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fatigue In engineering, manifestation of progressive fracture in a solid under cyclic loading, as in the case of a metal strip that ruptures after repeated bending back and forth (see metal fatigue). Fatigue fracture begins with one or several cracks that spread in the course of repeated applica¬ tion of forces until complete rupture suddenly occurs when the small unaffected portion is too weak to sustain the load. See also ductility, test¬ ing MACHINE.
Fatima Vfa-to-msX Village in central Portugal, site of a shrine dedicated to the Virgin Mary. From May to October 1917, three peasant children reported a vision of a woman who identified herself as the Lady of the Rosary. On October 13, a crowd of about 70,000 witnessed an amazing solar phenomenon just after the children had seen their vision. The first national pilgrimage to the site occurred in 1927. Construction of a basilica started in 1928; now flanked by retreat houses and hospitals, it faces a square where many miraculous cures have been reported.
Fatimah or Fatima Yfa-ts-moN (b. c. 605, Mecca, Arabia—d. 633, Medina) Daughter of Muhammad and the object of veneration in ShTite Islam. In 622 she emigrated with her father from Mecca to Medina, where she married her cousin 'Au. Their sons, Hasan and al-HusAYN ibn 'AlI, are considered by Shl'ites to be the rightful inheritors of the tradition of Muhammad. Fatimah’s marriage was unhappy, but she and her husband were reconciled by the Prophet, and she cared for her father in his last illness (632). She clashed with his successor, AbO Bakr, over property and died a year later. Later tradition added to the majesty of her life, and the Fatimid dynasty derived its name from hers.
Fatimid \'fa-to-m3d\ dynasty (909-1171) Isma'Ili ShTite dynasty of North Africa and the Middle East. Its members traced their descent from Fatimah, a daughter of the Prophet Muhammad. As Shfite Muslims, they opposed the Sunnite caliphate of the ‘Abbasid dynasty, which they were determined to supplant. From Yemen they expanded into North Africa and Sicily, and in 909 their imam emerged to proclaim the new dynasty. The
first four Fatimid caliphs ruled from Tunisia, but the conquest of Egypt in 969 occasioned the building of a new capital, Cairo. At its height, the dynasty controlled Mecca and Medina, Syria, Palestine, and Africa’s Red Sea coast. Seeking to overthrow the 'Abbasids, the Fatimids maintained a network of missionaries and agents in 'Abbasid territories (see Assas¬ sin). In 1057-59 the Fatimid caliph was briefly proclaimed in Baghdad, the 'Abbasid capital, but Fatimid fortunes declined thereafter. Attacks by Crusaders, Turks, and Byzantines and factionalism in the armed forces weakened the caliphate; disputes over succession to the title of caliph led to the dynasty’s final end, however, as many of the Asian missionaries broke away, and the central government came to rely on non-lsma'lll troops. The last caliph died in 1171, and the dynasty was succeeded by the Sunnite Ayyubid dynasty.
fatty acid Organic compound that is an important component of lipids in plants, animals, and microorganisms. Fatty acids are carboxylic acids with a long hydrocarbon chain, usually straight, as the fourth substituent group on the carboxyl (—COOH) group (see functional group) that makes the molecule an acid. If the carbon-to-carbon bonds (see bonding) in that chain are all single, the fatty acid is saturated; artificial saturation is called hydrogenation. A fatty acid with one double bond is monounsaturated; one with more is polyunsaturated. These are more reactive chemically. Most unsaturated fats are liquid at room temperature, so food manufacturers hydrogenate them to make them solid (see margarine). A high level of saturated fatty acids in the diet raises blood cholesterol levels. A few fatty acids have branched chains. Others (e.g., prostaglandins) contain ring structures. Fatty acids in nature are always combined, usually with glyc¬ erol as triglycerides in fats. Oleic acid (unsaturated, with 18 carbon atoms) is almost half of human fat and is abundant in such oils as olive, palm, and peanut. Most animals, including mammals, cannot synthesize some unsaturated “essential” fatty acids; humans need linoleic, linolenic, and arachidonic acids in their diet.
Faulhaber \'faul-,ha-b9r\, Michael von (b. March 5, 1869, Heiden- feld, Bavaria—d. June 12, 1952, Munich, W.Ger.) German religious leader and prominent opponent of the Nazis. Ordained in 1892, he was bishop of Speyer before becoming cardinal and Munich’s archbishop. In 1923 he contributed to the failure of Adolf Hitler’s Beer Hall Putsch. Dur¬ ing the Nazi regime he delivered the famous sermons later published as Judaism, Christianity, and Germany (1934), which emphasized the Jew¬ ish background of Christianity and asserted that Christian values were fundamental to German culture. Despite attempts on his life, he vigor¬ ously criticized Nazism in his sermons until the collapse of the Third Reich. After the war he received West Germany’s highest award, the Grand Cross of the Order of Merit.
Faulkner Vfok-norV William (Cuthbert) orig. William Cuth- bert Falkner (b. Sept. 25, 1897, New Albany, Miss., U.S.—d. July 6, 1962, Byhalia, Miss.) U.S. writer. Faulkner dropped out of high school and only briefly attended college. He spent most of his life in Oxford, Miss. He is best known for his cycle of works set in fictional Yoknap- atawpha County, which becomes an emblem of the American South and its tragic history. His first major novel. The Sound and the Fury (1929), was marked by radical technical experimentation, including stream of consciousness. His American reputation, which lagged behind his Euro¬ pean reputation, was boosted by As I Lay Dying (1930), Light in August (1932), Absalom, Absalom! (1936), and Go Down, Moses (1942), which contains the story “The Bear.” The Portable Faulkner (1946) finally brought his work into wide circulation, and he won the Nobel Prize for Literature in 1949. His Collected Stories (1950) won the National Book Award. Both in the U.S. and abroad, especially in Latin America, he was among the most influential writers of the 20th century.
fault In geology, a fracture in the rocks of the Earth’s crust, where com- pressional or tensional forces cause the rocks on the opposite sides of the fracture to be displaced relative to each other. Faults range in length from a few inches to hundreds of miles, and displacement may also range from less than an inch to hundreds of miles along the fracture surface (the fault plane). Most, if not all, earthquakes are caused by rapid movement along faults. Faults are common throughout the world. A well-known example is the San Andreas Fault near the western coast of the U.S. The total movement along this fault during the last few million years appears to have been several miles.
fauna All the species of animals found in a particular region, period, or special environment. Five faunal realms, based on terrestrial animal spe-
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faunal succession ► fayd I 661
cies, are generally recognized: Holarctic, including Nearactic (North America) and Paleartic (Eurasia and northern Africa); Paleotropical (tropi¬ cal Africa and Southeast Asia); Neotropical (Central and South America); Australian; and Antarctic.
faunal succession, law of Observation that taxonomic groups of animals follow each other in time in a predictable manner. Sequences of successive strata and their corresponding fauna have been matched to form a composite picture detailing the history of the Earth, especially from the beginning of the Cambrian Period. Faunal succession is the fundamen¬ tal tool of stratigraphy and is the basis for the geologic time scale. Floral (plant) succession is also an important tool. Climate and conditions throughout the Earth’s history can be studied using the successive groups because living organisms reflect their environment.