Готові списки джерел за темами / S isotopes

Добірка наукової літератури з теми "S isotopes"

Автор: Grafiati

Опубліковано: 10 грудня 2022

Оновлено: 29 січня 2023

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Статті в журналах з теми "S isotopes"

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 (December 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 conversion process was adequate. To produce gaseous SO2 gas, BaSO4 was thermally decomposed in a vacuum system at 900 ºC in the presence of NaPO3. The isotope determination of S (atom % 34S atoms) was carried out by isotope ratio mass spectrometry (IRMS). In this work, the labeled material (K2(34)SO4) was used to validate the method of isotopic determination of S; the results were precise and accurate, showing the viability of the proposed method.

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Lu, Dawei, Tuoya Zhang, Xuezhi Yang, Peng Su, Qian Liu, and Guibin Jiang. "Recent advances in the analysis of non-traditional stable isotopes by multi-collector inductively coupled plasma mass spectrometry." Journal of Analytical Atomic Spectrometry 32, no. 10 (2017): 1848–61. http://dx.doi.org/10.1039/c7ja00260b.

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Non-traditional stable isotopes, with no clear definition yet, generally refer to isotopes beyond C, H, O, N, and S with small variations in natural stable isotopic compositions, such as isotopes of transition and heavy metal elements.

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Ogbesejana, Abiodun Busuyi, Bo Liu, and Mehdi Ostadhassan. "Stable Isotope Geochemistry of the Organic Elements within Shales and Crude Oils: A Comprehensive Review." Molecules 27, no. 1 (December 22, 2021): 34. http://dx.doi.org/10.3390/molecules27010034.

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Over time, stable isotopes have proven to be a useful tool in petroleum geochemistry. However, there is currently insufficient literature on stable isotope geochemistry of the organic elements within shales and crude oils in many petroleum systems around the world. As a result, this paper critically reviews the early and recent trends in stable isotope geochemistry of organic elements in shales and crude oils. The bulk and compound-specific stable isotopes of H, C, and S, as well as their uses as source facies, depositional environments, thermal maturity, geological age, and oil–oil and oil–source rock correlation studies, are all taken into account. The applications of the stable isotopes of H and C in gas exploration are also discussed. Then, the experimental and instrumental approaches to the stable isotopes of H, C, and S, are discussed.

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Gaigalas, Algirdas, and Stanislaw Halas. "Stable Isotopes (H, C, S) and the Origin of Baltic Amber." Geochronometria 33, no. -1 (January 1, 2009): 33–36. http://dx.doi.org/10.2478/v10003-009-0001-9.

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Stable Isotopes (H, C, S) and the Origin of Baltic Amber New results of isotope analysis of light elements (H, C and S) of a dozen Baltic amber samples are described and discussed. Carbon isotope composition was nearly constant (ca. -23‰), whereas sulphur and hydrogen varied in their isotope compositions from +4 to -28‰ and from -171 to -213‰, respectively. The formation and subsequent evolution of this material since its origin in Paleogene time until present is outlined.

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Barrick, Reese E. "Isotope Paleobiology of the Vertebrates: Ecology, Physiology, and Diagenesis." Paleontological Society Papers 4 (October 1998): 101–37. http://dx.doi.org/10.1017/s1089332600000413.

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Isotopic studies of vertebrate material have a short history, while isotopic analyses of invertebrates originated in the 1940's. Interestingly, the driving force behind Harold Urey's desire to derive a carbonate paleotemperature scale in the 1940's and 1950's was the hope that it would solve the mystery of dinosaur extinction by demonstrating temperature changes at the K/T boundary. The most useful and commonly investigated stable isotopes for paleobiologic studies of vertebrates are carbon, nitrogen and oxygen. Oxygen is available from the inorganic bone or tooth apatite phase. Carbon is most often derived from tooth enamel carbonate or organic collagen, and nitrogen is derived from collagen. Each of these stable isotopes provides information on different aspects of an animal's biology and when combined, provide powerful analyses for ecological and evolutionary reconstructions. In the 1970's, much work was done describing the carbon and nitrogen variations in plants. This period was followed in the late 1970's and early 1980's by research on these isotopic variables in mammals (e.g., DeNiro and Epstein, 1978, 1981; Vogel, 1978; Van der Merwe, N.J., 1982). The utility of these isotopes for dietary recognition led to their extensive investigation in archeological studies. Not until the mid to late 1980's and 1990's have these isotopes been utilized in both the inorganic component of teeth and bones as well as the organic component of bones in Pleistocene and older paleobiologic studies. The 1980's also saw the emergence of research on the oxygen isotopic variations in mammals. However, the focus of isotopic studies on vertebrates was not for paleobiologic purposes, but rather, for attempts to derive paleohydrologic or paleoclimatic information from them (e.g., Longinelli, 1984; Luz et al., 1984).

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Benbow, Timothy J., Alan R. Hayman, Robert Van Hale, and Russell Frew. "Preparation of aqueous fatty acids for hydrogen and carbon stable isotope analysis by solid phase extraction." Marine and Freshwater Research 64, no. 4 (2013): 294. http://dx.doi.org/10.1071/mf12192.

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Stable isotope analyses of fatty acids in environmental waters provides important information as to their source(s). Analysis is often confounded due to low concentrations of fatty acids and/or a complex sample matrix requiring separation of the target analyte. The purpose of this study was to validate a method to extract fatty acids from natural waters using solid phase extraction (SPE) before compound specific isotope analysis (CSIA). Three SPE cartridges and multiple eluting solvents were tested to determine the efficiency, isotopic fractionation, and reproducibility of each extraction technique. Our results indicated that surface-modified styrene divinylbenzene cartridges, when eluted with methanol, caused negligible fractionation of the hydrogen isotopes and minimal fractionation of the carbon isotopes, but that isotopic fractionation occurred when compounds were only partially eluted from SPE cartridges. Compounds were also extracted from landfill leachate using both SPE and liquid–liquid extraction (LLE). The hydrogen isotope composition (δ2H) of compounds extracted from water using either method were within experimental precision and the carbon isotope composition (δ13C) of all but one fatty acid were within experimental precision. Therefore, these experiments prove the aforementioned SPE methods to be a convenient and precise method to extract fatty acids from natural waters before CSIA.

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Miller, J. J., G. J. Beke, S. Pawluk, and H. R. Krouse. "Sulfur and oxygen isotopic composition of sulfates at two saline sites in southern Alberta." Canadian Journal of Soil Science 73, no. 4 (November 1, 1993): 633–37. http://dx.doi.org/10.4141/cjss93-061.

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Possible sources of SO4 in soil, drift and bedrock at two saline sites in southern Alberta were investigated using sulfur and oxygen isotope analyses. Slight differences (0.6–5.2 per mil) between δ34S values of SO4 and insoluble S in the geologic material were attributed to kinetic fractionation during oxidation of organic S. Negative δ18O values of SO4 in the shallow (<6 m) bedrock, drift and soil reflected oxidation of reduced S. In contrast, positive δ18O values in the deep (>6 m) bedrock indicated sulfate reduction. The exact source of SO4 could not be determined in this preliminary study. The isotope approach, however, shows promise and warrants more detailed study. Key words: Salinization, sulfates, sulfur isotopes, oxygen isotopes

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Dyachenko A. A., Blashenkov N. M., Berdnikov A. S., Gall L. N., Samsonova N. S., Semenov A. A., and Gall N. R. "Specialized mass spectrometer for determining the isotopic composition of lithium by ERIAD (electrospray with in source atomization)." Technical Physics Letters 48, no. 7 (2022): 1. http://dx.doi.org/10.21883/tpl.2022.07.54025.18919.

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A specialized isotope mass spectrometer for determining the isotopic ratio of lithium by ERIAD (electrospray with atomization in an ion source) is described. The device uses a Mattuha-Herzog-type mass analyzer with double focusing to use ion beams with a large spread in energy and simultaneous registration of signals of both lithium isotopes (6Li and 7Li), and a two-channel receiver based on a doublet of microchannel plates. The gas-dynamic interface is built according to the Kontorowitz-Gray scheme; from the gas-dynamic point of view, it is "long", that is, the distance between the nozzle and the skimmer is 4 times the size of the "Mach barrel" at the operating pressure (200 Pa). The device is desktop, its weight does not exceed 20 kg. The measurement time is 1000 s, sample replacement time is 100 s, measurement accuracy is ~ 0.1%. Keywords: mass spectrometry, electrospray, ion source, isotopes of lithium.

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Herbstritt, Barbara, Benjamin Gralher, and Markus Weiler. "Continuous, near-real-time observations of water stable isotope ratios during rainfall and throughfall events." Hydrology and Earth System Sciences 23, no. 7 (July 17, 2019): 3007–19. http://dx.doi.org/10.5194/hess-23-3007-2019.

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Abstract. The water isotopic composition of throughfall is affected by complex diffusive exchange with ambient water vapour, evaporative enrichment of heavy isotopes, and mixing processes in the tree canopy. All interception processes occur simultaneously in space and time, generating a complex pattern of throughfall depth and water isotopic composition. This pattern ultimately cascades through the entire hydrologic system and is therefore crucial for isotope studies in catchment hydrology, where recharge areas are often forested, while reference meteorological stations are generally in the open. For the quasi real-time observation of the water isotopic composition (δ18O and δ2H) of both gross precipitation and throughfall, we developed an approach combining a membrane contactor (Membrana) with a laser-based Cavity Ring-Down Spectrometer (CRDS, Picarro), obtaining isotope readings every 2 s. A setup with two CRDS instruments in parallel analysing gross precipitation and throughfall simultaneously was used for the continuous observation of the temporal effect of interception processes on the stable isotopes of water. All devices were kept small to minimize dead volume with time lags of only 4 min for water from the rainfall collectors to the isotope analysers to increase the temporal resolution of isotope observations. Complementarily, meteorological variables were recorded at high temporal resolution at the same location. The achieved evolution from discrete liquid or event-based bulk samples to continuous measurements allows for direct comparison of water stable isotope data with common meteorological measurements. Future improvements of the spatial representativeness will make our approach an even more powerful tool towards detailed insight into the dynamic processes contributing to interception during rainfall events.

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Lin, Mang, Xiaolin Zhang, Menghan Li, Yilun Xu, Zhisheng Zhang, Jun Tao, Binbin Su, Lanzhong Liu, Yanan Shen, and Mark H. Thiemens. "Five-S-isotope evidence of two distinct mass-independent sulfur isotope effects and implications for the modern and Archean atmospheres." Proceedings of the National Academy of Sciences 115, no. 34 (August 6, 2018): 8541–46. http://dx.doi.org/10.1073/pnas.1803420115.

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The signature of mass-independent fractionation of quadruple sulfur stable isotopes (S-MIF) in Archean rocks, ice cores, and Martian meteorites provides a unique probe of the oxygen and sulfur cycles in the terrestrial and Martian paleoatmospheres. Its mechanistic origin, however, contains some uncertainties. Even for the modern atmosphere, the primary mechanism responsible for the S-MIF observed in nearly all tropospheric sulfates has not been identified. Here we present high-sensitivity measurements of a fifth sulfur isotope, stratospherically produced radiosulfur, along with all four stable sulfur isotopes in the same sulfate aerosols and a suite of chemical species to define sources and mechanisms on a field observational basis. The five-sulfur-isotope and multiple chemical species analysis approach provides strong evidence that S-MIF signatures in tropospheric sulfates are concomitantly affected by two distinct processes: an altitude-dependent positive 33S anomaly, likely linked to stratospheric SO2 photolysis, and a negative 36S anomaly mainly associated with combustion. Our quadruple stable sulfur isotopic measurements in varying coal samples (formed in the Carboniferous, Permian, and Triassic periods) and in SO2 emitted from combustion display normal 33S and 36S, indicating that the observed negative 36S anomalies originate from a previously unknown S-MIF mechanism during combustion (likely recombination reactions) instead of coal itself. The basic chemical physics of S-MIF in both photolytic and thermal reactions and their interplay, which were not explored together in the past, may be another ingredient for providing deeper understanding of the evolution of Earth’s atmosphere and life’s origin.

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Більше джерел

Дисертації з теми "S isotopes"

Salgado, Souto Sergio Adrian, and Souto Sergio Adrian Salgado. "A Re-Os Geochronology and Multi Stable Isotope (C, N, S, Sr, Pb) Systematics of Source Rocks and Crude Oils from the Sonda de Campeche Petroleum System, Mexico." Diss., The University of Arizona, 2018. http://hdl.handle.net/10150/626760.

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In this work, I present a multi-isotopic study (carbon, nitrogen, sulfur, strontium and lead) and Re-Os geochronology in rocks and crude oils of the Sonda de Campeche Petroleum System (SCPS). Since crude oils are complicated chemical systems easily disturbed, the Re-Os isotopic system could be affected if secondary processes perturb crude oils. Therefore, the multi stable isotopic study allows the identification of the presence and grade of these secondary processes in crude oils. The δ13C values of crude oils from the SCPS distinguish between: 1) crude oils with the fingerprint of source rocks of hydrocarbons (-28.3 to -26.7 ‰), and 2) crude oils with the fingerprint of the reservoir rocks (-25.5 to -24.9 ‰). Similarly, the δ15N values reveal that crude oils, during migration or trapping processes mimic the isotopic composition of the reservoir rocks of the Ek-Balam Formation. Furthermore, the δ34S values of crude oils from the SCPS (-8.0 to -2.5 ‰) show an absence of a thermal sulfate reduction (TSR) signature, which likely means that the use of Re-Os systematics in crude oils and rocks in the SCPS is appropriate. Strontium and lead measurements show crude oils have an isotopic composition different from rocks from the Edzna Formation but similar to rocks of the Akimpech and Ek-Balam formations, indicating that crude oils received Sr and Pb from the trapping rocks during migration or trapping processes, producing a isotopic mixing trend with rocks of these formations. Specifically, the lead isotope composition allows the identification of a source of lead never recorded before, the Guichicovi Complex. The isotopic data suggest that this Grenville Complex has been feeding with detrital material to the sedimentary rocks from Bacab, Ek-Balam and Akimpech formations in the SCPS, and in consequence contributing to the final isotopic composition of crude oils as well. Re-Os geochronology of rocks from the Edzna and Akimpech formations (152 ± 4 Ma; and 158.6 ± 5.5 Ma, respectively) provides precise ages of deposition that coincide with the ages proposed in previous studies based on the fossil record. Re-Os geochronology in crude oils yield ages with low uncertainty and moderate MSWD values, reflecting a rapid formation and migration process that occurred during evolution of the SCPS. The age of crude oils (28.3 ± 5.5 Ma) broadly agrees with petroleum generation models proposed by PEMEX.

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Herreros, Julien. "Interprétations sur le dernier siècle du profil isotopique de l'eau dans deux carottes de glace andines (Coropuna, Pérou, 15°s et San Valentin, Chili, 46°s)." Thesis, Montpellier 2, 2010. http://www.theses.fr/2010MON20026/document.

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Ce travail de thèse est centré sur l'analyse des compositions isotopiques de la glace (d18O et dD) de deux nouvelles carottes de glace longues provenant des régions subtropicale et tempérée des Andes. La première carotte, longue de 42m, a été extraite en 2003 au col du glacier Coropuna au Pérou (72°39'W, 15°32'S, 6425m) et la deuxième de 122m au sommet du glacier San Valentin au Chili (46°35'S, 73°19'W, 4032m) en 2007. L'étude a porté sur la représentativité du signal isotopique comme archive du climat sur le dernier siècle, correspondant à la totalité de la carotte du Coropuna et les 70 premiers mètres au San Valentin, dans deux régions climatiques différentes. Nous avons observé que les enregistrements des signaux isotopiques sont affectés par des processus de post-dépôt. Au col du Coropuna, le signal est lissé par homogénéisation en dessous de 3m de profondeur à cause de la percolation d'eau de fonte et de la diffusion isotopique via un flux de vapeur, et aucune interprétation climatique n'est possible à partir du signal isotopique. Au so mmet du San Valentin, les vents forts, présents toute l'année, érodent et/ou redistribuent la majorité des précipitations annuelles en créant certainement des hiatus sur une voire plusieurs années ou, au contraire, des dépôts exceptionnels de plusieurs mètres. Ces conditions rendent l'identification des cycles isotopiques annuels difficile et aucune relation entre les isotopes et les paramètres climatiques n'a pu être établie due à une datation très incertaine
This work is focused on the analyses of two new isotopic records (d18O and dD) from Andean ice cores in the subtropics and temperate latitudes. The first 42 m-long ice core was extracted in 2003 from the saddle of Coropuna glacier in Peru (72°39'W, 15°32'S, 6425 m), and the second 122 m-long core in 2007 from the San Valentin summit in Chile (46°35'S, 73°19'W, 4032 m). The isotopic signals were investigated for their suitability as climate archives over the last century, covering the 42 m-long ice core from Coropuna and the first 70 meters of the core from San Valentin, in two different climatic regions. We observed that the isotopic records are affected by post-depositional processes. At the saddle of Coropuna, isotopic homogenization occurs below 3 m as a result of meltwater percolation and isotopic diffusion, and thus the climatic interpretation is not possible. At the San Valentin summit, removal and/or re-deposition of snow by strong winds occurring throughout the year may create a lack of one or more annual snow layers or, on the other hand, may cause unexpected deposits of several meters. Due to these potential conditions, we cannot always identify the annual isotopic cycles and the isotopes histories show no significant correlation with the climatic parameters because of an uncertain dating

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Rouxel, Olivier. "Géochimie isotopique des métaux (Fe, Cu, Sb) et des metalloides (S, Se) dans la croûte océanique." Vandoeuvre-les-Nancy, INPL, 2002. http://www.theses.fr/2002INPLA43N.

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Cette étude s'est intéressée à la recherche de nouveaux traceurs isotopiques (Fe, Cu, Se, Sb) des processus hydrothennaux océaniques (Site Lucky Strike, dorsale médio-Atlantique) et de l'altération des basaltes océaniques (Site ODP 801, Pacifique Ouest). L'objectif majeur a été d'explorer la possibilité d'utiliser ces systèmes isotopiques pour appréhender à la fois les processus chimiques et les processus biologiques dans ces environnements. Ce travail a nécessité la mise au point des protocoles analytiques des mesures isotopiques par ICP-MS multicollecteur Isoprobe. L'étude de la composition isotopique du Se dans les sulfures hydrothermaux océaniques montre des variations jusqu'à 8[pour mille], et avec l'analyse couplée des isotopes du S, permet d'apporter des informations importantes sur les processus biologiques et chimiques des environnements de subsurface. Les isotopes du Fe des sulfures hydrothermaux varient de plus de 4[pour mille], et sont influencés par les processus de précipitation de sulfures en profondeur. En revanche, les isotopes du Cu fractionnement préférentiellement pendant l'altération des sulfures de Cu dans les environnements des cheminées. , Les compositions isotopiques du S des sulfures secondaires dans la croûte océanique altérée variant entre 0 et -40[pour mille] sont en accord avec des fractionnements bactériens associés à la biosphère profonde. L'étude couplée avec les isotopes du Se apporte des contraintes supplémentaires sur les modèles de fractionnement des isotopes du S. Les valeurs isotopiques du Fe dans la croûte océanique varient de plus de 4[pour mille] et sont expliquées par (1) le lessivage préférentiel du 54Fe lors de l'altération et (2) l'oxydation partielle du Fe2+ et la précipitation d'hydroxydes de Fe dans les veines des basaltes, enrichis en 57Fe. La distinction entre des processus biologiques et abiotiques grâce aux isotopes du S, Se, Fe et Cu est donc possible mais des expériences en laboratoire des fractionnements isotopiques de ces éléments sont maintenant requises.

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Yu, Huimin. "Li, Hf and Os Isotope Systematics of Azores Basalts and A New Microwave Digestion Method for Os Isotopic Analysis." Miami University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=miami1322847998.

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Dogramaci, Shawan Shawket. "Isotopes of sulphur, oxygen, strontium and carbon in groundwater as tracers of mixing and geochemical processes, Murray Basin, Australia /." Title page, table of contents and abstract only, 1998. http://web4.library.adelaide.edu.au/theses/09PH/09phd654.pdf.

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Almeida, J. [Verfasser]. "The capture cross sections of the neon isotopes and the s-process neutron balance / J. Almeida." Karlsruhe : KIT-Bibliothek, 2013. http://d-nb.info/1196023824/34.

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Abdallah, Maha. "Etude de l’allocation et de la mobilisation du soufre (S) chez le colza d’hiver (Brassica napus L. ) soumis à une oligotrophisation en S." Caen, 2010. http://www.theses.fr/2010CAEN2069.

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Le colza (Brassica napus L. ) est usuellement considéré comme étant sensible à une limitation en soufre (S) qui affecte négativement sa croissance. Peu d’études ayant cependant été consacrées à l’impact d’une limitation en S, son effet a été évalué sur i) la production de biomasse, ii) l’expression relative des systèmes de transport du nitrate et du sulfate, iii) leur absorption racinaire par marquage 15N et 34S, iv) la remobilisation du N et du S et v) la dynamique de sénescence foliaire pendant le stade de croissance végétative. Les résultats ont montré que lors d’une limitation en S à court terme et avec des réserves S initiales suffisantes, le colza est capable de maintenir sa croissance grâce à un recyclage des réserves S endogènes (essentiellement sous forme de sulfate) des vieilles feuilles, parallèle à une induction de l’expression des gènes codant des transporteurs de sulfate tonoplastiques et à une ré-orientation préférentielle des flux de S absorbé et de S remobilisé des feuilles vers les racines, Ce n’est qu’avec des réserves S initiales et une disponibilité en S faibles (i. E. Imitation en S de long terme) que la croissance, l’absorption de nitrate et l’expression de l’un de ses transporteurs ont été réduites. De plus, les teneurs en protéines foliaires, le S total, l’absorption de S, et les teneurs en sulfate dans les feuilles les plus vieilles ont été réduits malgré une sur-expression des transporteurs de sulfate tonoplastiques. Par rapport aux témoins, la limitation en S induit un retard de la sénescence appréhendé par l’analyse d’indicateurs moléculaires et de la dégradation des protéines foliaires. L’ensemble des résultats montre que les effets de la limitation en S doivent être appréhendés en prenant en compte le statut initial en S de la plante, et en particulier la teneur en sulfate des feuilles. Nos résultats suugèrent de nouvelles perspectives pour l’amélioration de l’efficience d’utilisation du S et du N en raison de l’inter-connection entre les deux métabolismes
Oilseed rape (Brassica napus L. ) is supposed to be sensitive to S limitation which negatively affects growth. Nevertheless, as little studies clearly assessed the impact of short or long term mineral S limitation, we analyzed its effects on i) biomass production, ii) N and S uptake by , 15N and 34S labelling iii) relative gene expression of nitrate and sulphate transport systems, iv) N and S remobilization and v) leaf senescence dynamics during vegetative growth. The results showed that under short term S limitation and with sufficient initial S reserves, oilseed rape is able to maintain its growth according to the recycling of endogenous S reserves (mostly as sulphate) from old leaves while in the meantime, gene expression encoding sulphate tonoplastic transporters were up-regulated. S fluxes from uptake and S remobilization from leaves were mostly allocated to the roots. Only with both low initial S reserves and low mineral S availability (i. E. Long term S limitation), plant growth was reduced while one of the nitrate transporter gene expressions was steadily down-regulated and root nitrate uptake was also reduced. Moreover, leaf soluble proteins contents, total S, S recently taken up as 34S and sulphate contents in oldest leaves declined despite an up-regulation of the expression of genes encoding plasmalemmic or tonoplastic sulphate transporters. Compared to control plants, S limitation also delayed leaf senescence evaluated by molecular indicators and leaf protein degradation. Overall results demonstrated that the effect of S limitation should be estimated by taking into account plant initial S status, and particularly the sulphate content within the oldest leaves. Our results gave new perspectives for the improvement of Sulphur Use Efficiency and Nitrogen Use Efficiency, because of the tigh inter-connection between theses two metabolisms

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Nabbefeld, Birgit. "Biomarker distributions and stable isotopes (C, S, H) to establish palaeoenvironmental change related to the end-Permian mass extinction event." Thesis, Curtin University, 2009. http://hdl.handle.net/20.500.11937/493.

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Extinction, the irreversible loss of species, is perhaps the most alarming symptom of the ongoing biodiversity crisis. Some of the most significant changes in evolution throughout Earth’s history have coincided with extinction boundary events. In this thesis various organic geochemical (biomarker and stable isotopes) and geological (sedimentology and palaeontology) approaches have been undertaken to examine one of the most significant mass extinction events that occurred during the Late Permian (252 My ago) near to the Permian/Triassic (P/Tr) boundary. In the marine realm 49% of invertebrate families became extinct (equivalent to 80–96% of species loss). However, identifying an ecological crisis and associated extinction interval in any given extinction boundary section can often be difficult.Many different hypotheses have been proposed to explain the end-Permian extinction. The coincidence in timing of the extinction with the massive volcanic eruptions in Siberia has been established. The release of methane and possibly other gases during the volcanic event could have led to global warming. The oceans were oxygen deficient leading to euxinic conditions (with H[subscript]2S as a toxic agent) possibly triggering the extinction. Further, the selectivity of the extinction suggests hypercapnia (high CO[subscript]2) as a kill mechanism. It is widely accepted that the extinction is a “tangled web of causality” with several mechanisms contributing to the biotic crisis.Analyses of molecular fossils (biomarkers) and their stable isotopic compositions provide an alternative tool for identifying mass extinction intervals complimenting bulk stable isotopic data (δ[superscript]34Spyrite, δ[superscript]13Ccarbonate, δ[superscript]13Corg), sedimentological and fossil record data. Only recently have biomarker abundances (and δ[superscript]13C) and changes associated with the end-Permian extinction attracted significant attention. For example, biomarkers ultimately derived from pigments of organisms carrying out anoxygenic photosynthesis (Chlorobiaceae) have been recently reported in several P/Tr sections, providing evidence for widespread photic zone euxinic conditions.The aims of this PhD thesis were (i) to establish the palaeoenvironmental conditions associated with the P/Tr mass extinction event using an integrated biomarker, isotopic (including δD of biomarkers) and sedimentological approach for one section from the northern hemisphere and (ii) to establish whether the biomarker and isotopic signals (including δD of bulk kerogen) observed in several sections from about the globe represent localised environments of deposition and/or are related to global depositional conditions.In Chapter 2 for the first time an integrated study including sedimentological data, biomarker distributions/abundances and selected stable carbon and hydrogen isotopes along with bulk isotopes (δ[superscript]34Spyrite, δ[superscript]13Ccarbonate, δ[superscript]13Corg) for a Late Permian section from Lusitaniadalen, Spitsbergen, Norway has been conducted. These data support a marine transgression and collapse of the marine ecosystem in the Late Permian. Strong evidence for waxing and waning of photic zone euxinic conditions throughout the Late Permian section is provided by Chlorobiaceae-derived biomarkers (including δ[superscript]13C data) and δ[superscript]34Spyrite, suggesting several events of H[subscript]2S outgassing and potentially several pulses of extinction. A rapid decrease in abundance of various land plant biomarkers prior to the marine collapse event suggests a decline in terrestrial organisms during the Late Permian and/or increasing distance from the palaeoshoreline as an effect of sea level rise. Changes in δD of biomarkers also indicate a change in source of OM, microbial diversification and sea level rise. Further, compound specific isotope analysis (CSIA) data of algal and land-plant derived biomarkers, δ[superscript]13Ccarbonate and δ[superscript]13Corg provide strong evidence for synchronous changes in δ[superscript]13C of marine and atmospheric CO[subscript]2, attributed to a [superscript]13C-depleted source. The source could either be associated with isotopically depleted methane released from the melting of gas clathrates and/or from respired OM, due to the collapse of the marine ecosystem.In Chapter 3 δD of kerogen (δDkerogen) for three P/Tr sequences (Hovea#3, Perth Basin, Western Australia; Schuchert Dal section, Jameson’s Land, East Greenland and Lusitaniadalen, Spitsbergen) have been measured and compared with δ[superscript]34S of total reduced inorganic sulfur (δ[superscript]34Spyrite) of all three sections and for one sample set δ[superscript]13C of carbonate (δ[superscript]13Ccarbonate) to establish (i) similarities between the sections and (ii) evaluate whether these signals are local or global. Stable isotope shifts occur for all localities either at the P/Tr transition (Western Australia) or coinciding with the marine ecosystem collapse (Spitsbergen and East Greenland). δDkerogen reflects OM/kerogen type. Reliable palaeoenvironmental information in terms of the use of δD can therefore only be obtained for the P/Tr transition from hydrogen compound-specific isotope analyses of biomarkers (Chapter 2). The negative shifts in δ[superscript]13Ccarbonate (primary) and δ[superscript]13Ckerogen are attributed to the release of [superscript]13C-depleted carbon into the atmosphere, whereas the isotopic excursions in δ[superscript]34Spyrite relate to global palaeoredox changes. However, the global synchronous shifts in δDkerogen, δ[superscript]34Spyrite and δ[superscript]13Ckerogen for all sections suggest a relation between the sulfur, carbon and hydrogen cycles.In Chapter 4 the abundances of several polycyclic aromatic hydrocarbons (PAHs) throughout three P/Tr sections from the Global Stratotype Section and Point (GSSP) in Meishan (South China), Kap Stosch Area (East Greenland) and Peace River Basin (Western Canada) were evaluated. The PAHs dibenzothiophene and dibenzofuran were found to decrease in abundance just before or shortly after the P/Tr boundary in all three sections, supporting the hypotheses of a worldwide decrease in preservation of terrestrial OM. Perylene was observed in high abundance at the onset of the main extinction horizon (at bed 25) in Meishan and has been attributed to a wood degrading fungal source, consistent with the demise of land plants. Frequently occurring forest fire events are also evident from the abundance of several combustion-derived PAHs showing independent patterns in all sections. The coincidence of high abundances of combustion markers occurring simultaneous with ash beds in Meishan section indicates an origin related to the Late Permian and Early Triassic volcanic eruptions in Siberia and China.In Chapter 5 an evaluation of selected biomarker maturity parameters [methylnaphthalene ratio (MNR), methylphenanthrene index (MPI-1), C27 diasterane/sterane ratio and Ts/(Ts+Tm) ratio] has been conducted for a number of P/Tr samples (Western Australia, East Greenland and Spitsbergen). Differences in these parameters have been observed between freely extractable bitumens from sedimentary rocks (Bitumen I) and bitumens comprising hydrocarbons closely related to the kerogen/mineral matrix (Bitumen II). Further, a distinct connection between these differences and the clay/TOC ratio of the sediments has been made. The information on thermal maturity that is preserved within Bitumen II could be of significance in petroleum exploration studies, as the original thermal maturity signal of Bitumen I may be overprinted by migrated bitumen.

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Salesse, Kevin. "Archéo-biogéochimie isotopique, reconstitutions des régimes alimentaires et des schémas de mobilité, et interactions bioculturelles. Les sépultures plurielles de la catacombe des Saints Pierre-et-Marcellin (Rome, Ier-IIIe s. ap. J.-C.) : Les sépultures plurielles de la région X de la catacombe des Saints Pierre-et-Marcellin (Rome, Ier-IIIe s. ap. J.-C.)." Thesis, Bordeaux, 2015. http://www.theses.fr/2015BORD0412/document.

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Entre 2003 et 2010, dans la région centrale nommée X de la catacombe des Saints Pierre-et-Marcellin à Rome, a été découvert et en partie fouillé un ensemble de sépultures plurielles inédites (Ier-IIIe s. ap. J.-C.) contenant plusieurs centaines d’individus, lesquels ont été inhumés selon des pratiques funéraires singulières à la suite d’un épisode de surmortalité de nature probablement épidémique. Pour appréhender l’histoire de vie (alimentation et mobilité) de ces défunts et rediscuter sur la base d’éléments nouveaux certaines hypothèses préalablement établies, nous avons mené dans le cadre de ce travail une approche archéo-biogéochimique multi-proxy (14C, δ13C, δ15N, δ18O et 87Sr/86Sr) et multi-tissulaire (émail, os, cheveu) sur un échantillon de 130 individus issus de six différentes chambres. Nous avons dans un premier temps vérifié l’intégrité biochimique et isotopique des fractions minérales (phases carbonatées) et organiques (phases collagénique et kératinique) des échantillons à partir d’indicateurs classiques mesurés en routine (%Col, %C, %N, C/N, PCO2 et PCO2/Masse) et par spectroscopie IRTF (IRSF, CO3/PO4 et AmideI/PO4) et par une approche innovante consistant en des datations 14C sur couples collagène-apatite pour valider le signal isotopique des fractions minérales. Nos résultats mettent en évidence des différences extrêmes de préservation de toutes les phases. La trajectoire diagénétique des échantillons n’est toutefois pas aléatoire mais dépendante des conditions environnementales et taphonomiques différant entre les petites et les grandes chambres. En outre, nous avons pu démontrer qu’en dépit de fortes recristallisations et d’échanges isotopiques avec l’environnement sépulcral, les phases carbonatées possèdent un signal isotopique biogénique non altéré. Nous avons dans un second temps reconstruit les régimes alimentaires des individus en nous appuyant sur des référentiels de comparaisons robustes ainsi que divers modèles interprétatifs (mono-proxys versus multi-proxys ; qualitatifs versus quantitatifs), lesquels ont été dans certains cas adaptés au besoin de notre étude. D’une façon générale, nos résultats montrent que l’essentiel des individus a eu accès à un régime alimentaire type fondé sur la triade Céréales C3/Viande C3/Poisson marin. Ce régime alimentaire type n’est toutefois pas exclusif, certains individus (n = 13) ayant consommé de façon occasionnelle d’autres catégories de ressources tels que du poisson dulcicole ou des céréales C4. Nos résultats révèlent que les changements d’alimentation au cours de la vie sont relativement limités. Par ailleurs, cette population se singularise sur un plan strictement alimentaire au regard des autres populations contemporaines romaines pour lesquelles des valeurs isotopiques sont publiées. Nous avons dans un troisième temps étudié les schémas de mobilité des individus en nous fondant sur une approche rigoureuse de nos données et sur des référentiels de comparaison les plus exhaustifs possible ainsi qu’en tenant compte de biais ordinairement éludés (faits culturels, influence du climat et erreurs associées aux équations de conversion). Nos résultats mettent en lumière qu’a minima 23 % (n = 30) des individus étudiés sont migrants. Ces derniers ne se distinguent toutefois pas de par leur alimentation des résidents romains. Nous avons pu montrer en outre que ces migrants ont eu des trajectoires de vie complexes et hétérogènes et que trois schémas de mobilité distincts les caractérisent. Notre population ne se différencie pas en termes de taux de migrants des autres populations romaines pour lesquelles des données isotopiques sont disponibles. Elle se distingue en revanche par son cosmopolitisme avec des origines pour les migrants des plus diverses : Europe, Afrique, Arabie et Asie mineure [...]
An assembly of unpublished complex plural burials (1st-3rd cent. AD.) was discovered and partially excavated, between 2003 and 2010 in the central region called X of the catacomb of Saints Peter and Marcellinus in Rome. It contains several hundred individuals which were buried according to uncommon funeral practices following a mortality episode of likely epidemic nature. To understand the life history (diet and mobility patterns) of these deceased and to discuss again certain assumptions previously established on the basis of new evidences, we have as part of this work conducted an archaeo-biogeochemical multi-proxy (14C, δ13C, δ15N, δ18O et 87Sr/86Sr) and multi-tissue (enamel, bones, hair) approach on a sub-sample of 130 individuals coming from six different chambers. At the outset, we tested the biochemical and isotopic integrity of mineral (carbonate phases) and organic fractions (collagen and keratin phases) samples from conventional indicators measured in routine (%Col, %C, %N, C/N, PCO2 et PCO2/Mass), by FTIR spectroscopy (IRSF, CO3/PO4 and AmideI/PO4) and by an innovative approach consisting of 14C dating on collagen-apatite to validate the isotopic signal of mineral fractions. Our results highlight extreme differences of preservation of all phases. Diagenetic trajectory of samples is however not random but dependent on environmental and taphonomical conditions which differ between small and large chambers. Furthermore, we have been able to demonstrate that, despite strong recrystallization and isotopic exchanges with the sepulchral environment, carbonated phases have an unaltered biogenic isotopic signal. Secondly, we rebuilt the diets of individuals based on robust comparisons repositories and various interpretative models (mono-proxy versus multi-proxies; qualitative versus quantitative) which were, in some cases, adapted to the needs of our study. In general, our results show that most of the individuals had access to such a type diet based on the triad Cereals C3/Meat C3/Marine fish. This type diet would however not be exclusive, some individuals (n = 13) would have indeed occasionally consumed other resources such as freshwater fish or C4 cereals. Our results indicate that changes of diet during the life history are relatively limited. Besides, with regard to consumed food, this population is distinguished from other contemporary Roman populations for whom isotopic values are published. In the third place, we studied individual’s mobility patterns based on a rigorous approach to our data and on a comparison of the most comprehensive repositories as possible with taking into account the bias usually evaded (cultural facts, influence of climate and errors associated with conversion equations). Our results highlight that a minimum of 23% (n = 30) of the studied individuals are migrants. These, however, are not distinguished from Roman residents through their diet. We were able to show further that these migrants had complex and heterogeneous trajectories during their life within three distinct mobility patterns characterizing them. In terms of migrant’s rates, our population does not differ from other Roman populations for which the isotopic data are available. It differs however by its cosmopolitanism with origins for more diverse migrants: Europe, Africa, Arabia and Asia Minor [...]
Tra il 2003 e il 2010, nella regione centrale chiamata X della catacomba dei Santi Pietro e Marcellino a Roma, è stato scoperto e parzialmente scavato un insieme di sepolture plurime inedite (I-III sec. D.C.) contenente diverse centinaia di individui, i quali sono stati inumati secondo le pratiche funerarie singolari in seguito ad un episodio di sovramortalità di natura probabilmente epidemica. Per comprendere la storia di vita (alimentazione e mobilità) di questi defunti e ridiscutere, sulla base di nuovi elementi, alcune ipotesi precedentemente formulate, abbiamo condotto, nel quadro di questo lavoro, un approccio archeo-biogeochimico multi-proxys (14C, δ13C, δ15N, δ18O e 87Sr/86Sr) e multi-tessuto (smalto, ossa, capelli) su un campione di 130 individui da sei stanze diverse. Abbiamo inizialmente verificato l'integrità biochimica e isotopica delle frazioni minerali (fasi carbonatiche) ed organiche (fasi collageniche e cheratiniche) dei campioni provenienti da indicatori classici misurati in routine (%Col, %C, %N, C/N, PCO2 e PCO2/Massa) e per spettroscopia FTIR (IRSF, CO3/PO4 e AmmideI/PO4) ed un approccio innovativo costituito da datazione 14C su coppie collagene-apatite per validare il segnale isotopico delle frazioni minerali. I nostri risultati mettono in evidenza delle differenze estreme di preservazione di tutte le fasi. La traiettoria diagenetica dei campioni non è però aleatoria, ma dipendente dalle condizioni ambientali e tafonomiche che differiscono tra camere piccole e grandi. Inoltre, abbiamo potuto dimostrare che nonostante delle forti ricristallizzazioni e degli scambi isotopici con l'ambiente sepolcrale, le fasi carbonatiche hanno un segnale isotopico biogenetico inalterato. Abbiamo in un secondo tempo ricostruito i regimi alimentari degli individui basandoci su riferimenti di confronto robusti e vari modelli interpretativi (mono-proxys versus multi-proxys, qualitativi versus quantitativi), i quali sono stati in alcuni casi, adattati alle esigenze del nostro studio. In generale, i nostri risultati mostrano che la maggior parte degli individui ha avuto accesso ad un regime alimentare tipo basato sulla triade Cereali C3/Carne C3/Pesci marini. Questo regime alimentare non è tuttavia esclusivo, avendo certi individui (n = 13) consumato casualmente altre categorie di risorse come il pesce dulciacquicolo o dei cereali C4. I nostri risultati indicano che i cambiamenti di alimentazione nel corso della vita sono relativamente limitati. Inoltre, questa popolazione si distingue da un piano strettamente alimentare rispetto alle altre popolazioni contemporanee romane per le quali dei valori isotopici sono pubblicati. Abbiamo in un terzo tempo studiato gli schemi di mobilità degli individui basandoci su un approccio rigoroso dei nostri dati e su riferimenti di confronto i più esaustivi possibile, e anche tenendo conto di punti di vista solitamente elusi (fatti culturali, influenza del clima e errori associati alle equazioni di conversione). I nostri risultati mettono in luce che a minima 23% (n = 30) degli individui studiati sono migranti. Questi ultimi, tuttavia, non si distinguono per la loro alimentazione dai residenti romani. Abbiamo potuto mostrare, inoltre, che questi migranti hanno avuto percorsi di vita complessi ed eterogenei e che tre schemi di mobilità distinti li caratterizzano. Nostra popolazione non si differenzia in termini di tasso di migranti da altre popolazioni romane per le quali sono disponibili dei dati isotopici. Essa si distingue tuttavia per il suo cosmopolitismo con delle origini per i migranti delle più diverse: Europa, Africa, Arabia e Asia Minore [...]

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Gómez, Vallejo Vanessa. "Development of new strategies for the synthesis of radiotracers labeled with short-lived isotopes: application to 11C and 13N." Doctoral thesis, Universitat Ramon Llull, 2010. http://hdl.handle.net/10803/9301.

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S'ha desenvolupat una nova estratègia per la síntesi ràpida i eficient de L-[metil-11C]metionina basada en el captive solvent method. La reacció de L-homocisteína (dissolució bàsica en aigua/etanol 1:1) amb [11C]CH3I en un loop de HPLC va permetre la formació del radiotraçador desitjat amb elevat rendiment radioquímic (38.4 ± 4.1%) en un temps curt (< 12 min). Tots el paràmetres analítics compleixen les especificacions requerides per la versió actual de la Farmacopea Espanyola, tot i que els valors d'activitat específica obtinguts van ser relativament baixos. Degut a això, es van estudiar i quantificar les principals fonts que contribueixen a la contaminació de carboni-12 durant les síntesis de [11C]CH3I efectuades segons el "wet" method. Es va observar que la principal font de contaminació de CO2 no radioactiu (contribució>90%) és el propi procés de bombardeig, probablement degut a la combustió (causada per les altes temperatures i pressions assolides durant la irradiació) dels compostos que contenen carboni i que es troben al gas irradiat (o a l'interior del blanc). Es van establir procediments generals per realitzar abans, durant i després de la radiosíntesi per prevenir la contaminació exterior i, d'aquesta manera, augmentar l'activitat específica dels radiotraçadors sintetitzats.
En quant al marcatge amb nitrogen-13, s'ha desenvolupat un procés totalment automàtic per a la producció de [13N]NO2- a partir de [13N]NO3- generat en el ciclotró. El precursor radioactiu [13N]NO2- s'ha utilitzat per la radiosíntesi de compostos amb interès biològic com ara S-nitrosotiols (donadors de NO.), N-nitrosamines (molècules amb potencials efectes carcinogènics) i azo compostos (amb possible aplicació com a radiotraçadors per a la detecció in vivo de plaques de β-amiloide). En tots els casos es van obtenir excel·lents conversions radioquímiques (48.7% - 74.5% per S-[13N]nitrosotiols, 45.6% - 53.4% per N-[13N]nitrosamines i 40.0% - 58.3% per 13N-azo compostos) i bons rendiments radioquímics (33.8% - 60.6% per S-[13N]nitrosotiols, 34.0% - 37.8% per N-[13N]nitrosamines i 20.4% - 47.2% per 13N-azo compostos). A més a més, s'ha dissenyat i implementat un mòdul automàtic amb control remot pel marcatge de molècules amb 13N.
Se ha desarrollado una nueva estrategia para la síntesis rápida y eficiente de L-[metil-11C]metionina basada en el captive solvent method. La reacción de L-homocisteína (disolución básica en agua/etanol 1:1) con [11C]CH3I en un loop de HPLC permitió la formación del radiotrazador deseado con elevado rendimiento radioquímico (38.4 ± 4.1%) en un tiempo corto (< 12 min). Todos los parámetros analíticos cumplían las especificaciones requeridas por la versión actual de la Farmacopea Española, aunque los valores de actividad específica obtenidos fueron relativamente bajos. Por ello, se estudiaron y cuantificaron las principales fuentes que contribuyen a la contaminación de carbono-12 durante las síntesis de [11C]CH3I efectuadas según el "wet" method. Se observó que la principal fuente de contaminación de CO2 no radiactivo (contribución>90%) es el propio proceso de bombardeo, probablemente debido a la combustión (causada por las altas temperaturas y presiones alcanzadas durante la irradiación) de los compuestos que contienen carbono y que se encuentran presentes en el gas irradiado (o en el mismo cuerpo del blanco). Se establecieron procedimientos generales para realizar antes, durante y con posterioridad a la radiosíntesis para prevenir la contaminación exterior y, de esta manera, aumentar la actividad específica de los radiotrazadores sintetizados.
Respecto al marcaje con nitrógeno-13, se ha desarrollado un proceso totalmente automático para la producción de [13N]NO2- a partir del [13N]NO3- generado en el ciclotrón. El precursor radiactivo [13N]NO2- se ha utilizado para la radiosíntesis de compuestos con interés biológico tales como S-nitrosotioles (donadores de NO.), N-nitrosaminas (moléculas con potenciales efectos carcinogénicos) y azo compuestos (con posible aplicación como radiotrazadores para la detección in vivo de placas de β-amiloide). En todos los casos se obtuvieron excelentes conversiones radioquímicas (48.7% - 74.5% para S-[13N]nitrosotioles, 45.6% - 53.4% para N-[13N]nitrosaminas y 40.0% - 58.3% para 13N-azo compuestos) y buenos rendimientos radioquímicos (33.8% - 60.6% para S-[13N]nitrosotioles, 34.0% - 37.8% para N-[13N]nitrosaminas y 20.4% - 47.2% para 13N-azo compuestos). Además, se ha diseñado e implementado un módulo automático con control remoto para el marcaje de moléculas con 13N.
A new strategy for the fast and efficient synthesis of L-[methyl-11C]methionine based on the captive solvent method has been developed. The in loop reaction of a basic water/ethanol 1:1 solution of L-homocysteine with [11C]CH3I led to the formation of the desired radiotracer with high radiochemical yield (38.4 ± 4.1%) in short production time (< 12 min). All analytical parameters were within the specifications of the current version of the Spanish Pharmacopoeia, although specific radioactivity values were relatively low. Thus, the main sources of carbon-12 during the synthesis of [11C]CH3I by the "wet" method were studied and the contribution attributable to each individual source was quantified. The most relevant contamination of non-radioactive CO2 (contribution>90%) was shown to be generated during the bombardment process, probably due to the combustion (caused by high temperature and pressure during irradiation) of carbon carrier compounds present in the irradiated gas (or target body). General procedures to be performed before, during and after the radiosynthesis were established to prevent external contamination and to improve the specific radioactivity of 11C-labeled radiotracers synthesized from [11C]CH3I produced via the "wet" method.
Concerning 13N-labeling, a fully automatic process for the production of [13N]NO2- from cyclotron generated [13N]NO3- has been developed. The radioactive precursor [13N]NO2- has been used for the synthesis of biologically interesting 13N-labeled compounds such as S-nitrosothiols (well-known NO. donors), N-nitrosamines (molecules with potent carcinogenic effects) and azo compounds (with putative application as imaging probes for in vivo detection of β-amyloid plaques). In all cases, excellent radiochemical conversion (48.7% - 74.5% for S-[13N]nitrosothiols, 45.6% - 53.4% for N-[13N]nitrosamines and 40.0% - 58.3% for 13N-labeled azo compounds) and good radiochemical yields (33.8% - 60.6% for S-[13N]nitrosothiols, 34.0% - 37.8% for N-[13N]nitrosamines and 20.4% - 47.2% for 13N-labeled azo compounds) were achieved. An automatic remote controlled synthesis module for the preparation of 13N-labeled structures has been designed and implemented.

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1953-, Wolf-Gladrow Dieter A., ed. COb2s in seawater: Equilibrium, kinetics, isotopes. Amsterdam: Elsevier, 2001.

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Nieuwenhuis, Saskia Apollonia Maria. Investigation of the oxygenic photosynthetic reaction centre photosystem II with specific isotope labelling: Synthesis and incorporation of stable-isotope labelled (S)-phenylalanine and (S)-tyrosine. [Leiden: S.A.M. Nieuwenhuis, 1998.

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Tait, J. C. Validation of the ORIGEN-S code for predicting radionuclide inventories in used CANDU fuel. Pinawa, Man: AECL Research, 1994.

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Rezendes, Victor S. Nuclear science: Status of DOE's self-supporting isotope program : statement by Victor S. Rezendes, Director, Energy Issues, Resources, Community, and Economic Development Division, before the Subcommittee on Environment, Energy, and Natural Resources, Committee on Government Operations, House of Representatives. [Washington, D.C.]: The Office, 1992.

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Habegger, L. J. Update of table S-3 nonradiological environmental parameters for a reference light-water reactor: Uranium mining, milling, and enrichment. Washington, DC: Office of Nuclear Reactor Regulation, U.S. Nuclear Regulatory Commission, 1987.

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The American Medical Isotopes Production Act: Hearing before the Committee on Energy and Natural Resources, United States Senate, One Hundred Twelfth Congress, first session, to receive testimony on S. 99, the American Medical Isotopes Production Act of 2001, February 1, 2011. Washington: U.S. G.P.O., 2011.

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N, Puzankov I͡U︡, Kovalev V. P, and Institut geologii i geofiziki (Akademii͡a︡ nauk SSSR), eds. Radioaktivnye ėlementy i generat͡s︡ii͡a︡ radiogennogo tepla v strukturno-veshchestvennykh kompleksakh Altae-Sai͡a︡nskoĭ oblasti: V svi͡a︡zi s problemami tektoniki. Novosibirsk: Akademii͡a︡ nauk SSSR, In-t geologii i geofiziki, 1989.

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Isotopes in Environmental Studies: Proceedings of an International Conference Held in Monaco 25-29 October 2004 (C&S Papers Series). Intl Atomic Energy Agency, 2006.

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Taylor, Bruce E. "Chapter 7. MAGMATIC VOLATILES: ISOTOPIC VARIATION of C, H, and S." In Stable Isotopes in High Temperature Geological Processes, edited by John W. Valley, Hugh P. Taylor, and James R. O’Neil, 185–226. Berlin, Boston: De Gruyter, 1986. http://dx.doi.org/10.1515/9781501508936-012.

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Savarino, Joël, and Samuel Morin. "The N, O, S Isotopes of Oxy-Anions in Ice Cores and Polar Environments." In Advances in Isotope Geochemistry, 835–64. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-10637-8_39.

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Tomaszek, Janusz A. "Automated Analysis of Stable Isotopes of H, C, N, O and S by Isotope Ratio Mass Spectrometry." In Chemistry for the Protection of the Environment 4, 151–68. Boston, MA: Springer US, 2005. http://dx.doi.org/10.1007/0-387-27448-0_13.

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Dannenmaier, Stefan, Silke Oeljeklaus, and Bettina Warscheid. "2nSILAC for Quantitative of Prototrophic Baker’s Yeast." In Methods in Molecular Biology, 253–70. New York, NY: Springer US, 2021. http://dx.doi.org/10.1007/978-1-0716-1024-4_18.

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AbstractStable isotope labeling by amino acids in cell culture (SILAC) combined with high-resolution mass spectrometry is a quantitative strategy for the comparative analysis of (sub)proteomes. It is based on the metabolicincorporation of stable isotope-coded amino acids during growth of cells or organisms. Here, complete labeling of proteins with the amino acid(s) selected for incorporation needs to be guaranteed to enable accurate quantification on a proteomic scale. Wild-type strains of baker’s yeast (Saccharomyces cerevisiae), which is a widely accepted and well-studied eukaryotic model organism, are generally able to synthesize all amino acids on their own (i.e., prototrophic). To render them amenable to SILAC, auxotrophies are introduced by genetic manipulations. We addressed this limitation by developing a generic strategy for complete “native” labeling of prototrophic S. cerevisiae with isotope-coded arginine and lysine, referred to as “2nSILAC”. It allows for directly using and screening several genome-wide yeast mutant collections that are easily accessible to the scientific community for functional proteomic studies but are based on prototrophic variants of S. cerevisiae.

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Zemlyanoi, S. G., D. V. Karaivanov, Yu P. Gangrsky, K. P. Marinova, B. N. Markov, and J. Badamsambuu. "Hyperfine splitting constants in the optical transition $\boldsymbol{{4{f}^{7}} {6{s}^{2}} \;{^{8}{\rm S}_{7/2}} \to {4{f}^{7}} {6{s}6{p}}\; {^{6}{\rm P}_{5/2}} \ {\rm of} \ {^{151-155}{\rm Eu}}}$ isotopes and hyperfine anomaly." In Laser 2009, 107–13. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-12286-6_11.

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Jayatissa, H., G. V. Rogachev, V. Z. Goldberg, E. Koshchiy, B. T. Roeder, O. Trippella, J. Hooker, et al. "Alpha-Capture Reaction Rate for $$^{22}$$ Ne( $$\alpha $$ , n) via Sub-Coulomb $$\alpha $$ -Transfer and Its Effect on Final Abundances of s-Process Isotopes." In Springer Proceedings in Physics, 377–80. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-13876-9_69.

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Westre, S. G., P. B. Kelly, Y. P. Zhang, and L. D. Ziegler. "Isotopic Dependence of the Methyl-Radical Rydberg 3 s Predissociation Dynamics." In ACS Symposium Series, 297–309. Washington, DC: American Chemical Society, 1992. http://dx.doi.org/10.1021/bk-1992-0502.ch019.

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Kogan, V. M. "Reaction Dynamics during C-S Bond Breaking in Sulphur-Containing Molecules: Isotope Studies." In Transition Metal Sulphides, 235–71. Dordrecht: Springer Netherlands, 1998. http://dx.doi.org/10.1007/978-94-017-3577-3_10.

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Palmerini, Sara, Maurizio Busso, Oscar Trippella, and Diego Vescovi. "s-Processing from MHD-Induced Mixing and Isotopic Abundances in Presolar SiC Grains." In Springer Proceedings in Physics, 201–5. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-13876-9_33.

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Giesemann, A., H. J. Jäger, and K. H. Feger. "Evaluation of sulphur cycling in managed forest stands by means of stable S-isotope analysis." In Nutrient Uptake and Cycling in Forest Ecosystems, 399–404. Dordrecht: Springer Netherlands, 1995. http://dx.doi.org/10.1007/978-94-011-0455-5_46.

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Тези доповідей конференцій з теми "S isotopes"

Bucholz, Claire E., Joseph A. Biasi, Patrick Beaudry, Shuhei Ono, Janne Liebmann, and Christopher J. Spencer. "S Isotopes in Archean & Proterozoic Strongly Peraluminous Granites." In Goldschmidt2020. Geochemical Society, 2020. http://dx.doi.org/10.46427/gold2020.279.

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Theis, Ch, K. Wisshak, K. Guber, F. Voss, F. Käppeler, L. Kazakov, and N. Kornilov. "The s-process cross sections of the tin isotopes." In The 3rd international symposium on nuclear astrophysics: Nuclei in the Cosmos III. AIP, 1995. http://dx.doi.org/10.1063/1.47401.

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Wisshak, K. "Neutron capture in Yb isotopes: Implications for the s-process." In The tenth international symposium on capture gamma-ray spectroscopyand related topics. AIP, 2000. http://dx.doi.org/10.1063/1.1361450.

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Vengosh, Avner, Zhen Wang, Gordon Williams, Robert Hill, Gary Dwyer, Owen Duckworth, Luke Gatiboni, et al. "Strontium isotopes and metal(loid)s variations in global phosphate ores." In Goldschmidt2022. France: European Association of Geochemistry, 2022. http://dx.doi.org/10.46427/gold2022.10558.

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"RADIOACTIVE ISOTOPES OF TOSON-ULA BASIN OF MONGOLIA." In Perspektivnye materialy s ierarkhicheskoy strukturoy dlya novykh tekhnologiy i nadezhnykh konstruktsiy, Khimiya nefti i gaza. Tomsk State University, 2018. http://dx.doi.org/10.17223/9785946217408/384.

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Wisshak, K., F. Voss, and F. Käppeler. "Neutron capture in barium and gadolinium isotopes: Implications for the s-process." In The 3rd international symposium on nuclear astrophysics: Nuclei in the Cosmos III. AIP, 1995. http://dx.doi.org/10.1063/1.47428.

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Domingo-Pardo, Cesar, U. Abbondanno, G. Aerts, H. Álvarez-Pol, F. Alvarez-Velarde, S. Andriamonje, J. Andrzejewski, et al. "Neutron capture measurements on the s-process termination isotopes lead and bismuth." In International Symposium on Nuclear Astrophysics - Nuclei in the Cosmos - IX. Trieste, Italy: Sissa Medialab, 2010. http://dx.doi.org/10.22323/1.028.0058.

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Dal Corso, Jacopo, Robert J. Newton, Daoliang Chu, Paul B. Wignall, Aubrey L. Zerkle, Mark Claire, Tommaso Di Rocco, et al. "Multiple S Isotopes and Hg Geochemistry at the Terrestrial Permo-Triassic Mass Extinction." In Goldschmidt2020. Geochemical Society, 2020. http://dx.doi.org/10.46427/gold2020.514.

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Khan, Muhammad, Marc Litz, Johnny Russo, and Randy Tompkins. "Alpha-Photovoltaics for Milliwatt Applications." In ASME 2022 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/detc2022-91306.

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Abstract Isotope power sources can serve applications for sensor or communication nodes that are required to last the lifetime of infrastructure because they possess at least 1000 times higher energy density, long operational lifetimes (> 10 years), and wider operational temperature range compared to chemical power sources. There are different methods of converting radiation energy into electrical energy at low power (nW – mW) levels, the most prevalent is betavoltaic devices which convert beta particles energy directly into electrical energy using a semiconductor junction. However, the current state-of-the art betavoltaics can only produce 10’s of micro-watts/cm2, and are not suitable for applications requiring mW output power. Alpha particle emitting isotopes have higher energies than beta isotopes and can be used to produce power in mW range, but require radiation tolerant ultra-wide-bandgap semiconductor junctions, which are not widely available yet. Therefore, it is necessary to look at alternate approaches to harvest energy from alpha decay using existing semiconductor technology. In this paper, we have validated one such approach to convert alpha particles energy into electrical energy by employing an intermediate phosphor layer placed between an alpha source and an InGaP PV cell. We simulated the average energy emission of Am-241 using a pelletron source accelerating He2+ ions and exposed the InGaP PV with phosphor film deposited on top while measuring the IV characteristics throughout the experiment. We measured an output power of 165 μW/cm2 at 4.5 MeV beam, representing a fluence of 3.75 × 1013 ions.

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Lederer, Claudia. "Neutron-induced reactions for the s-process, and the case of Fe and Ni isotopes." In XII International Symposium on Nuclei in the Cosmos. Trieste, Italy: Sissa Medialab, 2013. http://dx.doi.org/10.22323/1.146.0023.

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Звіти організацій з теми "S isotopes"

Kidder, J. A., M. B. McClenaghan, M I Leybourne, M. W. McCurdy, P. Pelchat, D. Layton-Matthews, C. E. Beckett-Brown, and A. Voinot. Geochemical data for stream and groundwaters around the Casino Cu-Au-Mo porphyry deposit, Yukon (NTS 115 J/10 and 115 J/15). Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/328862.

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This open file reports geochemical data for stream and groundwater samples collected around the Casino porphyry Cu-Au-Mo deposit, one of the largest and highest-grade deposits of its kind in Canada. The calc-alkaline porphyry is hosted in a Late Cretaceous quartz monzonite and associated breccias in the unglaciated region of west central Yukon. Water chemistry around the deposit was investigated because: (i) the deposit has not yet been disturbed by mining; (ii) the deposit was known to have metal-rich waters in local streams; and (iii) the deposit has atypically preserved ore zones. Stream water samples were collected at 22 sites and groundwater samples were collected from eight sites. Surface and groundwaters around the Casino deposit are anomalous with respect to Cd (up to 5.4 µg/L), Co (up to 64 µg/L), Cu (up to 1657 µg/L), Mo (up to 25 µg/L), As (up to 17 µg/L), Re (up to 0.7 µg/L), and Zn (up to 354 µg/L) concentrations. The stable isotopes of O and H of the groundwaters are essentially identical to the surface waters and plot close to the local and global meteoric water lines, indicating that the waters represent modern recharge, consistent with the generally low salinities of all the waters (total dissolved solids range from 98 to 1320 mg/L). Sulfur and Sr isotopes are consistent with proximal waters interacting with the Casino rocks and mineralization; a sulfide-rich bedrock sample from the deposit has delta-34S = -1.2 permille and proximal groundwaters are only slightly heavier (-0.3 to 3.1 permille). These geochemical and isotopic results indicate that surface water geochemistry is a suitable medium for mineral exploration for porphyry-style mineralization in the Yukon, and similar unglaciated regions in Canada. The atypical geochemical signature (Mo, Se, Re, As, Cu) of these types of deposits are typically reflected in the water chemistry and S isotopes provide a more local vectoring tool.

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Davisson, M. L., G. B. Hudson, S. Niemeyer, J. Beiriger, and R. Herndon. Report on the feasibility of using isotopes to source and age-date groundwater in Orange County water district`s Forebay region. Office of Scientific and Technical Information (OSTI), May 1996. http://dx.doi.org/10.2172/266844.

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Hiebert, R. S., A. Bekker, M. G. Houlé, O. J. Rouxel, and B. A. Wing. Identifying and tracing crustal contamination in the Hart komatiite-associated Ni-Cu-(PGE) deposit using multiple S and Fe isotopes: Abitibi greenstone belt, Ontario. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 2015. http://dx.doi.org/10.4095/296690.

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Eckstrand, O. R., L. N. Grinenko, H. R. Krouse, A. D. Paktunc, P L Schwann, and R. F. J. Scoates. Preliminary Data On Sulphur Isotopes and Se/S Ratios, and the Source of Sulphur in Magmatic Sulphides From the Fox River Sill, Molson Dykes and Thompson Nickel Deposits, northern Manitoba. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 1989. http://dx.doi.org/10.4095/126860.

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Cesar, J. R., and O. H. Ardakani. Organic geochemistry of the Montney Formation: new insights about the source of hydrocarbons, their accumulation history and post accumulation processes. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/329788.

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This study consists of a non-traditional molecular and stable isotope approach to analyze organic matter (soluble bitumen and produced oil/condensate) from the Montney Formation low-permeability reservoirs, with the purpose of identifying source(s) of hydrocarbons, accumulation history and post accumulation processes. The same approach bases on the distribution of compound classes such as aromatic carotenoids, polycyclic aromatic hydrocarbons (PAHs), bicyclic alkanes, and oxygen-polar compounds. The geochemical screening has been enhanced with performing compound specific isotope analysis (CSIA) of n-alkanes and selected aromatic hydrocarbons. Widely spread PAHs, the presence of molecular indicators of euxinia, and hydrocarbon mixtures identified using CSIA profiles, are some of the key findings from this research, which will improve our understanding of the Montney petroleum system(s).

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Smith, D. H., and H. S. McKown. New FORTRAN computer programs to acquire and process isotopic mass spectrometric data: Operator`s manual. Office of Scientific and Technical Information (OSTI), September 1993. http://dx.doi.org/10.2172/10194933.

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Taylor, D. Isotope identification as a part of the decommissioning of San Diego State University`s Texas Nuclear neutron generator. Office of Scientific and Technical Information (OSTI), July 1997. http://dx.doi.org/10.2172/671980.

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B. Peterman and R. Moscati. Calcite Fluid Inclusion, Paragenetic, and Oxygen Isotopic Records of Thermal Event(s) at Yucca Mountain, Nevada. Office of Scientific and Technical Information (OSTI), August 2000. http://dx.doi.org/10.2172/840694.

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Gadd, M., D. Layton-Matthews, J. Peter, and S. Paradis. Trace element characteristics and S isotopic compositions of pyrite in the Howard's Pass Zn-Pb district, Selwyn Basin, Yukon. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 2014. http://dx.doi.org/10.4095/293468.

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Gadd, M. G., J. M. Peter, and D. Layton-Matthews. Genesis of hyper-enriched black shale Ni-Mo-Zn-Pt-Pd-Re mineralization in the northern Canadian Cordillera. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/328013.

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Polymetallic (Ni-Mo-Zn-Pt-Pd-Au-Re) hyper-enriched black shales in the northern Canadian Cordillera consist of thin, semi-massive sulfides interbedded with black shale. We studied HEBS deposits at Nick, Peel River, Monster River, and Moss in northern Yukon, and at a single locality underlying the Cardiac Creek Pb-Zn-Ag deposit in northeastern British Columbia. High-grade mineralization contains up to 7.4 weight per cent Ni, 2.7 weight per cent Zn, 0.38 weight per cent Mo, 400 ppb Pt, 250 ppb Pd, 160 ppb Au, and 58.5 ppm Re. Sulfide mineralization formed during syngenesis to later diagenesis. Analyses by LA-ICP-MS indicate that pyrite is the principal host of platinum-group elements, Au, and Re. Mineralization and sedimentation were coeval based on the overlap between Re-Os geochronology of HEBS at Nick and Peel River (390.7 ± 5.1 and 387.3 ± 4.4 Ma, respectively) and conodont biostratigraphic ages of sedimentary host rocks. Bulk S isotope composition of HEBS is uniformly negative, indicating that bacterial reduction of seawater sulfate generated sulfur to precipitate sulfide minerals. The initial Os ratios at Peel River (0.25 ± 0.07) and Nick (0.32 ± 0.20) overlap with Middle Devonian seawater, suggesting that elemental enrichment was derived from seawater.

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