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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

Strain Concentrations in Polyethylene Geomembranes Adjacent to Seams and Scratches

January 2017 (has links)
abstract: Laboratory testing was conducted to quantify strain concentrations adjacent to seams and scratches in high density polyethylene (HDPE) geomembranes. The tensile strain profile of remnants meeting the ASTM criteria for wide-width tensile testing from samples of field seams recovered for construction quality assurance testing was evaluated using digital image correlation (DIC). Strains adjacent to scratches on laboratory prepared samples loaded in tension were also measured using DIC. The tensile strain in the zone adjacent to a seam and the tensile strain adjacent to a scratch were compared to the tensile strains calculated using theoretical strain concentration factors. The relationship between the maximum tensile strain adjacent to a seam and the global nominal strain in the sample was quantified for textured and smooth geomembranes of common thicknesses. Using statistical analysis of the data, bounds were developed for the allowable nominal tensile strain expected to induce maximum tensile strains adjacent to the seam less than or equal to the typical yield strain of HDPE geomembranes, at several confidence levels. Where nominal strain is the global or average strain applied to the sample and maximum strain is the largest tensile strain induced in the sample. The reduction in the nominal yield strain due to a scratch in a HDPE geomembrane was also quantified. The yield strain was approximately the same as predicted using theoretical strain concentration factors. The difference in the average measured maximum strains adjacent to the seams of textured and smooth HDPE geomembranes was found to be statistically insignificant. However, maximum strains adjacent to extrusion welded seams were somewhat greater than adjacent to fusion welded seams for nominal strains on the order of 3% to 4%. The results of the testing program suggest that the nominal tensile strain should be limited to 4% around dual hot wedge seams and 3% around extrusion fillet seams to avoid maximum strains equal to 11%, a typical yield strain for HDPE geomembranes. / Dissertation/Thesis / Masters Thesis Civil Engineering 2017
82

Traçadores isotópicos (Pb) e concentrações de metais em sedimentos superficiais: ferramentas na caracterização da poluição no setor oeste da baía de Sepetiba-RJ (SE do Brasil) / Isotopic tracers (Pb) and metal concentrations in surface sediments: tools for characterizing pollution in the west bay of Sepetiba-RJ (SE Brazil)

Shéron Joyce Díaz Morales 30 May 2012 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Este estudo teve como objetivo principal utilizar os teores de elementos-traço e análise isotópica de Pb (204Pb,206Pb,207Pb,208Pb) como ferramentas na caracterização da poluição da Baía de Sepetiba-RJ. As coletas de sedimento superficiais de fundo foram realizadas em três campanhas, em novembro de 2010, no setor oeste da Baía de Sepetiba RJ. A malha amostral é composta por 66 amostras (BSEP 001 a BSEP 066) coletadas com busca-fundo Van Veen. O pré-processamento das amostras ocorreu no Laboratório Geológico de Preparação de Amostras do Departamento de Geologia da Universidade do Estado do Rio de Janeiro. A digestão parcial das amostras de sedimento (< 0.072 mm) para obtenção do teor parcial dos elementos-traço (Ag, As, Cd, Co, Cr, Cu, Li, Mn, Ni, Pb, Sr, U, Zn) e de isótopo de Pb (lixiviação) foi executada no Laboratório de Geoquímica Analítica do Instituto de Geociências da UNICAMP e a leitura foi executada através do ICP-MS. Já as análises das concentrações totais dos elementos-traço (inclusive, Hg) e de isótopos de Pb (dissolução total) foram realizadas no laboratório ACTLABS (Ontário-Canadá) através do ICP Varian Vista. As leituras isotópicas foram feitas somente nas amostras que apresentaram concentrações parciais de Pb, acima de 0,5 g/g, totalizando 21 estações. Pôde-se constatar a existência de um enriquecimento de elementos-traço no setor oeste da Baía de Sepetiba. As médias dos teores totais de Ag (0,4 g/g), Cd (0,76 g/g), Cu (62,59 g/g), Li (43,29 g/g), Ni (16,65 g/g), Pb (20,08 g/g), Sr (389,64 g/g) e Zn (184,82 g/g) excederam os limites recomendados ou valores naturais. Isto pode ser reflexo da influência antrópica na região, principalmente relacionada à atividade de dragagem e à permanência dos resíduos de minério da desativada companhia de minério Ingá, na Ilha da Madeira. Os mapas de distribuição da concentração dos metais-traço destacaram a presença de vários sítios de deposição ao longo do setor oeste da baía de Sepetiba, com destaque para a região entre a porção centro oeste da Ilha de Itacuruça e o continente; Saco da Marambaia e Ponta da Pombeba; e porção oeste da Ponta da Marambaia. As razões isotópicas 206Pb/207Pb da área estudada variaram entre 1,163 a 1,259 para dissolução total e 1,1749-1,1877 para técnica de lixiviação, valores considerados como assinaturas de sedimentos pós-industriais ou comparados à assinatura de gasolina. Ainda sobre a técnica de lixiviação, destaca-se que os sedimentos superficiais do setor oeste (206Pb/207Pb: 1,1789) da baía de Sepetiba apresentaram uma assinatura uniforme e menos radiogênica do que setor leste (206Pb/207Pb: 1,2373 e 1,2110) desta baía. Através da assinatura isotópica de Pb encontrada nesta região é possível destacar a pouca contribuição das águas oceânicas para esse sistema, entretanto, a circulação interna intensa das águas da baía permite a homogeneização destas. O emprego destes tipos de ferramentas no monitoramento ambiental da área mostrou-se bastante eficiente, sendo importante a continuidade desta abordagem de pesquisa a fim de auxiliar na implementação de um plano de manejo local. / This study aimed to use of trace elements contents and isotopic analysis of Pb (204Pb, 206Pb, 207Pb, 208Pb) as tools to characterize the pollution of the Sepetiba Bay, Rio de Janeiro. Sampling of surface bottom sediments were carried out in three campaigns in November 2010, in the west sector of the Sepetiba Bay - RJ. The sampling grid is composed of 66 samples (BSEP 001 to BSEP 066) collected with Van Veen - bottom grab. The pre-processing of the samples occurred in the Geological Laboratory Sample Preparation, Department of Geology of the Rio de Janeiro State University. The partial digestion of sediments samples (< 0072 mm) to obtain the trace elements partial content (Ag, Cd, Co, Cr, Cu, Li, Mn, Ni, Pb, Sr, U, Zn) and Pb isotope (leaching) was performed at the Laboratory of Analytical Geochemistry of the Geosciences Institute at UNICAMP and the reading was performed by ICP-MS. The analysis of the total concentrations of trace elements (including, Hg) and Pb isotopes (total dissolution) were performed in the laboratory Actlabs (Ontario, Canada) by ICP Varian Vista. The isotopic readings were taken only in samples with partial Pb concentrations above 0,5 g/g, a total of 21 stations. It was found that the existence of an enrichment of trace elements in the west sector of the Sepetiba Bay. The mean total content of Ag (0,4 g/g), Cd (0,76 g/g), Cu (62,59 g/g), Li (43,29 g/g), Ni (16,65 g/g), Pb (20,08 g/g), Sr (389,64 g/g) and Zn (184,82 g/g) exceeded the recommended limits or natural values. This may reflect the anthropogenic influence in the region, mainly related to the activity of dredging and the permanence of waste ore off the mining company Inga, on the Madeira island. The distribution maps of the concentration of trace metals highlighted the presence of multiple sites of deposition along the west sector of Sepetiba Bay, with emphasis on the region between the central west of the Itacuruça Island and the mainland; Marambaia Bay and Pombeba Tip, and the west portion of Marambaia Bay. 206Pb/207Pb isotope ratios in the study area ranged from 1,163 to 1,259 for total dissolution and 1,1749 to 1,1877 for leaching technique values considered as a signature of postindustrial or sediments compared to the signature of gasoline. Still on the leaching technique, it is emphasized that the surface sediments of the west sector (206Pb/207Pb: 1,1789) from Sepetiba Bay presented a signature uniform and less radiogenic than the east sector (206Pb/207Pb: 1,2373 and 1,211) of this bay. Through the Pb isotopic signature found in this region is possible to highlight that there is minimal contribution of ocean water for this system, however, the intense internal circulation of the waters of the bay allows the homogenization of these. The use of these types of tools in environmental monitoring of the area proved to be very efficient, it is important to continue this research to assist in implementing a management plan for the site.
83

Concentrações naturais de elementos químicos da classe insecta do fragmento florestal de Mata Atlântica Reserva Charles Darwin

MAGALHÃES, Marcelo da Rocha Leão de 05 March 2015 (has links)
Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2016-07-20T14:53:39Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissetação completa final.pdf: 2106583 bytes, checksum: 7a10c40c5d1dfcf24e8d61371ccc92bd (MD5) / Made available in DSpace on 2016-07-20T14:53:39Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissetação completa final.pdf: 2106583 bytes, checksum: 7a10c40c5d1dfcf24e8d61371ccc92bd (MD5) Previous issue date: 2015-03-05 / FACEPE / Áreas naturais, assim como seus compartimentos ecológicos são, muitas vezes, negligenciados em estudos da qualidade ambiental. O compartimento insetos é extremamente importante devido sua representatividade nos ecossistemas e participação em praticamente todos os processos ecológicos mantenedores da biodiversidade. Estudos envolvendo a biomonitoração de elementos químicos são escassos no Brasil para este grupo de animais, principalmente pela inexistência de protocolos analíticos e padrões de referência para estudos ambientais. Neste trabalho, inicialmente foram avaliadas três metodologias de solubilização ácida de amostras de insetos, ou seja, o tratamento fraco (ácido nítrico a 50%), o tratamento I (ácido nítrico p.a. a 65%) e o tratamento II (ácido nítrico p.a. 65% e peróxido de hidrogênio a 35%). Após a definição do melhor procedimento de tratamento químico, as concentrações naturais de insetos foram estabelecidas para As, Cd, Cl, Cu, Fe, Mo, P, Pb, S, Sb, Th e Zn por meio das técnicas de Fluorescência de Raios-X por Energia Dispersiva (EDXRF), Espectrometria de Absorção Atômica com Forno de Grafite (GFAAS) e Espectrometria de Massas por Plasma Acoplado Indutivamente (ICP-MS). Para a garantia da qualidade do procedimento, foram utilizados os materiais de referência SRM 2976 Mussel tissue, RM 8415 Whole egg powder, SRM 1515 Apple leaves, RM 8414 Bovine muscle Powder, IAEA 336 Lichen e IAEA V-10 Hay Powder, produzidos pela Agência Internacional de Energia Atômica (IAEA) e o National Institute of Standards and Technology (NIST). Por meio deste estudo, comprovou-se a qualidade do procedimento analítico ao utilizar-se o método envolvendo HNO3 e H2O2 (tratamento II) para a solubilização das amostras de insetos e materiais de referência. Os resultados obtidos da análise quantitativa comprovaram a qualidade do procedimento analítico para a determinação de doze elementos químicos pelas técnicas analíticas empregadas. As regiões HPD foram obtidas em nível de 95% de confiança para as concentrações naturais médias de As, Cd, Cl, Cu, Fe, Mo, P, Pb, S, Sb, Th e Zn dos insetos terrestres do Refúgio Ecológico Charles Darwin, tendo resultados comparáveis àqueles de outros ecossistemas naturais. A análise estatística demonstrou a confiabilidade dos resultados obtidos para aplicação em estudos futuros referentes a insetos da Mata Atlântica de Pernambuco. / Natural areas, as well as its ecological compartments are often negligected in studies of environmental quality. The insects compartment is extremely important because of their representativeness on ecosystems and participation in almost all ecological processes for biodiversity maintaining. Studies involving biomonitoring of chemical elements are scarce in Brazil for this group of animals, especially by the absence of analytical protocols and reference standards for environmental studies. In this study, three approaches were initially evaluated of acid solubilization in insect samples, in other words, the weak treatment (50% nitric acid) treatment I (p.a. nitric acid at 65%) and treatment II (p. a. nitric acid 65 % and hydrogen peroxide 35%). After defining the best chemical treatment procedure, the natural concentrations of insects from the Refugio Ecológico Charles Darwin have been established for As, Cd, Cl, Cu, Fe, Mo, P, Pb, S, Sb, Zn and Th using Energy dispersive X-ray fluorescence (EDXRF), Graphite Furnace Atomic Absorption Spectrometry (GFAAS) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The reference materials SRM 2976 Mussel tissue, RM 84 15 Whole egg powder, SRM 1515 Apple leaves, RM 8414 Bovine muscle Powder, IAEA 336 Lichen and IAEA V-10 Hay Powder, produced by the International Atomic Energy Agency (IAEA) and the National Institute of Standards and Technology (NIST) were used to guarantee the quality of the analytical procedure. This study proved the quality of the analytical procedure when using the method involving HNO3 and H2O2 (treatment II) for solubilization of insects samples and reference materials. The results of the quantitative analysis confirmed the quality of an analytical procedure for determining the twelve chemicals used analytical techniques. The HPD regions were obtained in 95% level of confidence for the average natural concentrations of As, Cd, Cl, Cu, Fe, Mo, P, Pb, S, Sb, Th and Zn of terrestrial insects of the Refugio Ecológico Charles Darwin, having results comparable with those of other natural ecosystems. The statistical approach demonstrated the reliability of the obtained results for using in further studies on insects from the Atlantic Forest of Pernambuco, Brazil.
84

Interação solo-vegetação na avaliação de impactos ambientais em fragmento florestal de Mata Atlântica

SILVA NETO, Paulo Correia Da 04 August 2015 (has links)
Submitted by Irene Nascimento (irene.kessia@ufpe.br) on 2016-09-08T19:41:49Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertacao_Defesa_Paulo(cd).pdf: 5124321 bytes, checksum: 54f2d39f7c5ed9dbb73175b9a7d0cde3 (MD5) / Made available in DSpace on 2016-09-08T19:41:49Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertacao_Defesa_Paulo(cd).pdf: 5124321 bytes, checksum: 54f2d39f7c5ed9dbb73175b9a7d0cde3 (MD5) Previous issue date: 2015-08-04 / As atividades industriais e agrícolas contribuem para os mais complexos impactos ambientais e alteram a disponibilidade de elementos químicos para os produtores primários que, por sua vez, promovem a acumulação de substâncias na teia alimentar. Desse modo, é essencial a compreensão dos efeitos e distribuição de elementos químicos que tenham sido liberados direta ou indiretamente pelas atividades antrópicas ou naturais e incorporados por processos ecológicos nos ecossistemas, principalmente unidades de conservação. O objetivo desse trabalho foi caracterizar o solo e a vegetação do fragmento de Mata Atlântica Refúgio Ecológico Charles Darwin para avaliação da transferência de elementos químicos no ecossistema. Folhas de árvores nativas e exóticas foram coletadas, assim como o solo na profundidade de 0-15 cm sob a projeção das copas das árvores. Todas as amostras foram secas em estufa à 60ºC com conseguinte redução do tamanho de partículas (< 0,5 mm) em almofariz de porcelana para o material geológico, enquanto que o material biológico foi cominuido utilizando-se de moinho com lâminas de titânio para evitar contaminação com elementos químicos metálicos. Concentrações de Al, Ba, Br, Ca, Cd, Cu, Fe, K, Mn, P, Sb, Si, Sr, Ti, Th, U e Zn, assim como concentrações de atividade de 40K, 214Pb, 214Bi e 228Ac, foram determinadas nos solos do Refúgio Ecológico Charles Darwin. Todavia, apenas Al, Ca, Cd, Cl, Cu, Fe, K, Mg, P, S, Sb, Sr, Th, U e Zn foram quantificados nas folhas de árvores, possibilitando avaliar a transferência no sistema solo-vegetação para os elementos químicos Al, Ca, Cd, Cu, Fe, Th, U e Zn. Os resultados indicaram acumulação considerável na vegetação da unidade de conservação de alguns elementos químicos, contudo, a espécie Pachira aquatica acumulou principalmente Ca nas folhas. Tal fenômeno pode ter implicações ecológicas com relação à disponibilidade deste elemento químico. Além disso, essa espécie é considerada invasora. Mesmo assim, plena caracterização de elementos químicos foi realizada na unidade conservação, proporcionando valores indicativos para futuros estudos ambientais da Mata Atlântica de Pernambuco. / The industrial and agricultural activities contribute to the most complex environmental impacts and alter the availability of chemical elements for primary producers, in which accumulated substances in the food web. Therefore, it is essential to understand the effects and distribution of chemical elements that have been direct or indirectly released by anthropogenic or natural activities and incorporate by ecological processes in ecosystems, mainly conservation units. The objective of this study was to characterize the soil and the vegetation of the Atlantic Forest fragment Refúgio Ecológico Charles Darwin for the evaluation of the chemical element transfer in the ecosystem. Exotic and native tree leaves were collected, as well as the 0-15 cm depth soil under tree crown projection. All samples were oven-dried at 60 °C with consequent reduction of the particle size (<0.5 mm) in porcelain mortar for geological material, while the biological material was comminuted using titanium mill for preventing metallic contamination. Concentrations of Al, Ba, Br, Ca, Cd, Cu, Fe, K, Mn, P, Sb, Si, Sr, Ti, Th, U and Zn, as well as activity concentrations of 40K, 214Pb, 214Bi and 228Ac, were determined in the Refúgio Ecológico Charles Darwin soils. Nevertheless, only Al, Ca, Cd, Cl, Cu, Fe, K, Mg, P, S, Sb, Sr, Th, U and Zn were quantified in the tree leaves, thereby assessing the soil-vegetation system transfer for the chemical elements Al, Ca, Cd, Cu, Fe, Th, U and Zn. The results indicated considerable accumulation in the conservation unit vegetation of some chemical elements, however, the species Pachira aquatica mainly accumulated Ca in the leaves. Such phenomenon might cause ecological implications related to the Ca availability. Besides, this species is considered invasive. Even though, a full characterization of chemical elements was carried out in conservation unit, providing indicative values for further environmental studies in the Pernambuco Atlantic Forest.
85

Determinação da concentração de entrada dos gases de efeito estufa na Costa Norte/Nordeste brasileira / Determination of the background greenhouse gases concentrations in Amazon basin

Viviane Francisca Borges 12 November 2013 (has links)
Este estudo teve como objetivo a determinação da concentração de entrada dos Gases de Efeito Estufa (GEE) no ar proveniente do Oceano Atlântico na região norte/nordeste da costa brasileira e o entendimento da origem destas massas de ar e o padrão circulatório e sua sazonalidade. Esta parte do litoral corresponde à área em que as massas de ar adentram no continente, antes de chegar à Bacia Amazônica. Em 2010 foram iniciados estudos em dois locais na costa, Salinópolis, no estado do Pará e Natal, no Rio Grande do Norte. Amostras de ar foram coletadas em superfície semanalmente e foram analisadas no Laboratório de Química Atmosférica do IPEN, quantificando-se os gases: dióxido de carbono (CO2), metano (CH4), óxido nitroso (N2O), hexafluoreto de enxofre (SF6) e monóxido de carbono (CO). Os resultados obtidos mostraram que Salinópolis (SAL) apresenta maior sazonalidade, entre as estações climáticas, quando comparada a Natal (NAT), sendo essa observação confirmada pelas trajetórias retrocedentes das massas de ar, para cada local de estudo. Observou-se que SAL recebe massas de ar, tanto do Oceano Atlântico Norte, como do Sul (dependendo da época do ano), e em NAT, as massas de ar são originárias apenas do Oceano Atlântico Sul. Este comportamento está relacionado com a zona de convergência intertropical. Os resultados de uma maneira geral mostram a ocorrência de um crescimento nas concentrações médias obtidas em SAL e NAT com o passar dos anos, acompanhando o crescimento mundial. A concentração média para o principal GEE, CO2, em SAL nos anos de 2010, 2011 e 2012 foi de 388,01, 390,39 e 392,14 ppm, respectivamente, e em NAT foi de 388,59, 389,65 e 392,59 ppm respectivamente. / This study had the objective to determinate the background concentrations of Greenhouse Gases in the air from Atlantic Ocean in the north/northeast region of the Brazilian coast and understanding the origin of these air masses and circulatory pattern and seasonality. This region of the coast corresponds to the zone where the air masses pass through before to arrive in Amazon Basin. Studies were started in 2010, in two sites of the coast, Salinópolis in Pará state and Natal in Rio Grande do Norte state. The air samplings were performed on the surface weekly and analysed in the Atmospheric Chemistry Laboratory of IPEN, quantifying concentrations of the gases: Carbon dioxide (CO2), Methane (CH4), Nitrous oxide (N2O), Sulfur hexafluoride (SF6) and Carbon monoxide (CO). The obtained results showed that Salinópolis (SAL) have higher seasonality, among climatic seasons, in comparison to Natal (NAT), being this observation confirmed by backward trajectories of air masses to each studied site. SAL received air masses from the North and South Atlantic Ocean, and NAT the air masses arrived only from the South Atlantic Ocean. This behavior, is related with the intertropical convergence zone position. The results, in general, showed an increase of mean GHG concentrations in SAL and NAT along the years, following global growth. The mean concentration of the main GHG, CO2, in SAL to 2010, 2011 and 2012 was 388.01, 390.39 and 392.14 ppm, respectively, and in NAT it was 388.59, 389.65 e 392.59 ppm, respectively.
86

Environmental impact of heavy metal pollution in natural aquatic systems

Tayab, Muhammad Rehan January 1991 (has links)
The distribution of heavy metals between soil and soil solutions is a key issue in evaluating the environmental impact of long term applications of heavy metals to land. Contamination of soils by heavy metals has been reported by many workers. Metal adsorption is affected by many factors, including soil pH, clay mineralogy, abundance of oxides and organic matter, soil composition and solution ionic strength. The pH is one of the many factors affecting mobility of heavy metals in soils and it is likely to be the most easily managed and the most significant. To provide the appropriate level of protection for aquatic life and other uses of the resource, it is important to be able to predict the environmental distribution of important metals on spatial and temporal scales and to do so with particular emphasis on the water column concentrations. Regulatory levels reflected in water quality criteria or standards are based on water column concentrations. Predicting water column concentrations requires a consideration of the interactions of water column contaminants with both bed sediments and suspended particulates as critical components in the assessment. The adsorption behaviour of cadmium, copper, lead and zinc onto soils is studied under the various geo-environmental conditions of pH, concentration of adsorbate and adsorbent, and solution compositions. Experiments were conducted to determine the equilibrium contact time of various adsorbates for adsorbent in different systems. Experiments were also conducted to check the efficiency of various acid-mixtures to extract heavy metal from soils into the aqueous phase. The adsorption behaviour of heavy metals onto soils was also studied from sea-water system. Soils are characterized in terms of the role of clay minerals to remove the metals from the solution phase, back-ground levels of metals, maximum adsorption capacity to adsorb various heavy metals from different adsorption systems, and type of surface sites present. The experimental data of metal adsorption is described by Langmuir adsorption model. The adsorption data are also expressed in terms of surface loading, surface acidity, adsorption density, and affinity of soils for heavy metals in different adsorption systems. Ecological implications of changes in physical and chemical conditions in aquatic systems on heavy metals uptake by soils are also discussed. This research covers the following areas: the environmental impact of heavy metal discharge into the aquatic systems, the study of the mobility patterns of different heavy metals as function of geo-environmental conditions, and determination of the pathways and the ultimate fate of heavy metals in the environment.
87

Determination of kanamycin plasma concentrations using LC/MS and pharmacokinetics of kanamycin in patients with multidrug-resistant tuberculosis and in patients with multidrug-resistant tuberculosis co-infected with HIV

Abaniwonda, Ibukunoluwa Mercy January 2012 (has links)
Magister Pharmaceuticae - MPharm / The aim of the study was to determine firstly, kanamycin plasma concentrations using liquid chromatography coupled with mass spectrometry (LC/MS); secondly, to investigate the PK parameters of kanamycin in patients infected with MDR-TB and in patients co-infected with MDR-TB and HIV; thirdly, to assess the influence of HIV infection and renal impairment on the PK of kanamycin and fourthly, to find out whether there is any interaction between antiretroviral drugs and kanamycin.
88

Lake condition changes of a boreal lake over the past ca. 6500 years based on varve geochemistry

Ligtenberg, Jora January 2017 (has links)
The purpose of this study was to assess changes in the in-lake conditions of lake Kassjön, northern Sweden, in response to environmental and climate changes over the past ca. 6500 years. Sediment concentrations of different elements and biogenic silica (bSi) were measured with wavelength dispersive X-ray fluorescence spectrometry (XRF) and Fourier transform infrared spectroscopy (FTIR), respectively. The lake-water total organic carbon (LWTOC) content was inferred based on near-infrared spectroscopy (NIRS). The marine sediment was distinguished from the lacustrine sediment by higher dry bulk density, lithogenic element concentrations and Br content, and lower bSi concentrations. After lake formation, the dry bulk density, lithogenic element concentrations and metal contents decreased, while organic matter (OM), bSi and LWTOC increased. The main reasons for these changes are soil development and vegetation establishment. Spruce immigration around 3000 BP induced considerable changes to the sediment concentrations indicative of increased erosion versus weathering, and LWTOC declined. These changes are mainly related the different characteristics of spruce compared to birch. Human influences in the catchment were also clearly visible, but the rest of the sediment sequence demonstrated that natural changes can be of a similar magnitude. Overall, relatively small-scale, catchment specific processes seem to be more important for changes in the lake conditions than general climate change.
89

Changes in Cell Free DNA Concentrations during the Course of a Collegiate Soccer Season

Gentles, Jeremy A., Hornsby, W. Guy, Gray, H. S., MacDonald, C. J., Miller, Jane A., Coniglio, C. L., Dotterweich, Andy R., Stuart, Charles A., Sands, William A., Stone, Michael H. 01 January 2014 (has links)
This study investigated chronic changes in cell free DNA (cf-DNA) and other biochemical markers throughout a college soccer season. Twenty three NCAA Division I male collegiate soccer players volunteered to participate in this study. Athletes were divided into two groups based upon their weekly average game time rating of session rating of perceived exertion (sRPE). Group 1 (G1, n = 13, age 21.7 ± 1.5 years, height 178.8 ± 6.9 cm, body mass 77.9 ± 6.5 kg), consisted mostly of starters, averaged greater than a weekly 1500 game time sRPE over a fifteen week Fall season. Group 2 (G2, n =10, age 20.6 ± 1.0 years, height 181.8 ± 7.4 cm, body mass 82.5 ± 10.5 kg) averaged less than 1500 game time sRPE. Venous blood samples were taken three times; preseason, approximately midseason and postseason. In G1, cf-DNA (P = 0.001), CRP (P = 0.000), CK (P = 0.003), cf-DNA %∆ (P = 0.002), CRP %∆ (P = 0.002), CK %∆ (P = 0.002) were all significantly higher than T1 at T2 and T3. In G2, CRP %∆ (P = 0.039) was significantly higher at T2 than T1. Despite the lack of statistically significant differences across all three testing times, cf-DNA %∆, CRP %∆ and CK %∆ increased throughout the season in G1. In G2, cf-DNA %∆, CRP %∆ and CK %∆ were all higher at T2 and T3 than T1 but fewer significant differences were present. This may suggest that cf-DNA is a useful marker to reflect accumulated soccer training and competitive stressors.
90

Distribution of Nighttime F-region Molecular Ion Concentrations and 6300 Å Nightglow Morphology

Brasher, William Ernest, 1939- 12 1900 (has links)
The purpose of this study is two-fold. The first is to determine the dependence of the molecular ion profiles on the various ionospheric and atmospheric parameters that affect their distributions. The second is to demonstrate the correlation of specific ionospheric parameters with 6300 Å nightglow intensity during periods of magnetically quiet and disturbed conditions.

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