1.
Albany, Oregon
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Albany is the county seat of Linn County, and the 11th largest city in the State of Oregon. Albany is located in the Willamette Valley at the confluence of the Calapooia River and it is predominantly a farming and manufacturing city that settlers founded around 1848. As of the 2010 United States Census, the population of Albany was 50,158 and its population was estimated by the Portland Research Center to be 51,583 in 2013. Albany has a home rule charter, a government. The city provides the population access to over 30 parks and trails, a senior center. In addition to farming and manufacturing, the economy depends on retail trade, health care. In recent years the city has worked to revive the downtown shopping area, in the historic era, the area of the Willamette Valley that makes up modern-day Albany was inhabited by one of the tribes of the Kalapuya a Penutian-speaking, Native American people. The Kalapuya had named the area Takenah, a Kalapuyan word used to describe the deep pool at the confluence of the Calapooia, a variation of the place name can also be written as Tekenah. The Kalapuya population in the valley was between 4,000 and 20,000 before contact with Europeans, but they suffered high mortality from new diseases introduced shortly afterward. The tribes were decimated by an epidemic that raged through the Pacific Northwest in 1782–83. A malaria outbreak swept through the region between 1830 and 1833 and it is estimated that as many as 90 percent of the Kalapuya population died during this period. That, coupled with the treaties signed during the 1850s by the Kalapuya to cede land to the United States, the first European American settler arrived in 1845, Abner Hackleman was a farmer from Iowa. Taking up a claim for himself, Hackleman asked Hiram N. Smead to hold another for him until his son arrived from Iowa. In 1846, a year after arriving in Oregon, Hackleman died while returning to Iowa to fetch his family. In 1847 a pair of brothers, Walter and Thomas Monteith, settled in the area, after traveling by ox team along the Oregon Trail from their native state of New York. They were a family of prominence in the area, in 1848, they bought a claim of 320 acres from Hiram Smead for $400. They named the city Albany after their hometown of Albany in New York, during the same period, Hacklemans son Abram reached his fathers original land claim and built a log house in an oak grove still known as Hacklemans Grove. He later built a house, which stands at the corner of Fifth
2.
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
3.
Metal
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A metal is a material that is typically hard, opaque, shiny, and has good electrical and thermal conductivity. Metals are generally malleable—that is, they can be hammered or pressed permanently out of shape without breaking or cracking—as well as fusible and ductile, about 91 of the 118 elements in the periodic table are metals, the others are nonmetals or metalloids. Some elements appear in both metallic and non-metallic forms, astrophysicists use the term metal to collectively describe all elements other than hydrogen and helium, the simplest two, in a star. The star fuses smaller atoms, mostly hydrogen and helium, to larger ones over its lifetime. In that sense, the metallicity of an object is the proportion of its matter made up of all chemical elements. Many elements and compounds that are not normally classified as metals become metallic under high pressures, the atoms of metallic substances are typically arranged in one of three common crystal structures, namely body-centered cubic, face-centered cubic, and hexagonal close-packed. In bcc, each atom is positioned at the center of a cube of eight others, in fcc and hcp, each atom is surrounded by twelve others, but the stacking of the layers differs. Some metals adopt different structures depending on the temperature, atoms of metals readily lose their outer shell electrons, resulting in a free flowing cloud of electrons within their otherwise solid arrangement. This provides the ability of metallic substances to easily transmit heat, while this flow of electrons occurs, the solid characteristic of the metal is produced by electrostatic interactions between each atom and the electron cloud. This type of bond is called a metallic bond, Metals are usually inclined to form cations through electron loss, reacting with oxygen in the air to form oxides over various timescales. Examples,4 Na + O2 →2 Na2O2 Ca + O2 →2 CaO4 Al +3 O2 →2 Al2O3, the transition metals are slower to oxidize because they form a passivating layer of oxide that protects the interior. Others, like palladium, platinum and gold, do not react with the atmosphere at all, some metals form a barrier layer of oxide on their surface which cannot be penetrated by further oxygen molecules and thus retain their shiny appearance and good conductivity for many decades. The oxides of metals are generally basic, as opposed to those of nonmetals, exceptions are largely oxides with very high oxidation states such as CrO3, Mn2O7, and OsO4, which have strictly acidic reactions. Painting, anodizing or plating metals are good ways to prevent their corrosion, however, a more reactive metal in the electrochemical series must be chosen for coating, especially when chipping of the coating is expected. Water and the two form an electrochemical cell, and if the coating is less reactive than the coatee. Metals in general have high conductivity, high thermal conductivity. Typically they are malleable and ductile, deforming under stress without cleaving, in terms of optical properties, metals are shiny and lustrous. Sheets of metal beyond a few micrometres in thickness appear opaque, although most metals have higher densities than most nonmetals, there is wide variation in their densities, lithium being the least dense solid element and osmium the densest
4.
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
5.
Ceramic
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A ceramic is an inorganic, non-metallic, solid material comprising metal, non-metal or metalloid atoms primarily held in ionic and covalent bonds. This article gives an overview of ceramic materials from the point of view of materials science, the crystallinity of ceramic materials ranges from highly oriented to semi-crystalline, vitrified, and often completely amorphous. Most often, fired ceramics are either vitrified or semi-vitrified as is the case with earthenware, stoneware, varying crystallinity and electron consumption in the ionic and covalent bonds cause most ceramic materials to be good thermal and electrical insulators. With such a range of possible options for the composition/structure of a ceramic, the breadth of the subject is vast. Many composites, such as fiberglass and carbon fiber, while containing ceramic materials, are not considered to be part of the ceramic family. The earliest ceramics made by humans were pottery objects or figurines made from clay, either by itself or mixed with materials like silica, hardened, sintered. Later ceramics were glazed and fired to create smooth, colored surfaces, decreasing porosity through the use of glassy, ceramics now include domestic, industrial and building products, as well as a wide range of ceramic art. In the 20th century, new materials were developed for use in advanced ceramic engineering. The word ceramic comes from the Greek word κεραμικός, of pottery or for pottery, from κέραμος, potters clay, tile, the earliest known mention of the root ceram- is the Mycenaean Greek ke-ra-me-we, workers of ceramics, written in Linear B syllabic script. The word ceramic may be used as an adjective to describe a material, product or process, or it may be used as a noun, either singular, or, more commonly, as the plural noun ceramics. A ceramic material is an inorganic, non-metallic, often crystalline oxide, nitride or carbide material, some elements, such as carbon or silicon, may be considered ceramics. Ceramic materials are brittle, hard, strong in compression, weak in shearing and they withstand chemical erosion that occurs in other materials subjected to acidic or caustic environments. Ceramics generally can withstand high temperatures, such as temperatures that range from 1,000 °C to 1,600 °C. Glass is often not considered a ceramic because of its amorphous character. However, glassmaking involves several steps of the process and its mechanical properties are similar to ceramic materials. Traditional ceramic raw materials include minerals such as kaolinite, whereas more recent materials include aluminium oxide. The modern ceramic materials, which are classified as advanced ceramics, include silicon carbide, both are valued for their abrasion resistance, and hence find use in applications such as the wear plates of crushing equipment in mining operations. Advanced ceramics are used in the medicine, electrical, electronics industries. Crystalline ceramic materials are not amenable to a range of processing
6.
Prototype
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A prototype is an early sample, model, or release of a product built to test a concept or process or to act as a thing to be replicated or learned from. It is a used in a variety of contexts, including semantics, design, electronics. A prototype is used to evaluate a new design to enhance precision by system analysts. Prototyping serves to provide specifications for a real, working system rather than a theoretical one, in some design workflow models, creating a prototype is the step between the formalization and the evaluation of an idea. The word prototype derives from the Greek πρωτότυπον prototypon, primitive form, neutral of πρωτότυπος prototypos, original, primitive, from πρῶτος protos, first and τύπος typos, a Working Prototype represents all or nearly all of the functionality of the final product. A Visual Prototype represents the size and appearance, but not the functionality, a User Experience Prototype represents enough of the appearance and function of the product that it can be used for user research. A Functional Prototype captures both function and appearance of the design, though it may be created with different techniques. A Paper Prototype is a printed or hand-drawn representation of the interface of a software product. In some cases, the final production materials may still be undergoing development themselves, process - Mass-production processes are often unsuitable for making a small number of parts, so prototypes may be made using different fabrication processes than the final product. Differences in fabrication process may lead to differences in the appearance of the prototype as compared to the final product, verification - The final product may be subject to a number of quality assurance tests to verify conformance with drawings or specifications. These tests may involve custom inspection fixtures, statistical sampling methods, prototypes are generally made with much closer individual inspection and the assumption that some adjustment or rework will be part of the fabrication process. Prototypes may also be exempted from some requirements that apply to the final product. Engineers and prototype specialists will attempt to minimize the impact of these differences on the role for the prototype. Engineers and prototyping specialists seek to understand the limitations of prototypes to exactly simulate the characteristics of their intended design and it is important to realize that by their very definition, prototypes will represent some compromise from the final production design. Due to differences in materials, processes and design fidelity, it is possible that a prototype may fail to perform acceptably whereas the design may have been sound. In general, it can be expected that individual prototype costs will be greater than the final production costs due to inefficiencies in materials. Prototypes are also used to revise the design for the purposes of reducing costs through optimization and it is possible to use prototype testing to reduce the risk that a design may not perform as intended, however prototypes generally cannot eliminate all risk. As an alternative, rapid prototyping or rapid application development techniques are used for the prototypes, which implement part
7.
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
8.
Waste
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Waste and wastes are unwanted or unusable materials. Waste is any substance which is discarded after use, or it is worthless, defective. Examples include municipal solid waste, hazardous waste, wastewater, radioactive waste, according to the Basel Convention on the Control of Transboundary Movements of Hazardous Wastes and Their Disposal of 1989, Art. 2, Wastes are substance or objects, which are disposed of or are intended to be disposed of or are required to be disposed of by the provisions of national law. Wastes may be generated during the extraction of raw materials, the processing of raw materials into intermediate and final products, the consumption of final products, residuals recycled or reused at the place of generation are excluded. Under the Waste Framework Directive 2008/98/EC, Art,3, the European Union defines waste as an object the holder discards, intends to discard or is required to discard. For a more structural description of the Waste Directive, see the European Commissions summary and it is most commonly measured by size or weight, and there is a stark difference between the two. For example, organic waste is much heavier when it is wet, on a global scale it is difficult to report waste because countries have different definitions of waste and what falls into waste categories, as well as different ways of reporting. Based on incomplete reports from its parties, the Basel Convention estimated 338 million tonnes of waste was generated in 2001, for the same year, OECD estimated 4 billion tonnes from its member countries. Toxic waste materials can contaminate surface water, groundwater, soil, and air which causes problems for humans, other species. Waste treatment and disposal produces significant green house gas emissions, notably methane, Waste management is a significant environmental justice issue. Many of the environmental burdens cited above are often borne by marginalized groups, such as racial minorities, women. NIMBY is the opposition of residents to a proposal for a new development because it is close to them, however, the need for expansion and siting of waste treatment and disposal facilities is increasing worldwide. Environmental policies such as pay as you throw can reduce the cost of management, Waste recovery can curb economic costs because it avoids extracting raw materials and often cuts transportation costs. Economic assessment of municipal waste management systems – case studies using a combination of life-cycle assessment, the location of waste treatment and disposal facilities often reduces property values due to noise, dust, pollution, unsightliness, and negative stigma. The informal waste sector consists mostly of waste pickers who scavenge for metals, glass, plastic, textiles, and other materials and then trade them for a profit. This sector can significantly alter or reduce waste in a system, but other negative economic effects come with the disease, poverty, exploitation. Resource recovery is the retrieval of recyclable waste, which was intended for disposal and it is the processing of recyclables to extract or recover materials and resources, or convert to energy
9.
Lewis & Clark College
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Lewis & Clark College is a private liberal arts college located in Portland, Oregon. It has an undergraduate College of Arts and Sciences, a School of Law, Lewis & Clark is a member of the Annapolis Group of colleges with athletic programs competing in the National Collegiate Athletic Associations Division III Northwest Conference. Just over 2,000 students attend the undergraduate College of Arts and Sciences, the School of Law is best known for its environmental law program, while the Graduate School of Education & Counseling is active in community engagement and social justice. Today, the three schools and their supporting offices occupy a campus of 137 acres, centered on the M. Lloyd Frank Estate on Palatine Hill in the Collins View neighborhood of Southwest Portland. To this end the Presbyterian church incorporated Albany Academy in 1858, within a decade of its founding, Albany Academy began to focus more exclusively on higher education, changing its official name to the Albany Collegiate Institution in 1866. Unlike most Oregon colleges of the pioneer-era, the college has been coeducational since the first class, the early campus of 7 acres in Albany was situated on land donated by the Monteith family. In 1892, the school building was enlarged, and in 1925 the school relocated south of Albany where it remained until 1937. Albany College established a college to the north in Portland in 1934. The campus grounds later became home to the federal governments Albany Research Center, in 1942 the college trustees acquired the Lloyd Frank “Fir Acres” estate in southwest Portland, and the school name was changed to Lewis & Clark College. The original school mascot, the Pirates, was changed to the Pioneers in 1946, the three schools of the college include the College of Arts and Sciences, the Law School, and the Graduate School of Education and Counseling. Lewis & Clark has nationally regarded programs in Biology, International Affairs, Psychology, Foreign Languages, the college has held two worldwide symphonic festivals in the past five years with professional-level performances in Dublin and the Greek islands. Lewis & Clark is also known for its active and diverse overseas study program, the college offers approximately 36 programs in various countries, and since the 1960s, more than 60% of all Lewis & Clark undergraduates have studied abroad. For a small liberal arts college, Lewis & Clarks overseas offerings are impressive in both breadth and scope, there are, for example seven discrete programs in Spanish-speaking countries. Lewis & Clark is also one of the few U. S. institutions with a program in Cuba. For the Class of 2018, Lewis & Clark received 6,244 applications, accepted 4,160 and enrolled 564. In terms of rank, of the 41% of high school seniors who submitted it, 38% of enrolled freshmen were in the top tenth of their high school classes. The middle 50% range of SAT scores for the enrolled freshmen was 610-710 for critical reading, 580-670 for math, the average high school Grade Point Average GPA of enrolled freshmen was 3.91. The 2017 annual ranking of U. S. News & World Report categorizes Lewis & Clark as more selective and ranks it tied for the 87th best liberal arts college in the nation
10.
United States Atomic Energy Commission
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President Harry S. Truman signed the McMahon/Atomic Energy Act on August 1,1946, transferring the control of atomic energy from military to civilian hands, effective from January 1,1947. This shift gave the first members of the AEC complete control of the plants, laboratories, equipment, during its initial establishment and subsequent operationalization, the AEC played a key role in the institutional development of Ecosystem ecology. Specifically, it provided financial resources, allowing for ecological research to take place. Perhaps even more importantly, it enabled ecologists with a range of groundbreaking techniques for the completion of their research. In the late 1950s and early 1960s, the AEC also approved funding for numerous projects in the Arctic and near-Arctic. These projects were designed to examine the effects of energy upon the environment and were a part of the Commission’s attempt at creating peaceful applications of atomic energy. By 1974, the AECs regulatory programs had come under strong attack that Congress decided to abolish the agency. On August 4,1977, President Jimmy Carter signed into law The Department of Energy Organization Act of 1977, at the same time, the McMahon Act which created the AEC also gave it unprecedented powers of regulation over the entire field of nuclear science and technology. President Truman appointed David Lilienthal as the first Chairman of the AEC, Congress gave the new civilian Commission extraordinary power and considerable independence to carry out its mission. To provide the Commission exceptional freedom in hiring scientists and professionals, the National Laboratory system was established from the facilities created under the Manhattan Project. Argonne National Laboratory was one of the first laboratories authorized under this legislation as a facility dedicated to fulfilling the new Commissions mission. The Commissions first order of business was to inspect the scattered empire of plants, the AEC was furthermore in charge of developing the United States nuclear arsenal, taking over these responsibilities from the wartime Manhattan Project. It also implemented the program to develop the hydrogen bomb. It began a program of nuclear testing both in the Pacific Proving Grounds and at the continental Nevada Test Site. While it also supported much basic research, the vast majority of its budget was devoted to atomic weapons development. Within the AEC, high-level scientific and technical advice was provided by the General Advisory Committee, in its early years, the GAC provided a number of controversial decisions, notably its decision against building the hydrogen bomb in 1949. As a result, Senator Brien McMahon influenced the decision not to reappoint J. Robert Oppenheimer to the GAC in 1952 after his six-year statutory term expired. David Lilienthal, then AEC Chair, agreed with Oppenheimer and opposed a program to build the hydrogen bomb ahead of any other nation
11.
USS Nautilus (SSN-571)
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USS Nautilus was the worlds first operational nuclear-powered submarine. The vessel was the first submarine to complete a submerged transit of the North Pole on 3 August 1958, in operation, she revealed a number of limitations in her design and construction. This information was used to improve subsequent submarines, Nautilus was decommissioned in 1980 and designated a National Historic Landmark in 1982. The submarine has been preserved as a ship in Groton, Connecticut. On 12 December 1951 the US Department of the Navy announced that the submarine would be called Nautilus, the boat carried the hull number SSN-571. The Nautilus benefited from the GUPPY improvements to the American Gato-, Balao-, nautiluss keel was laid at General Dynamics Electric Boat Division in Groton, Connecticut by Harry S. Truman on 14 June 1952. She was christened on 21 January 1954 and launched into the Thames River, nuclear power had the crucial advantage in submarine propulsion because it is a zero-emission process that consumes no air. This design is the basis for all of the US nuclear-powered submarine and surface combat ships. The first actual prototype was constructed and tested by the Argonne National Laboratory in 1953 at the S1W facility, part of the National Reactor Testing Station in Idaho. Nautilus ships patch was designed by The Walt Disney Company, and her wardroom currently displays a set of made of zirconium. Following her commissioning, Nautilus remained dockside for further construction and testing, at 11 a. m. on 17 January 1955 she put to sea for the first time and signaled her historic message, Underway on nuclear power. On 10 May, she headed south for shakedown, submerged throughout, she traveled 1,100 nautical miles from New London to San Juan, Puerto Rico and covered 1,200 nautical miles in less than ninety hours. At the time, this was the longest submerged cruise by a submarine, from 1955 to 1957, Nautilus continued to be used to investigate the effects of increased submerged speeds and endurance. The improvements rendered the progress made in anti-submarine warfare during World War II virtually obsolete, on 4 February 1957, Nautilus logged her 60, 000th nautical mile, matching the endurance of her namesake, the fictional Nautilus described in Jules Vernes novel Twenty Thousand Leagues Under The Sea. Nautilus returned to New London, Connecticut, on 21 July and she arrived back at New London on 28 October, underwent upkeep, and then conducted coastal operations until the spring. On 25 April 1958, Nautilus was underway again for the West Coast, now commanded by Commander William R. Anderson, USN. Stopping at San Diego, San Francisco, and Seattle, she began her history-making polar transit, operation Sunshine, on 19 June she entered the Chukchi Sea, but was turned back by deep drift ice in those shallow waters. On 28 June she arrived at Pearl Harbor to await better ice conditions, by 23 July 1958 her wait was over, and she set a course northward
12.
Titanium
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Titanium is a chemical element with symbol Ti and atomic number 22. It is a transition metal with a silver color, low density. Titanium is resistant to corrosion in sea water, aqua regia, titanium was discovered in Cornwall, Great Britain, by William Gregor in 1791, and it is named by Martin Heinrich Klaproth for the Titans of Greek mythology. The metal is extracted from its principal mineral ores by the Kroll, the most common compound, titanium dioxide, is a popular photocatalyst and is used in the manufacture of white pigments. Other compounds include titanium tetrachloride, a component of smoke screens and catalysts, and titanium trichloride, the two most useful properties of the metal are corrosion resistance and strength-to-density ratio, the highest of any metallic element. In its unalloyed condition, titanium is as strong as some steels, there are two allotropic forms and five naturally occurring isotopes of this element, 46Ti through 50Ti, with 48Ti being the most abundant. Although they have the number of valence electrons and are in the same group in the periodic table. As a metal, titanium is recognized for its high strength-to-weight ratio and it is a strong metal with low density that is quite ductile, lustrous, and metallic-white in color. The relatively high melting point makes it useful as a refractory metal and it is paramagnetic and has fairly low electrical and thermal conductivity. Commercial grades of titanium have ultimate tensile strength of about 434 MPa, equal to that of common, low-grade steel alloys, titanium is 60% denser than aluminium, but more than twice as strong as the most commonly used 6061-T6 aluminium alloy. Certain titanium alloys achieve tensile strengths of over 1400 MPa, however, titanium loses strength when heated above 430 °C. Titanium is not as hard as some grades of heat-treated steel, it is non-magnetic, machining requires precautions, because the material might gall unless sharp tools and proper cooling methods are used. Like steel structures, those made from titanium have a limit that guarantees longevity in some applications. The metal is an allotrope of an hexagonal α form that changes into a body-centered cubic β form at 882 °C. The specific heat of the α form increases dramatically as it is heated to this transition temperature but then falls, similar to zirconium and hafnium, an additional omega phase exists, which is thermodynamically stable at high pressures, but metastable at ambient pressures. This phase is usually hexagonal or trigonal and can be considered to be due to a soft longitudinal acoustic phonon of the β phase causing collapse of planes of atoms, like aluminium and magnesium, titanium metal and its alloys oxidize immediately upon exposure to air. Titanium readily reacts with oxygen at 1,200 °C in air and it is, however, slow to react with water and air at ambient temperatures because it forms a passive oxide coating that protects the bulk metal from further oxidation. When it first forms, this layer is only 1–2 nm thick but continues to grow slowly
