|
OSU Radiation Center
The Oregon State University Radiation Center (OSURC) is a research facility that houses a nuclear reactor at Oregon State University (OSU) in Corvallis, Oregon, United States. The Oregon State TRIGA Reactor (OSTR) serves the research needs of the OSU nuclear engineering department along with other departments (notably medical applications). About 70% of the research projects at the OSU Radiation Center use the reactor. Reactor overview The radiation center is located on the west side of the OSU campus, across the street from the United States Environmental Protection Agency, Environmental Protection Agency (EPA) offices and about half a mile from Reser Stadium. The reactor is a Mark II TRIGA reactor with a maximum thermal output of 1.1 MW and can be pulsed up to a power of 3000 MW for a very short time. The fuel is low enriched uranium. Operation began in 1967. The reactor supported 96 academic courses in 1999. These courses were in chemistry, civil engineering, chemical engi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
OSU Radiation Center
The Oregon State University Radiation Center (OSURC) is a research facility that houses a nuclear reactor at Oregon State University (OSU) in Corvallis, Oregon, United States. The Oregon State TRIGA Reactor (OSTR) serves the research needs of the OSU nuclear engineering department along with other departments (notably medical applications). About 70% of the research projects at the OSU Radiation Center use the reactor. Reactor overview The radiation center is located on the west side of the OSU campus, across the street from the United States Environmental Protection Agency, Environmental Protection Agency (EPA) offices and about half a mile from Reser Stadium. The reactor is a Mark II TRIGA reactor with a maximum thermal output of 1.1 MW and can be pulsed up to a power of 3000 MW for a very short time. The fuel is low enriched uranium. Operation began in 1967. The reactor supported 96 academic courses in 1999. These courses were in chemistry, civil engineering, chemical engi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marine Propulsion
Marine propulsion is the mechanism or system used to generate thrust to move a watercraft through water. While paddles and sails are still used on some smaller boats, most modern ships are propelled by mechanical systems consisting of an electric motor or internal combustion engine driving a propeller, or less frequently, in pump-jets, an impeller. Marine engineering is the discipline concerned with the engineering design process of marine propulsion systems. Human-powered paddles and oars, and later, sails were the first forms of marine propulsion. Rowed galleys, some equipped with sail, played an important early role in early human seafaring and warfares. The first advanced mechanical means of marine propulsion was the marine steam engine, introduced in the early 19th century. During the 20th century it was replaced by two-stroke or four-stroke diesel engines, outboard motors, and gas turbine engines on faster ships. Marine nuclear reactors, which appeared in the 1950s, pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neutron Reflector
A neutron reflector is any material that reflects neutrons. This refers to elastic scattering rather than to a specular reflection. The material may be graphite, beryllium, steel, tungsten carbide, gold, or other materials. A neutron reflector can make an otherwise subcritical mass of fissile material critical, or increase the amount of nuclear fission that a critical or supercritical mass will undergo. Such an effect was exhibited twice in accidents involving the Demon Core, a subcritical plutonium pit that went critical in two separate fatal incidents when the pit's surface was momentarily surrounded by too much neutron reflective material. Nuclear reactors In a uranium graphite chain reacting pile, the critical size may be considerably reduced by surrounding the pile with a layer of graphite, since such an envelope reflects many neutrons back into the pile. To obtain a 30-year life span, the SSTAR nuclear reactor design calls for a moveable neutron reflector to be pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lazy Susan
A Lazy Susan is a turntable (rotating tray) placed on a table or countertop to aid in distributing food. Lazy Susans may be made from a variety of materials but are usually glass, wood, or plastic. They are circular and placed in the centre of a table to share dishes easily among diners. Although they are common in Chinese restaurants, the Lazy Susan is a Western invention. Owing to the nature of Chinese cuisine, especially dim sum, they are common at formal Chinese restaurants both in mainland China and abroad. In Chinese, they are known as ( t. 餐桌轉盤) ( p ''cānzhuō zhuànpán'') or "dinner-table turntables". History It is likely that the explanation of the term Lazy Susan has been lost to history. Quinion, Michael. ''World Wide Words'':lazy Susan. 24 Apr 2010. Accessed 11 Aug 2013.Lazy Susan.What’s in a name? The origins of Lazy Susan. 27 Sep 2010. Accessed 11 Aug 2013. Folk etymologies claim it as an American invention. According to lore, Thomas Jefferson ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neutron Flux
The neutron flux, φ, is a scalar quantity used in nuclear physics and nuclear reactor physics. It is the total length travelled by all free neutrons per unit time and volume. Equivalently, it can be defined as the number of neutrons travelling through a small sphere of radius R in a time interval, divided by \pi R^2 (the cross section of the sphere) and by the time interval. The usual unit is cm−2s−1 (neutrons per centimeter squared per second). The neutron fluence is defined as the neutron flux integrated over a certain time period, so its usual unit is cm−2 (neutrons per centimeter squared). An older term used instead of cm−2 was n.v.t. (neutrons, velocity, time). Natural neutron flux Neutron flux in asymptotic giant branch stars and in supernovae is responsible for most of the natural nucleosynthesis producing elements heavier than iron. In stars there is a relatively low neutron flux on the order of 105 to 1011 cm−2 s−1, resulting in nucleosynthesis by the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neutron Activation
Neutron activation is the process in which neutron radiation induces radioactivity in materials, and occurs when atomic nuclei capture free neutrons, becoming heavier and entering excited states. The excited nucleus decays immediately by emitting gamma rays, or particles such as beta particles, alpha particles, fission products, and neutrons (in nuclear fission). Thus, the process of neutron capture, even after any intermediate decay, often results in the formation of an unstable activation product. Such radioactive nuclei can exhibit half-lives ranging from small fractions of a second to many years. Neutron activation is the only common way that a stable material can be induced into becoming intrinsically radioactive. All naturally occurring materials, including air, water, and soil, can be induced (activated) by neutron capture into some amount of radioactivity in varying degrees, as a result of the production of neutron-rich radioisotopes. Some atoms require more than one neu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ar-Ar Dating
Arar or Ar-Ar may refer to: Geography and history * Arar, Saudi Arabia, the capital of Al Hudud ash Shamaliyah (The Northern Border) province ** Arar border crossing, a Saudi-Iraqi border crossing near Arar, Saudi Arabia and Nukhayb, Iraq * Arar, Pakistan, a village in Sargodha District, Pakistan * Saône, a river in eastern France, formerly known as Arar * Battle of the Arar, a battle between the Romans and the Helvetii in 58 BC People * Ege Arar (born 1996), Turkish basketball player * Funda Arar (born 1975), Turkish singer * Maher Arar (born 1970), Canadian-Syrian engineer, deported from the US ** ''Arar v. Ashcroft'', a legal case brought by Maher Arar * Mustafa Wahbi al-Tal (1897–1949), Jordanian poet nicknamed Arar * Taleb Abu Arar (born 1967), Bedouin Israeli Arab politician Science * Argon–argon dating, a radiometric dating method * ''Juniperus phoenicea'', also known as Arâr, a juniper found throughout the Mediterranean region * '' Tetraclinis'', also known as arar, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fast Neutrons
The neutron detection temperature, also called the neutron energy, indicates a free neutron's kinetic energy, usually given in electron volts. The term ''temperature'' is used, since hot, thermal and cold neutrons are moderated in a medium with a certain temperature. The neutron energy distribution is then adapted to the Maxwell distribution known for thermal motion. Qualitatively, the higher the temperature, the higher the kinetic energy of the free neutrons. The momentum and wavelength of the neutron are related through the de Broglie relation. The large wavelength of slow neutrons allows for the large cross section. Neutron energy distribution ranges But different ranges with different names are observed in other sources. The following is a detailed classification: Thermal A thermal neutron is a free neutron with a kinetic energy of about 0.025 eV (about 4.0×10−21 J or 2.4 MJ/kg, hence a speed of 2.19 km/s), which is the energy corresponding to the most proba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epithermal Neutron
The neutron detection temperature, also called the neutron energy, indicates a free neutron's kinetic energy, usually given in electron volts. The term ''temperature'' is used, since hot, thermal and cold neutrons are moderated in a medium with a certain temperature. The neutron energy distribution is then adapted to the Maxwell distribution known for thermal motion. Qualitatively, the higher the temperature, the higher the kinetic energy of the free neutrons. The momentum and wavelength of the neutron are related through the de Broglie relation. The large wavelength of slow neutrons allows for the large cross section. Neutron energy distribution ranges But different ranges with different names are observed in other sources. The following is a detailed classification: Thermal A thermal neutron is a free neutron with a kinetic energy of about 0.025 eV (about 4.0×10−21 J or 2.4 MJ/kg, hence a speed of 2.19 km/s), which is the energy corresponding to the most pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cadmium
Cadmium is a chemical element with the symbol Cd and atomic number 48. This soft, silvery-white metal is chemically similar to the two other stable metals in group 12, zinc and mercury. Like zinc, it demonstrates oxidation state +2 in most of its compounds, and like mercury, it has a lower melting point than the transition metals in groups 3 through 11. Cadmium and its congeners in group 12 are often not considered transition metals, in that they do not have partly filled ''d'' or ''f'' electron shells in the elemental or common oxidation states. The average concentration of cadmium in Earth's crust is between 0.1 and 0.5 parts per million (ppm). It was discovered in 1817 simultaneously by Stromeyer and Hermann, both in Germany, as an impurity in zinc carbonate. Cadmium occurs as a minor component in most zinc ores and is a byproduct of zinc production. Cadmium was used for a long time as a corrosion-resistant plating on steel, and cadmium compounds are used as red, orang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fissile Material
In nuclear engineering, fissile material is material capable of sustaining a nuclear fission chain reaction. By definition, fissile material can sustain a chain reaction with neutrons of thermal energy. The predominant neutron energy may be typified by either slow neutrons (i.e., a thermal system) or fast neutrons. Fissile material can be used to fuel thermal-neutron reactors, fast-neutron reactors and nuclear explosives. Fissile vs fissionable According to the Ronen fissile rule, for a heavy element with 90 ≤ ''Z'' ≤ 100, its isotopes with , with few exceptions, are fissile (where ''N'' = number of neutrons and ''Z'' = number of protons).The fissile rule thus formulated indicates 33 isotopes as likely fissile: Th-225, 227, 229; Pa-228, 230, 232; U-231, 233, 235; Np-234, 236, 238; Pu-237, 239, 241; Am-240, 242, 244; Cm-243, 245, 247; Bk-246, 248, 250; Cf-249, 251, 253; Es-252, 254, 256; Fm-255, 257, 259. Only fourteen (including a long-lived ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
