TQC See Total Quality Control TQM See Total Quality Management
tracery In architecture, bars or ribs used decoratively in windows, espe¬ cially the ornamental openwork in Gothic windows. In the earliest phase, two or three narrow, arched windows were placed close together under a single large arch, with the section of wall between the small and large arches pierced by a circular or four-lobed opening. The complexity of this plate tracery increased, reaching a climax in the magnificent windows of Chartres Cathedral. After c. 1220 windows began to be subdivided by mullions, or upright bars, that continued at the head of the window to branch and form the patterns of bar tracery. Elaborate bar tracery soon became one of the most important elements of Gothic architecture and one of its finest achievements, as in the rose windows of the French Rayon- nant style. The bar tracery of the parallel English Decorated style formed netlike patterns based on the circle, arch, trefoil, and quatrefoil. By the late 14th century, the Perpendicular style replaced curvilinear tracery with straight mullions extending to the top of the main arch, connected at intervals by horizontal bars.
trachea \'tra-ke-9\ or windpipe Tube in the throat and upper thoracic cavity through which air passes in respiration. It begins at the larynx and splits just above heart level into the two main bronchi, which enter the lungs. In adults it is about 6 in. (15 cm) long and 1 in. (2.5 cm) in diam¬ eter. Its structure—a membrane strengthened by 16-20 cartilage rings open in the back, with their free ends connected by muscle bands—allows the trachea to stretch and contract in breathing. An inner mucous mem¬ brane has cilia (see cilium) that project inward to trap particles. Muscle fibres over and alongside the trachea contract in response to cold air or irritants in inhaled air; in coughing, the airway narrows to about one-sixth of its normal size to increase the speed and force of exhalation and to dislodge foreign bodies. Such diseases as diphtheria, syphilis, tuberculosis, and typhoid often involve the trachea.
tracheitis \,tra-ke-'I-t3s\ Inflammation and infection of the trachea. Inhaled irritants can injure the tracheal lining and increase the chance of infection (bacterial or viral). Acute infections, usually bacterial, produce fever, fatigue, and swelling of the tracheal lining but generally do no great damage. Chronic infections, promoted by irritants such as heavy smoking and alcohol abuse, cause progressive tissue degeneration and scarring.
tracheophyte See vascular plant
trachyandesite See latite
trachyte \'tra-,klt, 'tra-,k!t\ Light-coloured, very fine-grained igneous rock composed chiefly of alkali feldspar with only minor mafic minerals (biotite, hornblende, or pyroxene). Trachyte is commonly found in volcanic regions; like many volcanic rocks, it shows a streaked or banded struc¬ ture due to flowing of the congealing lava.
track and field or athletics Variety of sport competitions held on a running track and on the adjacent field. It is the oldest form of organized sports, having been a part of the ancient Olympic Games from c. 776 bc to ad 393. Modem events include various sprint and middle- and long¬ distance races, relay races, hurdling, steeplechase, high jump, pole vault, long
JUMP, TRIPLE jump, SHOT put, DISCUS throw, HAMMER THROW, JAVELIN throw, DECATH¬ LON, PENTATHLON, and HEPTATHLON. CROSS-COUNTRY RUNNING, MARATHONS, and speed walking, which are rarely held on a track, are usually considered adjuncts of track-and-field athletics. Events are held indoors and outdoors, and records are kept separately; some events are modified or eliminated for indoor competition.
Tractarian movement See Oxford movement
tractor High-power, low-speed traction vehicle. The two main types are wheeled and continuous-track. Most modem tractors are powered by internal-combustion engines running on gasoline or diesel fuel. Tractors are used in agriculture, construction, and road building, for pulling equip¬ ment such as plows and cultivators, for pushing implements such as bull¬ dozers and diggers, and for operating stationary devices such as saws and winches. The first tractors grew out of the steam engines used on farms in the late 19th century; in 1892 an Iowa blacksmith, John Froehlich, built the first farm vehicle powered by a gasoline engine. The tractor revolu¬ tionized farming, displacing draft animals and many farm workers. By World War I the tractor inspired the tanks built by the British and French.
Tracy, Benjamin F(ranklin) (b. April 26, 1830, near Owego, N.Y., U.S.—d. Aug. 6, 1915, New York, N.Y.) U.S. public official. He served as a county district attorney (1853-59) and, after fighting in the Ameri¬ can Civil War, as U.S. attorney (1866-73). Appointed secretary of the navy (1889-93) by Pres. Benjamin Harrison, he continued the expansion of the navy begun by William C. Whitney, authorizing construction of new battleships and cruisers. His departmental reforms and modernization con¬ tributed to eventual U.S. naval superiority.
Tracy, Spencer (Bonaventure) (b. April 5, 1900, Milwaukee, Wis., U.S.—d. June 10, 1967, Beverly Hills, Calif.) U.S. film actor. He enrolled in the American Academy of Dramatic Arts in New York City in 1922 and was soon earning roles on Broadway. He first starred on Broadway in The Last Mile (1930) and on film in Up the River (1930). Noted for his craggy features and his sincere performances, he became one of the top stars of the 1930s and ’40s, winning Academy Awards in Captains Courageous (1937) and Boys Town (1938)—the first actor to win con¬ secutive Oscars for best actor—and being nominated for seven other roles, including Inherit the Wind (1960) and Judgment at Nuremberg (1961). He had a long relationship with Katharine Hepburn, with whom he cos¬ tarred in nine films, including Woman of the Year (1942), Adam’s Rib (1949), and Guess Who’s Coming to Dinner (1967).
trade, balance of See balance of trade
Trade, Board of Organized market for the exchange of commodity contracts (see commodity exchange). The Toronto Board of Trade, one of the earliest, was incorporated in 1845. The first grain-futures exchange in the U.S. was organized in Chicago in 1848. The Chicago Board of Trade (CBOT) began as a voluntary association of prominent Chicago grain merchants and was chartered by the Illinois legislature in 1859. Initially it sold grain by sample; later it introduced a system of inspection and grading to standardize the market and facilitate trading. By 1858 access to the trading floor was limited to members with seats on the exchange. It became the world’s largest commodity exchange in terms of volume and value of business.
Trade, Board of in full Lords Commissioners of Trade and Plantations Advisory body that supervised American colonial affairs. Established in 1696 to replace the Lords of Trade (1675-96), it examined colonial legislation to ensure maximum benefit to British trade policies. The board nominated colonial governors, recommended laws affecting the colonies to Parliament, and heard complaints from the colonies about its administrators. It lacked executive or legislative powers, but it became the primary colonial policy-making body of the British government. It was abolished in 1782.
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1930 I trade ► Trajan
trade, restraint of See restraint of trade
trade, terms of Relationship between the prices at which a country sells its exports and the prices paid for its imports. If a country’s export prices rise relative to import prices, its terms of trade are said to have moved in a favourable direction, since, in effect, it now receives more imports for each unit of goods exported. The terms of trade, which depend on the world supply of and demand for the goods involved, indicate how the gains from international trade will be distributed among trading coun¬ tries. An abrupt change in a country’s terms of trade (e.g., a drastic fall in the price of its main export) can cause serious problems in its balance OF PAYMENTS. See also COMPARATIVE ADVANTAGE.