Arctic char or Arctic charr is a cold-water fish in the family Salmonidae, native to alpine lakes and arctic and subarctic coastal waters. Its distribution is circumpolar, it spawns in fresh water and populations can be lacustrine, riverine or anadromous, where they return from the ocean to their fresh water birth rivers to spawn. No other freshwater fish is found as far north, it is one of the rarest fish species in Britain and Ireland, found in deep, glacial lakes, is at risk from acidification. In other parts of its range, such as the Nordic countries, it is much more common, is fished extensively. In Siberia, it is known as golets and it has been introduced in lakes where it sometimes threatens less hardy endemic species, such as the small-mouth char and the long-finned char in Elgygytgyn Lake; the Arctic char is related to both salmon and lake trout, has many characteristics of both. The fish is variable in colour, depending on the time of year and the environmental conditions of the lake where it lives.
Individual fish can weigh 20 lb or more with record-sized fish having been taken by anglers in northern Canada, where it is known as iqaluk or tariungmiutaq in Inuktitut. Whole market-sized fish are between 2 and 5 lb; the flesh colour can range from a bright red to a pale pink. The arctic char was scientifically described in the salmon genus Salmo as Salmo alpinus by Carl Linnaeus in the 1758 edition of Systema Naturae, the work that established the system of binomial nomenclature for animals. Meanwhile, he described Salmo salvelinus and Salmo umbla, which were considered as synonyms of S. alpinus. John Richardson separated them into a subgenus Salmo; the genus name Salvelinus is from German "Saibling" – little salmon. The English name is thought to derive from Old Irish ceara/cera meaning " red", referring to its pink-red underside; this would connect with its Welsh name torgoch, "red belly". In North America, three subspecies of Salvelinus alpinus have been recognized. "S. a. erythrinus" is native to all of Canada's northern coast.
This subspecies is nearly always anadromous. S. a. oquassa, known as the blueback trout or Sunapee trout, is native to eastern Quebec and northern New England, although it has been extirpated from most of its eastern United States range. S. a. oquassa is never anadromous. Dwarf Arctic char has been classified as S. a. taranetzi. These scientific names are not accepted, however, as the names S. a. erythrinus and S. a. taranetzi refer to subspecies that are endemic to Siberia only. Arctic char are found in Lake Pingualuit in the Ungava Peninsula, Quebec, a lake situated in an impact crater formed 1.4 million years ago. Since the last glaciation, changing water levels are believed to have connected the lake with glacial runoff and surrounding streams and rivers, allowing char to swim upstream into the lake. Arctic char are the only fish found in the lake, signs of fish cannibalism have been found. Arctic char are notable for exhibiting numerous distinct morphological variants or'morphs' throughout the range of the species.
These morphs are sympatric within lakes or rivers. Morphs vary in size and colour. Morphs demonstrate differences in migratory behaviour, being resident or anadromous fish, in feeding behaviour and niche placement. Morphs interbreed, but they can be reproductively isolated and represent genetically distinct populations, which have been cited as examples of incipient speciation. In Iceland, Þingvallavatn is noted for the evolution of four morphs: small benthic, large benthic, small limnetic and large limnetic. In Svalbard, Lake Linne´vatn on Spitsbergen has dwarf,'normal', normal-sized anadromous fish, Lake Ellasjøen on Bear Island has a dwarf, small littoral and large pelagic morph. Spawning takes place from September to November over rocky shoals in lakes with heavy wave action and in slower gravel-bottom pools in rivers; as with most salmonids, vast differences in coloration and body shape occur between sexually mature males and females. Males take on a brilliant red colour. Females remain silver.
Most males set up and guard territories and spawn with several females. The female redd. A female anadromous char deposits from 3,000 to 5,000 eggs. Char do not die after spawning like Pacific salmon and spawn several times throughout their lives every second or third year. Young char emerge from the gravel in spring and stay in the river from 5 to 7 months or until they are about 6–8 in in length; the char diet varies with the seasons. During late spring and summer, they feed on insects found on the water's surface, salmon eggs and other smaller crustaceans found on the lake bottom, smaller fish up to a third of the char's size. During the autumn and winter months the char feeds on zooplankton and freshwater shrimps that are suspended in the lake and occasionally feeds on smaller fish. Research aimed at determining the suitability of Arctic char as a cultured species has been going on since the late 1970s; the Canadian government's Freshwater Institute of Fisheries and Oceans Canada at Winnipeg and the Huntsman Marine Science Centre of New Brunswick, pioneered the early efforts in Canada.
Arctic char are farmed in Iceland, Norway, Finland, West Virginia, Ireland. Arctic char were first investigated because they were expected to have low optimum temp
France the French Republic, is a country whose territory consists of metropolitan France in Western Europe and several overseas regions and territories. The metropolitan area of France extends from the Mediterranean Sea to the English Channel and the North Sea, from the Rhine to the Atlantic Ocean, it is bordered by Belgium and Germany to the northeast and Italy to the east, Andorra and Spain to the south. The overseas territories include French Guiana in South America and several islands in the Atlantic and Indian oceans; the country's 18 integral regions span a combined area of 643,801 square kilometres and a total population of 67.3 million. France, a sovereign state, is a unitary semi-presidential republic with its capital in Paris, the country's largest city and main cultural and commercial centre. Other major urban areas include Lyon, Toulouse, Bordeaux and Nice. During the Iron Age, what is now metropolitan France was inhabited by a Celtic people. Rome annexed the area in 51 BC, holding it until the arrival of Germanic Franks in 476, who formed the Kingdom of Francia.
The Treaty of Verdun of 843 partitioned Francia into Middle Francia and West Francia. West Francia which became the Kingdom of France in 987 emerged as a major European power in the Late Middle Ages following its victory in the Hundred Years' War. During the Renaissance, French culture flourished and a global colonial empire was established, which by the 20th century would become the second largest in the world; the 16th century was dominated by religious civil wars between Protestants. France became Europe's dominant cultural and military power in the 17th century under Louis XIV. In the late 18th century, the French Revolution overthrew the absolute monarchy, established one of modern history's earliest republics, saw the drafting of the Declaration of the Rights of Man and of the Citizen, which expresses the nation's ideals to this day. In the 19th century, Napoleon established the First French Empire, his subsequent Napoleonic Wars shaped the course of continental Europe. Following the collapse of the Empire, France endured a tumultuous succession of governments culminating with the establishment of the French Third Republic in 1870.
France was a major participant in World War I, from which it emerged victorious, was one of the Allies in World War II, but came under occupation by the Axis powers in 1940. Following liberation in 1944, a Fourth Republic was established and dissolved in the course of the Algerian War; the Fifth Republic, led by Charles de Gaulle, remains today. Algeria and nearly all the other colonies became independent in the 1960s and retained close economic and military connections with France. France has long been a global centre of art and philosophy, it hosts the world's fourth-largest number of UNESCO World Heritage Sites and is the leading tourist destination, receiving around 83 million foreign visitors annually. France is a developed country with the world's sixth-largest economy by nominal GDP, tenth-largest by purchasing power parity. In terms of aggregate household wealth, it ranks fourth in the world. France performs well in international rankings of education, health care, life expectancy, human development.
France is considered a great power in global affairs, being one of the five permanent members of the United Nations Security Council with the power to veto and an official nuclear-weapon state. It is a leading member state of the European Union and the Eurozone, a member of the Group of 7, North Atlantic Treaty Organization, Organisation for Economic Co-operation and Development, the World Trade Organization, La Francophonie. Applied to the whole Frankish Empire, the name "France" comes from the Latin "Francia", or "country of the Franks". Modern France is still named today "Francia" in Italian and Spanish, "Frankreich" in German and "Frankrijk" in Dutch, all of which have more or less the same historical meaning. There are various theories as to the origin of the name Frank. Following the precedents of Edward Gibbon and Jacob Grimm, the name of the Franks has been linked with the word frank in English, it has been suggested that the meaning of "free" was adopted because, after the conquest of Gaul, only Franks were free of taxation.
Another theory is that it is derived from the Proto-Germanic word frankon, which translates as javelin or lance as the throwing axe of the Franks was known as a francisca. However, it has been determined that these weapons were named because of their use by the Franks, not the other way around; the oldest traces of human life in what is now France date from 1.8 million years ago. Over the ensuing millennia, Humans were confronted by a harsh and variable climate, marked by several glacial eras. Early hominids led a nomadic hunter-gatherer life. France has a large number of decorated caves from the upper Palaeolithic era, including one of the most famous and best preserved, Lascaux. At the end of the last glacial period, the climate became milder. After strong demographic and agricultural development between the 4th and 3rd millennia, metallurgy appeared at the end of the 3rd millennium working gold and bronze, iron. France has numerous megalithic sites from the Neolithic period, including the exceptiona
The Eurasian minnow, minnow, or common minnow is a small species of freshwater fish in the carp family Cyprinidae. It is the type species of genus Phoxinus, it is ubiquitous throughout much of Eurasia, from Britain and Spain to eastern Siberia, predominantly in cool streams and well-oxygenated lakes and ponds. It is noted for being a gregarious species, shoaling in large numbers; the common minnow is a small fish which reaches a maximum total length of 14 cm, but is around 7 cm in length. It has 6-8 soft rays in its anal fin, its spine is made up of 38-40 vertebrae. It is distinguished from similar species which occur in Europe by having the lateral line extending beyond the nase of the anal fin, by a line of vertically elongated blotches along the lateral line each with a depth equivalent to 1/3-1/2 of the body's depth at same position, these blotches fuse to form a midlateral stripe, caudal peduncle has a depth of 2.6-3.1 times its length. The scales on the breast are patchy and the patches of scales are separated by unscaled areas although they are connected by 1-2 rows of scales.
Its snout length is 1.1-1.4 times the diameter of the eye. The anal fin has its origin in front of the base of the last dorsal ray; the caudal fin consists of 19 soft rays. The back is brownish-green, is separated from the whitish-gray underside by the lateral stripe or blotches described above, The common minnow is found in northern Eurasia from Ireland in the west east to the Amur drainage and Korea. In Great Britain occurs to 58°N and in Scandinavia and Russia occur up to the northernmost extremities. In western Europe the southern limit appears to be the upper Rhone, it has been recorded in the drainages of the Volga and the Ural, as well as in Lake Balkhash and the upper Syr-Darya drainage. Records else where require confirmation as this species is similar to a number of others. In Scotland it is regarded as an introduced non native species, this is the case in Ireland. Introductions are to have occurred elsewhere, including Norway; the common minnow is found in a wide variety of habitats that have cold, well oxygenated water in the same habitats as salmonids.
These include small streams with fast currents, and, in the more northerly parts of its range, large lowland rivers. It lives in still waters as varied as small mountain lakes to large, oligotrophic lakes. For spawning, it requires clean gravel areas in well oxygenated flowing water or where waves wash on lake shores, it needs deep pools with low current to overwinter in, these must have a coarse substrate among which the fish can hide. Shoaling and schooling behavior of common minnows occur early in their development, as soon as they become capable of swimming. Shoaling behavior increases and becomes dominant by three to four weeks after its emergence; this behavior benefits individual minnows by improving predator avoidance and foraging. However, there are costs of living in groups such as increased competition for food and risk of infection. Shoaling behavior is modified depending on the situation such as presence of predators or resource availability; the group formation of common minnows can be explained by the selfish herd effect proposed by W.
D. Hamilton. According to the selfish herd theory, a group forms as individuals try to reduce their domain of danger by approaching others and continuously moving toward the center of the group where the risk of predation is the lowest; as the theory predicts, common minnows increase their shoaling behavior in response to increased predation pressure. Common minnows can detect the predators’ presence and communicate with their shoalmates by a chemical signal, detected by olfactory nerves; the chemical, named Schreckstoff after a German word meaning "fear substance" by Karl von Frisch who first described it, is contained in specialized skin cells called alarm substance cells and is released from an injured or killed minnow. The shoalmates can respond to the increased risk of predation; the production and release of this alarm substance are altruistic because the sender of the signal, who does not directly benefit from the signal released upon its injury, has to pay the cost for the production and release of the chemical.
In fact, the alarm substance cells decrease in number when the common minnows are in poor physical condition due to scarce food, indicating that there is metabolic cost for producing and maintaining the specialized cells. The apparent altruistic behavior is not understood, because the explanation of kin selection is not supported by the shoal structure of common minnows in which shoalmates are not closely related; when common minnows sense the alarm substance, they form tighter shoals as individuals move to be in the central position in their shoaling group. However, in an experiment where common minnows were habituated to the chemical by continuous exposure, common minnows did not react to the signal. Only the naïve common minnows reacted to the signal by relocating themselves to the central position in the group. In another experiment, researchers observed common minnows in semi-natural setting and found that common minnows’ shoaling behavior varies depending on the habitat's complexity. Minnows tend to respond to increased predation risk by forming larger shoals in structurally simple habitats and by reducing their rate of movement in complex habitats.
When potential predators come near the shoal, some common minnows take the risk of approaching the predators in order to inspect the predator and assess the danger. Predator inspection behavior increases the risk of being attacked an
Hydraulic head or piezometric head is a specific measurement of liquid pressure above a vertical datum. It is measured as a liquid surface elevation, expressed in units of length, at the entrance of a piezometer. In an aquifer, it can be calculated from the depth to water in a piezometric well, given information of the piezometer's elevation and screen depth. Hydraulic head can be measured in a column of water using a standpipe piezometer by measuring the height of the water surface in the tube relative to a common datum; the hydraulic head can be used to determine a hydraulic gradient between two or more points. In fluid dynamics, head is a concept that relates the energy in an incompressible fluid to the height of an equivalent static column of that fluid. From Bernoulli's Principle, the total energy at a given point in a fluid is the energy associated with the movement of the fluid, plus energy from static pressure in the fluid, plus energy from the height of the fluid relative to an arbitrary datum.
Head is expressed in units of height such as feet. The static head of a pump is the maximum height; the capability of the pump at a certain RPM can be read from its Q-H curve. A common misconception is that the head equals the fluid's energy per unit weight, while, in fact, the term with pressure does not represent any type of energy. Head is useful in specifying centrifugal pumps because their pumping characteristics tend to be independent of the fluid's density. There are four types of head used to calculate the total head in and out of a pump: Velocity head is due to the bulk motion of a fluid, its pressure head correspondent is the dynamic pressure. Elevation head is due to the gravitational force acting on a column of fluid. Pressure head is due to the static pressure, the internal molecular motion of a fluid that exerts a force on its container. Resistance head is due to the frictional forces acting against a fluid's motion by the container. A mass free falling from an elevation z > 0 will reach a speed v = 2 g z, when arriving at elevation z=0, or when we rearrange it as a head: h = v 2 2 g where g is the acceleration due to gravityThe term v 2 2 g is called the velocity head, expressed as a length measurement.
In a flowing fluid, it represents the energy of the fluid due to its bulk motion. The total hydraulic head of a fluid is composed of elevation head; the pressure head is the equivalent gauge pressure of a column of water at the base of the piezometer, the elevation head is the relative potential energy in terms of an elevation. The head equation, a simplified form of the Bernoulli Principle for incompressible fluids, can be expressed as: h = ψ + z where h is the hydraulic head known as the piezometric head. Ψ is the pressure head, in terms of the elevation difference of the water column relative to the piezometer bottom, z is the elevation at the piezometer bottom In an example with a 400 m deep piezometer, with an elevation of 1000 m, a depth to water of 100 m: z = 600 m, ψ = 300 m, h = 900 m. The pressure head can be expressed as: ψ = P γ = P ρ g where P is the gauge pressure, γ is the unit weight of the liquid, ρ is the density of the liquid, g is the gravitational acceleration The pressure head is dependent on the density of water, which can vary depending on both the temperature and chemical composition.
This means that the hydraulic head calculation is dependent on the density of the water within the piezometer. If one or more hydraulic head measurements are to be compared, they need to be standardized to their fresh water head, which can be calculated as: h f w = ψ ρ ρ f w + z where h f w is the fresh water head, ρ f w is the density of fresh water The hydraulic gradient is a vector gradient between two or more hydraulic head measurements over the length of the flow path. For groundwater, it is called the'Darcy slope', since it determines the quantity of a Darcy flux or discharge, it has applications in open-channel flow
Électricité de France
Électricité de France S. A. is a French electric utility company owned by the French state. Headquartered in Paris, with €71.2 billion in revenues in 2016, EDF operates a diverse portfolio of 120+ gigawatts of generation capacity in Europe, South America, North America, the Middle East and Africa. In 2009, EDF was the world's largest producer of electricity. In 2011, it produced 22% of the European Union's electricity from nuclear power: nuclear: 64.3%. Its 58 active nuclear reactors are spread out over 20 sites, they comprise 34 reactors of 900 MWe, 20 reactors of 1300 MWe, 4 reactors of 1450 MWe, all PWRs. In 2017 EDF took over the majority of the reactor business of Areva, in a French government sponsored restructuring following financial and technical problems at Areva. In July 2017, France's Environmental Minister Nicolas Hulot stated that up to 17 of France's nuclear power reactors — all of which are operated by EDF — could be shuttered by 2025 to meet legislative targets for reducing dependence on the power source.
EDF specialises from engineering to distribution. The company's operations include the following: distribution, it is active in such power generation technologies as nuclear power, marine energies, wind power, solar energy, geothermal energy and fossil-fired energy. The electricity network in France is composed of the following: a high and high voltage distribution system; this part of the system is managed by RTE who acts as an independent administrator of infrastructure, although it is a wholly owned subsidiary of EDF. Enedis was spun off from EDF-Gaz de France Distribution in 2008 as part of the process of total separation of the activities of EDF and GDF Suez; the EDF head office is located along Avenue de Wagram in the 8th arrondissement of Paris. The EDF head office is shared between several EDF sites in Greater Paris. Chairman and CEO: Jean-Bernard Levy Customers: 37.6 million worldwide in 2015. 2009 Turnover: €63.34 billion – €41.82 billion in 2002. Profit: €3.96 billion in 2010 – €3.96 billion in 2009.
Net profit: €1 billion in 2010 – €3.92 billion in 2009. Net Debt: €34.4 billion in 2010 – €42.5 billion in 2009. Revenue: €75 billion in 2015. Energy generation: 619.3 TWh in 2015. Employees: 159,112 worldwide. In Europe: United Kingdom: 100% EDF Energy, acquired British Energy Group PLC, which generates about 20 percent of British electricity from 8 nuclear plants, 100% EDF Trading Austria: 100% Vero, 20% Groupe Estag Belgium: 100% Luminus France: 100% of EDF Énergies Nouvelles which in turn owns EDF-RE EnXco in US, 74.86% Électricité de Strasbourg, 67% Dalkia Investments, 51% TIRU, 50% Cerga, 50% Edenkia, 50% Dalkia International, 50% SIIF Énergies, 34% Dalkia Hdg Germany: 100% EDF Ostalbkreis, 100% EDF Weinsberg, 50% RKI Hungary: 95,56% BE Zrt, 100% Démász Italy: Edison S.p. A. 100% EDF Energia Italia which sells directly 2.2 TWh to Italy, 100% EDF Fenice, 40% Finei, 30% ISE The Netherlands: 100% Finelex, 50% Cinergy Holding Poland: 76.63% Rybnik, 66.08% ECK, 49.19% ECW, 35.42% Kogeneracja, 24.61% Zielona Gora Slovakia: 49% SSE Spain: 100% EDF Iberica Sweden: 100% Skandrenkraft, 36.32% Groupe Graninge Switzerland: 50% Chatelot, 50% Emosson, 14.25% Groupe ATEL, 26.26% Motor Columbus In America: United States: 100% EDF Inc. which controls or Unistar Nuclear Energy, EDF-RE EnXco, EDF Trading North America and Constellation Energy Nuclear Group (50% through a joint venture with Exelon Argentina: 25% Edenor, 45% Sodemsa, 22.95% Edemsa Brazil: 100% Lidil, 90% Norte Fluminense In Asia: China: 85% Synergie, 60% Figlec, 35% Datang Sanmenxia Power Company, 19.6% Shandong Zhonghua Power Company Vietnam: 56.25% Meco In Africa: Côte d'Ivoire: 50% Azito O&M, 32.85% Azito Energie EDF was founded on 8 April 1946, as a result of the nationalisation of around 1,700 smaller energy producers and distributors by the Minister of Industrial Production Marcel Paul.
A state-owned EPIC, it became the main electricity generation and distribution company in France, enjoying a monopoly in electricity generation, although some small local distributors were retained by the nationalisation. This monopoly ended in 1999, when EDF was forced by a European Directive to open up 20% of its business to competitors; until 19 November 2004, EDF was a state-owned corporation, but it is now a limited-liability corporation under private law, after its status was changed by statute. The French government floated shares of the company on the Paris Stock Exchange in November 2005, although it retained 85% ownership as of the end of 2008. On 22 November 2016, French competition regulators raided EDF offices, looking for evidence that EDF was abusing its dominant position to manipulate electricity prices and squeeze rivals. Between 2001 and 2003, EDF was forced to reduce its equity capital by €6.4 billion total because of the performance of subsidiaries in South America and Europe.
In 2001, it acquired a number of British energy companies, becoming the UK's biggest electricity supplier. The company remains in debt, its profitability suffered during the recession which began in 2008. It made €3.9 billion in 2009, which fell to €1.02 billion in 2010, with pr