Altis, in Greek religion, the sacred grove of Zeus, or the sacred precinct in Olympia, Greece. It was an irregular quadrangular area more than 200 yards (183 m) on each side, and walled except to the north, where it was bounded by the Kronion (hill of Cronus). In it were the temples of Zeus and of

global warming: Climatic variation since the last glaciation: …sometimes referred to as the Mid-Holocene Climatic Optimum. The relative warmth of average near-surface air temperatures at this time, however, is somewhat unclear. Changes in the pattern of insolation favoured warmer summers at higher latitudes in the Northern Hemisphere, but these changes also produced cooler winters in the Northern Hemisphere…

climate: Variation with height: There are two main levels where the atmosphere is heated—namely, at Earth’s surface and at the top of the ozone layer (about 50 km, or 30 miles, up) in the stratosphere. Radiation balance shows a net gain at these levels in most cases. Prevailing…

barometer: …terms of atmospheric pressure or altitude above sea level. The concept of altitude above sea level, based on barometric pressure, is used to create one type of aircraft altimeter.

altitude and azimuth, in astronomy, gunnery, navigation, and other fields, two coordinates describing the position of an object above Earth. Altitude in this sense is expressed as angular elevation (up to 90°) above the horizon. Azimuth is the number of degrees clockwise from due north (usually) to

altitude sickness, acute reaction to a change from sea level or other low-altitude environments to altitudes above 8,000 feet (2,400 metres). Altitude sickness was recognized as early as the 16th century. In 1878 French physiologist Paul Bert demonstrated that the symptoms of altitude sickness are

map: Symbolization: Hypsographic tinting is relatively easy, particularly since photomechanical etching and other steps can be used to provide negatives for the respective elevation layers. Difficulty in the reproduction process is sometimes a deterrent to the use of treatments involving the manipulation of contours.

telescope: Reflecting telescopes: …Canary Islands, Spain, has an altitude-azimuth mounting. The significance of the latter design is that the telescope must be moved both in altitude and in azimuth as it tracks a celestial object. Equatorial mountings, by contrast, require motion in only one coordinate while tracking, since the declination coordinate is constant.…

Thomas J.J. Altizer was an American radical theologian associated with the Death of God movement in the 1960s and ’70s. A graduate of the University of Chicago (A.B. 1948, A.M. 1951, Ph.D. 1955), Altizer taught religion first at Wabash College (Crawfordsville, Indiana) from 1954 to 1956 and then at

Thomas J.J. Altizer was an American radical theologian associated with the Death of God movement in the 1960s and ’70s. A graduate of the University of Chicago (A.B. 1948, A.M. 1951, Ph.D. 1955), Altizer taught religion first at Wabash College (Crawfordsville, Indiana) from 1954 to 1956 and then at

the Dreaming, mythological period of time that had a beginning but no foreseeable end, during which the natural environment was shaped and humanized by the actions of mythic beings. Many of these beings took the form of human beings or of animals (“totemic”); some changed their forms. They were

the Dreaming, mythological period of time that had a beginning but no foreseeable end, during which the natural environment was shaped and humanized by the actions of mythic beings. Many of these beings took the form of human beings or of animals (“totemic”); some changed their forms. They were

Benjamin Altman was an American merchant, art collector, and philanthropist who established one of the world’s great department stores, B. Altman & Co. Altman had little formal schooling, but at the age of 25 he opened his first dry-goods store in Manhattan and in 1906 moved it to the uptown

Klaus Barbie was a Nazi leader, head of the Gestapo in Lyon from 1942 to 1944, who was held responsible for the death of some 4,000 persons and the deportation of some 7,500 others. Barbie was a member of the Hitler Youth and in 1935 joined the Sicherheitsdienst (SD; “Security Service”), a special

Robert Altman was an unconventional and independent American motion-picture director, whose works emphasize character and atmosphere over plot in exploring themes of innocence, corruption, and survival. Perhaps his best-known film was his first and biggest commercial success, the antiwar comedy

Sam Altman is an American entrepreneur who was president of the start-up accelerator Y Combinator from 2014 to 2019 and chief executive officer (CEO) of the artificial intelligence (AI) company OpenAI beginning in 2019. He has been compared to tech visionaries, including Steve Jobs and Bill Gates,

Sam Altman is an American entrepreneur who was president of the start-up accelerator Y Combinator from 2014 to 2019 and chief executive officer (CEO) of the artificial intelligence (AI) company OpenAI beginning in 2019. He has been compared to tech visionaries, including Steve Jobs and Bill Gates,

Sidney Altman was a Canadian American molecular biologist who, with Thomas R. Cech, received the 1989 Nobel Prize for Chemistry for their discoveries concerning the catalytic properties of RNA, or ribonucleic acid. Altman received a B.S. in physics in 1960 from the Massachusetts Institute of

Estonia: Swedish period: By the Truce of Altmark (1629), which ended the first Polish-Swedish war, the Polish-Lithuanian Commonwealth surrendered to Sweden the major part of Livonia, so that all Estonian lands then came under Swedish rule.

Germany: Drainage of Germany: Further exceptions are the Altmühl and the Naab, which follow a southerly direction until becoming north-bank tributaries of the Danube, and the Havel, which flows south, west, and north before emptying into the Elbe River. River flow relates mainly to climate, albeit not in a simple way; for example,…

alto, (Italian: “high”), in vocal music the register approximately between the F below middle C to the second D above—the second highest part in four-part music. The word alto originally referred to the highest male voice, singing falsetto (see countertenor). Alto derives from the term contratenor

Charles P. Thacker: …the project that developed the Alto, the first personal computer, in 1973. Alto used a bitmap display in which everything on the computer screen was, in effect, a picture and had a graphical user interface in which programs were shown in windows that could be manipulated by using a mouse.…

Austria: Restoration of sovereignty: …part of the Italian Trentino–Alto Adige region) and the problem of association with the European Economic Community (EEC; later succeeded by the European Union). During the Paris Peace Conference of 1946, an agreement had been signed guaranteeing the rights of the German-speaking population of Südtirol, a region that Italy…

Portugal: South: …and the Guadiana, the Alto Alentejo is a continuation of the Spanish tablelands—a series of plateaus, either crystalline (Paleozoic Cambrian and Silurian schists), at 600 to 1,300 feet (180 to 400 metres) with poor soils except where outcrops of diorite have weathered into rich black soils, or limestone, with piedmont…

tenor horn, brass wind instrument derived from the cornet and the valved bugle, or flügelhorn. A saxhorn of tenor range and a tenor bugle are also sometimes called tenor horns. The tenor horn was used in Prussian cavalry bands by 1829. It has three valves, a cup mouthpiece, and a narrow bore and

English horn, orchestral woodwind instrument, a large oboe pitched a fifth below the ordinary oboe, with a bulbous bell and, at the top end, a bent metal crook on which the double reed is placed. It is pitched in F, being written a fifth higher than it sounds. Its compass is from the E below middle

South America: Geologic history: …(with the exception of the Alto Paraguay craton) those now appear as upwarped massifs arrayed from north to south in the immense eastern portion of the continent; a number of other Precambrian crustal blocks also were accreted along the margins of South America over geologic time. The lofty ranges and…

Itaipú Dam: …hollow gravity dam on the Alto (Upper) Paraná River at the Brazil-Paraguay border. It is located north of the town of Ciudad del Este, Paraguay.

Pelotas River, river in southern Brazil, rising on the western slope of the Serra Geral at Alto do Bispo in Santa Catarina estado (state), on the Atlantic coast. It arches northwestward across the uplands for approximately 280 miles (450 km) before receiving the Canoas River and becoming the

contralto, in vocal music, the second-highest voice in four-part music, also called alto

countertenor, in music, adult male alto voice, either natural or falsetto. In England the word generally refers to a falsetto alto rather than a high tenor. Some writers reserve the term countertenor for a naturally produced voice, terming the falsetto voice a male alto. Derived from the

Apennine Range: Physiography: …Calabrian Apennines, 6,414 feet at Mount Alto; and, finally, the Sicilian Range, 10,902 feet at Mount Etna. The ranges in Puglia (the “boot heel” of the peninsula) and southeastern Sicily are formed by low, horizontal limestone plateaus, which remained less affected by the Alpine orogeny.

relief: In a high relief, or alto-relievo, the forms project at least half or more of their natural circumference from the background and may in parts be completely disengaged from the ground, thus approximating sculpture in the round. Middle relief, or mezzo-relievo, falls roughly between the high and…

cloud: …(23,000 to 6,500 feet), are altocumulus and altostratus. Low clouds, 2 to 0 km (6,500 to 0 feet), are stratocumulus, stratus, and nimbostratus. A cloud that extends through all three heights is called a cumulonimbus. A cloud at the surface is called a fog.

Alton, town (parish), East Hampshire district, administrative and historic county of Hampshire, southern England. It lies among the downs on the River Wey, about 18 miles (29 km) northeast of Winchester by road. The Church of St. Lawrence is in the Perpendicular style with a Norman tower. Eggar’s

Alton, city, Madison county, southwestern Illinois, U.S. Part of the St. Louis, Missouri, metropolitan area, Alton lies on the Mississippi River (bridged) near its confluence with the Missouri River. The city was named for a son of Colonel Rufus Easton, a St. Louis land speculator who laid out the

Charles Kingsley: His second, the much superior Alton Locke (1850), is the story of a tailor-poet who rebels against the ignominy of sweated labour and becomes a leader of the Chartist movement. Kingsley advocated adult education, improved sanitation, and the growth of the cooperative movement, rather than political change, for the amelioration…

Charles Talbot, duke and 12th earl of Shrewsbury was an English statesman who played a leading part in the Glorious Revolution (1688–89) and who was largely responsible for the peaceful succession of the Hanoverian George I to the English throne in 1714. Although he displayed great determination in

Altona, northwest district of the city and Land (state) of Hamburg, northwestern Germany. It lies on cliffs above the right bank of the Elbe River. The name may have come originally from allzu-nah (“all too near”), which was the Hamburgers’ designation for an inn that lay too close to their

photoengraving: Basis for selection of screen ruling: …glass screens was the “Altone Gradar Screen,” manufactured in Germany. These are glass screens, ruled and etched in the usual manner, but with the rulings of the two glass elements filled with a transparent magenta lacquer of two different optical densities. When the screens are assembled, lines in one…

Altoona, city, Blair county, central Pennsylvania, U.S. It is situated on the eastern slopes of the Allegheny Front, a segment of the Allegheny Mountains that separates the Atlantic from the Mississippi valley watersheds. The city lies 45 miles (72 km) by road northeast of Johnstown. It was founded

atmosphere: Cloud formation within the troposphere: …stratiform clouds are known as altostratus. In the upper troposphere, the terms cirrostratus and cirrus are used. The cirrus cloud type refers to thin, often wispy, cirrostratus clouds. Stratiform clouds that both extend through a large fraction of the troposphere and precipitate are called nimbostratus.

Benvenuto Cellini: Later years: …and patron of the arts, Bindo Altoviti (c. 1550; Isabella Stewart Gardner Museum, Boston), was also executed by Cellini in Florence. After the unveiling of the Perseus (1554), he began work on a marble crucifix originally destined for his own tomb in the Florentine church of SS. Annunziata; this is…

treaties of Altranstädt, agreements made during the Second, or Great, Northern War (1700–21) by the Swedish king Charles XII with Augustus II, king of Poland and elector of Saxony (Sept. 24, 1706), and with the Holy Roman emperor Joseph I (Sept. 1, 1707). Shortly after Augustus was crowned king of

Altria Group, American holding company founded in 1985, the owner of several major American companies with interests in tobacco products and wine, most notably Philip Morris Inc., the largest cigarette manufacturer in the United States. Its headquarters are in Richmond, Virginia. The ancestor of

mammal: Estrus and other cycles: …dependent upon the parent (altricial). They reach sexual maturity in about one year.

altruism, in ethics, a theory of conduct that regards the good of others as the end of moral action. The term (French altruisme, derived from Latin alter, “other”) was coined in the 19th century by Auguste Comte, the founder of Positivism, and adopted generally as a convenient antithesis to egoism.

animal behaviour: Function: …however, animals engage in apparent altruism (that is, they exhibit behaviour that increases the fitness of other individuals by engaging in activities that decrease their own reproductive success). For example, American zoologist Paul Sherman found that female Belding’s ground squirrels (Spermophilus beldingi) give staccato whistles that warn nearby conspecifics of…

animal behaviour: Function: …however, animals engage in apparent altruism (that is, they exhibit behaviour that increases the fitness of other individuals by engaging in activities that decrease their own reproductive success). For example, American zoologist Paul Sherman found that female Belding’s ground squirrels (Spermophilus beldingi) give staccato whistles that warn nearby conspecifics of…

Bremen: Geography: Other outstanding features in the Altstadt, or Old Town, in the restored heart of the city, are the famous marketplace with its 11th-century cathedral, a picturesque row of old gabled houses, and the modern-style Parliament. Districts heavily bombed in World War II (69 percent of the houses were destroyed) were…

Hamburg: The city layout: …of the city is the Altstadt (Old Town), the former medieval settlement, bounded by the harbour and by a string of roads that follow the line of the old fortifications. Within this core there are few great buildings to remind the visitor of the city’s thousand-year history apart from the…

Altun Mountains, mountain range in the southern part of the Uygur Autonomous Region of Xinjiang, northwestern China. Branching off from the Kunlun Mountains, the range runs for more than 400 miles (650 km) from southwest to northeast to form the boundary between the Tarim Basin to the north and the

The Heights of Macchu Picchu, poem by Pablo Neruda, published in 1947 as Alturas de Macchu Picchu and later included as part of his epic Canto general. It is considered one of Neruda’s greatest poetic works. The 12 sections of The Heights of Macchu Picchu represent separate phases of a journey,

Altus, city, seat (1907) of Jackson county, southwestern Oklahoma, U.S. The original settlement of Frazier (1886), near Bitter Creek (Salt Fork of the Red River) on the Great Western cattle trail, was subject to flooding; it was renamed Altus (Latin: “high”) in 1891, after it was moved to the

Altus: Altus Reservoir, the project’s chief unit, impounded on the North Fork of the Red River by Lugert Dam, lies within Quartz Mountain State Park, 18 miles (29 km) north. Oil fields lie to the northwest. The city is the site of Western Oklahoma State College…

Jeseník Mountains, mountain range that forms the eastern section of the Sudeten mountain system in the northern Czech Republic. The range lies in northern Moravia, bordering the Polish frontier. The Hrubý (High) Jeseník, also known as Vysoký Jeseník, reaches the highest point at Praděd (4,892 feet

Altona, northwest district of the city and Land (state) of Hamburg, northwestern Germany. It lies on cliffs above the right bank of the Elbe River. The name may have come originally from allzu-nah (“all too near”), which was the Hamburgers’ designation for an inn that lay too close to their

Altun Mountains, mountain range in the southern part of the Uygur Autonomous Region of Xinjiang, northwestern China. Branching off from the Kunlun Mountains, the range runs for more than 400 miles (650 km) from southwest to northeast to form the boundary between the Tarim Basin to the north and the

Shortland Islands: …largest islands are Shortland (or Alu), which has an area of 10 by 8 miles (16 by 13 km) and rises to 607 feet (185 metres); and Fauro Island, which measures 10 by 6 miles (16 by 10 km) and rises to 1,312 feet (400 metres) at two points along…

computer science: Architecture and organization: …of a control unit, an arithmetic logic unit (ALU), a memory unit, and input/output (I/O) controllers. The ALU performs simple addition, subtraction, multiplication, division, and logic operations, such as OR and AND. The memory stores the program’s instructions and data. The control unit fetches data and instructions from memory and…

lepidopteran: Annotated classification: Family Alucitidae (many-plumed moths) 130 species worldwide; each wing is very deeply cleft into 6 or more narrow plumelike divisions. Superfamily Nepticuloidea Approximately 900 species worldwide; females with one genital opening and a soft ovipositor. Family Nepticulidae (

lepidopteran: Annotated classification: Superfamily Alucitoidea Almost 150 species worldwide; this superfamily and the related Pterophoroidea are the only families with deeply lobed wings. Family Alucitidae (many-plumed moths) 130 species worldwide; each wing is very deeply cleft into 6 or more narrow plumelike divisions. Superfamily

T.M. Aluko was a Nigerian writer whose short stories and novels deal with social change and the clash of cultures in modern Africa. A civil engineer and town planner by profession, Aluko was educated in Ibadan, Lagos, and London and held positions as director of public works for western Nigeria and

T.M. Aluko was a Nigerian writer whose short stories and novels deal with social change and the clash of cultures in modern Africa. A civil engineer and town planner by profession, Aluko was educated in Ibadan, Lagos, and London and held positions as director of public works for western Nigeria and

Gulf of Aden: …of these faults forms the Alula-Fartak Trench, in which is found the gulf’s maximum recorded depth of 17,586 feet (5,360 metres). The Sheba Ridge is flanked on both sides by sediment-filled basins that reach depths of 13,000 feet (3,900 metres) at the mouth of the gulf. To the west, the…

alum, any of a group of hydrated double salts, usually consisting of aluminum sulfate, water of hydration, and the sulfate of another element. A whole series of hydrated double salts results from the hydration of the sulfate of a singly charged cation (e.g., K+) and the sulfate of any one of a

Freshwater: It lies close to Alum Bay, notable for its many-coloured sandstone cliffs and for The Needles, a group of chalk sea stacks.

San Jose: The contemporary city: The 720-acre (290-hectare) Alum Rock Park (1872), on the eastern edge of the city, is California’s oldest municipal park. The city abounds in flower gardens, notably the Municipal Rose Garden and Overfelt Gardens. San Jose is home to the Sharks, the Bay Area’s professional ice hockey team. Several…

coral-bells, (Heuchera sanguinea), hardy garden perennial, of the saxifrage family (Saxifragaceae), native to North America from Mexico to the Arctic. Coral-bells is a compact, bushy plant growing in tufts, with flower stems about 45 centimetres (18 inches) tall. It has spikes covered with pendant

alunite, a widespread rock-forming sulfate mineral that occupies pockets or seams in volcanic rocks such as rhyolites, trachytes, and andesites, where it presumably formed through their chemical reaction with escaping sulfurous vapours. It has been used as a source of potash (during World War I)

Alumbrado, a follower of a mystical movement in Spain during the 16th and 17th centuries. Its adherents claimed that the human soul, having attained a certain degree of perfection, was permitted a vision of the divine and entered into direct communication with the Holy Spirit. From this state the

alum, any of a group of hydrated double salts, usually consisting of aluminum sulfate, water of hydration, and the sulfate of another element. A whole series of hydrated double salts results from the hydration of the sulfate of a singly charged cation (e.g., K+) and the sulfate of any one of a

alumina, synthetically produced aluminum oxide, Al2O3, a white or nearly colourless crystalline substance that is used as a starting material for the smelting of aluminum metal. It also serves as the raw material for a broad range of advanced ceramic products and as an active agent in chemical

refractory: Other non-clay-based refractories: Alumina-zirconia-silica (AZS), which is melted and cast into molds or directly into the melting tanks of glass furnaces, is an excellent corrosion-resistant refractory that does not release impurities into the glass melt. AZS is also poured to make tank blocks (also called soldier blocks or sidewall…

aluminum (Al), chemical element, a lightweight silvery white metal of main Group 13 (IIIa, or boron group) of the periodic table. Aluminum is the most abundant metallic element in Earth’s crust and the most widely used nonferrous metal. Because of its chemical activity, aluminum never occurs in the

magnesium processing: History: …in Germany in 1886 by Aluminium und Magnesiumfabrik Hemelingen, based on the electrolysis of molten carnallite. Hemelingen later became part of the industrial complex IG Farbenindustrie, which, during the 1920s and ’30s, developed a process for producing large quantities of molten and essentially water-free magnesium chloride (now known as the…

traditional ceramics: Raw materials: …actually unmodified or chemically modified aluminosilicates (alumina [Al2O3] plus silica), although silica is also used in its pure form. Altogether, the raw materials employed in traditional ceramics fall into three commonly recognized groups: clay, silica, and feldspar. These groups are described below.

industrial glass: Silica-based: Other silica-based glasses are the aluminosilicate glasses, which are intermediate between vitreous silica and the more common soda-lime-silica glasses in thermal properties as well as cost; glass fibres such as E glass and S glass, used in fibre-reinforced plastics and in thermal-insulation wool; and optical glasses containing a multitude of…

niobium processing: Ferroniobium: …reduced to ferroniobium through an aluminothermic process. In this process, the concentrate is mixed with hematite (an iron ore), aluminum powder, and small quantities of fluorspar and lime fluxes in a rotary mixer and then unloaded into steel containers lined with magnesite refractory bricks. Here the charge is placed in…

aluminum (Al), chemical element, a lightweight silvery white metal of main Group 13 (IIIa, or boron group) of the periodic table. Aluminum is the most abundant metallic element in Earth’s crust and the most widely used nonferrous metal. Because of its chemical activity, aluminum never occurs in the

crystal: Growth from the melt: Aluminum arsenide and gallium arsenide have the same crystal structure and the same lattice parameters to within 0.1 percent; they grow excellent crystals on one another. Such materials, known as superlattices, have a repeated structure of n layers of GaAs, m layers of AlAs, n…

Bahrain: Economy: The government-owned Aluminum Bahrain B.S.C. (Alba), one of the world’s largest aluminum smelters, and Bapco have been profitable, but this has provided less incentive for privatization. Bahrain has remained the most important commercial and financial centre in the gulf, although it has faced growing competition from the…

boron: Compounds: Aluminum boride (AlB12), for example, is used in many cases as a substitute for diamond dust for grinding and polishing.

brass: Characteristics of the alloy: …corrosion by seawater; and the aluminum brasses, which provide strength and corrosion resistance where the naval brasses may fail.

aluminum bronze, any of a group of strong, corrosion-resistant alloys of copper containing from 4 to 15 percent aluminum and small amounts of other metals, used to make many machine parts and tools. Because of their golden colour and high tarnish resistance, the alloys are also used for jewelry and

carbide: Ionic carbides: …probably beryllium carbide (Be2C) and aluminum carbide (Al4C3). Beryllium oxide (BeO) and carbon react at 2,000 °C (3,600 °F) to produce the brick-red beryllium carbide, whereas pale yellow aluminum carbide is prepared from aluminum and carbon in a furnace. Aluminum carbide reacts as a typical methanide with water to produce…

cement: High-alumina cement: High-alumina cement is a rapid-hardening cement made by fusing at 1,500 to 1,600 °C (2,730 to 2,910 °F) a mixture of bauxite and limestone in a reverberatory or electric furnace or in a rotary kiln. It also can be made by sintering at…

aluminum: Compounds: … with molten aluminum metal produces aluminum chloride; the latter is the most commonly used catalyst in Friedel-Crafts reactions—i.e., synthetic organic reactions involved in the preparations of a wide variety of compounds, including aromatic ketones and anthroquinone and its derivatives. Hydrated aluminum chloride, commonly known as aluminum chlorohydrate, AlCl3∙H2O, is used…

aluminum: Compounds: …aluminum chloride, commonly known as aluminum chlorohydrate, AlCl3∙H2O, is used as a topical antiperspirant or body deodorant, which acts by constricting the pores. It is one of several aluminum salts employed by the cosmetics industry.

foil: …from tin, now replaced by aluminum for nearly all purposes. The reduction of sheet metal to foil is achieved principally through vertical pressure exerted by finishing-mill rolls combined with horizontal tension applied through mandrels paying out and rewinding the foil stock. Backup rolls mounted above the work rolls of the…

aluminum processing: Foundry alloys: The Aluminum Association of the United States has established systems for classifying foundry and wrought aluminum alloys. Foundry alloys are identified by four-digit numbers, with the first numeral indicating the major alloying element or group of elements (see table; sometimes a letter precedes…

semiconductor device: Semiconductor materials: …from two columns, such as aluminum gallium arsenide (AlxGa1 − xAs), which is a ternary III-V compound, where both Al and Ga are from column III and the subscript x is related to the composition of the two elements from 100 percent Al (x = 1) to 100 percent Ga…

boron group element, any of the six chemical elements constituting Group 13 (IIIa) of the periodic table. The elements are boron (B), aluminum (Al), gallium (Ga), indium (In), thallium (Tl), and nihonium (Nh). They are characterized as a group by having three electrons in the outermost parts of

aluminum: Compounds: With hydrogen, aluminum forms aluminum hydride, AlH3, a polymeric solid from which are derived the tetrohydroaluminates (important reducing agents). Lithium aluminum hydride (LiAlH4), formed by the reaction of aluminum chloride with lithium hydride, is widely used in organic chemistry—e.g., to reduce aldehydes and ketones to primary and secondary alcohols,…

aluminum: Compounds: Aluminum hydroxide, Al(OH)3, is used to waterproof fabrics and to produce a number of other aluminum compounds, including salts called aluminates that contain the AlO−2 group. With hydrogen, aluminum forms aluminum hydride, AlH3, a polymeric solid from which are derived the tetrohydroaluminates (important reducing agents).…

materials science: Materials for ground transportation: …of America (Alcoa) called the aluminum intensive vehicle (AIV), and a similar one at Reynolds Metals, were established to develop materials and processes for making automobile “space frames” consisting of aluminum-alloy rods and die-cast connectors joined by welding and adhesive bonding. Not to be outdone, another aluminum company, Alcan Aluminium…

nitride: Preparation of nitrides: …example, in the preparation of aluminum nitride, AlN. Al2O3 + 3C + N2 → 2AlN + 3CO

alumina, synthetically produced aluminum oxide, Al2O3, a white or nearly colourless crystalline substance that is used as a starting material for the smelting of aluminum metal. It also serves as the raw material for a broad range of advanced ceramic products and as an active agent in chemical

Pilea: …expel their pollen when mature; aluminum plant, or watermelon pilea (P. cadierei), with silvery markings on glossy dark green leaves; Chinese money plant (P. peperomioides), with long petioles (leaf stalks) attached to the centre of the undersides of the round leaves; and friendship plant, or panamiga (P. involucrata), with quilted…

alum: …aluminum sulfate, also known as potassium alum or potash alum, has a molecular formula of K2(SO4)·Al2(SO4)3·24H2O or KAl(SO4)2·12H2O.