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Pelton Turbine
The Pelton wheel or Pelton Turbine is an impulse-type water turbine invented by American inventor Lester Allan Pelton in the 1870s. The Pelton wheel extracts energy from the impulse of moving water, as opposed to water's dead weight like the traditional overshot water wheel. Many earlier variations of impulse turbines existed, but they were less efficient than Pelton's design. Water leaving those wheels typically still had high speed, carrying away much of the dynamic energy brought to the wheels. Pelton's paddle geometry was designed so that when the rim ran at half the speed of the water jet, the water left the wheel with very little speed; thus his design extracted almost all of the water's impulse energywhich made for a very efficient turbine. History Figure from Lester Allan Pelton's original October 1880 patent Lester Allan Pelton was born in Vermillion, Ohio in 1829. In 1850, he traveled overland to take part in the California Gold Rush. Pelton worked by selling ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nevada City, California
Nevada City is the county seat of Nevada County, California, United States, northeast of Sacramento, California, Sacramento, southwest of Reno, Nevada, Reno and northeast of San Francisco. The population was 3,152 as of the 2020 United States census, 2020 census. History The settlement was originally a Nisenan village named . European Americans first settled Nevada City in 1849, during the California Gold Rush, as Nevada (Spanish language, Spanish for "snow-covered", a reference to the snow-topped mountains in the area). It was later called Deer Creek Dry Diggins, and Caldwell's Upper Store. The ''Gold Tunnel'' on the north side of Deer Creek (Nevada County, California), Deer Creek was the city's first mine, built in 1850. The first sawmill in Nevada City was built on Deer Creek, just above town, in August 1850, by Lewis & Son, with a water wheel. In 1850–51, Nevada City was the state's most important mining town, and Nevada County the state's leading gold-mining county. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydroelectricity
Hydroelectricity, or hydroelectric power, is Electricity generation, electricity generated from hydropower (water power). Hydropower supplies 15% of the world's electricity, almost 4,210 TWh in 2023, which is more than all other Renewable energy, renewable sources combined and also more than nuclear power. Hydropower can provide large amounts of Low-carbon power, low-carbon electricity on demand, making it a key element for creating secure and clean electricity supply systems. A hydroelectric power station that has a dam and reservoir is a flexible source, since the amount of electricity produced can be increased or decreased in seconds or minutes in response to varying electricity demand. Once a hydroelectric complex is constructed, it produces no direct waste, and almost always emits considerably less greenhouse gas than fossil fuel-powered energy plants. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bearing (mechanical)
A ball bearing A bearing is a machine element that constrains relative motion to only the desired motion and reduces friction between moving parts. The design of the bearing may, for example, provide for free linear movement of the moving part or for free rotation around a fixed axis; or, it may prevent a motion by controlling the vectors of normal forces that bear on the moving parts. Most bearings facilitate the desired motion by minimizing friction. Bearings are classified broadly according to the type of operation, the motions allowed, or the directions of the loads (forces) applied to the parts. The term "bearing" is derived from the verb " to bear"; a bearing being a machine element that allows one part to bear (i.e., to support) another. The simplest bearings are bearing surfaces, cut or formed into a part, with varying degrees of control over the form, size, roughness, and location of the surface. Other bearings are separate devices installed into a machine or mach ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydraulic Head
Hydraulic head or piezometric head is a measurement related to liquid pressure (normalized by specific weight) and the liquid elevation above a vertical datum., 410 pages. See pp. 43–44., 650 pages. See p. 22, eq.3.2a. It is usually measured as an equivalent liquid surface elevation, expressed in units of length, at the entrance (or bottom) of a piezometer. In an aquifer, it can be calculated from the depth to water in a piezometric well (a specialized water well), and given information of the piezometer's elevation and screen depth. Hydraulic head can similarly be measured in a column of water using a standpipe piezometer by measuring the height of the water surface in the tube relative to a common datum. The hydraulic head can be used to determine a ''hydraulic gradient'' between two or more points. Definition In fluid dynamics, the ''head'' at some point in an incompressible (constant density) flow is equal to the height of a static column of fluid whose pressure at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kinetic Energy
In physics, the kinetic energy of an object is the form of energy that it possesses due to its motion. In classical mechanics, the kinetic energy of a non-rotating object of mass ''m'' traveling at a speed ''v'' is \fracmv^2.Resnick, Robert and Halliday, David (1960) ''Physics'', Section 7-5, Wiley International Edition The kinetic energy of an object is equal to the work, or force ( F) in the direction of motion times its displacement ( s), needed to accelerate the object from rest to its given speed. The same amount of work is done by the object when decelerating from its current speed to a state of rest. The SI unit of energy is the joule, while the English unit of energy is the foot-pound. In relativistic mechanics, \fracmv^2 is a good approximation of kinetic energy only when ''v'' is much less than the speed of light. History and etymology The adjective ''kinetic'' has its roots in the Greek word κίνησις ''kinesis'', meaning "motion". The dichoto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Work (physics)
In science, work is the energy transferred to or from an Physical object, object via the application of force along a Displacement (vector), displacement. In its simplest form, for a constant force aligned with the direction of motion, the work equals the Product (mathematics), product of the force strength and the distance traveled. A force is said to do ''positive work'' if it has a component in the direction of the displacement of the point of application. A force does ''negative work'' if it has a component opposite to the direction of the displacement at the point of application of the force. For example, when a ball is held above the ground and then dropped, the work done by the gravitational force on the ball as it falls is positive, and is equal to the weight of the ball (a force) multiplied by the distance to the ground (a displacement). If the ball is thrown upwards, the work done by the gravitational force is negative, and is equal to the weight multiplied by the dis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impulse (physics)
In classical mechanics, impulse (symbolized by or Imp) is the change in momentum of an object. If the initial momentum of an object is , and a subsequent momentum is , the object has received an impulse : \mathbf=\mathbf_2 - \mathbf_1. Momentum is a Vector (physics), vector quantity, so impulse is also a vector quantity: \sum \mathbf \times \Delta t = \Delta \mathbf. Newton’s second law of motion states that the rate of change of momentum of an object is equal to the resultant force acting on the object: \mathbf=\frac, so the impulse delivered by a steady force acting for time is: \mathbf=\mathbf \Delta t. The impulse delivered by a varying force acting from time to is the integral of the force with respect to time: \mathbf= \int_a^b\mathbf \, \mathrmt. The International System of Units, SI unit of impulse is the newton second (N⋅s), and the dimensional analysis, dimensionally equivalent unit of momentum is the kilogram metre per second (kg⋅m/s). The correspond ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thames, New Zealand
Thames () is a town at the southwestern end of the Coromandel Peninsula in New Zealand's North Island. It is located on the Firth of Thames close to the mouth of the Waihou River. The town is the seat of the Thames-Coromandel (district), New Zealand, Thames-Coromandel District Council. The Māori people, Māori iwi are Ngāti Maru (Hauraki), Ngāti Maru, who are descendants of Marutuahu's son Te Ngako. Ngāti Maru is part of the Ngati Marutuahu confederation of tribes or better known as Hauraki Iwi. Thames had an estimated population of 15,000 in 1870, but this declined to 4,500 in 1881, and it has increased modestly since. It is still the biggest town on the Coromandel Peninsula. Until 2016, a historical Oak, oak tree that was planted by Governor George Grey stood on the corner of Grey and Rolleston streets. Demographics Thames covers and had an estimated population of as of with a population density of people per km2. Thames had a population of 7,212 in the 2023 New Zeal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
A & G Price
A&G Price Limited is an engineering firm and locomotive manufacturer in Thames, New Zealand, founded in 1868. History A&G Price was established in 1868 in Princes Street, Onehunga by Alfred Price (engineer), Alfred Price and George Price, two brothers from Stroud, Gloucestershire. They built almost 100 Flax in New Zealand, flax-milling machines in their first year.Book Reviews ''Rails (magazine), Rails'' June 1983 page 22 The brothers also built machinery for gold miners. They moved to the Coromandel Gold Rushes in 1871 setting up premises in Beach Road, Thames and closing the Onehunga works in 1873 after building 10 coaches and 12 trucks there for the Ministry of Works and Development, Public Works Department. The firm's ownership was transferred to a limited liability company in 1907. Ownership A&G Price Limited remained under family management until November 1949 when it was bought by Wellington engineers, William Cable & Company. The two companies then exchanged board memb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
