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calculus of variations

(Encyclopedia)calculus of variations, branch of mathematics concerned with finding maximum or minimum conditions for a relationship between two or more variables that depends not only on the variables themselves, a...

Caligula

(Encyclopedia)Caligula kəlĭgˈyo͝olə [key], a.d. 12–a.d. 41, Roman emperor (a.d. 37–a.d. 41); son of Germanicus Caesar and Agrippina the Elder. His real name was Caius Caesar Germanicus. As a small child, h...

black fly

(Encyclopedia)black fly, name for any of the flies of the family Simuliidae. The black fly is about 1⁄8 in. (3.2 mm) long and has large eyes, short legs, a stout, humped back, broad gauzy wings, and piercing-suck...

rainmaking

(Encyclopedia)rainmaking, production of rain by artificial means now generally disregarded, though it is probable that rainmaking hastens or increases rainfall from clouds suitable for natural rainfall. Interest in...

root, in mathematics

(Encyclopedia)root, in mathematics, number or quantity r for which an equation f(r)=0 holds true, where f is some function. If f is a polynomial, r is called a root of f; for example, r=3 and r=−4 are roots of th...

scale, in weights and measures

(Encyclopedia)scale, in weights and measures, instruments for determining weight, generally for other than laboratory use. For the principles of operation of all weighing devices, see balance. Platform scales utili...

Sanader, Ivo

(Encyclopedia)Sanader, Ivo ēˈvō sänändârˈ [key], 1953–, Croatian political leader, b. Split. He worked in marketing and publishing until 1991, when he became manager of the Croatian National Theater in Spl...

smart weapon

(Encyclopedia)smart weapon, missile or steerable bomb equipped with a laser, television, or satellite guidance system. Smart weapons, which use guidance systems that rely on external assistance, are distinguished f...

spraying

(Encyclopedia)spraying, horticultural practice of applying fungicides, insecticides, and herbicides, usually in solution, to plants. It may be accomplished by various means, e.g., the watering can, sprinkler attach...

prime minister

(Encyclopedia)prime minister or premier, chief member of the cabinet in a parliamentary system of government. The prime minister is head of the government, in contrast with the head of state, who may be a constitut...