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Gurley Unit
Gurley Precision Instruments, or GPI, is an ISO-9001 certified U.S. manufacturing company based in Troy, New York. History Gurley Enterprise was established by William Gurley and Lewis E. Gurley in 1845, brothers who were both alumni of Rensselaer Polytechnic Institute. In 1885 Gurley started making Hydrologic equipment and in the early 1900s acquired many new fields including paper testing equipment and thermometers. During World War II Gurley won the Army-Navy ‘E’ Award for their contribution to the war effort. In the 1950s the company started producing optical encoders. During the Cold war era, Gurley manufactured gyroscopes, sextants, star trackers, theodolites, angle dividers, optical positioning systems, and various other precision guidance devices for guided missiles and for space launch vehicles. Teledyne Corporation acquired W. & L. E. Gurley in 1968. In 1993 Gurley was sold again and became Gurley Precision Instruments. The W. & L. E. Gurley Building in Troy wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Privately Held Company
A privately held company (or simply a private company) is a company whose shares and related rights or obligations are not offered for public subscription or publicly negotiated in the respective listed markets, but rather the company's stock is offered, owned, traded, exchanged privately, or Over-the-counter (finance), over-the-counter. In the case of a closed corporation, there are a relatively small number of shareholders or company members. Related terms are closely-held corporation, unquoted company, and unlisted company. Though less visible than their public company, publicly traded counterparts, private companies have major importance in the world's economy. In 2008, the 441 list of largest private non-governmental companies by revenue, largest private companies in the United States accounted for ($1.8 trillion) in revenues and employed 6.2 million people, according to ''Forbes''. In 2005, using a substantially smaller pool size (22.7%) for comparison, the 339 companies on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theodolite
A theodolite () is a precision optical instrument for measuring angles between designated visible points in the horizontal and vertical planes. The traditional use has been for land surveying, but it is also used extensively for building and infrastructure construction, and some specialized applications such as meteorology and rocket launching. It consists of a moveable telescope mounted so it can rotate around horizontal and vertical axes and provide angular readouts. These indicate the orientation of the telescope, and are used to relate the first point sighted through the telescope to subsequent sightings of other points from the same theodolite position. These angles can be measured with accuracies down to microradians or seconds of arc. From these readings a plan can be drawn, or objects can be positioned in accordance with an existing plan. The modern theodolite has evolved into what is known as a total station where angles and distances are measured electronically, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Air Permeability
Textile fibers, threads, yarns and fabrics are measured in a multiplicity of units. * A fiber, a single filament of natural material, such as cotton, linen or wool, or artificial material such as nylon, polyester, metal or mineral fiber, or man-made cellulosic fibre like viscose, Modal, Lyocell or other rayon fiber is measured in terms of linear mass density, the weight of a given length of fiber. Various units are used to refer to the measurement of a fiber, such as: the denier and tex (linear mass density of fibers), super S (fineness of wool fiber), worsted count, woolen count, linen count (wet spun) (or Number English (Ne)), cotton count (or Number English (Ne)), Number metric (Nm) and yield (the reciprocal of denier and tex). * A yarn, a spun agglomeration of fibers used for knitting, weaving or sewing, is measured in terms of cotton count and yarn density. * Thread, usually consisting of multiple yarns plied together producing a long, thin strand used in sewing or weavi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Historic Landmark
A National Historic Landmark (NHL) is a building, district, object, site, or structure that is officially recognized by the United States government for its outstanding historical significance. Only some 2,500 (~3%) of over 90,000 places listed on the country's National Register of Historic Places are recognized as National Historic Landmarks. A National Historic Landmark District may include contributing properties that are buildings, structures, sites or objects, and it may include non-contributing properties. Contributing properties may or may not also be separately listed. Creation of the program Prior to 1935, efforts to preserve cultural heritage of national importance were made by piecemeal efforts of the United States Congress. In 1935, Congress passed the Historic Sites Act, which authorized the Interior Secretary authority to formally record and organize historic properties, and to designate properties as having "national historical significance", and gave the Nation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teledyne Technologies
Teledyne Technologies Incorporated is an American industrial conglomerate. It was founded in 1960, as Teledyne, Inc., by Henry Singleton and George Kozmetsky. From August 1996 to November 1999, Teledyne existed as part of the conglomerate Allegheny Teledyne Incorporated – a combination of the former Teledyne, Inc., and the former Allegheny Ludlum Corporation. On November 29, 1999, three separate entities, Teledyne Technologies, Allegheny Technologies, and Water Pik Technologies, were spun off as free-standing public companies. Allegheny Technologies retained several companies of the former Teledyne, Inc. that fit with Allegheny's core business of steel and exotic metals production. At various times, Teledyne, Inc., had more than 150 companies with interests as varied as insurance, dental appliances, specialty metals, and aerospace electronics, but many of these had been divested prior to the merger with Allegheny. The new Teledyne Technologies was initially composed of 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Space Launch Vehicle
A launch vehicle or carrier rocket is a rocket designed to carry a payload (spacecraft or satellites) from the Earth's surface to outer space. Most launch vehicles operate from a launch pads, supported by a launch control center and systems such as vehicle assembly and fueling. Launch vehicles are engineered with advanced aerodynamics and technologies, which contribute to large operating costs. An orbital launch vehicle must lift its payload at least to the boundary of space, approximately and accelerate it to a horizontal velocity of at least . Suborbital vehicles launch their payloads to lower velocity or are launched at elevation angles greater than horizontal. Practical orbital launch vehicles are multistage rockets which use chemical propellants such as solid fuel, liquid hydrogen, kerosene, liquid oxygen, or Hypergolic propellants. Launch vehicles are classified by their orbital payload capacity, ranging from small-, medium-, heavy- to super-heavy lift. Mass ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guided Missiles
In military terminology, a missile is a guided airborne ranged weapon capable of self-propelled flight usually by a jet engine or rocket motor. Missiles are thus also called guided missiles or guided rockets (when a previously unguided rocket is made guided). Missiles have five system components: targeting, guidance system, flight system, engine and warhead. Missiles come in types adapted for different purposes: surface-to-surface and air-to-surface missiles (ballistic, cruise, anti-ship, anti-submarine, anti-tank, etc.), surface-to-air missiles (and anti-ballistic), air-to-air missiles, and anti-satellite weapons. Airborne explosive devices without propulsion are referred to as shells if fired by an artillery piece and bombs if dropped by an aircraft. Unguided jet- or rocket-propelled weapons are usually described as rocket artillery. Historically, the word ''missile'' referred to any projectile that is thrown, shot or propelled towards a target; this usage is still ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Star Tracker
A star tracker is an optical device that measures the positions of stars using photocells or a camera. As the positions of many stars have been measured by astronomers to a high degree of accuracy, a star tracker on a satellite or spacecraft may be used to determine the orientation (or attitude) of the spacecraft with respect to the stars. In order to do this, the star tracker must obtain an image of the stars, measure their apparent position in the reference frame of the spacecraft, and identify the stars so their position can be compared with their known absolute position from a star catalog. A star tracker may include a processor to identify stars by comparing the pattern of observed stars with the known pattern of stars in the sky. History In the 1950s and early 1960s, star trackers were an important part of early long-range ballistic missiles and cruise missiles, in the era when inertial navigation systems (INS) were not sufficiently accurate for intercontinental ranges. C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Gurley
William Gurley (March 16, 1821 – January 11, 1887) co-founded what is now known as Gurley Precision Instruments with his brother, and served as vice president and, from 1886 to 1887, acting president of Rensselaer Polytechnic Institute. Gurley was born in Troy, New York, March 16, 1821, the son of Ephraim and Clarissa (Sharp) Gurley. He received the best education afforded by the schools in this vicinity, and choosing the profession of a civil engineer, attended the Rensselaer Polytechnic Institute, from which he graduated in 1839. He worked as a surveyor for a few years and then joined the firm of Oscar Hanks, who was a well-known maker of surveying instruments and church bells in Troy. He worked for Hanks for five years. In 1845, Gurley established his own scientific instrument manufacturing business in partnership with James Phelps. Phelps had had his own shop since 1838. They called the business Phelps & Gurley. In 1844, William Gurley's brother Lewis Ephraim Gurley joined ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sextant
A sextant is a doubly reflecting navigation instrument that measures the angular distance between two visible objects. The primary use of a sextant is to measure the angle between an astronomical object and the horizon for the purposes of celestial navigation. The estimation of this angle, the altitude, is known as ''sighting'' or ''shooting'' the object, or ''taking a sight''. The angle, and the time when it was measured, can be used to calculate a position line on a nautical or aeronautical chart—for example, sighting the Sun at noon or Polaris at night (in the Northern Hemisphere) to estimate latitude (with sight reduction). Sighting the height of a landmark can give a measure of ''distance off'' and, held horizontally, a sextant can measure angles between objects for a position on a chart. A sextant can also be used to measure the lunar distance between the moon and another celestial object (such as a star or planet) in order to determine Greenwich Mean Time and hence ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gyroscope
A gyroscope (from Ancient Greek γῦρος ''gŷros'', "round" and σκοπέω ''skopéō'', "to look") is a device used for measuring or maintaining orientation and angular velocity. It is a spinning wheel or disc in which the axis of rotation (spin axis) is free to assume any orientation by itself. When rotating, the orientation of this axis is unaffected by tilting or rotation of the mounting, according to the conservation of angular momentum. Gyroscopes based on other operating principles also exist, such as the microchip-packaged MEMS gyroscopes found in electronic devices (sometimes called gyrometers), solid-state ring lasers, fibre optic gyroscopes, and the extremely sensitive quantum gyroscope. Applications of gyroscopes include inertial navigation systems, such as in the Hubble Space Telescope, or inside the steel hull of a submerged submarine. Due to their precision, gyroscopes are also used in gyrotheodolites to maintain direction in tunnel mining. Gyroscopes ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
