effective atomic number: …observation, since known as the EAN rule, that in a number of metal complexes the metal atom tends to surround itself with sufficient ligands that the resulting effective atomic number is numerically equal to the atomic number of the noble-gas element found in the same period in which the metal…

economic stabilizer: Price flexibility: …introduce the concept of “effective demand.” To pre-Keynesian economists the implied distinction between “effective” and (presumably) “ineffective” demand would have had no analytical meaning. The logic of traditional economic theory suggested two possibilities that might make the price system inoperative: (1) that, in some markets, neither demanders nor suppliers…

rocket: General characteristics and principles of operation: …the exhaust, ve is the effective exhaust velocity (nearly equal to the jet velocity and taken relative to the rocket), and F is force. The quantity m°ve is the propulsive force, or thrust, produced on the rocket by exhausting the propellant,

inertial force, any force invoked by an observer to maintain the validity of Isaac Newton’s second law of motion in a reference frame that is rotating or otherwise accelerating at a constant rate. For specific inertial forces, see centrifugal force; Coriolis force; d’Alembert’s

government economic policy: Incidence of taxation and expenditure: … of a tax and its effective, or final, incidence. The legal incidence is on the person or company who is legally obliged to pay the tax. Effective, or final, incidence refers to who actually ends up paying the tax; if, for example, the whole of a sales tax can be…

telecommunications media: The radio-frequency spectrum: …remote receiving antenna is the effective isotropic radiated power (EIRP), measured in watts per metre squared. To achieve high EIRP the antenna dimensions should be several times larger than the largest transmitted wavelength. For frequencies below the medium frequency (MF) band, where wavelengths range upward from 100 metres (about 330…

effective population size, in genetics, the size of a breeding population, a factor that is determined by the number of parents, the average number of children per family, and the extent to which family size varies from the average. The determination of the effective population size of a breeding

formal logic: Formation rules for PC: …way that there is an effective procedure for determining, again without any reference to interpretation, whether any arbitrary string of symbols is a wff or not. (An effective procedure is one that is “mechanical” in nature and can always be relied on to give a definite result in a finite…

international trade: Measuring the effects of tariffs: The effective rate of protection is a more complex concept: consider that the same product—clothing—costs $100 on international markets. The material that is imported to make the clothing (material inputs) sells for $60. In a free-trade situation, a firm can charge no more than $100 for…

mechanics of solids: Continuum plasticity theory: …1920s developed the concept of effective stress, whereby the stresses that enter a criterion of yielding or failure are not the total stresses applied to the saturated soil or rock mass but rather the effective stresses, which are the difference between the total stresses and those of a purely hydrostatic…

Neptune: The atmosphere: This temperature is called the effective temperature.

formal logic: Formation rules for PC: …way that there is an effective procedure for determining, again without any reference to interpretation, whether any arbitrary string of symbols is a wff or not. (An effective procedure is one that is “mechanical” in nature and can always be relied on to give a definite result in a finite…

information processing: Basic concepts: …components, the receptor and the effector, are input and output mechanisms whose functions are, respectively, to receive symbolic expressions or stimuli from the external environment for manipulation by the processor and to emit the processed structures back to the environment.

nervous system: Organelle systems: …receptors of stimulus and as effectors of response. Receptors include stiff sensory bristles in ciliates and the light-sensitive eyespots of flagellates. Effectors include cilia (slender, hairlike projections from the cell surface), flagella (elongated, whiplike cilia), and other organelles associated with drawing in food or with locomotion.

effector cell, type of cell in the body that carries out a specific activity in response to stimulation. The term effector cell generally is applied to certain cells in the immune system; however, it is sometimes also used to refer to cells in the nervous system that are found at the ends of

Charles Darwin: The patriarch in his home laboratory: The results appeared in The Effects of Cross and Self Fertilization in the Vegetable Kingdom (1876). His next book, The Different Forms of Flowers on Plants of the Same Species (1877), was again the result of long-standing work into the way evolution in some species favoured different male and…

two-step flow model of communication: …fully by Joseph Klapper in The Effects of Mass Communication (1960), which guided mass communication researchers over the next five decades.

occupational disease: The industrial era: …medicine in Britain with his The Effects of the Principal Arts, Trades and Professions . . . on Health and Longevity . . . (1831), which described lung diseases caused by dust that commonly afflicted miners and metal grinders. In 1895 Britain introduced a statutory notification system that required medical…

effects pedal, electronic device, operated by foot, that enhances, distorts, or otherwise alters electrical signals that are transmitted through it and that originate with a musical instrument. Effects pedals are used to change the sound of the instrument, and there are numerous types. Most are

Peter Høeg: …thriller Effekten af Susan (2014; The Susan Effect), centres on a woman who is extremely adept at uncovering secrets.

radio telescope: Filled-aperture telescopes: …filled-aperture radio telescopes include the Max Planck Institut für Radioastronomie 100-metre- (330-foot-) diameter antenna near Effelsberg, Germany; the Australian Commonwealth Scientific and Industrial Research Organization (CSIRO) 64-metre (210-foot) dish near Parkes; and the 76-metre (250-foot) Lovell Telescope at Jodrell Bank in England. These filled-aperture radio telescopes are used for

Justus van Effen was a Dutch essayist and journalist whose straightforward didactic pieces, modelled on foreign examples, had a wholesome influence on the contemporary Dutch fashion of rococo writing. His other occupations included private tutor, secretary at the Netherlands embassy in London (1715

Mehmed Emin Pasha was a physician, explorer, and governor of the Equatorial province of Egyptian Sudan who contributed vastly to the knowledge of African geography, natural history, ethnology, and languages. In 1865 Schnitzer became a medical officer in the Turkish army and used his leisure to

renal system: Arteries and arterioles: …afferent arteriole to become the efferent arterioles carrying blood away from the glomeruli. The afferent arterioles are almost twice as thick as the efferent arterioles because they have thicker muscular coats, but the sizes of their channels are almost the same.

nervous system: Nervous systems: …and sends an outgoing, or efferent, impulse to an efferent neuron, such as a motor neuron. The efferent neuron, in turn, makes contact with an effector such as a muscle or gland, which produces a response.

human sexual activity: Nervous system factors: …come from the cord (efferent nerves) transmitting impulses to activate muscles, and (2) the autonomic system, the primary function of which is the regulation and maintenance of the body processes necessary to life, such as heart rate, breathing, digestion, and temperature control. Sexual response involves the entire nervous system.…

nerve: …categories, namely, sensory (afferent) and motor (efferent). The fibres of these categories and their subdivisions constitute the functional components of the nerves. The combinations of such components vary in the individual cranial nerves; in the spinal nerves they are more uniform.

nervous system: Nervous systems: …or efferent, impulse to an efferent neuron, such as a motor neuron. The efferent neuron, in turn, makes contact with an effector such as a muscle or gland, which produces a response.

calcite: Chemical composition: …reaction is manifested by vigorous effervescence. (The dilution of the HCl usually used is about 90:10 [water:concentrated HCl].) The reactions involved are

Effi Briest, novel by Theodor Fontane, written in 1891–93; published in installments in the literary and political periodical Deutsche Rundschau from October 1894 to March 1895 and in book form in 1895. Known for its deft characterization and accurate portrayal of Brandenburg society, the novel

drug: Receptors: …to bind to a receptor; efficacy (sometimes called intrinsic activity) describes the ability of the drug-receptor complex to produce a physiological response. Together, the affinity and the efficacy of a drug determine its potency.

automobile: Transmission: The efficiency of an automobile engine is highest when the load on the engine is high and the throttle is nearly wide open. At moderate speeds on level pavement, the power required to propel an automobile is only a fraction of this. Under normal driving conditions…

efficiency, in economics and organizational analysis, a measure of the input a system requires to achieve a specified output. A system that uses few resources to achieve its goals is efficient, in contrast to one that wastes much of its input. Efficiency is a favourite objective of economists and

marketing: Efficiency control: Efficiency control involves micro-level analysis of the various elements of the marketing mix, including sales force, advertising, sales promotion, and distribution. For example, to understand its sales-force efficiency, a company may keep track of how many sales calls a representative makes each day,…

gerrymandering: …be represented as an “efficiency gap” between the parties when the difference between wasted votes is divided by the total number of votes cast. The plaintiffs argued that efficiency gaps of 7 percent or greater were legally significant because they were more likely than smaller gaps to persist through…

radiation measurement: Scintillators: …fraction is given the name scintillation efficiency and ranges from about 3 to 15 percent for common scintillation materials. The photon energy (or the wavelength of the light) is distributed over an emission spectrum that is characteristic of the particular scintillation material.

economics: Theory of allocation: …combination is called the “optimal” or “efficient” combination. As a rule, the optimal allocation equalizes the returns of the marginal (or last) unit to be transferred between all the possible uses. In the theory of the firm, an optimum allocation of outlays among the factors is the same for…

metaphysics: Aristotelianism: The notion of an efficient cause has a role in Aristotelianism. As Aristotle put it, it takes a human being, a developed specimen of the kind, to beget a human being. It is, however, a subordinate role and yields pride of place to a different idea—namely, form considered as…

rubber: The cure package: …is known as an “efficient vulcanization” (EV) system and gives products with sulfur interlinks of shorter length. EV products have improved resilience but lower strength.

economics: Financial economics: …changed understanding of the “efficient market hypothesis,” which held that securities prices in an efficient stock market were inherently unpredictable—that is, an investment in the stock market was, for all but insider traders, equivalent to gambling in a casino. (An efficient stock market was one in which all information…

Derek Jacobi: …Grace of Monaco (2014), and Effie Gray (2014). He reteamed with Branagh for the movie adaptations of Cinderella (2015) and Murder on the Orient Express (2017). In between the latter films, he reunited with the Cinderella cast onstage in Branagh’s production of Romeo and Juliet (2016).

crurotarsan: …that some forms, such as Effigia okeeffeae, were bipedal. (E. okeeffeae evolved some 80 million years before the first bipedal dinosaurs appeared.) Most crurotarsan lineages died out during the end-Triassic extinction event, and their demise has been attributed to a combination of volcanic eruptions and climatic changes. Furthermore, many

metalwork: England: There remain in England 10 effigies cast in bronze over a period of two centuries (1290–1518), among them some of the finest examples of figure work and metal casting to be found in Europe. In several instances, particulars for the contracts of the tombs survive, together with the names of…

mask: Funerary and commemorative uses: …revived in the making of effigy masks for the royalty and nobility of Europe from the late Middle Ages through the 18th century. Painted and with human hair, these masks were attached to a dummy dressed in state regalia and were used for display, processionals, or commemorative ceremonies.

effigy mound, earthen mound in the form of an animal or bird found throughout the north-central United States. Prehistoric Native Americans built a variety of earth berm structures in addition to effigy mounds, including conical, linear, and flat-topped mounds. Although other mound forms preceded

Effigy Mounds National Monument, area of 4 square miles (10 square km) containing numerous ancient Native American burial and ceremonial mounds in northeastern Iowa, U.S., on the Mississippi River, a few miles north of McGregor. Established in 1949 and located on bluffs overlooking the river, the

Effingham, city, seat (1860) of Effingham county, east-central Illinois, U.S. It lies near the Little Wabash River, about 65 miles (105 km) southeast of Decatur. Settled about 1814 by farmers, the community grew slowly as pioneers moved westward along the Cumberland (National) Road, which had been

massage: …light or hard stroking (effleurage), which relaxes muscles and improves circulation to the small surface blood vessels and is thought to increase the flow of blood toward the heart; compression (petrissage), which includes kneading, squeezing, and friction and is useful in stretching scar tissue, muscles, and tendons so that…

efflorescence, spontaneous loss of water by a hydrated salt, which occurs when the aqueous vapor pressure of the hydrate is greater than the partial pressure of the water vapour in the air. For example, because the vapour pressures of washing soda (Na2CO3·10H2O) and Glauber’s salt (Na2SO4·10H2O)

mining: Evaporation of effluents: Increasing attention has been devoted to the extraction of salts from brines discharged as effluent after the distillation of fresh water from seawater. By using these brines for the extraction of minerals, several important advantages are gained. First, the cost of pumping is carried…

wastewater treatment: Effluent polishing: For the removal of additional suspended solids and BOD from secondary effluent, effluent polishing is an effective treatment. It is most often accomplished using granular media filters, much like the filters used to purify drinking water. Polishing filters are usually built as prefabricated…

wastewater treatment: Wastewater treatment and disposal: Effluent standards, on the other hand, pertain directly to the quality of the treated wastewater discharged from a sewage treatment plant. The factors controlled under these standards usually include biochemical oxygen demand (BOD), suspended solids, acidity, and coliforms.

electromagnetism: Emergence of the modern sciences of electricity and magnetism: …which then left an “effluvium,” or atmosphere, around the body. The language is quaint, but, if the “humour” is renamed “charge” and the “effluvium” renamed “electric field,” Gilbert’s notions closely approach modern ideas.

electromagnetism: Emergence of the modern sciences of electricity and magnetism: …which then left an “effluvium,” or atmosphere, around the body. The language is quaint, but, if the “humour” is renamed “charge” and the “effluvium” renamed “electric field,” Gilbert’s notions closely approach modern ideas.

Effon-Alaiye, town, Ekiti state, southwestern Nigeria, in the Yoruba Hills, at the intersection of roads from Ilesha, Ondo, and Ado-Ekiti. It was probably founded in the late 19th century, when both the Ilesha and Effon belonged to the Ekiti–Parapo, a Yoruba confederation that fought against the

French literature: Drama: …the corruption of financiers in Les Effrontés (1861; “The Shameless Ones”) is as trenchant as comparable portraits in the Naturalist novelists.

gas: Effusion: Consider the system described above in the calculation of gas pressure, but with the area A in the container wall replaced with a small hole. The number of molecules that escape through the hole in time t is equal to (1/2)(N/V)vz(At). In this case,…

volcano: Two 20th-century eruptions: …of Mauna Loa (illustrative of effusive volcanism).

Efik, people inhabiting the lower Cross River in Cross River state, Nigeria. Their language is the main dialect and language of the Efik-Ibibio group of the Benue-Congo branch of Niger-Congo languages. It is widely spoken as a lingua franca throughout the Cross River region. The Efik, who are

Efik: …dialect and language of the Efik-Ibibio group of the Benue-Congo branch of Niger-Congo languages. It is widely spoken as a lingua franca throughout the Cross River region. The Efik, who are culturally and linguistically related to the Ibibio, migrated down the Cross River during the first half of the 17th…

English Football League (EFL), English professional football (soccer) organization. The league was formed in 1888, largely through the efforts of William McGregor, known afterward as the “father of the league.” Twelve of the strongest professional clubs of the time joined in the league, and the

Walachia, principality on the lower Danube River, which in 1859 joined Moldavia to form the state of Romania. Its name is derived from that of the Vlachs, who constituted the bulk of its population. Walachia was bounded on the north and northeast by the Transylvanian Alps, on the west, south, and

eflornithine, drug used to treat late-stage African trypanosomiasis (sleeping sickness). Eflornithine is effective only against Trypanosoma brucei gambiense, which causes Gambian (or West African) sleeping sickness. It is not effective against T. brucei rhodesiense, which causes Rhodesian (or East

ephod, part of the ceremonial dress of the high priest of ancient Israel described in the Old Testament (Ex. 28:6–8; 39:2–5). It was worn outside the robe and probably kept in place by a girdle and by shoulder pieces, from which hung the breast piece (or pouch) containing the sacred lots

Profiat Duran was a Jewish philosopher and linguist, the author of a devastating satire on medieval Christianity and of a notable work on Hebrew grammar. Duran was the descendant of a scholarly Jewish family of southern France. He was educated in Germany and then took a position as tutor with a

Profiat Duran was a Jewish philosopher and linguist, the author of a devastating satire on medieval Christianity and of a notable work on Hebrew grammar. Duran was the descendant of a scholarly Jewish family of southern France. He was educated in Germany and then took a position as tutor with a

Effon-Alaiye, town, Ekiti state, southwestern Nigeria, in the Yoruba Hills, at the intersection of roads from Ilesha, Ondo, and Ado-Ekiti. It was probably founded in the late 19th century, when both the Ilesha and Effon belonged to the Ekiti–Parapo, a Yoruba confederation that fought against the

improvised explosive device: Components: …some Shīʿite militia groups used explosively formed projectiles (EFPs)—an extremely lethal form of shaped charge supplied by Iran—to destroy even the most heavily armoured vehicles, such as M1 Abrams tanks.

ifrit, in Islamic mythology and folklore, a class of powerful malevolent supernatural beings. The exact meaning of the term ifrit in the earliest sources is difficult to determine. It does not occur in pre-Islamic poetry and is only used once in the Qurʾān, in the phrase “the ifrit of the jinn”

Marina Ivanovna Tsvetayeva was a Russian poet whose verse is distinctive for its staccato rhythms, originality, and directness and who, though little known outside Russia, is considered one of the finest 20th-century poets in the Russian language. Tsvetayeva spent her youth predominantly in Moscow,

Who were the Von Erich wrestling family?: Kevin Von Erich (1957– ): …by Sean Durkin and starring Zac Efron, Jeremy Allen White, and Harris Dickinson as Kevin, Kerry, and David Von Erich, respectively.

Slovakia: History of Slovakia: …over the expansion of the European Financial Stability Facility (EFSF), the euro zone’s primary bailout mechanism, toppled the Radičová government. After the government’s collapse, Radičová opened talks with Smer, and Fico pledged his support for the EFSF in exchange for early elections.

money: Electronic money: First, depositors can use electronic funds transfers (EFTs) to withdraw currency from their accounts using automated teller machines (ATMs). In this way an ATM withdrawal works like a debit card. ATMs also allow users to deposit checks into their accounts or repay bank loans. While they do not replace…

European Free Trade Association (EFTA), group of four countries—Iceland, Liechtenstein, Norway, and Switzerland—organized to remove barriers to trade in industrial goods among themselves, but with each nation maintaining its own commercial policy toward countries outside the group. Headquarters are

Dan Andersson: …published after his death in Efterskörd (1929; “Late Harvest”) and Tryckt och otryckt (1942; “Printed and Unprinted”).

Peter Seeberg: …Seeberg’s collection of short stories, Eftersøgningen (1962; “The Search”). These characters act but lack all awareness of the motives of their actions.

Bulgarian Orthodox Church: …Turks (1393), the last patriarch, Eftimi, was exiled and the patriarchate ceased to exist. For nearly five centuries Bulgaria was under Turkish domination, and the church was administered by the patriarch of Constantinople through a Greek clergy. The struggle for an independent Bulgarian church, begun late in the 18th century,…

African literature: English: Flora Nwapa wrote the novel Efuru (1966), the story of a talented, brilliant, and beautiful woman who, living in a small community, is confined by tradition. A woman’s fundamental role, childbearing, is prescribed for her, and if she does not fulfill that role she suffers the negative criticism of members…

stem cell: Embryonic germ cells: Embryonic germ (EG) cells, derived from primordial germ cells found in the gonadal ridge of a late embryo, have many of the properties of embryonic stem cells. The primordial germ cells in an embryo develop into stem cells that in an adult…

Tefé, city and river port, central Amazonas estado (state), northwestern Brazil. Founded by missionaries as Nogueira in the 17th century and also called Ega at one time, Tefé lies on the left (north) bank of the portion of the Amazon River known as the Solimões, on the lake formed by the mouth of

Egadi Islands, small mountainous group of islets belonging to Italy, in the Mediterranean just off the western coast of Sicily, with a total area of 15 square miles (39 square km). The principal islands are Favignana, the largest (7 square miles [18 square km]), Levanzo, and Marettimo. In the

keffiyeh: Variations: …thick black cord called the ʿiqāl is tied around the ghutrah to secure it to the head. This variation is worn primarily in the Gulf States, including Bahrain, Qatar, and the United Arab Emirates. In Iran the chafiyeh is worn atop the head and is typically checkered in a dark…

egalitarianism, the belief in human equality, especially political, social, and economic equality. Egalitarianism has been a driving principle of many modern social movements, including the Enlightenment, feminism, civil rights efforts, and the establishment of international human rights. Given

Jennifer Egan is an American novelist and short-story writer whose diverse works have garnered great critical acclaim. Egan was born in Chicago but grew up in San Francisco. She attended the University of Pennsylvania and then went to England to study at St. John’s College, Cambridge. During this

Pierce Egan, the Elder was a sporting writer whose works were considered indispensable reading for English men-about-town in the early 19th century. Egan made his reputation as a boxing reporter. His best-known work is Boxiana (1818–24), a racy but accurate account of the lives of famous pugilists.

Terrassa, city, Barcelona provincia (province), in the comunidad autónoma (autonomous community) of Catalonia, in northeastern Spain. Terrassa lies along the coastal plain, just northwest of Barcelona city. The successor of Egara, a Roman town, it became in ad 450 an important episcopal see with a

António Egas Moniz was a Portuguese neurologist and statesman who was the founder of modern psychosurgery. With Walter Hess he was awarded the 1949 Nobel Prize for Physiology or Medicine for the development of prefrontal leucotomy (lobotomy) as a radical therapy for certain psychoses, or mental

Abeokuta: …hunter and leader of the Egba refugees who fled from the disintegrating Oyo empire. The town was also settled by missionaries (in the 1840s) and by Sierra Leone Creoles, who later became prominent as missionaries and as businessmen. Abeokuta’s success as the capital of the Egba and as a link…

Yoruba: …of voluntary associations, including the egbe, a male recreational association; the aro, a mutual-aid association of farmers; and the esusu, whose members contribute a fixed amount of money and from which they can receive loans. Political authority is vested in the oba and a council of chiefs; constituent towns each…

Obafemi Awolowo: …while there he founded the Egbe Omo Oduduwa (Yoruba: “Society of the Descendants of Oduduwa”) to promote the culture and unity of the Yoruba people, one of the three largest ethnic groups in colonial Nigeria, and to ensure a secure future for them. During that period Awolowo also wrote the…

Egbert was the king of the West Saxons from 802 to 839, who formed around Wessex a kingdom so powerful that it eventually achieved the political unification of England (mid-10th century). The son of Ealhmund, king in Kent in 784 and 786, Egbert was a member of a family that had formerly held the

Calabar: …of Old Calabar by the Ekpe secret society, which was controlled by the towns’ merchant houses.

Ekoi: …of British colonial administration, the egbo was a prominent Ekoi secret society that had strong social regulatory functions as well as influence in religious matters. Members of the egbo used a form of ideographic writing called nsibidi, variations of which were formerly found among other ethnic groups in southeastern Nigeria.

esophagogastroduodenoscopy (EGD), diagnostic procedure in which an endoscope is passed through the esophagus, stomach, and duodenum in order to visually examine the tissues for evidence of disease. The flexible fibre-optic endoscope contains special channels, which facilitate biopsy, and usually

Aegean Sea, an arm of the Mediterranean Sea located between the Greek peninsula on the west and Asia Minor on the east. About 380 miles (612 km) long and 186 miles (299 km) wide, it has a total area of some 83,000 square miles (215,000 square km). The Aegean is connected through the straits of the

Eskimo-Aleut languages: Alphabets and orthography: …was published in 1742 by Hans Egede, a Dano-Norwegian missionary to Greenland. It was printed in the current Roman alphabet.

Greenland: History of Greenland: IA leader Múte Bourup Egede became prime minister, the steward of IA-Naleraq majority coalition government that was supported by Atassut.

Jan Egeland is a Norwegian public official who served as head of United Nations (UN) humanitarian and relief efforts from 2003 to 2006. Egeland earned a bachelor’s degree in political science from the University of Oslo (1982) and studied as a Fulbright scholar at the University of California,

rederijkerskamer: The Egelantier (Dutch: Wild Briar) and the Wit Lavendel (Dutch: White Lavender), however, remained popular into the 17th century because of the leading Renaissance poets associated with them in Amsterdam.

Western sculpture: Central Europe: Paul Egell was a pupil of Permoser in Dresden at the time of the Zwinger decorations, and in 1721 he was appointed court sculptor at Mannheim. Egell’s elongated and refined Baroque figures were an effective counter to the Classicism of Donner, and his personality was…