- 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.
Concrete that is cast into forms and cured at a location other than its final position in a structure. Products that are commonly fabricated in this manner include beams and joists, slab units, wall panels, and utility items such as pipe sections and access holes for workers. Cast stone that is made to simulate cut and dressed stone is a form of precast. Concrete block is also sometimes considered a form of precast. Precast concrete can be unreinforced or reinforced, and prestressed by the pretensioning or posttensioning method. Precast concrete is used with cast-in-place, structural steel, or load-bearing masonry construction. Field connections are more critical for precast than for monolithic cast-in-place concrete, because the connections must provide structural continuity and load transfer between elements.
Industry:Science
Depression refers to a set of prevalent, extremely debilitating disorders that can be characterized by a triad of symptoms: extreme anhedonia (complete loss of pleasure from previously pleasurable activities), depressed mood, and low energy. Other cognitive symptoms (for example, pessimistic thoughts, feelings of guilt, low self-esteem, and suicidal ideations) and somatic symptoms (for example, sleep and psychomotor disturbances, and food-intake and body-weight dysregulation) are also often present. Unipolar major depression (unipolar refers to the presence of one pole or one extreme of mood, namely depressed mood) is the leading cause of disability worldwide and is associated with a high mortality due to suicide and increases in mortality in comorbid somatic disorders such as cardiovascular disorders or cancer.
Industry:Science
Composites are the fastest-growing area of wood products for housing and industrial applications. Most wood composites are a substitute for a solid wood product. The raw materials for wood composites include a wood base (fiber, particle, strand, or strip) combined with various adhesives, waxes, or other nonwood materials to produce a panel or lumber product. Both wood composite panels and composite lumber products can be used for structural or nonstructural purposes, depending upon the end use for which they are manufactured. Structural applications are those with specific strength requirements, such as wall sheathing, framing, decking, and flooring. Nonstructural applications involve the use of wood composites as substrates for decorative overlays, moldings, window and door parts, and other nonload-bearing uses.
Industry:Science
Determination of the relative or absolute age of materials or objects by measurement of the degree of racemization of the amino acids present. With the exception of glycine, the amino acids found in proteins can exist in two isomeric forms called <small>d</small>- and <small>l</small>-enantiomers. Although the enantiomers of an amino acid rotate plane-polarized light in equal but opposite directions, their other chemical and physical properties are identical. Amino acid handedness or homochirality is one of the most distinctive features of terrestrial life. It was discovered by L. Pasteur around 1850 that only <small>l</small>-amino acids are generally found in living organisms, but scientists still have not formulated a convincing reason to explain why life on Earth is based on only <small>l</small>-amino acids.
Industry:Science
Complex systems in which computers play a major role. While complex physical systems and sophisticated software systems can help people to lead healthier and more enjoyable lives, reliance on these systems can also result in loss of money, time, and life when these systems fail. Much of the complexity of these systems is due to integration of information technology into physical and human activities. Such integration dramatically increases the interdependencies among components, people, and processes, and generates complex dynamics not taken into account in systems of previous generations. Engineers with detailed understanding of the application domain and computer electronics, software, human factors, and communication are needed to provide a holistic approach to system development so that disasters do not occur.
Industry:Science
Any of the deciduous shrubs and trees of the genus <i>Alnus</i> in the birch family (Betulaceae). There are about 30 species, 10 in the United States, widespread in cool north temperate regions, and southward in the Andes of South America. They have a smooth gray bark, elliptical or ovate saw-toothed leaves in three rows, male flowers in long catkins mostly in early spring, and clusters of several dry hard ellipsoid blackish fruits 0.5–1 in. (1.2–2.5 cm) long. The fruits are conelike and present throughout the year.
Alders are common in wet soils, such as stream borders. They often form thickets even beyond treelines and are pioneers on bare areas such as landslides, roadsides, and after fire or logging. As in legumes, the roots bear swellings or nodules containing nitrogen-fixing bacteria which enrich the soil.
Industry:Science
La combinación de ítems culturales existentes para formar algo que no existía previamente.
Industry:Sociology
Fungi are organisms that live entirely by the absorption of nutrients from either living or dead organisms. They represent an important component of the ecosystem, where they function as decomposers and in the recycling of carbon and minerals. Thus, fungi played a pivotal role in the establishment of early terrestrial ecosystems. The oldest evidence of life on Earth is septate filaments, like those of certain cyanobacteria, dated at approximately 3.6 billion years.
Evidence of the oldest terrestrial fungi includes hyphae approximately 430 million years old, but it is impossible to determine how these fungi interacted with other organisms in the ancient ecosystem. The oldest fossil fungi in which interactions can be accurately documented are from the Lower Devonian Rhynie Chert, dated at approximately 400 million years.
Industry:Science
Depression is not a normal consequence of growing old. It is, instead, a treatable illness, a source of excess disability, and the major cause of suicide in the elderly. Depression occurs in 2–3% of persons aged 60 and above residing in communities, 8–10% of elderly patients attending general medical clinics, and 20% or more of elderly patients in acute medical hospitals or long-term care facilities.
The World Health Organization has estimated that depression and suicide constitute the fourth leading contributor to the global burden of illness-related disability and death. It expects that the importance of depression as a source of disability and impaired quality of life will increase in the next 10 years, especially in the developed economies, because of the high proportion of elderly persons in the general population.
Industry:Science
In a dynamic or kinetic sense, chemical equilibrium is a condition in which a chemical reaction is occurring at equal rates in its forward and reverse directions, so that the concentrations of the reactant and product substances do not change with time. In a thermodynamic sense, it is the condition in which there is no tendency for the composition of the system to change.
From the viewpoint of statistical mechanics, the equilibrium state places the system in a condition of maximum freedom (or minimum restraint) compatible with the energy, volume, and composition of the system. The statistical approach has been merged with thermodynamics into a field called statistical thermodynamics; this merger has been of immense value for its intellectual stimulus, as well as for its practical contributions to the study of equilibria.
Industry:Science
