query: where do materials that decay or decompose come from

pos: Decomposition Decomposition Decomposition is the process by which organic substances are broken down into a more simple organic matter. The process is a part of the nutrient cycle and is essential for recycling the finite matter that occupies physical space in the biosphere. Bodies of living organisms begin to decompose shortly after death. Animals, such as worms, also help decompose the organic materials. Organisms that do this are known as decomposers. Although no two organisms decompose in the same way, they all undergo the same sequential stages of decomposition. The science which studies decomposition is generally referred to as "taphonomy" from

neg: Vermicompost in the bottom for excess liquid to drain into a tray for collection. The most common materials used are plastic: recycled polyethylene and polypropylene and wood. Worm compost bins made from plastic are ideal, but require more drainage than wooden ones because they are non-absorbent. However, wooden bins will eventually decay and need to be replaced. Small-scale vermicomposting is well-suited to turn kitchen waste into high-quality soil amendments, where space is limited. Worms can decompose organic matter without the additional human physical effort (turning the bin) that bin composting requires. Composting worms which are detritivorous (eaters of trash), such as

neg: Wood-decay fungus white-rot to inhabit. They can also decompose woods with high levels of compounds that are resistant to biological attack. Bark in woody plants contains a high concentration of tannin, which is difficult for fungi to decompose, and suberin which may act as a microbial barrier. The bark acts as form of protection for the more vulnerable interior of the plant. Soft-rot fungi do not tend to be able to decompose matter as effectively as white-rot fungi: they are less aggressive decomposers. White-rot fungi break down the lignin in wood, leaving the lighter-colored cellulose behind; some of them break down both

neg: Timeline of the far future second law of thermodynamics, which states that entropy, or a loss of the energy available to do work, must rise over time. Stars will eventually exhaust their supply of hydrogen fuel and burn out. Close encounters between astronomical objects gravitationally fling planets from their star systems, and star systems from galaxies. Physicists expect that matter itself will eventually come under the influence of radioactive decay, as even the most stable materials break apart into subatomic particles. Current data suggest that the universe has a flat geometry (or very close to flat), and thus will not collapse in on itself after

neg: Decomposition organic matter to soil microbes. The quality and quantity of the material available to decomposers is another major factor that influences the rate of decomposition. Substances like sugars and amino acids decompose readily and are considered labile. Cellulose and hemicellulose, which are broken down more slowly, are "moderately labile". Compounds which are more resistant to decay, like lignin or cutin, are considered recalcitrant. Litter with a higher proportion of labile compounds decomposes much more rapidly than does litter with a higher proportion of recalcitrant material. Consequently, dead animals decompose more rapidly than dead leaves, which themselves decompose more rapidly than

neg: Humus bacteria, microbes and animals such as earthworms, nematodes, protozoa, and arthropods. Plant remains, including those that animals digested and excreted, contain organic compounds: sugars, starches, proteins, carbohydrates, lignins, waxes, resins, and organic acids. Decay in the soil begins with the decomposition of sugars and starches from carbohydrates, which decompose easily as detritivores initially invade the dead plant organs, while the remaining cellulose and lignin decompose more slowly. Simple proteins, organic acids, starches, and sugars decompose rapidly, while crude proteins, fats, waxes, and resins remain relatively unchanged for longer periods of time. Lignin, which is quickly transformed by white-rot fungi, is

neg: Herbicide seed contributed to the consolidation of the seed and chemistry industry in the late 1990s. Many modern chemical herbicides used in agriculture and gardening are specifically formulated to decompose within a short period after application. This is desirable, as it allows crops and plants to be planted afterwards, which could otherwise be affected by the herbicide. However, herbicides with low residual activity (i.e., that decompose quickly) often do not provide season-long weed control and do not ensure that weed roots are killed beneath construction and paving (and cannot emerge destructively in years to come), therefore there remains a role for

neg: Leather wastes representing up to 70% of the wet weight of the original hides, the tanning process represents a considerable strain on water treatment installations. Leather biodegrades slowly—taking 25 to 40 years to decompose. However, vinyl and petrochemical-derived materials take 500 or more years to decompose. Tanning is especially polluting in countries where environmental regulations are lax, such as in India, the world's third-largest producer and exporter of leather. To give an example of an efficient pollution prevention system, chromium loads per produced tonne are generally abated from 8 kg to 1.5 kg. VOC emissions are typically reduced from 30 kg/t

neg: Age of the Earth rate is given in terms of a "half-life", or the amount of time it takes half of a mass of that radioactive material to break down into its "decay product". Some radioactive materials have short half-lives; some have long half-lives. Uranium and thorium have long half-lives, and so persist in Earth's crust, but radioactive elements with short half-lives have generally disappeared. This suggested that it might be possible to measure the age of Earth by determining the relative proportions of radioactive materials in geological samples. In reality, radioactive elements do not always decay into nonradioactive ("stable") elements directly, instead, decaying

neg: Phosphor Phosphor A phosphor, most generally, is a substance that exhibits the phenomenon of luminescence. Somewhat confusingly, this includes both phosphorescent materials, which show a slow decay in brightness (> 1 ms), and fluorescent materials, where the emission decay takes place over tens of nanoseconds. Phosphorescent materials are known for their use in radar screens and glow-in-the-dark materials, whereas fluorescent materials are common in cathode ray tube (CRT) and plasma video display screens, fluorescent lights, sensors, and white LEDs. Phosphors are often transition-metal compounds or rare-earth compounds of various types. The most common uses of phosphors are in CRT displays and

neg: Guaibasaurus the neck, and MCN PV 10112 is still being unprepared block containing articulated parts and some isolated elements of which, including a partial hand. The referred materials were collected from the "Linha São Luiz" locality near the town of Faxinal do Soturno, Rio Grande do Sul, also in the geopark of Paleorrota. All specimen were collected in these two localities from the lower portion of the Caturrita Formation (Rosário do Sul Group, Paraná Basin) or alternatively the uppermost Santa Maria 2 Sequence, dating to the early Norian faunal stage of the Late Triassic. A U-Pb (Uranium decay) dating found that

neg: Alternative fuel a problem. Radiothermal generators (RTGs) which use such radioisotopes as fuels do not sustain a nuclear chain reaction, but rather generate electricity from the decay of a radioisotope which has (in turn) been produced on Earth as a concentrated power source (fuel) using energy from an Earth-based nuclear reactor. Alternative fuel Alternative fuels, known as non-conventional and advanced fuels, are any materials or substances that can be used as fuels, other than conventional fuels like; "fossil fuels" (petroleum (oil), coal, and natural gas), as well as nuclear materials such as uranium and thorium, as well as artificial radioisotope fuels that

neg: Neon-burning process Neon-burning process The neon-burning process (nuclear decay) is a set of nuclear fusion reactions that take place in massive stars (at least 8 Solar masses). Neon burning requires high temperatures and densities (around 1.2×10 K or 100 KeV and 4×10 kg/m). At such high temperatures photodisintegration becomes a significant effect, so some neon nuclei decompose, releasing alpha particles: Alternatively: where the neutron consumed in the first step is regenerated in the second. Neon burning takes place after carbon burning has consumed all carbon in the core and built up a new oxygen-neon-sodium-magnesium core. The core ceases producing fusion energy and

neg: Carbide scandium, yttrium, and lanthanum. Aluminium from group 13 forms carbides, but gallium, indium, and thallium do not. These materials feature isolated carbon centers, often described as "C", in the methanides or methides; two-atom units, "", in the acetylides; and three-atom units, "", in the sesquicarbides. The graphite intercalation compound KC, prepared from vapour of potassium and graphite, and the alkali metal derivatives of C are not usually classified as carbides. Carbides of this class decompose in water producing methane. Three such examples are aluminium carbide , magnesium carbide and beryllium carbide . Transition metal carbides are not saline carbides but

neg: Bias–variance tradeoff be minimal, both for formula_1 "and for points outside of our sample". Of course, we cannot hope to do so perfectly, since the formula_2 contain noise formula_5; this means we must be prepared to accept an "irreducible error" in any function we come up with. Finding an formula_15 that generalizes to points outside of the training set can be done with any of the countless algorithms used for supervised learning. It turns out that whichever function formula_15 we select, we can decompose its expected error on an unseen sample formula_17 as follows: where and The expectation ranges over different choices

neg: Decay heat Decay heat Decay heat is the heat released as a result of radioactive decay. This heat is produced as an effect of radiation on materials: the energy of the alpha, beta or gamma radiation is converted into the thermal movement of atoms. Decay heat occurs naturally from decay of long-lived radioisotopes that are primordially present from the Earth's formation. In nuclear reactor engineering, decay heat continues to be generated after the reactor has been shut down (see SCRAM), and nuclear chain reactions have been suspended. The decay of the short-lived radioisotopes created in fission continues at high power, for a

neg: Boston Harbor area which has a history of shipbuilding including the notable Fore River Shipyard. In the 1830s members of the maritime community observed physical decay in the harbor. Islands in the outer harbor were visibly deteriorating and erosion was causing weathered materials and sediment to move from where it was protecting the harbor to where it would do the most harm. Recent shoaling experiences and comparisons with old charts caused observers to insist that the inner harbor was also filling and created widespread anxiety about the destruction of the Boston Harbor. Although the scientific understanding of hydraulics was still in its

neg: Non-stop decay Non-stop decay Non-stop decay is a cellular mechanism of mRNA surveillance to detect mRNA molecules lacking a stop codon and prevent these mRNAs from translation. The non-stop decay pathway releases ribosomes that have reached the far 3' end of an mRNA and guides the mRNA to the exosome complex, or to RNase R in bacteria for selective degradation. In contrast to NMD, polypeptides do not release from the ribosome, and thus, NSD seems to involve mRNA decay factors distinct from NMD. Non-stop decay is a cellular pathway that identifies and degrades aberrant mRNA transcripts that do not contain a proper

neg: Bog body than the 2,500 years that Haraldskær Woman's body has survived. Most of the bog bodies discovered showed some aspects of decay or else were not properly conserved. When such specimens are exposed to the normal atmosphere, they may begin to decompose rapidly. As a result, many specimens have been effectively destroyed. As of 1979, the number of specimens that have been preserved following discovery was 53. The oldest bog body that has been identified is the Koelbjerg Man from Denmark, who has been dated to 8000 BCE, during the Mesolithic period. Around 3900 BCE, agriculture was introduced to Denmark, either

neg: Chinese alchemical elixir poisoning an elixir-taker's corpse is Needham and Lu's second explanation for the persistent belief in immortality elixirs. They suggest that in some cases a body did not decompose because the deceased had died from mercury or arsenic poisoning, which is forensically known to often preserve a corpse from decay. For a believer in Daoist immortality drugs, even when an elixir-taker had unmistakably died, if the corpse was comparatively undecomposed, that could be interpreted as proof that the adept had become a "xian" immortal, as well as evidence for the alchemical elixir's efficacy. (1974: 298). Terminal incorruptibility was an ancient Chinese belief

neg: Cradle-to-cradle design to non-toxic, non-harmful synthetic materials that have no negative effects on the natural environment; they can be used in continuous cycles as the same product without losing their integrity or quality. In this manner these materials can be used over and over again instead of being "downcycled" into lesser products, ultimately becoming waste. "Biological Nutrients" are organic materials that, once used, can be disposed of in any natural environment and decompose into the soil, providing food for small life forms without affecting the natural environment. This is dependent on the ecology of the region; for example, organic material from one

neg: Plastic shopping bag degradable bags do not readily decompose in a sealed landfill, and represent a possible contaminant to plastic recycling operations. In general, biodegradable plastic bags need to be kept separate from conventional plastic recycling systems. Biodegradable plastics are plastics that are decomposed by the action of living organisms, usually bacteria. Two basic classes of biodegradable plastics exist: Bioplastics, whose components are derived from renewable raw materials, and plastics made from petrochemicals containing biodegradable additives which enhance biodegradation. Because plastic bags are so durable, this makes them a concern for the environment. They will not break down easily and as a result

neg: Burial at sea parishes have specific consecrated sea areas where ashes can be sprinkled. Traditionally, the deceased are cremated, the bones and ashes are collected, and the ashes/remains are immersed in the Ganges River if possible or in any other river if not. The sacred texts of Islam prefer burial on land, "so deep that its smell does not come out and the beasts of prey do not dig it out". However, if a person dies at sea and it is not possible to bring the body back to land before decay, or if burial at land becomes impossible, burial at sea is

neg: Russell Mills (artist) the Spiral", the 1997 videocassette compilation "Closure", the 2004 Deluxe Edition and DualDisc re-releases of "The Downward Spiral", (which was accompanied by several new Mills compositions downloadable from the nine Inch Nails website), and various promotional materials. These interrelated works contain Mills' heaviest use of organic materials to depict a sense of fragility and decay. Animal skeletons, sets of teeth, blood, feathers, and dead insects are liberally embedded in the canvases. In some pieces, materials have been affixed and then exposed to water or chemical elements, so that their decay is literally imprinted on the surface of the artwork. In

neg: Urine-diverting dry toilet after defecation—or for wiping after urination—UDDT users can avail themselves of the same materials that are utilized while using other types of toilets. Suitable biodegradable materials available in the surroundings can also be used, such as toilet paper, leaves, corn cobs or sticks. These materials are deposited along with feces in the feces portion of the toilet so that everything can eventually decompose together. For example, in Ecuador the soft, perfumed leaves of "Piper auritum", "Piperaceae" and "Melastomataceae" are being used. Users have also used stones, although this makes the vault fill up very fast and is therefore not practical

neg: Phosphor degradation-prone, and the plate-like morphology of its crystals hampers its use; these problems are solved now, so it is gaining use due to its higher linearity. YOS:Eu is used for red emission. Some other phosphors commercially available, for use as X-ray screens, neutron detectors, alpha particle scintillators, etc., are: Phosphor A phosphor, most generally, is a substance that exhibits the phenomenon of luminescence. Somewhat confusingly, this includes both phosphorescent materials, which show a slow decay in brightness (> 1 ms), and fluorescent materials, where the emission decay takes place over tens of nanoseconds. Phosphorescent materials are known for their use

neg: Neutron reaction sources (that involve two materials) powered by radioisotopes use an alpha decay source plus a beryllium target, or else a source of high-energy gamma radiation from a source that undergoes beta decay followed by gamma decay, which produces photoneutrons on interaction of the high-energy gamma ray with ordinary stable beryllium, or else with the deuterium in heavy water. A popular source of the latter type is radioactive antimony-124 plus beryllium, a system with a half-life of 60.9 days, which can be constructed from natural antimony (which is 42.8% stable antimony-123) by activating it with neutrons in a nuclear reactor,

neg: Volatile corrosion inhibitor of VCI. VCI materials will not protect all metals from corrosion; in fact, they appear to increase the rate of corrosion in certain metals. VCI materials must not be used to protect any assemblies containing optical systems or precision moving parts which have been coated with a preservative or lubricant, unless otherwise specified. Items protected with bonded films, such as molybdenum (a dry lubricant), are not included in this category . VCI materials are affected by heat and light. They lose their effectiveness as the temperature increases and they decompose if exposed to direct sunlight for extended periods. They also

neg: Ronald Wilfred Gurney Ronald Wilfred Gurney Ronald Wilfred (or Wilfrid) Gurney (1898, Cheltenham, England – 14 April 1953, New York, New York) was a British theoretical physicist and research pupil of William Lawrence Bragg at the Victoria University of Manchester during the 1920s and 1930s, Bristol University during the 1930s and later in the USA, where he died. Whilst at the Palmer Physical Laboratory at Princeton University from 1926–28, he discovered alpha decay via quantum tunnelling, together with Edward Condon and independently of George Gamow. In the early 1900s, radioactive materials were known to have characteristic exponential decay rates or half lives. At

neg: Mudrock mudstone into a metamorphosed gneiss. The metamorphosed gneiss will make its way to the surface once again as country rock or as magma in a volcano, and the whole process will begin again. Mudrocks form in various colors, including: red, purple, brown, yellow, green and grey, and even black. Shades of grey are most common in mudrocks, and darker colors of black come from organic carbons. Green mudrocks form in reducing conditions, where organic matter decomposes along with ferric iron. They can also be found in marine environments, where pelagic, or free-floating species, settle out of the water and decompose

neg: Gamma ray excited state. It can then decay to a lower energy state by emitting a gamma ray photon, in a process called gamma decay. The emission of a gamma ray from an excited nucleus typically requires only 10 seconds. Gamma decay may also follow nuclear reactions such as neutron capture, nuclear fission, or nuclear fusion. Gamma decay is also a mode of relaxation of many excited states of atomic nuclei following other types of radioactive decay, such as beta decay, so long as these states possess the necessary component of nuclear spin. When high-energy gamma rays, electrons, or protons bombard materials,

neg: Paul of Taranto contains the substantial form of the wood, so clearly that form must have been there even when the tree was alive. Paul’s experimental approach is to decompose metals into other materials, then attempt to recombine those materials into the metal again. If the sulfur-mercury theory is correct, you can decompose metals into the four elements, but when attempting to recombine the elements, there is no reason for the elements to recombine into any one particular metal. Paul writes that he successfully recreated the same metal after a process of calcining, dissolving, subliming, and lastly reducing metals. Since he was able

neg: Dealkalization "bloom", on the glass surface that must be rinsed away prior to filling. On manufacturing lines, one way in which this process was done was by flooding the annealing lehr with sulfur dioxide (SO) or sulfur trioxide (SO) gases—especially in the presence of water, which enhances the reaction. However, this practice fell into disfavor due to environmental and health concerns regarding SO-type gases. An alternative method for sulfate treatment is with solid ammonium sulfate salt or aqueous solutions thereof. These materials are introduced inside the container after forming and decompose into gases in the annealing lehr, where the resulting sulfur-containing

neg: Myxotrichum chartarum the Latin word for paper and is in reference to its initial discovery from paper in books, and its ability to decay these materials through the production of cellulose-degrading enzymes (cellulases). It was deemed a “material pathogen”, since it is able to degrade specific materials for a source of nutrition. It has also been recorded to inhabit other materials such as, drywall, straw, decaying leather, cloth, grouse dung, rabbit dung, bat guano, soil, leaves and fruit. Reports of "M. chartarum" have come from around the world. Known distribution areas are as follows: Germany, Russia, Italy, France, Switzerland, England, Japan, Austria-Hungary,

neg: Zoothamnium mature into macrozooids, and will detach from the stalk and swim away. Colonies may become large, as the macrozooids may not have to travel far to find additional substrate. The initial colony will eventually enter into a senescent phase, where it will slow or even stop its biological functions of replication and release of swarmer cells. At this point microzooids will begin to die from the bottom of the stalk progressing to the top. A variety of bacteria will establish on the remaining stalk and decompose the materials. Zoothamnium Zoothamnium is a genus of ciliate protozoan. "Zoothamnium" was initially classified

neg: Wood-decay fungus lignicolous fungi consume wood in various ways; for example, some attack the carbohydrates in wood and some others decay lignin. The rate of decay of wooden materials in various climates can be estimated by empirical models. Wood-decay fungi can be classified according to the type of decay that they cause. The best-known types are brown rot, soft rot, and white rot. Each produce different enzymes, can degrade different plant materials, and can colonise different environmental niches. The residual products of decomposition from fungal action have variable pH, solubility and redox potentials. Over time this residue will become incorporated in the

neg: Wind chime little to do with the pitch being produced. Sound can be produced when the tubes or rods come in contact with a suspended central clapper in the form of a ball or horizontal disk, or with each other. Wind chimes may be used to observe changes in wind direction, depending on where they are hung when they commence to sound. Wind chimes can be made of materials other than metal or wood and in shapes other than tubes or rods. Other wind chimes materials include glass, bamboo, shell, stone, earthenware, stoneware, beads, keys and porcelain. More exotic items, such as

neg: O-ring O-ring materials may be subjected to high or low temperatures, chemical attack, vibration, abrasion, and movement. Elastomers are selected according to the situation. There are O-ring materials which can tolerate temperatures as low as -200 C or as high as 250+ C. At the low end, nearly all engineering materials become rigid and fail to seal; at the high end, the materials often burn or decompose. Chemical attack can degrade the material, start brittle cracks or cause it to swell. For example, NBR seals can crack when exposed to ozone gas at very low concentrations, unless protected. Swelling by contact

neg: Strontianite in X-rays and electron beams. All materials will glow red hot if they are heated to a high enough temperature (provided they do not decompose first); some materials become luminescent at much lower temperatures, and this is known as thermoluminescence. Strontianite is sometimes thermoluminescent. Cleavage is nearly perfect parallel to one set of prism faces, {110}, and poor on {021}. Traces of cleavage have been observed on {010}. Twinning is very common, with twin plane {110}. The twins are usually contact twins; in a contact twin the two individuals appear to be reflections of each other in the twin plane.

neg: Forensic entomological decomposition factors that may speed up decomposition. Corpses with open wounds, whether pre or post mortem, tend to decompose faster due to easier insect access. The cause of death likewise can leave openings in the body that allow insects and bacteria access to the inside body cavities in earlier stages of decay. Flies oviposit eggs inside natural openings and wounds that may become exaggerated when the eggs hatch and the larvae begin feeding. Wraps, garments, and clothing have shown to affect the rate of decomposition because the corpse is covered by some type of barrier. Wraps, such as tight fighting tarps

neg: Urðarbrunnr (Urðarbrunnr), and from this hall come "three maidens" whose names are Urðr, Verðandi, and Skuld. The maidens shape the lives of men, and "we call them norns". High goes on to describe that there are other norns, and their nature. Further into chapter 16, High states that norns that dwell by Urðarbrunnr take water from the well and mud that lies around it, and pour it over the Yggdrasil so that its branches do not decay or rot. The water is described as so holy that anything that enters the well will become "as white as the membrane called the

neg: Microbiology of decomposition part of anaerobic putrefactive bacteria. <br> Cadavers and carcasses are usually left to decompose in contact with soil whether through burial in a grave or if left to decompose on the soil surface. This allows microorganisms in the soil and air to come in contact with the body and to take part in the decomposition process. Soil microorganism communities also undergo changes as a result of decomposition fluids leaching in the environment. Cadavers and carcasses often show signs of fungal growth suggesting that fungi use the body as a source of nutrients. The exact impacts that decomposition may have on

neg: Spontaneous emission radiative transitions. For many materials (for instance, semiconductors), electrons move quickly from a high energy level to a meta-stable level via small nonradiative transitions and then make the final move down to the bottom level via an optical or radiative transition. This final transition is the transition over the bandgap in semiconductors. Large nonradiative transitions do not occur frequently because the crystal structure generally cannot support large vibrations without destroying bonds (which generally doesn't happen for relaxation). Meta-stable states form a very important feature that is exploited in the construction of lasers. Specifically, since electrons decay slowly from them, they

neg: Indoor air quality as regards second-hand smoke is the implementation of comprehensive smoke-free laws. Radon is an invisible, radioactive atomic gas that results from the radioactive decay of radium, which may be found in rock formations beneath buildings or in certain building materials themselves. Radon is probably the most pervasive serious hazard for indoor air in the United States and Europe, probably responsible for tens of thousands of deaths from lung cancer each year. There are relatively simple test kits for do-it-yourself radon gas testing, but if a home is for sale the testing must be done by a licensed person in some

neg: Love wave layers of particles. The amplitude, or maximum particle motion, often decreases rapidly with depth. Since Love waves travel on the Earth's surface, the strength (or amplitude) of the waves decrease exponentially with the depth of an earthquake. However, given their confinement to the surface, their amplitude decays only as formula_1, where formula_2 represents the distance the wave has travelled from the earthquake. Surface waves therefore decay more slowly with distance than do body waves, which travel in three dimensions. Large earthquakes may generate Love waves that travel around the Earth several times before dissipating. Since they decay so slowly, Love

neg: Wood exists as to whether the wood dies during heartwood formation, as it can still chemically react to decay organisms, but only once. Heartwood is often visually distinct from the living sapwood, and can be distinguished in a cross-section where the boundary will tend to follow the growth rings. For example, it is sometimes much darker. However, other processes such as decay or insect invasion can also discolor wood, even in woody plants that do not form heartwood, which may lead to confusion. Sapwood (or alburnum) is the younger, outermost wood; in the growing tree it is living wood, and its

neg: Fairphone 2 Some manufacturers therefore avoid all materials from the DRC, but this reduces employment opportunities in the country. The Fairphone 2 supply chain is audited to ensure that these materials come from mines that do not fund armed groups, while supporting local communities in the DRC (where possible) in order to provide an alternative to conflict mines. The tantalum and tin ores are sourced from conflict-free mines in the DRC, the tungsten is from Rwanda, and the gold is from a Fairtrade-certified mine in Peru. In addition, the phone includes recycled plastic, copper, and tungsten. The Fairphone 2 is assembled by

neg: Geoneutrino amount of heat in the earth's mantle, and these are presently the main contributors to radiogenic heat. However, neutrino flux does not perfectly track heat from radioactive decay of primordial nuclides, because neutrinos do not carry off a constant fraction of the energy from the radiogenic decay chains of these primordial radionuclides. Instruments that measure geoneutrinos are large scintillation detectors. They use the inverse beta decay reaction, a method proposed by Bruno Pontecorvo that Frederick Reines and Clyde Cowan employed in their pioneering experiments in 1950s. Inverse beta decay is a charged current weak interaction, where an electron antineutrino interacts

neg: Gamma ray not from radioactive decay or particle annihilation, but rather in non-radioactive processes similar to X-rays. Although the gamma rays of astronomy often come from non-radioactive events, a few gamma rays in astronomy are specifically known to originate from gamma decay of nuclei (as demonstrated by their spectra and emission half life). A classic example is that of supernova SN 1987A, which emits an "afterglow" of gamma-ray photons from the decay of newly made radioactive nickel-56 and cobalt-56. Most gamma rays in astronomy, however, arise by other mechanisms. Gamma ray A gamma ray or gamma radiation (symbol γ or formula_1), is

neg: Longbow yew, or from wych elm if yew was unavailable. The historical longbow was a self bow made of a single piece of wood, but modern longbows may also be made from modern materials or by gluing different timbers together. Organisations that run archery competitions have set out formal definitions for the various classes; many definitions of the longbow would exclude some medieval examples, materials, and techniques of use. Some archery clubs in the USA classify longbows simply as bows with strings that do not come in contact with their limbs. According to the British Longbow Society, the English longbow is

neg: Thermoset polymer matrix (~ 300 °C) converts all silicone polymers into ceramics since all organic constituents pyrolytically decompose leaving crystalline silicate polymers with the general formula (-SiO2-)n. In addition to applications as ceramic matrix composite precursors, silicone resins in the form of polysiloxane polymers made from silicone resins with pendant acrylate, vinyl ether or epoxy functionality find application as UV, electron beam and thermoset polymer matrix composites where they are characterised by their resistance to oxidation, heat and ultraviolet degradation. Assorted other uses in the general area of composites for silicones include sealants, coating materials, and as a reusable bag material for vacuum-bag

neg: Decay heat dissipated into the air by recirculating the water via a cooling tower. The failure of ESWS circulating pumps was one of the factors that endangered safety during the 1999 Blayais Nuclear Power Plant flood. After one year, typical spent nuclear fuel generates about 10 kW of decay heat per tonne, decreasing to about 1 kW/t after ten years. Hence effective active or passive cooling for spent nuclear fuel is required for a number of years. Decay heat Decay heat is the heat released as a result of radioactive decay. This heat is produced as an effect of radiation on materials:

neg: Resource recovery excreta or organic waste can produce fly larvae as a protein feed. Other researchers are harvesting fatty acids from wastewater to make bioplastics. Disposed materials that are organic in nature, such as plant material, food scraps, and paper products, can be recycled using biological composting and digestion processes to decompose the organic matter. The resulting organic material is then recycled as mulch or compost for agricultural or landscaping purposes. In addition, waste gas from the process (such as methane) can be captured and used for generating electricity and heat (CHP/cogeneration) maximising efficiencies. The intention of biological processing is to control

neg: Spinor or it may decompose into a pair of so-called "half-spin" or Weyl representations. The space of spinors is formally defined as the fundamental representation of the Clifford algebra. (This may or may not decompose into irreducible representations.) The space of spinors may also be defined as a spin representation of the orthogonal Lie algebra. These spin representations are also characterized as the finite-dimensional projective representations of the special orthogonal group that do not factor through linear representations. Equivalently, a spinor is an element of a finite-dimensional group representation of the spin group on which the center acts non-trivially. There are

neg: Fanny Gates Fanny Gates Fanny Cook Gates (26 April 1872 – 24 February 1931) was an American physicist, an American Physical Society fellow and American Mathematical Society member. She made contributions to the research of radioactive materials, determining that radioactivity could not be destroyed by heat or ionization due to chemical reactions, and that radioactive materials differ from phosphorescent materials both qualitatively and quantitatively. More specifically, Gates showed that the emission of blue light from quinine was temperature dependent, providing evidence that the emitted light is produced from phosphorescence rather than radioactive decay. She also served as head of the Physics department

neg: Waste management city and country has different recycling programs in place that can handle the various types of recyclable materials. However, certain variation in acceptance is reflected in the resale value of the material once it is reprocessed. In July 2017, the Chinese government announced an import ban of 24 categories of recyclables and solid waste, including plastic, textiles and mixed paper, placing tremendous impact on developed countries globally, which exported directly or indirectly to China. Recoverable materials that are organic in nature, such as plant material, food scraps, and paper products, can be recovered through composting and digestion processes to decompose

neg: Atom majority of atoms combine to form various compounds, including water, salt, silicates and oxides. Atoms can also combine to create materials that do not consist of discrete molecules, including crystals and liquid or solid metals. This atomic matter forms networked arrangements that lack the particular type of small-scale interrupted order associated with molecular matter. While isotopes with atomic numbers higher than lead (82) are known to be radioactive, an "island of stability" has been proposed for some elements with atomic numbers above 103. These superheavy elements may have a nucleus that is relatively stable against radioactive decay. The most likely

neg: Isobar (nuclide) decay is favorable for strongly neutron-deficient nuclides. Both decay modes do not change the mass number, hence an original nucleus and its daughter nucleus are isobars. In both aforementioned cases, a heavier nucleus decays to its lighter isobar. For even the term has the form: where is another constant. This term, subtracted from the mass expression above, is positive for even-even nuclei and negative for odd-odd nuclei. This means that even-even nuclei, which have not a strong neutron excess or neutron deficiency, have higher binding energy than their odd-odd isobar neighbors. It implies that even-even nuclei are (relatively) lighter and

neg: Decay chain lead-207. The total energy released from uranium-235 to lead-207, including the energy lost to neutrinos, is 46.4 MeV. Decay chain In nuclear science, the decay chain refers to a series of radioactive decays of different radioactive decay products as a sequential series of transformations. It is also known as a "radioactive cascade". Most radioisotopes do not decay directly to a stable state, but rather undergo a series of decays until eventually a stable isotope is reached. Decay stages are referred to by their relationship to previous or subsequent stages. A "parent isotope" is one that undergoes decay to form a

neg: Internal conversion Internal conversion Internal conversion is a radioactive decay process wherein an excited nucleus interacts electromagnetically with one of the orbital electrons of the atom. This causes the electron to be emitted (ejected) from the atom. Thus, in an internal conversion process, a high-energy electron is emitted from the radioactive atom, but not from the nucleus. For this reason, the high-speed electrons resulting from internal conversion are not called beta particles, since the latter come from beta decay, where they are newly created in the nuclear decay process. Internal conversion is possible whenever gamma decay is possible, except in the case

neg: Conservation and restoration of film These promote silver corrosion and decompose the gelatin emulsion layer. The chemical reactions that occur cause further nitrate decay. Softness and stickiness occur and the image starts to fade away. This is irreversible. When exposed to moisture in the environment and various pollutants, the image silver will corrode, creating a reflective metallic sheen on the emulsion side. Typically starts at the edges of the film. Poor quality enclosures and storage can hasten the process. These small pink, orange or yellow spots can found in the image area and are often found in microfilm. These are created by local oxidation of

neg: Zooarchaeology a valuable part in contributing to a holistic understanding of the animals themselves, the nearby groups, and the local environments. Zooarchaeology Zooarchaeology (or archaeozoology) is the branch of archaeology that studies faunal remains related to ancient people. Faunal remains are the items left behind when an animal dies. It includes: bones, shells, hair, chitin, scales, hides, proteins and DNA. Of these items, bones and shells are the ones that occur most frequently at archaeological sites where faunal remains can be found. Most of the time, most of the faunal remains do not survive. They often decompose or break because of

neg: Zooarchaeology Zooarchaeology Zooarchaeology (or archaeozoology) is the branch of archaeology that studies faunal remains related to ancient people. Faunal remains are the items left behind when an animal dies. It includes: bones, shells, hair, chitin, scales, hides, proteins and DNA. Of these items, bones and shells are the ones that occur most frequently at archaeological sites where faunal remains can be found. Most of the time, most of the faunal remains do not survive. They often decompose or break because of various circumstances. This can cause difficulties in identifying the remains and interpreting their significance. The development of zooarchaeology in Eastern

neg: Decomposer they must ingest nutrients and are unable to absorb them externally. The primary decomposer of litter in many ecosystems are fungi. Unlike bacteria, which are unicellular organisms, most saprotrophic fungi grow as a branching network of hyphae. While bacteria are restricted to growing and feeding on the exposed surfaces of organic matter, fungi can use their hyphae to penetrate larger pieces of organic matter. Additionally, only wood-decay fungi have evolved the enzymes necessary to decompose lignin, a chemically complex substance found in wood. These two factors make fungi the primary decomposers in forests, where litter has high concentrations of lignin

neg: Rayleigh wave elastic constants of the material. The typical speed of Rayleigh waves in metals is of the order of 2–5 km/s, and the typical Rayleigh speed in the ground is of the order of 50–300 m/s. For linear elastic materials with positive Poisson ratio (formula_1), the Rayleigh wave speed can be approximated as formula_2. Since Rayleigh waves are confined near the surface, their in-plane amplitude when generated by a point source decays only as formula_3, where formula_4 is the radial distance. Surface waves therefore decay more slowly with distance than do bulk waves, which spread out in three dimensions from a

neg: Relative biological effectiveness can do significant damage only if they come from the decay of atoms inside the body. Since the range of an alpha particle is typically about the diameter of a single eukaryotic cell, the precise location of the emitting atom in the tissue cells becomes significant. For this reason, it has been suggested that the health impact of contamination by alpha emitters might have been substantially underestimated. Measurements of RBE with external sources also neglect the ionization caused by the recoil of the parent-nucleus due to the alpha decay. While the recoil of the parent-nucleus of the decaying atom typically

neg: Chemical vapor deposition Chemical vapor deposition Chemical vapor deposition (CVD) is a deposition method used to produce high quality, high-performance, solid materials, typically under vacuum. The process is often used in the semiconductor industry to produce thin films. In typical CVD, the wafer (substrate) is exposed to one or more volatile precursors, which react and/or decompose on the substrate surface to produce the desired deposit. Frequently, volatile by-products are also produced, which are removed by gas flow through the reaction chamber. Microfabrication processes widely use CVD to deposit materials in various forms, including: monocrystalline, polycrystalline, amorphous, and epitaxial. These materials include: silicon (dioxide,

neg: Airbag as the lowest initial temperature of reaction. The N and CO gases evolved made up 99% of all gases evolved. Nearly all the starting materials won’t decompose until reaching temperatures of 500 °C or higher so this could be a viable option as an air bag gas generator. In a patent containing another plausible alternative to NaN driven airbags, the gas generating materials involved the use of guanidine nitrate, 5-aminotetrazole, bitetrazole dihydrate, nitroimidazole, and basic copper nitrate. It was found that these non-azide reagents allowed for a less toxic, lower combustion temperature reaction and more easily disposable air bag inflation

neg: Behula that snakes could not penetrate. In spite of all the precautions, Manasa had her way. One of the snakes, sent by her, killed Lakshmindara. It was the custom that anyone who died of snake-bite was not cremated in the usual way but was allowed to float on a raft down the river, with the hope that the person could miraculously come back to life. Behula insisted on accompanying her dead husband on the raft ignoring all the pleas of others not to do so. They sailed for six months, passing village after village, the corpse began to decompose, the villagers

neg: Wood preservation of wood pests that could be transported internationally. Wood and bamboo can be buried in mud to help protect them from insects and decay. This practice is used widely in Vietnam to build farm houses consisting of a wooden structural frame, a bamboo roof frame and bamboo with mud mixed with rice hay for the walls. While wood in contact with soil will generally decompose more quickly than wood not in contact with it, it is possible that the predominantly clay soils prevalent in Vietnam provide a degree of mechanical protection against insect attack, which compensates for the accelerated rate

neg: Fluid thread breakup to take a Fourier transform of the disturbances to decompose the arbitrary disturbances into perturbations of various single wavelengths on the surface of the thread. In doing so, this allows one to determine which wavelengths of the disturbance will grow and which will decay in time. The growth and decay of wavelengths can be determined by examining the change in pressure a perturbation wavelength imposes on the interior of the fluid thread. Changes to the internal pressure of the thread are induced by capillary pressure as the free surface of the thread deforms. Capillary pressure is a function of the

neg: Fall of man assurance that "when there come unto you from Me a guidance, then whoso followeth My guidance, he will not go astray nor come to grief." In classic Zoroastrianism, humanity is created to withstand the forces of decay and destruction through good thoughts, words and deeds. Failure to do so actively leads to misery for the individual and for his family. This is also the moral of many of the stories of the Shahnameh, the key text of Persian mythology. The Alawites believed that they were once luminous stars worshipping ʿAlī ibn Abī Ṭālib in a world of light, but that

neg: ALICE experiment momentum. The ITS is so precise that particles which are generated by the decay of other particles with a long(~.1 mm before decay) life time can be identified by seeing that they do not originate from the point where the interaction has taken place (the "vertex" of the event) but rather from a point at a distance of as small as a tenth of a millimeter. This allows us to measure, for example, bottom quarks which decay into a relatively long-lived B-meson through "topological" cuts. The short-living heavy particles cover a very small distance before decaying. This system aims at

neg: Predictive engineering analytics as steel and aluminium, and traditional manufacturing methods, such as casting. New materials such as composites, behave differently when it comes to structural behavior, thermal behavior, fatigue behavior or noise insulation for example, and require dedicated modeling. On top of that, as design engineers do not always know all manufacturing complexities that come with using these new materials, it is possible that the "product as manufactured" is different from the "product as designed". Of course all changes need to be tracked, and possibly even an extra validation iteration needs to be done after manufacturing. Today's products include lots of sensors

neg: Decay-accelerating factor human enterovirus that was tested binds much more strongly to human DAF than to mouse or rat DAF. Echoviruses and coxsackie B viruses that use human decay-accelerating factor (DAF) as a receptor do not bind the rodent analogues of DAF. and DAF-Fc has yet to be tested in humans. Decay-accelerating factor Complement decay-accelerating factor, also known as CD55 or DAF, is a protein that, in humans, is encoded by the "CD55" gene. DAF regulates the complement system on the cell surface. It recognizes C4b and C3b fragments that are created during activation of C4 (classical or lectin pathway) or C3

neg: Island of stability 184 (Ubn, Ubq, and Ubh) are predicted to form spherical doubly magic nuclei and be stable with respect to fission. Calculations in a quantum tunneling model show that such superheavy nuclei would undergo alpha decay within microseconds or less. The manufacture of nuclei on the island of stability proves to be very difficult because the nuclei available as starting materials do not deliver the necessary sum of neutrons. For the synthesis of isotope 298 of flerovium, one could use an isotope of plutonium and one of calcium that together have a sum of at least 298 nucleons; for example, calcium-50

neg: Radioactive nanoparticle are common radioisotopes used for these purposes, with many others used as well. Radioactive nanoparticles can be produced by either synthesizing the nanoparticles directly from the radioactive materials, or by irradiating non-radioactive particles with neutrons or accelerated ions, sometimes "in situ". As with all nanoparticles, radioactive nanoparticles can also be naturally occurring or incidentally produced as a byproduct of industrial processes. The main source of naturally occurring nanomaterials containing radionuclides is the decay of radon gas, whose immediate decay products are non-gaseous elements that precipitate into nanoscale particles along with atmospheric dust and vapors. Minor natural sources include primordial radionuclides

neg: Betavoltaic device electrical applications where long life of the energy source is needed, such as implantable medical devices or military and space applications. Betavoltaics were invented in the 1970s. Some pacemakers in the 1970s used betavoltaics based on promethium, but were phased out as cheaper lithium batteries were developed. Early semiconducting materials weren't efficient at converting electrons from beta decay into usable current, so higher energy, more expensive—and potentially hazardous—isotopes were used. The more efficient semiconducting materials used today can be paired with relatively benign isotopes such as tritium, which produce less radiation. The Betacel was considered the first successfully commercialized betavoltaic

neg: John Olsen (Danish artist) raw materials, making use of branches, animal skulls or stuffed birds. His creations depict nature's decay, evoking the fragility of life and the imminence of death while giving death itself beauty in its own right. At the 1995 Venice Biennale, Olsen exhibited "Resonans", a large sculpture inspired by an armadillo shell, as well as many other items based on his favourite subjects and materials. Other works from the mid-1990s include drawings he created in the sauna where charcoal and chalk interact with sweat and steam, resulting in the reddish-brown works known as "Svedetegninger" (Sweat Drawings). In connection with John Olsen's

neg: Nuclear forensics of daughter nuclides. Chronometry is based on the concept that the composition of the nuclear material changes as samples are prepared and analyzed. This barrier can be substantial for species that decay quickly or whose daughter products put forth spectral interferences. The decay of U, for example, has a t~1.6x10years which is rapid in comparison to many species and yield Th, which emits an α particle that is isoenergetic, having the same energy, as the parent. To avoid this, freshly prepared samples as well as complementary analysis methods are used for confident nuclear materials characterization. The decay of nuclear samples

neg: Fluorescence-lifetime imaging microscopy This can be utilized for making non-intensity based measurements in chemical sensing. Fluorescence-lifetime imaging yields images with the intensity of each pixel determined by formula_4, which allows one to view contrast between materials with different fluorescence decay rates (even if those materials fluoresce at exactly the same wavelength), and also produces images which show changes in other decay pathways, such as in FRET imaging. Fluorescence lifetimes can be determined in the time domain by using a pulsed source. When a population of fluorophores is excited by an ultrashort or delta pulse of light, the time-resolved fluorescence will decay exponentially as

neg: Donald Sultan in sections with plaster. The plaster and tile may or may not be painted. The color often retains the gloss and unnatural lushness of the Polaroid photographs Sultan takes after he decides the still-life arrangement. The results are surprising and hip. The still lifes may not literally contain apples and oranges, but they do mix together very different, seemingly incompatible elements... Positive and negative, charred and pristine, ripeness and decay all nestle together..." Sultan's use of industrial materials in this way is striking and innovative, and Vivien Raynor has made this point in "The New York Times" stating that "Donald

neg: Design with memory also translated well back to English in the ways we thought about sustainable design - "Where do materials come from and where do they go next?” (Johnson interview, Sotokoto 2003) This collaboration subsequently led to a year long series of seminars for professional industrial designers and support for the 5th and 6th rounds of the Competition was provided by the Japanese Ministry of International Trade and Industry (MITI) together with other industry supporters such as Living Design Center OZONE in Tokyo. From 1994 to 2003 the Competition received over 1200 entries from over 20 countries with the 5th and 6th

neg: Lumber high moisture content enables fungal organisms to grow. The primary objective when addressing moisture loads is to keep water from entering the building envelope in the first place, and to balance the moisture content within the building itself. Moisture control by means of accepted design and construction details is a simple and practical method of protecting a wood-frame building against decay. For applications with a high risk of staying wet, designers specify durable materials such as naturally decay-resistant species or wood that has been treated with preservatives. Cladding, shingles, sill plates and exposed timbers or glulam beams are examples of

neg: Spin glass of magnetization versus time adequately. This slow decay is particular to spin glasses. Experimental measurements on the order of days have shown continual changes above the noise level of instrumentation. Spin glasses differ from ferromagnetic materials by the fact that after the external magnetic field is removed from a ferromagnetic substance, the magnetization remains indefinitely at the remanent value. Paramagnetic materials differ from spin glasses by the fact that, after the external magnetic field is removed, the magnetization rapidly falls to zero, with no remanent magnetization. The decay is rapid and exponential. If the sample is cooled below "T" in

neg: Powder angle of repose. Powder A powder is a dry, bulk solid composed of a large number of very fine particles that may flow freely when shaken or tilted. Powders are a special sub-class of granular materials, although the terms "powder" and "granular" are sometimes used to distinguish separate classes of material. In particular, "powders" refer to those granular materials that have the finer grain sizes, and that therefore have a greater tendency to form clumps when flowing. "Granulars" refers to the coarser granular materials that do not tend to form clumps except when wet. Many manufactured goods come in powder

neg: Powder Powder A powder is a dry, bulk solid composed of a large number of very fine particles that may flow freely when shaken or tilted. Powders are a special sub-class of granular materials, although the terms "powder" and "granular" are sometimes used to distinguish separate classes of material. In particular, "powders" refer to those granular materials that have the finer grain sizes, and that therefore have a greater tendency to form clumps when flowing. "Granulars" refers to the coarser granular materials that do not tend to form clumps except when wet. Many manufactured goods come in powder form, such as

neg: Isotopes of iodine iodine-135 can temporarily preclude a shut-down reactor from restarting. This is known as xenon-poisoning or "falling into an iodine pit". Iodine fission-produced isotopes not discussed above (iodine-128, iodine-130, iodine-132, and iodine-133) have a half lives of a couple of hours or minutes, rendering them almost useless in other applicable areas. Those mentioned are neutron-rich and so go through beta decay to their xenon counterparts. Iodine-128 (25 min half-life) can decay to either tellurium-128 by electron capture, or to xenon-128 by beta decay. It has a specific radioactivity of 2.177 x 10 TBq/g. Colloquially, radioactive materials can be described as "hot,"

neg: Trace Decay has a rifle trained on our backside." He gave the episode a 3.5 out of 5. Erik Kain of "Forbes" also reviewed the episode, saying, "Where does it all go from here? I don't know, honestly. What I do know is that I can't wait to find out. Without doubt, "Westworld" is the best thing on TV right now." Trace Decay "Trace Decay" is the eighth episode of the HBO science fiction thriller television series "Westworld". The episode aired on November 20, 2016. The episode received very positive reviews from critics. Bernard is distraught over having been ordered to kill

neg: Petroleum resins, but kerogen formation occurred in a more complex manner due to a bigger variety of reactants. The total process of kerogen formation from the beginning of anaerobic decay is called diagenesis, a word that means a transformation of materials by dissolution and recombination of their constituents. Kerogen formation continued to the depth of about 1 km from the Earth's surface where temperatures may reach around 50 °C. Kerogen formation represents a halfway point between organic matter and fossil fuels: kerogen can be exposed to oxygen, oxidize and thus be lost or it could be buried deeper inside the Earth's

neg: Leonardo Drew or constructed." Leonardo Drew Leonardo Drew is a contemporary artist based in Brooklyn, New York. He creates sculptures from natural materials and through processes of oxidation, burning, and decay, Drew transforms these objects into massive sculptures that critique social injustices and the cyclical nature of existence. Leonardo Drew was born in Tallahassee, Florida, but was raised in the projects of Bridgeport, Connecticut, where the city dump occupied every view of his apartment. During his early childhood, Drew often found himself there mining through and creating works from discarded remnants, giving them new meaning. In "Existed", “Dust to Dust by Allen

neg: Neutral particle oscillation words, direct CP violation is observed in the asymmetry between the two modes of decay. If the final state (say formula_52) is a CP eigenstate (for example ), then there are two different decay amplitudes corresponding to two different decay paths: formula_160 and, formula_161. CP violation can then result from the interference of these two contributions to the decay as one mode involves only decay and the other oscillation and decay. The above description refers to flavor (or strangeness) eigenstates and energy (or CP) eigenstates. But which of them represents the "real" particle? What do we really detect in a

neg: Subbase (pavement) which can be scrapped off and after checking that the subbase is still in good condition, a new layer can be applied Unbound granular materials are usually crushed stone, crushed slag or concrete, or slate. Cement-bound materials come in multiple types. Mass concrete is used where exceptional loads are expected, with thickness usually , and optional reinforcement with steel mesh or polymer fibers. Other cement bound materials (CBM), with less strength but also lower cost, are used. They are rated by strength, from the weakest CBM 1 (also formerly known as soil cement) through CBM 2 to CBM 3, 4,

neg: Growth and decay problem Growth and decay problem This article discusses an important problem from application of view. The document does not go into much depth but it has enough information to make you familiar with these problem.The result of this problem is used in many fields like nuclear chemistry, biology,etc. in one or another form. In our daily life, often we come across problems related with growth and decay like decay of organic matter, growth of plants,etc.But some growth and decay phenomenon can be described in terms of differential equations like decay of radioactive element like Uranium, growth of certain bacteria,etc. How this

neg: Dental restoration (2) placement of these materials. The process of preparation usually involves cutting the tooth with a rotary dental handpiece and dental burrs to make space for the planned restorative materials and to remove any dental decay or portions of the tooth that are structurally unsound. If permanent restoration cannot be carried out immediately after tooth preparation, temporary restoration may be performed. The prepared tooth, ready for placement of restorative materials, is generally called a "tooth preparation". Materials used may be gold, amalgam, dental composites, glass ionomer cement, or porcelain, among others. Preparations may be intracoronal or extracoronal. Intracoronal preparations are

neg: Titanium foam separated by a thick, light-weight core and are most commonly composed of balsa-wood, foamed polymers, glue-bonded aluminum or Nomex (paper) honeycombs. Typically, the cores are combined with reinforcing fibers to increase their shear modulus. Indeed, carbon fiber-reinforced polymers exhibit the highest specific stiffness and strength of these materials. However, polymers decompose at low temperatures; thus employment of the aforementioned materials pose inherent challenges due to the limited range of temperature they may be utilized within as well as their moisture-dependent properties. The largest and most inadequately predicted failure within the core results from strain localization. Strain localization refers to the

neg: Extraterrestrial materials have more than one isotope on which to carry the signature of nuclear processes (xenon has many), and finally because they are relatively easy to extract from solid materials by simple heating. As a result, they play a pivotal role in the unfolding drama of extraterrestrial materials study. Some clues to moving further might be found in this book and this article. Isotopic abundances provide important clues to the date of events that allowed a material to begin accumulating gaseous decay byproducts, or that allowed incident radiation to begin transmuting elements. Because of the harsh radiations, unusual starting compositions, and

neg: Ecosystem ecology processes which likely occur during decomposition. For instance, proteins, sugars and lipids decompose exponentially, but lignin decays at a more linear rate Thus, litter decay is inaccurately predicted by simplistic models. A simple alternative model presented in Figure 5C shows significantly more rapid decomposition that the standard model of figure 4B. Better understanding of decomposition models is an important research area of ecosystem ecology because this process is closely tied to nutrient supply and the overall capacity of ecosystems to sequester CO from the atmosphere. Trophic dynamics refers to process of energy and nutrient transfer between organisms. Trophic dynamics is

neg: Stock solution Stock solution A stock solution is a concentrated solution that will be diluted to some lower concentration for actual use. Stock solutions are used to save preparation time, conserve materials, reduce storage space, and improve the accuracy with which working lower concentration solutions are prepared. In chemistry, a stock solution is a large volume of common reagent, such as hydrochloric acid or sodium hydroxide, at a standardized concentration. This term is commonly used in analytical chemistry for procedures such as titrations, where it is important that exact concentrations of solutions are used. Stock solutions do not necessarily come in concentrations

neg: Polysilazane structure of polysilazanes. Silazane copolymers are normally produced from ammonolyses of chlorosilane mixtures. In this chemical reaction, different chlorosilanes react at similar rates so that the monomers are statistically distributed in the copolymer. Ammonia and chlorosilanes, both readily available and low-priced, are used as starting materials in the synthesis of polysilazanes. In the ammonolysis reaction, large quantities of ammonium chloride are produced and must be removed from the reaction mixture. In the laboratory, the reaction is normally carried out in a dry organic solvent (polysilazanes decompose in the presence of water or moisture) and the ammonium chloride is removed by