Meany, George (b. Aug. 16, 1894, New York, N.Y., U.S.—d. Jan. 10, 1980, Washington, D.C.) U.S. labour leader. A plumber by trade, he joined the United Association of Plumbers and Steam Fitters in 1915 and rose through the ranks as a union official. He was elected secretary-treasurer of the American Federation of Labor (AFL) in 1939 and became its presi¬ dent in 1952. He led the merger of the AFL and the Congress of Indus¬ trial Organizations (CIO) in 1955, helping reconcile the two federations despite their competitiveness and long-standing differences. Conservative and anticommunist, as president of the AFL-CIO (1955-79) he steered the
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measles ► Mecherino I 1225
U.S. labour movement away from radicalism. Feisty and often dictatorial, he expelled the Teamsters union from the AFL-CIO in 1957, and he lost the United Automobile Workers in 1967 after disputes with Walter Reuther. Meany wielded considerable influence in the Democratic Party through the 1970s.
measles or rubeola V.ru-be-'o-ls, rii-'be-'o-loX Highly contagious viral childhood disease. It initially resembles a severe cold with red eyes and fever; a blotchy rash and higher fever later develop. After recovery, patients have lifelong immunity. Adult patients tend to have more severe cases. Antibiotics now prevent death from secondary infections. Measles itself, for which there is no drug, requires only bed rest, eye protection, and steam for bronchial irritation. A vaccine developed in the 1960s proved not to give permanent immunity and is too heat-sensitive for use in tropical areas. The worldwide incidence of measles continues to rise. Research is currently directed toward development of a more stable vac¬ cine. See also rubella.
measure theory In mathematics, a generalization of the concepts of length and area (see length, area, and volume) to arbitrary sets of points not composed of line segments or rectangles. A measure is any rule for associating a number with a set. The result must be nonnegative and also additive, meaning that the measure of two nonoverlapping sets equals the sum of their individual measures. This is simple enough for sets consist¬ ing of line segments or rectangles, but the measure of sets such as curved regions or intervals with missing points requires more abstract methods, including limits and upper and lower bounds.
measurement Association of numbers with physical quantities and natural phenomena by comparing an unknown quantity with a known quantity of the same kind. Weights and measures are standard quantities with which such comparisons are made. The earliest ones measured mass (weight), volume (liquid or dry measure), length, and area using units mostly based on dimensions of the human body. The cubit, representing the distance from elbow to fingertips, was the most widespread unit of measure in the ancient world. As such units were standardized, more were added, including units of temperature, luminosity, pressure, and electric current. Measurements made by the senses instead of by measurement devices are called estimates (see estimation).
meat Flesh and other edible parts of animals, particularly mammals, used for food. Not only the muscles and fat but also organs such as the liver, kidney, and heart are consumed as meat. Meat is valued as a complete- protein food, containing all the amino acids necessary for the human body. It is digested slowly, largely because of the presence of fats. Worldwide, pork is the most widely consumed meat; beef is second. Mutton and lamb, goat, venison, and rabbit are other common meats. The U.S. produces and consumes about a third of the world’s meat, while much of the world’s population eats little if any meat, though it is generally prized.
Mecca Arabic Al-Makkah V.al-'ma-koV City (pop., 1992: 965,697), western Saudi Arabia. The holiest city of Islam, it was the birthplace of the Prophet Muhammad. It was his home until ad 622, when he was forced to flee to Medina (see also Hijrah); he returned and captured the city in 630. It came under the control of the Egyptian MamlGk dynasty in 1269 and of the Ottoman Empire in 1517. King Ibn Sa'Od occupied it in 1925, and it became part of the Kingdom of Saudi Arabia. It is a religious cen¬ tre to which Muslims must attempt a pilgrimage (see hajj) once during a lifetime; only Muslims may enter Mecca. Services related to pilgrimages are the main economic activity. It is the site of the Haram Mosque, which contains the Ka'bah.
mechanical advantage Force-amplifying effectiveness of a simple machine (lever, wedge, wheel and axle, pulley, or screw). The theoretical mechanical advantage of a system is the ratio of the force that performs the useful work to the force applied, assuming there is no friction in the system. In practice, the actual mechanical advantage will be less than the theoretical value by an amount determined by the amount of friction.
mechanical efficiency See efficiency
mechanical energy Sum of a system’s kinetic energy (KE) and poten¬ tial energy (PE). Mechanical energy is constant in a system that experi¬ ences no dissipative forces such as friction or air resistance. For example, a swinging pendulum that experiences only gravitation has greatest KE and least PE at the lowest point on the path of its swing, where its speed is greatest and its height least. It has least KE and greatest PE at the extremities of its swing, where its speed is zero and its height is greatest.
As it moves, energy is continuously passing back and forth between the two forms. Neglecting friction and air resistance, the pendulum’s mechanical energy is constant.
mechanical engineering Branch of engineering concerned with the design, manufacture, installation, and operation of engines, machines, and manufacturing processes. Mechanical engineering involves application of the principles of dynamics, control, thermodynamics and heat transfer, fluid MECHANICS, STRENGTH OF MATERIALS, MATERIALS SCIENCE, ELECTRONICS, and MATHEMAT¬ ICS. It is concerned with machine tools, motor vehicles, textile machinery, packaging machines, printing machinery, metalworking machines, weld¬ ing, air conditioning, refrigerators, agricultural machinery, and many other machines and processes essential to an industrial economy.
mechanical system Any building service using machines. They include plumbing, elevators, escalators, and heating and air-conditioning systems. The introduction of mechanization in buildings in the early 20th century brought about major adjustments; the new equipment demanded floor space, and the design team began to include electrical and HVAC (heating, ventilating, and air-conditioning) engineers. Heating and cooling changed dramatically. Modern buildings, with their large heat gains, turned central heating into little more than a supplement. Heat removal is a much more serious burden, especially in warm weather. The roofs of high-rises are occupied by cooling towers and mechanical penthouses; entire floors are often dedicated to the containment of blowers, compres¬ sors, water chillers, boilers, pumps, and generators.