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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.
551

Vliv emisí prachových částic a pachových látek z intenzivního výkrmu drůbeže na životní prostředí v okolí chovu.

COUFAL, Marek January 2018 (has links)
This thesis is about evaluation of the influence of odorus substances and dust particles from intensive poultry farming to the environment. Measurement was done on a family farm near the forest in spring and autumn in 2017. The fattening of broilers is carried out there in four fattening halls with a total of 103,000 units. Poultry is fattened on the farm for 238 days during the whole calendar year after 7 batches. Sampling was carried out from one of these halls. The values obtained are ranged from 59 / m3 to 215 / m3 for odorous substances and particulate matter PM10 ranging from 0.061 mg to 0.0765 mg. PM2.5 dust particles showed values of 0.042 mg after 0.1535 mg. Evaluation of odorous substances was performed by the method of dynamic olfactometry according to the standard ČSN EN 13 725. The values obtained were ranged from 59 / m3 to 215 / m3. The range of production specific emissions was between 0.013828 and 0.298366 ( / / s). The PM10 particle emission production rate between 0,0000179 and 0,0001094 (mg / pc / year) and PM2,5 from 0,0000642 to 0,0001672 (mg / pc / year) was determined using the particulate measurement methodology. These data were compared with the relevant air pollution limits according to Annex No. 1 to the Act on Air Protection No.201 / 2012 Coll., Immission background in the locality and a dispersion study was prepared for them.
552

Mutagenicidade de solos como estratégia na avaliação de riscos de área contaminada

Pohren, Roberta de Souza January 2011 (has links)
O solo é um dos compartimentos mais atingidos pelo acúmulo de poluentes de origem antrópica, pois atua como depósito de poluentes e como fonte para outros ambientes de interface. Este estudo investigou sítio contaminado com resíduos da indústria de preservativos de madeira como fonte de compostos mutagênicos; definiu rotas e abrangência na dispersão desses contaminantes pela remobilização de partículas e deposição atmosférica, associando riscos ambientais e à saúde. Foram selecionados locais de amostragem para solos e poeira domiciliar a distâncias gradativas a partir de SI (pool de solo da área industrial), SR150 (150m), SR500 e SR1700; para poeira foi coletado um pool em área de risco, DR385 (385m) e em DR1700. Foi avaliada a atividade mutagênica através do ensaio Salmonella/microssoma, método de microssuspensão, em linhagens que detectam erro no quadro de leitura (TA98 e TA97a), substituição de pares de bases do DNA (TA100), em presença e ausência de metabolização hepática de ratos (S9mix) e YGs 1041, 1042 e 1024 para a definição de nitroderivados. Foram preparados extratos ácidos, visando definir os efeitos de compostos inorgânicos como metais pesados e de extratos orgânicos para avaliar principalmente hidrocarbonetos policíclicos aromáticos (HPAs) e nitroderivados. Os extratos foram testados também quanto à concentração dos 16 HPAs considerados poluentes prioritários pela USEPA, quanto a metais pesados de interesse e quanto ao contaminante pentaclorofenol (PCP) como marcador específico da atividade do sítio industrial. Através das análises de metais pesados foi detectado um gradiente de respostas, onde tanto a concentração de metais totais quanto a fração biodisponível de Cr e Cu apresentaram valores mais altos para SI em relação aos solos de entorno; para As, apenas na avaliação da concentração total do elemento, SI foi superior. Em relação aos efeitos mutagênicos decorrentes da mistura de compostos inorgânicos as respostas não permitiram uma gradação entre as diferentes distâncias. O solo fonte SI mostrou mutagênese nas diferentes linhagens, em especial em TA97a na ausência de S9mix. As amostras de entorno apresentaram potência mutagênica em pelo menos duas cepas, mas apenas uma consonante com SI. O solo SR500, mostrou mutagênese diferenciada e resposta expressiva na linhagem TA98 com S9 mix. No entanto, o local SR1700 mostrou ausência de influência a partir da área contaminada caracterizando uma área de referência. Nos extratos orgânicos, as respostas de mutagênese mostram um padrão de contaminação nas áreas de influência semelhante ao apresentado por SI, parecendo indicar a mobilidade de compostos orgânicos a partir da fonte para as áreas de entorno. Houve um predomínio de compostos de ação indireta, sendo os valores de SI entre 107 a 1455 rev/g de solo. Nos locais de entorno, observou-se padrão similar em SR150; já em SR500 valores elevados de mutagênese de ação direta foram evidenciados em TA97a; SR1700, embora apresentando mutagênese do tipo erro no quadro de leitura em presença de S9 mix, mostrou um decréscimo de efeitos. Os testes com as linhagens YG indicaram que compostos nitrados têm ação significativa na mutagênese direta encontrada, com exceção de SR500. Foi detectada ainda a presença de hidroxiamino-compostos em todas as amostras de solos através da linhagem YG1024. Na investigação da poeira residencial de entorno foram observadas respostas mutagênicas nas diferentes cepas testadas em DR385, mono e dinitroarenos do tipo substituição de pares de bases (YG1042) e hidroxiamino-compostos (YG1024); em DR1700 não foi observada resposta positiva. Concentrações de HPAs potencialmente carcinogênicos se estendem no solo da área interna até o do local de referencia, bem como na poeira domiciliar da área de risco indicando gradiente de concentrações e efeitos. A concentração de PCP no pool de poeira (DR385) foi (0,491 mg/Kg), similiar a observada em SI, (0,431 mg/Kg), definindo uma rota efetiva de dispersão a partir da área industrial para regiões do entorno. Ficou evidenciada a possibilidade de dispersão de mutágenos da área contaminada para regiões de entorno, sendo possível detectar gradientes de distância, favorecendo estimativas de risco. O estudo mostrou que é fundamental avaliar a extensão da contaminação a partir de fontes de solo impactado, visando delimitar qualquer medida de remediação dos ambientes atingidos e evitar danos potenciais ao equilíbrio ecológico e à saúde humana. / Soil is one of the compartments most affected by the accumulation of anthropic pollutants, since it acts as a deposit for pollutants and as a source for other interface environments. This study investigated a site contaminated with residues of the wood preservative industry as a source of mutagenic compounds; it defined the routes and area covered by dispersion of these contaminants through the remobilization of particles and atmospheric deposition, associating environmental and human health risks. Sampling sites were selected for soils and dusts at gradually increasing distances from SI (pool of soil from the industrial area), SR150 (150m), SR500 and SR1700; a pool was of residential dust was collected in the area of risk, DR385 (385m) and at DR1700. Mutagenic activity was evaluated by the Salmonella/microsome assay, microsuspension method, in strains that detect frameshift error (TA98 and TA97a), DNA base pair substitution (TA100), in the presence and absence of hepatic metabolization of rats (S9 mix) and YGs 1041, 1042 and 1024 to sough nitroderivates. Acid extracts were prepared to define the effects of inorganic compounds such as heavy metals, and organic extracts in evaluating mainly polycyclic aromatic hydrocarbons (PAHs) and nitroderivates. The extracts were tested also for the concentration of the 16 PAHs considered priority pollutants by USEPA, for heavy metals of interest and for contaminant pentachlorophenol (PCP) as a specific marker of the industrial site activity. A gradient of responses was detected through analyses of heavy metals , where both the concentration of heavy metals and the bioavailable fraction of Cr and Cu presented higher values for SI compared to the surrounding soils; for As, SI was superior only to evaluate the total concentration of the element. As to the mutagenic effects of the mixture of inorganic compounds, the responses did not allow a grading between the different distances. The source soil SI presented mutagenesis in the different strains, especially in TA97a in the absence of S9mix. The samples from the surrounding area presented mutagenic potency in at least two strains, but only one in accordance with SI. Soil SR500 showed differentiated mutagenesis and an expressive response in the TA98 strain with S9 mix. However, site SR1700 showed no influence from the contaminated area, characterizing an area of reference. In the organic extracts, the mutagenesis responses showed a pattern of contamination of the areas of influence similar to that presented by SI, and appear to indicate the mobility of organic compounds from the source to the surrounding areas. Indirect action compounds predominated, and the values of SI were from 107 to 1455 rev/g soil. At the surrounding sites, a similar pattern was observed in SR150; on the other hand, in SR500 high values of direct action mutagenesis were evidenced in TA97a; SR1700, although presenting mutagenesis in frameshift strains in the presence of S9 mix, showed diminished effects. Tests with YGs strains indicate that the nitrated compounds exert a significant action on the direct mutagenesis found, except for SR500. Further, hydroxyamine-compounds were detected in all soils samples through strain YG1024. Investigating residential dust from the surrounding area, mutagenic responses were observed in the different strains tested in DR385, mono and dinitroarenes of the pair substitution mutation type (YG1042) and hydroxyamine-compounds (YG1024); no positive response was observed in DR1700. Potentially carcinogenic PAHs concentrations are on the soil from the internal area until the site of reference, and also in the residential dust of the risk area, indicating a gradient of concentrations and effects. PCP concentration in the dust pool (DR385) was (0.491 mg/Kg), similar to that observed in SI, (0.431 mg/Kg), defining an effective dispersion route from the industrial area to the surrounding regions. The possibility of mutagen dispersion from the contaminated area to the surrounding regions was shown, and gradients of distance favoring risk estimates were detected. The study showed that it is essential to evaluate the extent of contamination from the sources of soil that have been impacted, with a view to delimiting any remedial measure for the environments affected and avoiding potential damage to the ecological balance and human health.
553

Soiling of Photovoltaic Modules: Modelling and Validation of Location-Specific Cleaning Frequency Optimization

January 2014 (has links)
abstract: To increase the deployment of photovoltaic (PV) systems, a higher level of performance for PV modules should be sought. Soiling, or dust accumulation on the PV modules, is one of the conditions that negatively affect the performance of the PV modules by reducing the light incident onto the surface of the PV module. This thesis presents two studies that focus on investigating the soiling effect on the performance of the PV modules installed in Metro Phoenix area. The first study was conducted to investigate the optimum cleaning frequency for cleaning PV modules installed in Mesa, AZ. By monitoring the soiling loss of PV modules mounted on a mock rooftop at ASU-PRL, a detailed soiling modeling was obtained. Same setup was also used for other soiling-related investigations like studying the effect of soiling density on angle of incidence (AOI) dependence, the climatological relevance (CR) to soiling, and spatial variation of the soiling loss. During the first dry season (May to June), the daily soiling rate was found as -0.061% for 20o tilted modules. Based on the obtained soiling rate, cleaning PV modules, when the soiling is just due to dust on 20o tilted residential arrays, was found economically not justifiable. The second study focuses on evaluating the soiling loss in different locations of Metro Phoenix area of Arizona. The main goal behind the second study was to validate the daily soiling rate obtained from the mock rooftop setup in the first part of this thesis. By collaborating with local solar panel cleaning companies, soiling data for six residential systems in 5 different cities in and around Phoenix was collected, processed, and analyzed. The range of daily soiling rate in the Phoenix area was found as -0.057% to -0.085% for 13-28o tilted arrays. The soiling rate found in the first part of the thesis (-0.061%) for 20o tilted array, was validated since it falls within the range obtained from the second part of the thesis. / Dissertation/Thesis / Masters Thesis Engineering 2014
554

Avaliacao da contaminacao por elementos inorganicos e esteres ftalicos em poeira domestica da regiao metropolitana de Sao Paulo / Assessment of contamination for inorganic elements and phthalate esters in household dust from the metropolitan region of São Paulo

SCAPIN, VALDIRENE de O. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:27:18Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:59:13Z (GMT). No. of bitstreams: 0 / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
555

Avaliação qualitativa de métodos de tratamento de sementes de soja / Qualitative evaluation of soybean seed treatment methods

Del Bem Junior, Luciano 06 December 2017 (has links)
Submitted by LUCIANO DEL BEM JUNIOR null (lucianojunior20@hotmail.com) on 2018-01-31T17:14:28Z No. of bitstreams: 1 Dissertação final - Luciano Del Bem Junior.pdf: 1638408 bytes, checksum: 0216b8bf0c83a04706ef77739317bb8a (MD5) / Approved for entry into archive by Maria Lucia Martins Frederico null (mlucia@fca.unesp.br) on 2018-01-31T17:29:51Z (GMT) No. of bitstreams: 1 Del Bem Junior_l_me_bot.pdf: 1638408 bytes, checksum: 0216b8bf0c83a04706ef77739317bb8a (MD5) / Made available in DSpace on 2018-01-31T17:29:51Z (GMT). No. of bitstreams: 1 Del Bem Junior_l_me_bot.pdf: 1638408 bytes, checksum: 0216b8bf0c83a04706ef77739317bb8a (MD5) Previous issue date: 2017-12-06 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O tratamento de sementes se caracteriza por ser um processo capaz de erradicar e/ou prevenir patógenos e pragas que podem causar prejuízos às sementes. O método de tratamento de sementes pode influenciar no desprendimento de poeira, desempenho na plantabilidade, além de ocasionar diminuição da dose por semente quando realizado de maneira não uniforme. Portanto, este trabalho teve como objetivo avaliar o efeito do tratamento fitossanitário de sementes de soja pelos métodos on farm e industrial (TIS) sobre abrasão, geração de poeira, fluidez e plantabilidade, a fim de obter melhor qualidade do produto final e a otimização deste processo. Para as avaliações, o estudo contou com cinco tratamentos: on farm – fungicida + inseticida + água; TIS - fungicida + inseticida + polímero; TIS - fungicida + inseticida + polímero + pó secante; TIS - fungicida + inseticida + polímero + pó secante + fertilizante mineral; testemunha (sem tratamento). O delineamento experimental foi inteiramente casualizado para todos os testes. Para o tratamento on farm utilizou-se betoneira com acionamento elétrico, tratando 10 kg de sementes. No TIS foi utilizada máquina de tratamento de sementes por batelada, equipada com disco de atomização rotativo. A poeira foi determinada pelo teste dust-off e os tratamentos distribuídos no esquema fatorial 5 x 4, cinco tratamentos de sementes e quatro intervalos de tempo (2; 32; 62 e 92 dias após tratamento), com quatro repetições. O teste de abrasão foi conduzido em friabilômetro, seguindo o mesmo delineamento no esquema fatorial 5 x 3, cinco tratamentos de sementes e três posições de inserção do papel-filtro, com quatro repetições. Após este procedimento efetuou-se a análise de desprendimento do tratamento das sementes por cromatografia líquida de alta eficiência (HPLC), no esquema fatorial 4 x 2, quatro tratamentos e duas condições de abrasão (antes e após o teste). Já na avaliação da fluidez das sementes utilizou-se funil Niklas®, onde foi conduzido o teste no esquema fatorial 5 x 4, com cinco tratamentos e quatro intervalos de tempo (0; 7; 14 e 21 min. após o tratamento), com seis repetições, a fim de quantificar o tempo de secagem de cada tratamento. A plantabilidade das sementes foi determinada em simulador do sistema pneumático, por meio da contagem de falhas, sementes duplas e múltiplas, no esquema fatorial 5 x 4, cinco tratamentos e quatro velocidades, em quatro repetições. Pelos testes dust-off e abrasão, as sementes tratadas com polímero, sem adição do fertilizante mineral, obtiveram os menores valores de resíduo tóxico. As análises em HPLC evidenciaram que nos tratamentos com polímero houve menor perda do inseticida. Pelo teste de fluidez o tratamento com pó secante, sem fertilizante mineral, apresentou menor tempo de secagem das sementes e, portanto, maior fluidez. As sementes cobertas com pó secante reduziram os valores de falhas e sementes duplas até a velocidade de 6 km h-1. / The seed treatment is characterized by being a process capable of eradicating and / or preventing pathogens and pests that can damage the seeds. Seed treatment method can influence the release of dust, performance in planting, and cause seed dose reduction when performed in an uneven manner. The objective of this study was to evaluate the effect of soybean seeds phytosanitary treatment by on farm and industrial methods (IST) on abrasion, dust generation, flowability and plantability, in order to obtain better final product quality and optimization of this product process. For the evaluations, the study had five treatments: on farm - fungicide + insecticide + water; IST - fungicide + insecticide + polymer; IST - fungicide + insecticide + polymer + drying powder; IST - fungicide + insecticide + polymer + drying powder + mineral fertilizer; control (without treatment). The experimental design was completely randomized for all tests. For the on farm treatment, an electric mixer was used, treating 10 kg of seeds. In the IST was used a batch seed treater, equipped with rotary atomizing disk. The dust was determined by the dust-off test and the treatments were distributed in the 5 x 4 factorial scheme, five seed treatments and four time intervals (2, 32, 62 and 92 days after treatment), with four replications. The abrasion test was conducted in a friabilometer, following the same design in the 5 x 3 factorial scheme, five seed treatments and three insertion positions of the filter paper, with four replications. After this procedure the seed treatment was analyzed by high performance liquid chromatography (HPLC), in the 4 x 2 factorial scheme, four treatments and two abrasion conditions (before and after the test). The Niklas® funnel was used to evaluate the fluidity of the seeds, conducting in a 5 x 4 factorial scheme, with five treatments and four-time intervals (0, 7, 14 and 21 min after treatment), with six replicates, in order to quantify the drying time of each treatment. Seed plantability was determined in a pneumatic system simulator, by counting faults, double and multiple seeds, in a factorial scheme 5 x 4, with five treatments and four speeds, in four replications. By the dust-off and abrasion tests, the seeds treated with polymer, without addition of the mineral fertilizer, obtained the lowest amounts of toxic residue. The HPLC analysis showed that in the polymer treatments there was less insecticide loss. In the fluidity test, the treatment with drying powder and without mineral fertilizer presented a lower drying time of the seeds and, therefore, a higher fluidity. The seeds covered with drying powder reduced the number of fault and double seeds up to the speed of 6 km h-1.
556

A impermanência do processo: poeira, caminhos, objetos / The process impermanence: dust, ways, objects

Cristiana Nogueira Menezes Gomes 27 March 2009 (has links)
Essa dissertação levanta um conjunto de questões relacionadas à reflexão do processo artístico. Focando em conceitos como poeira, melancolia, flânerie e memória, foi desenvolvido um diálogo entre Walter Benjamin, W.G. Sebald, Georges Perec, Susan Sontag, Georges Bataille e Giorgio Agamben e, também, foram pesquisados os trabalhos de Marcel Duchamp, Joseph Cornell e Robert Smithson. O texto é dividido em três momentos nos quais as principais questões são expandidas em fragmentos que consistem em proposições inseridas na arte contemporânea. Junto com o texto é apresentada uma série de imagens que pertencem ao conjunto de fotos que serão expostas durante a defesa / This dissertation raises a set of questions related to the reflection of the artistic process. Focusing on concepts like dust, melancholy, flânerie and memory, it was developed a dialogue among Walter Benjamin, W.G. Sebald, Georges Perec, Susan Sontag, Georges Bataille and Giorgio Agamben and also, the works from Marcel Duchamp, Joseph Cornell and Robert Smithson were researched. The text is divided in three moments, which the principal questions are expanded in fragments that consist in propositions inserted in the contemporary art. Along with the text is showed a series of images that belong to a set of photos that will be exposed during the presentation
557

Desenvolvimento de um processo para redução do teor de cloro no pó de aciaria elétrica

Buzin, Pedro Jorge Walburga Keglevich de January 2016 (has links)
Na fabricação de aço pelo processo de aciaria elétrica há geração de vários tipos de resíduos, dentre estes, as poeiras de aciaria. Este resíduo possui como principais constituintes os elementos Fe, O e Zn, sendo considerado perigoso na maioria dos países. Além destes elementos, a presença do cloro provoca interferência deletéria na maioria dos processos de reciclagem ou incorporação do PAE em outros materiais. Por este motivo, o cloro representa um obstáculo à ampliação das possibilidades de destinação ou reciclagem destas poeiras. Este trabalho propõe uma nova tecnologia hidrometalúrgica para a redução do teor de cloro solúvel das poeiras para teores menores que 0,3% (b.s). Esta técnica..., de modo a possibilitar a aplicação de um processo especialmente desenvolvido de lixiviação aquosa, que evita a necessidade de agitação e equipamentos especiais. O principal objetivo foi reduzir o teor de cloretos das poeiras utilizando uma baixa relação sólido:líquido, em um processo de maior sustentabilidade e menor utilização de energia e recursos hídricos. Nos ensaios foram utilizadas poeiras previamente caracterizadas em seus principais elementos e provenientes de três usinas semi-integradas, cada uma com um perfil produtivo diferente e com teores de cloro médio variando de 2,01 a 5,26% (b.s). Foram testadas duas variantes principais desta nova tecnologia, em temperatura ambiente e a 60°C. Os resultados alcançados demonstraram a possibilidade de redução do teor de cloro solúvel das poeiras acima de 90%, com uma relação sólido:líquido de até 1:0,43. Também foi possível a geração de soluções concentradas de sais que atingiram até 20% em massa de concentração, em temperatura ambiente, sem necessidade de evaporação. A fácil obtenção destas soluções concentradas potencializa a aplicação e o desenvolvimento futuro de novas tecnologias para recuperação dos sais de poeiras de aciaria elétrica, principalmente sais de potássio. O material residual, com teor de cloro reduzido, possui melhor qualidade e aptidão para ser utilizado como matéria-prima em novos ou tradicionais processos de reciclagem e incorporação em outros materiais. / The Electric steelmaking generates several types of wastes, among them the electric arc furnace dust – EAFD. This residue has as main constituents the elements Fe, O and Zn, being considered dangerous in most countries. In addition to these elements, the presence of chlorine causes deleterious interference in most of recycling processes or incorporation in other materials. For this reason, chlorine represents an obstacle to increase the possibilities for disposal or recycling these dusts. This work proposes a new hydrometallurgical technology to reduce the soluble chlorine content of these dusts to lower levels than 0.3 wt% (dry basis). This technique is based on … to enable the application of a specially designed aqueous leaching process, that avoids the need for special equipment and stirring. The main objective is to reduce the chloride content of dusts using a low solid:liquid ratio in a process of greater sustainability and lower use of energy and water resources. In the tests, dusts previously characterized in main elements were used. These dusts come from three semi-integrated plants, each one with a different production profile and average chlorine content ranging from 2.01 to 5.26 wt% (dry basis). Two main variants of this new technology were tested at room temperature and 60°C. The results showed the possibility of reducing soluble chlorine content of dusts at levels above 90%, with solid:liquid ratio up to 1: 0,43. It was also possible to generate concentrated salt solutions, reaching up to 20 wt% concentration of salts, at room temperature, without evaporation. These concentrate solutions are easily obtained and potentialize the application and future development of new technologies for recovery of electric arc furnace dust salts, especially potassium salts. The residual material with low chlorine content, has better quality and suitability for use as raw material in new or traditional recycling processes and incorporation in other materials.
558

Modelo termodinâmico para o forno Waelz

Reis, Bruno Henrique January 2015 (has links)
O pó de aciaria elétrica é um importante subproduto da indústria siderúrgica devido ao seu alto teor de zinco. Assim, tecnologias vêm sendo desenvolvidas visando seu aproveitamento, sendo o forno Waelz a mais difundida delas atualmente. No entanto, sua operação, por contar com um forno rotativo de grandes dimensões que abriga uma infinidade de fenômenos físico-químicos, apresenta difícil previsibilidade ab initio. Por essa razão, este trabalho faz uso de uma ferramenta avançada da termodinâmica computacional, destinada à modelagem de processos, chamada SimuSage, a fim de modelar o seu comportamento. Para a criação do modelo utilizou-se também uma base de dados termodinâmicos advinda do software FactSage e a plataforma de desenvolvimento Lazarus. Com base em dados e resultados operacionais da literatura, foi possível realizar simulações nos modos adiabático e isotérmico, comparando os resultados com os da prática industrial. Constatou-se uma grande capacidade do modelo de reproduzir os resultados da literatura, mesmo quando não há muita informação para aferição dos parâmetros, gerando boa concordância com a composição química relatada dos produtos Óxido Waelz e Escória Waelz. / The electric arc furnace dust is an important by-product of the steel industry due to its high content of zinc. Thus, technologies have been developed aiming for its use, and the Waelz Kiln is the most widespread of them today. However, counting on a very large rotary kiln that houses an infinity of physico-chemical phenomena, its operation is difficult to predict ab initio. For this reason, in order to model its behaviour this work uses an advanced tool of computational thermodynamics designed to process modelling, called SimuSage. To create the model, a thermodynamic database, provided by the FactSage software, as well as a development platform, Lazarus IDE, were also used. Based on operational data and results from de literature, it was possible to perform simulations on both adiabatic and isothermal modes comparing its results with the industrial practice. A great capability of the model to reproduce results from the literature was found, even when there is not much information for the parameters calibration, generating good agreement regarding the reported chemical composition for the products, Waelz Oxide and Waelz Slag.
559

Environmental Monitoring Strategies for Assessing Chemical Threats to Public Health

January 2018 (has links)
abstract: Monitoring human exposure to chemicals posing public health threats is critically important for risk management and for informing regulatory actions. Chemical threats result from both environmental pollutants and elected substance use (e.g., consumption of drugs, alcohol and tobacco). Measuring chemical occurrence and concentrations in environmental matrices can help to pinpoint human exposure routes. For instance, indoor dust, a sink of indoor environmental contaminants, can serve to assess indoor air contamination and associated human exposures. Urban wastewater arriving at treatment plants contains urine and stool from the general population, the analysis of which can provide information on chemical threats in the community and ongoing harmful exposures. Analysis of sewage sludge can serve to reveal the identity and quantity of persistent organic pollutants in cities and inform estimates of toxic body burdens in local populations. The objective of this dissertation was to investigate the occurrence and quantity of select, potentially harmful, anthropogenic chemicals in various environmental matrices and to explore the diagnostic value of analytical assays for informing public health decision-making. This dissertation (i) is the first to report spatio-temporal variations and estrogenic burdens of five parabens in sewage sludge from at the U.S. nationwide scale; (ii) represents the first China-wide survey to assess the occurrence and toxic emissions of parabens, triclosan, triclocarban, as well as triclocarban metabolites and transformation products contained in Chinese sewage sludge; (iii) documents the first use of a dispersive solid phase extraction method for indoor dust to measure dust-borne parabens, triclosan and triclocarban and estimating associated human exposures from dust ingestion; and (iv) is the first U.S. study to assess population-level alcohol and nicotine consumption in three U.S. communities using wastewater-based epidemiology (WBE). Obtained data on baseline levels of selected emerging contaminants in sewage sludge and indoor dust can serve to inform the future monitoring needs, risk assessment, and policy making. This work showcases the utility of WBE and urban metabolism metrology via dust and sewage sludge analysis to assess human behavior (e.g., drinking and smoking) and exposure risks more rapidly, efficiently and anonymously than traditional approaches can. / Dissertation/Thesis / Doctoral Dissertation Biological Design 2018
560

Eolian Deposition and Soil Fertility in a Prehistoric Agricultural Complex in Central Arizona

January 2012 (has links)
abstract: Prehistoric farmers in the semi-arid American Southwest were challenged by marked spatial and temporal variation in, and overall low levels of, precipitation with which to grow their crops. One strategy they employed was to modify their landscape with rock alignments in order to concentrate surface water flow on their fields. A second challenge that has been less focused on by archaeologists is the need to maintain soil fertility by replenishing nutrients removed from the soil by agricultural crops. Numerous studies have shown that rock alignments can result in long-lasting impacts on soil properties and fertility. However, the direction and magnitude of change is highly variable. While previous work has emphasized the importance of overland flow in replenishing soil nutrient pools, none have investigated the influence of eolian deposition as a contributor of mineral-derived nutrients. This thesis explores the effects of the construction of rock alignments, agricultural harvest, and eolian deposition on soil properties and fertility on Perry Mesa within the Agua Fria National Monument. This site experienced dramatic population increase in the late 1200s and marked depopulation in the early 1400s. Since that time, although agriculture ceased, the rock alignments have remains, continuing to influence runoff and sediment deposition. In the summer of 2009, I investigated deep soil properties and mineral-derived nutrients on fields near Pueblo La Plata, one of the largest pueblos on Perry Mesa. To examine the effects of rock alignments and agricultural harvest independent of one another, I sampled soils from replicated plots behind alignments paired with nearby plots that are not bordered by an alignment in both areas of high and low prehistoric agricultural intensity. I investigated soil provenance and the influence of deposition on mineral-derived nutrients through analysis of the chemical composition of the soil, bedrock and dust. Agricultural rock alignments were significantly associated with differences in soil texture, but neither rock alignments nor agricultural history were associated with significant differences in mineral-derived nutrients. Instead, eolian deposition may explain why nutrient pools are similar across agricultural history and rock alignment presence. Eolian deposition homogenized the surface soil, reducing the spatial heterogeneity of soils. Dust is important both as a parent material to the soils on Perry Mesa, and also a source of mineral-derived nutrients. This investigation suggests that prehistoric agriculture on Perry Mesa was not likely limited by long term soil fertility, but instead could have been sustained by eolian inputs. / Dissertation/Thesis / M.S. Biology 2012

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