Science topics: ChemistryIsotopes
Science topic

Isotopes - Science topic

Atomic species differing in mass number, but having the same atomic number. (Grant & Hackh's Chemical Dictionary, 5th ed)
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Publications related to Isotopes (10,000)
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The Bølling–Allerød (B-A), the terrestrial counterpart of Dansgaard–Oeschger 1, is the first abrupt northern hemisphere climate warming episode of the last deglaciation. Several hypotheses have been proposed to explain this event: all involve the strengthening of the Atlantic Meridional Overturning Circulation (AMOC) prior or during the Heinrich St...
Article
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Background Particles from non-exhaust emissions derived from traffic activities are a dominant cause of toxic metal pollution in urban environments. Recently, studies applying multiple isotope values using the Iso-source and positive matrix factorization (PMF) models have begun to be used as useful tools to evaluate the contribution of each polluti...
Article
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A well-known result in quasigroup theory says that an associative quasigroup is a group, i.e. in quasigroups, associativity forces the existence of an identity element. The converse is, of course, far from true, as there are many, many non-associative loops. However, a remarkable theorem due to David Mumford and C.P. Ramanujam says that any project...
Article
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Uranium and plutonium isotope concentrations as well as ²³⁶U/²³⁸U and ²⁴⁰Pu/²³⁹Pu atom ratios were measured by AMS in human lung samples from the early 1960s. The ²³⁶U concentrations as well as the ²³⁶U/²³⁸U atom ratios show a maximum in 1964, ²³⁹Pu and ²⁴⁰Pu concentrations are increasing continually from 1962 to 1965. ²³⁶U/²³⁸U atom ratios are low...
Experiment Findings
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Logi Corp R & D is developing a small proof of concept research reactor, as previously posted, able to contain a variety of plasmas and their nuclear reactions. Quark-gluon plasma is extremely difficult to contain, so a good starting place is to develop a prototype that can withstand a variety of exotic and under-researched plasmas and their fusio...
Article
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The assessment of an $$\alpha $$ α -particle optical model potential for nucleon–induced $$\alpha $$ α -emission within the $$A$$ A $$\sim $$ ∼ 60 mass-number range [Avrigeanu and Avrigeanu (Eur. Phys. J. A 57:54, 2021)] is completed by analysis of neutron–induced reactions on stable Ni isotopes. The same consistent set of nuclear–model input param...
Article
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p>The method of Neutron Resonance Capture Analysis (NRCA) is currently being developed at the Frank Laboratory of Neutron Physics. The Analysis determines the elemental and isotope compositions of objects non-destructively, which makes it suitable measurement tools for artefacts without sampling. NRCA is based on the registration of neutron resonan...
Article
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The quantification of a species’ trophic niche is important to understand the species ecology and its interactions with the ecosystem it resides in. Despite the high frequency of long-finned pilot whale (Globicephala melas edwardii) strandings on the Aotearoa New Zealand coast, their trophic niche remains poorly understood. To assess the isotopic n...
Article
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Nuclear level densities (NLDs) and γ-ray strength functions (GSFs) of Sn120,124 have been extracted with the Oslo method from proton-γ coincidences in the (p,p′γ) reaction. The functional forms of the GSFs and NLDs have been further constrained with the Shape method by studying primary γ-transitions to the ground and first excited states. The NLDs...
Article
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Studies of weak interaction in nuclei are important tools for testing different aspects of the fundamental symmetries of the Standard Model. Neutrinoless double beta decay offers an unique venue of investigating the possibility that neutrinos are Majorana fermions and that the lepton number conservation law is violated. Here, I use a shell model ap...
Article
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As was found in our previous works, when Nafion swells in water, polymer fibers unwind into the bulk of the surrounding liquid. This effect is controlled by the content of deuterium in water. Here, we present the results of studying the dynamics of methylene blue (MB) adsorption on the Nafion surface for MB solutions based on natural water (deuteri...
Preprint
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Natural materials usually consist of isotopic mixtures, for which different isotopic ratios can lead to distinct material properties such as thermal conductivity and nucleation process. However, the knowledge of isotopic interface remains largely unexplored mainly due to the challenges in isotopic identification and property measurement at an atomi...
Preprint
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To figure out the reason for the drawback of the SWIFT waveform and realize the high-resolution ion isolation on the miniaturized linear ion trap mass spectrometer, we studied the efficiency that ions can be excited under different excitation periods and amplitudes at different frequencies and compared the overlap rates of the effective excitation...
Preprint
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The spectroscopic hyperfine constants for all the alkali atoms are reported. For atoms from lithium to cesium, only the long lived atomic isotopes are examined. For francium, the measured data for nuclear ground states of all available isotopes are listed. All results obtained since the beginning of laser investigations are presented, while for pre...
Article
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Resumen: Los elementos químicos integran la base material de todo lo que existe, y son parte de diversas interaccio-nes no solo entre ellos y el entorno, sino de las que suceden al interior de cada uno. Sus propiedades particulares obe-decen a que sus átomos están agrupados en arreglos específicos, y al cambiar el número de protones, se da lugar a...
Article
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Soil liquefaction is one of the most detrimental forms of earthquake-induced ground failure that can result in catastrophic damage to engineering structures. For the seismic safety evaluation of foundations and high-rise structures, it is the most critical way to assess liquefaction resistance. In this paper, an array number of isotropically consol...
Preprint
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I have investigated the $N$-dependence of the charge radii $r_c$ across $N=126$ in the Pb isotopes and the surface densities of $^{208}$Pb using new Skyrme interactions that contain a density-dependent spin-orbit term, which I have named the Skyrme-ddso interactions. I have compared the results obtained using Skyrme-Hartree-Fock-Bogoliubov calculat...
Poster
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Supplementary information to the Poster "Foxes as proxy for human activities in the past: Isotopic evidence from Southwest Germany"
Preprint
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A 510 day long-term measurement of a 45.3 g platinum foil acting as the sample and high voltage contact in an ultra-low-background high purity germanium detector was performed at Laboratori Nazionali del Gran Sasso (Italy). The data was used for a detailed study of double beta decay modes in natural platinum isotopes. Limits are produced in the ran...
Article
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We report the Sr and Ba isotopic compositions of 18 presolar SiC grains of types Y (11) and Z (7), rare types commonly argued to have formed in lower-than-solar metallicity asymptotic giant branch (AGB) stars. We find that the Y and Z grains show higher 88 Sr/ 87 Sr and more variable 138 Ba/ 136 Ba ratios than mainstream (MS) grains. According to F...
Article
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In this paper we study the theory of knotoids and braidoids and the theory of pseudo knotoids and pseudo braidoids on the torus T. In particular, we introduce the notion of mixed knotoids in S 2 , that generalizes the notion of mixed links in S 3 , and we present an isotopy theorem for mixed knotoids. We then generalize the Kauffman bracket polynom...
Preprint
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We report the Sr and Ba isotopic compositions of 18 presolar SiC grains of types Y (11) and Z (7), rare types commonly argued to have formed in lower-than-solar metallicity asymptotic giant branch (AGB) stars. We find that the Y and Z grains show higher 88Sr/87Sr and more variable 138Ba/136Ba ratios than mainstream (MS) grains. According to FRANEC...
Article
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We study neutrinoless double-β decay in an effective field theory (EFT) for heavy nuclei, which are treated as a spherical core coupled to additional neutrons and/or protons. Since the low-energy constants of the EFT cannot be fitted to data for this unobserved decay, we follow an alternative strategy to constrain these through a correlation with d...
Article
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By using corks we construct diffeomorphic ribbon disks \(D\subset B^{4}\), which are not smoothly isotopic rel boundary to each other.
Conference Paper
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The paper presents the results of the analysis of 87Sr/86Sr isotope ratios for 21 individuals and 15 animals. All materials belong to the Bronze Age of the Southern Trans-Urals (5 archaeological sites). Three types of specimens were used (bone, dentin and tooth enamel). A total of 62 measurements were taken. Paired or triple analyzes of samples are...
Article
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En la anemia hemolítica autoinmune caliente, los eritrocitos pueden estar opsonizados por autoanticuerpos de los isótopos IgA e IgM. Esto induce traslocacion de los lípidos de la membrana eritrocitaria y la exposición de fosfatidilserina de la cara interna a la externa de la membrana, lo cual provoca la remoción de los eritrocitos de la circulación...
Article
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We define a suitably tame class of singular symplectic curves in 4-manifolds, namely those whose singularities are modeled on complex curve singularities. We study the corresponding symplectic isotopy problem, with a focus on rational curves with irreducible singularities (rational cuspidal curves) in the complex projective plane. We prove that eve...
Article
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Radium isotopes have been used to trace nutrient, carbon, and trace metal fluxes inputs from ocean margins. However, these approaches require a full accounting of radium sources to the coastal ocean including rivers. Here, we aim to quantify river radium inputs into the Arctic Ocean for the first time for ²²⁶Ra and to refine the estimates for ²²⁸Ra...
Article
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Elements with weak and blended spectral features in stellar spectra are challenging to measure and require specialized analysis methods to precisely measure their chemical abundances. In this work, we have created a catalog of approximately 120,000 giants with high signal-to-noise Apache Point Observatory Galactic Evolution Experiment (APOGEE) Data...
Preprint
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Neutrinoless double-beta (0$\nu\beta\beta$) decay is the most compelling approach to determine the Majorana nature of neutrino and measure effective Majorana neutrino mass. The LEGEND collaboration is aiming to look for neutrinoless double-beta decay of ${}^{76}$Ge with unprecedented sensitivity. If underground-sourced argon is not available, the c...
Article
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The glacial landscape of northern Brandenburg, especially the Eberswalde–Chorin area, is one of the most important study areas of Quaternary research in northern Germany, not only with respect to its research history, but especially with regard to new mapping, sedimentological logging, and dating results using up-to-date methodologies. These new re...
Article
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p>El uso de isótopos ha cobrado relevancia en ciencias gracias a la aparición de espectrómetros de masas cada vez más compactos y asequibles. Las aplicaciones de los análisis isotópicos se han convertido en una herramienta rutinaria en áreas como ciencias de la tierra, biología y ciencia forense. Por lo que el tema de los isótopos cobra relevancia...
Technical Report
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The usual radon detection mechanisms rely on the assumption that radon-222 is the only radon isotope present in our basement air, without taking into account the radon-220 isotope. The presence of the latter makes the usual algorithm produce results that output negative concentration and hence make no sense. In this paper, we present a modification...
Poster
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The Coralline Crag formation faunal assemblage presents conflicting fossil evidence of warm (Cardites squamulosa ampla) and subpolar (Arctica islandica) bivalve species, along with more eurythermal ones (Glycymeris obovata, Aequipecten opercularis). Paleo-thermometry based on the isotopic ratios of the shells can help determine more accurately the...
Article
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The nuclear electron capture reaction possesses a prominent position among other weak interaction processes occurring in explosive nucleosynthesis, especially at the late stages of evolution of massive stars. In this work, we perform exclusive calculations of absolute e−-capture cross sections using the proton–neutron (pn) quasi-particle random pha...
Preprint
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The finite distribution of the nuclear magnetic moment across the nucleus gives a contribution to the hyperfine structure known as the Bohr-Weisskopf (BW) effect. We have obtained an empirical value of -0.24(18)% for this effect in the ground and excited s states of atomic Cs-133. This value is found from historical muonic-atom measurements in comb...
Article
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The stellar electron capture on nuclei is an essential, semi-leptonic process that is especially significant in the central environment of core-collapse supernovae and in the explosive stellar nucleosynthesis. In this article, on the basis of the original (absolute) electron-capture cross-sections under laboratory conditions that we computed in our...
Article
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This report is the first describing a study quantitatively analysing aspects of oxide surface protonics in a dry H2 atmosphere. Elucidating surface protonics is important for electrochemical and catalytic applications. In this study, AC impedance spectroscopy was used to investigate surface conduction properties of porous CeO2 at low temperatures (...
Preprint
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Quasi-elastic neutron scattering (QENS) is a powerful technique to study protein dynamics. In general, QENS measurements are carried out in D2O solvent whereas functional studies of proteins are conducted in H2O solvent. Therefore, to link the QENS studies with the functional studies and then to understand the molecular basis of protein functions i...
Article
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The linking number is usually defined as an isotopy invariant of two non-intersecting closed curves in 3-dimensional space. However, the original definition in 1833 by Gauss in the form of a double integral makes sense for any open disjoint curves considered up to rigid motion. Hence the linking number can be studied as an isometry invariant of rig...
Preprint
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In this work we propose a new method to measure the evolution of the neutron skin thickness between different isotopes. We consider antiproton-nucleus interactions close to the production threshold of ${\Lambda}\overline{\Lambda}$ and ${\Sigma}\overline{\Lambda}$ pairs. At low energies, ${\Lambda}\overline{\Lambda}$ pairs are produced in p + p coll...
Article
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C metabolic flux analysis ( ¹³ C-MFA) has emerged as a forceful tool for quantifying in vivo metabolic pathway activity of different biological systems. This technology plays an important role in understanding intracellular metabolism and revealing patho-physiology mechanism. Recently, it has evolved into a method family with great diversity in exp...
Article
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One of the most important tools to investigate the chemical history of our Galaxy and our own Solar System is to measure the isotopic fractionation of chemical elements. This is the process that distributes the less abundant stable isotopes of an element in different molecules. The isotopic ratios are governed by two main processes: 1. chemical evo...
Preprint
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One of the most abundant man-made sources of low energy (few~MeVs) neutrinos, reactor neutrino, is not only useful for studying neutrino properties, but it is also used in practical applications. In this study, we investigate the practical use of reactor neutrino detectors for nuclear safeguard in Vietnam, specifically at the Dalat Nuclear Reactor,...
Preprint
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Besides the yield ratio of free spectator neutrons produced in ultracentral $^{96}$Zr+$^{96}$Zr to $^{96}$Ru+$^{96}$Ru collisions, we propose that the yield ratio $N_n/N_p$ of free spectator neutrons to protons in a single collision system at RHIC and LHC can be a more sensitive probe of the neutron-skin thickness $\Delta r_{\mathrm{np}}$ and the s...
Article
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The knowledge of isotopic abundances is important in galaxy evolution studies because isotopes provide diagnostics for the chemical enrichment in galaxies over time. While measurements of isotopes in large sample of stars would be ideal to determine the fossil record of the enrichment history, in practice this is hampered by the need of very high r...
Article
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Significant knowledge gaps in mercury (Hg) cycling challenge our ability to assess the effectiveness of the Minamata Convention on Mercury in reducing human and wildlife Hg exposure due to the complicated impacts of climate change. In this study, we comprehensively quantified the Hg spatial distribution and determined the Hg stable isotopes to unde...
Article
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The IUPAC–IUGS joint Task Group “Isotopes in Geosciences” (TGIG) has evaluated the published literature on the half-lives of six long-lived, geologically relevant radioactive nuclides. Where conflicting literature estimates are present, it is necessary to first identify any systematic bias in accordance with metrological traceability and to exclude...
Preprint
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Vibrational spectroscopy is a powerful tool for determining the local hydrogen-bonding environment. However, vibrational coupling present in H2O can make it difficult to relate vibrational spectra to a molecular description of the system. While numerous bulk studies have shed light on this phenomenon, the influence of both intra- and intermolecular...
Preprint
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Dansgaard-Oeschger (D-O) events, millennial-scale climate oscillations between stadial and interstadial conditions (of up to 10–15 °C in amplitude at high northern latitudes), occurred throughout the Marine Isotope Stage 3 (MIS3; 27.8–59.4 ka) period. The climate modelling community up to now has not been able to answer the question: Are our climat...
Preprint
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In this paper we ask if there is an interesting twist in mathematics of the Feynman propagator of the present day [1] formalism for the Dirac equation. The case studied is with only a potential function V . If there is no special integration order per step for e.g. dx(0) = dx1dx2dx3 and dp(0) = dp1dp2dp3, then a delta function occurs when c∆t ≈ 0 a...
Article
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The AMoRE collaboration is preparing for the AMoRE-II experiment that will probe neutrinoless double beta decay with 100 kg of ¹⁰⁰Mo isotope. The ¹⁰⁰Mo nuclide will be mainly in the form of lithium molybdate crystals that are instrumented with metallic magnetic calorimeters (MMC), which detect the phonon excitations produced by electrons from neutr...
Article
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As an important part of the northern Huaiyang tectonic belt, the Mesozoic Xiaotian basin hosts a series of gold and alunite deposits. However, the ages of these deposits remain unclear, constraining the further understanding of the genesis of these deposits. In this work, zircon LA–ICP-MS and alunite 39Ar/40Ar isotopic dating studies were carried o...
Article
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The reactive collision between Be atom and H2 molecule has received great interest both experimentally and theoretically due to its significant role in hydrogen storage, astrophysics, quantum chemistry and other fields, but the corresponding dynamics calculations have not been reported. Herein, a globally accurate ground-state BeH2 PES is represent...
Article
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The article presents the results of statistical analyzes of meteorological and atmospheric radon concentration measurements carried out in Krakow in the years 2004–2013. Based on the diurnal variability, an estimation of the height of the nocturnal boundary layer was performed and compared with the ERA5 data. The average concentration of radon in t...
Article
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The response of soybean to biological nitrogen fixation (BNF) varies due to factors such as plant variety, soil, and environmental conditions, which can compromise the N2 fixation capacity. The objective of this study was to evaluate additional inoculation with B. japonicum at different soybean growth stages as a strategy to improve N2 fixation. Th...