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Journal articles on the topic 'Isotopic abundance'

Author: Grafiati

Published: 2 June 2025

Last updated: 31 July 2025

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1

Burgess, Ray, Mitsuru Ebihara, and Hans Eggenkamp. "Developments in Halogen Abundance and Isotope Measurements." Elements 18, no. 1 (2022): 41–46. http://dx.doi.org/10.2138/gselements.18.1.41.

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The four stable halogens (F, Cl, Br, and I) are low-abundance elements that are widely distributed in nature. Two of the halogens, Cl and Br, each have two stable isotopes showing a range in natural isotope variation of up to a few parts per thousand. A variety of analytical techniques have been developed to determine the abundance and isotopic ratios of the halogens: these include in situ techniques for high spatial resolution studies and bulk determinations, and they have been applied to a range of materials, including whole rocks, minerals, glasses, and fluid inclusions. Here, we summarise

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2

Vanysek, V. "Isotopic Abundances in Comets." Symposium - International Astronomical Union 120 (1987): 461–67. http://dx.doi.org/10.1017/s0074180900154488.

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It is belived that the unprocessed material of the solar nebula may be preserved in comets. Thus the data concerning the chemical composition and the abundance of stable isotopes in these primitive bodies are of some importance in cosmological and cosmogonical context. Although the isotopic abundance in the small bodies of the Solar System are poorly known, owing to the forthcoming Halley fly-by missions, the discussion as whether or not the comets have preserved the cosmic isotopic ratio in their nuclei became more relevant. From this point of view expected data of the cosmologically and cosm

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3

Tea, Illa, Arnaud De Luca, Anne-Marie Schiphorst, et al. "Stable Isotope Abundance and Fractionation in Human Diseases." Metabolites 11, no. 6 (2021): 370. http://dx.doi.org/10.3390/metabo11060370.

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The natural abundance of heavy stable isotopes (13C, 15N, 18O, etc.) is now of considerable importance in many research fields, including human physiology. In fact, it varies between tissues and metabolites due to isotope effects in biological processes, that is, isotope discriminations between heavy and light isotopic forms during enzyme or transporter activity. The metabolic deregulation associated with many diseases leads to alterations in metabolic fluxes, resulting in changes in isotope abundance that can be identified easily with current isotope ratio technologies. In this review, we sum

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Meija, Juris. "Isotopic abundance challenge." Analytical and Bioanalytical Chemistry 391, no. 1 (2008): 1–2. http://dx.doi.org/10.1007/s00216-008-1981-4.

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5

Miljević, Nada, and Dušan Golobočanin. "Potential Use of Environmental Isotopes in Pollutant Migration Studies." Archives of Industrial Hygiene and Toxicology 58, no. 2 (2007): 251–62. http://dx.doi.org/10.2478/v10004-007-0015-5.

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Potential Use of Environmental Isotopes in Pollutant Migration StudiesThis article presents the use of natural abundance stable isotope (hydrogen, carbon, nitrogen, oxygen, chlorine) analysis data as a tool for providing important information about the origin of contaminants, the contribution of different sources to a multi-source plume, characterisation of their complex transport (rate and mechanisms) and for evaluating the success of contaminated site remediation. Isotopic signatures of contaminants are useful tracers of their sources, while isotopic fractionation can be used to quantitative

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6

Marti, Kurt, and K. J. Mathew. "Xenon in the Protoplanetary Disk (PPD), in Two Planets, and a Comet." Astrophysical Journal 940, no. 1 (2022): 14. http://dx.doi.org/10.3847/1538-4357/ac9904.

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Abstract Isotopic anomalies in several elements, as recently observed in meteorites, are generally interpreted to indicate nonequilibrium environments in the protoplanetary disk (PPD). Here we study reported Xe isotopic compositions on planets Earth and Mars, in a comet, and in meteorites for precursor discrepancies. Abundance variations of inferred presolar nano-diamonds, the carrier phase of the Xe-HL component, appear to be the primary source of nonuniformity of Xe precursors in the PPD, together with mechanisms of mass-dependent fractionation. While planet Mars kept a record of initial sol

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Kim, Seonho, Kwang Hyun Sung, and Kyujin Kwak. "Isotopic Compositions of Ruthenium Predicted from the NuGrid Project." Astrophysical Journal 924, no. 2 (2022): 88. http://dx.doi.org/10.3847/1538-4357/ac35e1.

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Abstract The isotopic compositions of ruthenium (Ru) are measured from presolar silicon carbide (SiC) grains. In a popular scenario, the presolar SiC grains formed in the outskirt of an asymptotic giant branch (AGB) star, left the star as a stellar wind, and joined the presolar molecular cloud from which the solar system formed. The Ru isotopes formed inside the star, moved to the stellar surface during the AGB phase, and were locked into the SiC grains. Following this scenario, we analyze the Nucleosynthesis Grid (NuGrid) data, which provide the abundances of the Ru isotopes in the stellar wi

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Collet, R., M. Asplund, and P. E. Nissen. "The Barium Isotopic Abundance in the Metal-Poor Star HD140283." Publications of the Astronomical Society of Australia 26, no. 3 (2009): 330–34. http://dx.doi.org/10.1071/as08057.

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AbstractWe derive the mixture of odd to even barium isotopes in the atmosphere of the metal-poor subgiant HD140283 from the analysis of the Ba ii transition at 4554 Å in a high-resolution high signal-to-noise spectrum of the star. The detailed shape of this spectral line depends on the relative contributions of odd and even isotopes via isotopic and hyperfine splitting. We measure the fractional abundance of odd Ba isotopes by modelling the formation of the Ba ii 4554-Å line profile with the use of both a classical 1D hydrostatic and a 3D hydrodynamical model atmosphere of HD140283. We interpr

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Coplen, Tyler B., John Karl Böhlke, P. De Bièvre, et al. "Isotope-abundance variations of selected elements (IUPAC Technical Report)." Pure and Applied Chemistry 74, no. 10 (2002): 1987–2017. http://dx.doi.org/10.1351/pac200274101987.

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Documented variations in the isotopic compositions of some chemical elements are responsible for expanded uncertainties in the standard atomic weights published by the Commission on Atomic Weights and Isotopic Abundances of the International Union of Pure and Applied Chemistry. This report summarizes reported variations in the isotopic compositions of 20 elements that are due to physical and chemical fractionation processes (not due to radioactive decay) and their effects on the standard atomic-weight uncertainties. For 11 of those elements (hydrogen, lithium, boron, carbon, nitrogen, oxygen,

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Coplen, Tyler B., and Yesha Shrestha. "Isotope-abundance variations and atomic weights of selected elements: 2016 (IUPAC Technical Report)." Pure and Applied Chemistry 88, no. 12 (2016): 1203–24. http://dx.doi.org/10.1515/pac-2016-0302.

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AbstractThere are 63 chemical elements that have two or more isotopes that are used to determine their standard atomic weights. The isotopic abundances and atomic weights of these elements can vary in normal materials due to physical and chemical fractionation processes (not due to radioactive decay). These variations are well known for 12 elements (hydrogen, lithium, boron, carbon, nitrogen, oxygen, magnesium, silicon, sulfur, chlorine, bromine, and thallium), and the standard atomic weight of each of these elements is given by IUPAC as an interval with lower and upper bounds. Graphical plots

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11

Vanysek, V. "Isotopic Ratios in Comets." International Astronomical Union Colloquium 116, no. 2 (1991): 879–95. http://dx.doi.org/10.1017/s0252921100012756.

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Abstract.The isotopic abundances depend on the universal evolution of elements and on the individual history of particular objects. Since it is believed that unprocessed material of the solar nebula is preserved in comets, the data concerning the abundance of stable isotopes in these primitive bodies are of some importance in the cosmological context. The present status of this problem is reviewed. The reliability of results for nuclear species with cosmological and cosmogonical implications, such as D/H, C 12/13, N 14/15, O 16/18, and Mg 24/25/26, is discussed. Significant variation is found

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Badea, Silviu-Laurentiu, Violeta-Carolina Niculescu, and Andreea-Maria Iordache. "New Trends in Separation Techniques of Lithium Isotopes: A Review of Chemical Separation Methods." Materials 16, no. 10 (2023): 3817. http://dx.doi.org/10.3390/ma16103817.

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In terms of isotopic technologies, it is essential to be able to produce materials with an enriched isotopic abundance (i.e., a compound isotopic labelled with 2H, 13C, 6Li, 18O or 37Cl), which is one that differs from natural abundance. The isotopic-labelled compounds can be used to study different natural processes (like compounds labelled with 2H, 13C, or 18O), or they can be used to produce other isotopes as in the case of 6Li, which can be used to produce 3H, or to produce LiH that acts like a protection shield against fast neutrons. At the same time, 7Li isotope can be used as a pH contr

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Chang, Tsing-Lien, Qiu-Yu Qian, Mo-Tian Zhao, and Jun Wang. "The isotopic abundance of antimony." International Journal of Mass Spectrometry and Ion Processes 123, no. 1 (1993): 77–82. http://dx.doi.org/10.1016/0168-1176(93)87056-x.

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14

Meija, Juris. "Solution to isotopic abundance challenge." Analytical and Bioanalytical Chemistry 392, no. 1-2 (2008): 17–18. http://dx.doi.org/10.1007/s00216-008-2241-3.

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15

Chaud, Saula Goulart, Admar Costa de Oliveira, and Paulo César Ocheuze Trivelin. "Nitrogen 15 abundance in protein fractions of beans fertilized with (15NH4)2SO4." Scientia Agricola 59, no. 4 (2002): 777–80. http://dx.doi.org/10.1590/s0103-90162002000400023.

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Studies evaluating the protein nutritive value of beans labelled with 15N, ussing nitrogen balance and the quantitation of faecal and urinary endogenous nitrogen, determined by isotopic dilution, have been extensively used. The objective of this research was to verify if the isotopic labelling of raw, freeze dried beans (Phaseolus vulgaris L., cultivar Piratã 1) with 1.394 atoms%15N, resulted in the same abundance of the whole flour and of the protein fractions extracted from the beans with 0.5 mol L-1 NaCl. The isotopic abundance found in the whole bean flour, in the protein extract, in the g

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16

Trivedi, Mahendra Kumar, Alice Branton, Dahryn Trivedi, Gopal Nayak, Parthasarathi Panda, and Snehasis Jana. "Isotopic Abundance Ratio Analysis of 1,2,3-Trimethoxybenzene (TMB) After Biofield Energy Treatment (The Trivedi Effect®) Using Gas Chromatography-Mass Spectrometry." American Journal of Applied Chemistry 4, no. 4 (2016): 132–40. https://doi.org/10.11648/j.ajac.20160404.13.

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1,2,3-Trimethoxybenzene (TMB) is one of the most versatile chemical used for the synthesis of several pharmaceuticals, dyes, polymers, organic compounds, etc. The stable isotope ratio analysis has increased attention day-by-days in several fields such as agricultural, food authenticity, biochemistry, medical research, etc. The current study was aimed to evaluate the effect of the biofield energy treatment on the isotopic abundance ratios of 13C/12C or 2H/1H or 17O/16O (PM+1/PM) and 18O/16O (PM+2/PM) in TMB using Gas chromatography - mass spectrometry (GC-MS) technique. TMB was divided into two

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Trivedi, Mahendra Kumar, Alice Branton, Dahryn Trivedi, Gopal Nayak, Parthasarathi Panda, and Snehasis Jana. "Isotopic Abundance Ratio Analysis of 1,2,3-Trimethoxybenzene (TMB) After Biofield Energy Treatment (The Trivedi Effect®) Using Gas Chromatography-Mass Spectrometry." American Journal of Applied Chemistry 4, no. 4 (2016): 132–40. https://doi.org/10.5281/zenodo.196902.

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1,2,3-Trimethoxybenzene (TMB) is one of the most versatile chemical used for the synthesis of several pharmaceuticals, dyes, polymers, organic compounds, etc. The stable isotope ratio analysis has increased attention day-by-days in several fields such as agricultural, food authenticity, biochemistry, medical research, etc. The current study was aimed to evaluate the effect of the biofield energy treatment on the isotopic abundance ratios of 13C/12C or 2H/1H or 17O/16O (PM+1/PM) and 18O/16O (PM+2/PM) in TMB using Gas chromatography - mass spectrometry (GC-MS) technique. TMB was divided into two

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18

Pavlenko, Yakiv V., Sergei N. Yurchenko, and Jonathan Tennyson. "Analysis of the first overtone bands of isotopologues of CO and SiO in stellar spectra." Astronomy & Astrophysics 633 (January 2020): A52. http://dx.doi.org/10.1051/0004-6361/201936811.

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Context. This study is based on models of the first overtone (Δv = 2) bands of the monosubstituted isotopologues of CO at 2.3 μm in the spectrum of Arcturus (K2 III) and of the monosubstituted isotopologues of SiO at 4 μm in the spectrum of the red giant HD 196610 (M6 III). Aims. We aim to investigate problems involving the computation of the first overtone bands of isotopologues of CO and SiO in the spectra of late-type stars and to determine isotopic abundances. Methods. We used fits of theoretical synthetic spectra to the observed stellar molecular bands of CO and SiO for determining the ab

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19

Tcherkez, Guillaume. "Natural 15N/14N isotope composition in C3 leaves: are enzymatic isotope effects informative for predicting the 15N-abundance in key metabolites?" Functional Plant Biology 38, no. 1 (2011): 1. http://dx.doi.org/10.1071/fp10091.

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Although nitrogen isotopes are viewed as important tools for understanding plant N acquisition and allocation, the current interpretation of natural 15N-abundances (δ15N values) is often impaired by substantial variability among individuals or between species. Such variability is likely to stem from the fact that 15N-abundance of assimilated N is not preserved during N metabolism and redistribution within the plant; that is, 14N/15N isotope effects associated with N metabolic reactions are certainly responsible for isotopic shifts between organic-N (amino acids) and absorbed inorganic N (nitra

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20

Lewicka-Szczebak, Dominika, Maciej Piotr Lewicki, and Reinhard Well. "N<sub>2</sub>O isotope approaches for source partitioning of N<sub>2</sub>O production and estimation of N<sub>2</sub>O reduction – validation with the <sup>15</sup>N gas-flux method in laboratory and field studies." Biogeosciences 17, no. 22 (2020): 5513–37. http://dx.doi.org/10.5194/bg-17-5513-2020.

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Abstract. The approaches based on natural abundance N2O stable isotopes are often applied for the estimation of mixing proportions between various N2O-producing pathways as well as for estimation of the extent of N2O reduction to N2. But such applications are associated with numerous uncertainties; hence, their limited accuracy needs to be considered. Here we present the first systematic validation of these methods for laboratory and field studies by applying the 15N gas-flux method as the reference approach. Besides applying dual-isotope plots for interpretation of N2O isotopic data, for the

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21

Marti, Kurt, Mario Fischer-Gödde, and Carina Proksche. "Meteoritic Molybdenum and Ruthenium Isotopic Abundances Document Nucleosynthetic p-process Components." Astrophysical Journal 956, no. 1 (2023): 7. http://dx.doi.org/10.3847/1538-4357/acee81.

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Abstract Anomalies in isotopic abundances of Mo and Ru in solar system matter were found to document variable contributions of the nucleosynthetic s-process component. We report isotopic relations of ϵ 92Mo versus ϵ 100Ru in meteorites from chondritic parent bodies, iron meteorites, and achondrites that reveal deviations from expected s-process abundance variations. We show that two p-process isotopes 92Mo and 94Mo require the presence of distinct p-process components in meteoritic materials. The nucleosynthetic origin of abundant magic (N = 50) p-process nuclides, covering the mass range of Z

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22

Nosowitz, Jonathon, Martin A. Cordiner, Conor A. Nixon, et al. "Improved Carbon and Nitrogen Isotopic Ratios for CH₃CN in Titan’s Atmosphere Using ALMA." Planetary Science Journal 6, no. 5 (2025): 107. https://doi.org/10.3847/psj/adc390.

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Abstract Titan, Saturn’s largest satellite, maintains an atmosphere composed primarily of nitrogen (N2) and methane (CH4) that leads to complex organic chemistry. Some of the nitriles (CN-bearing organics) on Titan are known to have substantially enhanced 15N abundances compared to Earth and Titan’s dominant nitrogen (N2) reservoir. The 14N/15N isotopic ratio in Titan’s nitriles can provide better constraints on the synthesis of nitrogen-bearing organics in planetary atmospheres as well as insights into the origin of Titan’s large nitrogen abundance. Using high signal-to-noise ratio (>13),

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Boyce, Jeremy W., Allan H. Treiman, Yunbin Guan, et al. "The chlorine isotope fingerprint of the lunar magma ocean." Science Advances 1, no. 8 (2015): e1500380. http://dx.doi.org/10.1126/sciadv.1500380.

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The Moon contains chlorine that is isotopically unlike that of any other body yet studied in the Solar System, an observation that has been interpreted to support traditional models of the formation of a nominally hydrogen-free (“dry”) Moon. We have analyzed abundances and isotopic compositions of Cl and H in lunar mare basalts, and find little evidence that anhydrous lava outgassing was important in generating chlorine isotope anomalies, because 37Cl/35Cl ratios are not related to Cl abundance, H abundance, or D/H ratios in a manner consistent with the lava-outgassing hypothesis. Instead, 37C

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Fenner, Y., B. K. Gibson, H. c. Lee, et al. "The Chemical Evolution of Magnesium Isotopic Abundances in the Solar Neighbourhood." Publications of the Astronomical Society of Australia 20, no. 4 (2003): 340–44. http://dx.doi.org/10.1071/as03042.

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AbstractThe abundance of the neutron-rich magnesium isotopes observed in metal-poor stars is explained quantitatively with a chemical evolution model of the local Galaxy that considers — for the first time — the metallicity-dependent contribution from intermediate mass stars. Previous models that simulate the variation of Mg isotopic ratios with metallicity in the solar neighbourhood have attributed the production of 25Mg and 26Mg exclusively to hydrostatic burning in massive stars. These models match the data well for [Fe/H] > –1.0 but severely underestimate 25,26Mg/24Mg at lower metallici

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Bocherens, Hervé, Daniel Billiou, Marylène Patou-Mathis, Dominique Bonjean, Marcel Otte, and André Mariotti. "Paleobiological Implications of the Isotopic Signatures (13C,15N) of Fossil Mammal Collagen in Scladina Cave (Sclayn, Belgium)." Quaternary Research 48, no. 3 (1997): 370–80. http://dx.doi.org/10.1006/qres.1997.1927.

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An isotopic investigation of upper Pleistocene mammal bones and teeth from Scladina cave (Sclayn, Belgium) demonstrated the very good quality of collagen preservation. A preliminary screening of the samples used the amount of nitrogen in whole bone and dentine in order to estimate the preserved amount of collagen before starting the extraction process. The isotopic abundances of fossil specimens from still-extant species are consistent with their trophic position. Moreover, the15N isotopic abundance is higher in dentine than in bone in bears and hyenas, a phenomenon already observed in modern

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Araus, José Luis, Llorenç Cabrera-Bosquet, María Dolores Serret, Jordi Bort та María Teresa Nieto-Taladriz. "Comparative performance of δ13C, δ18O and δ15N for phenotyping durum wheat adaptation to a dryland environment". Functional Plant Biology 40, № 6 (2013): 595. http://dx.doi.org/10.1071/fp12254.

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Grain yield and the natural abundance of the stable isotope compositions of carbon (δ13C), oxygen (δ18O) and nitrogen (δ15N) of mature kernels were measured during 3 consecutive years in 10 durum wheat genotypes (five landraces and five modern cultivars) subjected to different water and N availabilities in a Mediterranean location and encompassing a total of 12 trials. Water limitation was the main environmental factor affecting yield, δ13C and δ18O, whereas N fertilisation had a major effect on δ15N. The genotypic effect was significant for yield, yield components, δ13C, δ18O and δ15N. Landra

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Diao, Haoyu, Philipp Schuler, Gregory R. Goldsmith, Rolf T. W. Siegwolf, Matthias Saurer, and Marco M. Lehmann. "Technical note: On uncertainties in plant water isotopic composition following extraction by cryogenic vacuum distillation." Hydrology and Earth System Sciences 26, no. 22 (2022): 5835–47. http://dx.doi.org/10.5194/hess-26-5835-2022.

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Abstract. Recent studies have challenged the interpretation of plant water isotopes obtained through cryogenic vacuum distillation (CVD) based on observations of a large 2H fractionation. These studies have hypothesized the existence of an H-atom exchange between water and organic tissue during CVD extraction with the magnitude of H exchange related to relative water content of the sample; however, clear evidence is lacking. Here, we systematically tested the uncertainties in the isotopic composition of CVD-extracted water by conducting a series of incubation and rehydration experiments using

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Brand, Willi A., Tyler B. Coplen, Jochen Vogl, Martin Rosner, and Thomas Prohaska. "Assessment of international reference materials for isotope-ratio analysis (IUPAC Technical Report)." Pure and Applied Chemistry 86, no. 3 (2014): 425–67. http://dx.doi.org/10.1515/pac-2013-1023.

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AbstractSince the early 1950s, the number of international measurement standards for anchoring stable isotope delta scales has mushroomed from 3 to more than 30, expanding to more than 25 chemical elements. With the development of new instrumentation, along with new and improved measurement procedures for studying naturally occurring isotopic abundance variations in natural and technical samples, the number of internationally distributed, secondary isotopic reference materials with a specified delta value has blossomed in the last six decades to more than 150 materials. More than half of these

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Farouqi, K., K. L. Kratz, and B. Pfeiffer. "Co-Production of Light p-, s- and r-Process Isotopes in the High-Entropy Wind of Type II Supernovae." Publications of the Astronomical Society of Australia 26, no. 3 (2009): 194–202. http://dx.doi.org/10.1071/as08075.

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AbstractWe have performed large-scale nucleosynthesis calculations within the high-entropy-wind (HEW) scenario of Type II supernovae. The primary aim was to constrain the conditions for the production of the classical ‘p-only’ isotopes of the light trans-Fe elements. We find, however, that for electron fractions in the range 0.458 ≤ Ye ≤ 0.478, sizeable abundances of p-, s- and r-process nuclei between 64Zn and 98Ru are coproduced in the HEW at low entropies (S ≤ 100) by a primary charged-particle process after an α-rich freezeout. With the above Ye–S correlation, most of the predicted isotopi

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Coria, David R., Neda Hejazi, Ian J. M. Crossfield, and Maleah Rhem. "The Wanderer: Charting WASP-77A b’s Formation and Migration Using a System-wide Inventory of Carbon and Oxygen Abundances." Astrophysical Journal 974, no. 2 (2024): 151. http://dx.doi.org/10.3847/1538-4357/ad7020.

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Abstract The elemental and isotopic abundances of volatiles like carbon, oxygen, and nitrogen may trace a planet’s formation location relative to H2O, CO2, CO, NH3, and N2 “snowlines,” or the distance from the star at which these volatile elements sublimate. By comparing the C/O and 12C/13C ratios measured in giant exoplanet atmospheres to complementary measurements of their host stars, we can determine whether the planet inherited stellar abundances from formation inside the volatile snowlines, or nonstellar C/O and 13C enrichment characteristic of formation beyond the snowlines. To date, the

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Trivedi, Mahendra Kumar, Alice Branton, Dahryn Trivedi, Gopal Nayak, Gunin Saikia, and Snehasis Jana. "Evaluation of Isotopic Abundance Ratio in Naphthalene Derivatives After Biofield Energy Treatment Using Gas Chromatography-Mass Spectrometry." American Journal of Applied Chemistry 3, no. 6 (2015): 194–200. https://doi.org/10.5281/zenodo.50620.

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Naphthalene and 2-naphthol are two naphthalene derivatives, which play important roles in the chemical and pharmaceutical industries. The aim of this study was to evaluate the impact of biofield energy treatment on the isotopic abundance of 13C/12C or 2H/1H and 18O/16O in naphthalene and 2-naphthol using gas chromatography-mass spectrometry (GC-MS). Naphthalene and 2-naphthol samples were divided into two parts: control and treated. The control group remained as untreated, while the treated group was subjected to Mr. Trivedi’s biofield energy treatment. The treated samples were subdivide

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Trivedi, Mahendra Kumar, Alice Branton, Dahryn Trivedi, Gopal Nayak, Parthasarathi Panda, and Snehasis Jana. "Determination of Isotopic Abundance of 13C/12C or 2H/1H and 18O/16O in Biofield Energy Treated 1-Chloro-3-Nitrobenzene (3-CNB) Using Gas Chromatography-Mass Spectrometry." Science Journal of Analytical Chemistry 4, no. 4 (2016): 42–51. https://doi.org/10.11648/j.sjac.20160404.11.

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1-Chloro-3-nitrobenzene (3-CNB) is an aromatic halo-amine compound used as chemical intermediate for the production of several fine chemicals like pharmaceuticals, dyes, agricultural chemicals, etc. The stable isotope ratio analysis has drawn attention in numerous fields such as agricultural, food authenticity, biochemistry, etc. The objective of the current research was to investigate the impact of the biofield energy treatment on the isotopic abundance ratios of PM+1/PM, PM+2/PM and PM+3/PM in 3-CNB using gas chromatography - mass spectrometry (GC-MS). The sample, 3-CNB was divided into two

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Trivedi, Mahendra Kumar, Alice Branton, Dahryn Trivedi, Gopal Nayak, Parthasarathi Panda, and Snehasis Jana. "Determination of Isotopic Abundance of 13C/12C or 2H/1H and 18O/16O in Biofield Energy Treated 1-Chloro-3-Nitrobenzene (3-CNB) Using Gas Chromatography-Mass Spectrometry." Science Journal of Analytical Chemistry 4, no. 4 (2016): 42–51. https://doi.org/10.5281/zenodo.196927.

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1-Chloro-3-nitrobenzene (3-CNB) is an aromatic halo-amine compound used as chemical intermediate for the production of several fine chemicals like pharmaceuticals, dyes, agricultural chemicals, etc. The stable isotope ratio analysis has drawn attention in numerous fields such as agricultural, food authenticity, biochemistry, etc. The objective of the current research was to investigate the impact of the biofield energy treatment on the isotopic abundance ratios of PM+1/PM, PM+2/PM and PM+3/PM in 3-CNB using gas chromatography - mass spectrometry (GC-MS). The sample, 3-CNB was divided into two

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Rossete, Alexssandra Luiza Rodrigues Molina, Josiane Meire Toloti Carneiro, Carlos Roberto Sant Ana Filho, and José Albertino Bendassolli. "Isotope determination of sulfur by mass spectrometry in soil samples." Revista Brasileira de Ciência do Solo 36, no. 6 (2012): 1787–93. http://dx.doi.org/10.1590/s0100-06832012000600012.

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Sulphur plays an essential role in plants and is one of the main nutrients in several metabolic processes. It has four stable isotopes (32S, 33S, 34S, and 36S) with a natural abundance of 95.00, 0.76, 4.22, and 0.014 in atom %, respectively. A method for isotopic determination of S by isotope-ratio mass spectrometry (IRMS) in soil samples is proposed. The procedure involves the oxidation of organic S to sulphate (S-SO4(2-)), which was determined by dry combustion with alkaline oxidizing agents. The total S-SO4(2-) concentration was determined by turbidimetry and the results showed that the con

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Trivedi, Mahendra Kumar, Alice Branton, Dahryn Trivedi, Gopal Nayak, Kalyan Kumar Sethi, and Snehasis Jana. "Gas Chromatography-Mass Spectrometry Based Isotopic Abundance Ratio Analysis of Biofield Energy Treated Methyl-2-napthylether (Nerolin)." American Journal of Physical Chemistry 5, no. 4 (2016): 80–86. https://doi.org/10.11648/j.ajpc.20160504.11.

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Methyl-2-napthylether (nerolin) is an organic compound and has the applications in pharmaceutical, and perfume industry. The stable isotope ratio analysis is increasing importance in various field of scientific research. The objective of the current study was to evaluate the effect of the biofield energy treatment on the isotopic abundance ratios of PM+1/PM (2H/1H or 13C/12C or 17O/16O) and PM+2/PM (18O/16O) in nerolin using the gas chromatography-mass spectrometry (GC-MS). The compound nerolin was divided into two parts - one part was control sample (untreated), and another part was considere

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Trivedi, Mahendra Kumar, Alice Branton, Dahryn Trivedi, Gopal Nayak, Kalyan Kumar Sethi, and Snehasis Jana. "Gas Chromatography-Mass Spectrometry Based Isotopic Abundance Ratio Analysis of Biofield Energy Treated Methyl-2-napthylether (Nerolin)." American Journal of Physical Chemistry 5, no. 4 (2016): 80–86. https://doi.org/10.5281/zenodo.196912.

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Methyl-2-napthylether (nerolin) is an organic compound and has the applications in pharmaceutical, and perfume industry. The stable isotope ratio analysis is increasing importance in various field of scientific research. The objective of the current study was to evaluate the effect of the biofield energy treatment on the isotopic abundance ratios of PM+1/PM (2H/1H or 13C/12C or 17O/16O) and PM+2/PM (18O/16O) in nerolin using the gas chromatography-mass spectrometry (GC-MS). The compound nerolin was divided into two parts - one part was control sample (untreated), and another part was considere

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Madej, Adam, Ewa Forma, Michał Golberg, et al. "13C Natural Isotope Abundance in Urothelium as a New Marker in the Follow-Up of Patients with Bladder Cancer." Cancers 14, no. 10 (2022): 2423. http://dx.doi.org/10.3390/cancers14102423.

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Bladder cancer (BC) is the most common urological malignancy and has a high incidence of recurrence. BC cells alter their nutrient uptake and metabolic pathways in order to continue the production of sufficient levels of ATP and metabolic intermediates for proliferation and survival. Changes in metabolic pathways regarding the rate of the enzymatic reaction and transport lead to differences in the content of natural isotopes (13C, 15N, 34S) between normal and cancerous tissues. The assessment of the stable isotopes of carbon, nitrogen, and sulfur in normal urothelium and bladder cancer samples

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Trivedi, Mahendra Kumar, Alice Branton, Dahryn Trivedi, Gopal Nayak, Gunin Saikia, and Snehasis Jana. "Evaluation of Isotopic Abundance Ratio in Naphthalene Derivatives After Biofield Energy Treatment Using Gas Chromatography-Mass Spectrometry." American Journal of Applied Chemistry 3, no. 6 (2015): 194–200. https://doi.org/10.5281/zenodo.193858.

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Naphthalene and 2-naphthol are two naphthalene derivatives, which play important roles in the chemical and pharmaceutical industries. The aim of this study was to evaluate the impact of biofield energy treatment on the isotopic abundance of 13C/12C or 2H/1H and 18O/16O in naphthalene and 2-naphthol using gas chromatography-mass spectrometry (GC-MS). Naphthalene and 2-naphthol samples were divided into two parts: control and treated. The control group remained as untreated, while the treated group was subjected to Mr. Trivedi’s biofield energy treatment. The treated samples

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Chen, Ke, Bai Song, Navaneetha K. Ravichandran, et al. "Ultrahigh thermal conductivity in isotope-enriched cubic boron nitride." Science 367, no. 6477 (2020): 555–59. http://dx.doi.org/10.1126/science.aaz6149.

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Materials with high thermal conductivity (κ) are of technological importance and fundamental interest. We grew cubic boron nitride (cBN) crystals with controlled abundance of boron isotopes and measured κ greater than 1600 watts per meter-kelvin at room temperature in samples with enriched 10B or 11B. In comparison, we found that the isotope enhancement of κ is considerably lower for boron phosphide and boron arsenide as the identical isotopic mass disorder becomes increasingly invisible to phonons. The ultrahigh κ in conjunction with its wide bandgap (6.2 electron volts) makes cBN a promising

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Coria, David R., Ian J. M. Crossfield, Joshua Lothringer, Becky Flores, Nikos Prantzos, and Richard Freedman. "The Missing Link: Testing Galactic Chemical Evolution Models with the First Multi-isotopic Abundances in Solar Twin Stars." Astrophysical Journal 954, no. 2 (2023): 121. http://dx.doi.org/10.3847/1538-4357/acea5f.

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Abstract We present the first isotopic abundances of both 13CO and C18O in solar twin stars and test the results against several galactic chemical evolution (GCE) models with different nucleosynthesis prescriptions. First, we compare M-band spectra from IRTF/iSHELL to synthetic spectra generated from custom solar atmosphere models using the PHOENIX atmosphere code. Next, we compare our calculated abundances to GCE models that consider isotopic yields from massive stars, asymptotic giant branch stars, and fast-rotating stars. The 12C/13C ratios determined for this sample of solar twins are cons

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Ukozehasi, Celestin, and Howard Griffiths. "An isotopic proxy for nitrogen redistribution from Alnus acuminata to wheat intercrop." Experimental Agriculture 57, no. 5-6 (2021): 316–23. http://dx.doi.org/10.1017/s0014479721000284.

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SummaryDirect belowground nitrogen (N) transfer has often been reported where plants with contrasting nutrients acquisition strategies (N2-fixing and non-fixing) co-occur, and there is still a gap in the knowledge of the extent of this transfer in the top soil under the field conditions. However, assessment under field conditions is challenging. We hypothesized a practical application of the analysis of natural abundance of δ15N supplemented with an isotopic mixing model ‘IsoSource’ to understand the relative direct contribution of N2-fixing Alnus acuminata to wheat intercrop (non-fixing) N is

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Trivedi, Mahendra Kumar, Alice Branton, Dahryn Trivedi, Gopal Nayak, Parthasarathi Panda, and Snehasis Jana. "Mass Spectrometric Analysis of Isotopic Abundance Ratio in Biofield Energy Treated Thymol." World Journal of Applied Chemistry 1, no. 1 (2016): 001–8. https://doi.org/10.11648/j.wjac.20160101.11.

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Thymol is a natural monoterpenoid phenol possessing various pharmacological activities such as antimicrobial, antioxidant, etc. The stable isotope ratio analysis has drawn attention in numerous fields such as agricultural, food authenticity, biochemistry, metabolism, medical research, etc. An investigation of the effect of the biofield energy treatment (The Trivedi Effect®) on the isotopic abundance ratios of PM+1/PM and PM+2/PM in thymol using gas chromatography - mass spectrometry was attempted in this study. The sample, thymol was divided into two parts - one part was denoted as control

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Trivedi, Mahendra Kumar, Alice Branton, Dahryn Trivedi, Gopal Nayak, Parthasarathi Panda, and Snehasis Jana. "Mass Spectrometric Analysis of Isotopic Abundance Ratio in Biofield Energy Treated Thymol." World Journal of Applied Chemistry 1, no. 1 (2016): 001–8. https://doi.org/10.5281/zenodo.196892.

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Abstract:

Thymol is a natural monoterpenoid phenol possessing various pharmacological activities such as antimicrobial, antioxidant, etc. The stable isotope ratio analysis has drawn attention in numerous fields such as agricultural, food authenticity, biochemistry, metabolism, medical research, etc. An investigation of the effect of the biofield energy treatment (The Trivedi Effect®) on the isotopic abundance ratios of PM+1/PM and PM+2/PM in thymol using gas chromatography - mass spectrometry was attempted in this study. The sample, thymol was divided into two parts - one part was denoted as control

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Harutyunyan, G., M. Steffen, A. Mott, et al. "3D non-LTE corrections for Li abundance and 6Li/7Li isotopic ratio in solar-type stars." Astronomy & Astrophysics 618 (October 2018): A16. http://dx.doi.org/10.1051/0004-6361/201832852.

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Context. Convective motions in solar-type stellar atmospheres induce Doppler shifts that affect the strengths and shapes of spectral absorption lines and create slightly asymmetric line profiles. One-dimensional (1D) local thermodynamic equilibrium (LTE) studies of elemental abundances are not able to reproduce this phenomenon, which becomes particularly important when modeling the impact of isotopic fine structure, like the subtle depression created by the 6Li isotope on the red wing of the Li I resonance doublet line. Aims. The purpose of this work is to provide corrections for the lithium a

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Yong, David, David L. Lambert, and Inese I. Ivans. "Magnesium Isotopic Abundance Ratios in Cool Stars." Astrophysical Journal 599, no. 2 (2003): 1357–71. http://dx.doi.org/10.1086/379369.

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Mandt, K. E., O. Mousis, and S. Treat. "Determining the origin of the building blocks of the Ice Giants based on analogue measurements from comets." Monthly Notices of the Royal Astronomical Society 491, no. 1 (2019): 488–94. http://dx.doi.org/10.1093/mnras/stz3061.

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ABSTRACT The abundances of the heavy elements and isotopic ratios in the present atmospheres of the giant planets can be used to trace the composition of volatiles that were present in the icy solid material that contributed to their formation. The first definitive measurements of noble gas abundances and isotope ratios at comet 67P/Churyumov–Gerasimenko (67P/C–G) were recently published by Marty et al. (2017) and Rubin et al. (2018, 2019). The implications of these abundances for the formation conditions of the 67P/C–G building blocks were then evaluated by Mousis et al. (2018a). We add here

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Pandey, Kanishk, and Christopher West. "A partial isotopic decomposition for the sculptor dSph." Monthly Notices of the Royal Astronomical Society, September 23, 2022. http://dx.doi.org/10.1093/mnras/stac2688.

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Abstract All stellar evolution models require an initial isotopic abundance set as input, but these abundances are well known only for the Sun. Yet, input compositions can be estimated by scaling solar abundances using a previously constructed isotopic history model based on astrophysical processes in the Milky Way (MW). This method, however, may not work for obtaining inputs for compositions that have distinct chemical histories from the MW. We thus present a partial isotopic history model for the Sculptor dwarf spheroidal galaxy based on astrophysical processes, which can be used to estimate

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Farha, Aliparambil AbdulGaffur, Drisya Karinkuzhi, and Sophie van Eck. "The Eu Isotopic Ratios in CEMP Stars." Bulletin de la Société Royale des Sciences de Liège, 2024, 430–36. http://dx.doi.org/10.25518/0037-9565.11735.

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Understanding the chemical evolution of galaxies requires accurate abundances of chemical elements in various stellar populations, which are then compared with theoretical predictions to probe their nucleosynthetic origin. However, most of the elements have several stable isotopes which are produced by different nucleosynthetic reactions, thus making multiple contributors to their overall abundance. The situation will be more complex in the case of heavy elements produced by different neutron capture processes. Hence, the abundances at the isotopic levels are more important to constrain the co

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Lu, Xiaoyong, and Lide Wang. "Numerical studies on the isotopic selective photoionization of ytterbium in a three-step ionization scheme." Chinese Physics B, October 19, 2022. http://dx.doi.org/10.1088/1674-1056/ac9b2f.

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Abstract Numerical studies of selective photoionization of ytterbium isotope have been carried out based on a three-step photoionization scheme, 4f 146s 2 1S0 (0 cm-1) → 4f 146s6p 3P1 (17992.008 cm-1) → (4f 136s 26p) (7/2, 3/2)2 (35196.98 cm-1) → auto-ionization state (52353 cm-1) → Yb+, by the density matrix theory with the consideration of atomic hyperfine structures and magnetic sublevels. To examine the physical model, the numerical isotopic abundances of ytterbium are compared with those of mass spectroscopy experiments and good agreements are acquired. The excitation and ionization proce

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Turschak, Benjamin A., Charles R. Bronte, Sergiusz J. Czesny, et al. "Temporal Variation in the Niche Partitioning of Lake Michigan Salmonines as it Relates to Alewife Abundance and Size Structure." Canadian Journal of Fisheries and Aquatic Sciences, August 27, 2021. http://dx.doi.org/10.1139/cjfas-2021-0027.

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Stable isotope analyses offer a useful means for quantifying ecological niche dimensions, though few studies have examined isotopic response of an ecological community with respect to resource gradients such as fluctuations in prey availability. Stable carbon and nitrogen isotopes were measured for Lake Michigan salmonines and their prey collected from 2014 to 2016. Bayesian ellipse and mixing model analyses were used to quantify isotopic niche characteristics and diets, respectively, among species and years. During the three-year study period, abundance and size structure of preferred alewife

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