions), energetic neutral particles (fast-moving atoms, for example), and subnuclear constituents such as mesons. The device can also be known as a radiation detector. Since human senses generally do not respond to these types of radiation (with the obvious exception of visible light), detectors are essential tools for the discovery of radioactive minerals, for all studies of the structure of matter at the atomic, nuclear, and subnuclear levels, and for protection from the effects of radiation. They have also become important practical tools in the analysis of materials using the techniques of neutron activation and x-ray fluorescence analysis.
Industry:Science
A device used to measure the dose of ionizing radiation received by an individual. There are many types of dosimeters with varying characteristics and capabilities appropriate for different applications. They differ in sensitivity, energy range, and species of radiation to which they respond. Some can be read out directly by the wearer, while others must be sent to a specially equipped facility to determine the dose.
Industry:Science
A device used to move solids upward through a chamber or conduit. It is able to overcome the large dynamic forces at the base of a solids bed and cause the entire bed to move upward.
Industry:Science
A device used to remove liquid droplets or solid particles from a gas in which they are suspended. The process depends on two steps. In the first step the suspension passes through an electric discharge (corona discharge) area where ionization of the gas occurs. The ions produced collide with the suspended particles and confer on them an electric charge. The charged particles drift toward an electrode of opposite sign and are deposited on the electrode where their electric charge is neutralized. The phenomenon would be more correctly designated as electrodeposition from the gas phase. The practical aspects of the electrostatic precipitator were demonstrated in 1906 by F. G. Cottrell.
Industry:Science
A device used to transfer heat from a fluid flowing on one side of a barrier to another fluid (or fluids) flowing on the other side of the barrier.
Industry:Science
A device used to vaporize part or all of the solvent from a solution. The valuable product is usually either a solid or a concentrated solution of the solute. If a solid, the heat required for evaporation of the solvent must have been supplied to a suspension of the solid in the solution; otherwise the device would be classed as a drier. The vaporized solvent may be made up of several volatile components, but if any separation of these components is effected, the device is properly classed as a still or distillation column. When the valuable product is the vaporized solvent, an evaporator is sometimes mislabeled a still, such as water still, and sometimes is properly labeled, such as boiler-feedwater evaporator. In the great majority of evaporator installations, water is the solvent that is removed.
Industry:Science
A device which measures mechanical deformation. Normally it is attached to a structural element, and uses the change of electrical resistance of a wire or semiconductor under tension. Capacity, inductance, and reluctance are also used.
Industry:Science
A device which, in its simplest form, provides an output that corresponds to the number of pulses applied to its input.
Industry:Science
A device whose purpose is to ensure that the amplitude of a sensed variable (referred to as a signal) is constrained or limited to lie within prescribed maximum and minimum values. It is more properly termed an amplitude limiter, although convention usually dispenses with the important modifier. Also, unless specified otherwise, the limiting is applied to voltage.
Industry:Science
