Entry Type: Thing - Starting with H

Hydroelectric power is the electricity generated by the gravitational force of falling or flowing water through a turbine connected to a power generator. The three major types of hydropower facilities include reservoirs (high dams), in-stream (low dams), and pumped-storage. The most common type is the high dam, which creates significant reservoirs behind the dam (e.g., Hoover Dam). In 1882, the world’s first hydroelectric power station, located in Appleton, Wisconsin, produced 12.5 kilowatts of electrical power. Also in the early 1880s, a similar facility opened in New York City. Since these early facilities, hydroelectric power from the nation’s waterways has proliferated. Hydroelectric development in Arkansas can generally be grouped into three time periods—1924–1930; 1944–1973; and 1988–1999—and under three sponsoring agencies: Arkansas …

Hymenopterans belong to the Phylum Arthropoda, Subphylum Labiata, Superclass Hexapoda, Class Insecta, and Order Hymenoptera. It is a large order of insects with over 150,000 described species comprising the sawflies, woodwasps, ichneumonids, chalcids, wasps, bees, and ants. In addition, there are over 2,000 extinct taxa. The order ranks third in the top five orders of insects in terms of total number of species. Many examples of this order are found in Arkansas, including the invasive fire ant. The Hymenoptera are divided into two suborders: the Symphyta (which have no waist) and the Apocrita (which have a narrow waist). Symphytans include the horntails, sawflies, and parasitic wood wasps. They have an unconstricted junction between the thorax and abdomen and a serrated …