Rozprawy doktorskie na temat „Isotopes of carbon”
Utwórz poprawne odniesienie w stylach APA, MLA, Chicago, Harvard i wielu innych
Sprawdź 50 najlepszych rozpraw doktorskich naukowych na temat „Isotopes of carbon”.
Przycisk „Dodaj do bibliografii” jest dostępny obok każdej pracy w bibliografii. Użyj go – a my automatycznie utworzymy odniesienie bibliograficzne do wybranej pracy w stylu cytowania, którego potrzebujesz: APA, MLA, Harvard, Chicago, Vancouver itp.
Możesz również pobrać pełny tekst publikacji naukowej w formacie „.pdf” i przeczytać adnotację do pracy online, jeśli odpowiednie parametry są dostępne w metadanych.
Przeglądaj rozprawy doktorskie z różnych dziedzin i twórz odpowiednie bibliografie.
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.
Pełny tekst źródłaCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Universidade Estadual Paulista (UNESP)
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 granja comercial. As aves foram divididas em sete grupos distintos distribuídos aleatoriamente em relação às dietas experimentais que continham diferentes percentagens de FVA: 0; 1,5; 3,0; 4,5; 6,0; 7,5 e 15. As dietas foram formuladas de forma a serem isoenergéticas, isoprotéicas e isoaminoacídicas. Quatro aves de cada tratamento foram abatidas aos 42 dias de idade para colheita do músculo peitoral (Pectoralis major), quilha e tíbia para posteriormente serem analisadas. Observou-se enriquecimento isotópico de d13C e d15N nos três tecidos analisados. Em codornas de corte com 42 dias de idade, o nível de inclusão de farinha de vísceras de aves detectado compreende o intervalo de 3,0 a 4,5%.
Detection of animal origin by-products studies in poultry meat are rare and inexistent when related to quail meat. This paper aims the detection of increasing levels of poultry visceral meal (FVA) in quail meat, using carbon (13C/12C) and nitrogen (15N/14N) stable isotopes technique. Sixty four male quails aging one day originally from a commercial producer were divided in seven different groups in a random distribution. Those groups received different experimental diets containing 0; 1,5; 3,0; 4,5; 6,0; 7,5 e 15% of FVA. Those diets were formulated to be isoenergetic, isoproteic and to have the same level of amino-acids. Four individuals per treatment were sacrificed at the 42nd day for breast muscle (Pectoralis major), keel and tibia collection to later analysis. Isotopic enrichment of d13C and d15N were observed in all analyzed tissues. In 42 day old quail were detect a 3,0 and 4,5% poultry visceral meal inclusion in its diet.
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.
Pełny tekst źródłaBanca: Ricardo de Albuquerque
Banca: Carla Cachoni Pizzolante
Banca: Carlos Ducatti
Banca: Ariel Antonio Mendes
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 granja comercial. As aves foram divididas em sete grupos distintos distribuídos aleatoriamente em relação às dietas experimentais que continham diferentes percentagens de FVA: 0; 1,5; 3,0; 4,5; 6,0; 7,5 e 15. As dietas foram formuladas de forma a serem isoenergéticas, isoprotéicas e isoaminoacídicas. Quatro aves de cada tratamento foram abatidas aos 42 dias de idade para colheita do músculo peitoral (Pectoralis major), quilha e tíbia para posteriormente serem analisadas. Observou-se enriquecimento isotópico de d13C e d15N nos três tecidos analisados. Em codornas de corte com 42 dias de idade, o nível de inclusão de farinha de vísceras de aves detectado compreende o intervalo de 3,0 a 4,5%.
Abstract: Detection of animal origin by-products studies in poultry meat are rare and inexistent when related to quail meat. This paper aims the detection of increasing levels of poultry visceral meal (FVA) in quail meat, using carbon (13C/12C) and nitrogen (15N/14N) stable isotopes technique. Sixty four male quails aging one day originally from a commercial producer were divided in seven different groups in a random distribution. Those groups received different experimental diets containing 0; 1,5; 3,0; 4,5; 6,0; 7,5 e 15% of FVA. Those diets were formulated to be isoenergetic, isoproteic and to have the same level of amino-acids. Four individuals per treatment were sacrificed at the 42nd day for breast muscle (Pectoralis major), keel and tibia collection to later analysis. Isotopic enrichment of d13C and d15N were observed in all analyzed tissues. In 42 day old quail were detect a 3,0 and 4,5% poultry visceral meal inclusion in its diet.
Doutor
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.
Pełny tekst źródłaCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Universidade Estadual Paulista (UNESP)
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 segundo tanque eram alimentados com uma mistura de baixa proteína (MBP; δ13C = 10 -14,34‰) e os animais dos outros tanques tinham acesso livre a ambas, quatro vezes ao 11 dia. Foram realizadas coletas de músculo, fígado e sangue a cada cinco dias por 86 dias, 12 exceto para o grupo alimentado com MBP (alimentado por 120 dias). As amostras 13 foram analisadas em espectrômetro de massa e as proporções consumidas das misturas 14 foram estimadas a partir do enriquecimento isotópico do carbono (δ13C). O 15 balanceamento realizado indicou redução no consumo relativo de proteína. Contudo, 16 esta relação não apresentou padrão definido em relação ao peso dos indivíduos, ou seja: 17 o balanceamento de proteína e energia para tilápia do Nilo está relacionado 18 principalmente à idade dos animais e não é claro se este processo está relacionado 19 também ao seu peso. As estimativas de consumo de um grupo animais desta espécie por 20 meio dos isótopos estáveis de carbono são semelhantes aos obtidos por outras técnicas, 21 portanto este método permite observação da diversidade deste comportamento no 22 autobalanceamento entre os indivíduos que compõe tal grupo.
This study aimed to assess the Nile tilapia ability to balance its own diet, 6 when two ingredient mixes were offered, using carbon stable isotopes. In order to 7 accomplish that, 225 Nile tilapia juveniles (average initial weight 5.0g ± 0.5g) were 8 distributed in five tanks, each containing a group of 45 fish. One group of fish were fed 9 exclusively a high protein mix (HPM; δ13C = -22.62‰), a second one fed only a low 10 protein mix (LPM; δ13C = -14.34‰). The other groups had free access to both mixes 11 (free choice system). The fish from all tanks were fed four times a day. Muscle, liver 12 and blood samples were collected at each five days (from 2 fish/tank/collection) for 86 13 days, except for the fish fed with MBP (fed for a 120 days period). The samples were 14 analyzed in a mass spectrometer and proportions of the mixes consumed were estimated 15 through its carbon isotope enrichment (δ13C). The fish diminished their protein intake 16 along the time. However, consumption did not present a clear pattern in relation to the 17 individual weight, i.e.: protein consumption patterns are mainly related to the age of the 18 individuals and it is not clear if it is also correlated to their weight. The consumption 19 estimative through stable isotopes of carbon did not conflict other studies reported in the 20 literature. Additionally this technique allowed observation of consumption among the 21 individuals from an experimental group 22.
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.
Pełny tekst źródłaBanca: Wilson Massamitu Furuya
Banca: José Fernando Machado Menten
Banca: Carlos Ducatti
Banca: José Roberto Sartori
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 segundo tanque eram alimentados com uma mistura de baixa proteína (MBP; δ13C = 10 -14,34‰) e os animais dos outros tanques tinham acesso livre a ambas, quatro vezes ao 11 dia. Foram realizadas coletas de músculo, fígado e sangue a cada cinco dias por 86 dias, 12 exceto para o grupo alimentado com MBP (alimentado por 120 dias). As amostras 13 foram analisadas em espectrômetro de massa e as proporções consumidas das misturas 14 foram estimadas a partir do enriquecimento isotópico do carbono (δ13C). O 15 balanceamento realizado indicou redução no consumo relativo de proteína. Contudo, 16 esta relação não apresentou padrão definido em relação ao peso dos indivíduos, ou seja: 17 o balanceamento de proteína e energia para tilápia do Nilo está relacionado 18 principalmente à idade dos animais e não é claro se este processo está relacionado 19 também ao seu peso. As estimativas de consumo de um grupo animais desta espécie por 20 meio dos isótopos estáveis de carbono são semelhantes aos obtidos por outras técnicas, 21 portanto este método permite observação da diversidade deste comportamento no 22 autobalanceamento entre os indivíduos que compõe tal grupo.
Abstract: This study aimed to assess the Nile tilapia ability to balance its own diet, 6 when two ingredient mixes were offered, using carbon stable isotopes. In order to 7 accomplish that, 225 Nile tilapia juveniles (average initial weight 5.0g ± 0.5g) were 8 distributed in five tanks, each containing a group of 45 fish. One group of fish were fed 9 exclusively a high protein mix (HPM; δ13C = -22.62‰), a second one fed only a low 10 protein mix (LPM; δ13C = -14.34‰). The other groups had free access to both mixes 11 (free choice system). The fish from all tanks were fed four times a day. Muscle, liver 12 and blood samples were collected at each five days (from 2 fish/tank/collection) for 86 13 days, except for the fish fed with MBP (fed for a 120 days period). The samples were 14 analyzed in a mass spectrometer and proportions of the mixes consumed were estimated 15 through its carbon isotope enrichment (δ13C). The fish diminished their protein intake 16 along the time. However, consumption did not present a clear pattern in relation to the 17 individual weight, i.e.: protein consumption patterns are mainly related to the age of the 18 individuals and it is not clear if it is also correlated to their weight. The consumption 19 estimative through stable isotopes of carbon did not conflict other studies reported in the 20 literature. Additionally this technique allowed observation of consumption among the 21 individuals from an experimental group 22.
Doutor
Linebaugh, Donald W. "Carbon cycling in the York River Estuary: an isotopic and mass balance approach using natural Carbon-14 and Carbon-18 isotopes". W&M ScholarWorks, 1999. https://scholarworks.wm.edu/etd/1539791832.
Pełny tekst źródłaÖsterlin, Carl. "STABLE CARBON ISOTOPES IN SPELEOTHEMS FROM TEMPERATE AREAS". Thesis, Stockholms universitet, Institutionen för naturgeografi och kvartärgeologi (INK), 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-55353.
Pełny tekst źródłaCurtis-Summers, Shirley. "Stable Isotopes of Carbon and Nitrogen and Diet". Society of Antiquaries of Scotland, 2016. http://hdl.handle.net/10454/17856.
Pełny tekst źródłaSadurski, Stephen Edward. "The Biogeochemistry of Carbon Isotopes in Local Lakes". Wright State University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=wright1357745315.
Pełny tekst źródłaSchlanser, Kristen M. "Advancing Leaf Carbon Isotopes as a Paleo Proxy". University of Cincinnati / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ucin159584747503534.
Pełny tekst źródłaMcNichol, Ann P. "A study of remineralization of organic carbon in nearshore sediments using carbon isotopes /". Woods Hole, Mass. : Woods Hole Oceanographic Institution, 1986. http://hdl.handle.net/1912/3228.
Pełny tekst źródłaLo, Tierzo Vivian [UNESP]. "Turnover do carbono nos tecidos de suínos em diferentes fases de crescimento". Universidade Estadual Paulista (UNESP), 2007. http://hdl.handle.net/11449/104053.
Pełny tekst źródłaCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Universidade Estadual Paulista (UNESP)
Este trabalho objetivou determinar o turnover do carbono no sangue, pâncreas e tíbia de suínos em diferentes períodos de crescimento, utilizando a técnica de isótopos estáveis. Foram utilizados 132 machos castrados e fêmeos, distribuídos ao acaso em quatros tratamentos que consistiam da substituição da dieta a base de milho (planta de ciclo fotossintético C4) por dieta a base de arroz (plantas do ciclo fotossintético C3) em dias distintos: 21; 42; 63; 110 dias de idade, respectivamente para os tratamentos 1, 2, 3 e 4. Para mensurar o turnover do carbono (diluição isotópica) nos tecidos em determinado intervalo de tempo, foram utilizados o modelo de equações de função exponencial do tempo ou modelo sigmoidal de regressão de Boltzmann. Os valores de meias-vidas foram: 15,9; 19,0 e 16,8 dias para o sangue; 14,1; 9,68 e 10,4 dias para o pâncreas; 14,3; 8,0 e 15,1 dias para tíbia com medula nos tratamentos com substituição aos 21, 42 e 63 de idade respectivamente. O pâncreas de acordo com valores de meia vida apresentou um rápido turnover, o sangue e a tíbia com medula apresentaram maiores valores de meia vida
This study aimed to determine the turnover of carbon in the blood, tibia and pancreas of pigs at different growth periods, using the technique of stable isotopes. We used 132 barrows and females were randomly assigned into four groups consisting of replacing the corn-based diet (plant C4 photosynthetic cycle) by diet of rice (C3 photosynthetic cycle plants) on different days: 21; 42, 63; 110 days of age, respectively for treatments 1, 2, 3 and 4. To measure the turnover of carbon (isotope dilution) in tissues given time interval, we used the model equations exponential function of time or template Boltzmann sigmoidal regression. Values of half-lives were 15.9, 19.0 and 16.8 days for the blood; 14.1, 9.68 and 10.4 days for the pancreas, 14.3, 8.0 and 15, one day to the tibia with bone replacement treatments at 21, 42 and 63 of age respectively. The pancreas according to half-life values showed a rapid turnover, blood and tibia with bone showed higher half-life
Archbold, M. E. "Carbon isotopes of volatile organic compounds for environmental tracing". Thesis, Queen's University Belfast, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.419452.
Pełny tekst źródłaCrichton, Katherine. "The role of permafrost soils in the global carbon-cycle on the timescales of centuries to multi-millennia : a modelling study". Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENU049/document.
Pełny tekst źródłaThis study aimed to develop a permafrost-carbon dynamic model to incorporate into the CLIMBER-2 Earth system model and to carry out simulations with a view to contributing to the knowledge of the carbon cycle. The work would, for the first time, allow a fully coupled modelling study with an earth system model which included dynamic atmosphere, ocean, vegetation and cryosphere components including frozen land to study paleoclimates. The availability of recent ice core data for CO2 and δ13C of atmospheric CO2 was to provide a means of validating model findings to identify whether a permafrost-carbon dynamic could have played a significant role in past changing climates.The deep Southern Ocean is an area of particular interest for glacial-interglacial CO2 variability, and current modelling efforts aim to recreate the observed CO2 changes using ocean mechanisms. These are often related to deep southern ocean carbon storage and release. So far the terrestrial biosphere has not been well-considered in transient simulations of the carbon cycle in Earth system models.A simplified permafrost-carbon mechanism was developed and validated and tuned using data from termination 1. It was found that in order to reproduce atmospheric CO2 and δ13C data (for atmosphere and ocean) during the termination, a combination of glacial ocean mechanisms and the permafrost-carbon mechanism was required. Following this finding, several glacial cycles were modelled to study the sensitivity of the permafrost-carbon mechanisms to CO2, ice sheets and insolation. Ice sheet extent was found to be particularly important in controlling the land area available for permafrost and therefore the carbon dynamics of permafrost-carbon. The permafrost-carbon mechanism, via carbon release from thawing soils responding to increasing summer insolation in higher northern latitudes, was found to very likely be the source of initial rises in CO2 on glacial terminations.Termination 1 CO2 data could be well reproduced, including the B-A/YD CO2 plateau, when fresh water forcing was applied to the north Atlantic. Fresh water forcing experiments pointed to the importance of the permafrost-carbon mechanism in fast changing climates. Very fast increases in atmospheric CO2 levels may be explained by fast soil-carbon release responding to increased heat transport to the northern hemisphere on AMOC resumption following an AMOC switch-off/reduction event, such as D/O events seen in the Greenland δ18O record. Future climate change projections represent fast warming events. Driving the model by emissions projections (RCP database) predicted increased peak CO2 and much longer term elevated CO2 levels relative to model outputs which did not include the permafrost carbon feedback.Analysis of ocean δ13C must take into account the dynamics of permafrost and land carbon in general and its effect on atmospheric δ13C levels. If this is not taken into account then ocean circulation may be over-invoked in attempting to explain changes in ocean δ13C and atmospheric CO2. The Earth system is not simply atmosphere and ocean. The findings in this work highlight that it is essential to consider land carbon dynamics when interpreting paleo-indicators for the carbon cycle.The permafrost-carbon mechanism reacts to temperature changes and amplifies the carbon cycle's response. It is stongly dependent not only on energy input (that determines soil temperature and permafrost location), but also on the area of land available globally on which it can exist. In order to properly model and understand the Earth system response to forcing in both future and past climates, the permafrost-carbon feedback mechanism is an important system component. This work has been a first step to address the role that the land cryosphere plays in the carbon cycle and climate system on long timescales, and further studies are essential
McNichol, Ann P. 1956. "A study of the remineralization of organic carbon in nearshore sediments using carbon isotopes". Thesis, Massachusetts Institute of Technology, 1986. http://hdl.handle.net/1721.1/58489.
Pełny tekst źródłaVita.
Includes bibliographical references (leaves 208-215).
A study of the remineralization of organic carbon was conducted in the organic-rich sediments of Buzzards Bay, MA. Major processes affecting the carbon chemistry in sediments are reflected by changes in the stable carbon isotope ratios of dissolved inorganic carbon (XCO2) in sediment pore water. Six cores were collected seasonally over a period of two years. The following species were measured in the pore waters: JC02, &'3 C-2CO2, P04, JH 2S, Alk, DOC, and Ca. Measurements of pore water collected seasonally show large gradients with depth, which are larger in summer than in winter. The 613C (PDB) of IC02 varies from 1.3 o/oo in the bottom water to approximately -10 o/oo at 30 cm. During all seasons, there was a trend towards more negative values with depth in the upper 8 cm due to the remineralization of organic matter. There was a trend toward more positive values below 8 cm, most likely due to biological irrigation of sediments with bottom water. Below 16-20 cm, a negative gradient was re-established which indicates a return to remineralization as the main process affecting pore water chemistry. Using the XC02 depth profile, it was estimated that 67-85 gC/m 2 are oxidized annually and 5 gC/m 2-yr are buried. The amount of carbon oxidized represented remineralization occurring within the sediments. This estimate indicated that approximately 20% of the annual primary productivity reached the sediments. The calculated remineralization rates varied seasonally with the high of 7.5 x 10-' mol/L-sec observed in August 84 and the low (0.6 x 10-) in December 83. The calculated remineralization rates were dependent on the amount of irrigation in the sediments; if the irrigation parameter is known to ±20%, then the remineralization rates are known to this certainty also. The amount of irrigation in the sediments was estimated using the results of a seasonal study of 2 2 2Rn/ 22 'Ra disequilibria at the same study site (Martin, 1985). Estimates of the annual remineralization in the sediments using solid-phase data indicated that the solid-phase profiles were not at steady-state concentrations. The isotopic signature of 2C02 was used as an indicator of the processes affecting IC02 in pore water. During every month, the oxidation of organic carbon to C02 provided over half of the carbon added to the IC02 pool. However, in every month, the 6'"C of XCO2 added to the pore water in the surface sediments was greater than -15 o/oo, significantly greater than the 613C of solid-phase organic carbon in the sediments (-20.6 o/oo). The 613C of IC02 added to the pore water in the sediments deeper than 7 cm was between -20 and -21 o/oo, similar to the organic carbon in the sediments. Possible explanations of the 1 3C-enrichment observed in the surface sediments were: a) significant dissolution of CaC0 3 (613C = +1.7 o/oo) b) the addition of significant amounts of carbonate ion from bottom water to pore water c) an isotopic difference between the carbon oxidized in the sediments and that remaining in the sediments. The effect of CaC0 3 dissolution was quantified using measured dissolved Ca profiles and was not large enough to explain the observed isotopic enrichment. An additional source of 13C-enriched carbon was bottom water carbonate ion. In every month studied, there was a net flux of 2C0 2 from pore water to bottom water. The flux of pore water 2C02 to bottom water ranged from a minimum of 10 x 10-12 mol/cm 2 -sec in December 83 to a maximum of 50 x 10-12 mol/cm2-sec in August 84. However, because the pH of bottom water was about 8 while that of the pore water was less than or equal to 7, the relative proportion of the different species of inorganic carbon (H2CO, HCO-, C0~) was very different in bottom water and pore water. Thus, while there was a net flux of IC0 2 from pore water to bottom water, there was a flux of carbonate ion from bottom water to pore water. Because bottom water JC02 was more 13C-enriched than pore water JC0 2, the transfer of bottom water carbonate ion to pore water was a source of 13C-enriched carbon to the pore water. If the &'3C of CO2 added to the pore water from the oxidation of organic carbon was -20.6 o/oo, then the flux of C3% from bottom water to pore water must have been 10-30% of the total flux of 2C02 from pore water to bottom water. This is consistent with the amount calculated from the observed gradient in carbonate ion. Laboratory experiments were conducted to determine whether the 613C of C02 produced from the oxidation of organic carbon (613C-OCOX) was different from the 613C of organic carbon in the sediments (613C-SOC). In the laboratory experiments, mud from the sampling site was incubated at a constant temperature. Three depths were studied (0-3, 10-15, and 20-25 cm). For the first study (IEl), sediment was stirred to homogenize it before packing into centrifuge tubes for incubation. For the second study (IE2), sediment was introduced directly into glass incubation tubes by subcoring. The second procedure greatly reduced disturbance to the sediment. Rates of C02 production were calculated from the concentrations of 2C02 measured over up to 46 days. In both studies, the values of Re in the deeper intervals were about 10% of the surface values. This was consistent with the field results, although the rates decreased more rapidly in the field. In all cases, the remineralization rates during the beginning of IEl were much greater than those at the beginning of IE2. The sediment for IEl was collected in February 84. The measured value of Rc in the surface sediment of the laboratory experiment (24 x 10- mol/L-sec) was much greater than the value of Rc observed in the field in another winter month, December 83 (.62 x 10~9). The sediment for IE2 was collected in August 85. The measured values of Re in the surface sediment (6.6-12 x 10~9 mol/L-sec) were consistent with the field values from August 84 (7.5 x 10-9). The XC02 results indicated that IE2 reproduced field conditions more accurately than IEl did. The isotopic results from the experiments strongly suggested that 613C-OCOX in the surface sediments (-17.8 o/oo ± 1.9 o/oo) was greater than 6'3C-SOC (-20.6 ± 0.2 o/oo). The magnitude of the observed fractionation was small enough that the observed values of 613C-C02 in the pore waters could be explained by fractionated oxidation coupled with the diffusion of carbonate ion from bottom water to pore water. The observed fractionation was most likely due to the multiple sources of organic carbon to coastal sediments. A study of the natural levels of radiocarbon in these sediments indicated that the carbon preserved in the sediments is approximately 30% terrestrial while the rest is from phytoplankton.
by Ann P. McNichol.
Ph.D.
Gardner, Adele F. "An organic geochemical study of the Cretaceous/Tertiary boundary". Thesis, Open University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321559.
Pełny tekst źródłaEek, Magnus. "Environmental control of stable carbon isotope systematics in Emiliania huxleyi". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0017/NQ52759.pdf.
Pełny tekst źródłaGilmour, Iain. "The distribution of carbon stable isotopes within sedimentary organic matter". Thesis, University of Cambridge, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.373660.
Pełny tekst źródłaDixon, Luke Ian. "Introduction of carbon isotopes into organic frameworks using alkynyiodonium salts". Thesis, University of Newcastle Upon Tyne, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.578554.
Pełny tekst źródłaSweeting, Christopher J. "Carbon and nitrogen stable isotopes as descriptors of fish trophodynamics". Thesis, University of Newcastle Upon Tyne, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.405361.
Pełny tekst źródłaVainonen-Ahlgren, Elizaveta. "Release of hydrogen isotopes from carbon based fusion reactor materials". Helsinki : University of Helsinki, 2000. http://ethesis.helsinki.fi/julkaisut/mat/fysii/vk/vainonen-ahlgren/.
Pełny tekst źródłaVaiglova, 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.
Pełny tekst źródłaCoularis, Cindy. "Dynamique et transfert du carbone dans le bassin versant de la Loire : Traçage par les isotopes du carbone". Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS132.
Pełny tekst źródłaThis thesis focuses on carbon cycle in the Loire River and its major tributaries. It aims to (1) use isotopic composition (14C and 13C) to describe the sources, the nature and the age of the Dissolved Inorganic and Organic Carbon (DIC, DOC) and of the Particular Organic Carbon (POC) sampled during four campaigns in 2013 and 2014; and (2) to use anthropogenic 14C found in the liquid releases of the 5 Nuclear Power Plants (NPP) operating in the basin as a tool to track carbon transfer between the different phases.Archaeologists demonstrated that 14C ages of samples coming from bones or non-human material (potteries, ceramics, sediments,…) are not in balanced with the atmosphere of the time they were created and thus need to be corrected. This bias stems from the age of water (as beverage or raw material), and more precisely the DIC age, also known as reservoir age. In the Loire River and its tributaries, DIC mainly comes from erosion and dissolution of the geological substratum. DIC concentrations are higher in the carbonated areas located in the middle Loire. As the reservoir ages are directly related to the DIC content, their values present a wide spatial variability (from 135 to 2251 yr 14C BP) because the Loire River and its tributaries cross areas with variable content of carbonates among their geological formations.Also, DIC is mainly absorbed during photosynthetic processes that produce algal POC. Algal POC and detrital POC form the particulate organic matter (OM). POC concentrations follow a temporal cycle with higher values during Spring time. Algal carbon marking depends on the DIC isotopic signature used by the chlorophyll synthesis. Reservoir ages calculated from POC values range from 306 to 1597 14C years, with the same spatial and temporal variation as the DIC. Algal carbon ratio, ranging from 2 to 100%, depends on the river, and climatic and hydrologic conditions. However, no systematic pattern can be found. The detrital fraction of POC has an activity close to the activity of POC and algal POC involving that the component is not of geological origin and thus, it is not refractory.The decomposition of this particular OM, the metabolic activity of organisms (lysis and exudation) and the input of old OM from the river, the soil or the groundwater are all sources for DOC production. Thus, DOC concentrations follow the same seasonal pattern as the POC. However, DOC contents are higher than the POC ones, and increase a bit from upstream to downstream (±1mg/L). It can be aged if POC and/or exported OM are old. Thus reservoir ages in the DOC range from 101 to 2494 14C years in April 2013, with older ages in agricultural areas.Not only did the use of anthropogenic 14C made it possible to visualize transfers between different phases, but also it confirmed the emission of enriched 14CDIC and unconfirmed the emission of 14CPOC and 14CDOC by the NPP. However, the 14CDIC activity does not represent the complete activity of the release because of water-atmosphere exchange involving 14C outflow. The marked POC records the initial NPP liquid release activity using the DIC from the NPP. The POC being isolated from the atmosphere, the POC measured activity is close to the originate activity in the release.All these data combined to the understanding of the transfers processes between DIC, POC and DOC will make it possible to improve the existing prediction model and, eventually, to anticipate the behavior of this radionuclide in the river from its emission to its arrival in the estuary and then in the Atlantic Ocean
Hall, Nicola. "Stable isotopes, molecular markers and water use in Brassicas". Thesis, University of Newcastle Upon Tyne, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.324874.
Pełny tekst źródłaBarral, Cuesta Abel. "The carbon isotope composition of the fossil conifer Frenelopsis as a proxy for reconstructing Cretaceous atmospheric CO2". Thesis, Lyon, 2016. http://www.theses.fr/2016LYSE1148.
Pełny tekst źródłaThe Cretaceous was a period characterized by strongly marked climate change and major carbon cycle instability. Atmospheric CO2 has repeatedly been pointed out as a major agent involved in these changing conditions during the period. However, long-term trends in CO2 described for the Cretaceous are not consistent with those of temperature and the large disturbance events of the carbon cycle described for the period. This raises a double question of whether descriptions of the long-term evolution of atmospheric CO2 made so far are accurate or, if so, atmospheric CO2 was actually a major driver of carbon cycle and climate dynamics as usually stated. In this thesis the close relationship between the carbon isotope composition of plants and atmospheric CO2 is used to address this question. Based on its ecological significance, distribution, morphological features and its excellent preservation, the fossil conifer genus Frenelopsis is proposed as a new plant proxy for climate reconstructions during the Cretaceous. The capacity of carbon isotope compositions of Frenelopsis leaves (d13Cleaf) to reconstruct past atmospheric CO2, with regards to both carbon isotope composition (d13CCO2) and concentration (pCO2), is tested based on materials coming from twelve Cretaceous episodes. To provide a framework to test the capacity of d13Cleaf to reconstruct d13CCO2 and allowing for climate estimates from carbon isotope discrimination by plants (?13Cleaf), a new d13CCO2 curve for the Cretaceous based on carbon isotope compositions of marine carbonates has been constructed. Comparison with d13Cleaf-based d13CCO2 estimates reveals that although d13CCO2 and d13Cleaf values follow consistent trends, models developed so far to estimate d13CCO2 from d13Cleaf tend to exaggerate d13CCO2 trends because of assuming a linear relationship between both values. However, given the hyperbolic relationship between ?13Cleaf and pCO2, by considering an independently-estimated correction factor for pCO2 for a given episode, d13Cleaf values may be a valuable proxy for d13CCO2 reconstructions. ?13Cleaf estimates obtained from d13CCO2 and d13Cleaf values were used to reconstruct the long-term evolution of pCO2. The magnitude of estimated pCO2 values is in accordance with that of the most recent and relevant model- and proxy-based pCO2 reconstructions. However, these new results evidence long-term drawdowns of pCO2 for Cretaceous time intervals in which temperature maxima have been described
Sernagiotto, Erica Regina [UNESP]. "Rastreabilidade da farinha de vísceras de aves em codornas submetidas a longo período de criação utilizando a técnica dos isótopos estáveis 'delta' 'intpot. 13 c' e 'delta' 'intpot. 15 N'". Universidade Estadual Paulista (UNESP), 2009. http://hdl.handle.net/11449/95279.
Pełny tekst źródłaCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Universidade Estadual Paulista (UNESP)
O presente trabalho teve por objetivo avaliar a capacidade da técnica dos isótopos estáveis em rastrear a farinha de vísceras de aves (FVA), na alimentação de codornas de corte criadas por longo período, após a substituição da dieta com 8% de FVA por dieta vegetal. Foram utilizadas 320 codornas, distribuídas aleatoriamente em oito tratamentos: dieta vegetal (T1) e sete tratamentos com inclusão de 8% de FVA na dieta, um mantendo a dieta até o final do período experimental (T2), e nos demais a dieta foi substituída aos 42; 56; 70; 84; 98; 112 dias; respectivamente, por dieta vegetal. Para coleta das amostras de músculo peitoral foram sacrificadas ao acaso, quatro aves (n = 4) por tratamento, a cada 14 dias, sendo que no T1 e T2 tiveram início aos 42 dias e nos demais a partir da troca das dietas. Os resultados isotópicos obtidos foram submetidos à análise multivariada de variância (MANOVA) com auxílio do procedimento GLM do programa estatístico SAS. Os tratamentos diferiram do vegetal quando as aves foram sacrificadas duas semanas após a troca da dieta; após esse período os tratamentos experimentais tiveram comportamento semelhante ao vegetal, exceto o T3, que se mostrou semelhante ao T1 no abate 14 dias após a troca da dieta; e do T2 que em todos os períodos de comparação diferiu do T1. Conclui-se que a aplicação da técnica dos isótopos estáveis de carbono e nitrogênio na rastreabilidade da FVA, na alimentação de codornas de corte criadas por longo período é possível nas aves abatidas 14 dias após a troca de dieta, com exceção das aves sacrificadas aos 56 dias de idade.
The present work aimed to evaluate the capability of the stable isotope technique to trace poultry visceral meal (PVM) in the diet of meat quails raised for a long period after substitution of an 8% PVM diet for a vegetable diet. Three hundred and twenty poultries (320) were randomly distributed into eight treatments: vegetable diet (T1) and seven treatments containing 8% PVM in the diet: in one treatment, the same diet was kept until the end of the experimental period (T2), and in the remaining treatments, the diet was substituted at 42, 56, 70, 84, 98, and 112 days, respectively, for a vegetable diet. To collect chest muscle samples, four poultries (n = 4) per treatment were randomly sacrificed at every 14 days, starting at 42 days in T1 and T2 and from diet substitution in the remaining treatments. The obtained isotopic results were subjected to multivariate analysis of variance (MANOVA) using the GLM procedure of SAS statistical software. Treatments differed from the vegetable diet when poultries were sacrificed at two weeks following the diet substitution; after such period, the behavior of experimental treatments was similar to that of the vegetable diet, except for T3, which was similar to T1 at slaughtering at 14 days after the diet substitution, and T2 which, in all comparison periods, differed from T1. In conclusion, the technique of stable isotopes of carbon and nitrogen can be used to trace PVM in the diet of meat quails slaughtered at 14 days after diet substitution, except for poultries sacrificed at 56 days.
Lo, Tierzo Vivian 1982. "Turnover do carbono nos tecidos de suínos em diferentes fases de crescimento /". Botucatu : [s.n.], 2012. http://hdl.handle.net/11449/104053.
Pełny tekst źródłaBanca: Fabiana Ribeiro Caldara
Banca: Dirlei Antonio Berto
Banca: Juliana Célia Denadai
Banca: Léa Silvia Sant'Ana
Banca: José Albertino Bendassolli
Resumo: Este trabalho objetivou determinar o turnover do carbono no sangue, pâncreas e tíbia de suínos em diferentes períodos de crescimento, utilizando a técnica de isótopos estáveis. Foram utilizados 132 machos castrados e fêmeos, distribuídos ao acaso em quatros tratamentos que consistiam da substituição da dieta a base de milho (planta de ciclo fotossintético C4) por dieta a base de arroz (plantas do ciclo fotossintético C3) em dias distintos: 21; 42; 63; 110 dias de idade, respectivamente para os tratamentos 1, 2, 3 e 4. Para mensurar o turnover do carbono (diluição isotópica) nos tecidos em determinado intervalo de tempo, foram utilizados o modelo de equações de função exponencial do tempo ou modelo sigmoidal de regressão de Boltzmann. Os valores de meias-vidas foram: 15,9; 19,0 e 16,8 dias para o sangue; 14,1; 9,68 e 10,4 dias para o pâncreas; 14,3; 8,0 e 15,1 dias para tíbia com medula nos tratamentos com substituição aos 21, 42 e 63 de idade respectivamente. O pâncreas de acordo com valores de meia vida apresentou um rápido turnover, o sangue e a tíbia com medula apresentaram maiores valores de meia vida
Abstract: This study aimed to determine the turnover of carbon in the blood, tibia and pancreas of pigs at different growth periods, using the technique of stable isotopes. We used 132 barrows and females were randomly assigned into four groups consisting of replacing the corn-based diet (plant C4 photosynthetic cycle) by diet of rice (C3 photosynthetic cycle plants) on different days: 21; 42, 63; 110 days of age, respectively for treatments 1, 2, 3 and 4. To measure the turnover of carbon (isotope dilution) in tissues given time interval, we used the model equations exponential function of time or template Boltzmann sigmoidal regression. Values of half-lives were 15.9, 19.0 and 16.8 days for the blood; 14.1, 9.68 and 10.4 days for the pancreas, 14.3, 8.0 and 15, one day to the tibia with bone replacement treatments at 21, 42 and 63 of age respectively. The pancreas according to half-life values showed a rapid turnover, blood and tibia with bone showed higher half-life
Doutor
Leask, Peter John. "Probing nuclear molecular analogue states in carbon, boron and beryllium isotopes". Thesis, University of Birmingham, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.369340.
Pełny tekst źródłaBradbury, Harold John. "Calcium isotope insight into the global carbon cycle". Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/273425.
Pełny tekst źródłaLee, Kern Y. "Carbon Cycling in Tropical Rivers: A Carbon Isotope Reconnaissance Study of the Langat and Kelantan Basins". Thèse, Université d'Ottawa / University of Ottawa, 2014. http://hdl.handle.net/10393/30429.
Pełny tekst źródłaHarrison, Roman Gastrell. "Paleodiet studies using stable carbon isotopes from bone apatite and collagen". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0021/NQ54785.pdf.
Pełny tekst źródłaWellman, Toby. "Carbon and oxygen stable isotopes from recent and fossil Australian crustaceans /". Title page, contents and abstract only, 2001. http://web4.library.adelaide.edu.au/theses/09SB/09sbw4528.pdf.
Pełny tekst źródłaWebb, Sarah Christine. "Stable carbon and nitrogen isotopes in insects : the influence of diet". Thesis, University of Oxford, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.389063.
Pełny tekst źródłaAsher, Cameron Michael. "Carbon and nitrogen isotopes in lichen as a geothermal exploration tool". Thesis, University of Canterbury. Geological Sciences, 2014. http://hdl.handle.net/10092/9651.
Pełny tekst źródłaBoyd, Stuart Richard. "A study of carbon and nitrogen isotopes from the Earth's mantle". Thesis, Open University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.252682.
Pełny tekst źródłaSimpson, Nicola Jane. "Carbon isotopes and the plant fossil record : taphonomic and diagenetic controls". Thesis, Open University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.301876.
Pełny tekst źródłaTrandel, Marlee Anne. "Nitrogen and Carbon Stable Isotopes in Organically and Conventionally Grown Tomatoes". OpenSIUC, 2016. https://opensiuc.lib.siu.edu/theses/2013.
Pełny tekst źródłaJohnson, Brian James. "The carbon-13 content of atmospheric formaldehyde". Diss., The University of Arizona, 1988. http://hdl.handle.net/10150/184320.
Pełny tekst źródłaAssis, Cecília Kruszynski de. "Diet and ecosystem services of insectivorous bats assessed with stable isotopes". Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/64/64135/tde-07032019-103440/.
Pełny tekst źródłaServiços ecossistêmicos são funções dos ambientes naturais e dos processos ecológicos dos quais humanos se beneficiam. Esses benefícios podem ser acessados por uma perspectiva econômica e ecológica. No presente estudo, nós destacamos um dos serviços ambientais fornecidos por morcegos: controle de pragas agrícolas. No Brasil, os estudos com morcegos insetívoros como potenciais supressores de pragas ainda são escassos, apesar de o país ser um dos maiores produtores agrícolas do mundo e abrigar uma alta diversidade desses animais. O uso de paisagens heterogêneas, formadas por vegetação nativa e lavouras agrícolas, otimiza o investimento aplicado nessa busca. Para tanto, descrevemos, pela primeira vez, a assembleia de morcegos em um ambiente heterogêneo de Piracicaba, o campus \"Luiz de Queiroz\", que possui desde áreas urbanizadas a agrícolas, disponibilizando diversos recursos alimentares para os morcegos. Ademais, testamos se há diferenças nos valores isotópicos (?13C e ?15N) entre as espécies de morcegos em relação à dieta, comportamento espacial de forrageamento, sexo ou classificação taxonômica para identificar quais grupos são os melhores supressores de pragas agrícolas. Utilizamos redes de neblina para a captura dos morcegos e análises de isótopos estáveis de carbono e nitrogênio (?13C e ?15N, respectivamente) para acessar sua fonte de dieta. Por meio das análises, determinamos a proporção de plantas com ciclos fotossintéticos do tipo C3 e C4 na dieta dos morcegos, bem como seu nível trófico. Capturamos 90 morcegos de 11 espécies, três famílias e quatro classes de dieta, correspondendo a 66% da riqueza estimada para o local. Destas, cinco são espécies classificadas insetívoras. Molossus molossus foi a espécie mais abundante, seguida por Artibeus lituratus e Glossophaga soricina. Valores de ?13C mostraram que insetívoros, frugívoros e nectarívoros consomem insetos, inclusive pragas, em diferentes proporções por espécie e grupo de dieta. O grupo mais efetivo no controle de pragas agrícolas foi M. molossus, seguido por A. planirostris. Os valores de ?15N mostraram que o nível trófico dos diferentes grupos alimentares de morcegos foi similar, de modo que eles são mais generalistas que previsto na literatura. Nosso estudo aponta a necessidade de quantificação desse importante serviço ecossistêmico promovido por morcegos, que podem reduzir doenças e prejuízos nas lavouras, além de combater vetores de doenças
Shelkov, Denis Alexander. "N and C isotropic composition of different varieties of terrestrial diamonds and carbonado". Thesis, Open University, 1997. http://oro.open.ac.uk/54608/.
Pełny tekst źródłaStrange, Malinda Range. "The effect of pathology on the stable isotopes of carbon & nitrogen". Diss., Online access via UMI:, 2006.
Znajdź pełny tekst źródłaWarrington, Anita Glasgow. "Stable isotopes of carbon and oxygen in the shells of terrestrial molluscs". Thesis, University of Liverpool, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.316976.
Pełny tekst źródłaHarwood, Kirsty. "Variation in the stable isotopes of oxygen and carbon within forest canopies". Thesis, University of Newcastle Upon Tyne, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.360330.
Pełny tekst źródłaCutajar, Josephine-Anne. "Characterisation of aerosols using carbon and lead stable isotopes and trace elements". Thesis, Open University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.339859.
Pełny tekst źródłaCassar, Nicolas. "Carbon-concentrating mechanisms and [beta]-carboxylation their potential contribution to marine photosynthetic carbon isotope fractionation /". Thesis, University of Hawaii at Manoa, 2003. http://proquest.umi.com/pqdweb?index=0&did=765084611&SrchMode=2&sid=6&Fmt=2&VInst=PROD&VType=PQD&RQT=309&VName=PQD&TS=1233178277&clientId=23440.
Pełny tekst źródłaGentry, David Keith. "Seasonal isotope and trace-metal profiles of serially-sampled Conus gastropods: proxies for paleoenvironmental change". Thesis, Texas A&M University, 2003. http://hdl.handle.net/1969.1/3871.
Pełny tekst źródłaOgle, Neil. "The measurement and modelling of #delta#'1'3C in Irish oaks". Thesis, Queen's University Belfast, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.295402.
Pełny tekst źródłaAhad, Jason Michael Elias. "Monitoring stable carbon isotopes during biodegradation of toluene, implications for contaminated site assessment". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0023/MQ50399.pdf.
Pełny tekst źródłaHemming, D. L. "Stable isotopes in tree rings : biosensors of climate and atmospheric carbon-dioxide variations". Thesis, University of Cambridge, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.603940.
Pełny tekst źródłaLee-Thorp, Julia Anne. "Stable carbon isotopes in deep time : the diets of fossil fauna and hominids". Doctoral thesis, University of Cape Town, 1989. http://hdl.handle.net/11427/21732.
Pełny tekst źródłaThis thesis describes the development, testing and application of a technique for extending carbon isotopic dietary tracing millions of years in time,. using the mineral phase of calcified tissues (apatite) as alternative sample material to collagen. The results reported here provide empirical evidence for the validity of the technique. Investigation of the isotopic relationships between diet, collagen and apatite, using a large sample of modem fauna with known diets, confirms that the isotopic relationship between collagen and apatite changes with trophic level.
Le, Roux Debbie Jeanette. "Growth, water use efficiency and stable carbon isotopes in commercial clones of Eucalyptus". Master's thesis, University of Cape Town, 1993. http://hdl.handle.net/11427/18327.
Pełny tekst źródła