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Dissertations / Theses on the topic 'Isotopes'

Author: Grafiati

Published: 4 June 2021

Last updated: 25 July 2025

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1

Nilsson, Lino. "Nitrogen transformations at the Kiruna mine : The use of stable nitrogen isotopes to trace nitrogen-transforming processes." Thesis, Uppsala universitet, Luft-, vatten och landskapslära, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-209419.

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Release of different nitrogen compounds can cause eutrophication in lakes and rivers whichcan lead to oxygen-free environments in bottom water and in the sediment and can in turnlead to fish-deaths. Ammonium can be toxic to biota and nitrate can in high concentrationeven be toxic to humans. WHO has released a limit for nitrate concentration in drinking waterof 10mg/l. The LKAB mine in Kiruna is the largest underground iron mine in the world and isprospecting, mining and refining iron ore, with an annual production of around 28 milliontons. Release of different nitrogen compounds as a result of

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2

Dubeau, Jacques. "Isotope shift measurements of the stable krypton isotopes in natural and enriched concentrations." Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=66154.

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3

Vaiglova, Petra. "Neolithic agricultural management in the Eastern Mediterranean : new insight from a multi-isotope approach." Thesis, University of Oxford, 2016. https://ora.ox.ac.uk/objects/uuid:c8824136-da35-43b2-a700-f458d0cc2fdf.

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The work presented in this dissertation explores the nature of agro-pastoral strategies developed by Neolithic farmers as a way to understand how early food production was inter-twined with environmental and socio-economic opportunities and constraints. Towards this end, a multi-isotope approach is used to address questions of scale and intensity of crop cultivation and animal management at the archaeological sites of Kouphovouno, southern Greece, Makriyalos, northern Greece, and Çatalhöyük, south-central Turkey. Measurements of stable carbon, nitrogen, oxygen and strontium isotope values o

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4

Móri, Cleusa [UNESP]. "Rastreabilidade de farinhas de origem animal em tecidos de codornas de corte pela técnica dos isótopos estáveis de carbono ('intpot.13C'/'intpot.12C') e nitrogênio ('intpot.15N'/'intpot.14N')." Universidade Estadual Paulista (UNESP), 2007. http://hdl.handle.net/11449/104988.

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Made available in DSpace on 2014-06-11T19:33:34Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-05Bitstream added on 2014-06-13T18:45:25Z : No. of bitstreams: 1 mori_c_dr_botfmvz.pdf: 326000 bytes, checksum: 0ec30e51a3d43636409c064480add1c6 (MD5)<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)<br>Universidade Estadual Paulista (UNESP)<br>Estudos para detecção de subprodutos de origem animal em carne de aves são escassos e, em se tratando de codornas são inexistentes. O trabalho teve por objetivo a detecção de farinha de vísceras de aves (FVA) em dietas de codorn

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5

Móri, Cleusa 1974. "Rastreabilidade de farinhas de origem animal em tecidos de codornas de corte pela técnica dos isótopos estáveis de carbono ('intpot.13C'/'intpot.12C') e nitrogênio ('intpot.15N'/'intpot.14N') /." Botucatu : [s.n.], 2007. http://hdl.handle.net/11449/104988.

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Orientador: Edivaldo Antônio Garcia<br>Banca: Ricardo de Albuquerque<br>Banca: Carla Cachoni Pizzolante<br>Banca: Carlos Ducatti<br>Banca: Ariel Antonio Mendes<br>Resumo: Estudos para detecção de subprodutos de origem animal em carne de aves são escassos e, em se tratando de codornas são inexistentes. O trabalho teve por objetivo a detecção de farinha de vísceras de aves (FVA) em dietas de codornas de corte no músculo peitoral quilha e tíbia pela técnica dos isótopos estáveis de carbono (13C/12C) e nitrogênio (15N/14N). Foram utilizadas 64 codornas de corte macho de um dia de idade advindas de

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6

Petitat, Manuel. "Cr isotopes in carbonaceous chondrites : 53Mn-53Cr systematics and Cr isotopic anomalies." Paris, Muséum national d'histoire naturelle, 2010. http://www.theses.fr/2010MNHN0017.

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Cette thèse comporte deux parties distinctes. Dans la première partie, la systématique 53Mn-53Cr a été développée sur une NanoSIMS 50 et une CAMECA IMS 1270 pour dater la formation de carbonates dans les météorites Orgueil, Alais, Boriskino et Kaidun. Dans chaque grain, les excès en 53Cr mesurés corrèlent linéairement avec leurs rapports élémentaires 55Mn/52Cr ratios mesurés, indiquant la décroissance in-situ de 53Mn et donc la présence de 53Mn lorsque le grain a cristallisé. Dans la deuxième partie, un fragment de Tagish Lake et d’Orgueil ont été dissouts en 5 étapes afin d’identifier les pha

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7

Perez, Fernandez Andrea. "Etude expérimentale sur l'échange isotopique dans le système eau-roches carbonatées." Thesis, Toulouse 3, 2017. http://www.theses.fr/2017TOU30398.

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Les signatures isotopiques des minéraux carbonatés sont utilisées pour caractériser de nombreux processus géochimiques. Cette thèse a pour but de déterminer les vitesses auxquelles ces signatures isotopiques peuvent être altérées lors des interactions entre les fluides et les minéraux. A cette fin, une série d'études expérimentales a été conduite avec la dolomite (CaMg(CO3)2), la magnésite (MgCO3) et la calcite (CaCO3). On a mesuré l'évolution temporelle des compositions isotopiques de Ca et Mg pendant une série d'expériences de dissolution en réacteur fermé de la dolomite à des températures d

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8

Suzuki, Rafael Massami. "Aminoácidos marcados aplicados aos estudos de nutrição e fisiologia em frangos de corte /." Jaboticabal, 2019. http://hdl.handle.net/11449/191289.

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Orientador: Nilva Kazue Sakomura<br>Resumo: RESUMO: A evolução das análises, considerando especificamente a nutrição e fisiologia de frangos de corte, permitiram rastrear nutrientes a níveis nucleares, permitindo que novas metodologias fossem desenvolvidas e novos objetivos alcançados. Algumas das análises que merecem destaque considerando estudos voltados a exigências de aminoácidos e metabolismo proteico foram: determinação de nitrogênio total/proteína, análise da composição aminoacídica e análise isotópica, sendo que a associação destas análises permite um potencial ainda maior. O uso de co

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9

Swift, Benjamin. "The use of radio-isotopes in forensic science : the development of the isotope fingerprint analysis." Thesis, University of Leicester, 2004. http://hdl.handle.net/2381/29475.

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It is generally accepted that remains should be no more than 75 years old to warrant police interest. Therefore any reliable dating method should distinguish bones from within this interval accurately from those lying outside of it. Although archaeologists have reliable tools for dating material, pathologists have been unable to devise a method that caters for their specific needs. Previous work has focused upon the physiochemical properties of bone or its organic constituents, though the results have failed to produce a workable calibration system. The first hypothesis of this thesis has conf

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10

Huckle, David Martyn. "Characterizing U-series Isotope Signatures in Soils and Headwater Streams in a Complex Volcanic Terrain: Jemez River Critical Zone Observatory, Valles Caldera, NM." Thesis, The University of Arizona, 2013. http://hdl.handle.net/10150/305863.

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Uranium-series isotopes are an emerging tool to characterize weathering and soil forming processes in the Critical Zone, the dynamic region of earth's surface where bedrock, water, soil, and life chemically and physically interact to support ecosystems. Understanding controls on the U-series composition of soils across a range of lithologies and climate is critical to applying existing mass balance models of U-series isotopes to calculate soil formation rates in these systems. This study seeks to understand the behavior of U-series isotopes in soil profiles in the semi-arid complex volcanic

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11

Jones, Charles Edward. "Strontium isotopes in Jurassic and Early Cretaceous seawater." Thesis, University of Oxford, 1992. http://ora.ox.ac.uk/objects/uuid:fe3733bd-8e31-4bba-a78b-6d8275a0075f.

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The collection and analysis of a large number of belemnites and oysters with excellent biostratigraphic and diagenetic control has resulted in a highly detailed determination of the seawater Sr-isotope curve through the Jurassic and Early Cretaceous. The new data confirm the broad trends established by previous work, but the much sharper resolution of the new data allows the application of Sr-isotope stratigraphy with an optimal stratigraphic resolution of ± 1 to 4 ammonite subzones (± 0.5 to 2 Ma). The data show a general decline from the Hettangian (Early Jurassic) to a minimum in the Callov

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12

Churchill, Layne Russell. "Trapping triply ionized thorium isotopes." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/37161.

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Cold trapped ions have many applications in quantum information science and precision metrology. In this thesis, we present progress toward two objectives involving ions confined to linear RF traps: the strong coupling of Ba+ ions with a high finesse optical cavity, and the observation of an optical nuclear transition in 229Th3+. In pursuit of the first objective, a novel high-temperture vapor cell for the spectroscopy of neutral barium was constructed. Using this vapor cell, a new technique for isotope-selective photoionization loading of Ba+ in an ion trap was developed. In pursuit of t

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13

Brown, S. A. "Condition monitoring using stable isotopes." Thesis, Imperial College London, 1987. http://hdl.handle.net/10044/1/38246.

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14

Babikov, Mark. "Alternative Algebras and Their Isotopes /." The Ohio State University, 1996. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487933245539266.

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15

Jentoft-Nilsen, Kristi Lynette. "Deformation and the search for shape coexistence in odd-mass neutron-deficient iridium isotopes : studies of the B+/EC-decay of ¹⁸³Pt and ¹⁸¹Pt." Diss., Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/29447.

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16

Semmes, Paul Barksdale. "Core-quasiparticle coupling model calculations as a test of IBA core descriptions of the even-mass Hg isotopes : decay of mass-separated [superscript]203At." Diss., Georgia Institute of Technology, 1985. http://hdl.handle.net/1853/30906.

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17

Lowles, Ian Michael. "Decay scheme data of neptunium isotopes." Thesis, Imperial College London, 1991. http://hdl.handle.net/10044/1/46897.

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18

Buesseler, Ken O. "Plutonium isotopes in the North Atlantic." Online version, 1986. http://hdl.handle.net/1912/3484.

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19

Audet, Daniel. "Spectroscopie de polarisation : isotopes du krypton." Thesis, McGill University, 1985. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=63319.

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20

England, J. G. "Laser resonance spectroscopy of samarium isotopes." Thesis, University of Manchester, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.374792.

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21

Buesseleer, Ken O. "Plutonium isotopes in the North Atlantic." Thesis, Massachusetts Institute of Technology, 1986. http://hdl.handle.net/1721.1/55309.

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Thesis (Ph. D.)--Joint Program in Oceanography (Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), 1986.<br>Microfiche copy available in Archives and Science.<br>Vita. Chapter 5: ²³⁹,̳²⁴⁰Pu and excess ²¹⁰Pb inventories along the shelf and slope of the northeast U.S.A. / Ken O. Buesseler, Hugh D. Livingston and Edward R. Sholkovitz, reprinted from Earth and Planetary Science Letters, 76 (1985/86) 10-22, Elsevier Science Publishers, B. V. Amsterdam. The underscored comma in the above note is superscript on th

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22

Moos, Simone Beatrice. "The marine biogeochemistry of chromium isotopes." Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/115788.

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Thesis: Ph. D., Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), 2018.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references.<br>In the ocean, chromium (Cr) is a redox-sensitive trace metal. The reduction of Cr(VI) to Cr(III) occurs in oxygen deficient zones (ODZs), and Cr reduction in general has been identified as a significant Cr isotope fractionation mechanism. This thesis presents the first Cr isotope

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23

John, Seth G. "The marine biogeochemistry of zinc isotopes." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/40968.

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Thesis (Ph. D.)--Joint Program in Chemical Oceanography (Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), 2007.<br>Includes bibliographical references.<br>Zinc (Zn) stable isotopes can record information about important oceanographic processes. This thesis presents data on Zn isotopes in anthropogenic materials, hydrothermal fluids and minerals, cultured marine phytoplankton, natural plankton, and seawater. By measuring Zn isotopes in a diverse array of marine samples, we hope to understand how Zn isotope

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24

Vogl, Gero, Marcus Rennhofer, Bogdan Sepiol, Manfred Smolik, Franz Essl, and Ingrid Kleinbauer. "Invasions of isotopes and of neobiota." Universitätsbibliothek Leipzig, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-194174.

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We report on invasions with low diffusivity: one in materials science and one in ecology. What is interesting in materials science is to describe diffusivities in order to model technological important materials. In ecology on the other hand predictions into the future appear the most challenging issue.

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25

Glowa, Dominika Aleksandra. "Neutron skin measurement of tin isotopes." Thesis, University of Edinburgh, 2016. http://hdl.handle.net/1842/20451.

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Heavy atomic nuclei are thought to have proton and neutron radial distributions which have different extents. This difference is usually quantified in terms of a neutron skin (rnp), defined as the difference between the root mean square radii of the neutron and proton radial distributions (rnp = rn - rp). The nature, or even existence, of the neutron skin is currently not well established for many nuclei. Different nuclear theories give different predictions for the neutron skin thickness ranging for a typical heavy nucleus from 0.05 to 0.35 fm. Accurate measurement of the properties of the ne

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26

Vogl, Gero, Marcus Rennhofer, Bogdan Sepiol, Manfred Smolik, Franz Essl, and Ingrid Kleinbauer. "Invasions of isotopes and of neobiota." Diffusion fundamentals 6 (2007) 76, S. 1-2, 2007. https://ul.qucosa.de/id/qucosa%3A14256.

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We report on invasions with low diffusivity: one in materials science and one in ecology. What is interesting in materials science is to describe diffusivities in order to model technological important materials. In ecology on the other hand predictions into the future appear the most challenging issue.

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27

Gengelbach, Aila. "Collectivity in Neutron-Rich Erbium Isotopes." Licentiate thesis, Uppsala universitet, Kärnfysik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-442208.

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Neutron-rich rare-earth nuclei around the maximum of collectivity are predicted to exist with an extremely stable intrinsic configuration in their ground-state structure. Due to the high degree of axial symmetry and large deformation, these nuclei are also excellent candidates for having long-lived high-K isomers. The present work concerns a study of the structure of the yrast bands and a search for isomers in the neutron-rich 68Er isotopes. Excited states of 68Er isotopes were populated via multi-nucleon transfer reactions. A 859 MeV 136Xe-beam was used to bombard a 170Er-target. The experime

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PORZIO, CARLOTTA. "CONFIGURATION MIXING INVESTIGATION IN GERMANIUM ISOTOPES." Doctoral thesis, Università degli Studi di Milano, 2021. http://hdl.handle.net/2434/886195.

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Protons and neutrons of atomic nuclei can arrange in both spherical and non-spherical configurations. Nuclei can also exhibit configurations which lie close in energy, yet present different deformations. Such phenomenon is referred to as shape coexistence and its occurrence in nuclei is thought to pervade the entire nuclear chart. Excited states with similar energies and same spin and parity can also mix, so that the observed states are the result of mixing of different configurations. In this context, the structure of Ge isotopes has been widely investigated over the years. Previous transfer

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Bordinhon, André Moreira [UNESP]. "Autobalanceamento da energia e da proteína da dieta pela tilápia do Nilo por meio de isótopos estáveis de carbono e do consumo de matéria seca." Universidade Estadual Paulista (UNESP), 2008. http://hdl.handle.net/11449/104115.

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Made available in DSpace on 2014-06-11T19:32:58Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-03-07Bitstream added on 2014-06-13T20:24:29Z : No. of bitstreams: 1 bordinhon_am_dr_botfmvz.pdf: 349449 bytes, checksum: 88ef6cffe52ded03eb9ff128cda0f865 (MD5)<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)<br>Universidade Estadual Paulista (UNESP)<br>O objetivo deste trabalho foi avaliar a capacidade da tilápia do Nilo em 5 balancear sua dieta, quando fornecidas duas misturas de ingredientes, utilizando os 6 isótopos estáveis de carbono. Foram utilizados 225 juvenis

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Bueno, Juliana Finoto. "Geoquimica e cronologia de alojamento de granitos colisionais na Faixa Sergipana, Nordeste do Brasil." [s.n.], 2008. http://repositorio.unicamp.br/jspui/handle/REPOSIP/287312.

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Orientador: Elson Paiva de Oliveira<br>Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Geociencias<br>Made available in DSpace on 2018-08-12T17:14:03Z (GMT). No. of bitstreams: 1 Bueno_JulianaFinoto_D.pdf: 33760370 bytes, checksum: 4d0399db10bb1617f66de0162048b7fe (MD5) Previous issue date: 2008<br>Resumo: A Faixa Sergipana é uma das mais significantes faixas móveis neoproterozóicas do nordeste do Brasil, porque ela contém diversas estruturas e domínios litológicos que permitem que ela seja comparada a orógenos fanerozóicos como os Himalaias, por exemplo. A Faixa Sergipana

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Bordinhon, André Moreira 1978. "Autobalanceamento da energia e da proteína da dieta pela tilápia do Nilo por meio de isótopos estáveis de carbono e do consumo de matéria seca /." Botucatu : [s.n.], 2008. http://hdl.handle.net/11449/104115.

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Orientador: Luiz Edivaldo Pezzato<br>Banca: Wilson Massamitu Furuya<br>Banca: José Fernando Machado Menten<br>Banca: Carlos Ducatti<br>Banca: José Roberto Sartori<br>Resumo: O objetivo deste trabalho foi avaliar a capacidade da tilápia do Nilo em 5 balancear sua dieta, quando fornecidas duas misturas de ingredientes, utilizando os 6 isótopos estáveis de carbono. Foram utilizados 225 juvenis de tilápia (peso: 5,0 ± 0,5 g), 7 distribuídos em cinco tanques. Os indivíduos alocados em um dos tanques eram 8 alimentados com uma mistura de alta proteína (MAP; δ13C = -22,62‰), os alocados em 9 um segun

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Costa, Gelcirene de Albuquerque [UNESP]. "Rastreabilidade de camarão amazônico proveniente de cultivo e ambiente natural utilizando a técnica de isótopos estáveis." Universidade Estadual Paulista (UNESP), 2013. http://hdl.handle.net/11449/86669.

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Made available in DSpace on 2014-06-11T19:22:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-02-27Bitstream added on 2014-06-13T19:07:45Z : No. of bitstreams: 1 costa_ga_me_jabo.pdf: 398423 bytes, checksum: bc07b3e5f98d29910cf30e3b83eff7eb (MD5)<br>A globalização no comércio de pescado tem aumentado à oferta do produto, mas tem favorecido a prática de fraudes, como por exemplo, a substituição de espécies nobres por espécies de menor valor comercial. Por outro lado, consumidores cada vez mais exigentes têm demonstrado preferências por produtos de sistemas agroalimentares diferenciad

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Costa, Gelcirene de Albuquerque. "Rastreabilidade de camarão amazônico proveniente de cultivo e ambiente natural utilizando a técnica de isótopos estáveis /." Jaboticabal, 2013. http://hdl.handle.net/11449/86669.

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Orientador: Léa Silvia Sant'Ana<br>Banca: Juliana Célia Denadai<br>Banca: Maria Márcia Pereira Sartori<br>Resumo: A globalização no comércio de pescado tem aumentado à oferta do produto, mas tem favorecido a prática de fraudes, como por exemplo, a substituição de espécies nobres por espécies de menor valor comercial. Por outro lado, consumidores cada vez mais exigentes têm demonstrado preferências por produtos de sistemas agroalimentares diferenciados. No Brasil, a regulamentação para as indicações geográficas tem crescido em ritmo acelerado nos últimos dois anos, exigindo o desenvolvimento de

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Brito, Adriano Leal de. "Oxigênio-18 e deutério traçadores do sistema de aqüíferos na Bacia Sedimentar do Araripe." reponame:Repositório Institucional da UFC, 2012. http://www.repositorio.ufc.br/handle/riufc/13703.

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BRITO, Adriano Leal de. Oxigênio-18 e deutério traçadores do sistema de aqüíferos na Bacia Sedimentar do Araripe. 2012. 96 f. Dissertação (Mestrado em Física) - Programa de Pós-Graduação em Física, Departamento de Física, Centro de Ciências, Universidade Federal do Ceará, Fortaleza, 2012.<br>Submitted by Edvander Pires (edvanderpires@gmail.com) on 2015-10-21T21:30:43Z No. of bitstreams: 1 2012_dis_albrito.pdf: 1763548 bytes, checksum: 4fe45ca63d81b9f56baf5d804acb37a4 (MD5)<br>Approved for entry into archive by Edvander Pires(edvanderpires@gmail.com) on 2015-10-22T21:31:50Z (GMT) No. of bitstre

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Vega, Leticia. "La expansión de los desiertos andinos en latitudes medias de América del Sur ˸ Una aproximación paleoclimática." Electronic Thesis or Diss., université Paris-Saclay, 2025. http://www.theses.fr/2025UPASJ006.

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Les changements environnementaux tels que les sécheresses plus fréquentes et plus sévères, résultant de facteurs anthropiques, naturels ou combinés, ont été enregistrés dans toute la région andine tempérée d'Amérique du Sud. La disponibilité de l'eau est cruciale pour le fonctionnement des écosystèmes, des sociétés et des économies de cette région. Cependant, le manque d'observations climatiques à long terme complique la contextualisation de ces changements et génère de l'incertitude quant à la nouvelle normalité climatique à l'avenir.La variabilité climatique dans la région andine tempérée es

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Goedert, Jean. "Écologie des premiers tétrapodes dévoilée par la composition isotopique du soufre (34S/32S) de leurs squelettes." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSE1337.

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La dichotomie environnementale qui caractérise la Terre, à savoir la présence de milieux aquatiques et de terres émergées, a joué un rôle important au cours de l’évolution de la vie. L’histoire évolutive des vertébrés, par exemple, a continuellement été ponctuée d’épisodes de sorties des eaux et de retours aux milieux aquatiques, souvent soulignés dans le registre fossile par des radiations biologiques majeures. L’exemple le plus célèbre concerne probablement les épisodes de sorties des eaux des premiers tétrapodes qui bouleversent les écosystèmes terrestres il y a environ 360 millions d’année

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Cruz, Steffen James. "Single particle structure of exotic strontium isotopes." Thesis, University of British Columbia, 2017. http://hdl.handle.net/2429/61928.

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The sudden onset of ground state deformation and the emergence of shape-coexisting states in the vicinity of N~60 and Z~40 has been a subject of substantial interest for many years. It has been shown that the emergence of deformed low-energy configurations can be explained in the shell model by the evolution of single particle structure and the interaction between protons and neutrons in certain valence orbitals. However, the numerous theoretical models that have been developed for this transitional region are limited by the experimental data that is available. In particular, a description of

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Lhomme, Nicolas. "Modelling water isotopes in polar ice sheets." Thesis, Université Joseph Fourier (Grenoble), 2004. http://hdl.handle.net/2429/17134.

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Concentrations of water isotopes in marine sediments and ice cores are a key indicator for estimating global and regional fluctuations of past temperatures. Interpreting these concentrations requires an understanding of the storage capacity and exchanges among the ocean, atmosphere and cryosphere as well as an understanding of the dynamical behaviour of these reservoirs. The contribution of the latter remains poorly established because of the paucity of deep ice cores in Greenland and Antarctica and the difficulty of interpreting these cores. To obtain the water isotope composition of po

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Gallagher, Andrew James. "Modelling barium isotopes in metal-poor stars." Thesis, University of Hertfordshire, 2012. http://hdl.handle.net/2299/9224.

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The principal theory concerning the origin of the elements heavier than the Fe-peak, such as Ba, strongly suggest that for old, metal-poor environments, the rapid (r-) process is the most likely path taken in their synthesis, while the slow (s-) process becomes more substantial in younger, more metal-rich stellar populations. In this work I test this theory by evaluating the isotope ratios of Ba. It is understood that Ba consists of seven stable isotopes, five of which are synthesised by the two neutron-capture processes. The two odd isotopes, 135,137Ba, as well as 138Ba are synthesised via bo

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Chapman, John Branson. "Iron isotopes in hydrothermal ore-forming systems." Thesis, Imperial College London, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.582584.

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Column chemistry element purification methods were optimised for separation of Cu, Fe and Zn from geological samples taken from hydrothermal ore-forming systems. The method presented produces high-purity elemental separates at -100% recovery, ensuring absence of column-induced isotopic fractionation. Variation of Fe isotope ratios within two different mineral deposit types was investigated. In the West Cumbrian hematite, isotopic variability due to intermineral, redox and biological fractionation is likely absent, allowing identification of fluid flow and mineral precipitation effects. Isotopi

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Chael, Bradley. "Laser spectroscopy of cerium and yttrium isotopes." Thesis, University of Birmingham, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.422322.

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Thayer, Hazel Louise. "Collinear laser spectroscopy of radioactive zirconium isotopes." Thesis, University of Birmingham, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.398683.

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Fawcett, M. J. "High sensitivity collinear spectroscopy on strontium isotopes." Thesis, University of Manchester, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.233278.

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Miller, Christian Alexander. "Surface-cycling of rhenium and its isotopes." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/53548.

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Thesis (Ph. D.)--Joint Program in Chemical Oceanography (Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), 2009.<br>Includes bibliographical references.<br>The application of elemental and isotopic metal palaeoredox tracers to the geologic past rests on an understanding of modern metal cycles. This study reevaluates the surface-cycling of Mo and Re in near-surface reservoirs. Revised river averages of Mo and Re are 1.8- and 7.9-fold larger than previous estimates. The river concentrations of 8.0 nmol Mo kg

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Valdes, Maria. "Geochemistry and Cosmochemistry of Calcium Stable Isotopes." Doctoral thesis, Universite Libre de Bruxelles, 2018. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/276866.

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Calcium (Ca) is the fifth most abundant element in the rocky planets. As a lithophile, refractory element, Ca does not partition into planetary cores nor is it volatilized during planetary accretion. These characteristics make Ca ideal for investigating the earliest stages of planetary formation and the subsequent chemical evolution of planetary mantles and crusts. This thesis presents observations of and explores the mechanisms involved in high-temperature mass-dependent Ca isotope fractionation in terrestrial, lunar, and meteoritic material. Chapter 1 reports Ca isotope fractionation among a

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Nigron, Etienne. "Isotopes radioactifs produits par voies non conventionnelles." Thesis, Nantes, 2019. http://www.theses.fr/2019NANT4032.

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La médecine nucléaire utilise des radionucléides pour le diagnostic et pour la thérapie. La tendance suivie par la médecine nucléaire est de s'adapter de plus en plus à chaque patient. Pour arriver à cet objectif, une large gamme de radionucléides doit être disponible pour répondre aux besoins des médecins. Une approche théranostique (thérapie et diagnostic) peut être mise en place dès la conception du médicament permettant d'orienter la médecine vers une médecine personnalisée. Dans cette optique, des études de production de radionucléides innovants par voies non conventionnelles (faisceaux d

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Varhelyi, Aron. "Quaternary Arctic foraminiferal isotopes: species reliability and palaeoceanographic application." Thesis, Stockholms universitet, Institutionen för geologiska vetenskaper, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-158047.

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To investigate whether foraminiferal stable isotope (δ18O/δ13C) variations have potential as a chronostratigraphic tool in the Arctic Ocean, this thesis presents new δ18O/δ13C data from five marine sediment cores. Three of those are downcore analyses (PS92/54-1; TC/PC-03; PC-07) and the remaining two are core top analyses (PC-04; PC-08). Seven species of benthic foraminifera (Cassidulina neoteretis, Cibicides lobatulus, Cibicidoides wuellerstorfi, Oridorsalis tener, Quinqueloculina arctica, Stainforthia concava and Triloculina sp.) and one planktic (Neogloboquadrina pachyderma sinistral) were

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Brown, Daniel Edward. "Low temperature nuclear orientation studies of nuclei far from stability." Thesis, University of Oxford, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.257942.

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Ritz, P. "An appraisal of the doubly labelled water method for energy expenditure measurements." Thesis, University of Cambridge, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.319821.

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Hannachi, Fazia. "Étude des isotopes de mercure de la région de transition A ~ 186." Paris 11, 1987. http://www.theses.fr/1987PA112475.

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Les états de haut spin des noyaux ¹⁸⁵,¹⁸⁷,¹⁸⁸Hg produits dans les réactions ¹⁶¹,¹⁶³,¹⁶⁴Dy (²⁸Si (135-151 MeV, xn) ont été étudiés à l’aide d’un multidétecteur 4π « Château de Cristal » en ligne sur le tandem du C. R. N. Strasbourg. Des mesures de distribution angulaire, de polarisation linéaire des transitions et de coïncidences ont été effectuées. Les schémas de niveaux ainsi établis ont permis de mettre en évidence la coexistence de ¹⁸⁵Hg et ¹⁸⁷Hg de deux formes d’équilibre « oblate » et « prolate » toutes deux stabilisées par le nucléon impair dans la couche sphérique νil3/2 ainsi que les b

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