Columbia Encyclopedia

Search results

424 results found

arch

(Encyclopedia)CE5 Arches arch, the spanning of a wall opening by means of separate units (such as bricks or stone blocks) assembled into an upward curve that maintains its shape and stability through the mutual...

hemorrhagic fever

(Encyclopedia)hemorrhagic fever hĕmˌərăjˈĭk [key], any of a group of viral diseases characterized by sudden onset, muscle and joint pain, fever, bleeding, and shock from loss of blood. Bleeding occurs in the ...

hepatitis

(Encyclopedia)hepatitis hĕpˌətīˈtĭs [key], inflammation of the liver. There are many types of hepatitis. Causes include viruses, toxic chemicals, alcohol consumption, parasites and bacteria, and certain drugs...

infection

(Encyclopedia)infection, invasion of plant or animal tissues by microorganisms, i.e., bacteria, viruses, viroids, fungi, rickettsias, and protozoans. The invasion of body tissues by parasitic worms and other higher...

distillation

(Encyclopedia)distillation, process used to separate the substances composing a mixture. It involves a change of state, as of liquid to gas, and subsequent condensation. The process was probably first used in the p...

chlorate

(Encyclopedia)chlorate pərklōrˈāt, –klôrˈ– [key], salts of chloric acid, HClO3, and perchloric acid, HClO4, respectively. Perchlorates are safer to handle than chlorates; they are more stable when expos...

shaman

(Encyclopedia)shaman shäˈmən, shāˈ–, shăˈ– [key], religious practitioner in various, generally small-scale societies who is believed to be able to diagnose, cure, and sometimes cause illness because of a...

radio-frequency identification

(Encyclopedia)radio-frequency identification (RFID), a technology that uses radio waves to transmit data and uniquely identify an animal, person, or thing. An RFID system typically consists of a tag and a reader. T...

Nemertinea

(Encyclopedia)CE5 A. Ribbon worm, representative of the phylum Nemertinea B. Internal anatomy of a ribbon worm Nemertinea nĕmərtĭnˈēə [key], phylum of elongated, often flattened, marine Worms, sometimes c...

superconductivity

(Encyclopedia)superconductivity, abnormally high electrical conductivity of certain substances. The phenomenon was discovered in 1911 by Heike Kamerlingh Onnes, who found that the resistance of mercury dropped sudd...