spark
camshaft
cam
mixture in
intake
valve
combusti
chamber
cylinder
block
valve
spring
exhaust
valve
cylinder
head
cooling
water
piston
crankcase
connecting
rod
crankshaft
Cross section showing one cylinder of a four-stroke internal-combustion engine. In the first stroke (shown), a cam (left) compresses a valve spring, opening the intake valve to admit the fuel-air mixture to the cylinder. Both valves then close, the mixture is compressed by the piston, and current is sent to the spark plug. Ignited by the spark plug, the burning mixture forces the piston down, producing power to turn the crankshaft and run the car. Another cam (right) opens the exhaust valve and the burned exhaust gases exit.
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internal medicine Medical specialty dealing with the entire patient rather than a particular organ system, covering diagnosis and medical (rather than surgical) treatment in adults. Its development began in the 17th century with Thomas Sydenham’s concept of disease, but until disease- specific therapies were developed in the 20th century, internists could do little to treat diseases. As more specific treatments became available, medical knowledge increased, and subspecialties in specific organ sys¬ tems were defined, internal medicine became recognized as a specialty.
internal reflection, total See total internal reflection
Internal Revenue Service (IRS) Agency of the U.S. Department of the Treasury charged with administering and enforcing federal tax laws, except those relating to alcohol, tobacco, firearms, and explosives. It issues rulings and regulations to supplement the provisions of the Inter¬ nal Revenue Code; determines, assesses, and collects internal revenue taxes; and determines exempt organization status.
International, Communist See First International, Second Interna¬ tional, Comintern
international agreement Instrument by which nation-states and international organizations regulate matters of concern. They are governed by international law, and their purposes include the development and codification of international law, the creation of international bodies, and the resolution of actual and potential international conflict. The most com¬ prehensive agreement is a treaty; others, including conventions (e.g., the Geneva Conventions), charters (e.g., the UN charter), and pacts (e.g., the Kellogg-Briand Pact), are less formal and rely primarily on goodwill. Agreements may be negotiated between states, between an organization and a state, between organizations, or between any of those and a non¬ governmental ORGANIZATION.
International Atomic Energy Agency (IAEA) International orga¬ nization officially founded in 1957 to promote the peaceful use of nuclear energy. Based in Vienna, its activities include research on the applicabil¬ ity of nuclear energy to medicine, agriculture, water resources, and indus¬ try; provision of technical assistance; development of radiation safeguards; and public relations programs. Following the First Persian Gulf War, IAEA inspectors were called on to certify that Iraq was not manu¬ facturing nuclear weapons. The IAEA and its director general, Mohamed ElBaradei, were awarded the Nobel Prize for Peace in 2005.
International Bank for Economic Cooperation (IBEC) Inter¬ national bank instituted by an agreement signed by Bulgaria, Hungary, East Germany, Mongolia, Poland, Romania, Czechoslovakia, and the Soviet Union in 1963 to facilitate economic cooperation among member countries and promote their development. Cuba and Vietnam joined later. Its functions included making multilateral settlements in transferable rubles, advancing credit to members with temporary trade imbalances, accepting deposits in transferable rubles and in gold and convertible cur¬ rencies, and conducting arbitrage and other financial operations. After the fall of the Soviet Union it became a Russian bank with a new charter.
International Bank for Reconstruction and Development (IBRD) Main component organization of the World Bank. The IBRD lends money to middle-income and creditworthy poorer countries. Most of its funds come from sales of bonds in international capital markets. More than 180 countries are members of the IBRD. Each member’s vot¬ ing power is linked to its capital subscription; the U.S., with some one- sixth of the shares in the IBRD, has veto power over any proposed changes to the bank. See also International Monetary Fund; United Nations Devel¬ opment Programme.
International Brigades Groups of foreign volunteers who fought on the Republican side against the Nationalist forces in the Spanish Civil War (1936-39). So-called because their members initially came from some 50 countries, the International Brigades were recruited, organized, and directed by the Comintern, with headquarters in Paris. The U.S. con¬ tingent called itself the Abraham Lincoln Batallion. Many of the mostly young recruits were commu¬ nists before they became involved in the conflict; more joined the party during the course of the war. The total number of volunteers reached about 60,000. The brigades were for¬ mally withdrawn from Spain late in
International Court of Justice (ICJ) or World Court Principal judicial body of the United Nations, located at The Hague. Its predeces¬ sor organization was the Permanent Court of International Justice, the judicial body of the League of Nations. Its first session was held in 1946. Its jurisdiction is limited to disputes between states willing to accept its authority on matters of international law. Its decisions are binding, but it has no enforcement power; appeals must be made to the UN Security
"The Internationals—United with the Spaniards We Fight the Invader," poster by Parrilla, published by the International Brigades, 1936-37.
COURTESY OF THE ABRAHAM LINCOLN BRIGADE ARCHIVES, BRANDEIS UNIVERSITY LIBRARY
© 2006 Encyclopaedia Britannica, Inc.
International Criminal Court ► International Refugee Organization I 949
Council. Its 15-member body of judges, each of whom serves a nine-year term, is elected by countries party to the court’s founding statute. No two judges may come from the same country. See also European Court of Jus¬ tice.
International Criminal Court (ICC) Permanent judicial body estab¬ lished by the Rome Statute of the International Criminal Court (1998) to prosecute individuals accused of genocide, war crimes, and crimes against humanity. The court commenced operations on July 1, 2002, after the requisite number of countries (60) ratified the Rome Statute (some 140 countries signed the agreement). The ICC was established as a court of last resort to prosecute the most heinous offenses in cases where national courts fail to act. It is headquartered in The Hague. By 2002 China, Rus¬ sia, and the U.S. had declined to participate in the ICC, and the U.S. had campaigned actively to have its citizens exempted from the court’s juris¬ diction.
International Date Line Imaginary line from the North Pole to the South Pole that arbitrarily separates each calendar day from the next. It corresponds along most of its length to the 180th meridian of longitude but deviates to the east through the Bering Strait to avoid dividing Sibe¬ ria and then deviates to the west to include the Aleutian Islands with Alaska. South of the Equator, another eastward deviation allows certain island groups to have the same day as New Zealand. The date line is a consequence of the worldwide use of timekeeping systems arranged so that local noon corresponds approximately to the time at which the Sun crosses the local meridian of longitude. See also standard time.
international exchange See foreign exchange International Harvester Co. See Navistar International Corp.
International Herald Tribune Daily newspaper published in Paris. It has long been the staple source of English-language news for Ameri¬ can expatriates, tourists, and businesspeople in Europe. Its roots are in the Paris Herald (established 1887); a merger in 1924 between its parent, the New York Herald , and the New York Tribune created the New York Herald- Tribune and the Paris Herald Tribune. The Paris edition, which was far¬ ing well at the time of its parent’s demise in 1966, was renamed when it was rescued by a joint venture of the New York Times, the Washington Post, and Whitney Communications. The New York Times Co. and the Washington Post Co. became half-owners of the paper in 1991. The New York Times Co. became the full owner in 2003.