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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.
51

Viscoelastic Characterization of Vapor-Grown Carbon Nanofiber/Vinyl Ester Nanocomposites using a Response Surface Methodology

Drake, Daniel Adam 11 May 2013 (has links)
The effects of vapor-grown carbon nanofiber (VGCNF) weight fraction, applied stress, and temperature on the viscoelastic responses (creep strain, creep rate, and creep compliance) of VGCNF/vinyl ester (VE) nanocomposites were studied using a central composite design (CCD). The nanocomposite test articles were fabricated by high shear mixing, casting, curing, and post-curing in an open face mold under a nitrogen environment. Short-term creep/creep recovery experiments were conducted at prescribed combinations of temperatures (23.8 – 69.2 C), applied stresses (30.2 – 49.8 MPa), and VGCNF weight fractions (0.00 – 1.00 parts of VGCNF per hundred parts of resin, phr) determined from the CCD. The response surface models (RSMs) for predicting these viscoelastic responses were developed using the least squares method and an analysis of variance procedure. The response surface estimates indicate that increasing the VGCNF weight fraction decreases the creep resistance of the VGCNF/VE nanocomposites at high temperatures (46.5 – 69.2 C).
52

[pt] ENSAIOS EM ECONOMETRIA / [en] ESSAYS IN ECONOMETRICS

PRISCILLA BURITY 12 August 2020 (has links)
[pt] Este trabalho consiste de quatro artigos e esta dividida em duas partes distintas. A primeira esta relacionado a modelos de estrutura a termo estimados para países cujos títulos soberanos sao considerados sujeitos a default. A segunda parte é sobre crescimento e convergencia. No primeiro artigo da primeira parte, usamos um modelo de estrutura a termo afim sem arbitragem e escolhemos tres países da zona euro para esta analise: Espanha, Grécia e Itália. Notamos que a dívida do proprio país tem desempenhado um papel importante na ampliac¸ao recente dos spreads, sobretudo para a Grecia e Itália. Para a Espanha, o recente aumento dos spreads está sendo impulsionado principalmente pelas variaveis relacionadas com a Alemanha (entre as quais a dívida alemã e a mais importante entre eles), e estresse do mercado (representada por um índice alto rendimento). No segundo artigo da primeira parte, usamos um modelo de sem arbitragem para investigar os determinantes da estrutura a termo dos spreads soberanos brasileiros e as expectativas da taxa de cambio no Brasil. Nossos exercícios indicam que fatores ligados a economia brasileira tiveram uma contribuic¸ao positiva para os spreads 1999-2006 e, na maior parte deste período, os fatores ligados a economia dos EUA tiveram uma contribuição negativa. Desde o final de 2007, esse cenario inverteu. Além disso, apresentam-se evidências de que a melhoria na nossa indicador de solvência externa, juntamente com a melhoria no cenario de inflação, e o principal responsável pela redução de spreads a partir do meio de 2007. O primeiro artigo da segunda parte propoe uma abordagem semi-parametrica para controlar a heterogeneidade não observada em modelos de regressao linear. Utilizamos estimadores extremos de redes neuras e o modelo e ilustrado em uma aplicação para a convergência de renda per capita entre os municípios brasileiros. Finalmente, no segundo artigo da segunda parte, vamos explorar os desenvolvimentos recentes sobre a convergencia para a produtividade industrial. Encontramos que o crescimento da produtividade esta negativamente relacionado com a produtividade inicial, mas que países com instituições piores têm um nível de equilíbrio de produtividade mais baixo. A taxa de crescimento da produtividade tambem tem uma relação não monotonica com a abertura comercial e educação, sendo mais rápida nos extremos. / [en] This work consists of four chapters and is divided into two distinct parts. The first is related to models of the term structure estimated for countries whose sovereign bonds are considered defaultable. The second part is about growth and convergence. In the first article of the first part, we used a no- arbitrage term structure model and chose three eurozone countries for this analysis: Spain, Greece and Italy. We noted that the country s debt has played an important role in the recent expansion of spreads, especially for Greece and Italy. For Spain, the recent increase in spreads has been driven primarily by variables related to Germany (Germany s debt is the most important among them), and market stress (represented by a highyield index). In the second article of the first part, we use a no-arbitrage model to investigate the determinants of the term structure of sovereign spreads and the expectations of the exchange rate in Brazil. Our exercises suggest that factors related to the Brazilian economy had a positive contribution to the 1999-2006 spreads and, in most of the period, factors related to the U.S. economy had a negative contribution. Since late 2007, this scenario has inverted. Furthermore, we present evidence that the improvement in our external solvency indicator along with the improved inflation scenario are the main responsible for the reduction of spreads from the middle of 2007 on. The first article of the second part proposes a semi-parametric approach to control unobserved heterogeneity in linear regression models. We use extreme neurotic networks estimators and the model is illustrated in an application to the convergence of per capita income across Brazilian municipalities. Finally, in the second article of the second part, we explore recent developments on industrial productivity convergence. We find that productivity growth is negatively related to initial productivity, but that countries with worse institutions have lower level of productivity in equilibrium. The rate of productivity growth also has a nonmonotonic relationship with trade openness and education, being faster at the extremes.
53

[en] CURRENT SITUATION AND DEVELOPMENT PROSPECTS OF PLANNING AREA 3 OF RIO DE JANEIRO CITY / [pt] SITUAÇÃO ATUAL E PERSPECTIVAS DE DESENVOLVIMENTO DA ÁREA DE PLANEJAMENTO 3 DA CIDADE DO RIO DE JANEIRO

RAFAEL FERNANDES DOS SANTOS 05 August 2013 (has links)
[pt] A dispersão da mancha urbana das cidades provoca alto custo para toda a população, com a necessidade de investimentos em saneamento, transportes e equipamentos urbanos, além do problema da poluição e desmatamento causados por essa expansão. Em casos como o da cidade do Rio de janeiro, a mancha urbana ocupa praticamente todo o território municipal e se desenvolve em áreas ainda desprovidas de infraestrutura que suporte novos empreendimentos, enquanto outras, melhor estruturadas, ficam estigmatizadas por conceitos urbanos pejorativos e desprestigiadas pela sociedade - os seus chamados subúrbios, hoje conhecidos como Área de Planejamento 3. Formam-se, com isso, vazios urbanos em áreas próximas ao centro, que poderiam ser melhor aproveitados para termos um território mais compacto e poupador de recursos públicos. O atual Plano Diretor da cidade estabeleceu como zonas de incentivo áreas antes desprestigiadas, em quase toda a Zona Norte e parte da Zona Oeste, sendo um ponto de partida para reversão do atual quadro de crescimento desordenado e segregatório da cidade. / [en] Rio de Janeiro has had a fragmented model of expansion, where many new regions occupied not have transportation and sanitation infrastructure, and old areas, structured, tend to be disparaged and stigmatized as places of low social value. The effects on the city is catastrophic, affecting the routine of all the population and hindering the control of the territory by the government. While there were new areas to grow, the city took advantage of that. Many neighborhoods were born, evolved and died, while new spaces were created and encouraged. Came to Barra da Tijuca, the greatest example of how Rio de Janeiro has expanded to meet the desires of a particular group in search of a safe and elitist environment. Condos upper middle class were built and attracted people from all over the city and, in parallel, its sewage was dumped in the lagoons of the neighborhood. While a new Rio grew, much of the city was deteriorating, especially downtown and North Zone. In the central region, the idea of transferring downtown to Barra da Tijuca gained strength, with large companies moving into this new neighborhood. Modern buildings, wide open spaces and parking were the main differences between the two regions. In the residential aspect, concern for downtown was virtually nil. In the North Zone, with the increase of slums and violence, traditional neighborhoods were no longer the focus of the middle class carioca, with stagnating real estate investments over time and making the region passed by a process of forgetting his relevance within the context of the city, having his image associated with violence and crime. In areas called suburbian, the situation was even worse. The old industries have moved to other cities due to the daily violence of those neighborhoods, highlighting Benfica, Bonsucesso, Ramos and Penha, suffering a massive stagnation over the past decades. Associated with urban problems, prejudice was responsable for the not occupation of a large space in the city, well structured and located. But none of this was seen as a problem, but as a solution, because in Rio there were still many areas to grow and receive new residents, not being interesting recover and encourage the occupation of what had actually structure to receive new ventures. The thought of rejection of old areas and interest in new lasted nearly three decades and, as a consequence of this neglect, we have seen emerge an ancient and undervalued city and another one new and prosperous, resulting in a decentralized Rio and full of empty urban, increasingly dependent of transport, sanitation and opening new routes, generating costs for the entire population. Analyzing the urban area in Rio, in North Zone, we can see how there is a waste of urbanized areas, where there is a structured urban space, with transportation and sanitation system established, but underutilized and virtually without good projects being introduced. In certain parts of West Zone, investments are numerous, without a previous and efficient infrastructure that can receive all these investments. This is a contradiction. Currently known as Planning Area 3 (AP 3), a huge and discredited region in North Zone is in a strategic location, but is stigmatized by the media and society with pejorative concepts of class, who treats it like a suburb, but the application of that name ends up being contradictory, because, in Rio de Janeiro, this concept is associated with an etymology and not with a urban fact. There are in AP 3 urbanized neighborhoods and near downtown, but they are viewed negatively, often caused by so-called opinion leaders. AP 3 is the gateway of the city, with a strategic location to anywhere else in the city, state, country and abroad (the international airport is located there). It is the most populated area in the city and needs to be well treated, as a new investment option, regardless of titles assigned to it. With its proper use, we would have a less process of expansion toward the West Zone, giving to the Rio a efficient urban development, integrator and spending few public resources, resulting in a territory less dispersed and more egalitarian. The lack of investment in AP 3 has brought, besides the widespread abandonment, tragic consequences not only for the 38 per cent of the population carioca living there, but also for the entire city, which bears the overall expenditure of the municipality. Carioca population grew between 2000 and 2010 from 5,857,904 to 6,320,446 inhabitants, and the population density grew from 4880.37 to 5265.81 hab/square km. Analyzing the five planning areas, we observed a population growth across all APs in the nineties, but the representative of each one in the citys total population was redistributed. The AP 3, which concentrates most of the population of Rio, had a dicrease from 40.20 per cent to 37.96 per cent hab/square km, while the West Zone had a considerable increase in that number. The West Zone (Barra da Tijuca, Recreio dos Bandeirantes, Jacarepaguá e Vargens) is the area that received the most investments and incentives to be occupied, with only 14.39 per cent of the population residing there. There is still no efficient system of sewerage, transport, sidewalks and street paving. Nevertheless, we can see that area envolving more and more, causing a collapse not only within the limits of the West Zone, but also affecting the traffic throughout the city. In contrast, AP 3, with nearly 38 per cent of the municipal population, has been losing its representativity, due to the lack of policies to encourage the attraction of new residents and provide better services to the current. A city like Rio de Janeiro, where there is still no efficient mass transport, should be more compact and its residents served by quality services in short rays, eliminating the dependence on shifts that require the use of own vehicles. The consequences of urban sprawl is what we see nowadays, like the constant traffic jams, due to the dependence of vehicles from those who live in areas furthest from downtown, the high cost of deployment transportation system to meet these new areas, need for sanitation base infrastructure, paving and lighting. The big question is, if there is a region still largely in its horizontal and already endowed with infrastructure, as the AP 3, investments in development and attracting new residents would be a way to save public money and take advantage from the current urban area of the city, contributing to a truly sustainable development. Rio de Janeiro does not have more growth cluttered spaces and building in prime areas are increasingly rare. Seeing the AP 3 as a growth vector of Rio is an economical way to have an efficient and inclusive urban development. This need has been ratified by legislation through the Complementary Law 111/11, which determined the incentive of that area and some adjacent. AP 3, because of its size and diversity, demands varied solutions, but the common denominator is the need to stimulate the formal residential occupation, urbanization, retrenchment in slums, the recovery of peripheral areas to them, that has been assuming characteristics of informality, and improving the infrastructure and quality of the transport system. There are many obsolete and underutilized areas that will enable a transformation in the way of inhabiting the city. If there is a global awareness of the urban territory, either in Rio de Janeiro or any other city in the world, the concept of sustainable growth is meaningless, with neighborhoods rising, developing and dying, wasting past spending and future spending provoking. Cities can not continue with thoughts segregatórios class and should be properly used and maintained, valuing its past and controlling the growth process on expensive areas untouched, becoming an integrated environment and easy to be used and administered. Despite this negative picture, a more attentive enough to discover the enormous economic potential of the AP 3. The housing market in certain spots is heated and there are high expectations of its expansion with new public and private investments that are occurring. Life in neighborhoods still retains an aspect of good neighborliness, preserving a quality of life now lost in the more developed districts of the city. We can already notice a special attention to the region, with new public and private investment, with little prospect of improvement in visibility and consolidation of growth vector proposed by the current master plan.
54

Papel do gene da síndrome de Wiskott Aldrich (WASP) na leucemia mielóide crônica. / The role of Wiskott Aldrich syndrome protein (WASP) in the chronic myeloid leukemia.

Pereira, Welbert de Oliveira 04 November 2011 (has links)
Bcr-Abl é a tirosina quinase (TK) responsável por causar a Leucemia Mielóide Crônica (LMC). Os últimos estudos de follow-up mostram que apenas 50% dos pacientes tratados com a segunda geração de inibidores de TK atinge a remissão completa, o que significa que metade desses pacientes necessita de um algo melhor do que está disponível. Wiskott Aldrich Syndrome Protein (WASP) é um gene essencial para o bom desenvolvimento e função das células hematopoiéticas. Ante esse contexto, decidimos investigar se WASP poderia ter algum papel ou relevância na LMC. Em conclusão, Bcr-Abl suprime a expressão WASP por um mecanismo epigenético. A re-expressão de WASP torna as células mais suscetíveis à apoptose em resposta ao Imatinib. Sugerimos que a recuperação da expressão WASP deve ser discutida como estratégia para a terapia da LMC. / Bcr-Abl is the tyrosine kinase (TK) responsible for causing Chronic Myeloid Leukemia (CML). This fusion protein up- and down-regulates several genes and pathways, producing a strong resistance to apoptosis and a blockage of cell maturation in the hematopoietic compartment. The last follow-up studies provided that only 50% of the patients treated with second generation achieve complete remission, what means that one-half of these patients needs something better. Wiskott Aldrich Syndrome Protein (WASP) is an essential gene for the proper development and function of the hematopoietic cells. In the light of this background, we decided to investigate if WASP could have some role or relevance in the CML context. In conclusion, Bcr-Abl suppresses WASP expression by an epigenetic mechanism. The re-expression of WASP makes the CML cells more susceptible to apoptosis and contribute to respond to Imatinib. We suggest that recovery of WASP expression should be discussed as a new and additional strategy for CML therapy.
55

Forest and landscape restoration at Pontal do Paranapanema: ecological attributes of forest restoration in a coffee agroforestry system / Restauração da paisagem florestal no Pontal do Paranapanema: indicadores ecológicos em sistemas agroflorestais com café sombreado

Badari, Carolina Giudice 12 February 2019 (has links)
A direct consequence of disorganized human population growth and the indiscriminate use of natural resources are the reduction of area and the fragmentation of native ecosystems, as they transform into agricultural areas. In this scenario, agroforestry systems (AFS) may be an alternative to reconcile restoration, conservation and local agricultural production. However, there is a diversity of AFS, and its use as a forest restoration strategy is still uncertain, mainly because we lack evaluations based on ecological indicators from those systems. Thus, we compared ecological indicators measured in a coffee agroforestry system in the Pontal do Paranapanema with those inform conventional restoration plantings of the same age and with regional reference ecosystems. We measured natural regeneration density and richness; canopy cover by native species and aboveground biomass and compared among sites using an ANOVA, followed by Tukey\'s test for mean comparison. Aiming to understand the factors influencing the ecological indicators of forest restoration in coffee AFS, we performed generalized linear models (GLM) using density of coffee and native trees, biomass, percentage of animal-dispersed trees, distance to the nearest forest remnant and richness of tree species as predictor variables and percentage of canopy cover and density and richness of natural regeneration as response variables. The reference forests had the highest values for forest structure indicators, followed by AFS and finally by the conventional restoration plantings. However, we found a greater diversity of tree species planted in the AFS and a natural regeneration similar to that found in the reference ecosystems. Despite coffee density in the AFS negatively influencing natural regeneration, the coffee AFS had greater ecological performance than the conventional restoration, being a viable alternative for forest restoration. We conclude that AFS with coffee and native tree species play an important ecological role in the FLR in Pontal do Paranapanema, reconciling productivity with forest restoration. / Um reflexo direto do crescimento desordenado da população humana e das atividades antrópicas é a diminuição e a fragmentação da área ocupada por ecossistemas nativos e sua substituição por áreas agrícolas. Neste cenário, os sistemas agroflorestais (SAF) podem ser uma alternativa para conciliar restauração, conservação e produção agrícola local. No entanto, tendo em vista a diversidade de SAFs, sua adoção como estratégia de restauração florestal ainda carece de estudos que avaliem os níveis de indicadores ecológicos de cada sistema. Neste sentido, comparamos os indicadores ecológicos de sistemas agroflorestais com café e espécies arbóreas nativas no Pontal do Paranapanema, com os de plantios convencionais de restauração florestal de mesma idade (12-15 anos) e ecossistemas de referência regionais. Medimos a densidade e a riqueza da regeneração natural, a cobertura do solo por espécies nativas e a biomassa acima do solo e as comparamos entre as áreas pela análise de variância ANOVA seguida da comparação de médias pelo teste de Tukey. Buscando compreender os fatores que influenciam os indicadores ecológicos da restauração florestal no SAF, analisamos modelos lineares generalizados, tendo biomassa, porcentagem de árvores zoocóricas, distância do remanescente florestal mais próximo, densidades de café, riqueza e densidade de árvores nativas como variáveis preditoras, e porcentagem de cobertura do dossel, densidade e riqueza da regeneração natural como variáveis respostas. As florestas de referência tiveram os maiores valores para indicadores de estrutura florestal, seguidas pelos SAFs e pelos plantios convencionais de restauração florestal. Entretanto, encontramos elevada diversidade de espécies arbóreas nos SAFs e valores próximos aos das florestas de referência para a diversidade da regeneração natural. Embora a densidade de plantas de café influencie negativamente a regeneração natural, os SAFs apresentaram um melhor desempenho ecológico que as áreas de restauração convencional, correspondendo à uma alternativa viável para restauração florestal. Desta forma, concluímos que os sistemas agroflorestais estudados desempenham um papel ecológico importante na restauração da paisagem florestal no Pontal do Paranapanema, conciliando produção com restauração florestal.
56

Avaliação do comportamento de elementos traço essenciais e não essenciais em solo contaminado sob cultivo de plantas / Evaluation of the behavior of essential and non essential trace elements in contaminated soil under plants cultivation

Silva, Maria Ligia de Souza 30 October 2006 (has links)
A contaminação do solo é crescente no mundo. Há grandes extensões de áreas contaminadas com elementos traço, compostos orgânicos, organometálicos e elementos radioativos, que ocorrem em concentrações que podem representar perigo ambiental. O comportamento dos elementos traço em solos e sua fitodisponibilidade com conseqüente passagem para a cadeia alimentar tem sido extensivo objeto de estudos mundialmente. Com o objetivo de avaliar o comportamento dos elementos traço, essenciais e não essenciais, num solo contaminado avaliou-se a absorção pelas plantas, a fitodisponibilidade por extratores e a fração do solo na qual os elementos encontram-se ligados em maior quantidade. O presente trabalho constou de dois experimentos, ambos realizados em casa de vegetação do Departamento de Ciência do Solo da ESALQ/USP com delineamento inteiramente casualizados, nos quais se utilizaram amostras de solo contaminado acidentalmente com elementos traço e espécies de plantas de interesse econômico. Os experimentos foram conduzidos de Novembro de 2004 a Abril de 2005, utilizando 7 níveis de contaminação por elementos traço e duas culturas, arroz e soja. Foi realizada adubação NPK de modo a atender as necessidades básicas de cada cultura. As plantas foram conduzidas até maturação. As variáveis avaliadas foram: desenvolvimento e produção vegetal; quantidade absorvida e acumulada de Cd, Cu, Fe, Mn, Pb e Zn; teores totais (água régia) e teores disponível dos elementos traço pelo uso das soluções Mehlich-1, HCl 0,1 mol L-1, DTPA e Ácidos Orgânicos no solo e a disponibilidade desses elementos através da correlação dos teores disponível no solo com os teores em folha diagnóstico, folha em final de ciclo e sementes de arroz e soja; e os teores de elementos traço nas frações do solo. A soja e o arroz foram sensíveis aos níveis de contaminação por elementos traço disponíveis no solo, exibindo sintomas de fitotoxidez, principalmente pelo Zn, manifestados por clorose e inibição do crescimento das plantas, sendo que o arroz mostrou-se mais sensível do que a soja à presença desses elementos. Para a soja, os quatro extratores foram eficientes para Cd, Cu, Pb e Zn, tanto ao correlacioná-los com teor na folha diagnóstico quanto na folha no final do ciclo enquanto que para o arroz, os mais eficientes foram o Mehlich-1, HCl 0,1 mol L-1 e o DTPA para o Cd, Cu, Fe e Zn. Para o Mn apenas o DTPA foi eficiente. Para o Fe, os extratores se mostraram pouco eficientes. O extrator Ácidos Orgânicos foi mais eficiente na avaliação da fitodisponibilidade de Cd, Cu, Pb e Zn para soja. Os maiores teores de Cd, Cu, Mn e Zn no solo encontram-se nas frações com ligações químicas mais estáveis (ligados a óxidos e residual) sendo as frações trocável + solúvel e orgânica de menor representatividade em relação ao total encontrado. O Pb, apesar de predominar nas frações ligadas a óxidos e residual, oferece grande potencial de contaminação ambiental por também apresentar-se nas frações trocável + solúvel e orgânica em teores consideráveis. O mesmo ocorre com o Zn, para o qual os teores totais foram mais elevados. / The contamination of the soil is growing in the world. There are great expanses of soil polluted with trace elements, organic compounds, organometals and radioactive elements that appear in concentrations that can endanger the environment. The behavior of trace elements in soils and its phytoavailability with subsequent transport to the alimentary chain has been quite intensive object of studies worldwide. With the objective of evaluating the behavior of essentials and non essential trace elements in a polluted soil, it was evaluated the absorption of trace elements by plants, its phytoavailability by extractors and in which fraction of the soil the elements are present in larger amount. The present work consisted of two experiments, both done entirely in a greenhouse of the Department of Soil Science of ESALQ/USP, with experimental design entirely randomized, in which samples of soil accidentally contaminated with trace elements and species of plants of economical interest were used. The experiments were conducted from November, 2004 to April, 2005, using seven levels of contamination for each trace elements and two cultures, rice and soybean. Fertilization with NPK was done in order to assist the basic needs of each culture. The plants were grown until maturation. The variables evaluated were: development and vegetable production; absorbed and accumulated amount of Cd, Cu, Fe, Mn, Pb and Zn; In the soil were determined total concentrations (HNO3/ HCl 1:3) and concentrations available of the trace elements by the use of the solutions Mehlich-1, HCl 0,1 mol L-1, DTPA and Organic Acids and the availability of those elements through the correlation of the available concentrations in the soil with the concentrations in diagnostic leaf, leafs in end of the cycle and seeds of rice and soybean; and the concentrations of trace elements in fractions of soil. The soybean and the rice were sensitive to the levels of trace elements available in the soil, exhibiting phytotoxicity symptoms, mainly for Zn, manifested as chlorosis and inhibition of growth. The rice was more sensitive than the soybean to the presence those elements. For soybean, the four extractors were efficient for Cd, Cu, Pb and Zn, both for the correlation with concentrations in the leaf diagnosis and in the leaf in the end of the cycle, while for rice, the most efficient were Mehlich-1, HCl 0,1 mol L-1 and DTPA for the Cd, Cu, Fe and Zn. For Mn, only DTPA was efficient. For Fe, the extractors were not efficient. The extractor Organic Acids was more efficient in the evaluation of the phytoavailability of Cd, Cu, Pb and Zn for soybean. The largest concentrations of Cd, Cu, Mn and Zn in the soil are found in the fractions with stable chemical bounds (attached to oxides and residue) being the exchangeable fractions + soluble and organic of smaller representativeness in relation to the total found. The Pb, in spite of prevailing in the fractions liked to oxides and residue, offers great potential of environmental contamination since it is also present in the exchangeable + soluble and organic fractions in considerable concentrations. The same happens for Zn, for which the total concentration was higher.
57

Development of nano-graphene cementitious composites (NGCC)

Ilyas, Muhammad January 2016 (has links)
Ordinary Portland cement (OPC) is the main constituent of concrete works as a principal binder for aggregates and intrinsically transmits the brittleness into concrete through the formation of hydration crystals in the cement microstructure. A number of nano cementitious composites were developed in recent years to offset the brittleness with newly discovered nanomaterials and the most prevalent among those is the graphene oxide (GO). The main objective of this PhD research work is to develop nano graphene cementitious composites (NGCC) using low cost, two dimensional (2D) graphene nanoplatelets (GNPs) and one dimensional (1D) graphited carbon nanofibres (GCNFs) with unique conical surface morphology. The GNPs were sourced synthesised in an environmental friendly way via plasma exfoliation whereas, GCNFs were manufactured through catalytic vapour grown method. The project further investigated the effect of these nanomaterials in regulating the distinctive microstructure of cement matrix leading to enhance its mechanical properties. Three different types of high-performance NGCC namely NGCC-Dot, NGCC-Fnt and NGCC-CNF, are developed by activating pristine GNPs (G-Dot), functionalised GNPs (G-Fnt) and graphited nanofibers (G-CNFs) into the cement matrix respectively. It is found through various characterization and experimental techniques that both GNPs and GCNFs regulated the cement microstructure and influenced the mechanical properties of NGCC uniquely. A remarkable increase in the flexural and the tensile strength of newly developed NGCC has been achieved and that could be attributed to the formation of distinctive microstructure regulated by catalytic activation of these nanomaterials. The shape (1D, 2D) and unique morphology of these nanomaterials played a vital role in the mechanism of crystal formation to regulate the cement microstructure. Based on the observations of test results and comprehensive characterization, the possible mechanisms of crystal formation and development of distinctive microstructure of NGCC has been established which has then proceeded to the development of a physical model for NGCC development.
58

Estudo da participação dos receptores do tipo Toll-2 e Toll-4 e da molécula adaptadora MyD88 no desenvolvimento do diabetes auto-imune experimental. / The role of TLR-2, TLR-4 and MyD88 in the development of experimental autoimmune diabetes.

Sá, Carla Sandrina Rendall Moreira 14 August 2013 (has links)
O diabetes mellitus tipo 1 (DMT1) é uma doença autoimune caracterizada pela destruição das células b pancreáticas, por citocinas (IFN-g, IL-1b, e TNF-a) produzidas por macrófagos e linfócitos Th1. A participação de TLRs no desenvolvimento desta doença tem sido demonstrada, porém os mecanismos envolvidos são poucos elucidados. Neste trabalho avaliamos o papel de TLR-2, TLR-4 e molécula adaptadora MyD88 no desenvolvimento do DMT1 experimental induzido por múltiplas doses de estreptozotocina. Foi observada maior severidade do DMT1 em animais TLR-2 KO, elevada glicemia e acentuada perda de peso. Um maior infiltrado celular inflamatório, aumento da expressão de bax, caspase-3 e diminuição no número de ilhotas foram observados no grupo de animais TLR-2 KO. Interessantemente, uma diminuição significante na frequência de células T reguladoras foi verificada no baço dos animais TLR-2 KO diabéticos. A deficiência do TLR-2 resultou no desenvolvimento exacerbado do DMT1, sugerindo um importante papel dos TLR-2 na modulação da resposta imune desenvolvida nesta doença. / Type 1 diabetes (T1D) is an autoimmune disease characterized by pancreatic beta cell destruction by activated macrophages and Th1 lymphocytes. The role of TLRs has been demonstrated in this disease, however the mechanisms involved in this process have not yet been fully explained. We evaluated the role of TLR-2, TLR-4 and MyD88 adaptor molecule in the development of experimental autoimmune diabetes induced by multiple low-doses of streptozotocin in C57Bl/6 mice. TDM1 was more severe in TLR-2 KO mice, with higher blood glucose levels and weight loss. Increased cellular infiltrate, bax and caspase-3 expression was detected in the pancreatic islets of the diabetic TLR-2 KO group suggesting a greater destruction of pancreatic cells. Interestingly, a decreased number regulatory T cells was observed in the spleen of diabetic TLR-2 KO animals. Hence, TLR-2 receptor deficiency resulted in exacerbated development of experimental autoimmune diabetes, thereby suggesting an important role for this receptor in the modulation of the immune response developed in this disease.
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Efeito de doses do composto orgânico bokashi associado à thichoderma SP. Na produção e no controle da podridão radicular da melancia. / Effect of doses of bokashi organic compound associated with thichoderma SP. In the production and control of watermelon root rot.

LIMA FILHO, Pedro. 15 May 2018 (has links)
Submitted by Élida Maeli Fernandes Quirino (maely_sax@hotmail.com) on 2018-05-15T19:05:55Z No. of bitstreams: 1 PEDRO LIMA FILHO - DISSERTAÇÃO PPGSA PROFISSIONAL 2015..pdf: 6434890 bytes, checksum: 9a4103b5aeb74beaec1a4cefac1a1429 (MD5) / Made available in DSpace on 2018-05-15T19:05:55Z (GMT). No. of bitstreams: 1 PEDRO LIMA FILHO - DISSERTAÇÃO PPGSA PROFISSIONAL 2015..pdf: 6434890 bytes, checksum: 9a4103b5aeb74beaec1a4cefac1a1429 (MD5) Previous issue date: 2015-06 / A cultura da melancia pode ser afetada por diversos patógenos que atuam no sistema radicular das plantas, comprometendo a absorção e o transporte de água e nutrientes, interferindo nos processos vitais para o seu desenvolvimento. Os experimentos foram conduzidos no CCTA/UFCG, Campus de Pombal. O primeiro avaliou o efeito de diferentes doses (0,14mL, 28mL, 56mL e 112mL/planta) do composto orgânico Bokashi no controle da podridão radicular ocasionada por Fusarium spp. em duas etapas simultâneas utilizando solo estéril e não estéril em casa de vegetação, as doses foram aplicadas semanalmente utilizandos e a cultivar ‘Crimson Sweet’ que foi semeada em vasos contendo seis kg de solo argiloso, constituído de seis tratamentos com cinco repetições. Foi avaliada a população microbiana total do solo, colhido a 0, 30, e 60 dias após o plantio da melancia e a uma profundidade de aproximadamente 10 cm e próximo ao sistema radicular além da incidência e severidade da podridão radicular, e matéria fresca seca da parte aérea das plantas. O segundo experimento em campo avaliou as duas melhores doses do composto orgânico ‘Bokashi, (112ml e 56ml) do experimento anterior e outras doses (224ml e 0ml), assim distribuídos (T1 112ml com Trichoderma, T2 112ml sem Trichoderma, T3 56ml com Trichoderma, T4 56ml sem Trichoderma, T5 224ml com Trichoderma, T6 224ml sem Trichoderma, T7 0ml com trichoderma, T8 0ml sem Trichoderma) totalizando 8 tratamentos e cinco repetições onde foram avaliadas a incidência e severidade a podridão radicular, além das características agronômicas da cultura como acúmulo de massa das plantas, e produção total dos frutos e fisiológica como taxa fotossintética (A), condutância estomática (gs), transpiração (E) e concentração intercelular de CO2 (Ci), No estudo em casa de vegetação os tratamentos com dose de 56ml de bokashi associado ao Trichoderma e o que utilizou dose de 112ml de bokashi obtiveram resultado significativo na redução da Incidência de patógenos fúngicos em melancieiras plantadas em solo não estéril e na severidade da podridão radicular causada por Fusarium spp em solo estéril. Em campo a dose 112ml de bokashi associado ao Trichoderma obteve redução tanto na incidência de patógenos fúngicos quanto na severidade da podridão radicular em melancieiras. O bokashi associado ao Trichoderma obteve melhor controle na incidência e severidade de podridão radicular em melancieira. O bokashi e Trichoderma não interferiram no crescimento e produção da melancieira. O Trichoderma interferiu de forma negativa nas análises fisiológicas da melancieira, para a taxa fotossintética, condutância estomática, transpiração e concentração intercelular de CO2. Os tratamentos que utilizaram dose de 112ml e 56ml de bokashi sem a presença do Trichoderma foi a que apresentou um melhor incremento para taxa fotossintética e condutância estomática respectivamente, evidenciando a importância do bokashi no intuito de melhorar a resposta fisiológica da planta. / The culture of watermelon can be affected by various pathogens that act on the root system of plants, affecting the absorption and transport of water and nutrients, interfering in the processes vital to their development.The experiments were conducted in the CCTA / UFCG, Campus de Pombal. The first evaluated the effect of different doses (0,14mL, 28ml, 56ml and 112mL / plant) of Bokashi organic compound in the control of root rot caused by Fusarium spp. in two simultaneous steps using sterile soil and non-sterile in greenhouse doses were applied weekly using the watermelon cultivar 'Crimson Sweet' that was sown in pots containing six kilograms of clay soil, made up of six treatments with five repetitions. We evaluated total soil microbial population, collected at 0, 30, and 60 days after planting watermelon and to a depth of about 10 cm and close to the root system beyond the incidence and severity of root rot, dry and fresh matter of watermelon. The second field experiment evaluating the top two doses of organic compost 'Bokashi, (112ml and 56ml) of the previous experiment and other doses (224ml and 0ml), distributed as follows (with Trichoderma 112ml, 112ml without Trichoderma, with Trichoderma 56ml, 56ml without Trichoderma, with Trichoderma a 224ml, 224ml without Trichoderma, 0ml with Trichoderma, 0ml without Trichoderma) totaling eight treatments and five replications which were assessed the incidence and severity of root rot and the agronomic characteristics of culture as a mass accumulation of plants, photosynthetic rate (a), stomatal conductance (gs), transpiration (E) and intercellular CO2 concentration (Ci), fresh and dry matter of shoot and total production of fruits. In the study of greenhouse treatments with 56ml dose of Bokashi associated with Trichoderma and what used dose of 112ml of Bokashi achieved significant results in reducing fungal pathogens incidence in watermelon planted in non-sterile soil and severity of root rot Fusarium spp in sterile soil. In the field dose of 112ml Bokashi associated with Trichoderma achieved a reduction in both the incidence of fungal pathogens as the severity of root rot in watermelon. Bokashi associated with Trichoderma got better control the incidence and severity of root rot in watermelon.
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Estudo da participação dos receptores do tipo Toll-2 e Toll-4 e da molécula adaptadora MyD88 no desenvolvimento do diabetes auto-imune experimental. / The role of TLR-2, TLR-4 and MyD88 in the development of experimental autoimmune diabetes.

Carla Sandrina Rendall Moreira Sá 14 August 2013 (has links)
O diabetes mellitus tipo 1 (DMT1) é uma doença autoimune caracterizada pela destruição das células b pancreáticas, por citocinas (IFN-g, IL-1b, e TNF-a) produzidas por macrófagos e linfócitos Th1. A participação de TLRs no desenvolvimento desta doença tem sido demonstrada, porém os mecanismos envolvidos são poucos elucidados. Neste trabalho avaliamos o papel de TLR-2, TLR-4 e molécula adaptadora MyD88 no desenvolvimento do DMT1 experimental induzido por múltiplas doses de estreptozotocina. Foi observada maior severidade do DMT1 em animais TLR-2 KO, elevada glicemia e acentuada perda de peso. Um maior infiltrado celular inflamatório, aumento da expressão de bax, caspase-3 e diminuição no número de ilhotas foram observados no grupo de animais TLR-2 KO. Interessantemente, uma diminuição significante na frequência de células T reguladoras foi verificada no baço dos animais TLR-2 KO diabéticos. A deficiência do TLR-2 resultou no desenvolvimento exacerbado do DMT1, sugerindo um importante papel dos TLR-2 na modulação da resposta imune desenvolvida nesta doença. / Type 1 diabetes (T1D) is an autoimmune disease characterized by pancreatic beta cell destruction by activated macrophages and Th1 lymphocytes. The role of TLRs has been demonstrated in this disease, however the mechanisms involved in this process have not yet been fully explained. We evaluated the role of TLR-2, TLR-4 and MyD88 adaptor molecule in the development of experimental autoimmune diabetes induced by multiple low-doses of streptozotocin in C57Bl/6 mice. TDM1 was more severe in TLR-2 KO mice, with higher blood glucose levels and weight loss. Increased cellular infiltrate, bax and caspase-3 expression was detected in the pancreatic islets of the diabetic TLR-2 KO group suggesting a greater destruction of pancreatic cells. Interestingly, a decreased number regulatory T cells was observed in the spleen of diabetic TLR-2 KO animals. Hence, TLR-2 receptor deficiency resulted in exacerbated development of experimental autoimmune diabetes, thereby suggesting an important role for this receptor in the modulation of the immune response developed in this disease.

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