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hydrogenation

(Encyclopedia)hydrogenation hīdrôjˈənāˌshən, hīˌdrəjənāˈshən [key], chemical reaction of a substance with molecular hydrogen, usually in the presence of a catalyst. A common hydrogenation is the harde...

cornet

(Encyclopedia)CE5 Cornet cornet, brass wind musical instrument, created in France about 1830 by adding valves to the post horn. It is usually in B flat and is the same size as the B flat trumpet, but has a more...

cylinder

(Encyclopedia)CE5 Cylinder cylinder, in mathematics, surface generated by a line moving parallel to a given fixed line and continually intersecting a given fixed curve called the directrix; each line of the fam...

alanine

(Encyclopedia)CE5 alanine ălˈənēnˌ [key], organic compound, one of the 20 amino acids commonly found in animal proteins. Only the l-stereoisomer participates in the biosynthesis of proteins (see stereochemi...

Entoprocta

(Encyclopedia)CE5 A. Internal anatomy of a single animal in a Pedicellina colony B. Part of a colony of Pedicellina, representative of the phylum Entoprocta Entoprocta ĕnˌtəprŏkˈtə [key], animal phylum co...

pyrimidine

(Encyclopedia)CE5 Pyrimidines found in deoxyribonucleic acid (DNA) pyrimidine pīrĭmˈĭdēnˌ [key], type of organic base found in certain coenzymes and in the nucleic acids of plant and animal tissue. The th...

panpipes

(Encyclopedia)CE5 Panpipes panpipes, Pandean pipes sĭrˈĭngks [key], musical wind instrument, consisting of graduated tubes closed at one end and fastened together. The player holds the instrument vertically...

‘Oumuamua

(Encyclopedia)‘Oumuamua ōmo͞oˈəmo͞oˈə [key], officially 1I/2017 U1 (‘Oumuamua), interstellar object, the first to be discovered in the solar system. Highly variable in brightness, it also is highly and u...

ziggurat

(Encyclopedia)CE5 Ziggurat ziggurat zĭgˈo͝orăt [key], form of temple common to the Sumerians, Babylonians and Assyrians. The earliest examples date from the end of the 3d millenium b.c., the latest from the...

cysteine

(Encyclopedia)CE5 CE5 cysteine sĭsˈtēn [key], organic compound, one of the 20 amino acids commonly found in animal proteins. Only the l-stereoisomer participates in the biosynthesis of mammalian protein...