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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.
121

Analysis and modifications of two in vivo methods for determining fluorine content in bone

Stuive, Rachel Monique January 2018 (has links)
Non-invasive techniques to measure bone fluorine levels in vivo are few and not well studied. These techniques would prove useful for longitudinal studies of fluorine accumulation and treatment optimization for patients with poor bone health. Two measurement techniques were analyzed and improvements to each technique attempted with bone samples and bone-mimicking phantoms. The first method analyzed was neutron activation analysis (NAA), a technique previously studied in our laboratory. A previous detector setup consisting of nine sodium iodide detectors was re-tested and a new detector setup consisting of two high-purity germanium detectors was also tested. The detection limit of the sodium iodide setup was found to be higher than previously reported by a factor of 4, and the new high-purity germanium detector setup was found to result in a higher detection limit by a factor of 5 compared to the sodium iodide setup. The second method analyzed was nuclear magnetic resonance (NMR). Magic angle spinning was performed on a human bone sample, and a novel probe was constructed for future in vivo measurements. MAS NMR measurement of the human bone sample showed it to have an appropriate chemical shift and shape consistent with previous research on substances similar to bone. The constructed probe successfully resonated at the appropriate frequency, however there were potential contamination problems which prevented a measurable fluorine signal from being obtained. Both the NAA and NMR techniques may be optimized further, though with the results obtained, NAA remains the more sensitive technique for measuring bone fluorine in vivo. / Thesis / Master of Science (MSc) / Fluorine is an element which accumulates in bones and teeth. High levels of fluorine have been shown to be unhealthy, causing both dental and skeletal fluorosis. Low levels of fluorine have been shown to reduce dental cavities, however, their effect on bone health is not well understood. Currently, fluorine can be measured in bone samples from either biopsies or cadavers. Having a non-invasive way to measure fluorine concentrations in living humans without the need for surgery would be invaluable. These measurements could be used to optimize treatment for osteoporosis patients or to determine if emergency measures are necessary in cases of high accidental doses to members of the public. Additionally, long-term studies examining fluorine metabolism and bone health could be performed on population groups of interest. For these reasons, two different non-invasive methods for determining fluorine content in bone were analyzed and enhancements to each measurement technique attempted.
122

Design, construction, and characterization of a neutron depth profiling facility at the Oregon State University TRIGA�� reactor with an advanced digital spectroscopy system

Robinson, Joshua A. 13 July 2012 (has links)
In this work, Neutron Depth Profiling (NDP) analysis capability has been added to the Oregon State University TRIGA�� Reactor Prompt Gamma Neutron Activation Analysis Facility (PGNAA). This system has been implemented with an advanced digital spectroscopy system and is capable of rise time pulse shape analysis as well as coincidence measurements from multiple detectors. The digital spectroscopy system utilizes a high-speed multichannel digitizer with speeds up to 200 Megasamples/second (MS/s) with advanced hardware trigger and time stamping capabilities. These additions allow the facility to conduct simultaneous NDP and PGNAA combined measurements, which also enables cross calibration. The digital pulse processing is implemented with software programmed rise time pulse shape analysis capabilities for the analysis of the detector responses on a pulse-by-pulse basis to distinguish between different interactions in the detector. The advanced trigger capabilities of the digitizer were configured to accurately measure and correct for dead time effects from pulse pile up and preamplifier decay time. / Graduation date: 2013
123

Development of a monoclonal antibody-based immunoradiometric assay for the measurement of the free alpha-subunit of human chorionic gonadotrophin.

Haneef, Raazia Be. January 1990 (has links)
Almost a century has elapsed since the antigen-antibody interaction was first recognised as the basis of an immune response (Ehrlich, 1897). However, it was only in the 1930s, with the development of improved technologies that this concept was better understood, and led to the discovery of the amazing diversity and specificity of antibody molecules (Landsteiner, 1933). Theoretically, it is possible to make antibodies to a variety of biological substances and other chemicals, and therefore they are ideally suited as specific recognition elements to be used for analytical, cytological, functional, therapeutic and biochemical purposes. The development of the radioimmunoassay (RIA) thirty five years ago, revolutionised research in many areas of clinical and scientific investigation. This technique evolved rapidly from the discovery made by Berson et al. in 1956 that antibodies to insulin could be detected in patients treated with this hormone, by measuring the binding of radiolabeled insulin to these antibodies. Although in the past RIAs have been the most important assay system employing antibody and labelled tracer, the limitation was that reliance had to be placed on the chance development of a good polyclonal antibody. These shortcomings stimulated the search for monospecific antibodies of reproducible quality and sufficient quantity. The development and introduction of monoclonal antibody technology brought about a revolution in immune serology (Kohler and Milstein, 1975). Establishment of immortal cell lines which contained the genetic elements of antibody-producing cells was achieved by fusion between a myeloma cell line and spleen cells from an immunised donor. The resulting hybrids had the essential properties of both parents, namely, permanent growth and a high capacity for the synthesis and secretion of immunoglobulins, normally characteristics of plasmacytomas, together with the genetic elements defining a specific antibody. Gestational trophoblastic disease (GTD) is a neoplastic condition of the trophoblast and occurs as molar pregnancy in a benign or invasive form, or as choriocarcinoma in a malignant form. Effective therapy has been developed for the treatment of both choriocarcinoma and molar pregnancy, but the key to successful management of these patients lies in their prompt diagnosis and careful monitoring of response to treatment (Green-Thompson, 1986). Fortuitously, these tumours elaborate the human chorionic gonadotrophin hormone (hCG) and its free alpha (a) and beta (B) subunits and hence a ready marker for the tumour exists. Human chorionic gonadotrophin is one of a group of glycoprotein hormones, which includes luteinising hormone (LH), follicle stimulating hormone (FSH) and thyroid stimulating hormone (TSH). These hormones are composed of two dissimilar subunits designated a and B, which are bound non-covalently in the intact molecule. The B-subunit of each glycoprotein hormone is unique and is responsible for the respective biological and immunological properties of the glycoproteins. In contrast, all four hormones possess an identical a-subunit which is coded for by a single gene (Fiddes and Goodman, 1979). The measurement of hCG and its free B-subunit, as so-called BhCG, for the diagnosis and monitoring of therapy in patients with GTD is now routinely practised throughout the world (Vaitukaitis et al., 1972). However it has been demonstrated by Bagshawe (1975) that when serum BhCG can no longer be measured by current RIA methods, up to 10" tumour cells may remain undetected. In addition, there have been isolated reports of two patients with choriocarcinoma in whom BhCG was undetectable in the serum but who appeared to be secreting only the a-subunit (Dawood et al, 1977). Furthermore, it has been suggested that measurement of free a-subunit rather than intact hCG or the free B-subunit is a more effective means of detecting persistent trophoblastic disease as well as tumour recurrence following treatment (Quigley et al, 1980a and b). Radioimmunoassays which measure the free a-subunit of hCG have been developed, but in general lack the specificity and sensitivity required (Gaspard et al, 1980; Kohorn et al, 1981). These assays employ polyclonal antisera which also detect epitopes common to the pituitary gonadotrophins. Thus there is a need to produce monoclonal antibodies which recognise regions of the free a-subunit which are hidden in the intact gonadotrophins. Such antibodies would provide the required specificity for use in RIAs but are limited in their use by their inherent lack of high affinity for the antigen. Fortunately, this drawback may be overcome by using monoclonal antibodies as labelled reagents in an alternative assay system, the immunoradiometric assay (IRMA), described by Miles and Hales (1968). The IRMA, particularly the two-site sandwich version of the assay, has been shown to provide greater sensitivity in addition to allowing enhanced specificity. This is a consequence of the use of two antibodies in excess to detect the analyte, each directed at a different epitope on the target molecule. The first antibody, referred to as the capture antibody, is usually linked to a solid-phase to facilitate easy separation and is added in excess relative to the target hormone to enhance antibody-antigen interaction, thereby allowing increased sensitivity in the measurement of analyte. The second antibody, referred to as the detection antibody, is labelled with a radioactive isotope or an enzyme to detect antigen already bound to the capture antibody. The application of monoclonal antibodies specific for the free a-subunit to a highly sensitive IRMA format is an obvious need. Hence this study was undertaken firstly, to raise and characterise monoclonal antibodies to the free a-subunit, secondly to develop an IRMA using these antibodies and finally to establish whether measurement of free a-subunit has any clinical advantage. / Thesis (M.Med.Sc.)-University of Natal, Durban, 1990.
124

Uso de sistema de coincidência gama-gama associado à espectroscopia simples em medidas de análise por ativação neutrônica / Use of gamma-gamma coincidence system associated to simple spectroscopy in neutron activation analysis measurements

Ribeiro Junior, Iberê Souza 25 June 2019 (has links)
Nesse trabalho foi desenvolvido um sistema de aquisição γγ que possibilita realizar medidas de Análise por Ativação Neutrônica Instrumental por espectroscopia gama unidimensional e em coincidência simultaneamente para os elementos As, Co, Cs, La, Sc, Se e Sm. Para tal foram realizadas medidas preliminares em sistemas de aquisição γγ baseados em instrumentação analógica e digital a fim de se verificar a eficiência da técnica a partir de medições de padrões sintéticos e análises de materiais de referência certificados. Essas medidas também auxiliaram na escolha do tipo de instrumentação mais apropriada para o desenvolvimento do sistema de aquisição no Laboratório de Física Nuclear Aplicada (LFNA) do IPEN. O sistema montado no LFNA é composto de uma placa digitalizadora da marca CAEN modelo v1724 e dois detectores de germânio hiperpuro. A aquisição dos dados é controlada pelo software MC2Analyzer, que fornece dados brutos de energia e tempo dos pulsos registrados. Foram desenvolvidos dois programas de redução de dados que selecionam os eventos em coincidência a partir dos espectros unidimensionais: o DPP que prepara os dados para serem analisados em programas de análise de espectros bidimensionais; e o AnalisaCaen que trata os dados para sejam analisados em programas de análises de espectros unidimensionais. Foram realizadas análises de materiais de referência certificados biológicos e geológicos, e também padrões sintéticos utilizando-se as técnicas de Análise por Ativação Neutrônica convencional e em coincidência. Os resultados permitiram verificar a confiabilidade dos valores das concentrações dos elementos As, Co, Cs, La, Sc, Se e Sm obtidos com o sistema de coincidência desenvolvido. Os resultados obtidos por ambas as técnicas, Análise por Ativação Neutrônica Convencional e Análise por Ativação Neutrônica em Coincidência, foram comparados e valiados em termos de precisão e exatidão pelo critério de Enscore. Em alguns casos, os resultados de concentração obtidos por meio das medidas de coincidência forneceram melhores do que os resultados obtidos pela espectroscopia gama convencional. / In this study was the developed a γγ acquisition system that make possible to perform Neutron Activation Analysis by single gamma spectroscopy and coincidence γγ spectroscospy simultaneously for the elements As, Co, Cs, La, Sc, Se e Sm. In order to achieve this main goal preliminary measurements in γγ acquisition systems with analogical and digital instrumentation were performed to check the efficiency of technique through measurements of synthetic standard and certified reference material. These measurements also helped to choose the most suitable instrumentation for the development of the acquisition system in the Applied Nuclear Physics Laboratory (LFNA) located at IPEN. The developed system is composed by a CAEN v1724 digitizer board and two hyperpure Germanium detectors. The data acquisition is controled by MC2Analyzer software, which provide raw data of energy and time information of the recorded pulses.Two softwares for data reduction that allow the set the coincident events from single spectra were developed: DPP which prepare the data to be analyzed with softwares for bidimensional espectra.; and AnalisaCaen which handle the data to be analyzed with softwares for single spectra. Determination of the concentration for some elements in certified reference materials and sytnhetic standards were performed applying the conventional and coincidence Neutron Activation Analysis methods. Accuracy and precision of the results obtained by Instrumental Neutron Activation Analysis and Coincidence Instrumental Neutron Activation Analysis were performed by Enscore criteria. The results obtained with this system allowed to check the reliability on the determination for the elements As, Co, Cs, La, Sc, Se and Sm. In some cases the concentration results obtained with coincidence measurements were better than the results from single spectroscopy.
125

"Avaliação da poluição atmosférica por metais na região metropolitana de São Paulo utilizando a Bromélia Tillandsia Usneoides L. como biomonitor" / AVALIAÇÃO DA POLUIÇÃO ATMOSFÉRICA POR METAIS NA REGIÃO METROPOLITANA DE SÃO PAULO, BRASIL, UTILIZANDO A BROMÉLIA TILLANDSIA USNEOIDES L. COMO BIOMONITOR

Nogueira, Cláudio Ailton 14 September 2006 (has links)
Tillandsia usneoides L. é uma bromélia que vive em árvores ou em outros substratos inertes, absorvendo água e nutrientes diretamente do ambiente, sem apresentar raízes. Devido às suas características morfológicas e fisiológicas, esta espécie acumula os poluentes presentes na atmosfera. No presente trabalho, Tillandsia usneoides foi usada como biomonitor de poluição atmosférica por metais em São Paulo, Brasil, que é a maior cidade da América do Sul, com uma população de cerca de 18 milhões de habitantes e uma forte atividade industrial. A área urbana é poluída por emissões industriais mas, de acordo com a Companhia de Tecnologia de Saneamento Ambiental do Estado de São Paulo (CETESB), a agência governamental de controle de qualidade do ar, emissões regulares de cerca de 7,8 milhões de veículos motores são a principal fonte de poluição do ar. As amostras de Tillandsia foram coletadas em um local considerado não poluído e foram expostas por períodos de dois meses em 10 locais da cidade com diferentes níveis de poluição, e em um local de controle. Após a exposição, os metais foram analisados na planta por análise por ativação com nêutrons e por ICP-MS (Pb, Cd, Co, Cu, Ni, Sb e V). Os resultados obtidos mostraram uma concentração notável de Co e Ni nas plantas expostas em uma área industrial, onde existe uma indústria de processamento de metal, que produz cerca de 600 ton/ano de Co e 16.000 ton/ano de Ni. Cobre e crômio se apresentaram igualmente distribuídos em regiões industriais e em locais próximos a avenidas com tráfego intenso, sugerindo que estes elementos podem ser associados tanto a fontes veiculares como industriais. O acúmulo de Cd verificado nas plantas expostas em áreas industriais indica as atividades intrópicas como a principal fonte desse elemento. Não foram identificadas fontes evidentes para o Pb, uma vez que este elemento se apresentou igualmente espalhado por todos os locais de monitoramento. Elementos ligados ao tráfego, como Zn, Ba and Sb apresentaram altas concentrações em plantas expostas em locais situados próximos a avenidas com tráfego pesado (carros, ônibus e caminhões) e podem ser associados a fontes veiculares. Para Zn, os maiores teores foram relacionados a zonas industriais, e este elemento pode ser também associado à presença de fontes de emissão antrópicas. Os elementos terras raras, Fe e Rb, provavelmente têm as partículas de solo como principal fonte. / Tillandsia usneoides L. is an epiphytic bromeliad that lives on trees or other kinds of inert substrates, absorbing water and nutrients directly from the environment without roots. Due to its morphological and physiological characteristics, this species accumulates the pollutants present in the atmosphere. In the present work, Tillandsia usneoides was used as a biomonitor of metal atmospheric pollution in São Paulo, Brazil, which is the biggest city in South America with a population of 18 million inhabitants and a strong industrial activity. The urban area is polluted by industrial emissions but, according to the Environmental Protection Agency of the State of São Paulo (CETESB), the governmental agency of air quality control, regularly occurring emissions from about 7.8 million motor vehicles provide the principal source of air pollution. The Tillandsia samples were collected from an unpolluted area and were exposed bimonthly in 10 sites of the city with different pollution levels and in a control site. After exposure, trace metals were analyzed in the plant by instrumental neutron activation analysis and ICP-MS (Pb, Cd, Co, Cu, Ni, Sb e V). The results of the investigation showed a notable concentration of Co and Ni in the plants exposed in an industrial area where there is a metal processing plant, which produces about 600 tons/year of Co and 16,000 tons/year of Ni. Copper and chromium were equally distributed in industrial regions and in sites near heavy traffic avenues, suggesting that these elements can be associated to both vehicular and industrial sources. A high accumulation of Cd in the plant exposed in industrial areas indicates industrial activities as the main source of this element. For Pb, no evident sources could be identified so far as it was spread evenly along the monitoring sites. Traffic-related elements such as Zn, Ba and Sb presented high concentrations in plants exposed in sites near to heavy traffic avenues (cars, buses and trucks) and may be associated to vehicular sources. For Zn, the highest contents were related to industrial zones and this element can be associated to the presence of anthropogenic emission sources. The rare earth elements, Fe and Rb, probably have soil particles as main source.
126

Valores de referência de elementos em sangue de cavalos da Raça Crioula via metodologia nuclear / Reference values in blood elements in Crioula breed horses by nuclear methodology

Baptista, Tatyana Spinosa 01 October 2010 (has links)
No presente estudo valores de referência para Br (0,0008 - 0,0056 gL-1), Ca (0,089 - 0,369 gL-1), Cl (2,10 - 3,26 gL-1), Fe (0,381 - 0,689 gL-1), I (0,00018 - 0,00266 gL-1), K (1,14 - 2,74 gL-1), Mg (0,030 - 0,074 gL-1), Na (1,36 - 2,80 gL-1), P (<1,99 gL-1), S (0,99 - 2,79 gL-1) e Zn (0,0012 - 0,0048 gL-1) bem como a matriz de correlação em sangue de eqüinos da Raça Crioula foram determinados utilizando metodologia nuclear (técnica de Análise por Ativação com Nêutrons). Estes dados permitiram identificar alterações fisiológicas relacionadas ao gênero e regime de exercício em que se enquadram estes animais (produção de soros hiperimunes no Instituto Butantan, São Paulo, Brasil). Para realização dessas análises foram utilizados 20 cavalos adultos (8 machos e 12 fêmeas) sadios, na faixa etária de 1 a 3 anos e peso médio de 350 kg, mantidos na Fazenda São Joaquim do Instituto Butantan (São Paulo). Outro grupo recém imunizados, composto por 6 cavalos machos (mesmo peso e idade) foram também analisados. Estes dados auxiliaram na interpretação das funções fisiológicas desses elementos no sangue destes animais durante o processo de imunização para produção de soros. / In this study the reference value for Br (0,0008 - 0,0056 gL-1), Ca (0,089 - 0,369 gL-1), Cl (2,10 - 3,26 gL-1), Fe (0,381 - 0,689 gL-1), I (0,00018 - 0,00266 gL-1), K (1,14 - 2,74 gL-1), Mg (0,030 - 0,074 gL-1), Na (1,36 - 2,80 gL-1), P (<1,99 gL-1), S (0,99 - 2,79 gL-1) and Zn (0,0012 - 0,0048 gL-1) as well as the correlation matrix in blood of Crioulo breed horses were determined using nuclear methodology (Neutron Activation Analysis Technique). These data allowed to identifying physiological alterations related to the sex and regime of exercise (hyperimmune sera production at Butantan Institute, São Paulo, Brasil). To perform these analyses was used 20 adult horses (8 males and 12 females), with average mass 350 kg, without clinical signs of disease, 1-3 years old, kept on pasture in São Joaquim Farm at Butantan Institute (São Paulo city). Other group just immunized, composed by 6 equines males (same age and weight), were also analyzed. These data are an important support to understand the physiological functions of these elements in blood during the process of sera production.
127

Avaliação da qualidade dos medicamentos omeprazol e fluoxetina manipulados em algumas farmácias magistrais de Belo Horizonte

Fernanda Peixoto Sepe Melo 01 July 2013 (has links)
Nenhuma / Há uma grande procura da população brasileira por medicamentos manipulados em farmácias de manipulação, que têm papel social incontestável por possibilitar a individualização do medicamento e obtenção de medicamentos não disponíveis industrialmente. Na última década houve rápido crescimento no número de farmácias magistrais no Brasil. A Vigilância Sanitária tem envidado esforços para fiscalização e monitoramento eficaz desses estabelecimentos, realizando publicação e revisão de legislação sanitária, dentre outras ações. Todavia, casos de desvios de qualidade de medicamentos manipulados foram registrados ao longo dos anos e ainda são realidade, com sérias conseqüências à saúde da população e levando a óbito em alguns casos. Ainda, estudos realizados como os de Leal e colaboradores (2006 e 2008) evidenciaram impurezas químicas em matérias-primas e medicamentos manipulados e industrializados. Diante disso, restam dúvidas quanto à qualidade dos medicamentos manipulados ofertados à população e quanto ao rigor das exigências da legislação sanitária vigente e sua adequação ao amadurecimento do setor magistral. O objetivo deste estudo foi avaliar a qualidade de medicamentos manipulados em farmácias magistrais de Belo Horizonte após a publicação da RDC 67/2007, por meio de análises farmacopéicas e de aspecto e rotulagem. Para tanto, foram adquiridos medicamentos de amplo consumo omeprazol e cloridrato de fluoxetina em cinco estabelecimentos de Belo Horizonte, amostrados por amostragem estratificada considerando localização geográfica e número de farmácias por região, seguida por amostragem aleatória. Ainda, foram tratados os resultados das análises do monitoramento da qualidade de manipulados realizado pela Vigilância Sanitária de Minas Gerais em parceria com a Fundação Ezequiel Dias, no ano de 2011. Por fim, foram realizadas análise por ativação neutrônica dos medicamentos manipulados visando detecção e quantificação de impurezas elementares. Os resultados das análises executadas confirmam a preocupação sobre a qualidade dos medicamentos manipulados, uma vez que houve somente 7% de satisfatoriedade nos produtos analisados, e a necessidade de ações rápidas e eficientes do sistema público de saúde para possibilitar a garantia da qualidade dos medicamentos manipulados. / There is a great demand of the population for compounded drugs from pharmacies, which have undeniable social role by allowing the individualization of medication and obtaining drugs not available industrially. In the last decade there has been rapid growth in the number of pharmacies in Brazil. The Sanitary Surveillance is striving for effective monitoring and supervision of these establishments, performing publishing and reviewing health legislation, among other actions. Therefore, there is doubt about the quality of compounded drugs offered to the population and the rigor of the requirements of current health law and its suitability for the maturation of the industry masterful. Still, studies such as Leal and collaborators (2006 and 2008) showed chemical impurities in raw materials and drugs handled and processed. The aim of this study was to evaluate the quality of compounded drugs in pharmacies in Belo Horizonte after publication of RDC 67/2007, through pharmacopoeial analysis, aspect and labeling. Therefore, were purchased drugs from widespread consumption - omeprazole, fluoxetine - in five establishments of Belo Horizonte, sampled by stratified sampling considering geographical location and number of pharmacies per region, followed by random sampling. Also dealt with the results of the analysis of the quality monitoring conducted by Sanitary Surveillance of Minas Gerais in partnership with Fundação Ezequiel Dias, in the year 2011, in compounded medicines. Finally, we performed neutron activation analysis of compounded drugs targeting detection and quantification of elemental impurities.The results of the analysis performed confirms the concern about the quality and safety of compounded medicines, since there was only 7% of satisfactoriness, and the need for fast and efficient actions of public health system to allow quality assurance of compounded drugs.
128

"Avaliação da poluição atmosférica por metais na região metropolitana de São Paulo utilizando a Bromélia Tillandsia Usneoides L. como biomonitor" / AVALIAÇÃO DA POLUIÇÃO ATMOSFÉRICA POR METAIS NA REGIÃO METROPOLITANA DE SÃO PAULO, BRASIL, UTILIZANDO A BROMÉLIA TILLANDSIA USNEOIDES L. COMO BIOMONITOR

Cláudio Ailton Nogueira 14 September 2006 (has links)
Tillandsia usneoides L. é uma bromélia que vive em árvores ou em outros substratos inertes, absorvendo água e nutrientes diretamente do ambiente, sem apresentar raízes. Devido às suas características morfológicas e fisiológicas, esta espécie acumula os poluentes presentes na atmosfera. No presente trabalho, Tillandsia usneoides foi usada como biomonitor de poluição atmosférica por metais em São Paulo, Brasil, que é a maior cidade da América do Sul, com uma população de cerca de 18 milhões de habitantes e uma forte atividade industrial. A área urbana é poluída por emissões industriais mas, de acordo com a Companhia de Tecnologia de Saneamento Ambiental do Estado de São Paulo (CETESB), a agência governamental de controle de qualidade do ar, emissões regulares de cerca de 7,8 milhões de veículos motores são a principal fonte de poluição do ar. As amostras de Tillandsia foram coletadas em um local considerado não poluído e foram expostas por períodos de dois meses em 10 locais da cidade com diferentes níveis de poluição, e em um local de controle. Após a exposição, os metais foram analisados na planta por análise por ativação com nêutrons e por ICP-MS (Pb, Cd, Co, Cu, Ni, Sb e V). Os resultados obtidos mostraram uma concentração notável de Co e Ni nas plantas expostas em uma área industrial, onde existe uma indústria de processamento de metal, que produz cerca de 600 ton/ano de Co e 16.000 ton/ano de Ni. Cobre e crômio se apresentaram igualmente distribuídos em regiões industriais e em locais próximos a avenidas com tráfego intenso, sugerindo que estes elementos podem ser associados tanto a fontes veiculares como industriais. O acúmulo de Cd verificado nas plantas expostas em áreas industriais indica as atividades intrópicas como a principal fonte desse elemento. Não foram identificadas fontes evidentes para o Pb, uma vez que este elemento se apresentou igualmente espalhado por todos os locais de monitoramento. Elementos ligados ao tráfego, como Zn, Ba and Sb apresentaram altas concentrações em plantas expostas em locais situados próximos a avenidas com tráfego pesado (carros, ônibus e caminhões) e podem ser associados a fontes veiculares. Para Zn, os maiores teores foram relacionados a zonas industriais, e este elemento pode ser também associado à presença de fontes de emissão antrópicas. Os elementos terras raras, Fe e Rb, provavelmente têm as partículas de solo como principal fonte. / Tillandsia usneoides L. is an epiphytic bromeliad that lives on trees or other kinds of inert substrates, absorbing water and nutrients directly from the environment without roots. Due to its morphological and physiological characteristics, this species accumulates the pollutants present in the atmosphere. In the present work, Tillandsia usneoides was used as a biomonitor of metal atmospheric pollution in São Paulo, Brazil, which is the biggest city in South America with a population of 18 million inhabitants and a strong industrial activity. The urban area is polluted by industrial emissions but, according to the Environmental Protection Agency of the State of São Paulo (CETESB), the governmental agency of air quality control, regularly occurring emissions from about 7.8 million motor vehicles provide the principal source of air pollution. The Tillandsia samples were collected from an unpolluted area and were exposed bimonthly in 10 sites of the city with different pollution levels and in a control site. After exposure, trace metals were analyzed in the plant by instrumental neutron activation analysis and ICP-MS (Pb, Cd, Co, Cu, Ni, Sb e V). The results of the investigation showed a notable concentration of Co and Ni in the plants exposed in an industrial area where there is a metal processing plant, which produces about 600 tons/year of Co and 16,000 tons/year of Ni. Copper and chromium were equally distributed in industrial regions and in sites near heavy traffic avenues, suggesting that these elements can be associated to both vehicular and industrial sources. A high accumulation of Cd in the plant exposed in industrial areas indicates industrial activities as the main source of this element. For Pb, no evident sources could be identified so far as it was spread evenly along the monitoring sites. Traffic-related elements such as Zn, Ba and Sb presented high concentrations in plants exposed in sites near to heavy traffic avenues (cars, buses and trucks) and may be associated to vehicular sources. For Zn, the highest contents were related to industrial zones and this element can be associated to the presence of anthropogenic emission sources. The rare earth elements, Fe and Rb, probably have soil particles as main source.
129

Implementação do método k0-INAA no laboratório de análise por ativação com nêutrons do IPEN utilizando o programa k0-IAEA. Aplicação à análise de amostras geológicas / k0-NAA implementation and application at IPEN neutron activation laboratory by using the k0-IAEA software. Application to geological sample analysis

Mariano, Davi Brigatto 01 February 2012 (has links)
O Laboratório de Análise por Ativação com Nêutrons (LAN-IPEN) vem analisando amostras geológicas, tais como rochas, solos e sedimentos, há vários anos, empregando o método de análise por ativação com nêutrons comparativa, visando estudos geoquímicos e ambientais. Este trabalho apresenta os resultados obtidos na implementação do método de padronização k0-INAA no LANIPEN, para a análise de amostras geológicas, utilizando o programa k0-IAEA, fornecido pela Agência Internacional de Energia Atômica (IAEA). A razão do fluxo de nêutrons térmico-epitérmico f e o fator &alpha; da distribuição de fluxo de nêutrons epitérmicos do reator IEA-R1 do IPEN foram determinados na estação pneumática de irradiação, e em uma posição de irradiação selecionada, para irradiações curtas e longas, respectivamente. Para obter esses fatores, foi utilizado o chamado método bare triple-monitor com 197Au-96Zr-94Zr. Para avaliar a exatidão e precisão do método, foram analisados os materiais geológicos de referência basalto JB-1 (GSJ) e BE-N (IWG-GIT), andesito AGV-1 (USGS), granito GS-N (ANRT), SOIL-7 (IAEA) e sedimento Buffalo River Sediment (NIST BRS-8704), que representam diferentes matrizes geológicas. Os resultados obtidos para até 30 elementos concordaram com os valores recomendados, com erros relativos (bias) menores que 10%, exceto no caso do Zn no AGV-1 (11,4%) e Mg no GS-N (13,4%). Os critérios estatísticos z-score, zeta-score e U-score foram aplicados para avaliação dos resultados. Pelo critério do z-score, os resultados obtidos puderam ser considerados satisfatórios (z<2), com exceção dos resultados obtidos para Mg no GS-N e no JB-1, e para Yb no Soil-7. O critério estatístico zeta-score se mostrou o mais restritivo, obtendo-se resultados questionáveis (2 < zeta < 3) para Mg no BE-N, Mn no GS-N e Yb no Soil-7, e resultados insatisfatórios (zeta>3) para Mn no BE-N, Mg, Ce e La no GS-N, Mg no JB-1, e Th e Eu no Buffalo River Sediment. Os valores de U-score mostraram que todos os resultados, com exceção do valor para Mg no JB-1, estão dentro de um intervalo de confiança de 95% (se for considerado 1,96 o valor limite para o Uteste para um nível de probabilidade de 95%). Estes resultados indicam excelentes possibilidades para o uso deste método paramétrico no LAN-IPEN para a análise de amostras geológicas em estudos geoquímicos e ambientais. / The Neutron Activation Analysis Laboratory (LAN-IPEN) has been analysing geological samples such as rocks, soils and sediments, for many years with the INAA comparative method, for geochemical and environmental research. This study presents the results obtained in the implementation of the k0-standardization method at LANIPEN, for geological sample analysis, by using the program k0- IAEA, provided by the International Atomic Energy Agency (IAEA). The thermal to epithermal flux ratio f and the shape factor &alpha; of the epithermal flux distribution of the IPEN IEA-R1 nuclear reactor were determined for the pneumatic irradiation facility and one selected irradiation position, for short and long irradiations, respectively. To obtain these factors, the bare triple-monitor method with 197Au- 96Zr-94Zr was used. In order to validate the methodology, the geological reference materials basalts JB-1 (GSJ) and BE-N (IWG-GIT), andesite AGV-1 (USGS), granite GS-N (ANRT), SOIL-7 (IAEA) and sediment Buffalo River Sediment (NISTBRS-8704), which represent different geological matrices, were analysed. The concentration results obtained agreed with assigned values, with bias less than 10% except for Zn in AGV-1 (11.4%) and Mg in GS-N (13.4%). Three different scores were used to evaluate the results: z-score, zeta-score and Uscore. The z-score showed that the results can be considered satisfactory (z<2), except for Mg in GS-N and JB-1, and for Yb in Soil-7. Zeta-score was the most restrictive criterion, indicating questionable results (2 < zeta < 3) for Mg in BE-N, Mn in GS-N and Yb in Soil-7, and unsatisfactory results (zeta>3) for Mn in BE-N, Mg, Ce and La in GS-N, Mg in JB-1, and Th and Eu in Buffalo River Sediment. The U-score test showed that all results, except Mg in JB-1, were within 95% confidence interval. These results indicate excellent possibilities of using this parametric method at the LAN-IPEN for geological samples analysis in geochemical and environmental studies.
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A study of air pollution in Hong Kong: nondestructive multi-element determination of air particulates by means of reactor neutrons and Ge(Li) gamma-ray spectrometer.

January 1978 (has links)
Kwong Lop Sam. / Thesis (M.Phil.)--Chinese University of Hong Kong. / Bibliography: leaves 60-63.

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