Costa Rica

. IUPAC officially prefers the use of aluminium in its internal publications, although several IUPAC publications use the spelling aluminum.[8]. During the 19th century Chinese and Italian inmigrants came to the country to work on the construction of the railroad system as well. Hence their periodic table includes both, but places aluminium first [7]. The Atlantic coast, meanwhile, was populated with African slaves in the 17th and 18th centuries, altough most Caribbean Costa Ricans of African ascent descend from Jamaican workers brought in during the 19th century to work in the construction of railways connecting the urban populations of the Central Plateau to the port of Limon on the Caribbean coast. The International Union of Pure and Applied Chemistry (IUPAC) adopted aluminium as the standard international name for the element in 1990, but three years later recognised aluminum as an acceptable variant. However, the indigenous people have influenced modern Costa Rican culture to a relatively small degree, as most of the Indians died from disease and mistreatment by the Spaniards. Consequently it is the more common of the two spellings in global terms, even though there may be more users of aluminum in the English-speaking world.

The center and southern portions of the country had Chibcha influences. Outside English, the "ium" spelling is widespread: the word is aluminium in French and German, and identical or similar forms are used in many other languages. The northwest of the country, Nicoya, was the southernmost point of Nahuatl cultural influence when the Spanish conquerors (conquistadores) came in the 16th century. However, in Canada both spellings are common, due to the multiple influences on the language of its proximity to the United States, its British colonial past and the large number of native French speakers. Costa Rica was the point where the Mesoamerican and South American native cultures met. Elsewhere in the English-speaking world the spelling aluminium predominates, and the spelling aluminum is largely unknown. Costa Rica boasts a varied history. In the United States, the spelling aluminium is largely unknown, and the spelling aluminum predominates.

Their spoken accent is rather closer to certain areas of Colombia than its Central American counterparts. In the English-speaking world, the spellings (and associated pronunciations) aluminium and aluminum are both in common use in scientific and nonscientific contexts. Costa Rican traditions and culture tend to retain a strong degree of Spanish influence. In 1926, the American Chemical Society officially decided to use aluminum in its publications, and American dictionaries typically label the spelling aluminium as a British variant. It encapsulates the pervading ideology of living in peace in a calm, unflustered manner, appreciating a life surrounded by nature and family and friends. Hall's domination of production of the metal ensured that the spelling aluminum became the standard in North America, even though the Webster Unabridged Dictionary of 1913 continued to use the -ium version. The phrase "Pura Vida" (literally pure life) is a motto ubiquitous in Costa Rica. It has consequently been suggested that the spelling on the flyer was a simple spelling mistake rather than a deliberate choice to use the -um spelling.

Visitors from the United States are often referred to as gringos, which is virtually always congenial in nature. However in 1892 Charles Martin Hall used the -um spelling in an advertising handbill for his new efficient electrolytic method for the production of aluminium, despite using the -ium spelling in all of his patents filed between 1886 and 1903. The tico ideal is that of a very friendly, helpful, laid back, unhurried, educated and environmentally aware people, with little worry for deadlines or the "normal" stresses of United States life. Curiously, the United States adopted the -ium for most of the 19th century with aluminium appearing in Webster's Dictionary of 1828. 'momentico' instead of 'momentito'). Nevertheless, -um spellings for elements were not unknown at the time: platinum, which had been known to Europeans since the 16th century, molybdenum, which was discovered in 1778, and tantalum, which was discovered in 1802, all have spellings ending in -um. "Tico" comes from the locally popular usage of "tico" diminutive suffixes (eg. This had the advantage of conforming to the -ium suffix precedent set by other newly discovered elements of the period: potassium, sodium, magnesium, calcium, and strontium (all of which Davy had isolated himself).

The locals refer to themselves as tico, maje or mae (sort of "man", actually maje means "dumb") idiom in a very popular and "only with close friends" way, or tica (female). 72, 1812).
. Review VIII. [4] In addition there are many Americans who either come to retire or move to the country to live. (Q. Another one percent is ethnically Chinese. Aluminium, for so we shall take the liberty of writing the word, in preference to aluminum, which has a less classical sound.

Altogether, Costa Ricans of mestizo and European descent account for a combined 94 percent (the vast majority being of Spanish decent). The same year, an anonymous contributor to the Quarterly Review objected to aluminum, and proposed the name aluminium. Descendants of black 19th-century Jamaican immigrant workers constitute an English-speaking minority and at three percent of the population number about 96,000. In 1812 he changed the name to aluminum to match its Latin root. In Guanacaste Province, most of the population descends from a mix of the Chorotega Indians, Bantu Africans and Spaniards. In 1808, Humphry Davy originally proposed the name alumium while trying to isolate the new metal electrolytically from the mineral alumina. The pure indigenous population today numbers about 29,000, less than one percent of the population. For this reason, mercury thermometers are not allowed on many airliners, as aluminium is a common structural component in aircraft.

Costa Rica has a population of 4,016,173 persons (July 2005 est.) In the central part of the country, most people are of European descent but some are also mestizos (to varying degrees).[3] Because of little intermarriage, most of the population today retain European complexions. Within a few hours, even a heavy structural beam can be significantly weakened.
. For example, just a small amount of mercury applied to the surface of a piece of aluminium can break up the aluminium oxide barrier usually present.
. Care must be taken to prevent aluminium from coming into contact with certain chemicals that can cause it to corrode quickly. Also see:. In any event, if there is any toxicity of aluminium it must be via a very specific mechanism, since total human exposure to the element in the form of naturally occurring clay in soil and dust is enormously large over a lifetime.

The entity entrusted to do genetic and biochemical prospection on Costa Rica's biological wealth is the INBIO (Instituto Nacional de Biodiversidad), and it is allowed to collect royalties on any biological discoveries of medical importance. It has been suggested that aluminium may be linked to Alzheimer's disease, although that research has recently been refuted; aluminium accumulation may be a consequence of the Alzheimer's damage, not the cause. Costa Rica as a whole has about 850 species of birds. Excessive consumption of antacids containing aluminium compounds and excessive use of aluminium-containing antiperspirants are more likely causes of toxicity. Over 400 types of bird can be found here, as well as over 100 species of mammal. In other people, aluminium is not considered as toxic as heavy metals, but there is evidence of some toxicity if it is consumed in excessive amounts, although the use of aluminium cookware, popular because of its corrosion resistance and good heat conduction, has not been shown to lead to aluminium toxicity in general. The Monteverde Cloud Forest Reserve hosts 2,000 plant species including numerous orchids. Aluminium is one of the few abundant elements that appears to have no beneficial function in living cells, but a few percent of people are allergic to it — they experience contact dermatitis from any form of it: an itchy rash from using styptic or antiperspirant products, digestive disorders and inability to absorb nutrients from eating food cooked in aluminium pans, and vomiting and other symptoms of poisoning from ingesting such products as Rolaids , Amphojel, and Maalox (antacids).

Giant leatherback, hawksbill, and loggerhead turtles also nest here. [6]. is considered the most important nesting site for this specie. Welford Castleman Jr (Penn State University). Tortuguero National Park (the name Tortuguero can be translated as turtle catcher or turtle hunter) is home to spider, howler and White-throated Capuchin monkeys, the Three-toed sloth, 320 species of birds (including eight species of parrots), a variety of reptiles, but is mostly recognized for the annual nesting of the endangered green turtle. Khanna (Virginia Commonwealth University) and A. One national park that is internationally renowned among ecologists for its biodiversity (including big cats and tapirs) and where visitors can expect to see an abundance of wildlife is the Corcovado National Park. The research teams were led by Shiv N.

Over 25% of Costa Rica is composed of protected forests and reserves. This discovery is reported to give rise to the possibility of a new characterisation of the periodic table: superatoms. Costa Rica has no military or navy, but an abundance of wildlife; it has been said that the soldiers are the leaf cutter ants, the pilots are the macaws and the navy ships are the whales. The researchers also bound 12 iodine atoms to an Al₁₃ cluster to form a new class of polyiodide. While the country has only about 0.1% of the world's land mass, it contains 5% of the world's biodiversity. In the journal Science of 14 January 2005 it was reported that clusters of 13 aluminium atoms (Al₁₃) had been made to behave like an iodine atom; and, 14 aluminium atoms (Al₁₄) behaved like an alkaline earth atom. Costa Rica is home to a rich variety of plants and animals. Possibly, the energy released by the decay of ²⁶Al was responsible for the remelting and differentiation of some asteroids after their formation 4.6 billion years ago.

For instance, during the Cold War Costa Rica was the first Central American country to have diplomatic ties with the Soviet Union as a way to boost its coffee exports, to the dismay of the Nixon administration. Meteorite research has also shown that ²⁶Al was relatively abundant at the time of formation of our planetary system. Nevertheless, economic pragmatism may prevail over ideology. After falling to Earth, atmospheric shielding protects the meteorite fragments from further ²⁶Al production, and its decay can then be used to determine the meteorite's terrestrial age. Costa Rica's main foreign policy objective is to foster human rights and sustainable development as a way to secure stability and growth. Meteorite fragments, after departure from their parent bodies, are exposed to intense cosmic-ray bombardment during their travel through space, causing substantial ²⁶Al production. Costa Rica is currently a member of the Cairns Group, an alliance of countries opposed to agricultural subsidies in the first world. Cosmogenic ²⁶Al was first applied in studies of the Moon and meteorites.

Costa Rica has no embassy in Cuba, but does have an embassy in Israel, and has diplomatic relations with the Republic of China in Taiwan, not the People's Republic of China. The ratio of ²⁶Al to ¹⁰Be has been used to study the role of transport, deposition, sediment storage, burial times, and erosion on 10⁵ to 10⁶ year time scales. instead set up such a center in El Salvador, a country alleged to have a tradition of human rights equivocacy. Aluminium isotopes have found practical application in dating marine sediments, manganese nodules, glacial ice, quartz in rock exposures, and meteorites. The U.S. ²⁶Al is produced from argon in the atmosphere by spallation caused by cosmic-ray protons. offers to set up a security training center in the country on the grounds that a country with no army could not harbor a center with possible military purposes. Only ²⁷Al (stable isotope) and ²⁶Al (radioactive isotope, t_1/2 = 7.2 × 10⁵ y) occur naturally, however ²⁷Al has a natural abundance of 100%.

Costa Rica is a member of the International Criminal Court and rejected U.S. Aluminium has nine isotopes, whose mass numbers range from 23 to 30. While Costa Rica is not expected to join the tide of new left-leaning governments in Latin America its foreign policy does not always line up with the interests of the USA. Suriname depends on aluminium exports for 70% of its export earnings.[5]. dollar; currently about 600 to the euro. In 2004, China was the top world producer of aluminium. The unit of currency is the colón (CRC), which trades around 500 to the U.S. Smelters tend to be located where electric power is plentiful and inexpensive, such as South Africa, the South Island of New Zealand, Australia, China, Middle-East, Russia, Iceland and Quebec in Canada.

Economic growth stood at 4.2%, nevertheless the country faced high inflation (14%) and a trade deficit of 5.2%. Electric power represents about 20 to 40% of the cost of producing aluminium, depending on the location of the aluminium smelter. For the fiscal year 2005 the country showed a government deficit of 2.1%, internal revenue increased an 18%, exports increased a 12.8% and the number of visiting tourists increased a 19%, reaching 1.5 million people. Trials have been reported with 500 kA cells. Trade with South East Asia and Russia has boomed during 2004 and 2005, and the country is expected to obtain full Asia-Pacific Economic Cooperation Forum (APEC) membership by 2007 (the country became an observer in 2004). State-of-the-art smelters operate with about 350 kA. Several global high tech corporations have already started developing in the area exporting goods including chip manufacturer Intel and pharmaceutical companies such as Procter & Gamble and Glaxo Smith Kline. Reduction line current for older technologies are typically 100 to 200 kA.

Relatively high levels of education among its residents make the country an attractive investing location. The most modern smelters reach approximately 12.8 kW·h/kg (46.1 MJ/kg). The central government offers tax exemptions for those who are willing to invest in the country. The world-wide average specific energy consumption is approximately 15±0.5 kilowatt-hours per kilogram of aluminium produced (52 to 56 MJ/kg). The economy has been expanding for Costa Rica in part because the Government had implemented a seven year plan of expansion in the high tech industry. Aluminium electrolysis with the Hall-Héroult process consumes a lot of energy, but alternative processes were always found to be less viable economically and/or ecologically. Costa Rica's location in the Central American isthmus provides easy access to American markets as it has the same time zone as the central part of the United States and direct ocean access to Europe and Asia. After 5 to 10 years, depending on the current used in the electrolysis, a cell has to be reconstructed completely, because the cathodes are completely worn.

Costa Rica's economy is mostly based on agriculture (coffee, bananas, pineapples, ornamentals), but in recent times ecotourism, electronics, financial outsourcing and software develoment are rapidly expanding sources of business. Cathodes do erode, mainly due to electrochemical processes. Costa Rica consists of seven provinces:. The carbon cathode is protected by the liquid aluminium inside the cells. See also: Military of Costa Rica. Contrary to the anodes, the cathodes are not consumed during the operation, since there is no oxygen present at the cathode. Costa Rica has no military by constitution but maintains domestic Police and armed National Guard forces for internal security. The anodes in a reduction must therefore be replaced regularly, since they are consumed in the process:.

Autonomous state agencies enjoy considerable operational independence; they include the telecommunications and electrical power monopoly, the nationalized commercial banks, the state insurance monopoly, and the social security agency. This carbon anode is then oxidised by the oxygen. There are no provincial legislatures. At the positive electrode (anode) oxygen gas is formed:. Governors appointed by the president head the country's seven provinces, but they exercise little power. The aluminium metal then sinks to the bottom and is tapped off. Costa Rica uses a form of proportional representation to elect its national legislative body. Here the aluminium ion is being reduced (electrons are added).

Arias is promoter of free trade and supports the free trade agreement with the United States which is the source of a great controversy that might develop in protests around the country in the upcoming months. The reaction at the negative cathode is. In April 2003 the prohibition was officially recognized, in a highly polemic resolution, as anti-constitutional allowing Óscar Arias (Nobel Peace Prize, 1987) to run for President a second time in the upcoming 2006 elections. Once the ore is in the molten state, its ions are free to move around. An amendment to the constitution to allow second presidential terms was proposed and also the constitutionality of the prohibition against a second presidential term has been challenged in the courts. Both of the electrodes used in the electrolysis of aluminium oxide are carbon. A constitutional amendment approved in 1969 limited presidents and deputies to one term, although a deputy may run again for an Assembly seat after sitting out a term. The electolytic process replaced the Wöhler process, which involved the reduction of anhydrous aluminium chloride with potassium.

The president and 57 Legislative Assembly deputies are elected for 4-year terms. Previously, the Deville process was the predominant refining technology. There also are two vice presidents and a 15-member cabinet that includes one of the vice presidents. This is done using the so-called Bayer process. Executive responsibilities are vested in a president, who is the country's center of power. The aluminium oxide (a white powder) is obtained by refining bauxite, which is red since it contains 30 to 40% iron oxide. It is seen as one of the most stable countries in Latin America. Cryolite is a mixture of aluminium, sodium, and calcium fluorides: (Na₃AlF₆).

Costa Rica is a democratic republic with a strong constitution. Cryolite was originally found as a mineral on Greenland, but has been replaced by a synthetic cryolite. Costa Rica protects over 25% of its national territory within national parks. By this process, the actual operational temperature of the reduction cells is around 950 to 980 °C. The country is highly recognized and praised for its national park system: a developed and progressive system which stresses ecotourism. Therefore, it is extracted by electrolysis — the aluminium oxide is dissolved in molten cryolite and then reduced to the pure metal. The largest lake in Costa Rica is Lake Arenal. Direct reduction, with carbon for example, is not economically viable since aluminium oxide has a melting point of about 2000 °C.

Cocos Island stands out because of its distance from continental landmass (24 km² [9.25 mi²], 500 km [310 mi] from Puntarenas coast), but Calero Island is the biggest island of the country (151.6 km² [58.5 mi²]). Aluminium is a reactive metal and it is hard to extract it from its ore, aluminium oxide (Al₂O₃). Costa Rica also comprises several islands. Other sources for recycled aluminium include automobile parts, windows and doors, appliances, containers and other products. The highest volcano in the country is the Irazú Volcano (3,431 m or 11,257 feet). It was, however, a low-profile activity until the late 1960s when the exploding popularity of aluminium beverage cans finally placed recycling into the public consciousness. The highest point in the country is Cerro Chirripo, with 3,810 metres (12,500 ft), the second highest peak in Central America, after Volcan Tajumulco in Guatemala. A common practice since the early 1900s, aluminium recycling is not new.

state of West Virginia and about half the size of Ireland. Refining aluminium requires enormous amounts of electricity; recycling it requires only 5% of the energy to produce it. In total, Costa Rica comprises 51,100 km² (19,730 mi²), of which 50,610 km² (19,540 mi²) is land and 440 km² (170 mi²) is water, making it slightly smaller than the U.S. Recycling involves simply melting the metal, which is far less expensive than creating it from ore. Costa Rica also borders Nicaragua to the north (309 km [192 mi] of border) and Panama to the south-southeast (639 km [397 mi] of border). Recovery of this metal from scrap (via recycling) has become an important component of the aluminium industry. It borders both the Caribbean Sea (to the east) and the North Pacific Ocean (to the west), with a total of 1,290 km (802 mi) of coastline (212km [132 mi] on the Caribbean coast and 1,016 km [631 mi] on the Pacific). The very reason for which aluminium is used in many applications is why it is so hard to produce.

Costa Rica is located on the Central American isthmus, 10° North of the equator and 84° West of the Prime Meridian. The reason is that aluminium is oxidised very rapidly and that its oxide is an extremely stable compound that, unlike rust on iron, does not flake off. Land ownership is widespread and Electronics is a rapidly expanding industry. Aluminium is among the most difficult metals on Earth to refine, despite the fact that it is one of the planet's most common. Costa Rica (Spanish for "Rich Coast"), although still a largely agricultural country, has achieved a relatively high standard of living. Aluminium was, when it was first discovered, extremely difficult to separate from its ore. In 1949, José Figueres Ferrer abolished the army; and since then Costa Rica has been one of the few countries to operate within the democratic system without the assistance of a military. Aluminium has been produced in commercial quantities for just over 100 years.

Since the late 19th century only two brief periods of violence have marred its democratic development. Others had to make do with gold ones. Costa Rica has avoided the violence that has plagued Central America; it is seen as an example of political stability in the region, and is referred to as the "Switzerland of the Americas". Napoleon III of France had a set of aluminium plates reserved for his finest guests. From the 1840s on, Costa Rica was an independent nation. Although aluminium is the most abundant metallic element in Earth's crust (believed to be 7.5% to 8.1%), it is very rare in its free form and was once considered a precious metal more valuable than gold. In 1824, the capital moved to San José. [4].

After briefly joining the Mexican Empire of Agustín de Iturbide (see: History of Mexico and Mexican Empire), Costa Rica became a state in the United Provinces of Central America (see: History of Central America) from 1823 to 1839. By 1942, however, new hydroelectric power projects such as the Grand Coulee Dam gave the United States something Nazi Germany could not hope to compete with, namely the capability of producing enough aluminium to manufacture sixty thousand warplanes in four years. The provincial capital was in Cartago. Germany became the world leader in aluminium production soon after Adolf Hitler seized power. Costa Rica was then the southernmost province in the Spanish territory of New Spain. [3]. The native people of the Mayans and Aztecs were conquered by Spain in the 16th century. Aluminium was selected as the material to be used for the apex of the Washington Monument, at a time when one ounce cost twice the daily wages of a common worker in the project.

These groups are also believed to have created the Stone spheres of Costa Rica, between 200 BC and AD 1600. Hunt of Pittsburgh, PA, started the Pittsburgh Reduction Company, renamed to Aluminum Company of America in 1907, later shortened to Alcoa. This has recently been redefined to include the Isthmo-Colombian area, defined by the presence of groups that spoke Chibchan languages. Upon approval of his patent in 1889, Hall, with the financial backing of Alfred E. In Pre-Columbian times the Native Americans in what is now Costa Rica were part of the Intermediate Area located between the Mesoamerican and Andean cultural regions. The invention of the Hall-Héroult process in 1886 made extracting aluminium from minerals cheaper, and is now the principal method in common use throughout the world. . The American Charles Martin Hall of Oberlin, OH applied for a patent (400655) in 1886 for an electrolytic process to extract aluminium using the same technique that was independently being developed by the Frenchman Paul Héroult in Europe.

Costa Rica was the first country in the world to constitutionally abolish its army. The Frenchman Henri Saint-Claire Deville improved Wöhler's method in 1846 and described his improvements in a book in 1859, chief among these being the substitution of sodium for the considerably more expensive potassium. The Republic of Costa Rica is a country in Central America, bordered by Nicaragua to the north, Panama to the south-southeast, the Pacific Ocean to the west and south, and the Caribbean Sea to the east. Berthier who discovered aluminium in bauxite ore and successfully extracted it.
September 15, 1821. Therefore almanacs and chemistry sites often list Øersted as the discoverer of aluminium.[2] Still it would further be P.
 - Date. However, the metal had been produced for the first time two years earlier in an impure form by the Danish physicist and chemist Hans Christian Ørsted.

Debi Nova, singer. Friedrich Wöhler is generally credited with isolating aluminium (Latin alumen, alum) in 1827 by mixing anhydrous aluminium chloride with potassium. Maribel Guardia, singer, actress, model. In 1808, Humphry Davy identified the existence of a metal base of alum, which he named (see Spelling section). Chavela Vargas, singer. In 1761 Guyton de Morveau suggested calling the base alum 'alumine'. National hero. Further Joseph Needham suggested finds in 1974 showed the ancient Chinese used aluminium (see "notes" linked above).

Juan Santamaría. The ancient Greeks and Romans used salts of this metal as dyeing mordants and as astringents for dressing wounds, and alum is still used as a styptic. Olympic gold medallist. Connections made with these standard industry products are as safe and reliable as copper connections. Claudia Poll. New alloys are used for aluminium building wire today in combination with aluminium terminations. Clodomiro Picado Twight, Toxicologist. A properly done crimp, requiring high pressure produced by the proper tool, is tight enough not only to eliminate any thermal expansion of the aluminium, but also to exclude any atmospheric oxygen and thus prevent corrosion between dissimilar metals.

Franklin Chang Díaz, Astronaut. Otherwise, aluminium wiring can be terminated by crimping it to a short "pigtail" of copper wire, which can be treated as any other copper wire. José Figueres Ferrer, National caudillo and President of the Republic (1948–1949, 1953–1958, and 1970–1974. Older fixtures of this type are marked "Al/Cu", and newer ones are marked "CO/ALR". Óscar Arias Sánchez, Nobel Peace Prize winner (1987) and President of the Republic (1986–1990). However, aluminium wiring can be safely used with fixtures whose connections are designed to avoid loosening and overheating. Instituto Nacional de Biodiversidad [2]. As a result, aluminium household wiring has become unpopular, and in many jurisdictions it is not permitted in very small sizes in new construction.

List of birds of Costa Rica. In combination, these properties caused connections between electrical fixtures and aluminium wiring to overheat which resulted in several fires. Wildlife of Costa Rica. More specifically:. San José (Capital)(political and economical center of Costa Rica, see image below). Unfortunately, many of the wiring fixtures at the time were not designed to accept aluminium wire. Puntarenas (along most of the Pacific coast, with a large bulge in the south-west and a smaller one at the northern end at both sides of the Golfo de Nicoya, where the homonymous capital is located). Because of its high conductivity and relatively low price compared to copper at the time, aluminium was introduced for household electrical wiring to a large degree in the United States in the 1960s.

Limón (caribbean coast, agricultural and eco-tourism area). If the misalignment is not too severe, once cooled they can be bent back into alignment with no negative consequences; of course, if the frame is properly designed for rigidity (see above), this will require enormous force. Heredia (central; north of capital, manufacturing and core of Costa Rica's IT industry). Stresses from overheating aluminium can be relieved by heat-treating the parts in an oven and gradually cooling, in effect annealing the stresses; this can also result, however, in the part becoming distorted as a result of these stresses, so that such heat-treating of welded bicycle frames, for instance, results in a significant fraction becoming misaligned. Guanacaste (north-west, important touristic and agricultural area). For this reason, many uses of aluminium in the aerospace industry avoid heat altogether by joining parts using adhesives; this was also used for some of the early aluminium bicycle frames in the 1970s, with unfortunate results when the aluminium tubing corroded slightly, loosening the bond of the adhesive and leading to failure of the frame. Cartago (former Costa Rican Provicial capital during colonial times). Aluminium also will accumulate internal stresses and strains under conditions of overheating; while not immediately obvious, the tendency of the metal to "creep" under sustained stresses results in delayed distortions, for instance the commonly observed warping or cracking of aluminium automobile cylinder heads after an engine is overheated, sometimes as long as years later, or the tendency of welded aluminium bicycle frames to gradually twist out of alignment from the stresses accumulated during the welding process.

Alajuela (central; north of capital San José, agriculture and industrial manufacturing). Forming operations where a blow torch is used therefore requires some expertise since no visual signs reveal how close the material is to melting. Even a relatively routine workshop procedure involving heating is complicated by the fact that aluminium, as opposed to steels, will melt without first turning red. Often, aluminium's sensitivity to heat must also be considered. Even the aluminium cylinder heads and crankcase of the Corvair, built as recently as the 1960s, earned a reputation for failure and stripping of threads in holes, even as large as spark plug holes, which is not seen in current aluminium cylinder heads.

An Audi engineer commented about the V12 engine, producing over 500 horsepower (370 kW), of an Auto Union race car of the 1930s which was recently restored by the Audi factory, that the aluminium alloy of which the engine was constructed would today be used only for lawn furniture and the like. Similarly, use of aluminium in automotive applications, particularly in engine parts which must survive in difficult conditions, has benefited from development over time. For instance, a high frequency of failure in many early aluminium bicycle frames in the 1970s resulted in just such a poor reputation; with a moment's reflection, however, the widespread use of aluminium components in the aerospace and automotive high performance industries, where huge stresses are undergone with vanishingly small failure rates, proves that properly built aluminium bicycle components should not be unusually unreliable, and this has subsequently proved to be the case. The strength and durability of aluminium varies widely, not only as a result of the components of the specific alloy, but also as a result of the particular manufacturing process; for this reason, it has from time to time gained a bad reputation.

Similarly, aluminium bicycle frames can be optimally designed so as to provide rigidity where required, yet have flexibility in terms of absorbing the shock of bumps from the road and not transmitting them to the rider. The aluminium chassis members and suspension parts of these cars have large overall dimensions for stiffness but are lightened by reducing cross-sectional area and removing unneeded metal; as a result, they are not only equally or more durable and stiff as the usual steel parts, but they possess an airy gracefulness which most people find attractive. The latest models of the Corvette automobile, among others, are a good example of redesigning parts to make best use of aluminium's advantages. The limit to this process is the increase in susceptibility to what is termed "buckling" failure, where the deviation of the force from any direction other than directly along the axis of the tubing causes folding of the walls of the tubing.

In this way, rigidity can be restored or even enhanced without increasing weight. Aluminium can best be used by redesigning the part to suit its characteristics; for instance making a bicycle of aluminium tubing which has an oversize diameter rather than thicker walls. To increase the rigidity by increasing the thickness of the walls of the tubing increases the weight proportionately, so that the advantages of lighter weight are lost as the rigidity is restored. Where failure is not an issue but excessive flex is undesirable due to requirements for precision of location or efficiency of transmission of power, simple replacement of steel tubing with similarly sized aluminium tubing will result in a degree of flex which is undesirable; for instance, the increased flex under operating loads caused by replacing steel bicycle frame tubing with aluminium tubing of identical dimensions will cause misalignment of the power-train as well as absorbing the operating force.

Therefore, although direct replacement of an iron or steel part with a duplicate made from aluminium may still give acceptable strength to withstand peak loads, the increased flexibility will cause three times more deflection in the part. The reduction by two thirds of the weight of an aluminium part compared to a similarly sized iron or steel part seems enormously attractive, but it should be noted that it is accompanied by a reduction by two thirds in the stiffness of the part. Improper use of aluminium can result in problems, particularly in contrast to iron or steel, which appear "better behaved" to the intuitive designer, mechanic, or technician. ^[1].

A brief historical overview of alloys and manufacturing technologies is given in Ref. Selecting the right alloy for a given application entails considerations of strength, ductility, formability, weldability and corrosion resistance to name a few. Alloy systems are classified by a number system (ANSI) or by names indicating their main alloying constituents (DIN and ISO). Aluminium alloys with a wide range of properties are used in engineering structures.

Aluminium is also a superconductor, with a superconducting critical temperature of 1.2 kelvins. Aluminium oxidises very energetically and as a result has found use in solid rocket fuels, thermite, and other pyrotechnic compositions. Synthetic ruby and sapphire are used in lasers for the production of coherent light. Aluminium oxide, alumina, is found naturally as corundum (rubies and sapphires), emery, and is used in glass making.

Some of the many uses for aluminium are in:.
. Telescope mirrors are also coated with a thin layer of aluminium, but are front coated to avoid internal reflections even though this makes the surface more susceptible to damage. In particular, nearly all modern mirrors are made using a thin reflective coating of aluminium on the back surface of a sheet of float glass.

These coatings form a thin layer of protective aluminium oxide that does not deteriorate as silver coatings do. When aluminium is evaporated in a vacuum it forms a coating that reflects both visible light and infrared. Aluminium alloys form vital components of aircraft and rockets as a result of their high strength to weight ratio. When combined with thermo-mechanical processing aluminium alloys display a marked improvement in mechanical properties.

Conversely, the term "alloy" in general use today usually means aluminium alloy. Pure aluminium is encountered only when corrosion resistance is more important than strength or hardness. Today almost all materials that claim to be aluminium are actually an alloy thereof. Pure aluminium has a low tensile strength, but readily forms alloys with many elements such as copper, zinc, magnesium, manganese and silicon (e.g.duralumin).

Whether measured in terms of quantity or value, the use of aluminium exceeds that of any other metal except iron, and it is important in virtually all segments of the world economy. It is the second most malleable metal (after gold) and the sixth most ductile. Aluminium mirror finish has the highest reflectance of any metal in the 200-400 nm (UV) , and the 3000-10000 nm (far IR) regions, while in the 400-700 nm visible range it is slightly outdone by silver, and in the 700-3000 (near IR) by silver, gold and copper. Aluminium is about one-third as dense as steel or copper; is malleable, ductile, and easily machined and cast; and has excellent corrosion resistance and durability due to the protective oxide layer.

Pure aluminium has a tensile strength of about 49 megapascals (MPa) and 700 MPa if it is formed into an alloy. Aluminium is nontoxic (as the metal), non-magnetic, and non-sparking. Aluminium is a soft and lightweight metal with a dull silvery appearance, due to a thin layer of oxidation that forms quickly when it is exposed to air. .

Structural components made from aluminium and its alloys are vital to the aerospace industry and very important in other areas of transportation and building in which light weight, durability, and strength are needed. Aluminium is used in many industries to make millions of different products and is very important to the world economy. Aluminium is found primarily as the ore bauxite and is remarkable for its resistance to oxidation (due to the phenomenon of passivation) and its light weight. It is a silvery and ductile member of the poor metal group of chemical elements.

Aluminium or aluminum (see the spelling section below) is the chemical element in the periodic table that has the symbol Al and atomic number 13. In the film Star Trek IV: The Voyage Home, Scotty devises the fictional material transparent aluminum. The aluminohalides have a similar structure. It has many uses in organic chemistry, particularly as a reducing agent.

It decomposes into lithium hydride, aluminium and hydrogen when heated, and is hydrolysed by water. Alumino-hydrides of the most electropositive elements are known, the most useful being lithium aluminium hydride, Li[AlH₄]. They have some uses in organic synthesis, for instance trimethylaluminium. Organo-metallic compounds of empirical formula AlR₃ exist and, if not also giant molecules, are at least dimers or trimers.

The other trihalides are dimeric, having a bridge-like structure. It is very inert. It consists of a giant molecule which sublimes without melting at 1291 °C. Aluminium fluoride, AlF₃, is made by treating the hydroxide with HF, or can be made from the elements.

It is polymorphic. Aluminium sulfide, Al₂S₃, may be prepared by passing hydrogen sulfide over aluminium powder. It exists in various crystalline forms. It is amphoteric, being both a very weak acid, and forming aluminates with alkalis.

Aluminium hydroxide may be prepared as a gelatinous precipitate by adding ammonia to an aqueous solution of an aluminium salt. It is almost insoluble in water. As a gemstone, its hardness is only exceeded by diamond, boron nitride and carborundum. Aluminium oxide, Al₂O₃, occurs naturally as corundum, and can be made by burning aluminium in oxygen or by heating the hydroxide, nitrate or sulfate.

Aluminium phosphide, AlP, is made similarly, and hydrolyses to give phosphine. It is hydrolysed by water to form ammonia and aluminium hydroxide. Aluminium nitride, AlN, can be made from the elements at 800 °C. The acetylide, Al₂(C₂)₃, is made by passing acetylene over heated aluminium.

The pale yellow crystals have a complex lattice structure, and react with water or dilute acids to give methane. Aluminium carbide, Al₄C₃ is made by heating a mixture of the elements above 1000 °C. It can also be prepared by the action of aluminium chloride on lithium hydride in ether solution, but cannot be isolated free from the solvent. It burns explosively in air.

Aluminium hydride, (AlH₃)_n, can be produced from trimethylaluminium and an excess of hydrogen. The salts of strong acids, such as nitrate, are stable and soluble in water, forming hydrates with at least six molecules of water of crystallization. The hydroxide is a weak base and aluminium salts of weak bases, such as carbonate, can't be prepared. Fajans rules show that the simple trivalent cation Al³⁺ is not expected to be found in anhydrous salts or binary compounds such as Al₂O₃.

Aluminium suboxide, AlO can be shown to be present when aluminium powder burns in oxygen. AlF, AlCl and AlBr exist in the gaseous phase when the tri-halide is heated with aluminium. The selenide is made in a parallel manner. It quickly disproportionates to the starting materials.

Al₂S can be made by heating Al₂S₃ with aluminium shavings at 1300 °C in a vacuum. Al₂O is made by heating the normal oxide, Al₂O₃, with silicon at 1800 °C in a vacuum. AlH is produced when aluminium is heated at 1500 °C in an atmosphere of hydrogen. Galvanic corrosion from the dissimilar metals increases the electrical resistance of the connection.

Pure aluminium has a tendency to "creep" under steady sustained pressure (to a greater degree as the temperature rises), again producing a degree of looseness in an initially tight connection. The greater coefficient of thermal expansion of aluminium, causes the wire to expand and contract relative to the dissimilar metal screw connection, eventually loosening the connection. Copper heat sinks are smaller although more expensive and harder to manufacture. Most modern computer CPU heat sinks are made of aluminium due to its ease of manufacture and good heat conductivity.

Anodised aluminium is more stable to further oxidation, and is used in various fields of construction. Aluminium flakes may also be included in undercoat paints, particularly wood primer — on drying, the flakes overlap to produce a water resistant barrier. Powdered aluminium, a commonly used silvering agent in paint. Super purity aluminium (SPA, 99.980% to 99.999% Al), used in electronics and CDs.

MKM steel and Alnico magnets, although non-magnetic itself. Machinery. Electrical transmission lines (aluminium conductors are half the weight of copper for equal conductivity and lower in price[1]). Consumer durable goods (appliances, cooking utensils, etc.).

Construction (windows, doors, siding, building wire, etc. Water treatment. Packaging (cans, foil, etc.). Transportation (automobiles, airplanes, trucks, railroad cars, marine vessels, etc.).