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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.
361

Relação entre a diversidade de cupins e as alterações existentes em áreas de caatinga, Sergipe, Brasil / Relation between diversity of termites and alterations existent in areas of Caatinga, Sergipe, Brazil

Viana Junior, Arleu Barbosa 27 July 2013 (has links)
Termites can be considered important indicators for ecological monitoring and analyses, mainly for the Caatinga. This study was aimed to examine how the richness, abundance and composition of termites respond to anthropogenic changes in three areas of Caatinga, remaining in the hinterland of Sergipe. The study was conducted in two districts of the State, Sergipe, where three areas, with different levels of disturbance were selected, namely: Area A1 - pasture; A2 - scrub shrub; A3 - arboreal Caatinga. Each area was separated in twelve transects of 65 x 2 m, and each transect consisted of five plots of 5 x 2 m, where termites were collected in all possible microhabitats. After collection, the termites were properly stored and labeled. After the screening, termites were identified in generic level and, whenever possible, some samples were identified on a specific level. Termites were separated into trophic groups: wood-feeders, humusfeeders, litter-feeders, and soil/wood interface feeders. As environmental variables, soil samples were collected from each plot for subsequent particle size analysis, percent of moisture and soil pH. 180 samples of termites were collected and they were placed in three families, twelve genera and 16 species. The analysis of variance (ANOVA) shows significant differences in richness (F = 10.50, df = 2, p <0.05), and abundance (F = 12.70, df = 2, p <0.05) average per transect among study areas. The species accumulation curve, shows the richness of termites is affected by the degree of disturbance. Wood-feeders were the most abundant group and the area A3 was the only one that presented all trophic groups. The graph of the NMDS ordination shows no clear separation among the composition of termites and the composition of trophic groups, but the similarity analysis shows that areas have significant differences in species composition and trophic groups. All three environmental variables analyzed (moisture, pH and particle size) shows significant differences in some areas. PCA shows clear separation among areas and ANOVA of the first component shows that the areas are statistically different (F = 12.44, df = 2, p <0.001). Given the results presented, it was concluded that termites are good indicators of environmental quality in areas of Caatinga. / Os cupins podem ser considerados importantes indicadores para análises e monitoramento ecológico, principalmente para o bioma Caatinga. Diante disso, o trabalho visou analisar como a riqueza, a abundância e a composição de cupins respondem às alterações antrópicas, em três áreas de Caatinga, existentes no alto sertão sergipano. O estudo foi desenvolvido em dois municípios do Estado de Sergipe, onde três áreas com diferentes níveis de perturbação foram selecionadas, a saber: área A1 pastagem; A2 caatinga arbustiva; A3 caatinga arbórea. Em cada área foram demarcados doze transectos de 65 x 2 m, no qual cada transecto consistia de cinco parcelas de 5 x 2 m, onde os cupins foram coletados em todos os microhabitats possíveis. Após a coleta, os cupins foram armazenados e devidamente etiquetados. Posteriormente à triagem, os cupins foram identificados em nível genérico e, sempre que possível, algumas amostras foram identificada em nível específico. Os cupins foram separados em grupos tróficos: xilófagos, humívoros, ceifadores e intermediários. Como variáveis ambientais, foram coletadas amostras de solo de cada parcela para posterior análises granulométricas e percentual de umidade e pH do solo. Foram coletadas 180 amostras de cupins, distribuídos em três famílias, doze gêneros e 16 espécies. A análise de variância (ANOVA) mostrou haver diferença significativa na riqueza (F = 10.50, gl = 2, p < 0.05) e abundância (F = 12.70, gl = 2, p < 0.05) média por transecto entre as áreas de estudo. A curva de acumulação de espécies, mostrou que a riqueza de cupins é afetada pelo grau de perturbação. Xilófagos foi o grupo mais abundante e a área A3 foi a única a apresentar todos os grupos tróficos. O gráfico de ordenação do NMDS não evidenciou clara separação entre a composição de cupins e a composição dos grupos tróficos, mas a análise de similaridade mostrou que as áreas possuem diferenças significativas em composição de espécies e de grupos tróficos. Todas as três variáveis ambientais analisadas (umidade, pH e granulometria) mostraram diferença significativa em algumas das áreas. A PCA mostra clara separação entre as áreas e a ANOVA do primeiro componente mostrou que as áreas são estatisticamente diferentes (F = 12.44, gl = 2, p < 0.001). Diante dos resultados aqui apresentados, concluiu-se que os cupins são bons indicadores da qualidade ambiental em áreas de Caatinga.
362

Exposição da população adulta da RMSP a contaminantes ambientais: associação entre  o conteúdo corpóreo de metais e fatores de risco / Exposure of MASP adult population to environmental contaminants: association between body burden of metals and risk factors

Simone Harue Kimura Takeda 06 May 2015 (has links)
A exposição humana a contaminantes ambientais é uma preocupação mundial. Nesse contexto, nas últimas décadas, avanços metodológicos têm proporcionado fortes bases quantitativas para a estimativa dos riscos à saúde humana associada a exposições a contaminantes ambientais. A biomonitorização humana é de grande utilidade para estabelecer a distribuição da exposição na população geral, identificar grupos vulneráveis e populações com exposição mais elevada. Os objetivos deste estudo foram avaliar os níveis de exposição da população adulta da região metropolitana de São Paulo (RMSP) aos metais As, Cd, Hg, Pb, Cu e Mn e verificar os possíveis fatores relacionados à exposição. Amostras de sangue e cabelo de doadores de sangue residentes na RMSP há pelo menos um ano foram coletadas em 2009. Os resultados deste estudo indicam que, no geral, a população estudada não está exposta a níveis preocupantes desses metais. As médias geométricas para As, Cd, Pb, Hg, Cu e Mn em sangue foram 3,6 ug/L, 0,12 ug/L, 23,9 ug/L, 1,4 ug/L, 999,4 ug/L e 12,5 ug/L, respectivamente. Em cabelo, as médias geométricas foram 0,02 ug/g, 0,03 ug/g, 0,54 ug/g, 0,13 ug/g, 12,44 ug/g e 0,32 ug/g para As, Cd, Pb, Hg, Cu e Mn, respectivamente. Em sangue, a concentração de As foi associada a nível de educação e o consumo de frango; o nível de Cd foi influenciado pelo hábito de fumar, ramo de atividade e ter residido em área agrícola; a concentração de Pb foi influenciado pelo gênero, idade, nível de educação, uso de medicamentos, consumo de frutos do mar e trabalho pregresso com agrotóxicos; os determinantes de Hg foram consumo de peixe, nível de educação e idade; os níveis de Cu foram influenciados pelo gênero, uso de medicamentos e reforma recente da casa; e a concentração de Mn foi influenciada pela reforma recente da casa, ter residido em área agrícola e trabalho pregresso com agrotóxicos. Em cabelo, os níveis de As foram influenciados pelo gênero, tratamento capilar, frequência de consumo de peixe e raça; o determinante de Cd em cabelo foi o gênero; para o Pb, os determinantes foram gênero e renda familiar; os níveis de Hg foram influenciados pelo gênero, idade, frequência de consumo de peixe, frutos do mar e produtos de origem animal, consumo de bebida alcoólica além de trabalho e raça; os níveis de Cu foram influenciados pelo gênero e o consumo de bebida alcoólica; os fatores associados aos níveis de Mn foram gênero, raça, rua pavimentada e origem da água de beber. Os níveis de Hg, Cd, Cu e Pb em sangue apresentam fraca correlação com os níveis em cabelo / Human exposure to environmental contaminants is a global concern. In this context, in recent decades, methodological advances have provided strong quantitative basis for estimating the risks to human health associated with exposure to environmental contaminants. Human biomonitoring is useful to establish the distribution of exposure in the general population, identify vulnerable groups and populations with higher exposure. The aims of this study were to evaluate the exposure levels of adult population from metropolitan area of São Paulo (MRSP) to metals As, Cd, Hg, Pb, Cu and Mn and verify the related factors to exposure. Blood and hair samples from blood donors living in MASP for at least one year were collected in 2009. The results of this study indicate that, overall, the study population is not exposed to HIGH levels of these metals. Geometric means to As, Cd, Pb, Hg, Cu and Mn in the blood were 3.6 ug/L, 0.12 ug/L, 23.9 ug/L, 1.4 ug/L, 999.4 ug/L and 12.5 ug/L, respectively. Regarding in hair, geometric means were 0.02 ug/g, 0.03 ug/g, 0.54 ug/g, 0.13 ug/g, 12.44 ug/g, 0.32 ug/g for, As, Cd, Pb, Hg, Cu and Mn respectively. In blood, As concentration was affected by education level and poultry consumption; Cd level was affected by smoking status, occupation and lived in rural area in the past; Pb concentration was affected by gender, age, education level, medicine intake, seafood consumption and work with pesticides in the past; Hg determinants were fish consumption, education level and age; Cu levels were affected by gender, medicine intake and refurbished house; and the concentration of Mn was affected by refurbished house, lived in rural area and work with pesticides in the past. Regarding in hair, As levels are affected by gender, hair treatment, frequency of fish consumption and race. The determinant of Cd in hair was gender; for Pb, the determinants were gender and family income; Hg levels were affected by gender, age, frequency of fish consumption, seafood and animal products, alcohol consumption in addition to current work and race; Cu levels were affected by gender and alcohol consumption; related factors to Mn levels were gender, race, paved street and source of drinking water. Hg levels, Cd, Cu and Pb in blood are weakly correlated with levels in hair
363

Resposta espectral do nitossolo submetido a diferentes doses de vinhaça / Spectral response of a Hapludox submitted to different doses of fermentation residue (vinace)

Juliano Araújo Martins 16 January 2012 (has links)
Técnicas de sensoriamento remoto estão se difundindo rapidamente por se tratar de uma fonte rápida de informações, não destrutiva e de baixo custo. O objetivo desse trabalho foi avaliar as alterações químicas e físicas causadas pela aplicação do resíduo da cana-de-açúcar (vinhaça) na resposta espectral de um Nitossolo Vermelho Eutrófico. O experimento foi desenvolvido na Fazenda Areão (22º43S, 47º38O e altitude de 511m) na área experimental do Departamento de Engenharia Biossistemas ESALQ/USP, Piracicaba-SP. O arranjo experimental foi em DIC, com 6 tratamentos e 4 repetições, sendo o tratamento 1 sem irrigação e com adubação convencional junto ao plantio, tratamento 2 fertirrigado com químicos, tratamentos 3, 4, 5 e 6, fertirrigados com 0.5, 1, 2 e 3 vezes a dose recomendada pela CETESB, respectivamente. Foram utilizados tensiômetros para determinação da umidade em cada tratamento nas profundidades 0- 20; 20-40; 40-60 e 60-80 cm. As doses de vinhaça foram parceladas em quatro vezes sendo aplicadas a cada dois meses durante o ciclo da cultura, onde foram realizadas as amostragens de solo, nas profundidades estabelecidas anteriormente, obtendo-se leituras espectrais em laboratório com o sensor hiperespectral Fieldspec Spectroradiometer, das amostras em condições de campo (ACC) e posteriormente de terra fina seca em estufa (TFSE) nos comprimentos de onda que foram de 400 a 2440 nm. Foram realizadas análises químicas e físicas do solo com metodologias já consagradas na literatura. Com base nos dados foram realizadas as discussões para verificação de: 1. Efeitos causados pela aplicação de vinhaça nos atributos químicos do solo; 2. Determinação de propriedades químicas e físicas por meio da resposta espectral do solo; 3. Alterações na resposta espectral causadas pela aplicação da vinhaça em doses parceladas. / Remote sensing techniques are becoming a fast source of in formations, not destructive and at low cost. This work aim to evaluate the chemicals and physicals changes promoted by sugar cane residue application (vinace) on the spectral response of a Hapludox soil. The experiment was developed on Areão farm (22º43 S, 47º38 O e altitude of 511m) on experimental area of the Biosystems Engineering Department of ESALQ/USP, Piracicaba, São Paulo state, Brazil. The experimental arrangement was in completely randomized design, with 6 treatments and 4 repetitions, being the treatment 1 with no irrigation and conventional fertilizer in planting; treatment 2 fertirrigated with chemicals, treatments 3, 4, 5 e 6, fertirrigated with 0.5, 1, 2 e 3 times the recommended doses by CETESB, respectively. To monitor the soil moisture was used tensiometers in depths of 0-20, 20-40, 40-60 e 60-80 cm. The residue doses were divided into four applications applied every two months during the crop cycle, soil samples were collected in the same period and depths previously established. The spectral curves were obtained in laboratory by the Hiperespectral Fieldspec Spectroradiometer sensor, for samples in field conditions (ACC) and air-dried soils (TFSE), for wavelengths ranging from 400 to 2440 nm. Were realized chemicals and physical soil analysis with conventional methodologies and so these data were discussed for verification of: 1. Vinace application effects on soil chemicals and physicals properties; 2. Determination of chemical and physical properties by soil spectral response; 3. Spectral response alterations due application of vinace in split doses.
364

COMPARTIMENTAÇÃO AQUÁTICA DO RESERVATÓRIO RODOLFO COSTA E SILVA-RS, A PARTIR DE VARIÁVEIS LIMNOLÓGICAS E IMAGENS ORBITAIS / AQUATIC COMPARTMENTS IN RODOLFO COSTA E SILVA (RS-BRAZIL) RESERVOIR FROM LIMNOLOGICAL VARIABLES AND ORBITAL IMAGES

Wachholz, Flávio 06 December 2007 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A reservoir presents different environmental traits as a function of the flooded area, water circulation pattern, residence time and nutrients entrance. This situation define the aquatic compartments. The objective was use limnological parameter dynamic and spectral data to identify aquatic compartments in the Rodolfo Costa e Silva reservoir, located on central region of the State of Rio Grande do Sul, on southern region of Brazil. The methodology was based on the measure of water transparence with Secchi disc, Total of Suspended Solids (TSS) and chlorophyll a, b and c. These data were monthly collected in 21 sampling points, distributed over the reservoir during hydrologic year (Oct. 2005 to Sept. 2006). However, chlorophyll samples were collected only two times in autumn season. Satellites images from China-Brazil Earth Resources Satellite 2 (CBERS 2 CCD) and Landsat 5 (TM) were used to make a comparison with limnological and field spectral data. The spatial distribution of limnological parameters was done after data interpolation (weighted average) and its analyses allowed the discrimination of aquatic compartments. During the hydrologic year the transparence changed between 100 and 315 cm and could be divided in two periods: a period with low transparences, from August to November (marked by land tillage for summer crop) and; period with high transparence, from December to June. Based on this variable, the reservoir presented three compartments: a) upstream, with lower transparence; b) downstream, with higher transparence; c) central region, even with high transparence. The TSS ranged from 0.17 to 14.16 mg/L in the hydrologic year. Its behavior was inversely to the water transparence but presented the same three compartments than transparence. The chlorophyll concentration varied from 0.63 to 24.19 μg/L and defined two compartments: upstream and downstream. A larger input of nutrients in upstream let the development of phytoplankton (chlorophylls). Results from CCD and TM images were better when TSS concentration was greater and transparence smaller, associated to the highest data variance. Concentrations of TSS up to 4 mg/L periods with low transparence allowed identify aquatic compartments with blue band (centered on 450 nm) and the red band (centered on 661 nm). The chlorophylls a and c showed absorption bands on the field spectrum of reflectance, making possible establish correlations with limnological parameters (TSS and transparence). Finally, the aquatic compartments that were found out are specially related to the entrance of organic and inorganic matter from terrestrial environment. TSS and chlorophyll decreases into downstream. / Normalmente, um reservatório apresenta diferentes características ambientais em função das áreas alagadas, dos diferentes padrões de circulação, do tempo de residência e entrada de nutrientes, que definem diferentes compartimentos aquáticos. A caracterização limnológica e espectral, com a identificação da dinâmica dos compartimentos aquáticos, foram realizadas no reservatório Rodolfo Costa e Silva RS (Brasil). A metodologia baseou-se na coleta de dados de transparência da água medida pelo disco de Secchi, Totais de Sólidos em Suspensão (TSS) e clorofila a, b e c em 21 pontos amostrais, distribuídos em todo o reservatório e obtidos mensalmente para compor um ano hidrológico (Out. 2005 a Set. 2006); com exceção da clorofila, que foi medida em duas datas durante o outono. Imagens dos satélites CBERS 2 CCD e Landsat 5 TM foram utilizadas para relacionar com os dados limnológicos de campo. A distribuição espacial desses dados limnológicos foi identificada por interpolação por média ponderada, para posterior discriminação dos compartimentos aquáticos. A transparência da água apresentou uma variação no ano hidrológico de 100 a 315 cm e pode ser dividida em dois períodos: das baixas transparências, compreendendo o período de agosto a novembro (período de preparo de solo para a safra agrícola de verão); e de altas transparências, compreendendo o período de dezembro a junho. Essa variável forma três compartimentos: a) o de montante, com menor transparência; b) o de jusante, com maior transparência; c) junto ao dique, de elevada transparência. O TSS apresentou uma amplitude de 0,17 a 14,16 mg/L no ano hidrológico, com comportamento inversamente proporcional ao da transparência definindo compartimentos aquáticos semelhantes. As clorofilas com variação de 0,53 a 24,19 μg/L apresentaram os dois compartimentos aquáticos: o de montante e o de jusante. O maior aporte de nutrientes, à montante do reservatório, proporcionaram o desenvolvimento do fitoplâncton (clorofilas). Os resultados obtidos com imagens CCD e TM foram melhores, quando as concentrações de TSS foram maiores e as transparências foram menores, acompanhados de maior variância. As baixas transparências e as concentrações de TSS maiores que 4 mg/L permitiram identificar compartimentos aquáticos nas bandas azul (450 nm) e vermelha (661 nm). As clorofilas a e c apresentaram bandas de absorção nos espectros de reflectância, permitindo estabelecer correlações. Por fim, os compartimentos aquáticos encontrados estão relacionados, principalmente, ao fornecimento de matéria orgânica e inorgânica oriundas do ambiente terrestre para o sistema aquático, verificado no setor montante, e sua concentração diminui no sentido jusante do reservatório.
365

Change detection in metal oxide gas sensor signals for open sampling systems

Pashami, Sepideh January 2015 (has links)
This thesis addresses the problem of detecting changes in the activity of a distant gas source from the response of an array of metal oxide (MOX) gas sensors deployed in an Open Sampling System (OSS). Changes can occur due to gas source activity such as a sudden alteration in concentration or due to exposure to a different compound. Applications such as gas-leak detection in mines or large-scale pollution monitoring can benefit from reliable change detection algorithms, especially where it is impractical to continuously store or transfer sensor readings, or where reliable calibration is difficult to achieve. Here, it is desirable to detect a change point indicating a significant event, e.g. presence of gas or a sudden change in concentration. The main challenges are turbulent dispersion of gas and the slow response and recovery times of MOX sensors. Due to these challenges, the gas sensor response exhibits fluctuations that interfere with the changes of interest. The contributions of this thesis are centred on developing change detection methods using MOX sensor responses. First, we apply the Generalized Likelihood Ratio algorithm (GLR), a commonly used method that does not make any a priori assumption about change events. Next, we propose TREFEX, a novel change point detection algorithm, which models the response of MOX sensors as a piecewise exponential signal and considers the junctions between consecutive exponentials as change points. We also propose the rTREFEX algorithm as an extension of TREFEX. The core idea behind rTREFEX is an attempt to improve the fitted exponentials of TREFEX by minimizing the number of exponentials even further. GLR, TREFEX and rTREFEX are evaluated for various MOX sensors and gas emission profiles. A sensor selection algorithm is then introduced and the change detection algorithms are evaluated with the selected sensor subsets. A comparison between the three proposed algorithms shows clearly superior performance of rTREFEX both in detection performance and in estimating the change time. Further, rTREFEX is evaluated in real-world experiments where data is gathered by a mobile robot. Finally, a gas dispersion simulation was developed which integrates OpenFOAM flow simulation and a filament-based gas propagation model to simulate gas dispersion for compressible flows with a realistic turbulence model.
366

Impacts of wildlife and cattle grazing on spider (araneae) biodiversity in a highland savanna ecosystem, in Laikipia, Central Kenya

Warui, Charles Mwaura January 2005 (has links)
Spiders were sampled at Mpala Research Centre, Laikipia, Kenya by pitfall-trapping and sweep-netting from May 2001 to July 2002, at a Kenyan Long-term Exclosure Experiment. The aim was to establish species composition, checklist and examine spider responses to disturbances caused by cattle, megaherbivores (giraffe and elephants) and mesoherbivores (other ungulates) by looking at three levels of resolution, namely the overall community, guilds and individual species. This is the first controlled replicated experimental study on the effects on invertebrates (spiders) by different land uses (access by large herbivores). A total of 10,487 individuals from 132 species belonging to 30 families were recorded. The family Salticidae had the highest number of species (24), followed by Gnaphosidae (20), Araneidae and Lycosidae (15 each), Theridiidae and Thomisidae (8 each) and Zodariidae (4). Most of the other families had fewer than 4 species. Throughout the study period, species not previously sampled emerged after rainfall peaks. Exclosure treatments affected plant cover, spider diversity and total species mainly through the effects of cattle, whose presence significantly reduced relative vegetation cover. An increase in vegetation cover significantly increased the diversity, total species and species evenness of the overall spider community (total samples data set). Megaherbivores and mesoherbivores had no effects on overall spider diversity. Relative vegetation cover explained approximately 20-30% of variation in community diversity, species richness and species evenness. At the guild level of resolution, the exclosure treatments had no significant effects on diversity, species richness and species evenness of web builders, plant wanderers and ground wanderers. Plant wanderers were significantly and positively correlated with relative vegetation cover, which explained 17% of variation in their diversity. Six individual species responded strongly and in contrasting ways to the same environmental variables, indicating that this level was more sensitive to environmental changes than guilds or the overall spider community. Spider diversity, relative vegetation cover and rainfall varied at a temporal scale of months and not at a spatial scale of hundreds of metres. Only species diversity and species richness from sweep-netting samples and total species from pitfall-trapping varied significantly at a spatial scale of hundreds of metres. Ordination analysis revealed that sweep-netting samples were a better indicator of grazing impacts than pitfalltrapping or combined samples and grouped to reflect cattle grazing, non-cattle grazing and to a small extent the control treatments. Other ordination analyses showed that only samples from sweep-netting and not from pitfall-trapping, were spatially partitioned at a scale of hundreds of metres. This study concludes that the spider fauna of black cotton soil habitats is rich and useful for environmental monitoring and that monitoring of several individual species as indicator of grazing impacts in savanna could be useful and relatively easy.
367

Evaluation of Crop Seed Powders as Amendments for Purple Nutsedge (Cyperus rotundus) Control Compared to the Traditional Herbicide, Roundup

Betancourt, Eric Taylor 19 June 2015 (has links)
Purple nutsedge (Cyperus rotundus) is a troublesome weed that outcompetes crops and contributes to poor yields. In the past, agriculturalists controlled purple nutsedge by fumigating soil with methyl bromide but the fumigant has since been classified as a controlled substance under the Montreal Protocol. This study evaluated the effectiveness of several alternative purple nutsedge control techniques and compared them with results obtained from the application of Roundup. Concentration treatment effects for the allelopathic seed powders of watercress and turnip were tested in a field trial while seed powders of yellow mustard and sunflower were tested in a potted trial. The allelopathic amendments significantly delayed weed emergence but several factors interfered with long-term effectiveness. Roundup was determined to be the most effective season-long weed control among the treatments consistently leaving the least amount of surviving weeds and underground organs.
368

Novel Colorimetric Sensors with Extended Lifetime for Personal Exposure Monitoring

January 2019 (has links)
abstract: Air pollution has been linked to various health problems but how different air pollutants and exposure levels contribute to those diseases remain largely unknown. Researchers have mainly relied on data from government air monitoring stations to study the health effects of air pollution exposure. The limited information provided by sparse stations has low spatial and temporal resolution, which is not able to represent the actual exposure of individuals. A tool that can accurately monitor personal exposure provides valuable data for epidemiologists to understand the relationship between air pollution and certain diseases. It also allows individuals to be aware of any ambient air quality issues and prevent air pollution exposure. To build such a tool, sensors with features of fast response, small size, long lifetime, high sensitivity, high selectivity, and multi-analyte sensing are of great importance. In order to meet these requirements, three generations of novel colorimetric sensors have been developed. The first generation is mosaic colorimetric sensors based on tiny sensor blocks and by detecting absorbance change after each air sample injection, the target analyte concentration can be measured. The second generation is a gradient-based colorimetric sensor. Lateral transport of analytes across the colorimetric sensor surface creates a color gradient that shifts along the transport direction over time, and the sensor tracks the gradient shift and converts it into analyte concentration in real-time. The third generation is gradient-based colorimetric arrays fabricated by inkjet-printing method that integrates multiple sensors on a miniaturized sensor chip. Unlike traditional colorimetric sensors, such as detection tubes and optoelectronic nose, that are typically for one-time use, the presented three generations of colorimetric sensors aim to continuously monitor multiple air pollutants and the sensor lifetime and fabrication methods have been improved over each generation. Ozone, nitrogen dioxide, formaldehyde and carbon monoxide are chosen as analytes of interest. The performance of sensors has been validated in the lab and field tests, proving the capability of the sensors to be used for personal exposure monitoring. / Dissertation/Thesis / Doctoral Dissertation Chemistry 2019
369

Controle de salvinia molesta em condição de microcosmo por aplicação eletrostática de herbicida e adjuvante e o efeito sobre bioindicadores aquáticos /

Garlich, Nathalia. January 2020 (has links)
Orientador: Marcelo da Costa Ferreira / Resumo: A Salvinia molesta é uma planta aquática de difícil controle e tem causado prejuízos aos ambientes aquáticos. O controle químico com herbicida é uma forma de manejo destas plantas. Contudo, para aplicação de produtos químicos no ambiente aquático é necessário fazer uma avaliação do impacto desta utilização e o potencial risco ambiental. O objetivo deste estudo foi avaliar a eficácia do herbicida imazamox e dos adjuvantes (Dash® e Veget’oil®) em aplicação eletrostática e convencional (CO2 pressurizado) para o controle de S. molesta e os efeitos sobre indicadores ambientais de qualidade de água em condição de microcosmos. Para tanto, foram utilizadas doses de imazamox isolado e acrescido de adjuvantes (600 a 1000 g i.a. ha-1) em aplicação eletrostática e convencional e foram realizadas avaliações de eficácia, clorofila a das plantas, massa fresca e seca e parâmetros químicos, físicos e biológicos de qualidade da água por um período experimental de 60 dias. O imazamox isolado foi mais eficaz no controle de S. molesta na dose de 900 g i.a. ha-1 com 94% em aplicação convencional e 63% em aplicação eletrostática com redução de 95 e 82% de massa fresca e 92 e 62% de massa seca, respectivamente. O imazamox + Dash® foi mais eficaz na dose de 1000 g i.a. ha-1 com 40% de controle em aplicação eletrostática e 25% em aplicação convencional com redução de 50 e 30% da massa fresca e seca, respectivamente. O imazamox com 900 g i.a. ha-1 + 0,5% de Veget’oil® em aplicação sequencial foi mais e... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Salvinia molesta is an aquatic plant difficult to control and cause damage to aquatic environments Chemical control with herbicide is a way of management these plants. However, for the application of chemicals in the aquatic environment it is necessary to make an assessment of the impact of this use and the potential environmental risk. The objective of this study was to evaluate the efficacy of the herbicide imazamox and adjuvants (Dash® and Veget'oil®) in electrostatic and conventional (CO2-pressurized sprayer) application for the control of S. molesta and the effects on environmental indicators of water quality in microcosms. Therefore, doses of imazamox alone and more adjuvants (600 to 1000 g i.a. ha-1) were used in electrostatic and conventional applications and the effectiveness, chlorophyll, fresh and dry biomass and chemical, physical and biological parameters of water quality were evaluated over a period 60 days. Isolated imazamox was more effective in controlling S. molesta at a dose of 900 g i.a. ha-1 with 94% in conventional application and 63% in electrostatic application, with a reduction of 95 and 82% in fresh weight and 92 and 62% dry weight, respectively. Imazamox + Dash® was more effective at a dose of 1000 g i.a. ha-1 with 40% control in electrostatic application and 25% in conventional application with a reduction of 50 and 30% in fresh and dry weight, respectively. The imazamox with 900 g i.a. ha-1 + 0,5% Veget'oil® in sequential application was more effe... (Complete abstract click electronic access below) / Doutor
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Assessing Public Health Burden Associated with Exposure to Fine Particulate Matter and Its Chemical Components in the United States

Li, Ying 01 May 2015 (has links)
No description available.

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