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Random Positioning Machine
A random positioning machine, or RPM, rotates biological samples along two independent axes to change their orientation in space in complex ways and so eliminate the effect of gravity.Jack J.W.A. van Loon (2007). Some history and use of the random positioning machine, RPM, in gravity related research. Advances in Space Research 39: 1161-1165 Description The RPM is a more sophisticated development of the single-axis clinostat. RPMs usually consist of two independently rotating frames. One frame is positioned inside the other giving a very complex net change of orientation to a biological sample mounted in the middle. The RPM is sometimes wrongly referred to as the "3-D clinostat" (which rotates both axis in the same direction, i.e. both clockwise). It is a microweight ('micro-gravity') simulator that is based on the principle of 'gravity-vector-averaging'. RPM provides a functional volume which is 'exposed' to simulated microweight.A. G. Borst, J.J.W. A. van Loon. Technology and D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Clinostat
A clinostat is a device which uses rotation to negate the effects of gravitational pull on plant growth (gravitropism) and development ( gravimorphism). It has also been used to study the effects of microgravity on cell cultures, animal embryos and spider webs. Description A single axis (or horizontal) clinostat consists of a disc attached to a motor. They were originally clockwork but nowadays an electric motor is used. The disc is held vertically and the motor rotates it slowly at rates in the order of one revolution per minute. A plant is attached to the disc so that it is held horizontally. The slow rotation means that the plant experiences a gravitational pull that is averaged over 360 degrees, thus approximating a weightless environment. Clinostats have also been used to cancel out effects of sunlight and other stimuli besides gravity. This type of clinostat must be exactly horizontal to simulate absence of gravity. If the clinostat is at an angle from horizontal, a net gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Free Fall Machine
The free fall machine (FFM) is designed to permit the development of small biological sample such as cell cultures with a simulated effect of micro-gravity, under free fall conditions.Schwarzenberg M, Pippia P, Meloni MA, Cossu G, Cogoli-Greuter M, Cogoli A. (1999). Signal transduction in T lymphocytes--a comparison of the data from space, the free fall machine and the random positioning machine. Adv Space Res. 24(6): 793-800 Description The free fall machine (FFM) addresses some of the problems of the simple horizontal clinostat or random positioning machines (RPM). In a typical machine samples are allowed to cycle between free fall for about a metre down a column (micro-gravity simulation, near "0 g") and a "bounce" back to the top of the column that is intended to be so fast (c. 20 g for 20 ms) that it is undetected by the biological sample. Long duration of hyper-gravity is often simulated by machines such as the large diameter centrifuge (LDC) at ESA. To simulate partial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Gravity
In physics, gravity () is a fundamental interaction which causes mutual attraction between all things with mass or energy. Gravity is, by far, the weakest of the four fundamental interactions, approximately 1038 times weaker than the strong interaction, 1036 times weaker than the electromagnetic force and 1029 times weaker than the weak interaction. As a result, it has no significant influence at the level of subatomic particles. However, gravity is the most significant interaction between objects at the macroscopic scale, and it determines the motion of planets, stars, galaxies, and even light. On Earth, gravity gives weight to physical objects, and the Moon's gravity is responsible for sublunar tides in the oceans (the corresponding antipodal tide is caused by the inertia of the Earth and Moon orbiting one another). Gravity also has many important biological functions, helping to guide the growth of plants through the process of gravitropism and influencing th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Micro-g Environment
The term micro-g environment (also μg, often referred to by the term microgravity) is more or less synonymous with the terms ''weightlessness'' and ''zero-g'', but emphasising that g-forces are never exactly zero—just very small (on the International Space Station (ISS), for example, the small g-forces come from tidal effects, gravity from objects other than the Earth, such as astronauts, the spacecraft, and the Sun, air resistance, and astronaut movements that impart momentum to the space station). The symbol for microgravity, ''μg'', was used on the insignias of Space Shuttle flights STS-87 and STS-107, because these flights were devoted to microgravity research in low Earth orbit. The most commonly known microgravity environment can be found aboard the ISS which is located in low-earth orbit at an altitude of around 400 km, orbiting Earth approximately 15 times per day in what is considered free fall. The effects of free fall also enable the creation of short ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Hypergravity
Hypergravity is defined as the condition where the force of gravity exceeds that on the surface of the Earth. This is expressed as being greater than 1 '' g''. Hypergravity conditions are created on Earth for research on human physiology in aerial combat and space flight, as well as testing of materials and equipment for space missions. Manufacturing of titanium aluminide turbine blades in 20 ''g'' is being explored by researchers at the European Space Agency (ESA) via an 8-meter wide Large Diameter Centrifuge (LDC). Bacteria NASA scientists looking at meteorite impacts discovered that most strains of bacteria were able to reproduce under pressures exceeding 7,500 ''g''. Recent research carried out on extremophiles in Japan involved a variety of bacteria including ''Escherichia coli'' and ''Paracoccus denitrificans'' being subject to conditions of extreme gravity. The bacteria were cultivated while being rotated in an ultracentrifuge at high speeds corresponding t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Large Diameter Centrifuge
The large diameter centrifuge, or LDC, is any centrifuge extending several meters, which can rotate samples to change their acceleration in space to enhance the effect of gravity. Large diameter centrifuges are used to understand the effect of hyper-gravity (gravitational strengths stronger than that of the Earth) on biological samples, including and not limiting to plants, organs, bacteria, and astronauts (Such as NASA's Human Performance Centrifuge) or non-biological samples to undertake experiments in the field of fluid dynamics, geology, biochemistry and more. Description More often, the LDC is generally termed with the centrifuge situated within a dome structure at the European Space Agency (ESA)'s campus known as ESTEC. This centrifuge is an 8-m diameter four-arm centrifuge available for research. A total of six gondolas, each being able to carry a 80 kg payload, can spin at a maximum of 20 times the Earth's gravity, or a maximum of 67 revolutions per minute. Full ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Gravitropism
Gravitropism (also known as geotropism) is a coordinated process of differential growth by a plant in response to gravity pulling on it. It also occurs in fungi. Gravity can be either "artificial gravity" or natural gravity. It is a general feature of all higher and many lower plants as well as other organisms. Charles Darwin was one of the first to scientifically document that roots show ''positive gravitropism'' and stems show ''negative gravitropism''. That is, roots grow in the direction of gravitational pull (i.e., downward) and stems grow in the opposite direction (i.e., upwards). This behavior can be easily demonstrated with any potted plant. When laid onto its side, the growing parts of the stem begin to display negative gravitropism, growing (biologists say, turning; see tropism) upwards. Herbaceous (non-woody) stems are capable of a degree of actual bending, but most of the redirected movement occurs as a consequence of root or stem growth outside. The mechanism is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Laboratory Equipment
A laboratory (; ; colloquially lab) is a facility that provides controlled conditions in which scientific or technological research, experiments, and measurement may be performed. Laboratory services are provided in a variety of settings: physicians' offices, clinics, hospitals, and regional and national referral centers. Overview The organisation and contents of laboratories are determined by the differing requirements of the specialists working within. A physics laboratory might contain a particle accelerator or vacuum chamber, while a metallurgy laboratory could have apparatus for casting or refining metals or for testing their strength. A chemist or biologist might use a wet laboratory, while a psychologist's laboratory might be a room with one-way mirrors and hidden cameras in which to observe behavior. In some laboratories, such as those commonly used by computer scientists, computers (sometimes supercomputers) are used for either simulations or the analysis of da ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Gravitational Instruments
In physics, gravity () is a fundamental interaction which causes mutual attraction between all things with mass or energy. Gravity is, by far, the weakest of the four fundamental interactions, approximately 1038 times weaker than the strong interaction, 1036 times weaker than the electromagnetic force and 1029 times weaker than the weak interaction. As a result, it has no significant influence at the level of subatomic particles. However, gravity is the most significant interaction between objects at the macroscopic scale, and it determines the motion of planets, stars, galaxies, and even light. On Earth, gravity gives weight to physical objects, and the Moon's gravity is responsible for sublunar tides in the oceans (the corresponding antipodal tide is caused by the inertia of the Earth and Moon orbiting one another). Gravity also has many important biological functions, helping to guide the growth of plants through the process of gravitropism and influencing the ci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |