ChemTEB Classification Datasets
Collection
Chemical Classification Datasets for Evaluating Text Embedding Models • 19 items • Updated
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In 2009, a Chinese cement company (in Tongchuan, Shaanxi Province) was demolishing an old, unused cement plant and did not follow standards for handling radioactive materials. This caused some caesium-137 from a measuring instrument to be included with eight truckloads of scrap metal on its way to a steel mill, where t... | 1 | Fission Products + Nuclear Fission |
In nuclear physics, a nuclear chain reaction occurs when one single nuclear reaction causes an average of one or more subsequent nuclear reactions, thus leading to the possibility of a self-propagating series or "positive feedback loop" of these reactions. The specific nuclear reaction may be the fission of heavy isoto... | 1 | Fission Products + Nuclear Fission |
Mass-independent isotope fractionation or Non-mass-dependent fractionation (NMD), refers to any chemical or physical process that acts to separate isotopes, where the amount of separation does not scale in proportion with the difference in the masses of the isotopes. Most isotopic fractionations (including typical kin... | 0 | Isotopes |
Some fission products (such as Cs) are used in medical and industrial radioactive sources.
TcO (pertechnetate) ion can react with steel surfaces to form a corrosion resistant layer. In this way these metaloxo anions act as anodic corrosion inhibitors - it renders the steel surface passive. The formation of TcO on steel... | 1 | Fission Products + Nuclear Fission |
The mass-independent distribution of isotopes in stratospheric ozone can be transferred to carbon dioxide (CO). This anomalous isotopic composition in CO can be used to quantify gross primary production, the uptake of CO by vegetation through photosynthesis. This effect of terrestrial vegetation on the isotopic signatu... | 0 | Isotopes |
In physics, natural abundance (NA) refers to the abundance of isotopes of a chemical element as naturally found on a planet. The relative atomic mass (a weighted average, weighted by mole-fraction abundance figures) of these isotopes is the atomic weight listed for the element in the periodic table. The abundance of an... | 0 | Isotopes |
Deuterium-depleted water can be produced in laboratories and factories. Various technologies are used for its production, such as electrolysis, distillation (low-temperature vacuum rectification), desalination from seawater, Girdler sulfide process, and catalytic exchange. | 0 | Isotopes |
Sr is used as a blade inspection method in some helicopters with hollow blade spars to indicate if a crack has formed. | 1 | Fission Products + Nuclear Fission |
Singly substituted isotopologues may be used for nuclear magnetic resonance experiments, where deuterated solvents such as deuterated chloroform (CDCl) do not interfere with the solutes' H signals, and in investigations of the kinetic isotope effect. | 0 | Isotopes |
Gilbert N. Lewis was the first to discover that heavy water inhibits (retards) seed growth (1933). His experiments with tobacco seeds showed that cultivation of cells on heavy water dramatically accelerates the aging process and leads to lethal results. | 0 | Isotopes |
A number of datable minerals occur as common detrital grains in sandstones, and if the strata have not been buried too deeply, these minerals grains retain information about the source rock. Fission track analysis of these minerals provides information about the thermal evolution of the source rocks and therefore can ... | 1 | Fission Products + Nuclear Fission |
In order to get more reasonable values for the nuclear masses in the liquid drop model, it is necessary to include shell effects. Soviet physicist Vilen Strutinsky proposed such a method using "shell correction" and corrections for nuclear pairing to the liquid drop model. In this method, the total energy of the nucleu... | 1 | Fission Products + Nuclear Fission |
An emerging body of work highlights the application potential for clumped isotopes to reconstruct temperature and fluid properties in hydrothermal ore deposits. In mineral exploration, delineation of the heat footprint around an ore body provides critical insight into the processes that drive transport and deposition o... | 0 | Isotopes |
Fission track dating is a radiometric dating technique based on analyses of the damage trails, or tracks, left by fission fragments in certain uranium-bearing minerals and glasses. Fission-track dating is a relatively simple method of radiometric dating that has made a significant impact on understanding the thermal h... | 1 | Fission Products + Nuclear Fission |
The ratio of H, also known as deuterium, to H has been studied in both plant and animal tissue. Hydrogen isotopes in plant tissue are correlated with local water values but vary based on fractionation during photosynthesis, transpiration, and other processes in the formation of cellulose. A study on the isotope ratios ... | 0 | Isotopes |
# Extract from carbonates by reaction with anhydrous phosphoric acid. (there is no direct way to measure the abundance of COs in with high enough precision). The phosphoric acid temperature is often held between 25° and 90 °C and can be as high as 110 °C.
# Purify the that has been extracted. This step removes contam... | 0 | Isotopes |
Similar investigations into the isotopic ratios of ruthenium at Oklo found a much higher concentration than otherwise naturally occurring (27–30% vs. 12.7%). This anomaly could be explained by the decay of to . In the bar chart the normal natural isotope signature of ruthenium is compared with that for fission produc... | 1 | Fission Products + Nuclear Fission |
Nuclear fission products are the atomic fragments left after a large atomic nucleus undergoes nuclear fission. Typically, a large nucleus like that of uranium fissions by splitting into two smaller nuclei, along with a few neutrons, the release of heat energy (kinetic energy of the nuclei), and gamma rays. The two smal... | 1 | Fission Products + Nuclear Fission |
The terminology of isotopic reference materials is not applied consistently across subfields of isotope geochemistry or even between individual laboratories. The terminology defined below comes from Gröening et al. (1999) and Gröening (2004). Reference materials are the basis for accuracy across many different types of... | 0 | Isotopes |
It is expected that some continual improvement of experimental sensitivity will allow discovery of very mild radioactivity (instability) of some isotopes that are considered to be stable today. For example, in 2003 it was reported that bismuth-209 (the only primordial isotope of bismuth) is very mildly radioactive, wit... | 0 | Isotopes |
Deuterium-depleted water (DDW) is water which has a lower concentration of deuterium than occurs naturally at sea level on Earth.
DDW is sometimes known as light water or protium water, although "light water" has long referred to ordinary water, specifically in nuclear reactors. | 0 | Isotopes |
Sulfur has four stable isotopes, S, S, S, and S, of which S is the most abundant by a large margin due to the fact it is created by the very common C in supernovas. Sulfur isotope ratios are almost always expressed as ratios relative to S due to this major relative abundance (95.0%). Sulfur isotope fractionations are u... | 0 | Isotopes |
*The use of Iodine-131 as a poison – used in small doses over a period of time to disrupt a persons ability to think and tell right from wrong – played a central role in the episode "The Case of the Melancholy Marksman" of the long-running CBS TV series Perry Mason' (season 5, episode 24, first broadcast Ma... | 1 | Fission Products + Nuclear Fission |
Amino acids are a key nutrient in ecosystems. Some are essential to animals, meaning that these organisms cannot synthesize them de novo. Instead, animals rely on their diet to acquire these molecules, creating strong interdependencies between animals and organisms with complete amino acid synthesis capabilities. In a ... | 0 | Isotopes |
Some unstable isotopes which occur naturally (such as , , and ) are not primordial, as they must be constantly regenerated. This occurs by cosmic radiation (in the case of cosmogenic nuclides such as and ), or (rarely) by such processes as geonuclear transmutation (neutron capture of uranium in the case of and ). Oth... | 0 | Isotopes |
The prompt neutron lifetime, , is the average time between the emission of neutrons and either their absorption in the system or their escape from the system. The neutrons that occur directly from fission are called "prompt neutrons", and the ones that are a result of radioactive decay of fission fragments are called "... | 1 | Fission Products + Nuclear Fission |
I, with a half-life of 8 days, is a hazard from nuclear fallout because iodine concentrates in the thyroid gland. See also Radiation effects from Fukushima Daiichi nuclear disaster#Iodine-131 and
Downwinders#Nevada.
In common with Sr, I is used for the treatment of cancer. A small dose of I can be used in a thyroid fun... | 1 | Fission Products + Nuclear Fission |
Some isotopes/nuclides are radioactive, and are therefore referred to as radioisotopes or radionuclides, whereas others have never been observed to decay radioactively and are referred to as stable isotopes or stable nuclides. For example, is a radioactive form of carbon, whereas and are stable isotopes. There are a... | 0 | Isotopes |
The addition of lime to soils which are poor in calcium can reduce the uptake of strontium by plants. Likewise in areas where the soil is low in potassium, the addition of a potassium fertilizer can discourage the uptake of cesium into plants. However such treatments with either lime or potash should not be undertaken... | 1 | Fission Products + Nuclear Fission |
On 3 and 4 March 2016, unusually high levels of caesium-137 were detected in the air in Helsinki, Finland. According to STUK, the country's nuclear regulator, measurements showed 4,000 μBq/m – about 1,000 times the usual level. An investigation by the agency traced the source to a building from which STUK and a radioac... | 1 | Fission Products + Nuclear Fission |
Xe is the heaviest noble gas in the Earth's atmosphere. It has seven stable isotopes (Xe,Xe,Xe,Xe,Xe, Xe, Xe) and two isotopes (Xe, Xe) with long-lived half-lives. Xe has four synthetic radioisotopes with very short half-lives, usually less than one month.
Xenon-129 can be used to examine the early history of the Earth... | 0 | Isotopes |
In the Goiânia accident of 1987, an improperly disposed of radiation therapy system from an abandoned clinic in Goiânia, Brazil, was removed, then cracked to be sold in junkyards. The glowing caesium salt was then to be sold to curious, unadvised buyers. This led to four confirmed deaths and several serious injuries fr... | 1 | Fission Products + Nuclear Fission |
NAIL-MS can be used to produce stable isotope labeled internal standards (ISTD). Therefore, cells are grown in medium which results in complete labeling of all nucleosides. The purified mix of nucleosides can then be used as ISTD which is needed for accurate absolute quantification of nucleosides by mass spectrometry. ... | 0 | Isotopes |
According to the IsoRes hypothesis, there are certain resonance isotopic compositions at which terrestrial organisms thrive best. Curiously, average terrestrial isotopic compositions are very close to a resonance affecting a large class of amino acids and polypeptides, the molecules of outmost importance for life. Thus... | 0 | Isotopes |
The radioactive decay of strontium-90 generates a significant amount of heat, 0.95 W/g in the form of pure strontium metal or approximately 0.460 W/g as strontium titanatePu. It is used as a heat source in many Russian/Soviet radioisotope thermoelectric generators, usually in the form of strontium titanate. It was also... | 1 | Fission Products + Nuclear Fission |
Primitive meteorites have been studied using measurements of Δ47. These analyses also assume that the primary isotopic signature of the sample has been lost. In this case, measurements of Δ47 instead provide information on the high-temperature event that isotopically reset the sample. Existing Δ47 analyses on primit... | 0 | Isotopes |
Sr is a product of nuclear fission. It is present in significant amount in spent nuclear fuel, in radioactive waste from nuclear reactors and in nuclear fallout from nuclear tests.
For thermal neutron fission as in today's nuclear power plants, the fission product yield from uranium-235 is 5.7%, from uranium-233 6.6%, ... | 1 | Fission Products + Nuclear Fission |
Phosphoenolpyruvate carboxylase (PEPC) is an enzyme that combines bicarbonate and phosphoenolpyruvate (PEP) to form the four-carbon acid, oxaloacetate. It is an important enzyme in C4 photosynthesis and anaplerotic pathways. It is also responsible for the position-specific enrichment of oxaloacetate, due to the equilib... | 0 | Isotopes |
Compared with solar xenon, Earths atmospheric Xe is enriched in heavy isotopes by 3 to 4% per atomic mass unit (amu). However, the total abundance of xenon gas is depleted by one order of magnitude relative to other noble gases. The elemental depletion while relative enrichment in heavy isotopes is called the "Xenon pa... | 0 | Isotopes |
Stable isotopic analysis has also been used for tracing the geographical origin of food, timber, and in tracing the sources and fates of nitrates in the environment. | 0 | Isotopes |
A half life is the time it takes half of the radiation of a specific substance to decay. A large amount of short-lived isotopes such as Zr are present in bomb fallout. This isotope and other short-lived isotopes are constantly generated in a power reactor, but because the criticality occurs over a long length of time, ... | 1 | Fission Products + Nuclear Fission |
Se-79, half-life of 327k years, is one of the long-lived fission products. Given the stability of its next lighter and heavier isotopes and the high cross section those isotopes exhibit for various neutron reactions, it is likely that the relatively low yield is due to Se-79 being destroyed in the reactor to an appreci... | 1 | Fission Products + Nuclear Fission |
As of 2009 the total amount in the atmosphere is estimated at 5500 PBq due to anthropogenic sources. At the end of the year 2000, it was estimated to be 4800 PBq, and in 1973, an estimated 1961 PBq (53 megacuries). The most important of these human sources is nuclear fuel reprocessing, as krypton-85 is one of the seven... | 1 | Fission Products + Nuclear Fission |
A Xe atom that does not capture a neutron undergoes beta decay to Cs, one of the 7 long-lived fission products, while a Xe that does capture a neutron becomes almost-stable Xe.
The probability of capturing a neutron before decay varies with the neutron flux, which itself depends on the kind of reactor, fuel enrichment ... | 1 | Fission Products + Nuclear Fission |
Algae has shown selectivity for strontium in studies, where most plants used in bioremediation have not shown selectivity between calcium and strontium, often becoming saturated with calcium, which is greater in quantity and also present in nuclear waste.
Researchers have looked at the bioaccumulation of strontium by S... | 1 | Fission Products + Nuclear Fission |
Nuclear magnetic resonance observes small differences in molecular reactions to oscillating magnetic fields. It is able to characterize atoms with active nuclides that have a non-zero nuclear spin (e.g., C, H, O Cl, N, Cl), which makes it particularly useful for identifying certain isotopes. In typical proton or 13C NM... | 0 | Isotopes |
Calibration materials are compounds whose isotopic composition is known extremely well relative to the primary reference materials or which define the isotopic composition of the primary reference materials but are not the isotopic ratios to which data are reported in the scientific literature. For example, the calibra... | 0 | Isotopes |
Fast fission is fission that occurs when a heavy atom absorbs a high-energy neutron, called a fast neutron, and splits. Most fissionable materials need thermal neutrons, which move more slowly. | 1 | Fission Products + Nuclear Fission |
Isotopes are different forms of elements; they have a different number of neutrons in the nucleus, meaning they have very similar chemical properties, but different mass. The weight difference means that some isotopes are discriminated against in chemical processes – for example, plants find it easier to incorporate t... | 0 | Isotopes |
Because of the carcinogenicity of its beta radiation in the thyroid in small doses, I-131 is rarely used primarily or solely for diagnosis (although in the past this was more common due to this isotope's relative ease of production and low expense). Instead the more purely gamma-emitting radioiodine iodine-123 is used ... | 1 | Fission Products + Nuclear Fission |
The fission process can be understood when a nucleus with some equilibrium deformation absorbs energy (through neutron capture, for example), becomes excited and deforms to a configuration known as the "transition state" or "saddle point" configuration. As the nucleus deforms, the nuclear Coulomb energy decreases while... | 1 | Fission Products + Nuclear Fission |
Chromatography facilitates separation of distinct molecules within a mixture based on their respective chemical properties, and how those properties interact with the substrate coating the chromatographic column. This separation can happen “on-line,” during the measurement itself, or prior to measurements to isolate a ... | 0 | Isotopes |
A recent international project has developed and determined the hydrogen, carbon, and nitrogen isotopic composition of 19 organic isotopic reference materials, now available from USGS, IAEA, and Indiana University. These reference materials span a large range of δH (-210.8‰ to +397.0‰), δC (-40.81‰ to +0.49‰), and δN (... | 0 | Isotopes |
I is one of the seven long-lived fission products that are produced in significant amounts. Its yield is 0.706% per fission of U. Larger proportions of other iodine isotopes such as I are produced, but because these all have short half-lives, iodine in cooled spent nuclear fuel consists of about 5/6 I and 1/6 the only ... | 1 | Fission Products + Nuclear Fission |
Several lanthanides produced at CERN-MEDICIS, samarium and terbium, are of interest for targeted therapy alike lutetium already used in the clinics. Lutetium emits low energy β particles with a short range, used for irradiation of smaller volume tumor targets. Terbium-149 emits short-range alpha particles, gamma-rays a... | 0 | Isotopes |
Most I production is from neutron irradiation of a natural tellurium target in a nuclear reactor. Irradiation of natural tellurium produces almost entirely I as the only radionuclide with a half-life longer than hours, since most lighter isotopes of tellurium become heavier stable isotopes, or else stable iodine or xen... | 1 | Fission Products + Nuclear Fission |
There are some disputes about using I-Xe dating to estimate the Xe closure time. First, in the early solar system, planetesimals collided and grew into larger bodies that accreted to form the Earth. But there could be a 10 to 10 years time gap in Xe closure time between the Earths inner and outer regions. Some research... | 0 | Isotopes |
The fissile isotope uranium-235 in its natural concentration is unfit for the vast majority of nuclear reactors. In order to be prepared for use as fuel in energy production, it must be enriched. The enrichment process does not apply to plutonium. Reactor-grade plutonium is created as a byproduct of neutron interaction... | 1 | Fission Products + Nuclear Fission |
The mean generation time, Λ, is the average time from a neutron emission to a capture that results in fission. The mean generation time is different from the prompt neutron lifetime because the mean generation time only includes neutron absorptions that lead to fission reactions (not other absorption reactions). The tw... | 1 | Fission Products + Nuclear Fission |
In some cases, additional functional groups will need to be added to molecules to facilitate the other separation and analysis methods. Derivatization can change the properties of an analyte; for instance, it would make a polar and non-volatile compound non-polar and more volatile, which would be necessary for analysis... | 0 | Isotopes |
While there is no enrichment of S between trophic levels, the stable isotope can be useful in distinguishing benthic vs. pelagic producers and marsh vs. phytoplankton producers. Similar to C, it can also help distinguish between different phytoplankton as the key primary producers in food webs. The differences between ... | 0 | Isotopes |
Multiple substituted isotopologues may be used for nuclear magnetic resonance or mass spectrometry experiments, where isotopologues are used to elucidate metabolic pathways in a qualitative (detect new pathways) or quantitative (detect quantitative share of a pathway) approach. A popular example in biochemistry is the ... | 0 | Isotopes |
Molecules made up of elements with multiple isotopes can vary in their isotopic composition, these different mass molecules are called isotopologues. Isotopologues such as COO, contain multiple heavy isotopes of oxygen substituting for the more common O, and are termed multiply-substituted isotopologues. The multiply-s... | 0 | Isotopes |
In March 2015, the Norwegian University of Tromsø lost 8 radioactive samples, including samples of caesium-137, americium-241, and strontium-90. The samples were moved out of a secure location to be used for education. When the samples were supposed to be returned, the university was unable to find them. , the samples ... | 1 | Fission Products + Nuclear Fission |
Cumulative fission yields give the amounts of nuclides produced either directly in the fission or by decay of other nuclides. | 1 | Fission Products + Nuclear Fission |
A neutral atom has the same number of electrons as protons. Thus different isotopes of a given element all have the same number of electrons and share a similar electronic structure. Because the chemical behavior of an atom is largely determined by its electronic structure, different isotopes exhibit nearly identical c... | 0 | Isotopes |
In 1960, physicist John H. Reynolds discovered that certain meteorites contained an isotopic anomaly in the form of an overabundance of Xe. He inferred that this must be a decay product of long-decayed radioactive I. This isotope is produced in quantity in nature only in supernova explosions. As the half-life of I is c... | 1 | Fission Products + Nuclear Fission |
A mononuclidic element or monotopic element is one of the 21 chemical elements that is found naturally on Earth essentially as a single nuclide (which may, or may not, be a stable nuclide). This single nuclide will have a characteristic atomic mass. Thus, the element's natural isotopic abundance is dominated by one iso... | 0 | Isotopes |
Fast neutron reactors use fast fission to produce energy, unlike most nuclear reactors. In a conventional reactor, a moderator is needed to slow down the neutrons so that they are more likely to fission atoms. A fast neutron reactor uses fast neutrons, so it does not use a moderator. Moderators may absorb a lot of neut... | 1 | Fission Products + Nuclear Fission |
The Kramatorsk radiological accident happened in 1989 when a small capsule 8x4 mm in size of caesium-137 was found inside the concrete wall of an apartment building in Kramatorsk, Ukrainian SSR. It is believed that the capsule, originally a part of a measurement device, was lost in the late 1970s and ended up mixed wit... | 1 | Fission Products + Nuclear Fission |
The atomic mass (m) of an isotope (nuclide) is determined mainly by its mass number (i.e. number of nucleons in its nucleus). Small corrections are due to the binding energy of the nucleus (see mass defect), the slight difference in mass between proton and neutron, and the mass of the electrons associated with the atom... | 0 | Isotopes |
The biosynthesis of fatty acids begins with acetyl-CoA precursors that are brought together to make long straight chain lipids. Acetyl-CoA is produced in aerobic organisms by pyruvate dehydrogenase, an enzyme that has been shown to express a large, 2.3% isotope effect on the C2 site of pyruvate and a small fractionatio... | 0 | Isotopes |
The gun method has also been applied for nuclear artillery shells, since the simpler design can be more easily engineered to withstand the rapid acceleration and g-forces imparted by an artillery gun, and since the smaller diameter of the gun-type design can be relatively easily fitted to projectiles that can be fired ... | 1 | Fission Products + Nuclear Fission |
All of the known 251 stable nuclides, plus another 35 nuclides that have half-lives long enough to have survived from the formation of the Earth, occur as primordial nuclides. These 35 primordial radionuclides represent isotopes of 28 separate elements.
Cadmium, tellurium, xenon, neodymium, samarium, osmium, and uraniu... | 0 | Isotopes |
Caesium-137 has a half-life of about 30.05 years.
About 94.6% decays by beta emission to a metastable nuclear isomer of barium: barium-137m (Ba, Ba-137m). The remainder directly populates the ground state of Ba, which is stable. Barium-137m has a half-life of about 153 seconds, and is responsible for all of the gamma r... | 1 | Fission Products + Nuclear Fission |
Bombs in the arctic area of Novaja Zemlja and bombs detonated in or near the stratosphere released cesium-137 that landed in upper Lapland, Finland. Measurements of cesium-137 in 1960's was reportedly 45,000 becquerels. Figures from 2011 have a mid range of about 1,100 becquerels, but strangely, cancer cases are no mor... | 1 | Fission Products + Nuclear Fission |
Fallout comes in two varieties. The first is a small amount of carcinogenic material with a long half-life. The second, depending on the height of detonation, is a large quantity of radioactive dust and sand with a short half-life.
All nuclear explosions produce fission products, un-fissioned nuclear material, and weap... | 1 | Fission Products + Nuclear Fission |
Chemical reactions in biological processes are controlled by enzymes that catalyze the conversion of substrate to product. Since enzymes can alter the transition state structure for reactions, they also change kinetic and equilibrium isotope effects. Placed in the context of a metabolism, the expression of isotope eff... | 0 | Isotopes |
Natural isotopes are either stable isotopes or radioactive isotopes that have a sufficiently long half-life to allow them to exist in substantial concentrations in the Earth (such as bismuth-209, with a half-life of 1.9 years, potassium-40 with a half-life of 1.251(3) years), daughter products of those isotopes (such a... | 0 | Isotopes |
Analyses carried out at Pierrelatte and Cadarache showed that magnesium uranates (or yellow cakes) from Gabon had a variable but constant U depletion. On July 7, 1972, researchers at Cadarache discovered an anomaly in uranium ore from Oklo in Gabon. Its U content was much lower than usual. Isotopic analyses revealed th... | 1 | Fission Products + Nuclear Fission |
Primary reference materials define the scales on which isotopic ratios are reported. This can mean a material that historically defined an isotopic scale, such as Vienna Standard Mean Ocean Water (VSMOW) for hydrogen isotopes, even if that material is not currently in use. Alternatively, it can mean a material that onl... | 0 | Isotopes |
The IsoRes hypothesis has been tested experimentally by means of growth of E. coli and found to be supported by extremely strong statistics (p ). Particular strong evidence of faster growth was found for the “super-resonance”.
Fig. 1. 2D plot of molecular masses of 3000 E. coli tryptic peptides. A – terrestrial isotopi... | 0 | Isotopes |
Late or delayed effects of radiation occur following a wide range of doses and dose rates. Delayed effects may appear months to years after irradiation and include a wide variety of effects involving almost all tissues or organs. Some of the possible delayed consequences of radiation injury, with the rates above the ba... | 1 | Fission Products + Nuclear Fission |
CERN-MEDical Isotopes Collected from ISOLDE (MEDICIS) is a facility located in the Isotope Separator Online DEvice (ISOLDE) facility at CERN, designed to produce high-purity isotopes for developing the practice of patient diagnosis and treatment. The facility was initiated in 2010, with its first radioisotopes (terbium... | 0 | Isotopes |
As of today and for the next few hundred years or so, caesium-137 and strontium-90 continue to be the principal source of radiation in the zone of alienation around the Chernobyl nuclear power plant, and pose the greatest risk to health, owing to their approximately 30 year half-life and biological uptake. The mean con... | 1 | Fission Products + Nuclear Fission |
In chemistry, isotopologues are molecules that differ only in their isotopic composition. They have the same chemical formula and bonding arrangement of atoms, but at least one atom has a different number of neutrons than the parent.
An example is water, whose hydrogen-related isotopologues are: "light water" (HOH or )... | 0 | Isotopes |
Because of the relative rarity of the heavy isotopes of C, H, and O, isotope-ratio mass spectrometry (IRMS) of doubly substituted species requires larger volumes of sample gas and longer analysis times than traditional stable isotope measurements, thereby requiring extremely stable instrumentation. In addition, the dou... | 0 | Isotopes |
In nuclear engineering, fissile material is material that can undergo nuclear fission when struck by a neutron of low energy. A self-sustaining thermal chain reaction can only be achieved with fissile material. The predominant neutron energy in a system may be typified by either slow neutrons (i.e., a thermal system)... | 1 | Fission Products + Nuclear Fission |
The δ values and absolute isotope ratios of common reference materials are summarized in Table 1 and described in more detail below. Alternative values for the absolute isotopic ratios of reference materials, differing only modestly from those in Table 1, are presented in Table 2.5 of Sharp (2007) (a [http://digitalrep... | 0 | Isotopes |
Isotope analysis has widespread applicability in the natural sciences. These include numerous applications in the biological, earth and environmental sciences. | 0 | Isotopes |
Fission products have half-lives of 90 years (samarium-151) or less, except for seven long-lived fission products that have half lives of 211,100 years (technetium-99) or more. Therefore, the total radioactivity of a mixture of pure fission products decreases rapidly for the first several hundred years (controlled by t... | 1 | Fission Products + Nuclear Fission |
Commercial nuclear fission reactors are operated in the otherwise self-extinguishing prompt subcritical state. Certain fission products decay over seconds to minutes, producing additional delayed neutrons crucial to sustaining criticality. An example is bromine-87 with a half-life of about a minute. Operating in this ... | 1 | Fission Products + Nuclear Fission |
Nuclear fallout can occur due to a number of different sources. One of the most common potential sources of nuclear fallout is that of nuclear reactors. Because of this, steps must be taken to ensure the risk of nuclear fallout at nuclear reactors is controlled.
In the 1950s and 60s, the United States Atomic Energy Co... | 1 | Fission Products + Nuclear Fission |
I is not deliberately produced for any practical purposes. However, its long half-life and its relative mobility in the environment have made it useful for a variety of dating applications. These include identifying older groundwaters based on the amount of natural I (or its Xe decay product) present, as well as iden... | 1 | Fission Products + Nuclear Fission |
Chemical chain reactions were first proposed by German chemist Max Bodenstein in 1913, and were reasonably well understood before nuclear chain reactions were proposed. It was understood that chemical chain reactions were responsible for exponentially increasing rates in reactions, such as produced in chemical explosio... | 1 | Fission Products + Nuclear Fission |
The MEDICIS facility is located in the extension of building 179 at the CERN Meyrin site, next to the ISOLDE building. The facility was established by CERN in 2010, along with contributions from the CERN Knowledge Transfer Fund, as well as receiving a European Commission Marie-Skłodowska-Curie training grant under the ... | 0 | Isotopes |
Deuterium-depleted water has a lower concentration of deuterium (H) than occurs in nature at sea level. Deuterium is a naturally-occurring, stable (non-radioactive) isotope of hydrogen with a nucleus consisting of one proton and one neutron. The nucleus of ordinary hydrogen (protium) consists of one proton only, and no... | 0 | Isotopes |
Oxygen isotopic ratios are commonly compared to both the VSMOW and the VPDB references. Traditionally oxygen in water is reported relative to VSMOW while oxygen liberated from carbonate rocks or other geologic archives is reported relative to VPDB. As in the case of hydrogen, the oxygen isotopic scale is defined by two... | 0 | Isotopes |
Nuclear fallout is the residual radioactive material propelled into the upper atmosphere following a nuclear blast, so called because it "falls out" of the sky after the explosion and the shock wave has passed. It commonly refers to the radioactive dust and ash created when a nuclear weapon explodes. The amount and spr... | 1 | Fission Products + Nuclear Fission |
Tc, half-life 211k years, is produced at a yield of about 6% per fission; see also the main fission products page. It is also produced (via the short lived nuclear isomer Technetium-99m) as a decay product of Molybdenum-99. Technetium is particularly mobile in the environment as it forms negatively charged pertechnetat... | 1 | Fission Products + Nuclear Fission |
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Wikipedia Isotopes vs Nuclear Fission Products Binary Classification
This dataset is derived from the English Wikipedia articles and is designed for binary text classification tasks in the field of nuclear chemistry and physics. The dataset is divided into two classes based on the thematic content of the articles:
Isotopes: This class includes articles that focus on isotopes, which are variants of a particular chemical element that have the same number of protons but different numbers of neutrons. Topics may cover the properties, applications, and significance of various isotopes in fields such as medicine, archaeology, and nuclear energy.
Nuclear Fission Products: This class comprises articles related to:
- Fission Products: Articles that discuss the fragments left after a nucleus undergoes fission, including a variety of isotopes of different elements. These products are typically radioactive and play a significant role in nuclear reactor operation and nuclear waste management.
- Nuclear Fission: Articles that cover the process by which a heavy atomic nucleus splits into two smaller nuclei, releasing a significant amount of energy. This process is fundamental to the operation of nuclear reactors and the principles behind nuclear weapons.
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