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crystal

(Encyclopedia)CE5 Types of crystal crystal, a solid body bounded by natural plane faces that are the external expression of a regular internal arrangement of constituent atoms, molecules, or ions. The formation...

pharming

(Encyclopedia)pharming färˈmĭng [key], the use of genetically altered livestock, such as cows, goats, pigs, and chickens, to produce medically useful products. In pharming, researchers first create hybrid genes ...

orchard grass

(Encyclopedia)orchard grass or cocksfoot, widely distributed perennial grass (Dactylis glomerata) native to Eurasia and N Africa and extensively naturalized in the United States. It is cultivated as a hay grass mor...

dermatitis

(Encyclopedia)dermatitis dûrˌmətīˈtĭs [key], nonspecific irritation of the skin. The causative agent may be a bacterium, fungus, or parasite; it can also be a foreign substance, known as an allergen. Contact ...

pheromones

(Encyclopedia)pheromones, any of a variety of substances, secreted by many animal species, that alter the behavior of individuals of the same species. Sex attractant pheromones, secreted by a male or female to attr...

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...

marcasite

(Encyclopedia)marcasite märˈkəsīt [key] or white iron pyrites, a mineral closely resembling and having the same chemical composition (FeS2) as pyrite. It differs from pyrite in that it is paler in color, become...

tracer

(Encyclopedia)tracer, an identifiable substance used to follow the course of a physical, chemical, or biological process. In chemistry the ideal tracer has the same chemical properties as the molecule it replaces a...

hedge

(Encyclopedia)hedge, ornamental or protective barrier composed of shrubs or small trees growing in close rows. The plants may be allowed to grow naturally or may be trimmed to various heights and shapes (see topiar...

stele

(Encyclopedia)stele stēˈlē [key], slab of stone or terra-cotta, usually oblong, set up in a vertical position, for votive or memorial purposes. Upon the slabs were carved inscriptions accompanied by ornamental d...