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  • accounts payable (finance)
    any amount owed by a company as the result of a purchase of goods or services from another company on a credit basis. Under a trade-credit arrangement, the purchasing company, after placing its order with the seller, receives the goods and an invoice denoting the price of the goods and the terms for payment. The purchasing firm does not send a trade acceptance or promissory note for payment but e...
  • accounts receivable (finance)
    any amount owed to a business by a customer as a result of a purchase of goods or services from it on a credit basis. The company making the sale does not receive an acceptance or promissory note (i.e., written orders or promises to pay) from the purchaser but merely enters the amount due as a current asset in its books. Accounts receivable constitute ...
  • Accra (Ghana)
    capital and largest city of Ghana, on the Gulf of Guinea (Atlantic Ocean). The city lies partly on a cliff, 25 to 40 feet (8 to 12 metres) high, and spreads northward over the undulating Accra plains. The area’s susceptibility to faulting is the cause of occasional earthquakes....
  • Accra Plains (region, Ghana)
    The southeastern corner of the country, between the Akwapim-Togo Ranges and the sea, consists of the gently rolling Accra Plains, which are underlain by some of the oldest Precambrian rocks known—mostly gneisses (coarse-grained rocks in which bands containing granular minerals alternate with bands containing micaceous minerals); in places they rise above the surface to form inselbergs......
  • accretion (cosmology)
    The Earth is thought to have accreted from a cloud of ionized particles around the Sun. This gaseous matter condensed into small particles that coalesced to form a protoplanet, which in turn grew by the gravitational attraction of more particulates. Some of these particles had compositions similar to that of carbonaceous chondrite meteorites, which may contain up to 20 percent water. Heating of......
  • accretion deposit (geophysics)
    Coral islands created by accretion have developed from rubbly reef rock broken off from the reef by storms and waves and mixed with finer reef detritus. The exceptional conditions of cyclonic storms are sometimes sufficient to create reef-top shoals in a single event. Other material accumulates by more regular methods such as normal currents and wave action. Beaches develop around the shoal,......
  • accretion disc (astronomy)
    ...a long time. The most probable hypothesis is that it was formed at the same time as the giant planets by the very process that accreted them. The Soviet astronomer Viktor S. Safronov developed this accretionary theory of the planetary system mathematically in 1972. According to his model, the planets originated from a disk or a ring of dust around the Sun, and cometary nuclei are nothing more.....
  • accretion disk (astronomy)
    ...a long time. The most probable hypothesis is that it was formed at the same time as the giant planets by the very process that accreted them. The Soviet astronomer Viktor S. Safronov developed this accretionary theory of the planetary system mathematically in 1972. According to his model, the planets originated from a disk or a ring of dust around the Sun, and cometary nuclei are nothing more.....
  • accretion theory (geology)
    ...that most continental shields are bordered by belts of folded rocks of post-Precambrian age. One school of thought holds that Earth history can be interpreted in terms of the concept of continental accretion—i.e., that belts of successively younger rocks have undergone intense deformation in episodes of mountain building and have become welded onto the borders of the preexisting.....
  • accretionary lapillus (volcanism)
    ...32 mm (0.16 and 1.26 inches) that was ejected during a volcanic explosion. Lapilli may consist of fresh magma, solid magma from a prior eruption, or basement rocks through which the eruption passed. Accretionary lapilli are pellets formed by the accretion of volcanic ash or dust around moisture droplets; as in hailstones formed of water, these volcanic “hailstones” may show......
  • accretionary prism (oceanic ridge)
    ...which sometimes breaks the ocean surface, as in the case of the Java Trench. Such a ridge is constructed from deformed sediments scraped off the top of the descending oceanic plate and is termed an accretionary prism. A line of explosive volcanoes, extruding (erupting) a lava that forms the volcanic rock andesite, is found on the overriding plate usually 100 kilometres or so from the trench. In...
  • accretionary tectonics (geophysics)
    As subduction leads to contraction of an ocean, elevated regions within the ocean basin such as linear island chains, oceanic ridges, and small crustal fragments (such as Madagascar or Japan), known as terranes, are transported toward the subduction zone, where they are scraped off the descending plate and added—accreted—to the continental margin. Since the Late Devonian and Early......
  • accrued income (economics)
    ...accurate measure of taxpaying ability depends on how income is defined. The only definition that has been found to be completely consistent and free from anomalies and capricious results is “accrued income,” which is the money value of the goods and services consumed by the taxpayer plus or minus any change in net worth during a given period of time. (Tax experts commonly call thi...
  • acculturation (anthropology)
    the processes of change in artifacts, customs, and beliefs that result from the contact of two or more cultures. The term is also used to refer to the results of such changes. Two major types of acculturation, incorporation and directed change, may be distinguished on the basis of the conditions under which cultural contact and change take place....
  • accumulation (glaciation)
    ...and they primarily waste away by melting and runoff or by the breaking off of icebergs (calving). In order for a glacier to remain at a constant size, there must be a balance between income (accumulation) and outgo (ablation). If this mass balance is positive (more gain than loss), the glacier will grow; if it is negative, the glacier will shrink....
  • accumulation (society)
    ...to this theory, the expansion of collective knowledge and capabilities beyond a certain limit is possible only by specialization and differentiation. Growth of technical knowledge stimulates capital accumulation, which leads to rising production levels. Population growth also may be incorporated in this model of cumulative evolution: it is by the accumulation of collective technical knowledge.....
  • accumulation (petroleum trap)
    The porosity (volume of pore spaces) and permeability (capacity for transmitting fluids) of carrier and reservoir beds are important factors in the migration and accumulation of oil. Most petroleum accumulations have been found in clastic reservoirs (sandstones and siltstones). Next in number are the carbonate reservoirs (limestones and dolomites). Accumulations of petroleum also occur in......
  • Accumulation of Capital, The (work by Luxemburg)
    Released from her Warsaw prison, she taught at the Social Democratic Party school in Berlin (1907–14), where she wrote Die Akkumulation des Kapitals (1913; The Accumulation of Capital). In this analysis, she described imperialism as the result of a dynamic capitalism’s expansion into underdeveloped areas of the world. It was during this time also that she began to agita...
  • accumulation, toxic (pathology)
    Toxic accumulation is one of the reasons repetitive exposures of a chemical produce toxicity while a single exposure may not. In a hypothetical case, as depicted in Figure 2, a concentration of more than 100 milligrams per gram in a target tissue is required for chemical A to cause toxic injury. If chemical A is administered at a dose that does not produce toxic levels in the tissue and the......
  • accumulator
    In contrast to primary cells, which are discharged once and then discarded, storage batteries can be supplied with direct current (DC) of the correct polarity and recharged to or near their original energy content and power capability—i.e., they can repeatedly store electrical energy. In discharging, the difference in electrical potential (voltage) of a battery’s electrodes causes......
  • accuracy (measurement)
    Accuracy is the degree of agreement between the experimental result and the true value. Precision is the degree of agreement among a series of measurements of the same quantity; it is a measure of the reproducibility of results rather than their correctness. Errors may be either systematic (determinant) or random (indeterminant). Systematic errors......
  • Accursius, Franciscus (Italian legal scholar)
    Italian legal scholar and leading jurist of the 13th century who was responsible for the renovation of Roman law. He was the last of a series of legal glossators (annotators) of Justinian’s compilation of Roman law....
  • accusative case (grammar)
    ...verbs. It was close typologically to Greek, though the shapes of words were very, even surprisingly, different. The nominal and pronominal declension had seven cases: nominative, genitive, dative, accusative, ablative, instrumental, and locative. However, many of these forms overlapped so that usually only three or four different forms existed; e.g., žam ‘time’...
  • accusatorial procedure (law)
    in law, one of the two methods of exposing evidence in court (the other being the inquisitorial procedure)....
  • accused (law)
    The rules make provision for the joinder of other parties whose participation is considered necessary by the court. Thus, a defendant under English law may issue a notice—called a third-party notice—containing a statement of the nature of the claim made by him against a third party, relevant to the original subject matter of the action or of issues to be determined. A third party......
  • accused, rights of (law)
    in law, the rights and privileges of a person accused of a crime, guaranteeing him a fair trial. These rights were initially (generally from the 18th century on) confined primarily to the actual trial itself, but in the second half of the 20th century many countries began to extend them to the periods before and after the trial....
  • Accused, The (American film)
    Other Nominees...
  • “ACD” (dictionary by Barnhart)
    ...to learn about language. He drew upon his word counts and his “semantic counts” to determine inclusions. The new mode was carried on to the college level by Clarence L. Barnhart in The American College Dictionary (ACD), in 1947. (Barnhart also carried on Thorndike’s work in the Thorndike-Barnhart dictionaries after Thorndike’s death.) After ...
  • ace (playing card)
    In most Western card games, the numeral 1 is designated ace and marked A accordingly. In games based on the superiority of one rank over another, such as most trick-taking games, the ace counts highest, outranking even the king. In games based on numerical value, the ace normally counts 1, as in cribbage, or 11, as an option in blackjack. In games based on arranging cards into ordered series,......
  • ACE (computer science)
    In 1945, the war being over, Turing was recruited to the National Physical Laboratory (NPL) in London to design and develop an electronic computer. His design for the Automatic Computing Engine (ACE) was the first relatively complete specification of an electronic stored-program general-purpose digital computer. Had Turing’s ACE been built as planned, it would have had considerably more mem...
  • ACE (enzyme)
    ...the bloodstream by the kidney when the blood pressure falls. It acts on a plasma protein to produce a peptide, angiotensin I, which consists of a chain of 10 amino acids. This in turn is acted on by angiotensin converting enzyme (ACE) to produce an eight-amino-acid peptide, angiotensin II (a potent vasoconstrictor), which raises the blood pressure. ACE inhibitors, which block the formation of.....
  • ace (sports)
    Any shot beyond an opponent’s reach is called a placement. The most effective placement is a kill, in which the ball rebounds at a height so low that it is impossible to return it. An ace is a legal serve that eludes the receiver. The greater variety of angle shots—for example, sidewall to front wall, ceiling to front, side to back—makes the four-wall game the most demanding f...
  • Ace, Goodman (American writer)
    American radio writer and performer and producer-writer for television, whose literate writing, wry humour, and relaxed style influenced numerous radio and television writers from the 1930s on....
  • ACE inhibitor (drug)
    ...activation of AT1 receptors. Thus, it was assumed that drugs that inhibit ACE would lower blood pressure. This assumption turned out to be correct, and a class of antihypertensive drugs called ACE inhibitors was developed. Similarly, once the role of AT1 receptors in blood pressure maintenance was understood, it was assumed that drugs that could block AT1 receptors would produce......
  • Aceh (province, Indonesia)
    semiautonomous province of Indonesia, forming the northern extremity of the island of Sumatra. Aceh is surrounded by water on three sides: the Indian Ocean to the west and north and the Strait of Malacca to the east. Its boundary with Sumatera Utara (North Sumatra) province to the southeast extends north-south from Salahaji on the northeaste...
  • Acehnese (people)
    one of the main ethnic groups on the island of Sumatra, Indonesia. They were estimated to number roughly 2,100,000 in the late 20th century. They speak a language of the Austronesian (Malayo-Polynesian) family....
  • Acehnese language
    ...languages include Cebuano, Tagalog, Ilokano, Hiligaynon, Bikol, Waray, Kapampangan, and Pangasinan of the Philippines; Malay, Javanese, Sundanese, Madurese, Minangkabau, the Batak languages, Acehnese, Balinese, and Buginese of western Indonesia; and Malagasy of Madagascar. Each of these languages has more than one million speakers. Javanese alone accounts for about one-quarter of all......
  • Acehnese War (Southeast Asian history)
    (1873–1904), an armed conflict between The Netherlands and the Muslim sultanate of Acheh (now Aceh) in northern Sumatra that resulted in Dutch conquest of the Acehnese and, ultimately, in Dutch domination of the entire region. In 1871 The Netherlands and Britain had signed a treaty that recognized Dutch influence in northern Sumatra in return for Dutch ...
  • Acemhöyük (ancient city, Turkey)
    The destruction of Nesa and its merchant colony marked the end of Assyrian trade not only there but also in other merchant colonies, such as Acemhöyük (probably the ancient Purushkhanda) and Hattusas (site of the later Hittite capital), which, together with a number of other cities in central Anatolia, were also violently destroyed. It is not clear who was responsible for the......
  • Acentropus (insect genus)
    ...number of moth families the females are wingless, although the males are fully winged (bagworm moths [family Psychidae], some tussock moths [family Lymantriidae]). In the aquatic snout moth (Acentropus) some females are wingless, while some females and males are winged. There are eight main wing veins, each with a characteristic pattern. These are usually designated according to....
  • Acephala (class of mollusks)
    any of more than 15,000 species of clams, oysters, mussels, scallops, and other members of the phylum Mollusca characterized by a shell that is divided from front to back into left and right valves. The valves are connected to one another at a hinge. Primitive bivalves ingest sediment; however, in most s...
  • acephalous line (literature)
    in prosody, a line of verse that is lacking the normal first syllable. An iambic line with only one syllable in the first foot is a headless line, as in the third line of the following stanza of A.E. Housman’s poem “To an Athlete Dying Young”:The time you won your town the raceWe chaired you through the market-place;Ma...
  • Acer (plant)
    (Acer), any of a large genus (about 200 species) of shrubs or trees in the family Sapindaceae, widely distributed in the North Temperate Zone but concentrated in China. Maples constitute one of the most important groups of ornamentals for planting in lawns, along streets, and in parks. They offer a great variety of form, size, and foliage; many display striking autumn colour. Several yield ...
  • Acer campestre (plant)
    Among the popular smaller maples the hedge, or field, maple (A. campestre) and Amur, or ginnala, maple (A. ginnala) are useful in screens or hedges; both have spectacular foliage in fall, the former yellow and the latter pink to scarlet. The Japanese maple (A. palmatum), developed over centuries of breeding, provides numerous attractive cultivated varieties with......
  • Acer capillipes (plant)
    In one group of maples, the vertically striped silvery-white young bark provides an attractive winter landscaping feature. These trees are the striped maple (A. pennsylvanicum), the red snake-bark maple (A. capillipes), the Her’s maple (A. hersii), and the David’s maple (A. davidii). The chalk maple, with whitish bark, is sometimes classified as A. leuc...
  • Acer cappadocicum (plant)
    ...tall, include the big-toothed maple (A. grandidentatum); some believe it to be a subspecies of sugar maple, a Rocky Mountain tree, often multistemmed, displaying pink to red fall foliage. Coliseum maple (A. cappadocicum) and Miyabe maple (A. miyabei) provide golden-yellow fall colour. The three-flowered maple (A. triflorum) and the paperbark maple (A.......
  • Acer circinatum (plant)
    ...Japanese maple (A. palmatum), developed over centuries of breeding, provides numerous attractive cultivated varieties with varying leaf shapes and colours, many useful in small gardens. The vine maple (A. circinatum), of wide-spreading, shrubby habit, has purple and white spring flowers and brilliant fall foliage. The shrubby Siebold maple (A. sieboldianum) has seven- to......
  • Acer davidii (plant)
    ...an attractive winter landscaping feature. These trees are the striped maple (A. pennsylvanicum), the red snake-bark maple (A. capillipes), the Her’s maple (A. hersii), and the David’s maple (A. davidii). The chalk maple, with whitish bark, is sometimes classified as A. leucoderme, although some authorities consider it a subspecies of sugar maple....
  • Acer ginnala (plant)
    Among the popular smaller maples the hedge, or field, maple (A. campestre) and Amur, or ginnala, maple (A. ginnala) are useful in screens or hedges; both have spectacular foliage in fall, the former yellow and the latter pink to scarlet. The Japanese maple (A. palmatum), developed over centuries of breeding, provides numerous attractive cultivated varieties with varying......
  • Acer grandidentatum (plant)
    Medium-sized maples, often more than 9 metres (30 feet) tall, include the big-toothed maple (A. grandidentatum); some believe it to be a subspecies of sugar maple, a Rocky Mountain tree, often multistemmed, displaying pink to red fall foliage. Coliseum maple (A. cappadocicum) and Miyabe maple (A. miyabei) provide golden-yellow fall colour. The......
  • Acer griseum (plant)
    ...pink to red fall foliage. Coliseum maple (A. cappadocicum) and Miyabe maple (A. miyabei) provide golden-yellow fall colour. The three-flowered maple (A. triflorum) and the paperbark maple (A. griseum) have tripartite leaves and attractive peeling bark, in the former tannish and in the latter copper brown....
  • Acer hersii (tree)
    ...striped silvery-white young bark provides an attractive winter landscaping feature. These trees are the striped maple (A. pennsylvanicum), the red snake-bark maple (A. capillipes), the Her’s maple (A. hersii), and the David’s maple (A. davidii). The chalk maple, with whitish bark, is sometimes classified as A. leucoderme, although some authoritie...
  • Acer leucoderme (plant)
    ...These trees are the striped maple (A. pennsylvanicum), the red snake-bark maple (A. capillipes), the Her’s maple (A. hersii), and the David’s maple (A. davidii). The chalk maple, with whitish bark, is sometimes classified as A. leucoderme, although some authorities consider it a subspecies of sugar maple....
  • Acer macrophyllum (plant)
    Large maples, usually in excess of 30 metres high, that are much planted for shade include the sugar (A. saccharum), silver (A. saccharinum), and red (A. rubrum) maples. The Oregon, or bigleaf, maple (A. macrophyllum) provides commercially valuable wood darker than that of other maples; it shows bright-orange fall foliage. The Sycamore maple (A.......
  • Acer miyabei (plant)
    ...grandidentatum); some believe it to be a subspecies of sugar maple, a Rocky Mountain tree, often multistemmed, displaying pink to red fall foliage. Coliseum maple (A. cappadocicum) and Miyabe maple (A. miyabei) provide golden-yellow fall colour. The three-flowered maple (A. triflorum) and the paperbark maple (A. griseum) have tripartite leaves and attractive.....
  • Acer negundo (plant)
    (Acer negundo), hardy and fast-growing tree, of the soapberry family (Sapindaceae), native to the central and eastern United States. Introduced to Europe, it is widely cultivated there as an ornamental. The tree grows to 9–15 m (30–50 feet) tall. The compound leaves (rare among maples) consist of three, five, or seven coarsely toothed leaflets. The single seed is borne in a ...
  • Acer palmatum (plant)
    ...(A. campestre) and Amur, or ginnala, maple (A. ginnala) are useful in screens or hedges; both have spectacular foliage in fall, the former yellow and the latter pink to scarlet. The Japanese maple (A. palmatum), developed over centuries of breeding, provides numerous attractive cultivated varieties with varying leaf shapes and colours, many useful in small gardens. The......
  • Acer pennsylvanicum (plant)
    In one group of maples, the vertically striped silvery-white young bark provides an attractive winter landscaping feature. These trees are the striped maple (A. pennsylvanicum), the red snake-bark maple (A. capillipes), the Her’s maple (A. hersii), and the David’s maple (A. davidii). The chalk maple, with whitish bark, is sometimes classified as A.......
  • Acer platanoides (plant)
    The ash-leaved maple, or box elder, is a fast-growing tree of limited landscape use. The Norway maple (A. platanoides), a handsome, dense, round-headed tree, has spectacular greenish-yellow flower clusters in early spring; many cultivated varieties are available with unusual leaf colour (red, maroon, bronze, or purple) and growth form (columnar, globular, or pyramidal)....
  • Acer pseudoplatanus (plant)
    ...red (A. rubrum) maples. The Oregon, or bigleaf, maple (A. macrophyllum) provides commercially valuable wood darker than that of other maples; it shows bright-orange fall foliage. The Sycamore maple (A. pseudoplatanus), an important shade and timber tree in Europe, has many ornamental varieties....
  • Acer rubrum (plant)
    (Acer rubrum), large, irregularly narrow tree of the soapberry family (Sapindaceae), cultivated for its shade and spectacular autumn colour. It is one of the most common trees in its native eastern North America....
  • Acer saccharinum (plant)
    (Acer saccharinum), large, spreading tree, of the soapberry family (Sapindaceae), popular as a rapid-growing shade tree. Native to eastern North America, it is widely cultivated elsewhere....
  • Acer saccharum (plant)
    (Acer saccharum) large tree in the soapberry family (Sapindaceae), native to eastern North America and widely grown as an ornamental and shade tree. It is a commercially important source of maple syrup, maple sugar, and hardwood lumber useful in furniture manufacture and flooring. Some trees develop special grain patterns such as bird’s-eye maple (with dots suggest...
  • Acer sieboldianum (plant)
    ...shapes and colours, many useful in small gardens. The vine maple (A. circinatum), of wide-spreading, shrubby habit, has purple and white spring flowers and brilliant fall foliage. The shrubby Siebold maple (A. sieboldianum) has seven- to nine-lobed leaves that turn red in fall....
  • Acer triflorum (plant)
    ...a Rocky Mountain tree, often multistemmed, displaying pink to red fall foliage. Coliseum maple (A. cappadocicum) and Miyabe maple (A. miyabei) provide golden-yellow fall colour. The three-flowered maple (A. triflorum) and the paperbark maple (A. griseum) have tripartite leaves and attractive peeling bark, in the former tannish and in the latter copper brown....
  • Aceraceae (plant family)
    Included within Sapindaceae are the genera from two former families, Aceraceae and Hippocastanaceae. The most important genus in Aceraceae was Acer (maple), with about 110 species, which is found across the north temperate zone from western North America to Japan. Maple trees form an important component of the deciduous forests of North America, Europe, and Asia. The distribution of the......
  • Aceras anthropophorum (plant)
    (species Aceras anthropophorum), the only species in the genus Aceras, plant family Orchidaceae. It is native to grasslands of Great Britain, Eurasia, and northern Africa. The man orchid derives its name from the helmeted, humanlike shape of its flowers....
  • Acerbo Law (Italian history)
    ...in 1933, he abandoned his military uniform for a civilian suit and bowed profusely to President Paul von Hindenburg in public ceremonies. In 1923 Mussolini proposed an electoral reform, known as the Acerbo Law, that gave two-thirds of the seats in Parliament to the party that received the largest number of votes. Although Mussolini insisted that he wanted to save Parliament rather than undermin...
  • Acerentomidae (insect family)
    ...ProtentomidaeAbdominal appendages 2-segmented with up to 4 setae, 2 pairs with terminal vesicles.Family AcerentomidaeAbdominal appendages 2-segmented with up to 4 setae, anterior pair with terminal......
  • Acerentomoidea (proturan suborder)
    ...EosentomidaePairs of abdominal appendages alike, 2-segmented with 5 setae.Suborder AcerentomoideaTracheal system absent; claw of middle and hindlegs broadly boat-shaped; lids to gland openings large and with or without teeth on posterior......
  • Acernus (Polish poet)
    Polish poet whose work in Latin and Polish is valuable chiefly as cultural history....
  • acerola (plant)
    common name for various tropical and subtropical trees and shrubs of the genera Bunchiosa and Malpighia (family Malpighiaceae), especially M. glabra, M. punicifolia, and M. urens....
  • acervuli (biology)
    an open, saucer-shaped asexual fruiting body found in fungi (kingdom Fungi). Always developed below the epidermis of the host tissue, it bears conidiophores (specialized filaments, or hyphae) that form conidia (spores)....
  • acervulus (biology)
    an open, saucer-shaped asexual fruiting body found in fungi (kingdom Fungi). Always developed below the epidermis of the host tissue, it bears conidiophores (specialized filaments, or hyphae) that form conidia (spores)....
  • Acestes (Greek mythology)
    in Greek mythology, legendary king of Segesta (Greek Egesta) in Sicily. His mother, Egesta, had been sent from Troy by her parents to save her from being devoured by a sea serpent. Going to Sicily she met the river god Crimisus, by whom she became the mother of Acestes....
  • acesulfame potassium (chemistry)
    Acesulfame potassium (marketed as Sunette) was approved in the United States in 1988. It is about 130–200 times as sweet as sucrose, has good shelf life and high stability, and was initially used in dry food mixes....
  • acetabulae (cymbal)
    ...closely those used by the Greeks and the Romans. Probably cast rather than spun, they were held horizontally, one above the other. Small cup-shaped cymbals called acetabulae, made of brass or silver, are mentioned by Cassiodorus (d. c. 580) and Isidore of Sevilla. Although the modern practice of striking a single cymbal with a stick was......
  • Acetabularia (alga genus)
    genus of one-celled, umbrella-like green algae found in subtropical seas, called the “mermaid’s wine glass.” At the top of the tall, slender stalk, 0.5 to 10 cm (0.2 to 3.9 inches) long, is a ring of branches that may be separate or fused to form a cap. Near the base of its stalk, Acetabularia has a large nucleus that divides many times when the alga matures and reprod...
  • acetabulum (physiology)
    The pelvic girdle consists originally of three bones, which become fused in early adulthood and each of which contributes a part of the acetabulum, the deep cavity into which the head of the thighbone, or femur, is fitted. The flaring upper part of the girdle is the ilium; the lower anterior part, meeting with its fellow at the midline, is the pubis; and the lower posterior part is the ischium.......
  • acetal resin (chemical compound)
    Also called polyoxymethylene (POM) or simply acetal, polyacetal has the simplest structure of all the polyethers. It is manufactured in a solution process by anionic or cationic chain-growth polymerization of formaldehyde (H2C=O), a reaction analogous to vinyl polymerization. By itself, the polymer is unstable and reverts to monomer on heating to 120° C (250°......
  • acetaldehyde (chemical compound)
    an aldehyde used as a starting material in the synthesis of 1-butanol (n-butyl alcohol), ethyl acetate, perfumes, flavourings, aniline dyes, plastics, synthetic rubber, and other chemical compounds. It has been manufactured by the hydration ...
  • acetaldol (chemical compound)
    Another important reaction of a carbon nucleophile with an aldehyde is the aldol reaction (also called aldol condensation), which takes place when any aldehyde possessing at least one α-hydrogen is treated with sodium hydroxide or sometimes with another base. The product of an aldol reaction is a β-hydroxyaldehyde....
  • acetaminophen (chemical compound)
    drug used in the treatment of mild pain, such as headache and pain in joints and muscles, and to reduce fever. It is formed in the body as a metabolite of acetanilid or phenacetin, which were once commonly used drugs, and is responsible for their analgesic effects. Acetaminophen reliev...
  • acetanilide (drug)
    synthetic organic compound introduced in therapy in 1886 as a fever-reducing drug. Its effectiveness in relieving pain was discovered soon thereafter, and it was used as an alternative to aspirin for many years in treating such common complaints as headache, menstrual cramps, and rheumatism. Excessive or prolonged use engenders toxic side effects: it interferes with the function of hemoglobin, th...
  • acetate (textile fibre)
    The full exploitation on a commercial scale of the acetone-soluble material was accomplished by two Swiss brothers, Henri and Camille Dreyfus, who during World War I built a factory in England for the production of cellulose diacetate to be used as a nonflammable “dope” for coating fabric airplane wings. After the war, with no further......
  • acetate (ester)
    ...molecule is converted by this action to acetaldehyde, itself a highly toxic substance, but the acetaldehyde is immediately acted upon by another enzyme, aldehyde dehydrogenase, and converted to acetate, most of which enters the bloodstream and is ultimately oxidized to carbon dioxide and water. Considerable utilizable energy—200 calories per ounce of alcohol (about 7.1 calories per......
  • acetate dye (dye)
    ...chains bearing polar groups, mainly nitriles, made by copolymerization of acrylonitrile (at least 85 percent) with small amounts (10–15 percent) of components such as acrylamide and vinyl acetate to produce a fibre with improved dyeability. Fibres with 35–85 percent acrylonitrile are termed modacrylics....
  • acetate fibre (textile fibre)
    The full exploitation on a commercial scale of the acetone-soluble material was accomplished by two Swiss brothers, Henri and Camille Dreyfus, who during World War I built a factory in England for the production of cellulose diacetate to be used as a nonflammable “dope” for coating fabric airplane wings. After the war, with no further......
  • acetate flagellate (protozoan)
    ...coloured flagellates combine autotrophy with heterotrophy and are, strictly speaking, mixotrophs. Some members of the Euglenida, Cryptomonadida, and Volvocida, for example, are commonly called the acetate flagellates because their preferred food sources are acetates, simple fatty acids, and alcohols. In the presence of the correct nutrients, these flagellates are able to switch from......
  • acetate rayon (textile fibre)
    The full exploitation on a commercial scale of the acetone-soluble material was accomplished by two Swiss brothers, Henri and Camille Dreyfus, who during World War I built a factory in England for the production of cellulose diacetate to be used as a nonflammable “dope” for coating fabric airplane wings. After the war, with no further......
  • acetazolamide (drug)
    ...Inhibition of carbonic anhydrase produces diuresis (urine formation). Subsequently, many sulfanilamide-like compounds were synthesized and screened for their ability to inhibit carbonic anhydrase. Acetazolamide, which was developed by scientists at Lederle Laboratories (now a part of Wyeth Pharmaceuticals, Inc.), became the first of a class of diuretics that serve as carbonic anhydrase......
  • acetic acid (chemical compound)
    the most important of the carboxylic acids. A dilute (approximately 5 percent by volume) solution of acetic acid produced by fermentation and oxidation of natural carbohydrates is called vinegar; a salt, ester, or acylal of acetic acid is called acetate. Industrially, acetic acid is u...
  • acetic anhydride (chemical compound)
    ...combines with compounds containing an easily replaced hydrogen atom to yield derivatives of acetic acid. The only important industrial use of ketene itself is its reaction with acetic acid to form acetic anhydride....
  • acetoacetic acid (chemical compound)
    Pyruvic acid and acetoacetic acid are the simplest and most important of the α-keto and β-keto acids, respectively....
  • acetoacetic ester (chemical compound)
    an ester widely used as an intermediate in the synthesis of many varieties of organic chemical compounds. Industrially it is employed in the manufacture of synthetic drugs and dyes....
  • acetoacetic ester synthesis
    Acetoacetic acid (in the form of its ethyl ester, called ethyl acetoacetate) is the starting compound in a series of reactions (the acetoacetic ester synthesis) that is parallel to the malonic ester synthesis....
  • acetoacetyl-S-ACP (chemical compound)
    ...malonyl moiety (-OOCH2CO−). Simultaneously, the carbon dioxide fixed in step [62] is lost, leaving as a product a four-carbon moiety attached to ACP and called acetoacetyl-S-ACP [64]....
  • Acetobacter (bacteria)
    In 1864 the French physicist Louis Pasteur showed that it is Acetobacter bacteria that cause the conversion of alcohol to acetic acid. These bacteria work together symbiotically, producing enough acetic acid to prevent invasion by other organisms....
  • Acetobacterium woodii (bacteria)
    ...and Desulfuromonas reduce sulfate and elemental sulfur (S), respectively, yielding sulfide (S2−), and the bacterium Acetobacterium woodii and methanogenic archaea, such as Methanobacterium thermautotrophicum, reduce carbon dioxide to acetate and methane, respectively. The......
  • acetomeroctol (antiseptic)
    ...and Desulfuromonas reduce sulfate and elemental sulfur (S), respectively, yielding sulfide (S2−), and the bacterium Acetobacterium woodii and methanogenic archaea, such as Methanobacterium thermautotrophicum, reduce carbon dioxide to acetate and methane, respectively. The.........
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