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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.
111

Capacidade máxima de acúmulo de carbono em solos cultivados com cana-de-açúcar / Maximum capacity of carbon accumulation in soils cultivated with sugarcane

Brandani, Carolina Braga 27 August 2013 (has links)
Um dos principais entraves na cultura da cana-de-açúcar quanto à sustentabilidade do solo é o manejo da cultura e da colheita. O objetivo deste estudo foi avaliar os estoques de C e sua dinâmica em diferentes frações da MOS (matéria orgânica do solo) em áreas cultivadas com cana-de-açúcar sob os manejos com e sem queima e, sob adubação orgânica com diferentes períodos de adoção (4 e 12 anos), tendo uma área de vegetação nativa (Cerradão) como referência. As áreas localizam-se em Goianésia-GO, sendo todas representativas da classe dos Latossolos Vermelho-Amarelo distróficos. Foram avaliados os teores de C e N do solo e seus respectivos estoques, além dos teores de C e N e, das abundâncias isotópicas do 13C e 15N para as frações organominerais < 53 ?m, 75-53 ?m e 2000- 75 ?m (fração orgânica e organomineral) da MOS. De posse desses resultados, objetivou-se simular a capacidade máxima de acúmulo de C, a partir do modelo Century, enfatizando os manejos avaliados e texturas de solos contrastantes. Os teores de C foram maiores para o manejo orgânico-4, em relação às demais áreas de cana-de-açúcar avaliadas. Os estoques de C e N foram maiores para as áreas em que o teor de argila foi superior; com queima e orgânica-4. Devido as diferenças entre texturas foram calculados os estoques em função dos ajustes quanto à massa de solo e teores de argila, utilizando-se como referência a vegetação nativa. Dessa forma os maiores estoques foram observados para o manejo orgânica-12. Os resultados para o conteúdo de C da biomassa microbiana (C-BM) mostrou aumento dos em função da melhoria do manejo. Em relação aos teores de C e N das frações da MOS, os manejos orgânicos (orgânica-12 e -4) resultaram nos maiores valores observados, principalmente para a fração organomineral <53 ?m à 5 cm de profundidade. Tais resultados refletiram diretamente sobre os valores de 13C, sua respectiva proporção de C derivado do resíduo C4 e, do 15N, indicando, respectivamente, maior acúmulo e proporção de C proveniente da cultura de canade- açúcar nas frações da MO, além de evidenciar, a partir do 15N, comportamento, quanto ao grau de humificação da MO, mais próximo ao observado para a vegetação nativa. Os resultados do estudo de modelagem enfatizaram a importância da textura do solo bem como as práticas de manejo para o acúmulo de C no solo. Os sistemas de manejo conservacionistas ao contrário da queima resultaram em estoques de C superiores em 78 % e 98 %, quando simulado solo com maior e menor teores de argila, respectivamente. Os resultados suportaram o uso do modelo Century em aplicações práticas de acúmulo de C em solos cultivados com cana-deaçúcar, principalmente, para os estoques de C e os ?13C dos solos avaliados, indicando que o modelo Century pode ser uma importante ferramenta para estabelecer estratégias apropriadas de manejo para aumentar os estoques de C do solo ao longo do tempo. O longo período de avaliação mostrou que conceitos, como o \"steady state\" de C no solo, podem ser investigados via modelagem, como pelo uso do modelo Century. A partir desse estudo foi possível concluir que práticas de manejos conservacionistas tendem a aumentar os estoques de C e N do solo ao longo do tempo e, que esse aumento é fortemente influenciado pelo teor de argila no solo. / One of the main obstacles of sugarcane production in the soil sustainability is the crop management and harvesting. The aim of this study was to evaluate the carbon (C) stocks and dynamics in different SOM fractions in sugarcane systems with or without burning, and under organic fertilization with different periods of adoption (4 and 12) and an area of native vegetation (Cerradão) used as a reference. The study areas are located in Goianésia, GO, all representatives of Latossolos Vermelho-Amarelo distróficos (Oxisols Hapludox distrofic). We evaluated C and N soil contents and natural isotopic abundances 13C e 15N to organominerals fractions < 53 ?m, 75-53 ?m e 2000-75 ?m (organic and organomineral fractions) of SOM. With these results, we aimed to simulate the maximum accumulation of C, by using the Century model, emphasizing different management practices and contrasting soil textures. The C contents were higher for organic-4, in relation to the other areas of sugarcane evaluated. The stocks of C and N were higher for areas where the clay content was higher (burning and organic-4). Due to the difference between soil texture we calculated stocks according to the adjustments on the equivalent mass of soil and clay content, with reference to the native vegetation and thus the largest stocks were observed for organic-12. The C from microbial biomass (C-BM) showed increased in the (C-BM) levels, due to improved management. Regarding the levels of C and N fractions of SOM, the organic-12 and organic-4 resulted in the highest values, especially for OM fraction < 53 ?m (organomineral) to 5 cm depth. These results reflected directly on the values of 13C, the respective proportion of C derived from C4 residue and the 15N, indicating, respectively, greater accumulation and proportion of C derived from the sugarcane in SOM fractions, and evidence from the 15N closer behavior to that observed for native vegetation, relative of OM humification degree. The results of the modeling study emphasized the importance of soil texture and management practices for soil C accumulation. The conservation management system resulted in higher C stocks, by 78% and 98% when simulated soil with higher and lower clay contents, respectively. The results supported the use of the Century model in practical applications of C accumulation in soils cultivated with sugarcane, especially for C stocks and 13C of soils evaluated, indicating that the Century model can be an important tool to establish appropriate management strategies to increase soil C stocks over time. The long period of evaluation showed that concepts such as the \"steady state\" of soil carbon, can be investigated via modeling. We concluded that the practices of the conservation tillage systems tend to increase the stocks of C and N in the soil over time, and this increase is strongly influenced by the clay content in the soil.
112

Post Plasma Etch Residue Removal Using Carbon Dioxide Based Fluids

Myneni, Satyanarayana 06 November 2004 (has links)
As feature sizes in semiconductor devices become smaller and newer materials are incorporated, current methods for photoresist and post plasma etch residue removal face several challenges. A cleaning process should be environmentally benign, compatible with dielectric materials and copper, and provide residue removal from narrow and high aspect ratio features. In this work, sub-critical CO2 based mixtures have been developed to remove the etch residues; these mixtures satisfy the above requirements and can potentially replace the two step residue removal process currently used in the integrated circuit (IC) industry. Based on the chemical nature of the residue being removed, additives or co-solvents to CO2 have been identified that can remove the residues without damaging the dielectric layers. Using the phase behavior of these additives as a guide, the composition of the co-solvent was altered to achieve a single liquid phase at moderate pressures without compromising cleaning ability. The extent of residue removal has been analyzed primarily by x-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Various techniques such as attenuated total reflection - Fourier transform infrared (ATR-FTIR) spectroscopy, angle-resolved XPS (ARXPS), and interferometry were used to probe the interaction of cleaning fluids with residues. Model films of photoresists and plasma deposited residues were used to assist in understanding the mechanism of residue removal. From these studies, it was concluded that residue removal takes place primarily by attack of the interface between the residue and the substrate; a solvent rinse then lifts these residues from the wafer. It has been shown that transport of the additives to the interface is enhanced in the presence of CO2. From positronium annihilation lifetime spectroscopy (PALS) studies on a porous dielectric film, it has been shown that these high pressure fluids do not cause significant changes to the pore sizes or the bonding structure of the film. Hence, this method can be used to remove post etch residues from low-k dielectric films.
113

PROPOSTA DE UM MODELO DE GESTÃO DE RESÍDUOS DE SERVIÇOS DE SAÚDE PARA OS HOSPITAIS DA QUARTA COLÔNIA/RS / PROPOSAL OF A MANAGEMENT MODEL OF HEALTH SERVICE RESIDUES TO QUARTA COLÔNIA`S HOSPITAL/RS

Calegare, Leandra 31 August 2007 (has links)
In the last decades, the discussion about generation of residues related to the environmental questions has been object of study of many researches. The health service residues (HSR) represent a bit portion of urban residues, but due to their especial characteristics, they are seen as problems that involve, besides the environmental plan, other areas of society as public health, basic sanitation, quality of population life and, for that reason, they deserve especial cares from their generation to final disposal. The present work aims to propose a Model of Management of Health Service to Quarta Colônia`s hospital, in Rio Grande do Sul, starting from the diagnosis of situation accomplished in the seven hospitals in Quarta Colônia that were working in the month of march, 2007. The methodology applied was the kind exploratory descriptive quantitative and qualitative, with multicase technique. The data collect was through non-structured interview, application of questionnaire and application blank that were answered by professionals responsible for the planning of Management System of HSR in the hospitals that were diagnosticated. Aiming to confirmation and validation of the supplied information through non-structured interviews, questionnaires and application, photographic records, observations in the files were accomplished. The collected and analyzed data showed possibilities of improvement before non-conformities and necessities in the handling system of HSR used by the hospitals in Quarta Colônia. The proposed model consists on a set of actions to the management of health service residues aiming to quality and efficiency of services developed by hospitals in Quarta Colônia, as well as in other similar hospitals, Besides it promotes the social environmental sustainability, because the actions proposed in the model reflect in benefit to the institution, to the environment and to the society. / Nas últimas décadas, a discussão sobre a geração dos resíduos relacionados às questões ambientais tem sido objeto de estudo de muitas pesquisas. Os Resíduos de Serviços de Saúde (RSS) representam uma pequena porção dos resíduos urbanos, mas devido às suas características especiais são vistos como problemas que envolvem, além do plano ambiental, outras áreas da sociedade, como a saúde pública, o saneamento básico e a qualidade de vida da população e, por isto, merecem cuidados especiais, desde a sua geração até a disposição final. Este estudo teve como objetivo propor um Modelo de Gestão de Resíduos de Serviços de Saúde para os hospitais da Quarta Colônia/RS, a partir do diagnóstico situacional realizado nos sete hospitais em operação no mês de março de 2007. A metodologia utilizada foi do tipo exploratória descritiva quantitativa e qualitativa, com técnica de multicaso. A coleta dos dados se deu mediante realização de entrevista não-estruturada, aplicação de questionário e formulário, os quais foram respondidos pelos profissionais responsáveis pelo planejamento do Sistema de Gestão de RSS dos hospitais diagnosticados, compondo a amostra deste estudo. Visando a confirmação e validação das informações fornecidas através da entrevista nãoestruturada, do questionário e do formulário, foram realizados registros fotográficos, observações no ambiente hospitalar, consultas a documentos e arquivos informatizados. Os dados coletados e analisados demonstraram possibilidades de melhorias frente às não conformidades e necessidades evidenciadas no sistema de manejo dos RSS adotado pelos hospitais da Quarta Colônia. O Modelo proposto constitui-se num conjunto de ações para o gerenciamento de resíduos de serviços de saúde visando à qualidade e eficiência dos serviços desenvolvidos pelos hospitais da Quarta Colônia bem como em outros hospitais de características semelhantes. Além disso, esse modelo promove a sustentabilidade ambiental-social, pois as ações estabelecidas no modelo repercutem em benefícios para a instituição, para o meio ambiente e para a sociedade.
114

Tecnologias verdes: mecanismo de efetivação da Política Nacional de Resíduos Sólidos aplicadas ao setor agrícola. / Green technologies: mechanisms of effectiveness the objectives of the National Policy of Solid Residue rural in activities such

Oliveira, Greice Kelly Lourenço Porfírio de 04 April 2017 (has links)
Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2017-05-11T11:14:09Z No. of bitstreams: 2 Dissertação - Greice Kelly Lourenço Porfírio de Oliveira - 2017.pdf: 1337783 bytes, checksum: 75d85b6e221e1a5bb9798a11d66c1afb (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-05-11T11:14:22Z (GMT) No. of bitstreams: 2 Dissertação - Greice Kelly Lourenço Porfírio de Oliveira - 2017.pdf: 1337783 bytes, checksum: 75d85b6e221e1a5bb9798a11d66c1afb (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-05-11T11:14:22Z (GMT). No. of bitstreams: 2 Dissertação - Greice Kelly Lourenço Porfírio de Oliveira - 2017.pdf: 1337783 bytes, checksum: 75d85b6e221e1a5bb9798a11d66c1afb (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-04-04 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This present study has as its general theme, the study of environment friendly green technologies, which were applied to rural activities such as mechanisms of effectiveness pertaining to the objectives of the National Policy of Solid Residue adhering to the following line of study: Agro-Food Law, Territories and Development. The study will begin from law 12.305/10 denominated as National Policy of Solid Residue. In this bias, a reflection shall be made about the use of green technologies, such as techniques that are able to meet the objectives that were created by the National Policy of Solid Residue, in reference to incentives towards the creation of clean technology, treatment, reutilization and adequate disposal of solid residue in the agriculture sector; which are described in article 7 of the referred law, aiming towards harmony in the national and sustainable technological development. / A presente pesquisa tem como tema geral o estudo de tecnologias verdes ambientalmente amigáveis, aplicadas em atividades rurais como mecanismo de efetivação dos objetivos da Política Nacional de Resíduos Sólidos se enquadrando na linha de pesquisa Direito Agroalimentar, Territórios e Desenvolvimento. O estudo se realizará a partir da Lei 12.305/10 denominada de Política Nacional dos Resíduos Sólidos. Nesse viés, far-se-á uma reflexão acerca da utilização das Tecnologias Verdes como técnicas capazes de atender aos objetivos traçados pela Política Nacionais Resíduos Sólidos no que tange ao incentivo a criação de tecnologias limpas, bem como o tratamento, reutilização e descarte adequado de resíduos sólidos no setor agrícola, os quais são descritos no artigo 7º da referida Lei, visando à harmonia do desenvolvimento tecnológico sustentável nacional.
115

Otimização da produção de β-xilosidase por Aspergillus fumigatus / Optimization of β-Xylosidase production by aspergillus fumigatus

Vieira, Fabíola Giovanna Nesello 10 June 2014 (has links)
Made available in DSpace on 2017-07-10T19:23:47Z (GMT). No. of bitstreams: 1 Fabiola G_ Nesello Vieira.pdf: 1352690 bytes, checksum: dde9077ce35994c9a408a58112929a03 (MD5) Previous issue date: 2014-06-10 / The abundant lignocellulosic biomass in agro-industrial waste can be reused as an inexpensive substrate for inducing the production of enzymes such as β-xylosidases. The purpose of this study was to analyze the production of β-xylosidase from Aspergillus fumigatus (PC-7S-2 M), isolated from the Atlantic Forest of the Dog Head State Park (Paraná, Brazil) and later identified by morphological and molecular (ITS) methods. The mesophilic fungus was grown at 28 °C in liquid culture media containing Czapeck and 1% of different agroindustrial residues (w/v): passion fruit peel, Ponkan peel, barley brewing residue, soy flakes and ripe banana peel. Inoculants of 105 conidia ml-1 were incubated for 7 days, filtered and assayed for β-xylosidase intracellular activity obtaining a maximum value of 15 U ml-1 of the enzyme in the presence of barley brewing residue after 4 days of cultivation. Then, it was used a Central Composite Rotational Design (CCRD) to optimize the production of β-xylosidase, using barley brewing residue as carbon source at a significance level of p<0.10 which generated a predicted model of 245.04 U ml-1. Model validation provided an average optimized result equal to 229.06 U ml-1 for the enzyme. Thus, the production of β-xylosidase increased in 1,500% over the initially obtained for A. fumigatus in the presence of the barley brewing residue, therefore, achieving 93.47% of the predicted model. This finding emphasizes the availability of A. fumigatus β-xylosidase production with possible applications in several biotechnological process. / A biomassa lignocelulósica abundante nos resíduos agroindustriais, pode ser reutilizada como substrato barato para induzir a produção de enzimas, como β-Xilosidases. O objetivo deste trabalho foi analisar a produção de β-Xilosidase de Aspergillus fumigatus (PC-7S-2 M), isolado da Mata Atlântica do Parque Estadual Cabeça do Cachorro (Paraná, Brasil) e posteriormente identificado por métodos morfológicos e moleculares (ITS). O fungo mesofílico foi cultivado à temperatura de 28 °C em meios líquidos de cultura Czapeck, contendo 1% de diferentes resíduos agroindustriais (w/v): casca de maracujá, casca de pokan, bagaço de cevada, flocos de soja e casca de banana madura. Inóculos de 105 conídios mL-1 foram incubados durante 7 dias, filtrados e submetidos a dosagem de β-Xilosidase intracelular, obtendo-se um valor máximo de 15 U ml-1 para a enzima na presença de bagaço de cevada com 4 dias de cultivo. Assim, utilizou-se um delineamento composto central rotacional (DCCR) para otimizar a produção de -Xilosidase, usando o bagaço de cevada como fonte de carbono em um nível de significância p < 0,10, o qual gerou um modelo predito de 245,04 U ml-1. A validação do modelo forneceu um resultado otimizado médio igual a 229,06 U ml-1 para a enzima. Assim, a produção de β-Xilosidase aumentou em 1.500% em relação à obtida inicialmente para o fungo A. fumigatus na presença de bagaço de cevada como fonte de carbono (15 U ml-1), permitindo, deste modo, alcançar 93,47 % do modelo predito. Este achado ressalta a viabilidade de produção de β-Xilosidase de A. fumigatus com possíveis aplicações em vários processos biotecnológicos.
116

Exploring The Role Of The Highly Conserved Residues In Triosephosphate Isomerase

Samanta, Moumita 05 1900 (has links) (PDF)
This thesis discusses the structure-function studies on triosephosphate isomerase (TIM) from Plasmodium falciparum (Pf), directed towards understanding the roles of highly conserved residues by site derected mutagenesis. Chapter 1 provides an introductory overview to the relevant literature on triosephosphate isomerase. In addition, this Chapter provides an analysis of conserved residues in TIM, and amino acid diversity at specific positions in the structure using a dataset of 503 TIM sequences. Chapter 2 reports the work on the completely conserved residue, C126 in TIM, which is proximal to the active site. Five mutants, C126S, C126A, C126V, C126M and C126T have been characterized. Crystal structures of 3-phosphoglycolate (PGA) bound C126S mutant and the unliganded forms of the C126S and C126A mutants have been determined at a resolution of 1.7 Å to 2.1 Å. Kinetic studies reveal a ~5 fold drop in kcat for the C126S and C126A mutants, while a ~ 10 fold drop is observed for the other three mutants. All the mutants show reduced stability at lower concentration and higher temperature. Chapter 3 presents the kinetic and structural characterization for the E97Q and E97D mutants of Pf TIM. A 4000 fold reduction in kcat is observed for E97Q, 100 fold reduction for the E97D mutant, while a ~ 9000 fold drop in activity for the control mutant, E165A. A large conformational change for the critical K12 side chain is observed in the crystal structure of the E97Q mutant, while it remains unchanged in the E97D structure. The results are interpreted to invoke a direct role for E97 in the catalytic proton transfer cycle, eliminating the need to invoke the formation of the energetically unfavorable imidazolate anion at H95. Chapter 4 reports investigations with position 96 by the biochemical and structural characterization of single mutants, F96Y, F96A and the double mutants, F96S/S73A and F96S/L167V. F96Y showed ~100 fold drop in activity, F96A revealed ~10 fold drop in activity, while F96S/S73A showed 100 fold lower activity than that of the wild type enzyme. Interestingly, the double mutant F96S/L167V proved to be a partial pseudorevertant, showing 10 fold higher activity than the single mutant, F96S. Chapter 5 describes the cloning, and preliminary kinetic and biophysical characterization of the enzyme, Dm TIM. A survey of disease causing mutations in TIM and the relationship of these sites of mutation to the active site and the dimer interface of TIM is presented in this Chapter.
117

Prescription Tillage Implementation via Creation of an Agronomic Rule Set and ISOBus Class III Control System for Achieving Spatially Variable Tillage

Schroeder, Brittany A. 30 September 2019 (has links)
No description available.
118

Утилизация и переработка отходов производства керамической плитки : магистерская диссертация / Utilization and recycling of ceramic tile production waste

Сегаева, В. Э., Segaeva, V. E. January 2022 (has links)
Исследованы свойства побочных тонкодисперсных продуктов, возникающих при производстве керамической плитки, приведен обзор способов их дальнейшей утилизации, и разработана технология переработки этих материалов с целью получения новых продуктов. / The properties of fine-dispersed by-products arising in the production of ceramic tiles are investigated, an overview of ways of their further utilization is given, and a technology for processing these materials in order to obtain new products is developed.
119

Residue Associations In Protein Family Alignments

Ozer, Hatice Gulcin 24 June 2008 (has links)
No description available.
120

Single channel analysis of thiol binding to a putative site of alcohol action on the glycine receptor

Goldstein, Beth Erlichman 23 October 2009 (has links)
An alcohol and anesthetic binding pocket is hypothesized to exist among transmembrane domains of the α1 glycine receptor (GlyR). Prior work has shown that amino acid residue serine-267 plays a significant role in the enhancing effects of alcohol and anesthetics and is theorized to form part of an alcohol and anesthetic binding cavity among subunit transmembrane domains. Propyl methanethiosulfonate (PMTS), an alcohol-like thiol, was previously shown to bind to a cysteine residue introduced at position 267 (S267C) and this resulted in permanent enhancement of GlyR function. If ethanol is binding to residue 267 in wildtype GlyR to potentiate receptor function then we hypothesized that covalent thiol labeling would produce receptor enhancement by the same mechanisms as ethanol. Using outside-out patch single channel electrophysiology we determined the open and closed dwell-times and burst properties of S267C GlyR in the absence and presence of PMTS. The primary consequence of PMTS binding to S267C GlyR was an increase in the lengths of burst durations, paralleling the main effect of ethanol on wildtype GlyR. Our findings thus provide a new line of evidence suggesting that ethanol is exerting its enhancing effects on the GlyR through its interactions with amino acid residue 267 in the second transmembrane domain. / text

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