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Cremona

(Encyclopedia)Cremona krĭmōˈnə, Ital. krāmôˈnä [key], city, capital of Cremona prov., Lomba...

Trent , city, Italy

(Encyclopedia)Trent, Ital. Trento, Latin Tridentum, city (1991 pop. 101,545), capital of Trentino–Alto Adige and of Trent prov., N Italy, on the Adige River and on the road to the Brenner Pass. It is an industria...

Poznań

(Encyclopedia)Poznań pōˈzən [key], city (1994 est. pop. 589,300), capital of Weilkopolskie prov., W central Poland, port on the Warta River. It is an important industrial and railway center and is the site of a...

allotropy

(Encyclopedia)allotropy əlŏˈtrəpē [key] [Gr.,=other form]. A chemical element is said to exhibit allotropy when it occurs in two or more forms in the same physical state; the forms are called allotropes. Allot...

Hall effect

(Encyclopedia)Hall effect, experiment that shows the sign of the charge carriers in a conductor. In 1879 E. H. Hall discovered that when he placed a metal strip carrying a current in a magnetic field, a voltage dif...

phosphoric acid

(Encyclopedia)phosphoric acid, any one of three chemical compounds made up of phosphorus, oxygen, and hydrogen (see acids and bases). The most common, orthophosphoric acid, H3PO4, is usually simply called phosphori...

welding

(Encyclopedia)welding, process for joining separate pieces of metal in a continuous metallic bond. Cold-pressure welding is accomplished by the application of high pressure at room temperature; forge welding (forgi...

Columbia University

(Encyclopedia)Columbia University, mainly in New York City; founded 1754 as King's College by grant of King George II; first college in New York City, fifth oldest in the United States; one of the eight Ivy League ...

bacteria

(Encyclopedia)bacteria [pl. of bacterium], microscopic unicellular prokaryotic organisms characterized by the lack of a membrane-bound nucleus and membrane-bound organelles. Once considered a part of the plant king...

conduction

(Encyclopedia)conduction, transfer of heat or electricity through a substance, resulting from a difference in temperature between different parts of the substance, in the case of heat, or from a difference in elect...