1.
Earthworks (engineering)
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Earthworks are engineering works created through the processing of parts of the earths surface involving quantities of soil or unformed rock. Other common earthworks are land grading to reconfigure the topography of a site, in military engineering, earthworks are, more specifically, types of fortifications constructed from soil. Although soil is not very strong, it is enough that huge quantities can be used. Examples of older earthwork fortifications include moats, sod walls, motte-and-bailey castles, modern examples include trenches and berms. Heavy construction equipment is used due to the amounts of material to be moved — up to millions of cubic metres. In the past, these calculations were done by using a slide rule. Earthworks cost is a function of hauled amount x hauled distance, the goal of mass haul planning is to determine these amounts and the goal of mass haul optimization is to minimize either or both. Now they can be performed with a computer and specialized software, including optimisation on haul cost and not haul distance
2.
Sediment
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For sediment in beverages, see dregs. For example, sand and silt can be carried in suspension in water and on reaching the sea be deposited by sedimentation. Sediments are most often transported by water, but also wind, beach sands and river channel deposits are examples of fluvial transport and deposition, though sediment also often settles out of slow-moving or standing water in lakes and oceans. Desert sand dunes and loess are examples of transport and deposition. Glacial moraine deposits and till are ice-transported sediments, sediment can be classified based on its grain size and/or its composition. Sediment size is measured on a log base 2 scale, called the Phi scale, composition of sediment can be measured in terms of, parent rock lithology mineral composition chemical make-up. This leads to an ambiguity in which clay can be used as both a size-range and a composition, sediment is transported based on the strength of the flow that carries it and its own size, volume, density, and shape. Stronger flows will increase the lift and drag on the particle, causing it to rise, rivers and streams carry sediment in their flows. This sediment can be in a variety of locations within the flow and these relationships are shown in the following table for the Rouse number, which is a ratio of sediment fall velocity to upwards velocity. If the upwards velocity is less than the settling velocity, but still high enough for the sediment to move, it will move along the bed as bed load by rolling, sliding. If the upwards velocity is higher than the velocity, the sediment will be transported high in the flow as wash load. As there are generally a range of different particle sizes in the flow, sediment motion can create self-organized structures such as ripples, dunes, antidunes on the river or stream bed. These bedforms are often preserved in rocks and can be used to estimate the direction. Overland flow can erode soil particles and transport them downslope, the erosion associated with overland flow may occur through different methods depending on meteorological and flow conditions. If the initial impact of rain droplets dislodges soil, the phenomenon is called rainsplash erosion, if overland flow is directly responsible for sediment entrainment but does not form gullies, it is called sheet erosion. If the flow and the substrate permit channelization, gullies may form, glaciers carry a wide range of sediment sizes, and deposit it in moraines. The overall balance between sediment in transport and sediment being deposited on the bed is given by the Exner equation and this expression states that the rate of increase in bed elevation due to deposition is proportional to the amount of sediment that falls out of the flow. This can be localized, and simply due to obstacles, examples are scour holes behind boulders, where flow accelerates
3.
Coastal erosion
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Coastal erosion is the wearing away of land and the removal of beach or dune sediments by wave action, tidal currents, wave currents, drainage or high winds. The study of erosion and sediment redistribution is called coastal morphodynamics and it may be caused by hydraulic action, abrasion, impact and corrosion. On non-rocky coasts, coastal erosion results in rock formations in areas where the coastline contains rock layers or fracture zones with varying resistance to erosion. Softer areas become eroded much faster than harder ones, which result in landforms such as tunnels, bridges, columns. Over time the coast generally evens out, the softer areas fill up with sediment eroded from hard areas, and rock formations are eroded away. Also abrasion commonly happens in areas where there are strong winds, loose sand, the blowing of millions of sharp sand grains creates a sandblasting effect. This effect helps to erode, smooth and polish rocks, the definition of abrasion is grinding and wearing away of rock surfaces through the mechanical action of other rock or sand particles. A place where erosion of a cliffed coast has occurred is at Wamberal in the Central Coast region of New South Wales where houses built on top of the cliffs began to collapse into the sea. This is due to waves causing erosion of the sedimentary material on which the buildings foundations sit. Dunwich, the capital of the English medieval wool trade, disappeared over the period of a few due to redistribution of sediment by waves. The California coast, which has soft cliffs of sedimentary rock and is heavily populated, devils Slide, Santa Barbara, the coast just north of Ensenada, and Malibu are regularly affected. The Holderness coastline on the east coast of England, just north of the Humber Estuary, is one of the fastest eroding coastline in Europe due to its soft clay cliffs and powerful waves. Groynes and other measures to keep it under control has only accelerated the process further down the coast, because longshore drift starves the beaches of sand. The White Cliffs of Dover have also been affected, fort Ricasoli, a historic 17th century fortress in Malta is being threatened by coastal erosion, as it was built on a fault in the headland which is prone to erosion. A small part of one of the walls has already collapsed since the land under it has eroded. Hydraulic action occurs when striking a cliff face compress air in cracks on the cliff face. This exerts pressure on the rock, and can progressively splinter. Over time, the cracks can grow, sometimes forming a cave, the splinters fall to the sea bed where they are subjected to further wave action
4.
Atoll
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An atoll, sometimes called a coral atoll, is a ring-shaped coral reef including a coral rim that encircles a lagoon partially or completely. There may be coral islands/cays on the rim, the coral of the atoll often sits atop the rim of an extinct seamount or volcano which has eroded or subsided partially beneath the water. The lagoon forms over the crater or caldera while the higher rim remains above water or at shallow depths that permit the coral to grow. For the atoll to persist, continued erosion or subsidence must be at a slow enough to permit reef growth upwards and outwards to replace the lost height. The word atoll comes from the Dhivehi word atholhu, meaning an administrative subdivision, the distribution of atolls around the globe is instructive, most of the worlds atolls are in the Pacific Ocean and Indian Ocean. The Atlantic Ocean has no large groups of atolls, other than eight atolls east of Nicaragua that belong to the Colombian department of San Andres and Providencia in the Caribbean. Reef-building corals will thrive only in tropical and subtropical waters of oceans and seas. The northernmost atoll of the world is Kure Atoll at 28°24 N, the southernmost atolls of the world are Elizabeth Reef at 29°58 S, and nearby Middleton Reef at 29°29 S, in the Tasman Sea, both of which are part of the Coral Sea Islands Territory. The next southerly atoll is Ducie Island in the Pitcairn Islands Group, at this latitude coral reefs would not develop without the warming waters of the Gulf Stream. However, Bermuda is termed a pseudo-atoll because its general form, while there is no atoll directly on the equator, the closest atoll to the Equator is Aranuka of Kiribati, with its southern tip just 12 km north of the equator. In most cases, the area of an atoll is very small in comparison to the total area. Atoll islands are low lying, with their elevations less than 5 meters, measured by total area, Lifou is the largest raised coral atoll of the world, followed by Rennell Island. More sources however list as the largest atoll in the world in terms of land area Kiritimati, the remains of an ancient atoll as a hill in a limestone area is called a reef knoll. The second largest atoll by dry land area is Aldabra with 155 km², the largest atoll in terms of island numbers is Huvadhu Atoll in the south of the Maldives with 255 islands. In 1842, Charles Darwin explained the creation of coral atolls in the southern Pacific Ocean based upon observations made during a voyage aboard the HMS Beagle from 1831 to 1836. In time, subsidence carries the old volcano below the ocean surface, at this point, the island has become an atoll. Atolls are the product of the growth of marine organisms. Volcanic islands located beyond the water temperature requirements of hermatypic organisms become seamounts as they subside and are eroded away at the surface
5.
Leonardo da Vinci
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He has been variously called the father of palaeontology, ichnology, and architecture, and is widely considered one of the greatest painters of all time. Sometimes credited with the inventions of the parachute, helicopter and tank, many historians and scholars regard Leonardo as the prime exemplar of the Universal Genius or Renaissance Man, an individual of unquenchable curiosity and feverishly inventive imagination. Much of his working life was spent in the service of Ludovico il Moro in Milan. He later worked in Rome, Bologna and Venice, and he spent his last years in France at the home awarded to him by Francis I of France, Leonardo was, and is, renowned primarily as a painter. Among his works, the Mona Lisa is the most famous and most parodied portrait, Leonardos drawing of the Vitruvian Man is also regarded as a cultural icon, being reproduced on items as varied as the euro coin, textbooks, and T-shirts. Perhaps fifteen of his paintings have survived, Leonardo is revered for his technological ingenuity. He conceptualised flying machines, a type of armoured fighting vehicle, concentrated power, an adding machine. Some of his inventions, however, such as an automated bobbin winder. A number of Leonardos most practical inventions are nowadays displayed as working models at the Museum of Vinci. He made substantial discoveries in anatomy, civil engineering, geology, optics, and hydrodynamics, today, Leonardo is widely considered one of the most diversely talented individuals ever to have lived. Leonardo was born on 15 April 1452 at the hour of the night in the Tuscan hill town of Vinci. He was the son of the wealthy Messer Piero Fruosino di Antonio da Vinci, a Florentine legal notary, and Caterina. Leonardo had no surname in the modern sense – da Vinci simply meaning of Vinci, his birth name was Lionardo di ser Piero da Vinci, meaning Leonardo. The inclusion of the title ser indicated that Leonardos father was a gentleman, little is known about Leonardos early life. He spent his first five years in the hamlet of Anchiano in the home of his mother and his father had married a sixteen-year-old girl named Albiera Amadori, who loved Leonardo but died young in 1465 without children. When Leonardo was sixteen, his father married again to twenty-year-old Francesca Lanfredini, pieros legitimate heirs were born from his third wife Margherita di Guglielmo and his fourth and final wife, Lucrezia Cortigiani. Leonardo received an education in Latin, geometry and mathematics. In later life, Leonardo recorded only two childhood incidents, one, which he regarded as an omen, was when a kite dropped from the sky and hovered over his cradle, its tail feathers brushing his face
6.
Waterway
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A waterway is any navigable body of water. A shipping route consists of one or several waterways, Waterways can include rivers, lakes, seas, oceans, and canals. Vessels using waterways vary from small animal-drawn barges to immense ocean tankers and ocean liners, media related to Waterways at Wikimedia Commons Waterscape - Britains official guide to canals, rivers and lakes
7.
Channel (geography)
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In physical geography, a channel is a type of landform consisting of the outline of a path of relatively shallow and narrow body of fluid, most commonly the confine of a river, river delta or strait. The word is cognate to canal, and sometimes shows in this form, most examples of this are fjords in the Pacific Northwest, a notable exception is the Casiquiare canal. All likely share borrowing from Spanish, Portuguese or French, channels can be either natural or human-made. A channel is typically outlined in terms of its bed and banks, Channel initiation refers to the site on a mountain slope where water begins to flow between identifiable banks. This site is referred to as the head and it marks an important boundary between hillslope processes and fluvial processes. The channel head is the most upslope part of a network and is defined by flowing water between defined identifiable banks. A channel head forms as overland flow and/or subsurface flow accumulate to a point where shear stress can overcome resistance of the ground surface. Channel heads are associated with colluvium, hollows and landslides. Overland flow is a factor in channel initiation where saturation overland flow deepens to increase shear stress. Overland flows converge in topographical depressions where channel initiation begins, soil composition, vegetation, precipitation, and topography dictate the amount and rate of overland flow. The composition of a soil determines how quickly saturation occurs and cohesive strength retards the entrainment of material from overland flows, vegetation slows infiltration rates during precipitation events and plant roots anchor soil on hillslopes. Subsurface flow destabilizes soil and resurfaces on hillslopes where channel heads are often formed and this often results in abrupt channel heads and landslides. Natural channels are formed by fluvial process and are found across the Earth and these are mostly formed by flowing water from the hydrological cycle, though can also be formed by other fluids such as flowing lava. Channels also describe the course through a reef, sand bar, bay. One example is the Columbia River, a located in the US states of Washington and Oregon. A stream channel is the confine of a stream consisting of a bed. Stream channels exist in a variety of geometries, Stream channel development is controlled by both water and sediment movement. There is a difference between low gradient streams and high gradient streams, a wide variety of stream channel types can be distinguished
8.
Reservoir
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A reservoir is a storage space for fluids. These fluids may be water, hydrocarbons or gas, a reservoir usually means an enlarged natural or artificial lake, storage pond or impoundment created using a dam or lock to store water. Reservoirs can be created by controlling a stream that drains a body of water. They can also be constructed in river valleys using a dam, alternately, a reservoir can be built by excavating flat ground or constructing retaining walls and levees. Tank reservoirs store liquids or gases in storage tanks that may be elevated, at grade level, tank reservoirs for water are also called cisterns. Underground reservoirs are used to store liquids, principally either water or petroleum, a dam constructed in a valley relies on the natural topography to provide most of the basin of the reservoir. Dams are typically located at a part of a valley downstream of a natural basin. The valley sides act as walls, with the dam located at the narrowest practical point to provide strength. In many reservoir construction projects, people have to be moved and re-housed, construction of a reservoir in a valley will usually need the river to be diverted during part of the build, often through a temporary tunnel or by-pass channel. In hilly regions, reservoirs are constructed by enlarging existing lakes. Sometimes in such reservoirs the new top water level exceeds the height on one or more of the feeder streams such as at Llyn Clywedog in Mid Wales. In such cases additional side dams are required to contain the reservoir, where water is pumped or siphoned from a river of variable quality or quantity, bank-side reservoirs may be built to store the water. Such reservoirs are usually formed partly by excavation and partly by building a complete encircling bund or embankment, the water stored in such reservoirs may stay there for several months, during which time normal biological processes may substantially reduce many contaminants and almost eliminate any turbidity. The use of reservoirs also allows water abstraction to be stopped for some time. Service reservoirs store fully treated potable water close to the point of distribution, many service reservoirs are constructed as water towers, often as elevated structures on concrete pillars where the landscape is relatively flat. Other service reservoirs can be almost entirely underground, especially in hilly or mountainous country. In the United Kingdom, Thames Water has many underground reservoirs, sometimes called cisterns, built in the 1800s. A good example is the Honor Oak Reservoir in London, constructed between 1901 and 1909, when it was completed it was said to be the largest brick built underground reservoir in the world and it is still one of the largest in Europe
9.
Land reclamation
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Land reclamation, usually known as reclamation, and also known as land fill, is the process of creating new land from ocean, riverbeds, or lake beds. The land reclaimed is known as ground or land fill. In a number of jurisdictions, including parts of the United States. In Alberta, Canada, for example, reclamation is defined by the government as The process of reconverting disturbed land to its former or other productive uses. In Oceania it is referred to as land rehabilitation. Land reclamation can be achieved with a number of different methods, the most simple method involves simply filling the area with large amounts of heavy rock and/or cement, then filling with clay and dirt until the desired height is reached. The process is called infilling and the used to fill the space is generically called infill. Draining of submerged wetlands is often used to land for agricultural use. Deep cement mixing is used typically in situations in which the material displaced by either dredging or draining may be contaminated, the creation of new land was for the need of human activities. Notable examples include, Much of the coastlines of Mumbai, India and it took over 150 years to join the original seven islands of Mumbai. Much of the coastlines of Mainland China, Hong Kong, North Korea and it is estimated that nearly 65% of tidal flats around the Yellow Sea have been reclaimed. Inland lowlands in the Yangtze valley, China, including the areas of important cities like Shanghai, Much of the coastline of Karachi, Pakistan. A part of the Hamad International Airport in Qatar, around 36 square kilometres, the entire island of The Pearl-Qatar situated in West Bay, Qatar. The city-state of Singapore, where land is in supply, is also famous for its efforts on land reclamation. The Palm Islands, The World and hotel Burj al-Arab off Dubai in the United Arab Emirates The Yas Island in Abu Dhabi and it is one of the six divisions of Malé City. The Eko Atlantic in Lagos, Nigeria, mexico City, the chinampas are a famous example. Parts of Panama City urban and street development are based on reclaimed land, aeroparque Jorge Newbery, in Buenos Aires, Argentina One of the earliest large scale projects was the Beemster Polder in the Netherlands, realized in 1612 adding 70 square kilometres of land. In Hong Kong the Praya Reclamation Scheme added 20 to 24 hectares of land in 1890 during the phase of construction
10.
Flood
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A flood is an overflow of water that submerges land which is usually dry. The European Union Floods Directive defines a flood as a covering by water of land not normally covered by water, in the sense of flowing water, the word may also be applied to the inflow of the tide. Floods can also occur in rivers when the flow exceeds the capacity of the river channel. Floods often cause damage to homes and businesses if they are in the flood plains of rivers. Some floods develop slowly, while others such as floods, can develop in just a few minutes. Additionally, floods can be local, impacting a neighborhood or community, or very large, the word flood comes from the Old English flod, a word common to Germanic languages. Deluge myths are stories of a great flood sent by a deity or deities to destroy civilization as an act of divine retribution. Floods can happen on flat or low-lying areas when water is supplied by rainfall or snowmelt more rapidly than it can infiltrate or run off. The excess accumulates in place, sometimes to hazardous depths, surface soil can become saturated, which effectively stops infiltration, where the water table is shallow, such as a floodplain, or from intense rain from one or a series of storms. Infiltration also is slow to negligible through frozen ground, rock, concrete, paving, areal flooding begins in flat areas like floodplains and in local depressions not connected to a stream channel, because the velocity of overland flow depends on the surface slope. Endorheic basins may experience flooding during periods when precipitation exceeds evaporation. Floods occur in all types of river and stream channels, from the smallest ephemeral streams in humid zones to normally-dry channels in arid climates to the worlds largest rivers. When overland flow occurs on tilled fields, it can result in a flood where sediments are picked up by run off. Localized flooding may be caused or exacerbated by drainage obstructions such as landslides, ice, debris, slow-rising floods most commonly occur in large rivers with large catchment areas. The increase in flow may be the result of sustained rainfall, rapid snow melt, monsoons, the cause may be localized convective precipitation or sudden release from an upstream impoundment created behind a dam, landslide, or glacier. In one instance, a flood killed eight people enjoying the water on a Sunday afternoon at a popular waterfall in a narrow canyon. Without any observed rainfall, the rate increased from about 50 to 1,500 cubic feet per second in just one minute. Two larger floods occurred at the site within a week
11.
Erosion
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In earth science, erosion is the action of surface processes that remove soil, rock, or dissolved material from one location on the Earths crust, then transport it away to another location. Eroded sediment or solutes may be transported just a few millimetres, the rates at which such processes act control how fast a surface is eroded. Feedbacks are also possible between rates of erosion and the amount of eroded material that is carried by, for example. Processes of erosion that produce sediment or solutes from a place contrast with those of deposition, while erosion is a natural process, human activities have increased by 10-40 times the rate at which erosion is occurring globally. At well-known agriculture sites such as the Appalachian Mountains, intensive farming practices have caused erosion up to 100x the speed of the rate of erosion in the region. Excessive erosion causes both on-site and off-site problems, on-site impacts include decreases in agricultural productivity and ecological collapse, both because of loss of the nutrient-rich upper soil layers. In some cases, the end result is desertification. Off-site effects include sedimentation of waterways and eutrophication of bodies, as well as sediment-related damage to roads. Intensive agriculture, deforestation, roads, anthropogenic climate change and urban sprawl are amongst the most significant human activities in regard to their effect on stimulating erosion, however, there are many prevention and remediation practices that can curtail or limit erosion of vulnerable soils. Rainfall, and the surface runoff which may result from rainfall, produces four types of soil erosion, splash erosion, sheet erosion, rill erosion. Splash erosion is generally seen as the first and least severe stage in the erosion process. In splash erosion, the impact of a falling raindrop creates a crater in the soil. The distance these soil particles travel can be as much as 0.6 m vertically and 1.5 m horizontally on level ground. If the soil is saturated, or if the rate is greater than the rate at which water can infiltrate into the soil. If the runoff has sufficient flow energy, it will transport loosened soil particles down the slope, sheet erosion is the transport of loosened soil particles by overland flow. Rill erosion refers to the development of small, ephemeral concentrated flow paths which function as both sediment source and sediment delivery systems for erosion on hillslopes, generally, where water erosion rates on disturbed upland areas are greatest, rills are active. Flow depths in rills are typically of the order of a few centimetres or less and this means that rills exhibit hydraulic physics very different from water flowing through the deeper, wider channels of streams and rivers. Gully erosion occurs when water accumulates and rapidly flows in narrow channels during or immediately after heavy rains or melting snow
12.
Harbor
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A harbor or harbour, or haven, is a body of water where ships, boats and barges seek shelter from stormy weather, or are stored for future use. Ports are often located in harbors, harbors can be natural or artificial. An artificial harbor can have deliberately constructed breakwaters, sea walls, or jettys, or they can be constructed by dredging, in contrast, a natural harbor is surrounded on several sides by prominences of land. Examples of natural harbors include Sydney Harbour, Australia and Trincomalee Harbour in Sri Lanka, artificial harbors are frequently built for use as ports. The oldest artificial harbor known is the Ancient Egyptian site at Wadi al-Jarf, on the Red Sea coast, the largest artificially created harbor is Jebel Ali in Dubai. The Ancient Carthaginians constructed fortified, artificial harbors called cothons, a natural harbor is a landform where a part of a body of water is protected and deep enough to furnish anchorage. Natural harbors have long been of great strategic naval and economic importance, having a protected harbor reduces or eliminates the need for breakwaters as it will result in calmer waves inside the harbor. For harbors near the North and South Poles, being ice-free is an important advantage, the worlds southmost harbor, located at Antarcticas Winter Quarters Bay, is potentially ice-free, depending on the summertime pack ice conditions. Although the worlds busiest port is a hotly contested title, in 2006 the worlds busiest harbor by cargo tonnage was the Port of Shanghai
13.
Berth (moorings)
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A berth is a designated location in a port or harbour used for mooring vessels when they are not at sea. Berths provide a front which allows safe and secure mooring that can then facilitate the unloading or loading of cargo or people from vessels. Berth is the used in ports and harbors for a designated location where a vessel may be moored. Berths are designated by the management of a facility, vessels are assigned to berths by these authorities. Most berths are alongside a quay or a jetty or a floating dock, berths are either general or specific to the types of vessel that use them. The size of the berths varies from 5–10 m for a boat in a marina to over 400 m for the largest tankers. The general rule of thumb is that the length of a berth should be roughly 10% longer than the longest vessel to be moored at the berth. Open Structure Berth Open berths feature structures supported by piles set slightly off shore from the extent of the land or the farthest extent of fill dirt. The following is a list of berth types based on the method of geometry, Finger piers are often used for small to medium vessels associated with passenger travel. Finger piers can also be used for dangerous cargoes such as military munitions that can not be used with offshore berths because of the weight, in these instances long finger piers allow for far reach far off shore with access for rail or other cargo moving methods on the pier. Offshore Berth Used when cargo handling/storage can be hazardous, often offshore berths are created for berthing of oil and gas vessels. They contain stand alone structures called dolphins which have fenders and bollards located to based on the geometry of the vessels which would call the berth. The following is a list of berth types based on cargo of the ships calling, vessels are loaded using either excavators, conveyor belts, and/or pipelines. Storage facilities for the cargo are often alongside the berth – e. g. silos or stockpiles. Container Berth Used to handle standard intermodal containers, vessels are loaded and unloaded by container cranes, designed specifically for the task. These berths will feature large areas of land for container handling near the berth and will also have significant equipment on dock to facilitate movement of containers on. Alongside the quay there is often a flat area used to store both the imported and exported containers. General Berth Used to handle shipments of general cargo
14.
Bridge
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A bridge is a structure built to span physical obstacles without closing the way underneath such as a body of water, valley, or road, for the purpose of providing passage over the obstacle. There are many different designs that each serve a particular purpose, the Oxford English Dictionary traces the origin of the word bridge to an Old English word brycg, of the same meaning. The word can be traced back to Proto-Indo-European *bʰrēw-. The word for the game of the same name has a different origin. The first bridges made by humans were probably spans of cut wooden logs or planks and eventually stones, using a simple support, some early Americans used trees or bamboo poles to cross small caverns or wells to get from one place to another. Dating to the Greek Bronze Age, it is one of the oldest arch bridges still in existence, several intact arched stone bridges from the Hellenistic era can be found in the Peloponnese. The greatest bridge builders of antiquity were the ancient Romans, the Romans built arch bridges and aqueducts that could stand in conditions that would damage or destroy earlier designs. An example is the Alcántara Bridge, built over the river Tagus, the Romans also used cement, which reduced the variation of strength found in natural stone. One type of cement, called pozzolana, consisted of water, lime, sand, brick and mortar bridges were built after the Roman era, as the technology for cement was lost. In India, the Arthashastra treatise by Kautilya mentions the construction of dams, a Mauryan bridge near Girnar was surveyed by James Princep. The bridge was swept away during a flood, and later repaired by Puspagupta, the use of stronger bridges using plaited bamboo and iron chain was visible in India by about the 4th century. A number of bridges, both for military and commercial purposes, were constructed by the Mughal administration in India and this bridge is also historically significant as it is the worlds oldest open-spandrel stone segmental arch bridge. European segmental arch bridges date back to at least the Alconétar Bridge, rope bridges, a simple type of suspension bridge, were used by the Inca civilization in the Andes mountains of South America, just prior to European colonization in the 16th century. During the 18th century there were innovations in the design of timber bridges by Hans Ulrich Grubenmann, Johannes Grubenmann. The first book on bridge engineering was written by Hubert Gautier in 1716, a major breakthrough in bridge technology came with the erection of the Iron Bridge in Shropshire, England in 1779. It used cast iron for the first time as arches to cross the river Severn, with the Industrial Revolution in the 19th century, truss systems of wrought iron were developed for larger bridges, but iron does not have the tensile strength to support large loads. With the advent of steel, which has a tensile strength, much larger bridges were built. In 1927 welding pioneer Stefan Bryła designed the first welded bridge in the world
15.
Pier
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A pier is a raised structure in a body of water, typically supported by well-spaced piles or pillars. Bridges, buildings, and walkways may all be supported by piers, Piers can range in size and complexity from a simple lightweight wooden structure to major structures extended over 1600 metres. In American English, pier may be synonymous with dock, thus in North America and Australia, where many ports were, until recently, built on the multiple pier model, the term tends to imply a current or former cargo-handling facility. In Europe in contrast, where more often use basins and river-side quays than piers. However, the earliest piers pre-date the Victorian age, Piers can be categorized into different groupings according to the principal purpose. However, there is overlap between these categories. Many piers are floating piers, to ensure that the piers raise and this prevents a situation where lines become overly taut or loose by rising or lowering tides. An overly taut or loose tie-line can damage boats by pulling out of the water or allowing them so much leeway that they bang forcefully against the sides of the pier. Working piers were built for the handling of passengers and cargo onto, working piers themselves fall into two different groups. Longer individual piers are found at ports with large tidal ranges. Such piers provided an alternative to impounded docks where cargo volumes were low, or where specialist bulk cargo was handled. The other form of working pier, often called the pier, was built at ports with smaller tidal ranges. Here the principal advantage was to give a greater available quay length for ships to berth against compared to a linear littoral quayside, typically each pier would carry a single transit shed the length of the pier, with ships berthing bow or stern in to the shore. Some major ports consisted of numbers of such piers lining the foreshore, classic examples being the Hudson River frontage of New York. One example, is in use in Progreso, Yucatán, where a pier extends more than 4 miles into the Gulf of Mexico, making it the longest pier in the world. The Progreso Pier supplies much of the peninsula with transportation for the fishing, many other working piers have been demolished, or remain derelict, but some have been recycled as pleasure piers. The best known example of this is Pier 39 in San Francisco, at Southport and the Tweed River on the Gold Coast in Australia, there are piers that support equipment for a sand bypassing system that maintains the health of sandy beaches and navigation channels. Pleasure piers were first built in Britain during the early 19th century, the earliest structures were Ryde Pier, built in 1813/4, Trinity Chain Pier near Leith, built in 1821, and Brighton Chain Pier, built in 1823
16.
Dock (maritime)
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The exact meaning varies among different variants of the English language. Dock may also refer to a dockyard or shipyard where the loading, unloading, building, the earliest known docks were those discovered in Wadi al-Jarf, an ancient Egyptian harbor dating from 2500 BCE located on the Red Sea coast. Archaeologists also discovered anchors and storage jars near the site, a dock from Lothal in India dates from 2400 BCE and was located away from the main current to avoid deposition of silt. This was the earliest known dock found in the world, equipped to berth and it is speculated that Lothal engineers studied tidal movements, and their effects on brick-built structures, since the walls are of kiln-burnt bricks. The engineers built a structure, with north-south arms of average 21.8 metres. In British English, a dock is an area of water used for loading, unloading, building or repairing ships. Such a dock may be created by building enclosing harbour walls into a natural water space. The level of water in the dock is maintained despite the raising and lowering of the tide and this makes transfer of cargo easier. It works like a lock which controls the level and allows passage of ships. The worlds first enclosed wet dock with lock gates to maintain a constant water level irrespective of tidal conditions was the Howland Great Dock on the River Thames, the dock was merely a haven surrounded by trees, with no unloading facilities. The worlds first commercial enclosed wet dock, with quays and unloading warehouses, was the Old Dock at Liverpool, built in 1715, the dock reduced ship waiting giving quick turn arounds, greatly improving the throughput of cargo. A drydock is another variant, also with dock gates, which can be emptied of water to allow investigation, where the water level is not controlled berths may be, Floating where there is always sufficient water to float the ship. NAABSA where ships settle on the bottom at low tide, ships using NAABSA facilities have to be designed for them. A dockyard consists of one or more docks, usually with other structures, in American English, a dock is technically synonymous with pier or wharf—any human-made structure in the water intended for people to be on. In American English, the term for the area between piers is slip. In the cottage country of Canada and the United States, a dock is a platform built over water. The platform is used for the boarding and offloading of small boats, R. Lothal, a Harappan Port Town. New Delhi, Archaeological Survey of India
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Wharf
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A wharf, quay, staith or staithe is a structure on the shore of a harbor or on the bank of a river or canal where ships may dock to load and unload cargo or passengers. Such a structure includes one or more berths, and may also include piers, warehouses, a wharf commonly comprises a fixed platform, often on pilings. Commercial ports may have warehouses that serve as storage areas. A pier, raised over the rather than within it, is commonly used for cases where the weight or volume of cargos will be low. Smaller and more modern wharves are sometimes built on devices to keep them at the same level as the ship. In some contexts wharf and quay may be used to mean pier, berth, in old ports such as London many old wharves have been converted to residential or office use. Certain early railways in England referred to goods loading points as wharves, the term was carried over from marine usage. The person who was resident in charge of the wharf was referred to as a wharfinger. The word wharf comes from the Old English hwearf, meaning bank or shore, wharfage also refers to a fee charged by ports for the cargo handled there. Originally, werf or werva in Old Dutch simply referred to inhabited ground that was not yet built on and this could explain the name Ministry Wharf located at Saunderton, just outside High Wycombe, which is nowhere near any body of water. In support of this explanation is the fact that places in England with wharf in their names are in areas with a high Dutch influence. In the northeast and east of England the term staith or staithe is also used, both originally referred to staithes in the sense of jetties or wharves. However, the term staith may also be used to only to loading chutes or ramps used for bulk commodities like coal in loading ships. Quay, on the hand, has its origin in the Proto-Celtic language. Before it changed to its current form under influence of the modern French quai, its Middle English spelling was key and this in turn also came from the Old North French cai, both roughly meaning sand bank. The Old French term came from Gaulish caium, ultimately tracing back to the Proto-Celtic *kagio- to encompass, modern cognates include Welsh cae fence, hedge and Cornish ke hedge. Canal basin Dock Port Safeguarded wharf The dictionary definition of wharf at Wiktionary The dictionary definition of quay at Wiktionary
18.
Foundation (engineering)
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A foundation is the element of an architectural structure which connects it to the ground, and transfers loads from the structure to the ground. Foundations are generally considered either shallow or deep, foundation engineering is the application of soil mechanics and rock mechanics in the design of foundation elements of structures. Buildings and structures have a history of being built with wood in contact with the ground. Post in ground construction may technically have no foundation, timber pilings were used on soft or wet ground even below stone or masonry walls. In marine construction and bridge building a crisscross of timbers or steel beams in concrete is called grillage, perhaps the simplest foundation is the padstone, a single stone which both spreads the weight on the ground and raises the timber off the ground. Staddle stones are a type of padstone. Dry stone and stones laid in mortar to build foundations are common in parts of the world. Dry laid stone foundations may have painted with mortar after construction. Sometimes the top, visible course of stone is hewn, quarried stones, besides using mortar, stones can also be put in a gabion. One disadvantage is that if using regular steel rebars, the gabion would last much less long than when using mortar, using weathering steel rebars could reduce this disadvantage somewhat. Rubble trench foundations are a shallow trench filled with rubble or stones and these foundations extend below the frost line and may have a drain pipe which helps groundwater drain away. They are suitable for soils with a capacity of more than 10 tonnes/m², shallow foundations, often called footings, are usually embedded about a metre or so into soil. One common type is the spread footing which consists of strips or pads of concrete which extend below the frost line and transfer the weight from walls and columns to the soil or bedrock. Another common type of foundation is the slab-on-grade foundation where the weight of the building is transferred to the soil through a concrete slab placed at the surface. A deep foundation is used to transfer the load of a structure down through the upper layer of topsoil to the stronger layer of subsoil below. There are different types of deep footings including impact driven piles, drilled shafts, caissons, helical piles, geo-piers, the naming conventions for different types of footings vary between different engineers. Historically, piles were wood, later steel, reinforced concrete, a large number of monopile foundations have been utilized in recent years for economically constructing fixed-bottom offshore wind farms in shallow-water subsea locations. For example, a wind farm off the coast of England went online in 2008 with over 100 turbines
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Soil contamination
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Soil contamination or soil pollution as part of land degradation is caused by the presence of xenobiotic chemicals or other alteration in the natural soil environment. It is typically caused by activity, agricultural chemicals, or improper disposal of waste. The most common chemicals involved are petroleum hydrocarbons, polynuclear aromatic hydrocarbons, solvents, pesticides, lead, Contamination is correlated with the degree of industrialization and intensity of chemical usage. In North America and Western Europe the extent of contaminated land is best known, with many of countries in areas having a legal framework to identify. Developing countries tend to be tightly regulated despite some of them having undergone significant industrialization. Soil pollution can be caused by the following Oil drilling Mining and activities by other heavy industries Accidental spills as may happen during activities, in a wider sense, genetically modified plants can count as a risk factor for soils, because of their potential to affect the soil fauna. Any activity that leads to other forms of soil degradation may indirectly worsen the effects in that soil remediation becomes more tedious. Coal naturally concentrates lead and zinc during its formation, as well as heavy metals to a lesser degree. When the coal is burned, most of these metals become concentrated in the ash, coal ash and slag may contain sufficient lead to qualify as a characteristic hazardous waste, defined in the USA as containing more than 5 mg/l of extractable lead using the TCLP procedure. In addition to lead, coal ash typically contains variable but significant concentrations of polynuclear aromatic hydrocarbons and these PAHs are known human carcinogens and the acceptable concentrations of them in soil are typically around 1 mg/kg. Coal ash and slag can be recognised by the presence of off-white grains in soil, gray heterogeneous soil, or bubbly, treated sewage sludge, known in the industry as biosolids, has become controversial as a fertilizer. As it is the byproduct of sewage treatment, it contains more contaminants such as organisms, pesticides. In the European Union, the Urban Waste Water Treatment Directive allows sewage sludge to be sprayed onto land, the volume is expected to double to 185,000 tons of dry solids in 2005. This has good agricultural properties due to the nitrogen and phosphate content. In 1990/1991, 13% wet weight was sprayed onto 0. 13% of the land, however, this is expected to rise 15 fold by 2005. Advocates say there is a need to control this so that microorganisms do not get into water courses. A pesticide is a substance or mixture of substances used to kill a pest, a pesticide may be a chemical substance, biological agent, antimicrobial, disinfectant or device used against any pest. Although there are benefits to the use of pesticides, there are drawbacks, such as potential toxicity to humans
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Environmental remediation
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Environmental remediation deals with the removal of pollution or contaminants from environmental media such as soil, groundwater, sediment, or surface water. This would mean that once requested by the government or a land remediation authority, immediate action should be taken as this can impact negatively on human health, to help with environmental remediation, one can get environmental remediation services. These services help eliminate radiation sources in order to protect the environment. </ref> In the United States, the most comprehensive set of Preliminary Remediation Goals is from the Environmental Protection Agency Region 9, a set of standards used in Europe exists and is often called the Dutch standards. The European Union is rapidly moving towards Europe-wide standards, although most of the nations in Europe have their own standards at present. Once a site is suspected of being contaminated there is a need to assess the contamination, often the assessment begins with preparation of a Phase I Environmental Site Assessment. The historical use of the site and the used and produced on site will guide the assessment strategy and type of sampling. Often nearby sites owned by the company or which are nearby and have been reclaimed, levelled or filled are also contaminated even where the current land use seems innocuous. For example, a car park may have been levelled by using contaminated waste in the fill, also important is to consider off site contamination of nearby sites often through decades of emissions to soil, groundwater, and air. Ceiling dust, topsoil, surface and groundwater of nearby properties should also be tested, in the US there has been a mechanism for taxing polluting industries to form a Superfund to remediate abandoned sites, or to litigate to force corporations to remediate their contaminated sites. There are several tools for mapping these sites and which allow the user to view additional information, Remediation technologies are many and varied but can generally be categorized into ex-situ and in-situ methods. Ex-situ methods involve excavation of affected soils and subsequent treatment at the surface as well as extraction of contaminated groundwater, in-situ methods seek to treat the contamination without removing the soils or groundwater. Various technologies have developed for remediation of oil-contaminated soil/sediments. Traditional remediation approaches consist of soil excavation and disposal to landfill and groundwater pump, thermal desorption is a technology for soil remediation. During the process a desorber volatilizes the contaminants to separate them from especially soil or sludge, after that the contaminants can either be collected or destroyed in an offgas treatment system. Excavation processes can be as simple as hauling the contaminated soil to a regulated landfill, recent advancements in bioaugmentation and biostimulation of the excavated material have also proven to be able to remediate semi-volatile organic compounds onsite. If the contamination affects a river or bay bottom, then dredging of bay mud or other silty clays containing contaminants may be conducted, recently, ExSitu Chemical oxidation has also been utilized in the remediation of contaminated soil. This process involves the excavation of the area into large bermed areas where they are treated using chemical oxidation methods
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Sewage sludge
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Sewage sludge refers to the residual, semi-solid material that is produced as a by-product during sewage treatment of industrial or municipal wastewater. The term septage is also referring to sludge from wastewater treatment but is connected to simple on-site sanitation systems. When fresh sewage or wastewater enters a primary settling tank, approximately 50% of the solid matter will settle out in an hour. This collection of solids is known as raw sludge or primary solids and is said to be fresh before anaerobic processes become active, the sludge will become putrescent in a short time once anaerobic bacteria take over, and must be removed from the sedimentation tank before this happens. This is accomplished in one of two ways, after digesting for an extended period, the result is called digested sludge and may be disposed of by drying and then landfilling. Biosolids is an often used in conjunction with reuse of sewage sludge after sewage sludge treatment. Biosolids can be defined as organic wastewater solids that can be reused after stabilization processes such as anaerobic digestion, opponents of sewage sludge reuse reject this term as a public relations term. Class A sludge is typically dried and pasteurized, and is known as exceptional quality. Class B includes all sludge not classified as Class A, Class B sludge is typically undigested and is volatile. Both classes of sludge may still contain radioactive or pharmaceutical wastes, the amount of sewage sludge produced is proportional to the amount and concentration of wastewater treated, and it also depends on the type of wastewater treatment process used. It can be expressed as kg dry solids per cubic metre of wastewater treated, the total sludge production from a wastewater treatment process is the sum of sludge from primary settling tanks plus excess sludge from the biological treatment step. For example, primary sedimentation produces about 110–170 kg/ML of so-called primary sludge, the sludge production is expressed as kg of dry solids produced per ML of wastewater treated, one mega litre is 103 m3. United States municipal wastewater treatment plants in 1997 produced about 7.7 million dry tons of sewage sludge, as of 2002, about 60% of all sewage sludge was applied to land as a soil amendment and fertilizer for growing crops. Bacteria in Class A sludge products can actually regrow under certain environmental conditions, Pathogens could easily remain undetected in untreated sewage sludge. Pathogens are not a significant health issue if sewage sludge is properly treated, micro-pollutants can become concentrated in sewage sludge. Each of these disposal options comes with a myriad of potential — and in some cases proven — human health, high levels of sterols and other hormones have been detected, with averages in the range of up to 1,000,000 µg/kg sludge. One of the concerns in the treated sludge is the concentrated metals content. Leaching methods can be used to reduce the content and meet the regulatory limit
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Flood control
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Flood control refers to all methods used to reduce or prevent the detrimental effects of flood waters. Flood relief refers to methods used to reduce the effects of flood waters or high water levels, Flooding can be exacerbated by increased amounts of impervious surface or by other natural hazards such as wildfires, which reduce the supply of vegetation that can absorb rainfall. Periodic floods occur on many rivers, forming a region known as the flood plain. During times of rain, some of the water is retained in ponds or soil, some is absorbed by grass and vegetation, some evaporates, floods occur when ponds, lakes, riverbeds, soil, and vegetation cannot absorb all the water. Water then runs off the land in quantities that cannot be carried within stream channels or retained in ponds, lakes. About 30 percent of all precipitation becomes runoff and that amount might be increased by water from melting snow, River flooding is often caused by heavy rain, sometimes increased by melting snow. A flood that rises rapidly, with little or no warning, is called a flash flood, flash floods usually result from intense rainfall over a relatively small area, or if the area was already saturated from previous precipitation. Even when rainfall is light, the shorelines of lakes. Coastal areas are flooded by unusually high tides, such as spring tides, especially when compounded by high winds. It damages property and endangers the lives of humans and other species, rapid water runoff causes soil erosion and concomitant sediment deposition elsewhere. The spawning grounds for fish and other wildlife habitats can become polluted or completely destroyed, some prolonged high floods can delay traffic in areas which lack elevated roadways. Floods can interfere with drainage and economical use of lands, such as interfering with farming, structural damage can occur in bridge abutments, bank lines, sewer lines, and other structures within floodways. Waterway navigation and hydroelectric power are often impaired, financial losses due to floods are typically millions of dollars each year, with the worst floods in recent U. S. history having cost billions of dollars. There are many effects of flooding on human settlements and economic activities. However, flooding can bring benefits, such as making soil more fertile, periodic flooding was essential to the well-being of ancient communities along the Tigris-Euphrates Rivers, the Nile River, the Indus River, the Ganges and the Yellow River, among others. The viability for hydrologically based renewable sources of energy is higher in flood-prone regions, some methods of flood control have been practiced since ancient times. These methods include planting vegetation to retain water, terracing hillsides to slow flow downhill. Other techniques include the construction of levees, lakes, dams, reservoirs and this is the method used for remote sensing the disasters
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Fishing dredge
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The gear is used to fish for scallops, oysters and other species of clams, crabs, and sea cucumber. The dredge is then winched up into the boat and emptied, dredges are also used in connection with the work of the naturalist in marine biology, notably on the Challenger Expedition. The dredge is usually constructed from a steel frame in the form of a scoop. The frame is covered with chain mesh which is open on the front side, the chain mesh functions as a net. Dredges may or may not have teeth along the bar of the frame. In Europe, early dredges had teeth, called tynes, at the bottom and these teeth raked or ploughed the sand and mud, digging up buried clams. This design was improved by using spring-loaded teeth that reduced bottom snagging, the New Bedford dredge does not have teeth. Dredge nets have a mesh in order to let organisms smaller than the target species through. The net catches the larger organisms, in the case of scallop dredging that includes the scallops predators, such as whelks, starfish, in some cases several dredges are attached to a wheeled rigid axle in groups of three or four. A number of these dredges can be towed from a heavy spreading bar, the length of the bar and number of dredges towed depends on the power of the vessel and the room on the side deck for working the dredges. The number might be three on each side on a small 10-metre boat up to 20 on each side for a 30-metre vessel with 1500 hp. The great weight and strength of the gear can disturb the ground it is towed over, overturning rocks, Scallop dredging tends to result in scallops containing grit, and can damage the seabed if done carelessly. So these days scallop dredging is replaced by scuba diving. Like a better mouse trap, there is still a challenge for inventors to produce a kinder, bottom trawling Gathering scallops Gathering seafood by hand Marine biology dredge Oyster boats Solway Harvester National Research Council Effects of Trawling and Dredging on Seafloor Habitat. Committee on Ecosystem Effects of Fishing, ISBN 0-309-08340-0 Hall-Spencer & Moore PG Scallop dredging has profound, long-term impacts on maerl beds. Photo of scallop dredge drawing of scallop dredge Annual oyster dredging match at West Mersea
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Clam
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Clam is a common name for several kinds of bivalve molluscs. The word is applied only to those that live as infauna. In particular, edible infaunal bivalves are often called clams, clams have two shells of equal size connected by two adductor muscles and have a powerful burrowing foot. Clams in the culinary sense do not live attached to a substrate, in culinary usage, clams are commonly eaten marine bivalves, as in clam digging and the resulting soup, clam chowder. Many edible clams such as palourde clams are oval or triangular, however, razor clams have an elongated parallel-sided shell, some clams have life cycles of only one year, while at least one may be over 500 years old. All clams have two shells or valves joined near a hinge with a flexible ligament, and all are filter feeders. A clams shell consists of two valves, which are connected by a joint and a ligament that can be external or internal. The ligament provides tension to bring the valves apart, while one or two muscles can contract to close the valves. Clams also have kidneys, a heart, a mouth, a stomach, a nervous system, in culinary use, within the eastern coast of the United States, the term clam most often refers to the hard clam Mercenaria mercenaria. It may also refer to a few other common species, such as the soft-shell clam, Mya arenaria. Another species commercially exploited on the Atlantic Coast of the United States is the surf clam Spisula solidissima, scallops are also used for food. Clams can be raw, steamed, boiled, baked or fried. They can also be made into clam chowder or they can be cooked using hot rocks, in Japan, clams are often an ingredient of mixed seafood dishes. They can also be made into hot pot, miso soup or Tsukudani, the more commonly used varieties of clams in Japanese cooking are the Shijimi, the Asari and the Hamaguri. In Italy, clams are often an ingredient of mixed seafood dishes or are eaten together with pasta, the more commonly used varieties of clams in Italian cooking are the Vongola, the Cozza and the Tellina. Clams are eaten more in the regions of India, especially in the Konkan, Kerala, Bengal. In Kerala clams are used to make curries and fried with coconut, in Malabar region it is known as elambakka and in middle kerala it is known as kakka. Clams curry made with coconut is a delicious dish from malabar especially in Telicherry region
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Crab
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Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting tail, usually entirely hidden under the thorax. They live in all the oceans, in fresh water. Many other animals with similar names – such as crabs, king crabs, porcelain crabs, horseshoe crabs. Crabs are generally covered with an exoskeleton, composed primarily of calcium carbonate. Crabs are found in all of the oceans, while many crabs live in fresh water and on land. Crabs vary in size from the pea crab, a few wide, to the Japanese spider crab. About 850 species of crab are freshwater, terrestrial or semi-terrestrial species and they were previously thought to be a monophyletic group, but are now believed to represent at least two distinct lineages, one in the Old World and one in the New World. The earliest unambiguous crab fossils date from the Jurassic, although Carboniferous Imocaris, known only from its carapace, the radiation of crabs in the Cretaceous and afterward may be linked either to the break-up of Gondwana or to the concurrent radiation of bony fish, crabs main predators. Crabs often show marked sexual dimorphism, males often have larger claws, a tendency which is particularly pronounced in the fiddler crabs of the genus Uca. In fiddler crabs, males have one claw which is greatly enlarged, another conspicuous difference is the form of the pleon, in most male crabs, this is narrow and triangular in form, while females have a broader, rounded abdomen. This is because female crabs brood fertilised eggs on their pleopods, crabs attract a mate through chemical, visual, acoustic, or vibratory means. Pheromones are used by most fully aquatic crabs, while terrestrial and semiterrestrial crabs often use visual signals, the vast number of brachyuran crabs have internal fertilisation and mate belly-to-belly. For many aquatic species, mating takes place just after the female has moulted and is still soft, females can store the sperm for a long time before using it to fertilise their eggs. When fertilisation has taken place, the eggs are released onto the abdomen, below the tail flap. In this location, they are protected during embryonic development, females carrying eggs are called berried since the eggs resemble round berries. When development is complete, the releases the newly hatched larvae into the water. The release is timed with the tides. The free-swimming tiny zoea larvae can float and take advantage of water currents and they have a spine, which probably reduces the rate of predation by larger animals
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Oyster
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Oyster is the common name for a number of different families of salt-water bivalve molluscs that live in marine or brackish habitats. In some species the valves are highly calcified, and many are somewhat irregular in shape, many, but not all, oysters are in the superfamily Ostreoidea. Some kinds of oysters are consumed by humans, cooked or raw. Some kinds of oysters are harvested for the pearl produced within the mantle. Windowpane oysters are harvested for their translucent shells, which are used to various kinds of decorative objects. True oysters are members of the family Ostreidae and this family includes the edible oysters, which mainly belong to the genera Ostrea, Crassostrea, Ostreola, and Saccostrea. Examples include the Belon oyster, eastern oyster, Olympia oyster, Pacific oyster, almost all shell-bearing mollusks can secrete pearls, yet most are not very valuable. Pearl oysters are not closely related to oysters, being members of a distinct family. Both cultured pearls and natural pearls can be extracted from pearl oysters, though other molluscs, such as the freshwater mussels, the largest pearl-bearing oyster is the marine Pinctada maxima, which is roughly the size of a dinner plate. Not all individual oysters produce pearls naturally, in fact, in a harvest of two and a half tons of oysters, only three to four oysters produce what commercial buyers consider to be absolute perfect pearls. In nature, pearl oysters produce pearls by covering a minute invasive object with nacre, over the years, the irritating object is covered with enough layers of nacre to become a pearl. The many different types, colours and shapes of pearls depend on the pigment of the nacre. Pearl farmers can culture a pearl by placing a nucleus, usually a piece of polished mussel shell, in three to seven years, the oyster can produce a perfect pearl. These pearls are not as valuable as natural pearls, but look exactly the same, in fact, since the beginning of the 20th century, when several researchers discovered how to produce artificial pearls, the cultured pearl market has far outgrown the natural pearl market. A number of molluscs also have common names that include the word oyster, usually because they either taste like or look somewhat like true oysters. Examples include, Thorny oysters in the genus Spondylus Pilgrim oyster, another term for a scallop, because of its good flavor, it commands high prices. Oysters are filter feeders, drawing water in over their gills through the beating of cilia. Suspended plankton and particles are trapped in the mucus of a gill, and from there are transported to the mouth, where they are eaten, digested, Oysters feed most actively at temperatures above 10 °C
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Gold
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Gold is a chemical element with symbol Au and atomic number 79. In its purest form, it is a bright, slightly yellow, dense, soft, malleable. Chemically, gold is a metal and a group 11 element. It is one of the least reactive chemical elements and is solid under standard conditions, Gold often occurs in free elemental form, as nuggets or grains, in rocks, in veins, and in alluvial deposits. It occurs in a solid solution series with the element silver and also naturally alloyed with copper. Less commonly, it occurs in minerals as gold compounds, often with tellurium, golds atomic number of 79 makes it one of the higher numbered, naturally occurring elements. It is thought to have produced in supernova nucleosynthesis, from the collision of neutron stars. Because the Earth was molten when it was formed, almost all of the present in the early Earth probably sank into the planetary core. Gold is resistant to most acids, though it does dissolve in aqua regia, a mixture of acid and hydrochloric acid. Gold also dissolves in solutions of cyanide, which are used in mining and electroplating. Gold dissolves in mercury, forming amalgam alloys, but this is not a chemical reaction, as a precious metal, gold has been used for coinage, jewelry, and other arts throughout recorded history. A total of 186,700 tonnes of gold is in existence above ground, the world consumption of new gold produced is about 50% in jewelry, 40% in investments, and 10% in industry. Gold is also used in infrared shielding, colored-glass production, gold leafing, certain gold salts are still used as anti-inflammatories in medicine. As of 2014, the worlds largest gold producer by far was China with 450 tonnes, Gold is cognate with similar words in many Germanic languages, deriving via Proto-Germanic *gulþą from Proto-Indo-European *ǵʰelh₃-. The symbol Au is from the Latin, aurum, the Latin word for gold, the Proto-Indo-European ancestor of aurum was *h₂é-h₂us-o-, meaning glow. This word is derived from the root as *h₂éu̯sōs, the ancestor of the Latin word Aurora. This etymological relationship is presumably behind the frequent claim in scientific publications that aurum meant shining dawn, Gold is the most malleable of all metals, a single gram can be beaten into a sheet of 1 square meter, and an avoirdupois ounce into 300 square feet. Gold leaf can be thin enough to become semi-transparent
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Diamond
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Diamond is a metastable allotrope of carbon, where the carbon atoms are arranged in a variation of the face-centered cubic crystal structure called a diamond lattice. Diamond is less stable than graphite, but the rate from diamond to graphite is negligible at standard conditions. Diamond is renowned as a material with superlative physical qualities, most of which originate from the covalent bonding between its atoms. In particular, diamond has the highest hardness and thermal conductivity of any bulk material and those properties determine the major industrial application of diamond in cutting and polishing tools and the scientific applications in diamond knives and diamond anvil cells. Because of its extremely rigid lattice, it can be contaminated by very few types of impurities, such as boron, small amounts of defects or impurities color diamond blue, yellow, brown, green, purple, pink, orange or red. Diamond also has relatively high optical dispersion, most natural diamonds are formed at high temperature and pressure at depths of 140 to 190 kilometers in the Earths mantle. Carbon-containing minerals provide the source, and the growth occurs over periods from 1 billion to 3.3 billion years. Diamonds are brought close to the Earths surface through deep volcanic eruptions by magma, Diamonds can also be produced synthetically in a HPHT method which approximately simulates the conditions in the Earths mantle. An alternative, and completely different growth technique is chemical vapor deposition, several non-diamond materials, which include cubic zirconia and silicon carbide and are often called diamond simulants, resemble diamond in appearance and many properties. Special gemological techniques have developed to distinguish natural diamonds, synthetic diamonds. The word is from the ancient Greek ἀδάμας – adámas unbreakable, the name diamond is derived from the ancient Greek αδάμας, proper, unalterable, unbreakable, untamed, from ἀ-, un- + δαμάω, I overpower, I tame. Diamonds have been known in India for at least 3,000 years, Diamonds have been treasured as gemstones since their use as religious icons in ancient India. Their usage in engraving tools also dates to early human history, later in 1797, the English chemist Smithson Tennant repeated and expanded that experiment. By demonstrating that burning diamond and graphite releases the same amount of gas, the most familiar uses of diamonds today are as gemstones used for adornment, a use which dates back into antiquity, and as industrial abrasives for cutting hard materials. The dispersion of light into spectral colors is the primary gemological characteristic of gem diamonds. In the 20th century, experts in gemology developed methods of grading diamonds, four characteristics, known informally as the four Cs, are now commonly used as the basic descriptors of diamonds, these are carat, cut, color, and clarity. A large, flawless diamond is known as a paragon and these conditions are met in two places on Earth, in the lithospheric mantle below relatively stable continental plates, and at the site of a meteorite strike. The conditions for diamond formation to happen in the mantle occur at considerable depth corresponding to the requirements of temperature and pressure
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Metal detector
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A metal detector is an electronic instrument which detects the presence of metal nearby. Metal detectors are useful for finding metal inclusions hidden within objects and they often consist of a handheld unit with a sensor probe which can be swept over the ground or other objects. If the sensor comes near a piece of metal this is indicated by a tone in earphones. Usually the device gives some indication of distance, the closer the metal is, another common type are stationary walk through metal detectors used for security screening at access points in prisons, courthouses, and airports to detect concealed metal weapons on a persons body. The simplest form of a metal detector consists of a producing a alternating current that passes through a coil producing an alternating magnetic field. If a piece of electrically conductive metal is close to the coil, eddy currents will be induced in the metal, if another coil is used to measure the magnetic field, the change in the magnetic field due to the metallic object can be detected. The first industrial metal detectors were developed in the 1960s and were used extensively for mineral prospecting, uses include detecting land mines, the detection of weapons such as knives and guns, geophysical prospecting, archaeology and treasure hunting. Metal detectors are used to detect foreign bodies in food. Towards the end of the 19th century, many scientists and engineers used their knowledge of electrical theory in an attempt to devise a machine which would pinpoint metal. The use of such a device to find ore-bearing rocks would give an advantage to any miner who employed it. Early machines were crude, used a lot of battery power, in 1874, Parisian inventor Gustave Trouvé developed a hand-held device for locating and extracting metal objects such as bullets from human patients. The modern development of the detector began in the 1920s. Gerhard Fischer had developed a system of radio direction-finding, which was to be used for accurate navigation, the system worked extremely well, but Fischer noticed there were anomalies in areas where the terrain contained ore-bearing rocks. He reasoned that if a radio beam could be distorted by metal, in 1925 he applied for, and was granted, the first patent for a metal detector. Although Gerhard Fischer was the first person granted a patent for a detector, the first to apply was Shirl Herr. His application for a hand-held Hidden-Metal Detector was filed in February 1924, Herr assisted Italian leader Benito Mussolini in recovering items remaining from the Emperor Caligulas galleys at the bottom of Lake Nemi, Italy in August 1929. Herrs invention was used by Admiral Richard Byrds Second Antarctic Expedition in 1933 and it was effective up to a depth of eight feet. These units were still heavy, as they ran on vacuum tubes
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Beach nourishment
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Beach nourishment is typically part of a larger coastal defense scheme. Nourishment is typically a repetitive process, since it does not remove the forces that cause erosion. The first nourishment project in the United States was at Coney Island and it is now a common shore protection measure utilized by public and private entities. Nourishment is one of three commonly accepted methods for protecting shorelines, the structural alternative involves constructing a seawall, revetment, groyne or breakwater. Alternatively, with managed retreat the shoreline is left to erode, while relocating buildings, Nourishment gained popularity because it preserved beach resources and avoided the negative effects of hard structures. Instead, nourishment creates a structure by creating a larger sand reservoir. Beaches can erode both naturally and due to human impacts, erosion is a natural response to storm activity. During storms, sand from the visible beach submerges to form sand bars that protect the beach, submersion is only part of the cycle. During calm weather smaller waves return sand from bars to the beach surface in a process called accretion. Some beaches do not have enough available to coastal processes to respond naturally to storms. When not enough sand is available, the beach cannot recover following storms, many areas of high erosion are due to human activities. Reasons can include, seawalls locking up sand dunes, coastal structures like ports and harbors that prevent longshore transport, dams, continuous, long-term renourishment efforts, especially in cuspate-cape coastlines, can play a role in longshore transport inhibition and downdrift erosion. The proportion of sand in a beach that lies below the waterline critically impacts beach nourishment. Two beaches with the amount of visible sand may be much different below the surface. An eroded beach with substantial submerged sand surrounding it may recover without nourishment, nourishing a beach that has little submerged sand requires understanding of the reason that the submerged sand is missing. The same forces that stripped the submerged sand once are likely to do so again, the amount of submerged sand eroded is typically much greater than the amount of missing sand on shore. Replacing only the sand is insufficient unless the submerged sand is also replaced. Otherwise, the beach is unstable and the sand quickly erodes
31.
Peat
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Peat, also called turf, is an accumulation of partially decayed vegetation or organic matter that is unique to natural areas called peatlands, bogs, mires, moors, or muskegs. The peatland ecosystem is the most efficient carbon sink on the planet because peatland plants capture the CO2 which is released from the peat. Sphagnum moss is one of the most common components in peat, soils that contain mostly peat are known as histosols. Peat forms in wetland conditions, where flooding obstructs flows of oxygen from the atmosphere, Peatlands, particularly bogs, are the most important source of peat. That said, other less common types, including fens, pocosins. Landscapes covered in peat are home to specific kinds of plants including Sphagnum moss, ericaceous shrubs, because organic matter accumulates over thousands of years, peat deposits also provide records of past vegetation and climates stored in plant remains like pollen. This allows humans to reconstruct past environments and study changes in land use. Peat is harvested as an important source of fuel in certain parts of the world, by volume, there are about 4 trillion cubic metres of peat in the world, covering a total of around 2% of the global land area, containing about 8 billion terajoules of energy. Over time, the formation of peat is often the first step in the formation of other fossil fuels such as coal. This is also the commonly used in the peat industry. At 106 g CO2/MJ, the carbon dioxide emission intensity of peat is higher than that of coal and natural gas, lastly, peat fires have been responsible for large public health disasters including the 1997 Southeast Asian haze. Peat forms when plant material does not fully decay in acidic and anaerobic conditions and it is composed mainly of wetland vegetation, principally bog plants including mosses, sedges, and shrubs. As it accumulates, the peat holds water and this slowly creates wetter conditions that allow the area of wetland to expand. Peatland features can include ponds, ridges, and raised bogs, most modern peat bogs formed 12,000 years ago in high latitudes after the glaciers retreated at the end of the last ice age. Peat usually accumulates slowly at the rate of about a millimetre per year, using Carbon-dating, scientists found that Peat in peatlands started forming 360 million years ago based on it currently containing 550 Gt of carbon. Peat material is either fibric, hemic, or sapric, fibric peats are the least decomposed and consist of intact fiber. Hemic peats are partially decomposed and sapric are the most decomposed, Phragmites peat is one composed of reed grass, Phragmites australis, and other grasses. It is denser than other types of peat
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Moorland
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Moorland nowadays generally means uncultivated hill land, but includes low-lying wetlands. It is closely related to heath although experts disagree on precisely what distinguishes the types of vegetation, generally, moor refers to highland, high rainfall zones, whereas heath refers to lowland zones which are more likely to be the result of human activity. Most of the worlds moorlands are very diverse ecosystems, in the extensive moorlands of the tropics biodiversity can be extremely high. Moorland also bears a relationship to tundra, appearing as the tundra retreats, the boundary between tundra and moorland constantly shifts with climate change. Heathland and moorland are the most extensive areas of vegetation in the British Isles. The eastern British moorlands are similar to heaths but are differentiated by having a covering of peat, on western moors the peat layer may be several metres thick. There is uncertainty about how many moors were created by human activity, how much the deforestation was caused by climatic changes and how much by human activity is uncertain. A variety of habitat types are found in different world regions of moorland. The wildlife and vegetation forms often lead to high endemism because of the severe soil, for example, in Englands Exmoor is found the rare horse breed the Exmoor Pony, which has adapted to the harsh conditions of that environment. In Europe, the fauna consists of bird species such as red grouse, hen harrier, merlin, golden plover, curlew, skylark, meadow pipit, whinchat, ring ouzel. Other species dominate in moorlands elsewhere, reptiles are few due to the cooler conditions. In Europe, only the common viper is frequent, though in other regions moorlands are commonly home to dozens of reptile species, amphibians such as frogs are well represented in moorlands. When moorland is overgrazed, woody vegetation is often lost, being replaced by coarse, unpalatable grasses and bracken, some hill sheep breeds, such as Scottish Blackface and the Lonk, thrive on the austere conditions of heather moors. Burning of moorland has been practised for a number of reasons and this is recorded in Britain in the fourteenth century. Uncontrolled burning frequently caused problems, and was forbidden by statute in 1607, with the rise of sheep and grouse management in the nineteenth century it again became common practice. Heather is burnt at about 10 or 12 years old when it will regenerate easily, left longer, the woodier stems will burn more aggressively and will hinder regrowth. Burning of moorland vegetation needs to be carefully controlled as the peat itself can catch fire. In addition, uncontrolled burning of heather can promote alternative bracken, as a result, burning is now a controversial practice, Rackham calls it second-best land management
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Eutrophication
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Eutrophication, or more precisely hypertrophication, is the enrichment of a water body with nutrients, usually with an excess amount of nutrients. This process induces growth of plants and algae and due to the biomass load, one example is the bloom or great increase of phytoplankton in a water body as a response to increased levels of nutrients. Eutrophication is almost always induced by the discharge of phosphate-containing detergents, fertilizers, or sewage, Eutrophication arises from the oversupply of nutrients, which leads to overgrowth of plants and algae. After such organisms die, the degradation of their biomass consumes the oxygen in the water. According to Ullmanns Encyclopedia, the limiting factor for eutrophication is phosphate. Phosphorus is a nutrient for plants to live, and is the limiting factor for plant growth in many freshwater ecosystems. Phosphate adheres tightly to soil, so it is transported by erosion. Once translocated to lakes, the extraction of phosphate into water is slow, the sources of these excess phosphates are phosphates in detergent, industrial/domestic run-offs, and fertilizers. With the phasing out of phosphate-containing detergents in the 1970s, industrial/domestic run-off, cultural Eutrophication is the process that speeds up natural eutrophication because of human activity. Extra nutrients are supplied by treatment plants, golf courses, fertilizers, farms. When algae die, they decompose and the contained in that organic matter are converted into inorganic form by microorganisms. This decomposition process consumes oxygen, which reduces the concentration of dissolved oxygen, the depleted oxygen levels in turn may lead to fish kills and a range of other effects reducing biodiversity. Nutrients may become concentrated in a zone and may only be made available again during autumn turn-over or in conditions of turbulent flow. The water becomes cloudy, typically coloured a shade of green, yellow, brown, Eutrophication also decreases the value of rivers, lakes and aesthetic enjoyment. Health problems can occur where eutrophic conditions interfere with drinking water treatment, human activities can accelerate the rate at which nutrients enter ecosystems. Elevated levels of compounds of nitrogen can increase nitrogen availability. Phosphorus is often regarded as the culprit in cases of eutrophication in lakes subjected to point source pollution from sewage pipes. The concentration of algae and the state of lakes correspond well to phosphorus levels in water
34.
Ore
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An ore is a type of rock that contains sufficient minerals with important elements including metals that can be economically extracted from the rock. The ores are extracted from the earth through mining, they are refined to extract the valuable element. The grade or concentration of an ore mineral, or metal, as well as its form of occurrence, will directly affect the costs associated with mining the ore. The cost of extraction must thus be weighed against the value contained in the rock to determine what ore can be processed. Metal ores are generally oxides, sulfides, silicates, or native metals that are not commonly concentrated in the Earths crust, the ores must be processed to extract the metals of interest from the waste rock and from the ore minerals. Ore bodies are formed by a variety of geological processes, the process of ore formation is called ore genesis. An ore deposit is an accumulation of ore and this is distinct from a mineral resource as defined by the mineral resource classification criteria. An ore deposit is one occurrence of a particular ore type, Ore deposits are classified according to various criteria developed via the study of economic geology, or ore genesis. Stratiform arkose-hosted and shale-hosted copper, typified by the Zambian copperbelt and this identifies, early on, whether further investment in estimation and engineering studies is warranted and identifies key risks and areas for further work. This is because the distribution of ores is unequal and dislocated from locations of peak demand. Other, lesser, commodities do not have international clearing houses and benchmark prices and this generally makes determining the price of ores of this nature opaque and difficult. Such metals include lithium, niobium-tantalum, bismuth, antimony and rare earths, most of these commodities are also dominated by one or two major suppliers with >60% of the worlds reserves. The London Metal Exchange aims to add uranium to its list of metals on warrant, the World Bank reports that China was the top importer of ores and metals in 2005 followed by the USA and Japan. Economic geology Mineral resource classification Ore genesis Petrology Froth Flotation Extractive metallurgy DILL, the “chessboard” classification scheme of mineral deposits, Mineralogy and geology from aluminum to zirconium, Earth-Science Reviews, Volume 100, Issue 1-4, June 2010, Pages 1-420
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Abyssal plain
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An abyssal plain is an underwater plain on the deep ocean floor, usually found at depths between 3,000 metres and 6,000 metres. Lying generally between the foot of a rise and a mid-ocean ridge, abyssal plains cover more than 50% of the Earth’s surface. They are among the flattest, smoothest and least explored regions on Earth, Abyssal plains are key geologic elements of oceanic basins. In addition to elements, active oceanic basins also typically include an oceanic trench. Abyssal plains were not recognized as distinct physiographic features of the sea floor until the late 1940s and, until very recently and they are poorly preserved in the sedimentary record, because they tend to be consumed by the subduction process. The creation of the plain is the end result of spreading of the seafloor. Magma rises from above the asthenosphere and as this material reaches the surface at mid-ocean ridges it forms new oceanic crust. This is constantly pulled sideways by spreading of the seafloor, Abyssal plains result from the blanketing of an originally uneven surface of oceanic crust by fine-grained sediments, mainly clay and silt. Much of this sediment is deposited by turbidity currents that have been channelled from the continental margins along submarine canyons down into deeper water, the remainder of the sediment is composed chiefly of pelagic sediments. Metallic nodules are common in areas of the plains, with varying concentrations of metals, including manganese, iron, nickel, cobalt. These nodules may provide a significant resource for future mining ventures, owing in part to their vast size, abyssal plains are currently believed to be a major reservoir of biodiversity. The abyss also exerts significant influence upon ocean carbon cycling, dissolution of calcium carbonate, the structure and function of abyssal ecosystems are strongly influenced by the rate of flux of food to the seafloor and the composition of the material that settles. Factors such as change, fishing practices, and ocean fertilization are expected to have a substantial effect on patterns of primary production in the euphotic zone. This will undoubtedly impact the flux of material to the abyss in a similar manner and thus have a profound effect on the structure, function. The ocean can be conceptualized as being divided into zones, depending on depth. Photosynthesis in turn requires energy from sunlight to drive the chemical reactions that produce organic carbon, the stratum of the water column nearest the surface of the ocean is referred to as the photic zone. The photic zone can be subdivided into two different vertical regions, the uppermost portion of the photic zone, where there is adequate light to support photosynthesis by phytoplankton and plants, is referred to as the euphotic zone. The lower portion of the zone, where the light intensity is insufficient for photosynthesis, is called the dysphotic zone
36.
Dredge drag head
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A dredge drag head is used by a trailing hopper suction dredger to collect sand from the sea floor. The dredge drag head is a structure that is connected to the dredger by a suction pipe. Supported by the gantries and by using hydraulic winches the dredge drag head and suction pipe are let down onto the sea bottom in order to suck a mixture of water and sand. In order to dredge in waves, the pipe is suspended from special davits. The control of mixture of water and sand is done by a dredge drag head visor. The visor controls the amount of water that enters along with the sand, in some cases this visor is hydraulically controlled. To cut the sea bed, the drag head is equipped with replaceable teeth. The nozzles are placed at the front of the drag head and used to cut the sand at the sea bed vertically. Ship Knowledge - Ship design, construction and operation Dredge Knowledge
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Barge
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A barge is a flat-bottomed boat, built mainly for river and canal transport of heavy goods. Some barges are not self-propelled and must be towed or pushed by towboats, Barge is attested from 1300, from Old French barge, from Vulgar Latin barga. The word originally could refer to any small boat, the modern meaning arose around 1480, bark small ship is attested from 1420, from Old French barque, from Vulgar Latin barca. The more precise meaning three-masted ship arose in the 17th century, both are probably derived from the Latin barica, from Greek, βάρις, translit. Egyptian boat, from Coptic, ⲃⲁⲁⲣⲉ bāri small boat, hieroglyphic Egyptian, by extension, the term embark literally means to board the kind of boat called a barque. The long pole used to maneuver or propel a barge has given rise to the saying I wouldnt touch that with a barge pole. On the British canal system, the barge is used to describe a boat wider than a narrowboat. In the United States, deckhands perform the labor and are supervised by a leadman or the mate, the captain and pilot steer the towboat, which pushes one or more barges held together with rigging, collectively called the tow. The crew live aboard the towboat as it travels along the river system or the intracoastal waterways. These towboats travel between ports and are also called line-haul boats, poles are used on barges to fend off the barge as it nears other vessels or a wharf. These are often called pike poles, barges are used today for low-value bulk items, as the cost of hauling goods by barge is very low. Barges are also used for heavy or bulky items, a typical American barge measures 195 by 35 feet. The most common European barge measures 76.5 by 11.4 metres, as an example, on June 26,2006, a 565-short-ton catalytic cracking unit reactor was shipped by barge from the Tulsa Port of Catoosa in Oklahoma to a refinery in Pascagoula, Mississippi. Extremely large objects are normally shipped in sections and assembled onsite, of the reactors 700-mile journey, only about 40 miles were traveled overland, from the final port to the refinery. Canal barges are made for the particular canal in which they will operate. Many barges, primarily Dutch barges, which were designed for carrying cargo along the canals of Europe, are no longer large enough to compete in this industry with larger newer vessels. Many of these barges have been renovated and are now used as hotel barges carrying holidaymakers along the same canals on which they once carried grain or coal. This holds true today, for areas of the world
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Vistula
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The Vistula is the longest and largest river in Poland, at 1,047 kilometres in length. The drainage basin area of the Vistula is 194,424 km2, the remainder is in Belarus, Ukraine and Slovakia. The Vistula rises at Barania Góra in the south of Poland,1,220 meters above sea level in the Silesian Beskids, where it begins with the White Little Vistula and the Black Little Vistula. It empties into the Vistula Lagoon or directly into the Gdańsk Bay of the Baltic Sea with a delta, the name was first recorded by Pomponius Mela in AD40 and by Pliny in AD77 in his Natural History. Mela names the river Vistula, Pliny uses Vistla, the root of the name Vistula is Indo-European *u̯eis- to ooze, flow slowly and is found in many European rivernames. The diminutive endings -ila, -ula, were used in many Indo-European languages, in writing about the Vistula River and its peoples, Ptolemy uses the Greek spelling Ouistoula. Other ancient sources spell it Istula, ammianus Marcellinus refers to the Bisula, note the absence of the -t-. Jordanes uses Viscla, while the Anglo-Saxon poem Widsith refers to it as the Wistla, the Vistula river basin covers 194,424 square kilometres, its average altitude rising to 270 metres above sea level. In addition, the majority of its basin is located at heights of 100 to 200 m above sea level. The highest point of the basin lies at 2,655 metres. The asymmetry of the basin is 73–27%. The most recent glaciation of the Pleistocene epoch, which ended around 10,000 BC, is called the Vistulian glaciation or Weichselian glaciation in regard to north-central Europe. The river forms a delta called the Żuławy Wiślane around the town of Biała Góra near Sztum, about 50 km from the mouth. In the city of Gdańsk the Head of the Leniwka branch separates again into the Szkarpawa branch, the so-called Dead Wisła divides again into the Przegalinie branch flowing into Gdańsk Bay. Until the 14th century the Vistula was divided into an eastern branch, the Elbląg Vistula, and the smaller western branch. Since 1371 the Vistula of Gdańsk is the main artery. After the flood in 1840 an additional branch formed called the Śmiała Wisła, in 1890 through 1895, additional waterworks were carried out up the Świbna. The history of the River Vistula and her valley spans over 2 million years, the river is connected to the geological period called the Quaternary, in which distinct cooling of the climate took place
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Warsaw
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Warsaw is the capital and largest city of Poland. It stands on the Vistula River in east-central Poland, roughly 260 kilometres from the Baltic Sea and 300 kilometres from the Carpathian Mountains. Its population is estimated at 1.750 million residents within a metropolitan area of 3.101 million residents. The city limits cover 516.9 square kilometres, while the area covers 6,100.43 square kilometres. Once described as Paris of the East, Warsaw was believed to be one of the most beautiful cities in the world until World War II. On 9 November 1939, the city was awarded Polands highest military decoration for heroism, Warsaw is one of Europe’s most dynamic metropolitan cities. In 2012 the Economist Intelligence Unit ranked Warsaw as the 32nd most liveable city in the world, in 2017 the city came 4th in the “Business-friendly” category and 8th in the “Human capital and life style”. It was also ranked as one of the most liveable cities in Central, Warsaw is considered an Alpha– global city, a major international tourist destination and a significant cultural, political and economic hub. The city is a significant centre of research and development, BPO, ITO, the Warsaw Stock Exchange is the largest and most important in Central and Eastern Europe. Frontex, the European Union agency for external security, has its headquarters in Warsaw. Together with Frankfurt, London and Paris, Warsaw is also one of the cities with the highest number of skyscrapers in the European Union, the city is the seat of the Polish Academy of Sciences, Warsaw National Philharmonic Orchestra and the University of Warsaw. The historic city-centre of Warsaw with its picturesque Old Town in 1980 was listed as a UNESCO World Heritage Site, buildings represent examples of nearly every European architectural style and historical period. Warsaw provides many examples of architecture from the gothic, renaissance, baroque, neoclassical and modern periods, furthermore, the city is positioning itself as Europes chic cultural capital with thriving art and club scenes and renowned restaurants. Folk etymology attributes the city name to a fisherman, Wars, according to legend, Sawa was a mermaid living in the Vistula River with whom Wars fell in love. In actuality, Warsz was a 12th/13th-century nobleman who owned a village located at the site of Mariensztat neighbourhood. See also the Vršovci family which had escaped to Poland, the official city name in full is miasto stołeczne Warszawa. A native or resident of Warsaw is known as a Varsovian – in Polish warszawiak, warszawianin, warszawianka, warszawiacy, other names for Warsaw include Varsovia and Varsóvia, Varsovie, Varsavia, Warschau, װאַרשע /Varshe, Варшава /Varšava /Varshava, Varšuva, Varsó. The first fortified settlements on the site of todays Warsaw were located in Bródno, after Jazdów was raided by nearby clans and dukes, a new similar settlement was established on the site of a small fishing village called Warszowa
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Poland
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Poland, officially the Republic of Poland, is a country in Central Europe, situated between the Baltic Sea in the north and two mountain ranges in the south. Bordered by Germany to the west, the Czech Republic and Slovakia to the south, Ukraine and Belarus to the east, the total area of Poland is 312,679 square kilometres, making it the 69th largest country in the world and the 9th largest in Europe. With a population of over 38.5 million people, Poland is the 34th most populous country in the world, the 8th most populous country in Europe, Poland is a unitary state divided into 16 administrative subdivisions, and its capital and largest city is Warsaw. Other metropolises include Kraków, Wrocław, Poznań, Gdańsk and Szczecin, the establishment of a Polish state can be traced back to 966, when Mieszko I, ruler of a territory roughly coextensive with that of present-day Poland, converted to Christianity. The Kingdom of Poland was founded in 1025, and in 1569 it cemented a political association with the Grand Duchy of Lithuania by signing the Union of Lublin. This union formed the Polish–Lithuanian Commonwealth, one of the largest and most populous countries of 16th and 17th century Europe, Poland regained its independence in 1918 at the end of World War I, reconstituting much of its historical territory as the Second Polish Republic. In September 1939, World War II started with the invasion of Poland by Nazi Germany, followed thereafter by invasion by the Soviet Union. More than six million Polish citizens died in the war, after the war, Polands borders were shifted westwards under the terms of the Potsdam Conference. With the backing of the Soviet Union, a communist puppet government was formed, and after a referendum in 1946. During the Revolutions of 1989 Polands Communist government was overthrown and Poland adopted a new constitution establishing itself as a democracy, informally called the Third Polish Republic. Since the early 1990s, when the transition to a primarily market-based economy began, Poland has achieved a high ranking on the Human Development Index. Poland is a country, which was categorised by the World Bank as having a high-income economy. Furthermore, it is visited by approximately 16 million tourists every year, Poland is the eighth largest economy in the European Union and was the 6th fastest growing economy on the continent between 2010 and 2015. According to the Global Peace Index for 2014, Poland is ranked 19th in the list of the safest countries in the world to live in. The origin of the name Poland derives from a West Slavic tribe of Polans that inhabited the Warta River basin of the historic Greater Poland region in the 8th century, the origin of the name Polanie itself derives from the western Slavic word pole. In some foreign languages such as Hungarian, Lithuanian, Persian and Turkish the exonym for Poland is Lechites, historians have postulated that throughout Late Antiquity, many distinct ethnic groups populated the regions of what is now Poland. The most famous archaeological find from the prehistory and protohistory of Poland is the Biskupin fortified settlement, dating from the Lusatian culture of the early Iron Age, the Slavic groups who would form Poland migrated to these areas in the second half of the 5th century AD. With the Baptism of Poland the Polish rulers accepted Christianity and the authority of the Roman Church
41.
Suction excavator
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A suction excavator or vacuum excavator is a construction vehicle that removes materials from a hole on land, or removes heavy debris on land. A suction excavator produces powerful suction through a pipe which is up to 30 centimetres or so in diameter. The suction inlet air speed may be up to 100 metres per second and its construction is somewhat like a vacuum truck but with a wider suction hose and a more powerful suction. The end of the tube may be toothed and this helps to cut earth when used for excavating, but when it is used to suck up loose debris and litter, some types of debris items may snag on the teeth. The earth to be sucked out may be loosened first with a compressed-air lance, excavating with a suction excavator may called vacuum excavation, or hydro excavation if a water jet is used. Vacuum excavation is considered a best practice for safely finding and seeing underground utilities, the RSP GmbH have been making suction excavators and stationary suction units since 1993. Since 2000, RSP developed a new principle, the ESE Series. Since 1998, the MTS Mobile Tiefbau Saugsysteme GmbH is making another type of suction excavator and it is said to have a new designed air flow principle, and thus a considerably improved suction performance. The RSP GmbH produced since 1993 suction superstructures mounted onto two, three and four-axle vehicles, stationary suction units as well as custom-made machines, the RSP GmbH in Germany is the market leader for fan based suction technology. When it is emptying its load out, the tank lid hinges off to the right. Stationary units, RSP also produced stationary units for e. g. in cleaning the canals in Venice and it is in the form of a container. Special vehicles, RSP also offer custom machines for special applications, buried pipe systems do not suffer damage. Output is up to sixteen times of that achieved by conventional excavation, in the ESE 32/7, The suction pipes internal diameter is 25 cm The fan produces a maximum pressure reduction of about 30,000 pascals = about 0.3 atmosphere or 4.5 pounds/square inch. Across a circular suction opening 9.8 inches diameter that would give an air speed of about 400 mph. It can suck up objects up to 25 cm or 9.8 inches across of weight up to 30 kilograms =66 pounds. It is described as able to suck up earth, stones, vegetable waste, sand, mud, water, pebbles, rubble, asbestos, railway-type ballast. 84-inch-wide hose entry would be about half a ton. The MTS suction excavators are said to have a much easier air routing that leads to a more open spoil-hold design, saugmaster is a RSP ESE model, it can suck 8 m3/s of air, and its suction tube is 23 cm wide inside. Pacific Tek was founded in 1993 and went into the valve exerciser, pacific Tek founders have created innovations, such as the Angled Vacuum Excavator Tank and 180° Swivel Mount Valve Operator
42.
Vacuum cleaner
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The dirt is collected by either a dustbag or a cyclone for later disposal. Specialized shop vacuums can be used to suck up both dust and liquids, although vacuum cleaner and the short form vacuum are neutral names, in some countries hoover is used instead as a genericized trademark, and as a verb. The name comes from the Hoover Company, one of the first, the device is also sometimes called a sweeper although the same term also refers to a carpet sweeper, a similar invention. The vacuum cleaner evolved from the carpet sweeper via manual vacuum cleaners, the first manual models, using bellows, were developed in the 1860s, and the first motorized designs appeared at the turn of the 20th century, with the first decade being the boom decade. In 1860 a carpet sweeper was invented by Daniel Hess of West Union, Iowa that gathered dust with a rotating brush, another early model was the Whirlwind, invented in Chicago in 1868 by Ives W. McGaffey. The bulky device worked with a belt driven fan cranked by hand that made it awkward to operate, a similar model was constructed by Melville R. Bissell of Grand Rapids, Michigan in 1876. The company later added portable vacuum cleaners to its line of cleaning tools, the end of the 19th century saw the introduction of powered cleaners, although early types used some variation of blowing air to clean instead of suction. One appeared in 1898 when John S. Thurman of St. Louis, thurmans system, powered by an internal combustion engine, traveled to the customers residence on a horse-drawn wagon as part of a door to door cleaning service. Corrine Dufour of Savannah, Georgia received two patents in 1899 and 1900 for another blown air system that seems to have featured the first use of an electric motor. In 1901 powered vacuum cleaners using suction were invented independently by British engineer Hubert Cecil Booth, Booth also may have coined the word vacuum cleaner. Kenneys was a stationary 4,000 lb. steam engine powered system with pipes and hoses reaching into all parts of the building. The first vacuum-cleaning device to be portable and marketed at the market was built in 1905 by Walter Griffiths. In 1906 James B. Kirby developed his first of many vacuums called the Domestic Cyclone It used water for dirt separation. In 1907 department store janitor James Murray Spangler of Canton, Ohio invented the first portable vacuum cleaner. Crucially, in addition to suction from a fan that blew the dirt and dust into a soap box and one of his wifes pillow cases. Their first vacuum was the 1908 Model O, which sold for $60, subsequent innovations included the beater bar in 1919, disposal filter bags in the 1920s, and an upright vacuum cleaner in 1926. In Continental Europe, the Fisker and Nielsen company in Denmark was the first to sell vacuum cleaners in 1910, the design weighed just 17.5 kg and could be operated by a single person. The Swedish company Electrolux launched the innovative Model V in 1921 that was designed to lie on the floor on two thin metal runners and this innovation, conceived by Electrolux founder Axel Wenner-Gren, became a standard feature on generations of future vacuum cleaners
43.
Jan De Nul
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Its main focus is dredging, which accounts for 85% of the turnover. Other areas include civil engineering and environmental technology, founded in 1938, in Hofstade near Aalst, Belgium, Jan De Nul started as a construction company specialised in civil works and maritime construction. It was only in 1951 that the company entered into the dredging business, at the end of 2012, Jan De Nul had 6000 employees and a yearly turnover of 2 billion euro. It is the largest dredging company in the world, other major dredging companies are Dutch companies Royal Boskalis Westminster and Van Oord, Jan De Nul was voted the most attractive employer of Belgium in 2008 and 2009. This includes the Cristobal Colon, launched in 2008, and the worlds largest dredger with a capacity of 46,000 m³ and it can dredge to a water depth of 155m. Joined by her near-sister ship Leiv Eiriksson in 2010, Jan De Nul has one of the worlds largest, if not the largest, the Takoradi Harbour expansion project in Ghana. In April 2009, the Jan De Nul vessel Pompei was hijacked by Somali pirates en route from Aden to the Seychelles. The ship and its crew of ten were released after 71 days on June 28,2009, after De Nul had paid 2.8 million Euros, according to media reports
44.
Van Oord
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Van Oord is a Dutch contracting company that specializes in dredging and land reclamation. Van Oord has undertaken many projects throughout the world, including land reclamation, dredging, the company has one of the worlds largest dredging fleets. The company was founded by Govert van Oord in 1868, in 1990 it acquired Aannemers Combinatie Zinkwerken and in 2003 it acquired Ballast HAM Dredging. A US sales and support office was opened in Houston Texas in 2010
45.
DEME
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The group is based in Zwijndrecht, Belgium, and has current operations on the five continents. The roots of the date back to the mid 19th century. DEME is committed to the practice of sustainable development, in a survey by temporary employment company Randstad Holding of 12,000 Belgians in early 2010 DEME was proclaimed one of the most attractive employers in Belgium. In the process valuable expertise was built up in throwing up banks, reclaiming polders and this millenary experience is well documented in history. At around 1180, an early canal lock was already in operation at the Belgian city of Damme on the canal from Bruges to the sea. In 1292 dredging works are chronicled in the canals that linked the city of Bruges to the North Sea. In his Divina Commedia the Italian writer Dante Alighieri compared the hard embankment on which he was sitting to the dikes that Flemish craftsmen had built between Bruges and the Dutch border, but the millenary tradition, skills and expertise of dealing with water has remained. The roots of DEME are in the region and the Antwerp area of Belgium. Three companies are at the cradle of DEME, Baggerwerken Decloedt & Zoon, Ackermans & van Haaren, around 1850, the De Cloedt family had a small contracting business in the Belgian city of Bruges which diversified into dredging canals and building coastal defences as from 1875. The company would be incorporated in 1928, and is part of DEME as Baggerwerken Decloedt & Zoon. In 1880 the contractors Nicolaas van Haaren and Hendrik-Willem Ackermans established a winning and dredging business in the Belgian city of Antwerp. It was incorporated on 30 December 1924 and remained the core asset of what is nowadays the Belgian investment company Ackermans & van Haaren, maintenance dredging on the Scheldt river was also carried out by Société Générale de Dragage/Algemene Baggermaatschappij. This company was established on 5 April 1930 with the De Cloedt family, however, SGD had older roots dating back to the construction of the port of Zeebrugge. In the 1970s a major consolidation movement happened in the industry in Europe. In 25 years, the number of European dredging companies dropped from fourteen in 1970 to six by the turn of the century. After the global crisis in the business during the 1980s had been resolved, Dredging International. In 2000 the De Cloedt family was out by the other shareholders. By 2010 Dredging International and Baggerwerken Decloedt & Zoon are two DEME operating companies, the founding companies of DEME have always been active both on their first home market Belgium and abroad
46.
Archimedes' screw
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The Archimedes screw, also called the Archimedean screw or screwpump, is a machine historically used for transferring water from a low-lying body of water into irrigation ditches. Water is pumped by turning a screw-shaped surface inside a pipe, the screw pump is commonly attributed to Archimedes on the occasion of his visit to Egypt. This tradition may reflect only that the apparatus was unknown to the Greeks before Hellenistic times and was introduced in Archimedess lifetime by unknown Greek engineers, some writers have suggested the device may have been in use in Assyria some 350 years earlier. The Archimedes screw consists of a screw inside a hollow pipe, the screw is turned usually by a windmill or by manual labour or by cattle. As the shaft turns, the bottom end scoops up a volume of water and this water is then pushed up the tube by the rotating helicoid until finally it pours out from the top of the tube. If water from one section leaks into the lower one. In some designs, the screw is fused to the casing, a screw could be sealed with pitch resin or other adhesive to its casing, or cast as a single piece in bronze. Some researchers have postulated this as being the device used to irrigate the Hanging Gardens of Babylon, the design of the everyday Greek and Roman water screw, in contrast to the heavy bronze device of Sennacherib, with its problematic drive chains, has a powerful simplicity. A double or triple helix was built of wood strips around a wooden pole. It was used for draining land that was underneath the sea in the Netherlands, Archimedes screws are used in sewage treatment plants because they cope well with varying rates of flow and with suspended solids. An auger in a snow blower or grain elevator is essentially an Archimedes screw, many forms of axial flow pump basically contain an Archimedes screw. The principle is found in pescalators, which are Archimedes screws designed to lift fish safely from ponds. This technology is used primarily at fish hatcheries, where it is desirable to minimize the handling of fish. An Archimedes screw was used in the successful 2001 stabilization of the Leaning Tower of Pisa, small amounts of subsoil saturated by groundwater were removed from far below the north side of the Tower, and the weight of the tower itself corrected the lean. Archimedes screws are used in chocolate fountains. The invention of the screw is credited to Greek polymath Archimedes of Syracuse in the 3rd century BC. A cuneiform inscription of Assyrian king Sennacherib has been interpreted by Stephanie Dalley to describe casting water screws in bronze some 350 years earlier and this is consistent with classical author Strabo, who describes the Hanging Gardens as watered by screws. A contrary view is expressed by Dalley and Oleson, german engineer Konrad Kyeser equips the Archimedes screw with a crank mechanism in his Bellifortis
47.
Venturi effect
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The Venturi effect is the reduction in fluid pressure that results when a fluid flows through a constricted section of a pipe. The Venturi effect is named after Giovanni Battista Venturi, an Italian physicist, thus any gain in kinetic energy a fluid may accrue due to its increased velocity through a constriction is balanced by a drop in pressure. By measuring the change in pressure, the rate can be determined, as in various flow measurement devices such as venturi meters, venturi nozzles. The limiting case of the Venturi effect is when a fluid reaches the state of choked flow, when a fluid system is in a state of choked flow, a further decrease in the downstream pressure environment will not lead to an increase in the mass flow rate. However, mass flow rate for a fluid can increase with increased upstream pressure. This is the principle of operation of a de Laval nozzle, the simplest apparatus, as shown in the photograph and diagram, is a tubular setup known as a Venturi tube or simply a venturi. Fluid flows through a length of pipe of varying diameter, to avoid undue aerodynamic drag, a Venturi tube typically has an entry cone of 30 degrees and an exit cone of 5 degrees. Venturi tubes are used in processes where permanent pressure loss is not tolerable, Venturi tubes are more expensive to construct than a simple orifice plate which uses the same principle as a tubular scheme, but the orifice plate causes significantly more permanent energy loss. Venturis are used in applications and in scientific laboratories for measuring the flow rate of liquids. A venturi can be used to measure the flow rate. At the end of the system, a mixture of liquid, see aspirator and pressure head for discussion of this type of siphon. As fluid flows through a venturi, the expansion and compression of the cause the pressure inside the venturi to change. This principle can be used in metrology for gauges calibrated for differential pressures and this type of pressure measurement may be more convenient, for example, to measure fuel or combustion pressures in jet or rocket engines. In fact, some gusts were so high that travel had to be aided by ropes. Venturi tubes are used to measure the speed of a fluid. Placing a liquid in a U-shaped tube and connecting the ends of the tubes to both ends of a Venturi is all that is needed. When the fluid flows though the Venturi the pressure in the two ends of the tube will differ, forcing the liquid to the low pressure side, the amount of that move can be calibrated to the speed of the fluid flow
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