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Hydrostatic Head
When generating hydropower, the head is the distance that a given water source has to fall before the point where power is generated. Ultimately the force responsible for hydropower is gravity, so a hydroelectricity plant with a tall/high head can produce more power than a similar plant with a short/low head. In short, for a given water flow, a larger head will be converted into greater kinetic energy. That energy is then harnessed by a water wheel or water turbine to create usable hydropower. Fabrics Hydrostatic head is also used as a measure of the waterproofing of a fabric, commonly in clothing and equipment used for outdoor recreation. It is measured as a length (typically millimetres), representing the maximum height of a vertical column of water that could be placed on top of the fabric before water started seeping through the weave. Thus a fabric with a hydrostatic head rating of mm could hold back a column of water five metres high, but no more. Notes {{reflist Se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydroelectric Dam
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] |
Hydropower
Hydropower (from Ancient Greek -, "water"), also known as water power or water energy, is the use of falling or fast-running water to Electricity generation, produce electricity or to power machines. This is achieved by energy transformation, converting the Potential energy, gravitational potential or kinetic energy of a water source to produce power. Hydropower is a method of sustainable energy production. Hydropower is now used principally for Hydroelectricity, hydroelectric power generation, and is also applied as one half of an energy storage system known as pumped-storage hydroelectricity. Hydropower is an attractive alternative to fossil fuels as it does not directly produce Carbon dioxide in Earth's atmosphere, carbon dioxide or other Air pollution, atmospheric pollutants and it provides a relatively consistent source of power. Nonetheless, it has economic, sociological, and environmental downsides and requires a sufficiently energetic source of water, such as a river or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gravity
In physics, gravity (), also known as gravitation or a gravitational interaction, is a fundamental interaction, a mutual attraction between all massive particles. On Earth, gravity takes a slightly different meaning: the observed force between objects and the Earth. This force is dominated by the combined gravitational interactions of particles but also includes effect of the Earth's rotation. Gravity gives weight to physical objects and is essential to understanding the mechanisms responsible for surface water waves and lunar tides. Gravity also has many important biological functions, helping to guide the growth of plants through the process of gravitropism and influencing the circulation of fluids in multicellular organisms. The gravitational attraction between primordial hydrogen and clumps of dark matter in the early universe caused the hydrogen gas to coalesce, eventually condensing and fusing to form stars. At larger scales this results in galaxies and clust ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydroelectric
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] |
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] |
Water Wheels
A water wheel is a machine for converting the kinetic energy of flowing or falling water into useful forms of power, often in a watermill. A water wheel consists of a large wheel (usually constructed from wood or metal), with numerous blades or buckets attached to the outer rim forming the drive mechanism. Water wheels were still in commercial use well into the 20th century, although they are no longer in common use today. Water wheels are used for milling flour in gristmills, grinding wood into pulp for papermaking, hammering wrought iron, machining, ore crushing and pounding fibre for use in the manufacture of cloth. Some water wheels are fed by water from a mill pond, which is formed when a flowing stream is dammed. A channel for the water flowing to or from a water wheel is called a mill race. The race bringing water from the mill pond to the water wheel is a headrace; the one carrying water after it has left the wheel is commonly referred to as a tailrace. Waterwhee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Turbines
A water turbine is a rotary machine that converts kinetic energy and potential energy of water into mechanical work. Water turbines were developed in the 19th century and were widely used for industrial power prior to electrical grids. Now, they are mostly used for electric power generation. Water turbines are mostly found in dams to generate electric power from water potential energy. History Water wheels have been used for hundreds of years for industrial power. Their main shortcoming is size, which limits the flow rate and head (hydraulic), head that can be harnessed. The migration from water wheels to modern turbines took about one hundred years. Development occurred during the Industrial Revolution, using scientific principles and methods. They also made extensive use of new materials and manufacturing methods developed at the time. Swirl The word turbine was introduced by the French engineer Claude Burdin in the early 19th century and is derived from the Greek w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Outdoor Recreation
Outdoor recreation or outdoor activity refers to recreation done outside, most commonly in natural settings. The activities that encompass outdoor recreation vary depending on the physical environment they are being carried out in. These activities can include fishing, hunting, backpacking (wilderness), backpacking, walking and horseback riding — and can be completed individually or collectively. Outdoor recreation is a broad concept that encompasses a varying range of activities and landscapes. Outdoor recreation is typically pursued for purposes of physical exercise, general wellbeing, and spiritual renewal. While a wide variety of outdoor recreational activities can be classified as sports, they do not all demand that a participant be an athlete. Rather, it is the collectivist idea that is at the fore in outdoor recreation, as outdoor recreation does not necessarily encompass the same degree of competitiveness or rivalry that is embodied in sporting matches or championshi ... [...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] |
Tent
A tent is a shelter consisting of sheets of fabric or other material draped over or attached to a frame of poles or a supporting rope. While smaller tents may be free-standing or attached to the ground, large tents are usually anchored using guy ropes tied to stakes or tent pegs. First used as portable homes by nomads, tents are now more often used for recreational camping and as temporary shelters. Tents range in size from " bivouac" structures, just big enough for one person to sleep in, up to huge circus tents capable of seating thousands of people. Tents for recreational camping fall into two categories. Tents intended to be carried by backpackers are the smallest and lightest type. Small tents may be sufficiently light that they can be carried for long distances on a touring bicycle, a boat, or when backpacking. The second type are larger, heavier tents which are usually carried in a car or other vehicle. Depending on tent size and the experience of the person or peop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Waterproofing
Waterproofing is the process of making an object, person or structure waterproof or water-resistant so that it remains relatively unaffected by water or resists the ingress of water under specified conditions. Such items may be used in wet environments or underwater to specified depths. ''Water-resistant'' and ''waterproof'' often refer to resistance to penetration of water in its liquid state and possibly under pressure, whereas ''Damp proofing, damp proof'' refers to resistance to humidity or dampness. Permeation of water vapour through a material or structure is reported as a moisture vapor transmission rate (MVTR). The hulls of boats and ships were once waterproofed by applying tar or pitch (resin), pitch. Modern items may be waterproofed by applying water-repellent coatings or by sealing seams with gaskets or o-rings. Waterproofing is used in reference to building structures (such as basements, decks, or wet areas), watercraft, canvas, clothing (raincoats or waders (foot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
