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A Survey of the Occurence of Oxygen 18 in Natural SourcesVrooman, Ransom H. 10 1900 (has links)
An investigation of the concentration of the heavy isotope
of oxygen, O18, in various samples of water was carried out. Natural
variations as high as 2.9% were found - glacier water being 2.3%
light and Dead Sea water 2.0% heavy, as compared to Lake Ontario water
as standard. Other values - water from tank oxygen + 2.9%, atmospheric
water vapor -0.9%, Atlantic Ocean water +0.4%, Pacific Ocean water
- 0.8% , and atmospheric carbon dioxide - 0.5%. The water samples were
equilibrated with tank carbon dioxide, which was then analyzed using
the mass spectrometer. Some work was also done on photosynthesis.
The free water, water of crystallization, and tissue oxygen (as water) ,
in a normal leaf which had bean photosynthesizing for 8 hours, were
analyzed by equilibration with carbon dioxide as above. It was found
that all of these were more enriched in oxygen 18 than the water with
which they were fed . The free water averaged about 1.3% heavy, water
of crystallization as high as 8.7% heavy, and tissue oxygen varied from
0.5% light to 5.5% heavy. This work only just touches the edges of this
field - many more interesting experiments remain to be carried out later. / Thesis / Master of Science (MS)
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Fracionamento isotopico da agua durante a evaporacaoSANTIAGO, MARIA M.F. 09 October 2014 (has links)
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01035.pdf: 2590190 bytes, checksum: 1d1815b8298ea5a3e4f29d7bf0ea2239 (MD5) / Dissertacao (Mestrado) / IEA/D / Escola Politecnica, Universidade de Sao Paulo - POLI/USP
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Fracionamento isotopico da agua durante a evaporacaoSANTIAGO, MARIA M.F. 09 October 2014 (has links)
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01035.pdf: 2590190 bytes, checksum: 1d1815b8298ea5a3e4f29d7bf0ea2239 (MD5) / Dissertacao (Mestrado) / IEA/D / Escola Politecnica, Universidade de Sao Paulo - POLI/USP
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An evaluation of the use of natural stable isotopes of water to track water movement through oil sands mine closure landforms2014 March 1900 (has links)
Surface mining of oil sands results in extensive land disturbance, earth movement and water usage. After mining, the disturbed landscapes must be reconstructed and reclaimed as natural landforms. There are numerous challenges associated with understanding the responses of these landforms over time, including a need to track and characterize water movement through closure landforms to understand the hydrological responses of these landforms over time. This study attempted to use natural stable isotopes of water (δD and δ18O) to identify and characterize source waters from various closure landforms at an oil sands mine site.
The study area is Syncrude‟s Mildred Lake mine, an open pit oil sands mine located in northern Alberta. A variety of groundwater, surface water and soil samples from a variety of landforms (overburden dumps, composite and mature fine tailings areas, tailings sand structures and freshwater reservoirs) were collected in an attempt to fully represent the isotopic distribution of waters across the mine site. Laboratory analysis of δD and δ18O was done on all samples.
The local meteoric water line first established by Hilderman (2011) was redeveloped with additional precipitation data and calculated to be δD=7.0(δ18O) -18.6‰. A natural evaporation line having a slope of 5.3 was calculated for the mine site with samples collected from three surface water ponds on the mine site.
Five primary source waters were identified on the mine site: process affected water/tailings, rainfall, snow, interstitial shale water and Mildred Lake water. It was found that these sources of water generally have unique natural stable water isotope signatures. Process affected water at the site generally had an enriched signature compared to other mine waters. The enrichment was attributed to fractionation from the recycle water circuit and natural evaporation.
The characterizations of these source waters were then used in several hydrogeological examples to demonstrate that natural stable water isotopes can be applied to water balance estimates and to identify water movement processes related to closure landforms.
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Diferentes fluidos corporais, intervalos de amostragem e efeito do sexo na aplicação do método da água duplamente marcada em gatos /Goloni, Camila. January 2018 (has links)
Orientador: Aulus Cavalieri Carciofi / Resumo: O gasto energético diário (GED) de gatos tem sido estudado há algum tempo em gatos de laboratório, com ambiente, alimentação e massa corporal controlados. O metabolismo energético destes animais pode ser dividido em quatro compartimentos: taxa metabólica basal que soma o maior GED destes animais em torno de 60%, a atividade muscular voluntária contribuindo em torno de 30%, seguido do incremento calórico e termogênese adaptativa (10%). Nota-se que a atividade muscular voluntária contribui com porção considerável do GED destes animais, não devendo ser limitada, pois interfere diretamente no gasto energético. Estudos com animais em domicílio, com número representativo de grandes populações, que apresentam rotina de vida normal com protocolo prático e eficaz, de fácil aceitação pelos proprietários para mensurar GE, composição corporal (CC) e fluxo de água (FA) no estilo de vida habitual de gatos é importante para estudos nutricionais mais precisos. Método prático e eficaz para mensuração destes parâmetros, de fácil aplicação em domicílio e que não interfira no estilo de vida e atividade física dos animais é o método da água duplamente marcada que os mensura por meio do enriquecimento e decaimento de deutério (2H) e oxigênio 18 (18O) na água corporal. O objetivo do presente trabalho foi avaliar protocolo prático de tempos de coleta de enriquecimento (2, 4, 6, 7 e 8 horas) e decaimento (2, 4, 6, 8, 10, 12, 14, 16, 18 e 20 dias), bem como os fluidos corporais alternativos saliva e u... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The energy expenditure (EE) of cats has been studied for some time in laboratory cats, with controlled environment, feeding and body mass. The energy metabolism of these animals can be divided into four compartments: basal metabolic rate that sums the highest EE of these animals around 60%, voluntary muscle activity contributing around 30%, followed by caloric increment and adaptive thermogenesis (10%). It is noted that voluntary muscle activity contributes a considerable portion of the EE of these animals, and should not be limited, as it directly interferes with energy expenditure. Studies with animals at home, with a representative number of large populations, that present normal life routine with a practical and efficient protocol, easily accepted by the owners to measure EE, body composition (BC) and water turnover (WT) in lifestyle of cats is important for more accurate nutritional studies. A practical and effective method for measuring these parameters, which is easy to apply at home and does not interfere with the animals' lifestyle and physical activity, is the double labeled water method that measures them through the enrichment and decay of deuterium (2H) and oxygen 18 ( 18O) in body water. The aim of the present study was to evaluate the practical protocol of enrichment collection times (2, 4, 6, 7 and 8 hours) and decay (2, 4, 6, 8, 10, 12, 14, 16, 18 and 20 days ) as well as alternative body fluids saliva and urine compared to blood for assessing the concentrati... (Complete abstract click electronic access below) / Mestre
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Contribuicao ao estudo da evaporacao de aguas naturais por meio de isotopos estaveisTAKAKI, T. 09 October 2014 (has links)
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00385.pdf: 917455 bytes, checksum: 170691f120f1bd5b66fa48cba02fe1f6 (MD5) / Dissertacao (Mestrado) / IEA/D / Escola Politecnica, Universidade de Sao Paulo - POLI/USP
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Contribuicao ao estudo da evaporacao de aguas naturais por meio de isotopos estaveisTAKAKI, T. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:50:42Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:59:03Z (GMT). No. of bitstreams: 1
00385.pdf: 917455 bytes, checksum: 170691f120f1bd5b66fa48cba02fe1f6 (MD5) / Dissertacao (Mestrado) / IEA/D / Escola Politecnica, Universidade de Sao Paulo - POLI/USP
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Mobility and Collapse: Stable Isotope Analysis of Oxygen-18 Isotopes from Ancient MexicoSt. Pierre, Melanie L 01 January 2018 (has links)
When a society experiences a collapse, political authority becomes decentralized, large settlements often become abandoned, economic specialization decreases; and monumental building projects, artistic, and literary achievements slow drastically. The Rio Verde Valley, a coastal floodplain located in the region of Oaxaca in Southwest Mexico, experienced such a collapse at the end of the Terminal Formative period (150 BC to 250 AD). A period of decentralization followed, with regional centers becoming the main seats of authority throughout the region. My aim is to understand how this collapse affected residential population mobility in the lower Rio Verde Valley between the pre-collapse Terminal Formative and post-collapse Early Classic periods. I seek to answer the question: could this political collapse have caused intra-regional migration amongst the people of Ancient Oaxaca? To answer this, I analyzed the stable 18O and 13O isotopes in a set of 21 samples of human long bone excavated from the Terminal Formative archaeological site of Yugüe and the Early Classic site of Charco Redondo. Oxygen isotope analysis is based on the principle that bone apatite and tooth enamel hold traces of oxygen isotopes found in the water that people drink, and that varying values of those isotopes reflect that the water was obtained from different sources. Based on literature surrounding the process of political collapse in ancient Mesoamerica and beyond, I expected to find evidence that intra-regional population mobility increased after the Terminal Formative period collapse. Instead, I found evidence of little to no mobility in both the Terminal Formative period site and the Early Classic period site, showing that the political collapse likely did not affect intra-regional mobility. These findings provide valuable insight into how human migration patterns correspond with political changes, both in the archaeological record of past civilizations and in modern societies.
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Stable Isotopes of Sulphur and Oxygen in Forested Catchments: Insight from New Techniques into Sulphur Cycling and Dissolved Organic Matter AlterationHumphries, Stefan January 2003 (has links)
Dissolved organic matter (DOM) is present in all forested catchments and can be important in binding metals, absorbing UV, and the transport of nutrients (C, N, S, P). DOM is extremely heterogeneous in time and space, making it difficult to characterize. New techniques have been developed to determine δ34S and δ18O in DOM. These techniques have been applied to samples from Harp and Plastic Lake catchments (45??23'N, 79?? 08'W, 45??11'N, 78?? 50'W) in order to obtain information about sources and sinks of DOM within forested catchments on the Canadian Shield. In conjunction with sulphate and DOC concentrations, this new data provides valuable insight into sulphur cycling and DOM alteration within these catchments. Data generated for δ34S-DOM and δ18O-DOM appears to be the first data reported in the literature for DOM.
The inorganic (δ34S-SO42-) and organic S (δ34S-DOM) differs by environment in both catchments. The range of δ34S-SO42- is between 3. 3‰ and 10. 3‰, and the range of δ34S-DOM is from 3. 4‰ to 8. 7‰. Sulphate in the Harp Lake catchment in most samples is subject to some sort of cycling within the watershed, since δ34S-SO42- differs from precipitation. In the Harp Lake catchment, upland δ34S-SO42- is influenced by historical precipitation. The δ34S-DOM is derived from leaching and microbial activity of DOM from organic horizons in the soil. The δ34S-SO42- and δ34S-DOM of wetland streams is extremely variable, controlled by hydrology. The δ34S-SO42- provides information on oxidation-reduction dynamics in the wetland, and δ34S-DOM provides information about sources of DOS in the wetland. The δ34S-SO42- and δ34S-DOM are possibly related in Harp Lake. Mineralization of DOS as evidenced by δ34S-DOM and DOS concentrations could be a small input of SO42- into Harp Lake.
It is possible δ18O-DOM could be an indicator of DOM alteration. The range of δ18O-DOM is between 8. 2‰ and 14. 4‰. The δ18O-DOM in the Harp Lake catchment is highly correlated with relative molecular weight, which has been shown to decrease with increasing alteration. Wetland streams show the largest range in δ18O-DOM, while uplands, groundwater, and Harp Lake are the least varied. The highest δ18O-DOM values are from sources of DOM such as leaf leachates (representative of forest floor litter) and wetlands. The most depleted samples are from groundwater and Harp Lake which typically contain highly altered DOM.
The δ34S-DOM and δ18O-DOM can provide valuable information on sources of DOM and DOM alteration within the catchment. The δ18O-DOM could also allow the separation of autochthonous and allochthonous DOM in lakes.
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Stable Isotopes of Sulphur and Oxygen in Forested Catchments: Insight from New Techniques into Sulphur Cycling and Dissolved Organic Matter AlterationHumphries, Stefan January 2003 (has links)
Dissolved organic matter (DOM) is present in all forested catchments and can be important in binding metals, absorbing UV, and the transport of nutrients (C, N, S, P). DOM is extremely heterogeneous in time and space, making it difficult to characterize. New techniques have been developed to determine δ34S and δ18O in DOM. These techniques have been applied to samples from Harp and Plastic Lake catchments (45º23'N, 79º 08'W, 45º11'N, 78º 50'W) in order to obtain information about sources and sinks of DOM within forested catchments on the Canadian Shield. In conjunction with sulphate and DOC concentrations, this new data provides valuable insight into sulphur cycling and DOM alteration within these catchments. Data generated for δ34S-DOM and δ18O-DOM appears to be the first data reported in the literature for DOM.
The inorganic (δ34S-SO42-) and organic S (δ34S-DOM) differs by environment in both catchments. The range of δ34S-SO42- is between 3. 3‰ and 10. 3‰, and the range of δ34S-DOM is from 3. 4‰ to 8. 7‰. Sulphate in the Harp Lake catchment in most samples is subject to some sort of cycling within the watershed, since δ34S-SO42- differs from precipitation. In the Harp Lake catchment, upland δ34S-SO42- is influenced by historical precipitation. The δ34S-DOM is derived from leaching and microbial activity of DOM from organic horizons in the soil. The δ34S-SO42- and δ34S-DOM of wetland streams is extremely variable, controlled by hydrology. The δ34S-SO42- provides information on oxidation-reduction dynamics in the wetland, and δ34S-DOM provides information about sources of DOS in the wetland. The δ34S-SO42- and δ34S-DOM are possibly related in Harp Lake. Mineralization of DOS as evidenced by δ34S-DOM and DOS concentrations could be a small input of SO42- into Harp Lake.
It is possible δ18O-DOM could be an indicator of DOM alteration. The range of δ18O-DOM is between 8. 2‰ and 14. 4‰. The δ18O-DOM in the Harp Lake catchment is highly correlated with relative molecular weight, which has been shown to decrease with increasing alteration. Wetland streams show the largest range in δ18O-DOM, while uplands, groundwater, and Harp Lake are the least varied. The highest δ18O-DOM values are from sources of DOM such as leaf leachates (representative of forest floor litter) and wetlands. The most depleted samples are from groundwater and Harp Lake which typically contain highly altered DOM.
The δ34S-DOM and δ18O-DOM can provide valuable information on sources of DOM and DOM alteration within the catchment. The δ18O-DOM could also allow the separation of autochthonous and allochthonous DOM in lakes.
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