1.
Alloy
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An alloy is a mixture of metals or a mixture of a metal and another element. Alloys are defined by a metallic bonding character, an alloy may be a solid solution of metal elements or a mixture of metallic phases. Intermetallic compounds are alloys with a stoichiometry and crystal structure. Zintl phases are sometimes considered alloys depending on bond types. Alloys are used in a variety of applications. In some cases, a combination of metals may reduce the overall cost of the material while preserving important properties, in other cases, the combination of metals imparts synergistic properties to the constituent metal elements such as corrosion resistance or mechanical strength. Examples of alloys are steel, solder, brass, pewter, duralumin, bronze, the alloy constituents are usually measured by mass. Alloys are usually classified as substitutional or interstitial alloys, depending on the arrangement that forms the alloy. They can be classified as homogeneous, or heterogeneous or intermetallic. An alloy is a mixture of elements, which forms an impure substance that retains the characteristics of a metal. Alloys are made by mixing two or more elements, at least one of which is a metal and this is usually called the primary metal or the base metal, and the name of this metal may also be the name of the alloy. The other constituents may or may not be metals but, when mixed with the base, they will be soluble. The mechanical properties of alloys will often be different from those of its individual constituents. A metal that is very soft, such as aluminium, can be altered by alloying it with another soft metal. Although both metals are soft and ductile, the resulting aluminium alloy will have much greater strength. Adding a small amount of carbon to iron trades its great ductility for the greater strength of an alloy called steel. Due to its strength, but still substantial toughness, and its ability to be greatly altered by heat treatment, steel is one of the most useful. By adding chromium to steel, its resistance to corrosion can be enhanced, creating stainless steel, while adding silicon will alter its electrical characteristics, producing silicon steel
2.
Copper
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Copper is a chemical element with symbol Cu and atomic number 29. It is a soft, malleable, and ductile metal with high thermal and electrical conductivity. A freshly exposed surface of copper has a reddish-orange color. Copper is one of the few metals that occur in nature in directly usable metallic form as opposed to needing extraction from an ore and this led to very early human use, from c.8000 BC. Copper used in buildings, usually for roofing, oxidizes to form a green verdigris, Copper is sometimes used in decorative art, both in its elemental metal form and in compounds as pigments. Copper compounds are used as agents, fungicides, and wood preservatives. Copper is essential to all living organisms as a trace dietary mineral because it is a key constituent of the enzyme complex cytochrome c oxidase. In molluscs and crustaceans, copper is a constituent of the blood pigment hemocyanin, replaced by the hemoglobin in fish. In humans, copper is found mainly in the liver, muscle, the adult body contains between 1.4 and 2.1 mg of copper per kilogram of body weight. The filled d-shells in these elements contribute little to interatomic interactions, unlike metals with incomplete d-shells, metallic bonds in copper are lacking a covalent character and are relatively weak. This observation explains the low hardness and high ductility of single crystals of copper, at the macroscopic scale, introduction of extended defects to the crystal lattice, such as grain boundaries, hinders flow of the material under applied stress, thereby increasing its hardness. For this reason, copper is supplied in a fine-grained polycrystalline form. The softness of copper partly explains its high conductivity and high thermal conductivity. The maximum permissible current density of copper in open air is approximately 3. 1×106 A/m2 of cross-sectional area, Copper is one of a few metallic elements with a natural color other than gray or silver. Pure copper is orange-red and acquires a reddish tarnish when exposed to air, as with other metals, if copper is put in contact with another metal, galvanic corrosion will occur. A green layer of verdigris can often be seen on old structures, such as the roofing of many older buildings. Copper tarnishes when exposed to sulfur compounds, with which it reacts to form various copper sulfides. There are 29 isotopes of copper, 63Cu and 65Cu are stable, with 63Cu comprising approximately 69% of naturally occurring copper, both have a spin of 3⁄2
3.
Nickel
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Nickel is a chemical element with symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a golden tinge. Nickel belongs to the metals and is hard and ductile. Meteoric nickel is found in combination with iron, a reflection of the origin of elements as major end products of supernova nucleosynthesis. An iron–nickel mixture is thought to compose Earths inner core, use of nickel has been traced as far back as 3500 BCE. Nickel was first isolated and classified as an element in 1751 by Axel Fredrik Cronstedt. The elements name comes from a mischievous sprite of German miner mythology, Nickel, an economically important source of nickel is the iron ore limonite, which often contains 1–2% nickel. Nickels other important ore minerals include garnierite, and pentlandite, major production sites include the Sudbury region in Canada, New Caledonia in the Pacific, and Norilsk in Russia. Nickel is slowly oxidized by air at room temperature and is considered corrosion-resistant, historically, it has been used for plating iron and brass, coating chemistry equipment, and manufacturing certain alloys that retain a high silvery polish, such as German silver. About 6% of world production is still used for corrosion-resistant pure-nickel plating. Nickel-plated objects sometimes provoke nickel allergy, Nickel has been widely used in coins, though its rising price has led to some replacement with cheaper metals in recent years. Nickel is one of four elements that are ferromagnetic around room temperature, alnico permanent magnets based partly on nickel are of intermediate strength between iron-based permanent magnets and rare-earth magnets. The metal is valuable in modern times chiefly in alloys, about 60% of world production is used in nickel-steels, other common alloys and some new superalloys comprise most of the remainder of world nickel use, with chemical uses for nickel compounds consuming less than 3% of production. As a compound, nickel has a number of chemical manufacturing uses. Nickel is a nutrient for some microorganisms and plants that have enzymes with nickel as an active site. Nickel is a metal with a slight golden tinge that takes a high polish. It is one of four elements that are magnetic at or near room temperature. Its Curie temperature is 355 °C, meaning that bulk nickel is non-magnetic above this temperature, the unit cell of nickel is a face-centered cube with the lattice parameter of 0.352 nm, giving an atomic radius of 0.124 nm
4.
Iron
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Iron is a chemical element with symbol Fe and atomic number 26. It is a metal in the first transition series and it is by mass the most common element on Earth, forming much of Earths outer and inner core. It is the fourth most common element in the Earths crust, like the other group 8 elements, ruthenium and osmium, iron exists in a wide range of oxidation states, −2 to +6, although +2 and +3 are the most common. Elemental iron occurs in meteoroids and other low oxygen environments, but is reactive to oxygen, fresh iron surfaces appear lustrous silvery-gray, but oxidize in normal air to give hydrated iron oxides, commonly known as rust. Unlike the metals that form passivating oxide layers, iron oxides occupy more volume than the metal and thus flake off, Iron metal has been used since ancient times, although copper alloys, which have lower melting temperatures, were used even earlier in human history. Pure iron is soft, but is unobtainable by smelting because it is significantly hardened and strengthened by impurities, in particular carbon. A certain proportion of carbon steel, which may be up to 1000 times harder than pure iron. Crude iron metal is produced in blast furnaces, where ore is reduced by coke to pig iron, further refinement with oxygen reduces the carbon content to the correct proportion to make steel. Steels and iron alloys formed with metals are by far the most common industrial metals because they have a great range of desirable properties. Iron chemical compounds have many uses, Iron oxide mixed with aluminium powder can be ignited to create a thermite reaction, used in welding and purifying ores. Iron forms binary compounds with the halogens and the chalcogens, among its organometallic compounds is ferrocene, the first sandwich compound discovered. Iron plays an important role in biology, forming complexes with oxygen in hemoglobin and myoglobin. Iron is also the metal at the site of many important redox enzymes dealing with cellular respiration and oxidation and reduction in plants. A human male of average height has about 4 grams of iron in his body and this iron is distributed throughout the body in hemoglobin, tissues, muscles, bone marrow, blood proteins, enzymes, ferritin, hemosiderin, and transport in plasma. The mechanical properties of iron and its alloys can be evaluated using a variety of tests, including the Brinell test, Rockwell test, the data on iron is so consistent that it is often used to calibrate measurements or to compare tests. An increase in the content will cause a significant increase in the hardness. Maximum hardness of 65 Rc is achieved with a 0. 6% carbon content, because of the softness of iron, it is much easier to work with than its heavier congeners ruthenium and osmium. Because of its significance for planetary cores, the properties of iron at high pressures and temperatures have also been studied extensively
5.
Manganese
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Manganese is a chemical element with symbol Mn and atomic number 25. It is not found as an element in nature, it is often found in minerals in combination with iron. Manganese is a metal with important industrial metal alloy uses, particularly in stainless steels, by the mid-18th century, Swedish chemist Carl Wilhelm Scheele had used pyrolusite to produce chlorine. Scheele and others were aware that pyrolusite contained a new element, johan Gottlieb Gahn was the first to isolate an impure sample of manganese metal in 1774, which he did by reducing the dioxide with carbon. Manganese phosphating is used for rust and corrosion prevention on steel, ionized manganese is used industrially as pigments of various colors, which depend on the oxidation state of the ions. The permanganates of alkali and alkaline earth metals are powerful oxidizers, Manganese dioxide is used as the cathode material in zinc-carbon and alkaline batteries. In biology, manganese ions function as cofactors for a variety of enzymes with many functions. Manganese enzymes are essential in detoxification of superoxide free radicals in organisms that must deal with elemental oxygen. Manganese also functions in the complex of photosynthetic plants. The element is a trace mineral for all known living organisms but is a neurotoxin. In larger amounts, and apparently with far greater effectiveness through inhalation, Manganese is a silvery-gray metal that resembles iron. It is hard and very brittle, difficult to fuse, Manganese metal and its common ions are paramagnetic. Manganese tarnishes slowly in air and oxidizes like iron in water containing dissolved oxygen, naturally occurring manganese is composed of one stable isotope, 55Mn. Eighteen radioisotopes have been isolated and described, the most stable being 53Mn with a half-life of 3.7 million years, 54Mn with a half-life of 312.3 days, and 52Mn with a half-life of 5.591 days. All of the radioactive isotopes have half-lives of less than three hours, and the majority of less than one minute. Manganese also has three meta states, Manganese is part of the iron group of elements, which are thought to be synthesized in large stars shortly before the supernova explosion. 53Mn decays to 53Cr with a half-life of 3.7 million years, because of its relatively short half-life, 53Mn is relatively rare, produced by cosmic rays impact on iron. Manganese isotopic contents are combined with chromium isotopic contents and have found application in isotope geology
6.
Seawater
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Seawater, or salt water, is water from a sea or ocean. On average, seawater in the oceans has a salinity of about 3. 5% This means that every kilogram of seawater has approximately 35 grams of dissolved salts. Average density at the surface is 1.025 kg/l, seawater is denser than both fresh water and pure water because the dissolved salts increase the mass by a larger proportion than the volume. The freezing point of seawater decreases as salt concentration increases, at typical salinity, it freezes at about −2 °C. The coldest seawater ever recorded was in 2010, in a stream under an Antarctic glacier, seawater pH is typically limited to a range between 7.5 and 8.4. However, there is no universally accepted reference pH-scale for seawater, although the vast majority of seawater has a salinity of between 31 g/kg and 38 g/kg, seawater is not uniformly saline throughout the world. Where mixing occurs with fresh water runoff from river mouths, near melting glaciers or vast amounts precipitation, the most saline open sea is the Red Sea, where high rates of evaporation, low precipitation and low river run-off, and confined circulation result in unusually salty water. The salinity in isolated bodies of water can be considerably greater still, historically, several salinity scales were used to approximate the absolute salinity of seawater. A popular scale was the Practical Salinity Scale where salinity was measured in practical salinity units, the current standard for salinity is the Reference Salinity scale with the salinity expressed in units of g/kg. The density of surface seawater ranges from about 1020 to 1029 kg/m3, depending on the temperature, at a temperature of 25 °C, salinity of 35 g/kg and 1 atm pressure, the density of seawater is 1023.6 kg/m3. Deep in the ocean, under pressure, seawater can reach a density of 1050 kg/m3 or higher. The density of seawater also changes with salinity, brines generated by seawater desalination plants can have salinities up to 120 g/kg. The density of typical seawater brine of 120 g/kg salinity at 25 °C, seawater pH is limited to the range 7.5 to 8.4. The speed of sound in seawater is about 1,500 m/s, and varies with temperature, salinity. The thermal conductivity of seawater is 0.6 W/mK at 25 °C, the thermal conductivity decreases with increasing salinity and increases with increasing temperature. Seawater contains more dissolved ions than all types of freshwater, however, the ratios of solutes differ dramatically. Bicarbonate ions also constitute 48% of river water solutes but only 0. 14% of all seawater ions, differences like these are due to the varying residence times of seawater solutes, sodium and chlorine have very long residence times, while calcium tends to precipitate much more quickly. The most abundant dissolved ions in seawater are sodium, chloride, magnesium, sulfate and its osmolarity is about 1000 mOsm/l
7.
Propeller
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A propeller is a type of fan that transmits power by converting rotational motion into thrust. A pressure difference is produced between the forward and rear surfaces of the blade, and a fluid is accelerated behind the blade. Their disadvantages are higher mechanical complexity and higher cost, the principle employed in using a screw propeller is used in sculling. It is part of the skill of propelling a Venetian gondola but was used in a less refined way in parts of Europe. For example, propelling a canoe with a paddle using a pitch stroke or side slipping a canoe with a scull involves a similar technique. In China, sculling, called lu, was used by the 3rd century AD. In sculling, a blade is moved through an arc. The innovation introduced with the propeller was the extension of that arc through more than 360° by attaching the blade to a rotating shaft. Propellers can have a blade, but in practice there are nearly always more than one so as to balance the forces involved. The origin of the screw propeller starts with Archimedes, who used a screw to lift water for irrigation and bailing boats and it was probably an application of spiral movement in space to a hollow segmented water-wheel used for irrigation by Egyptians for centuries. Leonardo da Vinci adopted the principle to drive his theoretical helicopter, in 1784, J. P. Paucton proposed a gyrocopter-like aircraft using similar screws for both lift and propulsion. At about the time, James Watt proposed using screws to propel boats. This was not his own invention, though, Toogood and Hays had patented it a century earlier, by 1827, Czech-Austrian inventor Josef Ressel had invented a screw propeller which had multiple blades fastened around a conical base. He had tested his propeller in February 1826 on a ship that was manually driven. He was successful in using his bronze screw propeller on an adapted steamboat and his ship Civetta with 48 gross register tons, reached a speed of about six knots. This was the first ship successfully driven by an Archimedes screw-type propeller, after a new steam engine had an accident his experiments were banned by the Austro-Hungarian police as dangerous. Josef Ressel was at the time a forestry inspector for the Austrian Empire, but before this he received an Austro-Hungarian patent for his propeller. This new method of propulsion was an improvement over the paddlewheel as it was not so affected by either ship motions or changes in draft as the burned coal
8.
Crankshaft
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A crankshaft—related to crank—is a mechanical part able to perform a conversion between reciprocating motion and rotational motion. In a reciprocating engine, it translates reciprocating motion of the piston into rotational motion, whereas in a reciprocating compressor, a Roman iron crank of yet unknown purpose dating to the 2nd century AD was excavated in Augusta Raurica, Switzerland. The 82.5 cm long piece has fitted to one end a 15 cm long bronze handle, the accompanying inscription is in Greek. The crank and connecting rod mechanisms of the other two archaeologically attested sawmills worked without a gear train, al-Jazari described a crank and connecting rod system in a rotating machine in two of his water-raising machines. His twin-cylinder pump incorporated a crankshaft, though the device was unnecessarily complex, the Italian physician Guido da Vigevano, planning for a new crusade, made illustrations for a paddle boat and war carriages that were propelled by manually turned compound cranks and gear wheels. In Renaissance Italy, the earliest evidence of a crank and connecting-rod is found in the sketch books of Taccola. A sound grasp of the motion involved is demonstrated a little later by Pisanello. One of the drawings of the Anonymous of the Hussite Wars shows a boat with a pair of paddle-wheels at each end turned by men operating compound cranks. Crankshafts were also described by Konrad Kyeser, Leonardo da Vinci and his wind-powered sawmill used a crankshaft to convert a windmills circular motion into a back-and-forward motion powering the saw. Corneliszoon was granted a patent for his crankshaft in 1597, large engines are usually multicylinder to reduce pulsations from individual firing strokes, with more than one piston attached to a complex crankshaft. Many small engines, such as found in mopeds or garden machinery, are single cylinder and use only a single piston. A crankshaft is subjected to stresses, potentially equivalent of several tonnes of force. The crankshaft is connected to the fly-wheel, the block, using bearings on the main journals. An engine loses up to 75% of its energy in the form of friction, noise and vibration in the crankcase. The remaining losses occur in the heat and blow by. The crankshaft has a linear axis about which it rotates, typically with several bearing journals riding on replaceable bearings held in the engine block. As the crankshaft undergoes a great deal of sideways load from each cylinder in an engine, it must be supported by several such bearings. This was a factor in the rise of V8 engines, with their shorter crankshafts, the long crankshafts of the latter suffered from an unacceptable amount of flex when engine designers began using higher compression ratios and higher rotational speeds
9.
Hull (watercraft)
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The hull is the watertight body of a ship or boat. Above the hull is the superstructure and/or deckhouse, where present, the line where the hull meets the water surface is called the waterline. The structure of the hull varies depending on the vessel type, the uppermost continuous deck may be called the upper deck, weather deck, spar deck, main deck, or simply deck. The particular name given depends on the type of ship or boat. In a typical wooden sailboat, the hull is constructed of wooden planking, supported by transverse frames and bulkheads, often but not always there is a centerline longitudinal member called a keel. In fiberglass or composite hulls, the structure may resemble wooden or steel vessels to some extent, in many cases, composite hulls are built by sandwiching thin fiber-reinforced skins over a lightweight but reasonably rigid core of foam, balsa wood, impregnated paper honeycomb or other material. The shape of the hull is entirely dependent upon the needs of the design, shapes range from a nearly perfect box in the case of scow barges, to a needle-sharp surface of revolution in the case of a racing multihull sailboat. Hulls come in varieties and can have composite shape, but are grouped primarily as follows. Examples are the flat-bottom, v-bottom, and multi-bottom hull and these types have at least one pronounced knuckle throughout all or most of their length. These hull shapes all have smooth curves, examples are the round bilge, semi-round bilge, and s-bottom hull. After this they can be categorized as, Displacement The hull is supported exclusively or predominantly by buoyancy, vessels that have this type of hull travel through the water at a limited rate that is defined by the waterline length. They are often, though not always, heavier than planing types, planing The planing hull form is configured to develop positive dynamic pressure so that its draft decreases with increasing speed. The dynamic lift reduces the surface and therefore also the drag. They are sometimes flat-bottomed, sometimes V-bottomed and more rarely, round-bilged, the most common form is to have at least one chine, which makes for more efficient planing and can throw spray down. Planing hulls are more efficient at speeds, although they still require more energy to achieve these speeds. An effective planing hull must be as light as possible with flat surfaces that are consistent with sea keeping. Sail boats that plane must also sail efficiently in displacement mode in light winds, semi-displacement, or semi-planing The hull form is capable of developing a moderate amount of dynamic lift, however, most of the vessels weight is still supported through buoyancy. At present, the most widely used form is the round bilge hull, in the inverted bell shape of the hull, with a smaller payload the waterline cross-section is less, hence the resistance is less and the speed is higher
10.
Tugboat
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A tug is a boat or ship that maneuvers vessels by pushing or towing them. Tugboats are powerful for their size and strongly built, and some are ocean-going, some tugboats serve as icebreakers or salvage boats. Early tugboats had steam engines, but today most have diesel engines, many tugboats have firefighting monitors, allowing them to assist in firefighting, especially in harbors. Seagoing tugs fall into four categories, The standard seagoing tug with model bow that tows its payload on a hawser. The notch tug which can be secured in a notch at the stern of a specially designed barge and this configuration is dangerous to use with a barge which is in ballast or in a head- or following sea. Therefore, notch tugs are usually built with a towing winch and these units stay combined under virtually any sea conditions and the tugs usually have poor sea-keeping designs for navigation without their barges attached. Vessels in this category are considered to be ships rather than tugboats. These vessels must show navigation lights compliant with those required of ships rather than required of tugboats. Articulated tug and barge units also utilize mechanical means to connect to their barges, the tug slips into a notch in the stern and is attached by a hinged connection. ATBs generally utilize Intercon and Bludworth connecting systems, aTBs are generally staffed as a large tugboat, with between seven and nine crew members. The typical American ATB operating on the east coast customarily displays navigational lights of a towing vessel pushing ahead, compared to seagoing tugboats, harbour tugboats are generally smaller and their width-to-length ratio is often higher, due to the need for a lower draught. In smaller harbours these are also termed lunch bucket boats, because they are only manned when needed and only at a minimum. The number of tugboats in a harbour varies with the harbour infrastructure, things to take into consideration includes ships with/without bow thrusters and forces like wind, current and waves and types of ship. River tugs are also referred to as towboats or pushboats and their hull designs would make open ocean operation dangerous. River tugs usually do not have any significant hawser or winch and their hulls feature a flat front or bow to line up with the rectangular stern of the barge, often with large pushing knees. Tugboat engines typically produce 500 to 2,500 kW, for safety, tugboats engines often feature two of each critical part for redundancy. A tugboats power is stated by its engines horsepower and its overall bollard pull. The largest commercial harbour tugboats in the 2000s-2010s, used for towing container ships or similar, had around 60-65 tons of bollard pull, Tugboats are highly maneuverable, and various propulsion systems have been developed to increase maneuverability and increase safety
11.
Fishing vessel
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A fishing vessel is a boat or ship used to catch fish in the sea, or on a lake or river. Many different kinds of vessels are used in commercial, artisanal and recreational fishing, according to the FAO, there are currently four million commercial fishing vessels. About 1.3 million of these are decked vessels with enclosed areas, nearly all of these decked vessels are mechanised, and 40,000 of them are over 100 tons. At the other extreme, two-thirds of the boats are traditional craft of various types, powered only by sail. These boats are used by artisan fishers and it is difficult to estimate the number of recreational fishing boats. They range in size from small dinghies to large charter cruisers, prior to the 1950s there was little standardisation of fishing boats. Designs could vary between ports and boatyards, traditionally boats were built of wood, but wood is not often used now because it has higher maintenance costs and lower durability. Fibreglass is used increasingly in smaller fishing vessels up to 25 metres, early fishing vessels included rafts, dugout canoes, and boats constructed from a frame covered with hide or tree bark, along the lines of a coracle. The oldest boats found by excavation are dugout canoes dating back to the Neolithic Period around 7. These canoes were often cut from coniferous tree logs, using stone tools. A 7000-year-old seagoing boat made from reeds and tar has been found in Kuwait and these early vessels had limited capability, they could float and move on water, but were not suitable for use any great distance from the shoreline. They were used mainly for fishing and hunting, the development of fishing boats took place in parallel with the development of boats built for trade and war. Early navigators began to use skins or woven fabrics for sails. Affixed to a pole set upright in the boat, these sails gave early boats more range, Egyptians were building long narrow boats powered by many oarsmen. Over the next 1,000 years, they made a series of advances in boat design. They developed cotton-made sails to help their boats go faster with less work, then they built boats large enough to cross the oceans. These boats had sails and oarsmen, and were used for travel, by 3000 BC, the Egyptians knew how to assemble planks of wood into a ship hull. They used woven straps to lash planks together, and reeds or grass stuffed between the planks to seal the seams
12.
Boat
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A boat is a watercraft of a large range of sizes designed to float, plane, work or travel on water. Small boats are found on inland waterways or in protected coastal areas. However, boats such as the whaleboat were designed for operation from a ship in an offshore environment, in naval terms, a boat is a vessel small enough to be carried aboard another vessel. Another less restrictive definition is a vessel that can be lifted out of the water, some definitions do not make a distinction in size, as bulk freighters 1,000 feet long on the Great Lakes are called oreboats. For reasons of tradition, submarines are usually referred to as boats rather than ships, regardless of their size. Ships are generally distinguished from boats based on their size, shape. Boats have a variety of shapes, sizes and construction methods due to their intended purpose. Canoe-type boats have used since prehistoric times and various versions are used throughout the world for transportation. Fishing boats vary widely in style partly to local conditions. Pleasure boats include ski boats, pontoon boats, and sailboats, house boats may be used for vacationing or long-term housing. Small boats can provide transport or convey cargo to and from large ships, lifeboats have rescue and safety functions. Boats can be powered by power, wind power and motor power. Dugouts are the oldest type of boats found by archaeologists, the earliest boats are thought to have been logboats, and the oldest boats found by archaeological excavation date from around 7, 000–10,000 years ago. The oldest recovered boat in the world is the Pesse canoe and this canoe is exhibited in the Drents Museum in Assen, Netherlands. Other very old dugout boats have also been recovered, rafts have operated for at least 8,000 years. A7, 000-year-old seagoing reed boat has been found in Kuwait, boats were used between 4000 and 3000 BC in Sumer, ancient Egypt and in the Indian Ocean. Boats played an important role in the commerce between the Indus Valley Civilization and Mesopotamia, evidence of varying models of boats has also been discovered at various Indus Valley archaeological sites. Uru craft originate in Beypore, a village in south Calicut, Kerala and this type of mammoth wooden ship was constructed using teak, without any iron, and had a transport capacity of 400 tonnes
13.
Coin
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A coin is a small, flat, round piece of metal or plastic used primarily as a medium of exchange or legal tender. They are standardized in weight, and produced in quantities at a mint in order to facilitate trade. They are most often issued by a government, Coins are usually metal or alloy, or sometimes made of synthetic materials. Coins made of metal are stored in large quantities as bullion coins. Other coins are used as money in transactions, circulating alongside banknotes. Usually the highest value coin in circulation is less than the lowest-value note. In the last hundred years, the value of circulation coins has occasionally been lower than the value of the metal they contain. Exceptions to the rule of face value being higher than content value also occur for some bullion coins made of copper, silver, or gold, while the Eagle, Maple Leaf, and Sovereign coins have nominal face values, the Krugerrand does not. The first coins were developed independently in Iron Age Anatolia and Archaic Greece, India, Coins spread rapidly in the 6th and 5th centuries BCE, throughout Greece and Persia, and further to the Balkans. Standardized Roman currency was used throughout the Roman Empire, important Roman gold and silver coins were continued into the Middle Ages. Fiat money first arose in medieval China, with the paper money. Early paper money was introduced in Europe in the later Middle Ages, the penny was minted as a silver coin until the 17th century. The first circulating United States coins were cents, produced in 1793, Coins were an evolution of currency systems of the Late Bronze Age, where standard-sized ingots, and tokens such as knife money, were used to store and transfer value. In the late Chinese Bronze Age, standardized cast tokens were made and these were replicas in bronze of earlier Chinese currency, cowrie shells, so they were named Bronze Shell. According to Aristotle and Pollux, the first issuer of coins was Hermodike of Kyme The earliest coins are associated with Iron Age Anatolia. Early electrum coins were not standardized in weight, and in their earliest stage may have been ritual objects, such as badges or medals, issued by priests. The first Lydian coins were made of electrum, a naturally occurring alloy of silver, most of the early Lydian coins include no writing, only an image of a symbolic animal. Anatolian Artemis was the Πὀτνια Θηρῶν, whose symbol was the stag, a small percentage of early Lydian/Greek coins have a legend
14.
Silver
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Silver is a metallic element with symbol Ag and atomic number 47. The symbol Ag stems from Latin argentum, derived from the Greek ὰργὀς, a soft, white, lustrous transition metal, it exhibits the highest electrical conductivity, thermal conductivity, and reflectivity of any metal. The metal is found in the Earths crust in the pure, free form, as an alloy with gold and other metals. Most silver is produced as a byproduct of copper, gold, lead, Silver is more abundant than gold, but it is much less abundant as a native metal. Its purity is measured on a per mille basis, a 94%-pure alloy is described as 0.940 fine. As one of the seven metals of antiquity, silver has had a role in most human cultures. Silver has long valued as a precious metal. Silver metal is used in many premodern monetary systems in bullion coins, Silver is used in numerous applications other than currency, such as solar panels, water filtration, jewelry, ornaments, high-value tableware and utensils, and as an investment medium. Silver is used industrially in electrical contacts and conductors, in specialized mirrors, window coatings, Silver compounds are used in photographic film and X-rays. Dilute silver nitrate solutions and other compounds are used as disinfectants and microbiocides, added to bandages and wound-dressings, catheters. Silver is similar in its physical and chemical properties to its two neighbours in group 11 of the periodic table, copper and gold. This distinctive electron configuration, with an electron in the highest occupied s subshell over a filled d subshell. Silver is a soft, ductile and malleable transition metal. Silver crystallizes in a cubic lattice with bulk coordination number 12. Unlike metals with incomplete d-shells, metallic bonds in silver are lacking a covalent character and are relatively weak and this observation explains the low hardness and high ductility of single crystals of silver. Silver has a brilliant white metallic luster that can take a polish. Protected silver has greater optical reflectivity than aluminium at all wavelengths longer than ~450 nm, at wavelengths shorter than 450 nm, silvers reflectivity is inferior to that of aluminium and drops to zero near 310 nm. The electrical conductivity of silver is the greatest of all metals, greater even than copper, during World War II in the US,13540 tons of silver were used in electromagnets for enriching uranium, mainly because of the wartime shortage of copper
15.
French language
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French is a Romance language of the Indo-European family. It descended from the Vulgar Latin of the Roman Empire, as did all Romance languages, French has evolved from Gallo-Romance, the spoken Latin in Gaul, and more specifically in Northern Gaul. Its closest relatives are the other langues doïl—languages historically spoken in northern France and in southern Belgium, French was also influenced by native Celtic languages of Northern Roman Gaul like Gallia Belgica and by the Frankish language of the post-Roman Frankish invaders. Today, owing to Frances past overseas expansion, there are numerous French-based creole languages, a French-speaking person or nation may be referred to as Francophone in both English and French. French is a language in 29 countries, most of which are members of la francophonie. As of 2015, 40% of the population is in Europe, 35% in sub-Saharan Africa, 15% in North Africa and the Middle East, 8% in the Americas. French is the fourth-most widely spoken mother tongue in the European Union, 1/5 of Europeans who do not have French as a mother tongue speak French as a second language. As a result of French and Belgian colonialism from the 17th and 18th century onward, French was introduced to new territories in the Americas, Africa, most second-language speakers reside in Francophone Africa, in particular Gabon, Algeria, Mauritius, Senegal and Ivory Coast. In 2015, French was estimated to have 77 to 110 million native speakers, approximately 274 million people are able to speak the language. The Organisation internationale de la Francophonie estimates 700 million by 2050, in 2011, Bloomberg Businessweek ranked French the third most useful language for business, after English and Standard Mandarin Chinese. Under the Constitution of France, French has been the language of the Republic since 1992. France mandates the use of French in official government publications, public education except in specific cases, French is one of the four official languages of Switzerland and is spoken in the western part of Switzerland called Romandie, of which Geneva is the largest city. French is the language of about 23% of the Swiss population. French is also a language of Luxembourg, Monaco, and Aosta Valley, while French dialects remain spoken by minorities on the Channel Islands. A plurality of the worlds French-speaking population lives in Africa and this number does not include the people living in non-Francophone African countries who have learned French as a foreign language. Due to the rise of French in Africa, the total French-speaking population worldwide is expected to reach 700 million people in 2050, French is the fastest growing language on the continent. French is mostly a language in Africa, but it has become a first language in some urban areas, such as the region of Abidjan, Ivory Coast and in Libreville. There is not a single African French, but multiple forms that diverged through contact with various indigenous African languages, sub-Saharan Africa is the region where the French language is most likely to expand, because of the expansion of education and rapid population growth
16.
Spanish language
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Spanish —also called Castilian —is a Romance language that originated in the Castile region of Spain, with hundreds of millions of native speakers around the world. It is usually considered the worlds second-most spoken native language after Mandarin Chinese and it is one of the few languages to use inverted question and exclamation marks. Spanish is a part of the Ibero-Romance group of languages, which evolved from several dialects of Vulgar Latin in Iberia after the collapse of the Western Roman Empire in the 5th century. Beginning in the early 16th century, Spanish was taken to the colonies of the Spanish Empire, most notably to the Americas, as well as territories in Africa, Oceania, around 75% of modern Spanish is derived from Latin. Greek has also contributed substantially to Spanish vocabulary, especially through Latin, Spanish vocabulary has been in contact from an early date with Arabic, having developed during the Al-Andalus era in the Iberian Peninsula. With around 8% of its vocabulary being Arabic in origin, this language is the second most important influence after Latin and it has also been influenced by Basque as well as by neighboring Ibero-Romance languages. It also adopted words from languages such as Gothic language from the Visigoths in which many Spanish names and surnames have a Visigothic origin. Spanish is one of the six languages of the United Nations. It is the language in the world by the number of people who speak it as a mother tongue, after Mandarin Chinese. It is estimated more than 437 million people speak Spanish as a native language. Spanish is the official or national language in Spain, Equatorial Guinea, speakers in the Americas total some 418 million. In the European Union, Spanish is the tongue of 8% of the population. Spanish is the most popular second language learned in the United States, in 2011 it was estimated by the American Community Survey that of the 55 million Hispanic United States residents who are five years of age and over,38 million speak Spanish at home. The Spanish Constitution of 1978 uses the term castellano to define the language of the whole Spanish State in contrast to las demás lenguas españolas. Article III reads as follows, El castellano es la lengua española oficial del Estado, las demás lenguas españolas serán también oficiales en las respectivas Comunidades Autónomas. Castilian is the official Spanish language of the State, the other Spanish languages as well shall be official in their respective Autonomous Communities. The Spanish Royal Academy, on the hand, currently uses the term español in its publications. Two etymologies for español have been suggested, the Spanish Royal Academy Dictionary derives the term from the Provençal word espaignol, and that in turn from the Medieval Latin word Hispaniolus, from—or pertaining to—Hispania
17.
Corrosion
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Corrosion is a natural process, which converts a refined metal to a more chemically-stable form, such as its oxide, hydroxide, or sulfide. It is the destruction of materials by chemical and/or electrochemical reaction with their environment. Corrosion engineering is the dedicated to controlling and stopping corrosion. In the most common use of the word, this means electrochemical oxidation of metal in reaction with an oxidant such as oxygen or sulfur, rusting, the formation of iron oxides, is a well-known example of electrochemical corrosion. This type of damage typically produces oxide or salt of the original metal, corrosion can also occur in materials other than metals, such as ceramics or polymers, although in this context, the term degradation is more common. Corrosion degrades the useful properties of materials and structures including strength, appearance and permeability to liquids, many structural alloys corrode merely from exposure to moisture in air, but the process can be strongly affected by exposure to certain substances. Corrosion can be concentrated locally to form a pit or crack, because corrosion is a diffusion-controlled process, it occurs on exposed surfaces. As a result, methods to reduce the activity of the surface, such as passivation and chromate conversion. However, some corrosion mechanisms are less visible and less predictable, in a galvanic couple, the more active metal corrodes at an accelerated rate and the more noble metal corrodes at a slower rate. When immersed separately, each metal corrodes at its own rate, what type of metal to use is readily determined by following the galvanic series. For example, zinc is used as a sacrificial anode for steel structures. Galvanic corrosion is of major interest to the industry and also anywhere water contacts pipes or metal structures. Factors such as size of anode, types of metal. The surface area ratio of the anode and cathode directly affects the corrosion rates of the materials, galvanic corrosion is often prevented by the use of sacrificial anodes. In any given environment, one metal will be more noble or more active than others. Two metals in electrical contact share the same electrons, so that the tug-of-war at each surface is analogous to competition for free electrons between the two materials. Using the electrolyte as a host for the flow of ions in the same direction, the resulting mass flow or electric current can be measured to establish a hierarchy of materials in the medium of interest. This hierarchy is called a series and is useful in predicting and understanding corrosion
18.
Biofouling
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Biofouling or biological fouling is the accumulation of microorganisms, plants, algae, or animals on wetted surfaces. Such accumulation is referred to as epibiosis when the host surface is another organism, antifouling is the ability of specifically designed materials and coatings to remove or prevent biofouling by any number of organisms on wetted surfaces. Specifically, the buildup of biofouling on marine vessels poses a significant problem, in some instances, the hull structure and propulsion systems can be damaged. The accumulation of biofoulers on hulls can increase both the volume of a vessel and the hydrodynamic friction, leading to increased drag of up to 60%. The drag increase has been seen to decrease speeds by up to 10%, with fuel typically comprising up to half of marine transport costs, antifouling methods are estimated to save the shipping industry around $60 billion per year. Increased fuel use due to biofouling contributes to environmental effects and is predicted to increase emissions of carbon dioxide. A variety of antifouling methods have historically been implemented to combat biofouling, recently, scientists have begun researching antifouling methods inspired by living organisms. This type of imitation is known as biomimicry. The variety among biofouling organisms is highly diverse, and extends far beyond attachment of barnacles, according to some estimates, over 1700 species comprising over 4000 organisms are responsible for biofouling. Biofouling is divided into microfouling — biofilm formation and bacterial adhesion —, due to the distinct chemistry and biology that determine what prevents them from settling, organisms are also classified as hard- or soft-fouling types. Calcareous fouling organisms include barnacles, encrusting bryozoans, mollusks, polychaete and other tube worms, examples of non-calcareous fouling organisms are seaweed, hydroids, algae and biofilm slime. Together, these form a fouling community. Marine fouling is typically described as following four stages of ecosystem development, the chemistry of biofilm formation describes the initial steps prior to colonization. Within the first minute the van der Waals interaction causes the surface to be covered with a conditioning film of organic polymers. In the next 24 hours, this allows the process of bacterial adhesion to occur. By the end of the first week, the nutrients and ease of attachment into the biofilm allow secondary colonizers of spores of macroalgae. Within 2 to 3 weeks, the tertiary colonizers- the macrofoulers- have attached and these include tunicates, mollusks and sessile Cnidarians. Governments and industry more than US$5.7 billion annually to prevent
19.
Shipbuilding
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Shipbuilding is the construction of ships and other floating vessels. It normally takes place in a facility known as a shipyard. Shipbuilders, also called shipwrights, follow a specialized occupation that traces its roots to before recorded history, Shipbuilding and ship repairs, both commercial and military, are referred to as naval engineering. The construction of boats is an activity called boat building. The dismantling of ships is called ship breaking, the ancestors of Australian Aborigines and New Guineans also went across the Lombok Strait to Sahul by boat over 50,000 years ago. Evidence from Ancient Egypt shows that the early Egyptians knew how to assemble planks of wood into a ship hull as early as 3000 BC, the Archaeological Institute of America reports that some of the oldest ships yet unearthed are known as the Abydos boats. These are a group of 14 ships discovered in Abydos that were constructed of wooden planks which were sewn together, the ship dating to 3000 BC was about 25 m,75 feet long and is now thought to perhaps have belonged to an earlier pharaoh. According to professor OConnor, the 5, 000-year-old ship may have belonged to Pharaoh Aha. Early Egyptians also knew how to assemble planks of wood with treenails to fasten them together, early Egyptians also knew how to fasten the planks of this ship together with mortise and tenon joints. The oldest known tidal dock in the world was built around 2500 BC during the Harappan civilisation at Lothal near the present day Mangrol harbour on the Gujarat coast in India, other ports were probably at Balakot and Dwarka. However, it is probable that many small-scale ports, and not massive ports, were used for the Harappan maritime trade, ships from the harbour at these ancient port cities established trade with Mesopotamia. Shipbuilding and boatmaking may have been prosperous industries in ancient India, native labourers may have manufactured the flotilla of boats used by Alexander the Great to navigate across the Hydaspes and even the Indus, under Nearchos. The Indians also exported teak for shipbuilding to ancient Persia, other references to Indian timber used for shipbuilding is noted in the works of Ibn Jubayr. The ships of Ancient Egypts Eighteenth Dynasty were typically about 25 meters in length and they mounted a single square sail on a yard, with an additional spar along the bottom of the sail. These ships could also be oar propelled, the ocean and sea going ships of Ancient Egypt were constructed with cedar wood, most likely hailing from Lebanon. The ships of Phoenicia seem to have been of a similar design, the naval history of China stems back to the Spring and Autumn period of the ancient Chinese Zhou Dynasty. The Chinese built large rectangular barges known as ships, which were essentially floating fortresses complete with multiple decks with guarded ramparts. There is considerable knowledge regarding shipbuilding and seafaring in the ancient Mediterranean and this was dually met with the introduction of the Han Dynasty junk ship design in the same century
20.
Desalination plants
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Desalination is a process that extracts minerals from saline water. More generally, desalination refers to the removal of salts and minerals from a substance, as in soil desalination. Saltwater is desalinated to produce water suitable for consumption or irrigation. One by-product of desalination is salt, Desalination is used on many seagoing ships and submarines. Most of the modern interest in desalination is focused on cost-effective provision of water for human use. Along with recycled wastewater, it is one of the few rainfall-independent water sources, due to its energy consumption, desalinating sea water is generally more costly than fresh water from rivers or groundwater, water recycling and water conservation. However, these alternatives are not always available and depletion of reserves is a problem worldwide. Currently, approximately 1% of the population is dependent on desalinated water to meet daily needs. Desalination is particularly relevant in dry countries such as Australia, which traditionally have relied on collecting rainfall behind dams for water and this number increased from 78.4 million cubic meters in 2013, a 10. 71% increase in 2 years. Kuwait produces a higher proportion of its water than any other country, the traditional process used in these operations is vacuum distillation—essentially boiling it to leave impurities behind. In desalination, atmospheric pressure is reduced, thus lowering the temperature needed. Liquids boil when the pressure equals the ambient pressure and vapor pressure increases with temperature. Thus, because of the temperature, low-temperature waste heat from electrical power generation or industrial processes can be employed. Water is evaporated and separated from sea water through multi-stage flash distillation, each subsequent flash process utilizes energy released from the condensation of the water vapor from the previous step. Multiple effect distillation works through a series of steps called “effects”, incoming water is sprayed onto vertically or, more commonly, horizontally oriented pipes which are then heated to generate steam. The steam is used to heat the next batch of incoming sea water. To increase efficiency, the used to heat the sea water can be taken from nearby power plants. Although this method is the most thermodynamically efficient, a few limitations exist such as a max temperature, vapor compression distillation involves using either a mechanical compressor or a jet stream to compress the vapor present above the liquid
21.
Offshore drilling
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Offshore drilling is a mechanical process where a wellbore is drilled below the seabed. It is typically carried out in order to explore for and subsequently extract petroleum which lies in rock formations beneath the seabed. Most commonly, the term is used to describe drilling activities on the shelf, though the term can also be applied to drilling in lakes, inshore waters. Offshore drilling presents environmental challenges, both from the hydrocarbons and the materials used during the drilling operation. Controversies include the ongoing US offshore drilling debate, there are many different types of facilities from which offshore drilling operations take place. These are capable of operating in depths up to 3,000 metres. Around 1891, the first submerged oil wells were drilled from platforms built on piles in the waters of the Grand Lake St. Marys in Ohio. The wells were developed by local companies such as Bryson, Riley Oil, German-American. Around 1896, the first submerged oil wells in salt water were drilled in the portion of the Summerland field extending under the Santa Barbara Channel in California, the wells were drilled from piers extending from land out into the channel. Other notable early submerged drilling activities occurred on the Canadian side of Lake Erie in the 1900s, shortly thereafter wells were drilled in tidal zones along the Texas and Louisiana gulf coast. The Goose Creek Oil Field near Baytown, Texas is one such example, in the 1920s drilling activities occurred from concrete platforms in Venezuelas Lake Maracaibo. One of the oldest subsea wells is the Bibi Eibat well, the well was located on an artificial island in a shallow portion of the Caspian Sea. In the early 1930s, the Texas Co. later Texaco developed the first mobile steel barges for drilling in the coastal areas of the Gulf of Mexico. In 1937, Pure Oil and its partner Superior Oil used a platform to develop a field 1 mile offshore of Calcasieu Parish. In 1938, Humble Oil built a wooden trestle with railway tracks into the sea at McFadden Beach on the Gulf of Mexico. In 1946, Magnolia Petroleum drilled at a site 18 miles off the coast, erecting a platform in 18 feet of water off St. Mary Parish, Louisiana. In early 1947, Superior Oil erected a drilling and production platform in 20 feet of water some 18 miles off Vermilion Parish, in any case, that made Kerr-McGees well the first oil discovery drilled out of sight of land. The first semi-submersible resulted from an observation in 1961
22.
Floating production storage and offloading
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A Floating Production, Storage and Offloading unit is a floating vessel used by the offshore oil and gas industry for the production and processing of hydrocarbons, and for the storage of oil. FPSOs are preferred in frontier offshore regions as they are easy to install, FPSOs can be a conversion of an oil tanker or can be a vessel built specially for the application. A vessel used only to store oil is referred to as a Floating Storage, emerging new type of FLNG facilities will be used. Unlike FPSOs apart of gas production, storage and offloading, they also allow full scale deep processing, same as onshore LNG plant has to offer. First 3 FLNGs are under construction, Prelude FLNG, PFLNG1, oil has been produced from offshore locations since the late 1940s. Originally, all oil platforms sat on the seabed, but as exploration moved to deeper waters and more distant locations in the 1970s, the first oil FPSO was the Shell Castellon, built in Spain in 1977. Today, over 270 vessels are deployed worldwide as oil FPSOs, on July 29,2009, Shell and Samsung announced an agreement to build up to 10 LNG FPSOs, at same Samsung Yard Flex LNG appeared to construct smaller units. Royal Dutch Shell, LNG FPSO, Samsung Heavy Industries at a cost of $12 Billion, in June 2012, Petronas made a contract of procurement engineering, construction, installation and commissioning, a project with the Technip and DSME consortium. The unit is destined for the Kanowit gas field off Sarawak and it is expected to be the Worlds First Floating Liquefaction Unit in operation when completed in 2015. Oil produced from offshore production platforms can be transported to the mainland either by pipeline or by tanker, Floating production, storage and offloading vessels are particularly effective in remote or deep water locations, where seabed pipelines are not cost effective. FPSOs eliminate the need to lay expensive long-distance pipelines from the facility to an onshore terminal. This can provide an attractive solution for smaller oil fields. Furthermore, once the field is depleted, the FPSO can be moved to a new location, a Floating Storage and Offloading unit is essentially a simplified FPSO, without the capability for oil or gas processing. Most FSOs are converted single hull supertankers, an example is Knock Nevis, ex Seawise Giant, which for many years was the worlds largest ship. It has been converted to an FSO for use offshore, FSO, Floating Storage and Offloading FPSO, Floating Production, Storage and Offloading FDPSO, Floating, Drilling and Production, Storage and Offloading FSRU, Floating Storage Regasification Unit. In addition to the records already mentioned, a few more are added in this section. The FPSO operating in the deepest waters is the FPSO BW Pioneer, built, the FPSO is moored at a depth of 2,600 m in Block 249 Walker Ridge in the US Gulf of Mexico and is rated for 80,000 bbl/d. The EPCI contract was awarded in October 2007 and production started in early 2012, the FPSO conversion was carried out at MMHE Shipyard Pasir Gudang in Malaysia, while the topsides were fabricated in modules at various international vendor locations
23.
Electricity generation
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Electricity generation is the process of generating electric power from sources of primary energy. For electric utilities, it is the first process in the delivery of electricity to consumers, the other processes as transmission, distribution, energy storage and recovery using pumped-storage methods are normally carried out by the electric power industry. Other energy sources include solar photovoltaics and geothermal power, the fundamental principles of electricity generation were discovered during the 1820s and early 1830s by the British scientist Michael Faraday. This method is used today, electricity is generated by the movement of a loop of wire. Central power stations became practical with the development of alternating current power transmission, using power transformers to transmit power at high voltage. Electricity has been generated at central stations since 1882, the use of power-lines and power-poles have been significantly important in the distribution of electricity. There are seven fundamental methods of transforming other forms of energy into electrical energy. Static electricity, form the physical separation and transport of charge and it was the first form discovered and investigated, and the electrostatic generator is still used even in modern devices such as the Van de Graaff generator and MHD generators. In Electromagnetic induction, a generator, dynamo or alternator transforms kinetic energy into electricity. This is the most used form for generating electricity and is based on Faradays law and it can be experimented by rotating a magnet within closed loops of a conducting material. Almost all commercial electrical generation is done using electromagnetic induction, in mechanical energy forces a generator to rotate. Almost all electrical power on Earth is generated with a turbine, driven by wind, water, there are many different methods of developing mechanical energy, including heat engines, hydro, wind and tidal power. Most electric generation is driven by heat engines, the combustion of fossil fuels supplies most of the heat to these engines, with a significant fraction from nuclear fission and some from renewable sources. The modern steam turbine currently generates about 80% of the power in the world using a variety of heat sources. Power sources include, Steam Water is boiled by coal burned in a power plant. Nuclear fission heat created in a nuclear reactor creates steam, less than 15% of electricity is generated this way. Natural gas, turbines are directly by gases produced by combustion. Combined cycle are driven by steam and natural gas
24.
Electrical resistivity and conductivity
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Electrical resistivity is an intrinsic property that quantifies how strongly a given material opposes the flow of electric current. A low resistivity indicates a material that allows the flow of electric current. Resistivity is commonly represented by the Greek letter ρ, the SI unit of electrical resistivity is the ohm-metre. Electrical conductivity or specific conductance is the reciprocal of electrical resistivity and it is commonly represented by the Greek letter σ, but κ or γ are also occasionally used. Its SI unit is siemens per metre and CGSE unit is reciprocal second, many resistors and conductors have a uniform cross section with a uniform flow of electric current, and are made of one material. All copper wires, irrespective of their shape and size, have approximately the same resistivity, every material has its own characteristic resistivity – for example, resistivity of rubber is far larger than coppers. If the pipes are the size and shape, the pipe full of sand has higher resistance to flow. Resistance, however, is not solely determined by the presence or absence of sand and it also depends on the length and width of the pipe, short or wide pipes have lower resistance than narrow or long pipes. The above equation can be transposed to get Pouillets law, R = ρ ℓ A, the resistance of a given material increases with length, but decreases with increasing cross-sectional area. From the above equations, resistivity has the SI unit ohm metre, the formula R = ρ ℓ / A can be used to intuitively understand the meaning of a resistivity value. For example, if A = 7000100000000000000♠1 m2 ℓ = 7000100000000000000♠1 m, Conductivity, σ, is defined as the inverse of resistivity, σ =1 ρ. Conductivity has SI units of siemens per metre, the above definition was specific to resistors or conductors with a uniform cross-section, where current flows uniformly through them. A more basic and general definition starts from the fact that a field inside a material makes electric current flow. Conductivity is the inverse, σ =1 ρ = J E, for example, rubber is a material with large ρ and small σ—because even a very large electric field in rubber makes almost no current flow through it. On the other hand, copper is a material with small ρ, according to elementary quantum mechanics, electrons in an atom do not take on arbitrary energy values. Rather, electrons only occupy discrete energy levels in an atom or crystal. When a large number of such allowed energy levels are spaced close together —i. e. have similar energies— we can talk about these energy levels together as an energy band. There can be many such bands in a material, depending on the atomic number
25.
Ductility
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In materials science, ductility is a solid materials ability to deform under tensile stress, this is often characterized by the materials ability to be stretched into a wire. Malleability, a property, is a materials ability to deform under compressive stress. Both of these properties are aspects of plasticity, the extent to which a solid material can be plastically deformed without fracture. Also, these properties are dependent on temperature and pressure. Ductility and malleability are not always coextensive – for instance, while gold has high ductility and malleability, lead has low ductility, the word ductility is sometimes used to encompass both types of plasticity. Ductility is especially important in metalworking, as materials that crack, break or shatter under stress cannot be manipulated using metal-forming processes such as hammering, rolling, malleable materials can be formed cold using stamping or pressing, whereas brittle materials may be cast or thermoformed. High degrees of ductility occur due to bonds, which are found predominantly in metals. In metallic bonds valence shell electrons are delocalized and shared between many atoms, the delocalized electrons allow metal atoms to slide past one another without being subjected to strong repulsive forces that would cause other materials to shatter. Ductility can be quantified by the fracture strain ε f, which is the strain at which a test specimen fractures during a uniaxial tensile test. Another commonly used measure is the reduction of area at fracture q, the ductility of steel varies depending on the alloying constituents. Increasing levels of carbon decrease ductility, many plastics and amorphous solids, such as Play-Doh, are also malleable. The most ductile metal is platinum and the most malleable metal is gold, DBTT is important since, once a material is cooled below the DBTT, it has a much greater tendency to shatter on impact instead of bending or deforming. For example, zamak 3 exhibits good ductility at room temperature, DBTT is a very important consideration in selecting materials that are subjected to mechanical stresses. A similar phenomenon, the transition temperature, occurs with glasses and polymers. In some materials the transition is sharper than others and typically requires a temperature-sensitive deformation mechanism and this can be problematic for steels with a high ferrite content. This famously resulted in serious hull cracking in Liberty ships in colder waters during World War II, DBTT can also be influenced by external factors such as neutron radiation, which leads to an increase in internal lattice defects and a corresponding decrease in ductility and increase in DBTT. The most accurate method of measuring the DBTT of a material is by fracture testing, typically four point bend testing at a range of temperatures is performed on pre-cracked bars of polished material. For experiments conducted at higher temperatures, dislocation activity increases, the temperature at which this occurs is the ductile–brittle transition temperature
26.
Recycling
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Recycling is the process of converting waste materials into new materials and objects. It is an alternative to conventional waste disposal that can save material, Recycling can prevent the waste of potentially useful materials and reduce the consumption of fresh raw materials, thereby reducing, energy usage, air pollution, and water pollution. Recycling is a key component of waste reduction and is the third component of the Reduce, Reuse. There are some ISO standards related to recycling such as ISO15270,2008 for plastics waste, recyclable materials include many kinds of glass, paper, and cardboard, metal, plastic, tires, textiles, and electronics. The composting or other reuse of biodegradable waste—such as food or garden waste—is also considered recycling, materials to be recycled are either brought to a collection centre or picked up from the curbside, then sorted, cleaned, and reprocessed into new materials destined for manufacturing. However, this is difficult or too expensive, so recycling of many products or materials involves their reuse in producing different materials instead. Another form of recycling is the salvage of materials from complex products, either due to their intrinsic value. Recycling has been a practice for most of human history. In pre-industrial times, there is evidence of bronze and other metals being collected in Europe. Paper recycling was first recorded in 1031 when Japanese shops sold repulped paper, in Britain dust and ash from wood and coal fires was collected by dustmen and downcycled as a base material used in brick making. In 1813, Benjamin Law developed the process of turning rags into shoddy and mungo wool in Batley and this material combined recycled fibers with virgin wool. The West Yorkshire shoddy industry in such as Batley and Dewsbury lasted from the early 19th century to at least 1914. Industrialization spurred demand for materials, aside from rags, ferrous scrap metals were coveted as they were cheaper to acquire than virgin ore. Railroads both purchased and sold scrap metal in the 19th century, and the steel and automobile industries purchased scrap in the early 20th century. Many secondary goods were collected, processed and sold by peddlers who scoured dumps and city streets for discarded machinery, pots, pans, and other sources of metal. By World War I, thousands of such peddlers roamed the streets of American cities, beverage bottles were recycled with a refundable deposit at some drink manufacturers in Great Britain and Ireland around 1800, notably Schweppes. New chemical industries created in the late 19th century both invented new materials (e. g. Bakelite and promised to transform valueless into valuable materials, new and better paths are opened to reach the goals desired. Recycling was a highlight throughout World War II, during the war, financial constraints and significant material shortages due to war efforts made it necessary for countries to reuse goods and recycle materials
27.
Belgians
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Belgians are the citizens of the Kingdom of Belgium, a federal state in Western Europe. There is also a substantial Belgian diaspora, settling primarily the United States, Canada, Belgians are a relatively new people. The 1830 revolution led to the establishment of an independent country under a provisional government, the Belgian people are descendants of the Celtic Belgae and Germanic peoples such as the Frisians, Franks, and the Saxons. The Latin name was revived in 1790 by the short-lived United Belgian States which was created after a revolution against Austrian rule took place in 1789, from the sixteenth century, the The Low Countries or The Netherlands, were referred to as Belgica in Latin. Belgians are primarily a nationality or citizen group, by jus soli, also known as birthright citizenship, since many Belgians are at least bilingual, or even trilingual, it is common for business, social and family networks to include members of the various ethnic groups composing Belgium. The Brussels-Capital Region occupies a unique political and cultural position since geographically and linguistically it is an enclave within the unilingual Flemish Region. Since the independence of Belgium in 1830, the title of the Belgian head of state is the King of the Belgians rather than the King of Belgium. Within Belgium the Flemish, about 60% of the population, form a clearly distinguishable group, set apart by their language, however, the popular perception of being a single polity varies greatly, depending on subject matter, locality and personal background. Generally, Flemings will seldom identify themselves as being Dutch and vice versa, Walloons are a French-speaking people who live in Belgium, principally in Wallonia. Walloons are a community within Belgium, important historical and anthropological criteria bind Walloons to the French people. More generally, the term refers to the inhabitants of the Walloon Region. They may speak languages such as Walloon. Though roughly three-quarters of Belgiums French speakers live in Wallonia, it is important to note that French-speaking residents of Brussels tend not to identify as Walloons, the German-speaking Community of Belgium is one of the three constitutionally recognized federal communities of Belgium. Bordering the Netherlands, Germany and Luxembourg, the area has its own parliament and government at Eupen, the German-speaking community is composed of the German-speaking parts of the lands that were annexed in 1920 from Germany. However, in these localities, the German language is endangered due to the adoption of French. Roman Catholicism has traditionally been Belgiums majority religion with approximately 65% of the Belgians declaring themselves to be Catholics, however, by 2004, nationwide Sunday church attendance was only about 4 to 8%. Belgium had a population of 10,839,905 people on 1 January 2010, between 1990 and 2000 the increase was only 291,000. The population of Flanders, Wallonia and Brussels on 1 January 2010 was 6,251,983,3,498,384 and 1,089,538, list of Belgians Flemish people Walloons Belgian American Belgian Brazilian Flemish Canadian
28.
United States
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Forty-eight of the fifty states and the federal district are contiguous and located in North America between Canada and Mexico. The state of Alaska is in the northwest corner of North America, bordered by Canada to the east, the state of Hawaii is an archipelago in the mid-Pacific Ocean. The U. S. territories are scattered about the Pacific Ocean, the geography, climate and wildlife of the country are extremely diverse. At 3.8 million square miles and with over 324 million people, the United States is the worlds third- or fourth-largest country by area, third-largest by land area. It is one of the worlds most ethnically diverse and multicultural nations, paleo-Indians migrated from Asia to the North American mainland at least 15,000 years ago. European colonization began in the 16th century, the United States emerged from 13 British colonies along the East Coast. Numerous disputes between Great Britain and the following the Seven Years War led to the American Revolution. On July 4,1776, during the course of the American Revolutionary War, the war ended in 1783 with recognition of the independence of the United States by Great Britain, representing the first successful war of independence against a European power. The current constitution was adopted in 1788, after the Articles of Confederation, the first ten amendments, collectively named the Bill of Rights, were ratified in 1791 and designed to guarantee many fundamental civil liberties. During the second half of the 19th century, the American Civil War led to the end of slavery in the country. By the end of century, the United States extended into the Pacific Ocean. The Spanish–American War and World War I confirmed the status as a global military power. The end of the Cold War and the dissolution of the Soviet Union in 1991 left the United States as the sole superpower. The U. S. is a member of the United Nations, World Bank, International Monetary Fund, Organization of American States. The United States is a developed country, with the worlds largest economy by nominal GDP. It ranks highly in several measures of performance, including average wage, human development, per capita GDP. While the U. S. economy is considered post-industrial, characterized by the dominance of services and knowledge economy, the United States is a prominent political and cultural force internationally, and a leader in scientific research and technological innovations. In 1507, the German cartographer Martin Waldseemüller produced a map on which he named the lands of the Western Hemisphere America after the Italian explorer and cartographer Amerigo Vespucci
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Coins of the pound sterling
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The standard circulating coinage of the United Kingdom is denominated in pounds sterling, and, since the introduction of the two-pound coin in 1994, ranges in value from one penny to two pounds. Since decimalisation, on 15 February 1971, the pound has been divided into 100 pence, from the 16th century until decimalisation, the pound was divided into 20 shillings, each of 12 pence. British coins are minted by the Royal Mint in Llantrisant, Wales, the Royal Mint also commissions the coins designs. As of 30 March 2010, there were an estimated 28 billion coins circulating in the United Kingdom, the first decimal coins were circulated in 1968. These were the five pence and ten pence, and had values of one shilling, the decimal coins are minted in copper-plated steel, nickel-plated steel, cupro-nickel and nickel-brass. The two-pound coins, and, as of the 28th March 2017, all the circulating coins have an effigy of Queen Elizabeth II on the obverse, and various national and regional designs, and the denomination, on the reverse. The exception, the 2008 one-pound coin, depicts the shield of arms on the reverse. All current coins carry a Latin inscription whose full form is ELIZABETH II DEI GRATIA REGINA FIDEI DEFENSATRIX, meaning Elizabeth II, by the grace of God, Queen, in addition to the circulating coinage, the UK also mints commemorative decimal coins in the denomination of five pounds. Prior to decimalisation, the denomination was five shillings, that is. Crowns, therefore, had a value of 25p from decimalisation until 1981. Ceremonial Maundy money and bullion coinage of gold sovereigns, half sovereigns, some territories outside the United Kingdom, that use the pound sterling, produce their own coinage, with the same denominations and specifications as the UK coinage but local designs. In the years just prior to decimalisation, the circulating British coins were the half crown, the farthing had been withdrawn in 1960. There was also the Crown, which was legal tender but only minted on special occasions, all modern coins feature a profile of the current monarchs head. The direction in which they face changes with each successive monarch, for the Tudors and pre-Restoration Stuarts, both left and right-facing portrait images were minted within the reign of a single monarch. In the Middle Ages, portrait images tended to be full face, the English silver penny was derived from another silver coin, the sceat, of 20 troy grains weight, which was in general circulation in Europe during the Middle Ages. In the 12th century, Henry II established the silver standard for English coinage, of 92. 5% silver and 7. 5% copper. The coinage reform of 1816 set up a ratio and physical sizes for silver coins. Silver was eliminated from coins, except Maundy coins, in 1947, the history of the Royal Mint stretches back to AD886
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Three-cent piece (United States coin)
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The United States three cent piece was a unit of currency equaling 3⁄100 of a United States dollar. The mint produced two different three-cent coins for circulation, the three-cent silver and the three-cent nickel, additionally, a three-cent bronze coin was made as a pattern in 1863. During the period from 1865 to 1873, both coins were minted, albeit in small quantities for the silver three-cent piece. The three-cent coin has an unusual history and it was proposed in 1851 both as a result of the decrease in postage rates from five cents to three and to answer the need for a small-denomination, easy-to-handle coin. The three-cent silver featured a shield on a star on the obverse. The coin was composed of 75% silver and 25% copper to ensure that the coin would be considered real currency yet not worth melting down for the silver. The silver coins were known as fishscales, the term trimes is often used today for these coins, but that was first used by the director of the United States Mint at the time of their production. Starting in 1854, the three-cent silver had its silver metal content raised to 90% to encourage circulation, at the same time, its weight was reduced to 3/4 of a gram by reducing thickness. A final design occurred in 1859 because of striking problems, the number of lines bordering the star was reduced to one. The size of the date numerals also varied through the years, in 1851 only, the New Orleans Mint struck some of the silver three-cent coins. It was minted from 1851 to 1873 at the Philadelphia Mint, later years had very small mintages and the 1873 issue was in proof state only, commanding prices upwards of $400. However, an earlier-date silver three-cent piece can be bought in worn condition for a low price. The silver three-cent pieces can be purchased for around $25 if they are in decent shape and before 1862, the silver three-cent piece was discontinued by the Coinage Act of 1873. Civil War-era silver shortages led to widespread hoarding of all silver coins, various alternatives were tried, including encapsulated postage and privately issued coinage. The Treasury eventually settled on issuing fractional currency and these small denomination notes were never popular, as they were easy to lose and unwieldy in large amounts. The answer to this issue was reached in 1865 with the introduction of the three-cent nickel coin, composed of copper and nickel, the coin featured a Liberty head obverse and another Roman numeral III reverse. The three-cent nickel was never intended as a permanent issue, only as a stopgap measure until the wartime hoarding ceased, production began to taper off in the 1870s, but mintage of the denomination did not finally end until 1889. Another factor may have been that in 1883, the postage rate dropped to 2 cents
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Nickel (United States coin)
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A nickel, in American usage, is a five-cent coin struck by the United States Mint. Composed of 75% copper and 25% nickel, the piece has been issued since 1866 and its diameter is.835 inches and its thickness is.077 inches. The silver half dime, equal to five cents, had issued since the 1790s. The American Civil War caused economic hardship, driving gold and silver from circulation, in response, in place of low-value coins, the government at first issued paper currency. In 1865, Congress abolished the five-cent fractional currency note after Spencer M. Clark, head of the Currency Bureau, the initial design of the Shield nickel was struck from 1866 until 1883, then was replaced by the Liberty Head nickel. The Buffalo nickel was introduced in 1913 as part of a drive to increase the beauty of American coinage, in 1938, in 2004 and 2005, special designs in honor of the bicentennial of the Lewis and Clark Expedition were issued. In 2006, the Mint reverted to using Jefferson nickel designer Felix Schlags original reverse, although a new obverse, by Jamie Franki, was substituted. As of the end of FY2013, it cost more than nine cents to produce a nickel, the silver half disme was one of the denominations prescribed by the Mint Act of 1792, its weight and fineness were set by law. By legend, President Washington supplied silverware from his home, Mount Vernon, in 1793, the newly established Philadelphia Mint began striking cents and half cents. Coinage of precious metal was delayed, Congress required the assayer and chief coiner to each post a security bond of $10,000, a huge sum in 1793. In 1794, Congress lowered the chief coiners bond to $5,000, subsequently, silver coinage began that year. The half dime was struck to various designs by Mint Engraver Robert Scot from 1794 until 1805, though none were dated 1798,1799, in response, in 1804 the US stopped striking silver dollars, issuance of the half dime was discontinued from 1805 until 1829. Beginning in 1829, the silver five-cent piece was struck, beginning in 1837. In 1851, it ceased to be the smallest US silver coin as a three cent piece was issued by the Mint, although specie was hoarded or exported, the copper-nickel cent, then the only base metal denomination being struck, also vanished. In 1864, Congress began the process of restoring coins to circulation by abolishing the three-cent note and authorizing bronze cents and two-cent pieces, with low intrinsic values and these new coins initially proved popular, though the two-cent piece soon faded from circulation. On March 3,1865, Congress passed legislation authorizing the Mint to strike three-cent pieces of 75% copper, in 1864, Congress authorized a third series of fractional currency notes. Clark kept his job only because of the intervention of Treasury Secretary Salmon P. Chase. In his 1865 report, Pollock wrote, From this nickel alloy, a coin for the denomination of five cents, only until the resumption of specie payments
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Cladding (metalworking)
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Cladding is the bonding together of dissimilar metals. It is different from fusion welding or gluing as a method to fasten the metals together, cladding is often achieved by extruding two metals through a die as well as pressing or rolling sheets together under high pressure. The United States Mint uses cladding to manufacture coins from different metals and this allows a cheaper metal to be used as a filler. In roll bonding, two or more layers of different metals are cleaned and passed through a pair of rollers under sufficient pressure to bond the layers. The pressure is enough to deform the metals and reduce the combined thickness of the clad material. Heat may be applied, especially when metal are not ductile enough and this is used to make heat exchangers for refrigeration equipment. In explosive welding, the pressure to bond the two layers is provided by detonation of a sheet of chemical explosive, no heat-affected zone is produced in the bond between metals. The explosion propagates across the sheet, which tends to expel impurities and oxides from between the sheets, pieces up to 4 x 16 metres can be manufactured. The process is useful for cladding metal sheets with a corrosion-resistant layer and it is often used to improve mechanical properties or increase corrosion resistance, repair worn out parts, and fabricate metal matrix composites. The powder used in laser cladding is normally of a metallic nature, the interaction of the metallic powder stream and the laser causes melting to occur, and is known as the melt pool. This is deposited onto a substrate, moving the substrate allows the pool to solidify. This is the most common technique, however some processes involve moving the assembly over a stationary substrate to produce solidified tracks. The motion of the substrate is guided by a CAD system which interpolates solid objects into a set of tracks, a great deal of research is now being concentrated on developing automatic laser cladding machines. However, many groups are focusing their attention on developing sensors to measure the process online, such sensors monitor the clads geometry, metallurgical properties, and temperature information of both the immediate melt pool and its surrounding areas. With such sensors, control strategies are being designed such that constant observation from a technician is no longer required to produce a final product, further research has been directed to forward processing where system parameters are developed around specific metallurgical properties for user defined applications. Best technique for coating any shape => increase life-time of wearing parts, most suited technique for graded material application. Low dilution between track and substrate (unlike other welding processes and strong metallurgical bond, low deformation of the substrate and small heat affected zone. High cooling rate => fine microstructure, built part is free of crack and porosity
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Kennedy half dollar
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The Kennedy half dollar, first minted in 1964, is a fifty-cent coin currently issued by the United States Mint. Intended as a memorial to the assassinated President John F. Kennedy, use of existing works by Mint sculptors Gilroy Roberts and Frank Gasparro allowed dies to be prepared quickly, and striking of the new coins began in January 1964. The silver coins were hoarded upon their release in March 1964 by collectors, although the Mint greatly increased production, the denomination was seldom seen in circulation. Continued rises in the price of increased the hoarding—many early Kennedy half dollars have been melted for their silver. Starting with 1965-dated pieces, the percentage of silver was reduced from 90% to 40%. In 1971, when silver was eliminated entirely from the coins and production increased, the series began to see improved, a special design for the reverse of the half dollar was issued for the United States Bicentennial and was struck in 1975 and 1976. In 2014 a special edition of the Kennedy half dollar was struck in 99. 99% gold. Even though ample supplies of circulating half dollars are available from most banks. Since 2002, Kennedy half dollars have only been struck to satisfy the demand from collectors, within hours of the assassination of John F. Mrs. Kennedys reasoning was that she did not want to replace George Washington on the quarter, both Roberts and Gasparros designs had been approved by Kennedy. After the Mint produced trial strikes, Jacqueline and Robert Kennedy were invited to view them, mrs. Kennedy viewed the designs favorably, but suggested that the hair be altered slightly. Frank Gasparros reverse design of the Kennedy half dollar was also influenced by the experience he gained from designing the President John, the reverse design of the Kennedy appreciation medal depicts a larger and more detailed Presidential Seal than the one he designed on the Mints Presidential series. Gasparros placement of his initials FG is also located on both the Kennedy appreciation medal and Kennedy half dollar. Congressional approval was required for any change within 25 years of the last. In early December, Representative Henry Gonzalez introduced a bill for Kennedy to appear on the half dollar, President Johnson stated that he had been moved by letters from many members of the public to agree with the plan. The bill to authorize the Kennedy half dollar passed on December 30,1963, work was already underway on coinage dies, the use of the already-available designs allowed for the completion of the first dies on January 2,1964. Only proof coins were initially struck, the first Kennedy half dollars intended for circulation were struck at the Denver Mint on January 30,1964, followed by the Philadelphia Mint the next week. A ceremonial first strike was held at both Philadelphia and Denver on February 11,1964, the Treasury Department made the coins available to the public beginning on March 24,1964
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Quarter (United States coin)
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The quarter, short for quarter dollar, is a United States coin worth 25 cents, one-fourth of a dollar. It has a diameter of.955 inches and a thickness of.069 inches, the coin sports the profile of George Washington on its obverse and its reverse design has changed frequently. It has been produced on and off since 1796, and consistently from 1831 onward, the choice of 1⁄4 as a denomination—as opposed to the 1⁄5 more common elsewhere—originated with the practice of dividing Spanish milled dollars into eight wedge-shaped segments. At one time o bits was a nickname for a quarter. The current clad version is two layers of cupronickel, 75% copper and 25% nickel, on a core of pure copper, the total composition of the coin is 8. 33% nickel, with the remainder copper. It weighs 0.2000 avoirdupois oz, 1/80th of a pound,0.1823 troy oz, the diameter is 0.955 inches, and the width of 0.069 inches. The coin has a 0. 069-inch reeded edge, owing to the introduction of the clad quarter in 1965, it was occasionally called a Johnson Sandwich after Lyndon B. Johnson, the U. S. President at the time and it currently costs 11.14 cents to produce each coin. The U. S. Mint began producing silver quarters again in 1992 for inclusion in the annual Silver Proof set, early quarters were slightly larger in diameter and thinner than the current coin. The current regular issue coin is the George Washington quarter, showing George Washington on the front, the reverse featured an eagle prior to the 199950 State Quarters Program. The Washington quarter was designed by John Flanagan and it was initially issued as a circulating commemorative, but was made a regular issue coin in 1934. The bill passed through the Senate and was signed into legislation by President Bush on December 27,2007, the typeface used in the state quarter series varies a bit from one state to another, but is generally derived from Albertus. On June 7,2006, a bill titled Americas Beautiful National Parks Quarter Dollar Coin Act of 2008 was introduced to the House of Representatives, on December 23,2008, President George W. Bush signed the bill into law. The America the Beautiful Quarters program began in 2010 and will continue for 12 years. S. S and they were issued from 1932 through 1964. The current rarities for the Washington Quarter silver series are, Branch Mintmarks are D = Denver, coins without mintmarks are all made at the main Mint in Philadelphia. This is not due to their mintages, but rather because they are harder to find in high grades, many of these coins are worth only melt value in low grades. Other coins in the above list are expensive because of their extremely low mintages, such as the 1932 Denver and San Francisco issues. The overstruck mintmark issues are scarce and expensive, especially in the higher grades
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Dime (United States coin)
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The dime, in U. S. usage, is a ten-cent coin, one tenth of a United States dollar, labeled formally as one dime. The denomination was first authorized by the Coinage Act of 1792, the dime is the smallest in diameter and is the thinnest of all U. S. coins currently minted for circulation, being.705 inches in diameter and.053 inches in thickness. The obverse of the coin depicts the profile of President Franklin D. Roosevelt and the reverse boasts an olive branch, a torch, as of 2011, the dime coin cost 5.65 cents to produce. The word dime comes from the French word dîme, meaning tithe or tenth part, from the Latin decima. In the past prices have occasionally been quoted on signage and other materials in terms of dimes, abbreviated as d or a d with a slash through it as with the cent. The Coinage Act of 1792 established the dime, cent, and mill as subdivisions of the equal to 1⁄10. The first known proposal for a coinage system in the United States was made in 1783 by Thomas Jefferson, Benjamin Franklin, Alexander Hamilton. Hamilton, the nations first Secretary of the Treasury, recommended the issuance of six such coins in 1791, among the six was a silver coin, which shall be, in weight and value, one tenth part of a silver unit or dollar. Thus dimes are made small and thin, with the passage of the Coinage Act of 1965, the dimes silver content was removed. Dimes from 1965 to the present are composed of layers of 75 percent copper and 25 percent nickel. Starting in 1992, the U. S. Mint began issuing Silver Proof Sets annually and these sets are intended solely for collectors, and are not meant for general circulation. Since its introduction in 1796, the dime has been issued in six different major types, the name for each type indicates the design on the coins obverse. The composition of the disme was set at 89.24 percent silver and 10.76 percent copper, in 1792, a limited number of dismes were minted but never circulated. Some of these were struck in copper, indicating that the 1792 dismes were in fact pattern coins, the first dimes minted for circulation did not appear until 1796, due to a lack of demand for the coin and production problems at the United States Mint. The first dime to be circulated was the Draped Bust dime and it featured the same obverse and reverse as all other circulating coins of the time, the so-called Draped Bust/Small Eagle design. This design was the work of then-Chief Engraver Robert Scot, the portrait of Liberty on the obverse was based on a Gilbert Stuart drawing of prominent Philadelphia socialite Ann Willing Bingham, wife of noted American statesman William Bingham. The reverse design is of a bald eagle surrounded by palm and olive branches. Since the Coinage Act of 1792 required only that the cent and half cent display their denomination, all 1796 dimes have 15 stars on the obverse, representing the number of U. S. states then in the Union
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Swiss franc
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The franc is the currency and legal tender of Switzerland and Liechtenstein, it is also legal tender in the Italian exclave Campione dItalia. The Swiss National Bank issues banknotes and the federal mint Swissmint issues coins, the smaller denomination, a hundredth of a franc, is a Rappen in German, centime in French, centesimo in Italian, and rap in Romansh. The ISO code of the used by banks and financial institutions is CHF, although Fr. is used by most businesses and advertisers. Given the different languages used in Switzerland, Latin is used for inscriptions on the coins. In 1798, the Helvetic Republic introduced a currency based on the Berne thaler, the Swiss franc was equal to 6 3⁄4 grams of pure silver or 1 1⁄2 French francs. This franc was issued until the end of the Helvetic Republic in 1803, in order to solve this problem, the new Swiss Federal Constitution of 1848 specified that the federal government would be the only entity allowed to make money in Switzerland. This was followed two years later by the first Federal Coinage Act, passed by the Federal Assembly on 7 May 1850, the franc was introduced at par with the French franc. It replaced the different currencies of the Swiss cantons, some of which had been using a franc which was worth 1 1⁄2 French francs. In 1865, France, Belgium, Italy, and Switzerland formed the Latin Monetary Union, the currency was devalued by 30% following the devaluations of the British pound, U. S. dollar and French franc. In 1945, Switzerland joined the Bretton Woods system and pegged the franc to the U. S. dollar at a rate of $1 =4.30521 francs and this was changed to $1 =4.375 francs in 1949. The Swiss franc has historically considered a safe-haven currency with virtually zero inflation. However, this link to gold, which dates from the 1920s, was terminated on 1 May 2000 following a referendum. By March 2005, following a gold selling program, the Swiss National Bank held 1,290 tonnes of gold in reserves which equated to 20% of its assets. In November 2014, the referendum on the Swiss Gold Initiative which proposed a restoration of 20% gold backing for the Swiss franc was voted down, in March 2011 the franc climbed past the US$1.10 mark. In June 2011 the franc climbed past US$1.20 as investors sought safety amidst the continuation of the Greek sovereign-debt crisis, demand for francs and franc-denominated assets was so strong that nominal short-term Swiss interest rates became negative. In response to the announcement the franc fell against the euro, to 1.22 francs from 1.12 francs, the intervention stunned currency traders since the franc had long been regarded as a safe haven. The franc fell 8. 8% against the euro,9. 5% against the dollar and it was the largest plunge of the franc ever against the euro. The SNB had previously set an exchange rate target in 1978 against the Deutsche mark and maintained it, although at the cost of high inflation
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South Korea
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South Korea, officially the Republic of Korea, is a sovereign state in East Asia, constituting the southern part of the Korean Peninsula. The earliest Korean pottery dates to 8000 BC, with three kingdoms flourishing in the 1st century BC and its rich and vibrant culture left 19 UNESCO Intangible Cultural Heritages of Humanity, the third largest in the world, along with 12 World Heritage Sites. Annexed into Imperial Japan in 1910, Korea was divided after its surrender in 1945, peace has since mostly continued with the two agreeing to work peacefully for reunification and the South solidifying peace as a regional power with the worlds 10th largest defence budget. South Koreas tiger economy soared at an average of 10% for over 30 years in a period of rapid transformation called the Miracle on the Han River. A long legacy of openness and focus on innovation made it successful, today, it is the worlds fifth largest exporter with the G20s largest budget surplus and highest credit rating of any country in East Asia. It has free trade agreements with 75% of the economy and is the only G20 nation trading freely with China, the US. Since 1988, its constitution guarantees a liberal democracy with high government transparency, high personal freedoms led to the rise of a globally influential pop culture such as K-pop and K-drama, a phenomenon called the Korean Wave, known for its distinctive fashionable and trendy style. Home of the UN Green Climate Fund and GGGI, South Korea is a leader in low carbon growth, committed to helping developing countries as a major DAC. It is the third least ignorant country in the Index of Ignorance, ranking eighth highest for peaceful tolerance. It is the worlds largest spender on R&D per GDP, leading the OECD in graduates in science, the name Korea derives from the name Goryeo. The name Goryeo itself was first used by the ancient kingdom of Goguryeo in the 5th century as a form of its name. The 10th-century kingdom of Goryeo succeeded Goguryeo, and thus inherited its name, the modern spelling of Korea first appeared in the late 17th century in the travel writings of the Dutch East India Companys Hendrick Hamel. After Goryeo was replaced by Joseon in 1392, Joseon became the name for the entire territory. The new official name has its origin in the ancient country of Gojoseon, in 1897, the Joseon dynasty changed the official name of the country from Joseon to Daehan Jeguk. The name Daehan, which means great Han literally, derives from Samhan, however, the name Joseon was still widely used by Koreans to refer to their country, though it was no longer the official name. Under Japanese rule, the two names Han and Joseon coexisted, there were several groups who fought for independence, the most notable being the Provisional Government of the Republic of Korea. Following the surrender of Japan, in 1945, the Republic of Korea was adopted as the name for the new country. Since the government only controlled the part of the Korean Peninsula
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South Korean won
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The won or the Korean Republic Won is the currency of South Korea. A single won is divided into 100 jeon, the monetary subunit, the jeon is no longer used for everyday transactions, and appears only in foreign exchange rates. The won is issued by the Bank of Korea, based in the capital city, the old won was a cognate of the Chinese yuan and Japanese yen. It is derived from the hanja 圓, meaning currency or coin, the won was subdivided into 100 jeon, itself a cognate of the Chinese character 錢 which means money and also used as a unit of money in ancient times. The current won is written in hangul only. During the Colonial era, the won was replaced at par by the yen, in 1945 after World War II, Korea became divided, resulting in two separate currencies, both called won, for the South and the North. Both the Southern won and the Northern won replaced the yen at par, the first South Korean won was subdivided into 100 jeon. The South Korean won was pegged to the U. S. dollar at a rate of 15 won =1 dollar. A series of devaluations followed, the ones in part due to the Korean War. The pegs were, The first South Korean won was replaced by the hwan on February 15,1953 at a rate of 1 hwan =100 won, Republic of Korea Banknotes 5th Edition In 1946, the Bank of Joseon introduced 10- and 100-won notes. These were followed in 1949 by 5- and 1, 000-won notes, a new central bank, the Bank of Korea, was established on 12 June 1950, and assumed the duties of Bank of Joseon. Notes were introduced in denominations of 5,10 and 50 jeon, the 500-won notes were introduced in 1952. In 1953, a series of banknotes was issued which, although it gave the denominations in English in won, were, in fact, the won was reintroduced on June 10,1962, at a rate of 1 won =10 hwan. It became the legal tender on March 22,1975. Its ISO4217 code is KRW, at the reintroduction of the won in 1962, its value was pegged at 125 won = $US1. The following pegs operated between 1962 and 1980, On February 27,1980, efforts were initiated to lead to an exchange rate. The won was allowed to float on December 24,1997. Shortly after, the won was devalued to almost half of its value, until 1966, 10- and 50-hwan coins, revalued as 1 and 5 won, were the only coins in circulation
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Cryogenics
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In physics, cryogenics is the study of the production and behaviour of materials at very low temperatures. It is not well-defined at what point on the temperature scale refrigeration ends and cryogenics begins, but scientists assume a gas to be cryogenic if it can be liquefied at or below −150 °C. The U. S. National Institute of Standards and Technology has chosen to consider the field of cryogenics as that involving temperatures below −180 °C or −292.00 °F or 93.15 K. A person who studies elements that have been subjected to cold temperatures is called a cryogenicist. Cryogenicists use the Kelvin or Rankine temperature scales present in nature, Cryogenics The branches of physics and engineering that involve the study of very low temperatures, how to produce them, and how materials behave at those temperatures. Cryobiology The branch of biology involving the study of the effects of low temperatures on organisms, cryoconservation of animal genetic resources The conservation of genetic material with the intention of conserving a breed. Cryosurgery The branch of surgery applying very low temperatures to destroy malignant tissue, cryoelectronics The field of research regarding superconductivity at low temperatures. Cryotronics The practical application of cryoelectronics, Cryonics Cryopreserving humans and animals with the intention of future revival. Cryogenics is sometimes used to mean Cryonics in popular culture. The word cryogenics stems from Greek kρύο – cold + genic – having to do with production, Cryogenic fluids with their boiling point in kelvins Liquefied gases, such as liquid nitrogen and liquid helium, are used in many cryogenic applications. Liquid nitrogen is the most commonly used element in cryogenics and is legally purchasable around the world, Liquid helium is also commonly used and allows for the lowest attainable temperatures to be reached. These liquids may be stored in Dewar flasks, which are double-walled containers with a vacuum between the walls to reduce heat transfer into the liquid. Typical laboratory Dewar flasks are spherical, made of glass and protected in a metal outer container, Dewar flasks for extremely cold liquids such as liquid helium have another double-walled container filled with liquid nitrogen. Dewar flasks are named after their inventor, James Dewar, the man who first liquefied hydrogen, thermos bottles are smaller vacuum flasks fitted in a protective casing. Cryogenic barcode labels are used to mark dewar flasks containing these liquids, Cryogenic transfer pumps are the pumps used on LNG piers to transfer liquefied natural gas from LNG carriers to LNG storage tanks, as are cryogenic valves. The field of cryogenics advanced during World War II when scientists found that metals frozen to low temperatures showed more resistance to wear, based on this theory of cryogenic hardening, the commercial cryogenic processing industry was founded in 1966 by Ed Busch. This evolved in the late 1990s into the treatment of other parts, cryogens, such as liquid nitrogen, are further used for specialty chilling and freezing applications. Some chemical reactions, like those used to produce the active ingredients for the popular statin drugs, special cryogenic chemical reactors are used to remove reaction heat and provide a low temperature environment
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Bullet
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The word bullet is a firearm term. A bullet is a projectile expelled from the barrel of a firearm, the term is from Middle French and originated as the diminutive of the word boulle which means small ball. Bullets are made of a variety of materials and they are available singly as they would be used in muzzle loading and cap and ball firearms, as part of a paper cartridge, and much more commonly as a component of metallic cartridges. Bullets are made in a numbers of styles and constructions depending on how they will be used. Many bullets have specialized functions, such as hunting, target shooting, training, defense, a bullet is not a cartridge. In paper and metallic cartridges a bullet is one component of the cartridge, bullet sizes are expressed by their weight and diameter in both English and Metric measurement systems. For example.22 caliber 55 grain bullets or 5. 56mm 55 grain bullets are the same caliber, the word bullet is often used colloquially to refer to a cartridge, which is a combination of the bullet, paper or metallic case/shell, powder, and primer. This use of bullet, when cartridge is intended, leads to confusion when the components of a cartridge are discussed or intended, the bullets used in many cartridges are fired at a muzzle velocity faster than the speed of sound. Meaning they are supersonic and thus can travel a substantial distance, bullet speed through air depends on a number of factors such as barometric pressure, humidity, air temperature, and wind speed. Subsonic cartridges fire bullets slower than the speed of sound and so there is no sonic crack and this means that a subsonic cartridge such as.45 ACP can be effectively suppressed to be substantially quieter than a supersonic cartridge such as the.223 Remington. Bullets do not normally contain explosives, but damage the target by impact. The first use of gunpowder in Europe was recorded in 1247 and it had been used in China for hundreds of years. Later in 1364 hand cannon appeared, early projectiles were made of stone. Stone was used in cannon and hand cannon, in cannon it was eventually found that stone would not penetrate stone fortifications which gave rise to the use of heavier metals for the round projectiles. Hand cannon projectiles developed in a similar following the failure of stone from siege cannon. The first recorded instance of a ball from a hand cannon penetrating armor occurred in 1425. In this photograph of shot retrieved from the wreck of the Mary Rose which was sunk in 1545, the round shot are clearly of different sizes and some are stone while others are cast iron. The development of the hand culverin and matchlock arquebus brought about the use of cast lead balls as projectiles, bullet is derived from the French word boulette, which roughly means little ball
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Gauge (bore diameter)
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The gauge of a firearm is a unit of measurement used to express the inner diameter of the barrel. Thus there are twelve 12-gauge balls per pound, etc, the term is related to the measurement of cannon, which were also measured by the weight of their iron round shot, an 8 pounder would fire an 8 lb ball. These very large rifles, sometimes called elephant guns, were intended for use in India, gauge is abbreviated ga. ga, or G. The space between the number and the abbreviation is often left out, as in 12ga. Therefore, a shotgun or n-bore rifle has a bore diameter of approximately d n =11.33 Explanation. Divide it by 11.3 to find the volume of the ball, multiply it by 0.75 and divide it by pi, then find its cube root, to find its radius in cm. Multiply it by 2 to find the diameter in cm, Divide it by 2.54 to find the diameter in inches. This simplifies to d n =1.67 / n 3 to find the diameter in inches of the barrel of an n-gauge shotgun. Therefore, if the diameter is in inches, n =4.66 / d n 3 Another source for a gauge size formula can be found in page Shotgun shell#Shotgun gauge diameter formula. Since shotguns were not originally intended to fire projectiles, but rather a compressible mass of shot. The fact that most shotgun bores are not cylindrical also causes deviations from the bore diameter. The chamber of the gun is larger, to accommodate the thickness of the walls. The forcing cone can be as short as a fraction of an inch, or as long as a few inches on some guns. At the muzzle end of the barrel, the choke can constrict the bore even further, so measuring the diameter of a shotgun is not a simple process. Shotgun bores are commonly overbored or backbored, meaning that most of the bore is larger than the value given by the formula. This is claimed to reduce recoil and improve patterning. A 12-gauge shotgun, nominally 18.5 mm, can range from a tight 18.3 mm to an extreme overbore of 20.3 mm. Some also claim an increased velocity with the barrels, up to 15 m/s
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Nickel silver
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Nickel silver, Mailechort, German silver, Argentan, new silver, nickel brass, albata, alpacca, or electrum is a copper alloy with nickel and often zinc. The usual formulation is 60% copper, 20% nickel and 20% zinc, Nickel silver is named for its silvery appearance, but it contains no elemental silver unless plated. The name German silver refers to its development by 19th-century German metalworkers in imitation of the Chinese alloy known as paktong, all modern, commercially important nickel silvers contain significant amounts of zinc, and are sometimes considered a subset of brass. Nickel silver was first known and used in China, during the Qing dynasty, it was smuggled into various parts of the East Indies, despite a government ban on the export of nickel silver. It became known in the west from imported wares called bai-tong or paktong, according to Berthold Laufer, it was identical with khar sini, one of the seven metals recognized by Jābir ibn Hayyān. In Europe, consequently, it was at first called paktong, the earliest European mention of paktong occurs in the year 1597. From then until the end of the century there are references to it as having been exported from Canton to Europe. German imitations of paktong, however, began to appear from about 1750 onward, in 1770 the Suhl metalworks were able to produce a similar alloy. In 1823 a German competition was held to perfect the production process, the brothers Henniger in Berlin and Ernst August Geitner in Schneeberg independently achieved this goal. The manufacturer Berndorf named the trademark brand Alpacca, which became known in northern Europe for nickel silver. In 1830 the German process of manufacture was introduced into England and that is why today the alloy has lost its original name and is generally known as German silver. In 1832, a form of German silver was also developed in Birmingham, after 1840, the development of electroplating caused nickel silver to become widely used. It formed an ideal, strong and bright substrate for the plating process and it was also used unplated in applications such as cheaper grades of cutlery. Nickel silver first became popular as a metal for silver-plated cutlery and other silverware. It is widely used in the production of coins and its industrial and technical uses include marine fittings and plumbing fixtures for its corrosion resistance, and heating coils for its high electrical resistance. In the 19th century, particularly after 1868, Plains Indian jewelers were able to easily acquire sheets of German silver and they used them to cut, stamp, and cold hammer a wide range of accessories and also horse gear. Nickel silver is the metal of choice among contemporary Kiowa and Pawnee metalsmiths in Oklahoma, many of the metal fittings on modern higher-end equine harness and tack are of nickel silver. Early in the century, German silver was used by automobile manufacturers before the advent of steel sheet metal, for example
43.
Fender Musical Instruments Corporation
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Fender Musical Instruments Corporation, commonly referred to simply as Fender, is an American manufacturer of stringed instruments and amplifiers. It is known for its electric guitars and bass guitars, such as the Stratocaster, Telecaster, Precision Bass. Its headquarters are in Scottsdale, Arizona, the company, previously named the Fender Electric Instrument Manufacturing Company, was founded in Fullerton, California, by Clarence Leonidas Leo Fender in 1946. The company is a privately held corporation with Andy Mooney serving as the Chief Executive Officer, the company filed for an initial public offering in March 2012, but this was withdrawn five months later. In addition to its Scottsdale headquarters, Fender has manufacturing facilities in Corona, California and Ensenada, Baja California. The company also makes and / or distributes acoustic guitars, electric basses, mandolins, banjos, and electric violins, as well as amplifiers, bass amplifiers. Other Fender brands include Squier, Jackson, Charvel, EVH guitars and amplifiers in collaboration with Eddie Van Halen, in 1950, Fender introduced the first mass-produced solid-body Spanish-style electric guitar, the Telecaster. Following its success, Fender created the first mass-produced electric bass, in 1954, Fender unveiled the Stratocaster guitar. With the Telecaster and Precision Bass on the market for some time, the Strats comfortable contoured edges and in-built vibrato system led to its soaring popularity. The solid wood bodies of Fenders instruments allowed for minimal feedback with high-gain amplification, the Fender guitars were popular with musicians in a variety of genres and are now revered for their build quality and tonal excellence. The company began as Fenders Radio Service in late 1938 in Fullerton and it got its name from the surname of its founder Leo Fender. All designs were based on research developed and released to the domain by Western Electric in the 1930s. The business also sidelined in carrying records for sale and the in rental of company-designed PA systems, Leo became intrigued by design flaws in contemporary musical instrument amplifiers and began building amplifiers based on his own designs or modifications to designs. Production began in 1945 with Hawaiian lap steel guitars and amplifiers sold as sets, by the end of the year Fender became convinced that manufacturing was more profitable than repair and he decided to concentrate on that business instead. Kauffman remained, however, unconvinced and he and Fender amicably parted ways by early 1946, at that point Leo renamed the company the Fender Electric Instrument Company. The service shop remained open until 1951, although Leo Fender did not personally supervise it after 1947, a custom lap steel guitar made in 1946 for his friend Noel Boggs was probably the very first product of the new company, already sporting the familiar Big F logo. In the late 1940s, Leo Fender began to experiment with more conventional guitar designs, as early as 1949, the familiar shape of the Telecaster can be made out in some of Fenders prototypes. Early Telecasters were plagued with issues, Leo Fender boasted the strength of the Telecasters one-piece pine neck while early adopters lamented its tendency to bow in humid weather
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Humbucker
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A humbucking pickup, humbucker, or double coil, is a type of electric guitar pickup that uses two coils to buck the hum picked up by coil pickups. Most pickups use magnets to produce a field around the strings. Humbuckers work by pairing a coil with the poles of its magnets oriented up. By connecting the coils together out of phase, the interference is reduced via phase cancellation. The string signals from both coils add up instead of canceling, because the magnets are placed in opposite polarity. The coils can be connected in series or in parallel in order to achieve this hum-cancellation effect, in addition to electric guitar pickups, humbucking coils are sometimes used to cancel hum in dynamic microphones. Hum is caused by the magnetic fields created by transformers. While playing a guitar without humbuckers, a musician would hear a hum through the pickups during quiet sections of music, sources of studio and stage hum include high-power amps, processors, mixers, motors, power lines, and other equipment. Compared to unshielded single coil pickups, humbuckers dramatically reduce hum, the twin coiled guitar pickup invented by Arnold Lesti in 1935 is arranged as a humbucker, and the patent USRE20070 describes the noise cancelation and current summation principles of such a design. This Electric Translating Device employed the solenoid windings of the pickup to magnetize the steel strings by means of switching on a short D. C. charge before switching over to amplification, in 1938 A. F. Knoblaugh invented a pickup for stringed instruments involving 2 stacked coils. This pickup was to be used in pianos, since he was working for Baldwin Piano at the time, the iron cores of these pickups were magnetized to have their north-south poles at the opposite ends of the core, rather than the now more common top-bottom orientation. To overcome the hum problem for guitars, a humbucking pickup was invented by Seth Lover of Gibson under instruction of then president Ted McCarty, about the same time Ray Butts developed a similar pickup that was taken up by Gretsch guitars. Although Gibsons patent was filed almost 2 years before Gretschs, Gibsons patent was issued 4 weeks after Gretschs, both patents describe a reverse wound and reverse polarity pair of coils. A successful early humbucking pickup was the so-called PAF invented by Seth Lover in 1955, humbuckers are also known as dual-coil, double-coil, or hum-canceling pickups. In any magnetic pickup, a guitar string, magnetized by a fixed magnet within the pickup induces an alternating voltage across its coil. Guitar pickups reproduce this noise, which can be quite audible, the direction of voltage induced across a coil by the moving string depends on both the coil winding direction and the polarity of the fixed magnet. On the other hand, the direction of current induced by external fields is only dependent on the direction of winding, therefore a humbucker has two coils wound in such a way to cancel hum and maximize signal when they are connected. By convention humbucker coils are both wound counterclockwise, however typically the outside ends of the coils are connected together so that the starts are out of phase
