- 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 plastic mixture of solids and water that sets to a hard, coherent solid and that is used to line the interiors of buildings. A similar material of different composition, used to line the exteriors of buildings, is known is stucco. The term plaster is also used in the industry to designate plaster of paris.
Industry:Science
A platform or enclosure that is raised and lowered in a vertical hoistway to transport freight or people. The term elevator can also encompass all of the hoisting equipment, motor, cables, and accessories (see <b>illus.</b>).
Industry:Science
A point on a line parallel to the axis of a beam through which any transverse force must be applied to avoid twisting of the section. A beam section will rotate when the resultant of the internal shearing forces is not collinear with the externally applied force. The shear center may be determined by locating the line of action of the resultant of the internal shear forces. A rolled wide flange beam section has two axes of symmetry, and therefore the shear center coincides with the geometric center or centroid of the section. When such a beam member is loaded transversely in the plane of the axes, it will bend without twisting.
Industry:Science
A polyether derived from aldehydes (R=CH<sub>2</sub> or CHR′) or ketones (R=C(R′R′)) and containing –O–R–O– groups in the main chain. Of the many possible polyacetals, the most common is a polymer or copolymer of formaldehyde, polyoxymethylene (–O–CH<sub>2</sub>–)<sub><i>n</i></sub>. While the substance paraformaldehyde contains oligomers or low-molecular-weight polyoxymethylenes (<i>n</i> very small), high-molecular-weight, crystalline polyoxymethylenes constitute an important class of engineering plastics that, in commerce, is often simply referred to as polyacetal. Cellulose and its derivatives also have a polyacetal structure. For discussion of other polyethers and polymers containing acetal side groups.
Industry:Science
A polyglucose biopolymer characterized by preponderance of α-1,6 linkage, and generally produced by enzymes from certain strains of <i>Leuconostoc</i> or <i>Streptococcus</i>. The chemical properties may be modified chemically for specific usages. While formerly its principal utility was as blood plasma substitute, dextran is also employed as packing material in column chromatography and as pharmaceutical agents; its average molecular weight determines usage to a great extent. Dextran's chemical and physical properties depend upon the strain of microorganism employed and the environmental conditions imposed upon the bacterium during growth, or the reaction conditions where an enzymatic method of dextran production is employed. <i>Leuconostoc</i> and <i>Streptococcus</i> species primarily convert sucrose to dextran and fructose. <i>Acetobacter</i> species convert dextrin to dextran; the α-1,4 linkage is converted to an α-1,6 linkage.
Industry:Science
A polyhedron of which two faces are congruent polygons in parallel planes, and the other faces are parallelograms (see <b>illus</b>.). The bases <i>B</i> are the congruent polygons; the lateral faces are the parallelograms; the lateral edges are the edges not lying in the bases; and the perpendicular distance between the bases is the altitude <i>l</i>. Sections parallel to the bases are congruent to the bases. A prism is a right prism if its lateral edges are perpendicular to the bases; an oblique prism otherwise. A prism is called a triangular prism if its bases are triangles; a pentagonal prism if its bases are pentagons; and a parallelepiped if its bases are parallelograms. The volume of any prism is equal to the area of its base times its altitude (<i>V</i> = <i>B</i><i>h</i>).
Industry:Science
A polymer found extensively in the cell walls of all woody plants; is one of the most abundant natural polymers. Lignin, which constitutes one-fourth to one-third of the total dry weight of trees, combines with hemicellulose materials to help bind the cells together and direct water flow.
Industry:Science
A polypeptide hormone synthesized and secreted by the endodermally derived reticular cells of the thymus gland.
Industry:Science
A polyphyletic class of Eumycota in the subdivision Zygomycotina, containing the orders Amoebidiales Asellariales, Eccrinales, and Harpellales. These orders are grouped together because they usually exist only as commensals in the mid- and hindgut of arthropods (<i>Amoebidium parasiticum</i> can be found on the outside of its hosts).
Industry:Science
A polysaccharide that is a major constituent of the cell walls of certain red algae (Rhodophyceae), especially members of the families Gigartinaceae, Hypneaceae, Phyllophoraceae, and Solieriaceae. Extracted for its suspending, emulsifying, stabilizing, and gelling properties, it is one of three algal polysaccharides of major economic importance, the others being agar and alginate.
Industry:Science
