|
Low-background Steel
Low-background steel, also known as pre-war steel, is any steel produced prior to the detonation of the first nuclear bombs in the 1940s and 1950s. Typically sourced from shipwrecks and other steel artifacts of this era, it is often used for modern particle detectors because more modern steel is contaminated with traces of nuclear fallout. Since the cessation of atmospheric nuclear testing, background radiation has decreased to very near natural levels, making special low-background steel no longer necessary for most radiation-sensitive applications, as brand-new steel now has a low enough radioactive signature that it can generally be used in such applications. However, some demand remains for the most radiation-sensitive applications, such as Geiger counters and sensing equipment aboard spacecraft, and World War II-era shipwrecks near in the Java Sea and western South China Sea are often illegally scavenged for low-background steel. Radionuclide contamination From 1856 until t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steel
Steel is an alloy made up of iron with added carbon to improve its strength and fracture resistance compared to other forms of iron. Many other elements may be present or added. Stainless steels that are corrosion- and oxidation-resistant typically need an additional 11% chromium. Because of its high tensile strength and low cost, steel is used in buildings, infrastructure, tools, ships, trains, cars, machines, electrical appliances, weapons, and rockets. Iron is the base metal of steel. Depending on the temperature, it can take two crystalline forms (allotropic forms): body-centred cubic and face-centred cubic. The interaction of the allotropes of iron with the alloying elements, primarily carbon, gives steel and cast iron their range of unique properties. In pure iron, the crystal structure has relatively little resistance to the iron atoms slipping past one another, and so pure iron is quite ductile, or soft and easily formed. In steel, small amounts of carbon, other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bessemer Process
The Bessemer process was the first inexpensive industrial process for the mass production of steel from molten pig iron before the development of the open hearth furnace. The key principle is steelmaking, removal of impurities from the iron by oxidation with air being blown through the molten iron. The oxidation also raises the temperature of the iron mass and keeps it molten. Related Decarburization, decarburizing with air processes had been used outside Europe for hundreds of years, but not on an industrial scale. One such process (similar to puddling (metallurgy), puddling) was known in the 11th century in East Asia, where the scholar Shen Kuo of that era described its use in the Chinese iron and steel industry. In the 17th century, accounts by European travelers detailed its possible use by the Japanese. The modern process is named after its inventor, the Englishman Henry Bessemer, who took out a patent on the process in 1856. The process was said to be independently discover ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United Nations Scientific Committee On The Effects Of Atomic Radiation
The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) was set up by resolution of the United Nations General Assembly in 1955. 21 states are designated to provide scientists to serve as members of the committee which holds formal meetings (sessions) annually and submits a report to the General Assembly. The organisation has no power to set radiation standards nor to make recommendations in regard to nuclear testing. It was established solely to "define precisely the present exposure of the population of the world to ionizing radiation." A small secretariat, located in Vienna and functionally linked to the UN Environment Program, organizes the annual sessions and manages the preparation of documents for the committee's scrutiny. Function UNSCEAR issues major public reports on ''Sources and Effects of Ionizing Radiation'' from time to time. As of 2017, there have been 28 major publications from 1958 to 2017. The reports are all available from the UNS ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Partial Nuclear Test Ban Treaty
The Partial Test Ban Treaty (PTBT) is the abbreviated name of the 1963 Treaty Banning Nuclear Weapon Tests in the Atmosphere, in Outer Space and Under Water, which prohibited all test detonations of nuclear weapons except for those conducted underground. It is also abbreviated as the Limited Test Ban Treaty (LTBT) and Nuclear Test Ban Treaty (NTBT), though the latter may also refer to the Comprehensive Nuclear-Test-Ban Treaty (CTBT), which succeeded the PTBT for ratifying parties. Negotiations initially focused on a comprehensive ban, but that was abandoned because of technical questions surrounding the detection of underground tests and Soviet concerns over the intrusiveness of proposed verification methods. The impetus for the test ban was provided by rising public anxiety over the magnitude of nuclear tests, particularly tests of new thermonuclear weapons (hydrogen bombs), and the resulting nuclear fallout. A test ban was also seen as a means of slowing nuclear proliferati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sievert
The sievert (symbol: SvNot be confused with the sverdrup or the svedberg, two non-SI units that sometimes use the same symbol.) is a unit in the International System of Units (SI) intended to represent the stochastic health risk of ionizing radiation, which is defined as the probability of causing radiation-induced cancer and genetic damage. The sievert is important in dosimetry and radiation protection. It is named after Rolf Maximilian Sievert, a Swedish medical physicist renowned for work on radiation dose measurement and research into the biological effects of radiation. The sievert is used for radiation dose quantities such as equivalent dose and effective dose (radiation), effective dose, which represent the risk of external radiation from sources outside the body, and committed dose, which represents the risk of internal irradiation due to inhaled or ingested radioactive substances. According to the International Commission on Radiological Protection (ICRP) one sievert r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anthropogenic Hazard
Anthropogenic hazards are hazards caused by human action or inaction. They are contrasted with natural hazards. Anthropogenic hazards may adversely affect humans, other organisms, biomes, and ecosystems. They can even cause an omnicide. The frequency and severity of hazards are key elements in some risk analysis methodologies. Hazards may also be described in relation to the impact that they have. A hazard only exists if there is a pathway to exposure. As an example, the center of the earth consists of molten material at very high temperatures which would be a severe hazard if contact was made with the core. However, there is no feasible way of making contact with the core, therefore the center of the earth currently poses no hazard. Anthropogenic hazards can be grouped into societal hazards (criminality, civil disorder, terrorism, war, industrial hazards, engineering hazards, power outage, fire), hazards caused by transportation and environmental hazards. Societal hazards ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cobalt-60
Cobalt-60 (60Co) is a synthetic radioactive isotope of cobalt with a half-life of 5.2713 years. It is produced artificially in nuclear reactors. Deliberate industrial production depends on neutron activation of bulk samples of the monoisotopic and mononuclidic cobalt isotope . (PDF also located aCanadian Nuclear FAQ Measurable quantities are also produced as a by-product of typical nuclear power plant operation and may be detected externally when leaks occur. In the latter case (in the absence of added cobalt) the incidentally produced is largely the result of multiple stages of neutron activation of iron isotopes in the reactor's steel structures via the creation of its precursor. The simplest case of the latter would result from the activation of . undergoes beta decay to the stable isotope nickel-60 (). The activated nickel nucleus emits two gamma rays with energies of 1.17 and 1.33 MeV, hence the overall equation of the nuclear reaction (activation and decay) is: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxygen
Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as well as with other compounds. Oxygen is Earth's most abundant element, and after hydrogen and helium, it is the third-most abundant element in the universe. At standard temperature and pressure, two atoms of the element bind to form dioxygen, a colorless and odorless diatomic gas with the formula . Diatomic oxygen gas currently constitutes 20.95% of the Earth's atmosphere, though this has changed considerably over long periods of time. Oxygen makes up almost half of the Earth's crust in the form of oxides.Atkins, P.; Jones, L.; Laverman, L. (2016).''Chemical Principles'', 7th edition. Freeman. Many major classes of organic molecules in living organisms contain oxygen atoms, such as proteins, nucleic acids, carbohydrates, and fats, as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basic Oxygen Steelmaking
Basic oxygen steelmaking (BOS, BOP, BOF, or OSM), also known as Linz-Donawitz steelmaking or the oxygen converter processBrock and Elzinga, p. 50. is a method of primary steelmaking in which carbon-rich molten pig iron is made into steel. Blowing oxygen through molten pig iron lowers the carbon content of the alloy and changes it into low-carbon steel. The process is known as ''basic'' because fluxes of burnt lime or dolomite, which are chemical '' bases'', are added to promote the removal of impurities and protect the lining of the converter. The process was invented in 1948 by Swiss engineer Robert Durrer and commercialized in 1952–1953 by the Austrian steelmaking company VOEST and ÖAMG. The LD converter, named after the Austrian towns Linz and Donawitz (a district of Leoben) is a refined version of the Bessemer converter where blowing of air is replaced with blowing oxygen. It reduced capital cost of the plants and smelting time, and increased labor productivity. Between 19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pig Iron
Pig iron, also known as crude iron, is an intermediate product of the iron industry in the production of steel which is obtained by smelting iron ore in a blast furnace. Pig iron has a high carbon content, typically 3.8–4.7%, along with silica and other constituents of dross, which makes it brittle and not useful directly as a material except for limited applications. The traditional shape of the molds used for pig iron ingots is a branching structure formed in sand, with many individual ingots at right angles to a central channel or "runner", resembling a litter of piglets being nursed by a sow. When the metal had cooled and hardened, the smaller ingots (the "pigs") were simply broken from the runner (the "sow"), hence the name "pig iron". As pig iron is intended for remelting, the uneven size of the ingots and the inclusion of small amounts of sand cause only insignificant problems considering the ease of casting and handling them. History Smelting and producing wroug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bessemer Converter
The Bessemer process was the first inexpensive industrial process for the mass production of steel from molten pig iron before the development of the open hearth furnace. The key principle is removal of impurities from the iron by oxidation with air being blown through the molten iron. The oxidation also raises the temperature of the iron mass and keeps it molten. Related decarburizing with air processes had been used outside Europe for hundreds of years, but not on an industrial scale. One such process (similar to puddling) was known in the 11th century in East Asia, where the scholar Shen Kuo of that era described its use in the Chinese iron and steel industry. In the 17th century, accounts by European travelers detailed its possible use by the Japanese. The modern process is named after its inventor, the Englishman Henry Bessemer, who took out a patent on the process in 1856. The process was said to be independently discovered in 1851 by the American inventor William Kelly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
History Of The Modern Steel Industry
History (derived ) is the systematic study and the documentation of the human activity. The time period of event before the invention of writing systems is considered prehistory. "History" is an umbrella term comprising past events as well as the memory, discovery, collection, organization, presentation, and interpretation of these events. Historians seek knowledge of the past using historical sources such as written documents, oral accounts, art and material artifacts, and ecological markers. History is not complete and still has debatable mysteries. History is also an academic discipline which uses narrative to describe, examine, question, and analyze past events, and investigate their patterns of cause and effect. Historians often debate which narrative best explains an event, as well as the significance of different causes and effects. Historians also debate the nature of history as an end in itself, as well as its usefulness to give perspective on the problems of the p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> History Of The Modern Steel Industry")