array feed point
51Horn antenna — Pyramidal microwave horn antenna, with a bandwidth of 0.8 to 18 GHz. A coaxial cable feedline attaches to the connector visible at top. This type is called a ridged horn; the curving fins visible inside the mouth of the horn increase the antenna… …
52passeriform — /pas euhr euh fawrm , peuh ser euh /, adj. of or pertaining to the order Passeriformes; passerine. [ < NL Passeriformes, equiv. to L passer sparrow + iformes IFORMES] * * * ▪ bird Introduction also called passerine or perching bird any… …
53agriculture, origins of — Introduction the active production of useful plants or animals in ecosystems that have been created by people. Agriculture has often been conceptualized narrowly, in terms of specific combinations of activities and organisms wet rice production… …
54animal learning — ▪ zoology Introduction the alternation of behaviour as a result of individual experience. When an organism can perceive and change its behaviour, it is said to learn. That animals can learn seems to go without saying. The cat that… …
55biblical literature — Introduction four bodies of written works: the Old Testament writings according to the Hebrew canon; intertestamental works, including the Old Testament Apocrypha; the New Testament writings; and the New Testament Apocrypha. The Old… …
56Solar thermal energy — Solar thermal system for water heating in Santorini, Greece …
57Solar inverter — Internal view of a solar inverter. A solar inverter or PV inverter is a critical component in a Photovoltaic system. It performs the conversion of the variable DC output of the Photovoltaic (PV) modules into a utility frequency AC current that… …
58Photovoltaic system — A photovoltaic system is a system which uses solar cells to convert light into electricity. A photovoltaic system consists of multiple components, including cells, mechanical and electrical connections and mountings and means of regulating and/or …
59United Nations — 1. an international organization, with headquarters in New York City, formed to promote international peace, security, and cooperation under the terms of the charter signed by 51 founding countries in San Francisco in 1945. Abbr.: UN Cf. General… …
60Inauguration of Barack Obama — 2009 Presidential Inauguration of Barack Obama Barack Obama takes the oath of office of the President of the United …
