aschelminth, a name referring to an obsolete phylum of wormlike invertebrates, mostly of microscopic size. Previously, phylum Aschelminthes included seven diverse classes of animals: Nematoda (or Nemata), Rotifera, Acanthocephala, Gastrotricha, Kinorhyncha (or Echinodera), Nematomorpha, and

aschelminth, a name referring to an obsolete phylum of wormlike invertebrates, mostly of microscopic size. Previously, phylum Aschelminthes included seven diverse classes of animals: Nematoda (or Nemata), Rotifera, Acanthocephala, Gastrotricha, Kinorhyncha (or Echinodera), Nematomorpha, and

Gustave von Aschenbach, fictional character in Thomas Mann’s novel Death in Venice (1912). Aschenbach is a well-respected middle-aged German writer whose life is as disciplined and coldly intellectual as his writing. While on holiday in Venice he falls in love with Tadzio, a beautiful 14-year-old

pregnancy: Symptoms and signs; biological tests: Tests using immature mice (the Aschheim-Zondek test) and immature rats have been found to be extremely accurate. Tests using rabbits (the Friedman test) have been largely replaced by the more rapid and less expensive frog and toad tests.

bryophyte: Ecology and habitats: …of quartz pebbles (the moss Aschisma), and copper-rich substrata (the moss Scopelophila).

Karl Albert Ludwig Aschoff was a German pathologist who recognized the phagocytic (capable of engulfing bacteria and other substances) activity of certain cells found in diverse tissues and named them the reticuloendothelial system (1924). He also described (1904) the inflammatory nodule (called

ascus, a saclike structure produced by fungi of the phylum Ascomycota (sac fungi) in which sexually produced spores (ascospores), usually four or eight in number, are formed. Asci may arise from the fungal mycelium (the filaments, or hyphae, constituting the organism) without a distinct fruiting

supercomputer: Historical development: …of Energy to fund the Accelerated Strategic Computing Initiative (ASCI). The goal of the project was to achieve by 2004 a computer capable of simulating nuclear tests—a feat requiring a machine capable of executing 100 trillion FLOPS (100 TFLOPS; the fastest extant computer at the time was the Cray T3E,…

supercomputer: Historical development: …number of its processors, the ASCI Blue Gene/L, installed in 2005 at Sandia National Laboratories in Livermore, Calif., became the first machine to pass the coveted 100 TFLOPS mark, with a speed of about 135 TFLOPS. Other Blue Gene/L machines, with similar architectures, held many of the top spots on…

supercomputer: Historical development: ASCI Red, built at Sandia National Laboratories in Albuquerque, N.M., with the Intel Corporation, was the first to achieve 1 TFLOPS. Using 9,072 standard Pentium Pro processors, it reached 1.8 TFLOPS in December 1996 and was fully operational by June 1997.

sea squirt, any member of the invertebrate class Ascidiacea (subphylum Urochordata, also called Tunicata), marine animals with some primitive vertebrate features. Sea squirts are primarily sessile (permanently fixed to a surface), potato-shaped organisms found in all seas, from the intertidal zone

sea squirt, any member of the invertebrate class Ascidiacea (subphylum Urochordata, also called Tunicata), marine animals with some primitive vertebrate features. Sea squirts are primarily sessile (permanently fixed to a surface), potato-shaped organisms found in all seas, from the intertidal zone

ASCII, a standard data-encoding format for electronic communication between computers. ASCII assigns standard numeric values to letters, numerals, punctuation marks, and other characters used in computers. Before ASCII was developed, different makes and models of computers could not communicate

ASCII art, computer text art created with ASCII (American Standard Code For Information Interchange) code. ASCII art uses ASCII characters to produce images ranging from simple and functional emoticons to elaborate works of art. The ASCII code was established by the American National Standards

ascites, accumulation of fluid in the peritoneal cavity, between the membrane lining the abdominal wall and the membrane covering the abdominal organs. The most common causes of ascites are cirrhosis of the liver, heart failure, tumours of the peritoneal membranes, and escape of chyle (lymph laden

asclepiad, Greek lyric verse later used by Latin poets such as Catullus, Horace, and Seneca. The asclepiad consisted of an aeolic nucleus, a choriamb to which were added more choriambs and iambic or trochaic elements at the end of each line. A version with four choriambs is known as the greater

Asclepiadoideae, the milkweed subfamily of the flowering-plant family Apocynaceae (order Gentianales), including more than 214 genera and about 2,400 species of tropical herbs or shrubby climbers, rarely shrubs or trees. It was formerly treated as its own family (Asclepiadaceae). However, molecular

Asclepiades Of Bithynia was a Greek physician who established Greek medicine in Rome. His influence continued until Galen began to practice medicine in Rome in ad 164. He opposed the humoral doctrine of Hippocrates and instead taught that disease results from constricted or relaxed conditions of

Asclepiadoideae, the milkweed subfamily of the flowering-plant family Apocynaceae (order Gentianales), including more than 214 genera and about 2,400 species of tropical herbs or shrubby climbers, rarely shrubs or trees. It was formerly treated as its own family (Asclepiadaceae). However, molecular

milkweed, (genus Asclepias), genus of about 140 species of herbaceous perennial flowering plants belonging to the dogbane family Apocynaceae (formerly in Asclepiadaceae). Milkweeds are found throughout North and South America, and several are cultivated as ornamentals. Many milkweed butterflies,

Asclepiadoideae: Common milkweed (Asclepias syriaca) and bloodflower (A. curassavica) often are cultivated as ornamentals. The butterfly weed (A. tuberosa) of North America has bright orange flowers. Hoya carnosa, which is commonly called wax plant because of its waxy white flowers, is often grown indoors as a pot plant. Several succulent plants—such…

milkweed: Major species: curassavica), and showy milkweed (A. speciosa) often are cultivated as ornamentals and to attract butterflies. The butterfly weed (A. tuberosa) of North America has bright orange flowers and is an important butterfly host plant. Urban and agricultural development has led to a decline in both wild milkweeds…

Asclepiadoideae: Common milkweed (Asclepias syriaca) and bloodflower (A. curassavica) often are cultivated as ornamentals. The butterfly weed (A. tuberosa) of North America has bright orange flowers. Hoya carnosa, which is commonly called wax plant because of its waxy white flowers, is often grown indoors as a

butterfly weed, (Asclepias tuberosa), North American plant of the dogbane family (Apocynaceae), a stout rough-haired perennial with long roots. The erect, somewhat branching stem grows up to 1 metre (3 feet) tall and has linear, alternately arranged leaves. In midsummer it bears numerous clusters

Asclepigenia was a Greek philosopher of the Neo-Platonist school, teacher, and lecturer. After the death of her father, Plutarchus, Asclepigenia was active in perpetuating the eastern version of Platonism, in cooperation with her brother, Hiero. Upon the succession of Proclus as head of the school

Asclepius, Greco-Roman god of medicine, son of Apollo (god of healing, truth, and prophecy) and the mortal princess Coronis. The Centaur Chiron taught him the art of healing. At length Zeus (the king of the gods), afraid that Asclepius might render all men immortal, slew him with a thunderbolt.

Asclepius: …his usual attribute was a staff with a serpent coiled around it. This staff is the only true symbol of medicine. A similar but unrelated emblem, the caduceus, with its winged staff and intertwined serpents, is frequently used as a medical emblem but is without medical relevance since it represents…

ascocarp, fruiting structure of fungi of the phylum Ascomycota (kingdom Fungi). It arises from vegetative filaments (hyphae) after sexual reproduction has been initiated. The ascocarp (in forms called apothecium, cleistothecium [cleistocarp], or perithecium) contain saclike structures (asci) that

Ascoli Piceno, city, Marche regione, central Italy. Ascoli Piceno lies at the confluence of the Tronto and Castellano rivers. The ancient centre of the Picenes (early inhabitants of the Adriatic coast), it was conquered in the 3rd century bc by the Romans, who knew it as Asculum Picenum. After 1006

Graziadio Isaia Ascoli was an Italian linguist who pioneered in dialect studies, emphasized the importance of studying living vernaculars, and prepared a model classification of Italian dialects. Ascoli did not receive any formal higher education, but he wrote his first major work, on Oriental

fungus: Form and function of lichens: For example, ascolichens (lichens in which the dominant mycobiont is an ascomycete) form fruits called ascocarps that are similar to those of free-living ascomycetes, except that the mycobiont’s fruits are capable of producing spores for a longer period of time. The algal symbiont within the lichen thallus…

ascocarp, fruiting structure of fungi of the phylum Ascomycota (kingdom Fungi). It arises from vegetative filaments (hyphae) after sexual reproduction has been initiated. The ascocarp (in forms called apothecium, cleistothecium [cleistocarp], or perithecium) contain saclike structures (asci) that

ascocarp, fruiting structure of fungi of the phylum Ascomycota (kingdom Fungi). It arises from vegetative filaments (hyphae) after sexual reproduction has been initiated. The ascocarp (in forms called apothecium, cleistothecium [cleistocarp], or perithecium) contain saclike structures (asci) that

fungus: Annotated classification: Order Saccharomycetales (ascomycete yeasts) Saprotrophic or pathogenic in plants and humans; cell walls lack chitin; asci form singly or in chains; example genera include Saccharomyces, Candida, Dipodascopsis, and Metschnikowia. Subphylum Pezizomycotina

poison: Mycotoxins: …of one of two classes: Ascomycetes, or the sac fungi, and the Deuteromycetes, or the imperfect fungi (i.e., fungi in which no sexual reproductive stages are known). The large toxic mushrooms, or toadstools, are mostly members of the class Basidiomycetes, although some Ascomycetes, such as the poisonous false morel (Gyromitra…

Ascomycota, a phylum of fungi (kingdom Fungi) characterized by a saclike structure, the ascus, which contains four to eight ascospores in the sexual stage. The sac fungi are separated into subgroups based on whether asci arise singly or are borne in one of several types of fruiting structures, or

sponge: Water-current system: …and the development of canals—ascon, sycon, and leucon. The simplest, or ascon, type, found only in certain primitive genera of the Calcarea (e.g., Leucosolenia), is characterized by an arrangement of choanocytes around a central cavity that directly communicates with the osculum. The walls of these sponges are thin, lack…

Switzerland: Urban settlements: …Alps of Ticino, Locarno and Ascona developed on the delta of the Maggia River. Many settlements evolved from their distinct sites. For example, Fribourg (founded in 1157) and Bern (1191) were established at strategic river crossings. Fribourg was sited on a loop of the entrenched Sarine River where a key…

marine ecosystem: Benthos: For example, Ascophyllum spores cannot attach to rock in even a gentle ocean surge; as a result this plant is largely restricted to sheltered shores. The fastest-growing plant—adding as much as 1 metre per day to its length—is the giant kelp, Macrocystis pyrifera, which is found on…

meat processing: Curing and smoking: Sodium erythorbate or ascorbate is another common curing additive. It not only decreases the risks associated with the use of nitrite but also improves cured meat colour development. Other common additives include alkaline phosphates, which improve the juiciness of meat products by increasing their water-holding…

vitamin C, water-soluble, carbohydrate-like substance that is involved in certain metabolic processes of animals. Although most animals can synthesize vitamin C, it is necessary in the diet of some, including humans and other primates, in order to prevent scurvy, a disease characterized by soreness

transition metal: Biological functions of transition metals: …copper-containing enzymes; examples are (1) ascorbic acid oxidase (an oxidase is an oxidizing enzyme), which contains eight atoms of copper per molecule; it is widely distributed in plants and microorganisms; (2) cytochrome oxidase, which contains heme and copper in a 1:1 ratio; (3) tyrosinases, which catalyze the formation of melanin…

beekeeping: Diseases: … is caused by the fungus Ascosphaera apis. The larvae victims of this disease have a chalky white appearance. Stonebrood, which affects both brood and adults, is also caused by a fungus, Aspergillus flavus, which can usually be isolated from bees that have stonebrood.

fungus: Form and function of lichens: Spores of lichen fungi (ascospores) are of extremely varying sizes and shapes; e.g., Pertusaria has one or two large spores in one ascus (saclike bodies containing the ascospores), and Acarospora may have several hundred small spores per ascus. Although in most species the ascospore generally has one nucleus, it…

Ascot, locality, Windsor and Maidenhead unitary authority, geographic and historic county of Berkshire, England, known for its racecourse on Ascot Heath. The Royal Ascot meeting (initiated in 1711 by Queen Anne) lasts four days each June and is traditionally attended by the British sovereign. A

Ascot: …lent its name to the ascot, a type of broad neck scarf. Its principal event is the Ascot Gold Cup, established in 1807 and run over 2.5 miles (4 km) by horses more than three years old.

Ascot: Its principal event is the Ascot Gold Cup, established in 1807 and run over 2.5 miles (4 km) by horses more than three years old.

crustacean: Annotated classification: Order Ascothoracica Cretaceous to present; parasites on sea anemones and echinoderms; body typically enclosed in a bivalved carapace; some with segmented abdomen and caudal furca; others distorted by outgrowths of the gut and ovary, giving a bushlike appearance; males dwarfed, living in mantle cavities of females;…

social status: Status may be ascribed—that is, assigned to individuals at birth without reference to any innate abilities—or achieved, requiring special qualities and gained through competition and individual effort. Ascribed status is typically based on sex, age, race, family relationships, or birth, while achieved status may be based on education,…

ascus, a saclike structure produced by fungi of the phylum Ascomycota (sac fungi) in which sexually produced spores (ascospores), usually four or eight in number, are formed. Asci may arise from the fungal mycelium (the filaments, or hyphae, constituting the organism) without a distinct fruiting

autism spectrum disorder (ASD), any of a group of neurobiological disorders that are characterized by deficits in social interaction and communication and by atypical behaviors, interests, and activities. In 1911 Swiss psychiatrist Eugen Bleuler coined the term autism (from the Greek autos, meaning

Seeds on Ice: Seeds on Ice transcript: …have a very special guest, Åsmund Asdal, who is the Seed Vault coordinator in Norway. Welcome, Åsmund. Thank you so much for sharing your time with us today. It is an honor to have you.

World War II: The Atlantic and the Mediterranean, 1940–41: …vessels had the ASDIC (Anti-Submarine Detection Investigation Committee) device to detect submerged U-boats. By the spring of 1941, under the guidance of Admiral Karl Dönitz, the U-boat commanders were changing their tactic of individual operation to one of wolf-pack attacks: groups of U-boats, disposed in long lines, would rally…

Spain: Visigothic Spain to c. 500: …years, the Suebi and the Asding Vandals settled in the northwestern province of Galicia (Gallaecia). The Siling Vandals occupied Baetica in the south, and the Alans, an Iranian people, settled in the central provinces of Lusitania and Carthaginiensis. For the time being, only Tarraconensis remained entirely under Roman control.

Spain: Visigothic Spain to c. 500: …years, the Suebi and the Asding Vandals settled in the northwestern province of Galicia (Gallaecia). The Siling Vandals occupied Baetica in the south, and the Alans, an Iranian people, settled in the central provinces of Lusitania and Carthaginiensis. For the time being, only Tarraconensis remained entirely under Roman control.

Albanian literature: …period are Asdren (acronym of Aleks Stavre Drenova), a poet; Çajupi (in full Andon Zako Çajupi), a poet and playwright; Ernest Koliqi, a short-story writer, poet, and novelist; Ndre Mjeda, a poet and linguist; and Migjeni (acronym of Milosh Gjergj Nikolla), a poet and novelist.

European Space Agency (ESA), European space and space-technology research organization founded in 1975 from the merger of the European Launcher Development Organisation (ELDO) and the European Space Research Organisation (ESRO), both established in 1964. Members include Austria, Belgium, the Czech

Amalgamated Engineering and Electrical Union: The AEU’s forerunner was the Amalgamated Society of Engineers, a powerful craft union formed in 1851 through a merger with nine other unions. The AEU began to organize on industrial lines in the 1920s as crafts gave way to mass production. Despite a 40 percent membership decline in the 1980s,…

Indra Nooyi: …firm Asea Brown Boveri (now ABB).

ASEAN, international organization established by the governments of Indonesia, Malaysia, the Philippines, Singapore, and Thailand in 1967 to accelerate economic growth, social progress, and cultural development and to promote peace and security in Southeast Asia. Brunei joined in 1984, followed by

East Asian Economic Group: …took the form of the ASEAN (Association of Southeast Asian Nations) Plus Three (APT) framework. Though the APT framework preceded the Asian financial crisis (it emerged from the Asia-Europe meetings), most consider the APT framework “the EAEG by another name.”

ASEAN Regional Forum (ARF), the first regionwide Asia-Pacific multilateral forum for official consultations on peace and security issues. An outgrowth of the annual ministerial-level meeting of members of the Association of Southeast Asian Nations (ASEAN) and the states serving as ASEAN’s “dialogue

Asseb, Red Sea port, southeastern Eritrea. It lies at the entrance of Asseb Bay and is Eritrea’s second most important port (after Massawa). Formerly a terminus of caravan routes across the arid Denakil Plain, the Asseb coastal strip was acquired by Italian shipping interests in 1869 and in 1882

aseismic ridge, a long, linear and mountainous structure that crosses the basin floor of some oceans. Earthquakes do not occur within aseismic ridges, and it is this feature that distinguishes them from oceanic spreading centres. Most aseismic ridges are constructed by volcanism from a hot spot and

Asela, town, south-central Ethiopia. It lies west of Mount Chilalo on a high plateau overlooking Lake Ziway in the Great Rift Valley. The town is an important trading centre for the surrounding livestock and lumbering region. An all-weather road connects it with Nazret to the north. Pop. (2007

Asela, town, south-central Ethiopia. It lies west of Mount Chilalo on a high plateau overlooking Lake Ziway in the Great Rift Valley. The town is an important trading centre for the surrounding livestock and lumbering region. An all-weather road connects it with Nazret to the north. Pop. (2007

fungus: Annotated classification: Order Asellariales Endosymbiotic, found in the digestive tracts of arthropods; thallus branched, septate, attached by basal coenocytic cell; asexual reproduction by arthrospores; example genera include Asellaria and Orchesellaria. Phylum Ascomycota (sac fungi)

Gaspare Aselli was an Italian physician who contributed to the knowledge of the circulation of body fluids by discovering the lacteal vessels. Aselli became professor of anatomy and surgery at the University of Pavia and practiced at Milan. His discovery of the lacteals (lymph vessels that take up

Gaspare Aselli was an Italian physician who contributed to the knowledge of the circulation of body fluids by discovering the lacteal vessels. Aselli became professor of anatomy and surgery at the University of Pavia and practiced at Milan. His discovery of the lacteals (lymph vessels that take up

annalist: …the late 2nd century bc: Sempronius Asellio, influenced by the contemporary Greek historian Polybius, distinguished between annals, which recount the past in a straightforward narrative, and histories, which tell of contemporary events and include serious critical analysis of events and motives. Historians in the 2nd and 1st centuries bc who…

Bulgarian literature: …or Silver, age of the Asen and Shishman dynasties excelled in sheer graphic virtuosity (script, layout, illumination, binding) of its manuscripts, such as the Vatican Manasses Chronicle of 1345 and the London Tsar Ivan Aleksandŭr Gospel of 1356. In content, too, Byzantine influences and translations from the Greek continued to…

Ivan Asen I was the tsar of the Second Bulgarian empire from 1186 to 1196, during one of the most brilliant periods of the restored Bulgarian nation. He and his brother Peter II were founders of the Asen dynasty, which survived until the latter half of the 13th century. Asen was a descendant of

Latin American dance: Folk and popular dances: …and seguidilla was described as asentado, or seated: dancers maintained a bit of flexion in the legs while keeping the torso upright. In the Americas the quality of weight, or grounding, that this position gave the man’s body as he danced was amplified as he mimed motifs from daily work…

land reform: Latin America: …selected, they were organized into asentamientos, or settlement groups. The group elected a committee to take charge of settlement. The members cultivated the land as a team for three to five years. Meanwhile they received training and guidance in social participation, decision making, and modern farming. Upon completion of the…

surgery: Present-day surgery: Asepsis, the freedom from contamination by pathogenic organisms, requires that all instruments and dry goods coming in contact with the surgical field be sterilized. This is accomplished by placing the materials in an autoclave, which subjects its contents to a period of steam under pressure.…

lumbar puncture: Viral meningitis can be differentiated from bacterial meningitis by the type of white blood cells identified in the CSF. In addition, culturing a sample of the fluid to determine whether bacteria are present is an effective way to distinguish between different causes of meningitis. Fluctuations…

avascular necrosis, death of bone tissue caused by a lack of blood supply to the affected area. Avascular necrosis most commonly affects the epiphyses (ends) of the femur (thigh bone); other commonly affected bones include those of the upper arm, the shoulder, the knee, and the ankle. Avascular

food preservation: Aseptic processing: The aseptic process involves placing a sterilized product into a sterilized package that is then sealed under sterile conditions. It began in 1914 with the development of sterile filters for use in the wine industry. However, because of unreliable machinery, it remained commercially…

yamim noraʾim, in Judaism, the High Holy Days of Rosh Hashana (on Tishri 1 and 2) and Yom Kippur (on Tishri 10), in September or October. Though the Bible does not link these two major festivals, the Talmud does. Consequently, yamim noraʾim is sometimes used to designate the first 10 days of the

Aseric was the first bishop of Kalocsa, who played an instrumental role in the foundation of the Hungarian state and church. Aseric left the entourage of St. Adalbert (Vojtěch), bishop of Prague, to undertake an evangelizing mission in the Magyar lands. He accompanied Adalbert to Rome in 994–996,

Isis, one of the most important goddesses of ancient Egypt. Her name is the Greek form of an ancient Egyptian word for “throne.” Isis was initially an obscure goddess who lacked her own dedicated temples, but she grew in importance as the dynastic age progressed, until she became one of the most

vegetative reproduction, any form of asexual reproduction occurring in plants in which a new plant grows from a fragment of the parent plant or grows from a specialized reproductive structure (such as a stolon, rhizome, tuber, corm, or bulb). In many plants, vegetative reproduction is a completely

algae: Reproduction and life histories: …female gametes (sex cells), by asexual reproduction, or by both ways.

asexuality, experiencing a complete or partial absence of sexual attraction or finding little interest in engaging in sexual activities with others. Asexuality encompasses a broad spectrum, and people who identify as asexual may experience varying degrees of sexual attraction, ranging from no

African swine fever (ASF), highly contagious and usually fatal viral disease of swine that is characterized by high fever, lesions, leukopenia (abnormally low count of white blood cells), elevated pulse and respiration rate, and death within four to seven days after the onset of fever. The virus

Mullā Ṣadrā: …famous of which was his Asfār (“Journeys”). Asfār contains the bulk of his philosophy, which was influenced by a personal mysticism bordering on the ascetic that he experienced during a 15-year retreat at Kahak, a village near Qom, Iran.

asfarvirus, any virus belonging to the family Asfarviridae. This family consists of one genus, Asfivirus, which contains the African swine fever virus. Asfarviruses have enveloped virions (virus particles) that are approximately 175–215 nm (1 nm = 10−9 metre) in diameter. An icosahedral capsid (the

asfarvirus, any virus belonging to the family Asfarviridae. This family consists of one genus, Asfivirus, which contains the African swine fever virus. Asfarviruses have enveloped virions (virus particles) that are approximately 175–215 nm (1 nm = 10−9 metre) in diameter. An icosahedral capsid (the

Safi, Atlantic port city, western Morocco. Safi was in turn inhabited by Carthaginians (who named it Asfi), Romans, and Goths and finally by Muslims in the 11th century. It was a ribāṭ (a type of fortified monastery) in the 13th century and was mentioned by the historian Ibn Khaldūn. The Portuguese

asfarvirus: …family consists of one genus, Asfivirus, which contains the African swine fever virus. Asfarviruses have enveloped virions (virus particles) that are approximately 175–215 nm (1 nm = 10−9 metre) in diameter. An icosahedral capsid (the protein shell surrounding the viral nucleic acids) contains linear double-stranded DNA.

Asgard, in Norse mythology, the dwelling place of the gods, comparable to the Greek Mount Olympus. Legend divided Asgard into 12 or more realms, including Valhalla, the home of Odin and the abode of heroes slain in earthly battle; Thrudheim, the realm of Thor; and Breidablik, the home of Balder.

Asgard, in Norse mythology, the dwelling place of the gods, comparable to the Greek Mount Olympus. Legend divided Asgard into 12 or more realms, including Valhalla, the home of Odin and the abode of heroes slain in earthly battle; Thrudheim, the realm of Thor; and Breidablik, the home of Balder.

Eysteinn Ásgrímsson was an Icelandic monk, author of Lilja (“The Lily”), the finest religious poem produced in Roman Catholic Iceland. Records of Ásgrímsson’s life are scant. In 1343 he was imprisoned, probably for thrashing his abbot and perhaps for a breach of chastity as well. In 1349 he was

coal utilization: Mineral (ash) content: Coal contains a variety of minerals in varying proportions that, when the coal is burned, are transformed into ash. The amount and nature of the ash and its behaviour at high temperatures affect the design and type of ash-handling system employed in coal-utilization…

rocket and missile system: Air-to-air: The AA-5 Ash was a large, medium-range radar-guided missile, while the AA-6 Acrid was similar to the Anab but larger and with greater range. The AA-7 Apex, a Sparrow equivalent, and the AA-8 Aphid, a relatively small missile for close-in use, were introduced during the 1970s.…

ash, (genus Fraxinus), genus of 45–65 species of trees or shrubs (family Oleaceae) primarily distributed throughout the Northern Hemisphere. Several species are valuable for their timber and beauty. A few species extend into the tropical forests of Mexico and Java. Most ash trees are small to

Ashcan School, group of American realist painters based in New York City in the early 20th century. The group’s most prominent figures were known as “The Eight.” See Eight,

cinder cone, deposit around a volcanic vent, formed by pyroclastic rock fragments (formed by volcanic or igneous action), or cinders, which accumulate and gradually build a conical hill with a bowl-shaped crater at the top. Cinder cones develop from explosive eruptions of mafic (heavy, dark

coal utilization: Mineral (ash) content: The amount and nature of the ash and its behaviour at high temperatures affect the design and type of ash-handling system employed in coal-utilization plants. At high temperatures, coal ash becomes sticky (i.e., sinters) and eventually forms molten slag. The slag then becomes a hard, crystalline material upon…

ash: Pests and diseases: …to the rapid spread of ash dieback disease (caused by the fungus Chalara fraxinea). In addition to these catastrophic maladies, ash trees are also susceptible to anthracnose, yellows, and rust.