- 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.
Decay of the components of wood. Despite its highly integrated matrix of cellulose, hemicellulose, and lignin, which gives wood superior strength properties and a marked resistance to chemical and microbial attack, a variety of organisms and processes are capable of degrading wood. The decay process is a continuum, often involving a number of organisms over many years. Wood degrading agents are both biotic and abiotic, and include heat, strong acids or bases, organic chemicals, mechanical wear, and sunlight (uv degradation).
Industry:Science
Crustaceans, in particular larger crustaceans such as crayfish and lobsters, are among the animal models used to study olfaction, the sense of smell. Although crustaceans as a group are largely aquatic animals, and have their olfactory receptor neurons packaged in sensilla (hairlike sensory structures), the crustacean olfactory organ is functionally similar to noses of other animals and has contributed to common understanding of the sense of smell. The olfactory organ or “nose” of crustaceans has been especially well studied.
Industry:Science
In describing an engine or gas compressor, the ratio of volume of working substance actually admitted, measured at specified temperature and pressure, to the full piston displacement volume. For a liquid-fuel engine, such as a diesel engine, volumetric efficiency is the ratio of volume of air drawn into a cylinder to the piston displacement. For a gas-fuel engine, such as a gasoline engine with carburetor, throttle body, or port injection, volumetric efficiency is based on the charge of fuel and air drawn into the cylinder.
Industry:Science
Finding the age of rocks based on the presence of naturally occurring long-lived radioactive isotopes of several elements in certain minerals and rocks. Measurements of rock ages have enabled geologists to reconstruct the geologic history of the Earth from the time of its formation 4.6 × 10<sup>9</sup> years ago to the present. Age determinations of rocks from the Moon have also contributed to knowledge of the history of the Moon, and may someday be used to study the history of Mars and of other bodies within the solar system.
Industry:Science
For the purposes of thermodynamics, it is convenient to define all energy while in transit, but unassociated with matter, as either heat or work. Heat is that form of energy in transit due to a temperature difference between the source from which the energy is coming and the sink toward which the energy is going. The energy is not called heat before it starts to flow or after it has ceased to flow. A hot object does contain energy, but calling this energy heat as it resides in the hot object can lead to widespread confusion.
Industry:Science
Defoliants are chemicals that cause leaves to drop from plants; defoliation facilitates harvesting. Desiccants are chemicals that kill leaves of plants; the leaves may either drop off or remain attached; in the harvesting process the leaves are usually shattered and blown away from the harvested material. Defoliants are desirable for use on cotton plants because dry leaves are difficult to remove from the cotton fibers. Desiccants are used on many seed crops to hasten harvest; the leaves are cleaned from the seed in harvesting.
Industry:Science
Any solid waste that is generated in the diagnosis, treatment, or immunization of human beings or animals, in research pertaining thereto, or in the production or testing of biologicals. Since the development of disposable medical products in the early 1960s, the issue of medical waste has confronted hospitals and regulators. Previously, reusable products included items such as linen, syringes, and bandages; they were sterilized or disinfected prior to reuse, and the principal waste product was limited to human pathological tissue.
Industry:Science
Fungi that form spores asexually (via mitosis) and that produce their spores externally on threadlike hyphae (as opposed to bearing them inside a fruiting body). In traditional taxonomy, Hyphomycetes was a formal class, but because this group is nonphylogenetic (it is composed of more than one evolutionary lineage), many mycologists now either attach a prefix, as in “form-class Hyphomycetes,” or use the term colloquially, as in “hyphomycetes.” The mitotic spores of hyphomycetes (as well as those of coelomycetes) are called conidia.
Industry:Science
Assembling an electronic circuit in the most convenient manner on a board or other flat surface, without regard for final locations of components, to prove the feasibility of the circuit and to facilitate changes when necessary. Standard breadboards for experimental work are made with mounting holes and terminals closely spaced at regular intervals, so that parts can be mounted and connected without drilling additional holes. Such breadboards are useful only for relatively simple circuits operating at audio or low radio frequencies.
Industry:Science
Despite limitations in analysis methodology, knowledge about the occurrence and significance of fungi in drinking water has increased considerably in recent decades, and fungi are now generally accepted as drinking-water contaminants. However, the relevance of water-borne fungi for water quality and human health is poorly understood, and reports of effective treatment and disinfection against fungi in water are few. The occurrence of fungi in drinking water may be regarded as a potential health risk for particular vulnerable groups.
Industry:Science
