balancing of a mechanism
111Mechanical fan — Household electric box fan with a propeller style blade A mechanical fan is a machine used to create flow within a fluid, typically a gas such as air. A fan consists of a rotating arrangement of vanes or blades which act on the air. Usually, it… …
112Shotgun — For other uses, see Shotgun (disambiguation). A pump action Remington 870, two semi automatic …
113Stellar evolution — Life cycle of a Sun like star Stellar evolution is the process by which a star undergoes a sequence of radical changes during its lifetime. Depending on the mass of the star, this lifetime ranges from only a few million years (for the most… …
114Perpetual motion — For other uses, see Perpetual motion (disambiguation). Robert Fludd s 1618 water screw perpetual motion machine from a 1660 wood engraving. This device is widely credited as the first recorded attempt to describe such a device in order to produce …
115Electric motor — For other kinds of motors, see motor (disambiguation). For a railroad electric engine, see electric locomotive. Various electric motors. A 9 volt PP3 transistor battery is in the center foreground for size comparison. An electric motor converts… …
116MicroRNA — The stem loop secondary structure of a pre microRNA from Brassica oleracea. A microRNA (abbreviated miRNA) is a short ribonucleic acid (RNA) molecule found in eukaryotic cells. A microRNA molecule has very few nucleotides (an average of 22)… …
117Organic light-emitting diode — Demonstration of a flexible OLED device A green emitting OLED device An …
118Optical tweezers — (originally called single beam gradient force trap ) are scientific instruments that use a highly focused laser beam to provide an attractive or repulsive force (typically on the order of piconewtons), depending on the refractive index mismatch… …
119Human leukocyte antigen — The human leukocyte antigen system (HLA) is the name of the major histocompatibility complex (MHC) in humans. The superlocus contains a large number of genes related to immune system function in humans. This group of genes resides on chromosome 6 …
120Comprehensive Program for Socialist Economic Integration — Main article: History of the Comecon The Comprehensive Program for Socialist Economic Integration was set up in 1971, and laid the guidelines for Comecon activity until 1990. The distinction between market relations and planned relations made in… …
