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Risø DTU National Laboratory For Sustainable Energy
Risø DTU National Laboratory for Sustainable Energy ( da, Risø DTU Nationallaboratoriet for Bæredygtig Energi) is a scientific research organization north of Roskilde, Denmark. The Risø DTU organisation was founded in 1956 and dissolved on 1 January 2012. The location is now known as DTU Risø Campus and the buildings are home to a number of institutes under the Technical University of Denmark (DTU) and separately is also home to Aarhus Universitybr>Dept of Environmental Scienceand part oDept of Bioscience Risø covers an area of more than 2.6 square kilometres. Organisation From 1 January 2008, it was made an institute of the Technical University of Denmark (DTU). On 1 January 2007, the Technical University of Denmark merged with the Danish Institute for Food and Veterinary Research, the Danish Institute for Fisheries Research, Danish National Space Center, the Danish Transport Research Institute and Risø National Laboratory. Before this, Risø National Laboratory was a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasma (physics)
Plasma () 1, where \nu_ is the electron gyrofrequency and \nu_ is the electron collision rate. It is often the case that the electrons are magnetized while the ions are not. Magnetized plasmas are ''anisotropic'', meaning that their properties in the direction parallel to the magnetic field are different from those perpendicular to it. While electric fields in plasmas are usually small due to the plasma high conductivity, the electric field associated with a plasma moving with velocity \mathbf in the magnetic field \mathbf is given by the usual Lorentz force, Lorentz formula \mathbf = -\mathbf\times\mathbf, and is not affected by Debye shielding. Mathematical descriptions To completely describe the state of a plasma, all of the particle locations and velocities that describe the electromagnetic field in the plasma region would need to be written down. However, it is generally not practical or necessary to keep track of all the particles in a plasma. Therefore, plasma physicist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eddy Covariance
The eddy covariance (also known as eddy correlation and eddy flux) is a key atmospheric measurement technique to measure and calculate vertical turbulent fluxes within atmospheric boundary layers. The method analyses high-frequency wind and scalar atmospheric data series, gas, energy, and momentum, which yields values of fluxes of these properties. It is a statistical method used in meteorology and other applications ( micrometeorology, oceanography, hydrology, agricultural sciences, industrial and regulatory applications, etc.) to determine exchange rates of trace gases over natural ecosystems and agricultural fields, and to quantify gas emissions rates from other land and water areas. It is frequently used to estimate momentum, heat, water vapour, carbon dioxide and methane fluxes.Burba, G., 2013. Eddy Covariance Method for Scientific, Industrial, Agricultural and Regulatory Applications: a Field Book on Measuring Ecosystem Gas Exchange and Areal Emission Rates. LI-COR Bioscience ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Climate Change
In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to Earth's climate. The current rise in global average temperature is more rapid than previous changes, and is primarily caused by humans burning fossil fuels. Fossil fuel use, deforestation, and some agricultural and industrial practices increase greenhouse gases, notably carbon dioxide and methane. Greenhouse gases absorb some of the heat that the Earth radiates after it warms from sunlight. Larger amounts of these gases trap more heat in Earth's lower atmosphere, causing global warming. Due to climate change, deserts are expanding, while heat waves and wildfires are becoming more common. Increased warming in the Arctic has contributed to melting permafrost, glacial retreat and sea ice loss. Higher temperatures are also causing m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solid-oxide Fuel Cells
A solid oxide fuel cell (or SOFC) is an electrochemical conversion device that produces electricity directly from oxidizing a fuel. Fuel cells are characterized by their electrolyte material; the SOFC has a solid oxide or ceramic electrolyte. Advantages of this class of fuel cells include high combined heat and power efficiency, long-term stability, fuel flexibility, low emissions, and relatively low cost. The largest disadvantage is the high operating temperature which results in longer start-up times and mechanical and chemical compatibility issues. Introduction Solid oxide fuel cells are a class of fuel cells characterized by the use of a solid oxide material as the electrolyte. SOFCs use a solid oxide electrolyte to conduct negative oxygen ions from the cathode to the anode. The electrochemical oxidation of the hydrogen, carbon monoxide or other organic intermediates by oxygen ions thus occurs on the anode side. More recently, proton-conducting SOFCs (PC-SOFC) are being deve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wind Energy
Wind power or wind energy is mostly the use of wind turbines to electricity generation, generate electricity. Wind power is a popular, sustainable energy, sustainable, renewable energy source that has a much smaller Environmental impact of wind power, impact on the environment than burning fossil fuels. Historically, wind power has been used in sails, windmills and windpumps but today it is mostly used to generate electricity. Wind farms consist of many individual wind turbines, which are connected to the electric power transmission Electrical grid, network. New Onshore wind farm, onshore (on-land) wind farms are cheaper than new Coal-fired power station, coal or Gas-fired power plant, gas plants, but expansion of wind power is being hindered by fossil fuel subsidies. Onshore wind farms have a greater visual #Impact on environment and landscape, impact on the landscape than some other power stations. Small onshore wind farms can feed some energy into the grid or provide power t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pool Reactor
NC State's PULSTAR Reactor is a 1 MW pool-type research reactor with 4% enriched, pin-type fuel consisting of UO2 pellets in right">The control room of North Carolina State University, NC State's Pulstar Nuclear Reactor. A swimming pool reactor, also called an open pool reactor, is a type of core (consisting of the fuel elements and the control rods) immersed in an open pool of usually water. The water acts as neutron moderator, cooling agent and radiation shield. The layer of water directly above the reactor core shields the radiation so completely that operators may work above the reactor safely. This design has two major advantages: the reactor is easily accessible and the whole primary cooling system, ''i.e.'' the pool water, is under normal pressure. This avoids the high temperatures and great pressures of nuclear power plants. Pool reactors are used as a source of neutrons and for training, and in rare instances for processing heat but not for electrical generation. Desc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homogenous Reactor
Homogeneity and heterogeneity are concepts often used in the sciences and statistics relating to the uniformity of a substance or organism. A material or image that is homogeneous is uniform in composition or character (i.e. color, shape, size, weight, height, distribution, texture, language, income, disease, temperature, radioactivity, architectural design, etc.); one that is heterogeneous is distinctly nonuniform in at least one of these qualities. Heterogeneous Mixtures, in chemistry, is where certain elements are unwillingly combined and, when given the option, will separate. Etymology and spelling The words ''homogeneous'' and ''heterogeneous'' come from Medieval Latin ''homogeneus'' and ''heterogeneus'', from Ancient Greek ὁμογενής (''homogenēs'') and ἑτερογενής (''heterogenēs''), from ὁμός (''homos'', “same”) and ἕτερος (''heteros'', “other, another, different”) respectively, followed by γένος (''genos'', “kind”); -ou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Reactor
A nuclear reactor is a device used to initiate and control a fission nuclear chain reaction or nuclear fusion reactions. Nuclear reactors are used at nuclear power plants for electricity generation and in nuclear marine propulsion. Heat from nuclear fission is passed to a working fluid (water or gas), which in turn runs through steam turbines. These either drive a ship's propellers or turn electrical generators' shafts. Nuclear generated steam in principle can be used for industrial process heat or for district heating. Some reactors are used to produce isotopes for medical and industrial use, or for production of weapons-grade plutonium. , the International Atomic Energy Agency reports there are 422 nuclear power reactors and 223 nuclear research reactors in operation around the world. In the early era of nuclear reactors (1940s), a reactor was known as a nuclear pile or atomic pile (so-called because the graphite moderator blocks of the first reactor were placed into a tall pi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DIDO (nuclear Reactor)
DIDO was a materials testing nuclear reactor at the Atomic Energy Research Establishment at Harwell, Oxfordshire in the United Kingdom. It used enriched uranium metal fuel, and heavy water as both neutron moderator and primary coolant. There was also a graphite neutron reflector surrounding the core. In the design phase, DIDO was known as AE334 after its engineering design number. DIDO was designed to have a high neutron flux, largely to reduce the time required for testing of materials intended for use in nuclear power reactors. This also allowed for the production of intense beams of neutrons for use in neutron diffraction. DIDO was shut down in 1990. The primary facilities decommissioning is expected to be complete in 2023 with the reactor decommissioning completed in 2031 and final site clearance achieved in 2064 In all, six DIDO class reactors were constructed based on this design: *DIDO, first criticality 1956. *PLUTO, also at Harwell, first criticality 1957. *HIFAR ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chairman
The chairperson, also chairman, chairwoman or chair, is the presiding officer of an organized group such as a board, committee, or deliberative assembly. The person holding the office, who is typically elected or appointed by members of the group, presides over meetings of the group, and conducts the group's business in an orderly fashion. In some organizations, the chairperson is also known as ''president'' (or other title). In others, where a board appoints a president (or other title), the two terms are used for distinct positions. Also, the chairman term may be used in a neutral manner not directly implying the gender of the holder. Terminology Terms for the office and its holder include ''chair'', ''chairperson'', ''chairman'', ''chairwoman'', ''convenor'', ''facilitator'', '' moderator'', ''president'', and ''presiding officer''. The chairperson of a parliamentary chamber is often called the ''speaker''. ''Chair'' has been used to refer to a seat or office of authority ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Niels Bohr
Niels Henrik David Bohr (; 7 October 1885 – 18 November 1962) was a Danish physicist who made foundational contributions to understanding atomic structure and quantum theory, for which he received the Nobel Prize in Physics in 1922. Bohr was also a philosopher and a promoter of scientific research. Bohr developed the Bohr model of the atom, in which he proposed that energy levels of electrons are discrete and that the electrons revolve in stable orbits around the atomic nucleus but can jump from one energy level (or orbit) to another. Although the Bohr model has been supplanted by other models, its underlying principles remain valid. He conceived the principle of complementarity: that items could be separately analysed in terms of contradictory properties, like behaving as a wave or a stream of particles. The notion of complementarity dominated Bohr's thinking in both science and philosophy. Bohr founded the Institute of Theoretical Physics at the University of Cope ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
