Submitted by Sara Ribeiro (sara.ribeiro@ucb.br) on 2017-04-17T14:20:44Z No. of bitstreams: 1 FernandaDantasAlmeidaTese2016.pdf: 2319400 bytes, checksum: f6fb411112df029c4bb77d8f3bb375bf (MD5) / Approved for entry into archive by Sara Ribeiro (sara.ribeiro@ucb.br) on 2017-04-17T14:20:57Z (GMT) No. of bitstreams: 1 FernandaDantasAlmeidaTese2016.pdf: 2319400 bytes, checksum: f6fb411112df029c4bb77d8f3bb375bf (MD5) / Made available in DSpace on 2017-04-17T14:20:57Z (GMT). No. of bitstreams: 1 FernandaDantasAlmeidaTese2016.pdf: 2319400 bytes, checksum: f6fb411112df029c4bb77d8f3bb375bf (MD5) Previous issue date: 2016-06-01 / Banking credit plays a key role for the economic development and, therefore, it is important to understand its dynamics and its actuation for the transmission of the monetary policy. Thus, this thesis consists of two studies that aim to understand the micro and macroeconomic behavior of bank credit, investigating the main determinants of bank credit as well as the interaction of the banking sector with other sectors of the economy. The microeconomic analysis aims to identify the major determinants of banking credit in the Brazilian economy, considering the influence of specific characteristics of the financial institutions and monetary policy in the period 2001 to 2012. This paper contributes with the literature by showing that there was no relevant impact from the macroeconomic environment on the credit supply in the analyzed period. The government has adopted a countercyclical credit policy mismatched from prevailing macroeconomic conditions. In turn, the macroeconomic analysis investigates the effects of credit risk for the financial intermediation and how this risk is transmitted to other agents in the economy. The DSGE model with financial frictions of Gertler and Karadi (2011) was modified to incorporate the risk of default given by the probability of non-payment of loans granted by the bank. This study contributes to the literature by deriving the probability of default of firms endogenously in the model, unlike most of the studies that assume it as exogenous. Moreover, as the model assumes two different interest rates for the two kinds of borrowers ("good" and "bad" payers), it allows the analysis of the impacts of the borrowers??? quality on the overall interest rate on loans. As a result, we identified a countercyclical default rate, which compensates the bank for the lost with ???bad??? payers. / O cr??dito banc??rio possui um papel fundamental para o desenvolvimento econ??mico de um pa??s e, por isso, ?? muito importante compreender sua din??mica e sua atua????o na transmiss??o da pol??tica monet??ria. Por essa raz??o, esta tese ?? formada por dois estudos que visam entender o comportamento do cr??dito banc??rio de forma micro e macroecon??mica, investigando os principais aspectos que o determinam, bem como a intera????o do setor banc??rio com os demais setores da economia. A an??lise microecon??mica buscou identificar empiricamente os determinantes do cr??dito banc??rio no Brasil, sob a ??tica da oferta, de modo a averiguar o efeito das estrat??gias dos bancos e evidenciar o impacto da pol??tica monet??ria sobre a oferta de cr??dito no per??odo de 2001 a 2012. Esse estudo constatou que n??o houve impacto do ambiente econ??mico sobre a oferta de cr??dito no per??odo analisado, dado que o governo adotou uma pol??tica credit??cia antic??clica descasada das condi????es macroecon??micas vigentes. Por outro lado, a an??lise macroecon??mica buscou investigar os efeitos do risco de cr??dito na intermedia????o financeira e como esses efeitos s??o repassados aos demais agentes da economia. Para tanto, utilizou-se o modelo DSGE com fric????es financeiras de Gertler e Karadi (2011), que foi modificado de modo a incorporar o risco de default dado pela probabilidade de n??o pagamento dos empr??stimos concedidos pelo banco. Esse estudo contribui com a literatura ao derivar a probabilidade de default das firmas endogenamente ao modelo, diferente de grande parte dos artigos que a tratam como uma medida ex??gena. Ademais, ao trazer duas taxas de juros distintas para diferentes tomadores de cr??dito, os ???bons??? e os ???maus??? pagadores, o modelo permite a an??lise de como a qualidade dos mutu??rios impacta na taxa de juros global dos empr??stimos. Como resultado, encontra-se uma taxa de default antic??clica, que funciona como uma compensa????o para o banco pelas perdas com os ???maus??? pagadores.

Made available in DSpace on 2015-04-14T14:34:03Z (GMT). No. of bitstreams: 1 453109.pdf: 543581 bytes, checksum: 3deedaa23ebae8f84f2f2a97da79a3a7 (MD5) Previous issue date: 2013-12-20 / This paper addresses tax, environmental and economic law, more precisely the use of environmental "extrafiscality" as a possible legal-economic tool to protect an ecologically balanced environment, considering the provisions in articles 225 and 170, item VI of the Federal Constitution, which set forth that everyone is entitled to an ecologically balanced environment and charge the public authorities and society at large with the duty of conserving and protecting it, including by means of different treatments according to the environmental impact of products and services and their manufacturing and supply processes. The approach method is inductive; the procedure method is monographic, and research techniques include review of the literature, legislation, jurists' works, and court decisions. The first part of the text is dedicated to examining the Social-Environmental State and the power to levy taxes, divided into two chapters that are necessary and complementary to understand the assignment of the extrafiscal role as a legal tool to foster environmental conservation. The second part of the paper investigates whether the environmental extrafiscality of taxes is constitutional, and outlines the limits of its application in the Brazilian socialenvironmental state in an effort to show that the extrafiscality may serve as a tool to implement the different economic treatment provided for in item VI, article 170 of the Constitution. Based on those premises, we finally look into the possible assignment of the environmental extrafiscal role to all existing taxes, without the need of creating new taxes. We also analyze if the taxable event is directly related to the externality produced in order to determine whether all taxes similarly lend themselves to helping protect the ecologically balanced environment or not. As the ultimate task, the thenconsolidated hypothesis of this thesis is applied to analyze the possibility of assigning the environmental extrafiscal role to the Brazilian vehicle tax and its environmental conservation potential. / A presente pesquisa abrange o direito tribut?rio, o ambiental e o econ?mico, mais precisamente o uso da extrafiscalidade ambiental como poss?vel instrumento jur?dico-econ?mico de defesa do meio ambiente ecologicamente equilibrado, tendo em vista o disposto nos artigos 225 e 170, inciso VI da Constitui??o Federal, os quais estabelecem que todos t?m direito ao meio ambiente ecologicamente equilibrado, impondo-se ao Poder P?blico e ? coletividade o dever de preserv?-lo e defend?-lo, inclusive mediante tratamento diferenciado conforme o impacto ambiental dos produtos e servi?os e de seus processos de elabora??o e presta??o.O m?todo de abordagem ? o indutivo, o do procedimento ? o monogr?fico e as t?cnicas de pesquisa envolvem pesquisa bibliogr?fica com acesso ? legisla??o, doutrina e jurisprud?ncia. A primeira parte do texto ? dedicada ao exame do Estado Socioambiental e ao poder de tributar, divididos em dois cap?tulos necess?rios e complementares para a compreens?o da atribui??o da fun??o extrafiscal como instrumento jur?dico para a promo??o da defesa do meio ambiente. A segunda parte do trabalho, volta-se ? investiga??o da constitucionalidade da extrafiscalidade ambiental dos impostos tra?ando os limites de sua aplica??o no estado socioambiental brasileiro, buscando demonstrar que a extrafiscalidade pode servir de instrumento para a implementa??o do tratamento econ?mico diferenciado previsto no inciso VI do artigo 170 da Constitui??o. Com base nessas premissas, verifica-se a poss?vel atribui??o da fun??o extrafiscal ambiental nos impostos existentes, sem a necessidade de criar-se novos impostos, analisando tamb?m se o fato gerador do imposto possui rela??o direta com a externalidade produzida para concluir se todos os impostos prestam-se da mesma forma para auxiliar na concre??o da defesa do meio ambiente ecologicamente equilibrado, ou n?o. Como tarefa derradeira, aplica a hip?tese desta Tese, ent?o consolidada, no sentido de demonstrar a poss?vel atribui??o da fun??o extrafiscal ambiental no IPVA brasileiro e suas potencialidades de defesa do meio ambiente.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-08-23T19:13:00Z No. of bitstreams: 1 2013 - Murilo Gon?alves J?nior.pdf: 1563339 bytes, checksum: f1420577d0e6931ab3a974f949d64cfd (MD5) / Made available in DSpace on 2017-08-23T19:13:00Z (GMT). No. of bitstreams: 1 2013 - Murilo Gon?alves J?nior.pdf: 1563339 bytes, checksum: f1420577d0e6931ab3a974f949d64cfd (MD5) Previous issue date: 2013-07-24 / CAPES / Green manuring with legumes is a technique which improves soil characteristics, contributing to its conservation and reducing the use of synthetic nitrogen fertilizer on farms. Leguminous shrubby species Tephrosia vogelii, Tephrosia sinapou and Crotalaria grahamiana are little known at Brazil, and as well as Cajanus cajan (pigeon pea), show potential for green manuring. Two experiments were conducted at Field conditions: the first one aimed to evaluate the growth of Tephrosia vogelii during 360 days, measuring its phenological characteristics and its agronomic performance as green manure. The second one aimed to evaluate the agronomic performance of Tephrosia vogelii, Tephrosia sinapou, Crotalaria grahamiana and Cajanus cajan. The first experiment was conducted in 2010, at Agroecological Farm, and the second one was conducted between October of 2012 and May of 2013, at Experimental Field of Embrapa Agrobiology, both placed at Serop?dica, Fluminense Lowland. At the first one, the experimental design was of randomized blocks, with four replications. The treatments consisted of 12 mensal samplings, with the evaluations of: plants height, stalk diameter, leaf area, amount of fresh and dry matter in different plant parts, nitrogen content and total amount in the shoot. At the second experiment, it was adopted the experimental design of randomized blocks, with four replications, to evaluate the agronomic performance of the four leguminous species, in relation to plants growth. The evaluated plant parameters were: plants height, stalk diameter, amount of fresh and dry matter, nutrient contents and amounts of macronutrients in the shoot, amount of litter deposited by the evaluated species, and weeds control. In the first experiment, 12 months after sowing Tephrosia vogelii, its plants presented 200 cm of height, 11.2 Mg ha-1 of shoot dry matter, with a ratio stalk/leaf 4, besides a total amount of 192 kg ha-1 of N, in the shoot. In the second experiment, at 210 days after sowing, the evaluated species presented mean values of 180 cm of height, 9.7 Mg ha-1 of shoot dry matter and e 151 kg ha-1 of N. Cajanus cajan deposited around 4.8 Mg ha-1 of dry matter of litter, and Tephrosia vogelii promoted lower suppression of weeds. Both evaluated species of Tephrosia and Crotalaria grahamiana presented desirable characteristics for green manuring, similarly to Cajanus cajan, at conditions of climate and soil of Fluminense Lowland. / A aduba??o verde com esp?cies leguminosas ? uma t?cnica que possibilita melhorias nas caracter?sticas do solo, conservando-o e reduzindo a necessidade de ingresso de nitrog?nio sint?tico industrial ?s unidades de produ??o. As esp?cies leguminosas arbustivas Tephrosia vogelii, Tephrosia sinapou e Crotalaria grahamiana s?o pouco conhecidas no Brasil, e assim como o Cajanus cajan (guandu), apresentam potencial para aduba??o verde. Foram conduzidos dois trabalhos experimentais sob condi??es de campo: o primeiro trabalho teve como objetivo avaliar o crescimento de Tephrosia vogelii ao longo de 360 dias, para aferir suas caracter?sticas fenol?gicas e o seu potencial agron?mico como adubo verde. J? o segundo experimento objetivou avaliar o desempenho agron?mico desta esp?cie e de Tephrosia sinapou, Crotalaria grahamiana e Cajanus cajan. O primeiro experimento foi conduzido no ano de 2010 na Fazendinha Agroecol?gica do Km 47 e o segundo foi conduzido entre outubro de 2012 e maio de 2013, no Campo Experimental da Embrapa Agrobiologia, ambos localizados em Serop?dica, Baixada Fluminense. No primeiro, o delineamento experimental adotado foi de blocos casualisados, com quatro repeti??es. Os tratamentos foram formados de 12 coletas mensais, em que se avaliou: a altura das plantas, o di?metro do caule, ?rea foliar, quantidade de mat?ria fresca e seca em diferentes partes das plantas, teor e quantidade de nitrog?nio (N) na parte a?rea das plantas. No segundo experimento foi adotado um delineamento experimental de blocos casualisados com quatro repeti??es, avaliando-se o desempenho das quatro esp?cies quanto ao crescimento das plantas, tendo como par?metros a altura e o di?metro do caule, a quantidade acumulada de mat?ria seca a?rea, os teores e acumula??o de macronutrientes na parte a?rea, a quantidade de serrapilheira depositada pelas esp?cies e a capacidade de supress?o de esp?cies de ocorr?ncia espont?nea. No primeiro experimento, ao final de 12 meses ap?s a semeadura as plantas de Tephrosia vogelii apresentaram 200 cm de altura, 11,2 Mg ha-1 de mat?ria seca a?rea com uma rela??o caule/folha 4, al?m de uma acumula??o total de N na parte a?rea de 192 kg ha-1. No segundo experimento, aos 210 dias ap?s a semeadura, as esp?cies apresentaram, em valores m?dios, 180 cm de altura, 9,7 Mg ha-1 de mat?ria seca a?rea e 151 kg ha-1 de N. Destaca-se que Cajanus cajan depositou cerca de 4,8 Mg ha-1 de mat?ria seca de serrapilheira, e sob a copa de Tephrosia vogelii observou-se menor controle da ocorr?ncia de esp?cies da vegeta??o espont?nea. Conclui-se que as duas esp?cies do g?nero Tephrosia e Crotalaria grahamiana estudadas apresentaram caracter?sticas desej?veis para inclus?o como adubos verdes, compar?veis a Cajanus cajan, quando avaliadas nas condi??es edafoclim?ticas da Baixada Fluminense.

The overall purpose of this study is to assess various market-based versus aid based approaches to financial autonomy for Dalit women in rural India and the goals and assumptions of the multiple stakeholders involved in each method (mainly, national and international NGOs, the state, and micro-finance organizations). I argue that approaches to income generation such as entrepreneurship, capital investment, and skill building, are based on similar objectives of economic agency, but ultimately lend to different results because of their varying assumptions about “women’s empowerment.” By separating these approaches into three methods of income generation based on their objective to promote either wages, labor, or capital, the political incentives of each stakeholder becomes more clear. The research presented in my literature review ultimately led me to predict that for Dalit women in India to experience financial autonomy, wage labor that produces immediate outcomes is a more viable route to overall empowerment than entrepreneurship due to its cultural constraints women fact. However, after analyzing my comparative case studies which focused on three different methods of handicraft and textile production facilitated through state, institutional, private stakeholders, I began to see how a a multiple-income generating approach, such as combining the resources of NGOs, micro-finance, and the state, reduces caste and gender barriers to entrepreneurship. Through a feminist and Marxist analysis, I assess the problems that occur when actors determine a blanket approach to empowering all women without considering their diverse contexts, and more specifically, how different identities and standpoints work to inform and oppress notions of empowerment. My interviews with experts in the field have led me to recommend that methods of income generation facilitated through grassroots Self Help Groups is the best way for rural, Dalit women to women to achieve economic agency.

<p>Soil bottles and soil slurry experiments were conducted to investigate the effect of some additives on the aerobic and anaerobic biodegradation of chlorinated aliphatic hydrocarbons; tetrachloroethylene (PCE), trichloroethylene (TCE) and dichloroethylene (DCE) in a contaminated soil from Startvätten AB Linköping Sweden. For the aerobic degradation study the soil sample was divided into two groups, one was fertilised. The two groups of soil in the experimental bottles were treated to varying amount of methane in pairs. DCE and TCE were added to all samples while PCE was found in the contaminated soil. Both aerobic and anaerobic experiments were conducted. For aerobic study air was added to all bottles to serve as electron acceptor (oxygen). It was observed that all the samples showed a very small amount of methane consumption while the fertilised soil samples showed more oxygen consumption. For the chlorinated compounds the expected degradation could not be ascertained since the control and experimental set up were more or less the same.</p><p>For the anaerobic biodegradation study soil slurry was made with different media i.e. basic mineral medium (BM), BM and an organic compound (lactate), water and sulphide, phosphate buffer and sulphide and phosphate buffer, sulphide and ammonia. To assure anaerobic conditions, the headspace in the experimental bottles was changed to N2/CO2. As for the aerobic study all the samples were added DCE and TCE while PCE was found in the contaminated soil. The sample without the soil i.e. the control was also given PCE. It was observed that there was no clear decrease in the GC peak area of the pollutants in the different media. The decrease in GC peak area of the pollutants could not be seen, this may be so because more susceptible microorganisms are required, stringent addition of nutrients and to lower the risk of the high concentration of PCE and petroleum products in the soil from Startvätten AB.</p>

Soil bottles and soil slurry experiments were conducted to investigate the effect of some additives on the aerobic and anaerobic biodegradation of chlorinated aliphatic hydrocarbons; tetrachloroethylene (PCE), trichloroethylene (TCE) and dichloroethylene (DCE) in a contaminated soil from Startvätten AB Linköping Sweden. For the aerobic degradation study the soil sample was divided into two groups, one was fertilised. The two groups of soil in the experimental bottles were treated to varying amount of methane in pairs. DCE and TCE were added to all samples while PCE was found in the contaminated soil. Both aerobic and anaerobic experiments were conducted. For aerobic study air was added to all bottles to serve as electron acceptor (oxygen). It was observed that all the samples showed a very small amount of methane consumption while the fertilised soil samples showed more oxygen consumption. For the chlorinated compounds the expected degradation could not be ascertained since the control and experimental set up were more or less the same. For the anaerobic biodegradation study soil slurry was made with different media i.e. basic mineral medium (BM), BM and an organic compound (lactate), water and sulphide, phosphate buffer and sulphide and phosphate buffer, sulphide and ammonia. To assure anaerobic conditions, the headspace in the experimental bottles was changed to N2/CO2. As for the aerobic study all the samples were added DCE and TCE while PCE was found in the contaminated soil. The sample without the soil i.e. the control was also given PCE. It was observed that there was no clear decrease in the GC peak area of the pollutants in the different media. The decrease in GC peak area of the pollutants could not be seen, this may be so because more susceptible microorganisms are required, stringent addition of nutrients and to lower the risk of the high concentration of PCE and petroleum products in the soil from Startvätten AB.

Submitted by Ronildo Prado (ronisp@ufscar.br) on 2017-08-01T19:59:42Z No. of bitstreams: 1 DissPAAB.pdf: 4100356 bytes, checksum: 348f90d1cf3911093faeec744c33f884 (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2017-08-01T19:59:54Z (GMT) No. of bitstreams: 1 DissPAAB.pdf: 4100356 bytes, checksum: 348f90d1cf3911093faeec744c33f884 (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2017-08-01T20:00:00Z (GMT) No. of bitstreams: 1 DissPAAB.pdf: 4100356 bytes, checksum: 348f90d1cf3911093faeec744c33f884 (MD5) / Made available in DSpace on 2017-08-01T20:00:08Z (GMT). No. of bitstreams: 1 DissPAAB.pdf: 4100356 bytes, checksum: 348f90d1cf3911093faeec744c33f884 (MD5) Previous issue date: 2015-06-03 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / The main goal of any captive breeding program consists is maximizing the conservation of genetic diversity. Groups kept in captivity are particularly susceptible to the loss of genetic diversity, inbreeding depression and adaptation to captivity, due to their small size. The genetic characterization of wild and captive populations is an important tool both to minimize these impacts and for the conservation of these species, since it enables the development of management strategies aimed at maintenance of genetic diversity. In this context, the main objective of the study was to evaluate genetic variability and paternity for animals of black lion tamarin from Centro de Primatología do Rio de Janeiro, Fundacão Parque Zoológico de Sao Paulo, Parque Ecológico de Sao Carlos and 14 specimen belonging to the Durrell Conservation Trust in England using 15 microsatellite loci. The results of the allelic richness and expected heterozygosity showed similar values of alleles numbers and heterozygosity when compared with other species of Callitrichidae. Factorial correspondence analysis (FCA) showed greater homogeneity among captive animals than wild animals from Capão Bonito. The captive groups showed no differentiation among them and high differentiation from the wild Capão Bonito population. The data obtained herein are fundamental to increase the knowledge in genetic aspects of tamarins and support breeding programs to prevent loss of genetic diversity and inbreeding. / Maximizar a conservação da diversidade genética é um dos principais objetivos de qualquer programa de reprodução em cativeiro. Por serem de pequeno tamanho, grupos mantidos em cativeiro são particularmente suscetíveis à perda de diversidade genética, depressão endogâmica e adaptação ao cativeiro. Na tentativa de minimizar tais impactos, a caracterização genética de populações de vida livre e de cativeiro, torna-se uma importante ferramenta para a conservação destas espécies, uma vez que possibilita o desenvolvimento de estratégias de manejo que visem à manutenção de níveis adequados de diversidade genética. Neste contexto o objetivo principal deste trabalho foi avaliar através de 15 loci microssatélites, os níveis de variabilidade genética e paternidade dos animais mantidos em cativeiro no Brasil, no Centro de Primatologia do Rio de Janeiro, Fundação Parque Zoológico de São Paulo, Parque Ecológico de São Carlos e 14 espécimenes que faziam parte do Durrell Conservation Trust na Inglaterra. Os resultados referentes à riqueza alélica e heterozigosidade esperada mostraram que há uma representação similar nos valores de alelos e heterozigosidade quando comparado com outras espécies de Calitriquídeos. A análise de correspondência fatorial (FCA) mostrou que os grupos em cativeiro do Brasil apresentaram maior homogeneidade, quando comparados a um grupo de vida livre proveniente da região de Capão Bonito (São Paulo) e aos 14 indivíduos que representam ao grupo em cativeiro do zoológico de Durrell. O alto grau de parentesco entre os animais em cativeiro evidencia baixa diferenciação entre os grupos pertencentes às diferentes instituições brasileiras estudadas. Os grupos de cativeiro do Brasil, no entanto, mostraram-se divergentes dos animais de Capão Bonito. As informações obtidas neste trabalho são fundamentais para aumentar o conhecimento sob aspectos genéticos dos micos-leões-pretos e subsidiar planos de reprodução assistida que visem minimizar a perda de diversidade genética e a endogamia.

Made available in DSpace on 2014-12-17T14:06:57Z (GMT). No. of bitstreams: 1 CarolineDV.pdf: 1162871 bytes, checksum: cfd19877b2a491c559d68283231f1117 (MD5) Previous issue date: 2008-04-09 / A frequently encountered difficulty in oral prosthetics is associated with the loss of metallic alloys during the melting stage of the production of metal-ceramic replacement systems. Remelting such materials could impar their use in oral rehabilitation due to loss in esthetics, as well as in the chemical, physical, electrochemical and mechanical properties. Nowadays, the Ni-Cr-Mo-Ti alloy is widely used in metal-ceramic systems. Manufacturers state that this material can be remelted without significant alterations in its behavior, however little has been established as to the changes in the performance of this alloy after successive remelting, which is common practice in oral prosthetics. Therefore, the objective of this study was to evaluate possible changes in the esthetics and associated properties of metalceramic samples consisting of Ni-Cr-Mo-Ti and dental porcelain. Three to five remelting steps were carried out. The results revealed that Ni-Cr-Mo-Ti can be safely used even after three remelting steps. Further remelting significantly affect the characteristics of the alloys and should not be recommended for the manufacture of metal-ceramic systems / Uma dificuldade frequente encontrada na pr?tese dent?ria est? associada com a perda de ligas met?licas durante o est?gio de fundi??o na confec??o de sistemas metalocer?micos. A refundi??o de alguns materiais pode impedir seu uso na reabilita??o oral devido ? perdas nas propiedades est?ticas, como tamb?m, nas qu?micas, f?sicas, eletroqu?micas e mec?nicas. Atualmente a liga Ni-Cr-Mo-Ti ? bastante usada em sistemas metalocer?micos. O fabricante afirma que esse material pode ser refundido sem causar significantes altera??es na sua qualidade, no entanto pouco foi estudado quanto ?s mudan?as nas propriedades dessa liga ap?s sucessivas fundi??es, como ? comum na pr?tica nos laborat?rios dent?rios. Com base nisso, o objetivo desse estudo foi avaliar poss?veis mudan?as est?ticas e das propriedades das amostras metalocer?micas fabricadas com a liga Ni-Cr-Mo-Ti e porcelana odontol?gica. De tr?s a cinco etapas de fundi??o foram realizadas. Os resultados revelaram que a liga Ni-Cr-Mo-Ti pode ser usada mesmo ap?s subemtida ? tr?s fundi??es. Refundi??es adicionais afetam significantemente as caracter?sticas da liga e n?o s?o recomendadas para a confec??o de sistemas metalocer?micos

Made available in DSpace on 2014-12-17T14:07:08Z (GMT). No. of bitstreams: 1 EricaNMGP_TESE.pdf: 149123 bytes, checksum: d13a2a775b94d69d52d9e403106d2117 (MD5) Previous issue date: 2011-06-01 / The development of activities the of oil and gas sector have promoted the search for suitable materials for cementing oil wells. In the state of the Rio Grande do Norte, the integrity of the cement sheath tends to be impaired during steam injection, a procedure necessary to increase oil recovery in reservoirs with low-viscosity oil. The geopolymer is a material that can be used as alternative cement, since it has been used in the production of fire-resistant components, building structures, and for the control of toxic or radioactive residues. Geopolymers result from condensation polymer alkali aluminosilicates and silicates resulting three-dimensional polymeric structures. They are produced in a manner different from that of Portland cement, which is made an activating solution that is mixed with geopolymer precursor. Among the few works studied allowed us to conclude that the pastes prepared with metakaolin as precursor showed better performance of its properties. Several studies show the addition of waste clay as a means of reducing cost and improving end of the folder properties. On this basis, the goal is to study the influence of the addition of ceramic waste in geopolymer paste. To develop the study of rheology tests were carried out, filtered, thickening time, compressive strength, free water, specific gravity and permeability, according to the American Pretoleum Institute (API). The results for all formulations studied show that the folders have high mechanical strength to a light paste; low filtrate volume, absence of free water, very low permeability, slurry, consistent with a light paste, and thickening time low that can be corrected with the use of a retardant handle. For morphological characterization, microstructural, physical, chemical and thermal tests were carried out by XRD, MEV, DTA, TG, FTIR. In the trial of XRD, it was found that geopolymer is an amorphous material, with a peak of crystalline kaolinite. In tests of TG / DTA, revealed the presence of a significant event, which represents the mass loss related to water, and also observed the reduction of weight loss by increasing the concentration of ceramic waste. In the trial of MEV, we found a uniform matrix without the presence of other phases. In the trial of FT-IR, we observed the presence of the band related to water. From all results it was determined that the optimum concentration range of use is between 2.5 and 5% of waste ceramic / O desenvolvimento das atividades do setor de petr?leo e g?s tem promovido a busca de materiais mais adequados para cimenta??o de po?os de petr?leo. No estado do RN, a integridade da bainha cimentante tende a ser prejudicada durante a inje??o de vapor, procedimento necess?rio para aumentar a recupera??o do petr?leo em reservat?rios com ?leo de alta viscosidade. O geopol?mero ? um material que pode ser utilizado como cimento alternativo, uma vez que vem sendo empregado na produ??o de componentes resistentes ao fogo, na constru??o de estruturas, e para o controle de res?duos t?xicos ou radioativos. Geopol?meros resultam da condensa??o polim?rica de aluminosilicatos e silicatos alcalinos originando estruturas polim?ricas tridimensionais. S?o produzidos de uma maneira distinta daquela do cimento Portland, onde ? feita uma solu??o ativadora que ? misturada ao precurssor geopolim?rico. Dentre os trabalhos estudados, alguns permitiram-nos concluir que as pastas preparadas com metacaulim como precursor apresentaram melhor desempenho de suas propriedades. V?rios estudos apresentam a adi??o de res?duos argilosos como forma de redu??o do custo final e melhoria das propriedades da pasta. Com base nisso, o objetivo do trabalho ? estudar a influ?ncia da adi??o de rejeito cer?mico em pastas geopolim?ricas. Para o desenvolvimento do estudo foram realizados testes de reologia, filtrado, tempo de espessamento, resist?ncia ? compress?o, ?gua livre, peso espec?fico e permeabilidade, de acordo com o American Pretoleum Institute (API). Os resultados encontrados para todas as formula??es demonstram que as pastas estudadas apresentam resist?ncia mec?nica elevada para uma pasta leve; volume de filtrado baixo; aus?ncia de ?gua livre; permeabilidade muito baixa; pasta flu?da, coerente com uma pasta leve; e tempo de espessamento baixo, que pode ser corrigido com a utiliza??o de um retardador de pega. Para caracteriza??o morfol?gica, microestrutural, f?sico-qu?mica, qu?mica e t?rmica, foram realizadas caracteriza??es por DRX, MEV, DTA, TG, FT-IR. No ensaio de DRX, verificou-se que o geopol?mero ? um material amorfo, com um pico cristalino de caulinita. Nos testes de TG/DTA, foi observado a presen?a de um evento significativo, que representa a perda de massa referente a ?gua, sendo observado tamb?m a redu??o da perda de massa com o aumento da concentra??o de rejeito cer?mico. No ensaio de MEV, encontrou-se uma matriz uniforme e nos espectros de FT-IR, observou-se a presen?a da banda referente ? ?gua. A partir de todos os resultados foi poss?vel determinar que a faixa de concentra??o ?tima de rejeito cer?mico para uso em pastas geopolim?ricas ? entre 2,5 e 5 %

Made available in DSpace on 2014-12-17T14:07:17Z (GMT). No. of bitstreams: 1 OsvaldoCS_TESE.pdf: 5419870 bytes, checksum: 262730b1c0403826588e3ca7137507e0 (MD5) Previous issue date: 2013-07-19 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The production of waste from urban and industrial activities is one of the factors of environmental contamination and has aroused attention of the scientific community, in the sense of its reuse. On the other hand, the city of Salvador/Ba, with approximately 262 channels, responsible for storm water runoff, produces every year, by the intervention of cleaning and clearing channels, a significant volume of sediments (dredged mud), and thus an appropriate methodology for their final destination. This study aims to assess the influence of incorporation of these tailings in arrays of clay for production of interlocked block ceramic, also known as ceramic paver. All the raw materials from the metropolitan region of Salvador (RMS) were characterized by x-ray fluorescence, x-ray diffraction, thermal analysis (TG and TDA), particle size analysis and dilatometry. With the use of statistical experimental planning technique, ternary diagram was defined in the study region and the analyzed formulations. The specimens were prepared with dimensions of 60x20x5mm?, by uniaxial pressing of 30 MPa and after sintering at temperatures of 900?, 1000? and 1100?C the technological properties were evaluated: linear shrinkage, water absorption, apparent porosity, apparent specifies mass, flexural rupture and module. For the uniaxial compression strength used cylindrical probe body with ? 50 mm. The standard mass (MP) was prepared with 90% by weight of clay and 10% by weight of Channel sediment (SCP), not being verified significant variations in the properties of the final product. With the incorporation of 10% by weight of manganese residue (PFM) and 10% by weight of the Ceramic waste (RCB) in the mass default, in addition to adjusting the plasticity due to less waste clay content, provided increased linear firing shrinkage, due the significant concentration of K2O, forming liquid phase at low temperature, contributing to decreased porosity and mechanical resistance, being 92,5 MPa maximum compressive strength verified. After extract test leachate and soluble, the piece containing 10% of the PFM, was classified as non-hazardous and inert material according to NBR10004/04 ABNT. The results showed the feasibility on using waste, SCP, RCB and PFM clay mass, at temperatures above 900?C, paver ceramic production, according to the specifications of the technical standards, so that to exceed the 10% of the PFM, it becomes imperative to conduct studies of environmental impacts / A produ??o de res?duos provenientes das atividades urbanas e industriais ? um dos fatores de contamina??o ambiental e tem despertado aten??o da comunidade cientifica, no sentido do seu reaproveitamento. Por outro lado, a cidade do Salvador/Ba, com aproximadamente 262 canais, respons?veis pelo escoamento de ?guas pluviais, produz todo ano, pela necessidade de interven??o de limpeza e desobstru??o de canais, um volume significativo de sedimentos (lama dragada), impondo dessa forma uma metodologia adequada para sua destina??o final. Este trabalho tem como objetivo avaliar a influ?ncia da incorpora??o desses rejeitos em matrizes de argila para produ??o de bloco intertravado cer?mico, tamb?m conhecido como paver cer?mico. Todas as mat?rias primas oriundas da Regi?o Metropolitana de Salvador (RMS) foram caracterizadas por fluoresc?ncia de raios -X, difra??o de raios -X, analise t?rmica (TG e TDA), analise granulom?trica e dilatometria. Com a utiliza??o da t?cnica estat?stica de planejamento experimental, foi definida em diagrama tern?rio a regi?o de estudo e as formula??es analisadas. Foram preparados os corpos de prova com dimens?es de 60x20x5mm3, por prensagem uniaxial de 30 MPa e, ap?s sinteriza??o nas temperaturas de 900?, 1000? e 1100?C, as propriedades tecnol?gicas avaliadas foram: retra??o linear, absor??o de ?gua, porosidade aparente, massa especifica aparente, m?dulo de ruptura ? flex?o. Para a resist?ncia ? compress?o uniaxial utilizou-se o corpo de prova cil?ndrico com ? de 50mm. A massa padr?o (MP) foi preparada com 90% em peso de argila e 10% em peso do sedimento de canais (SCP), n?o sendo verificadas varia??es significativas nas propriedades do produto final. Com a incorpora??o de 10% em peso do res?duo de mangan?s (PFM) e 10% em peso do rejeito cer?mico (RCB) na massa padr?o, al?m do ajuste da plasticidade, em fun??o de menor teor de argilominerais dos res?duos, proporcionou aumento da retra??o linear de queima, devido a significativa concentra??o de K2O, formando fase liquida em baixa temperatura, contribuindo para diminui??o da porosidade e aumento da resist?ncia mec?nica, sendo 92,5 MPa a m?xima resist?ncia ? compress?o verificada. Ap?s teste do extrato lixiviado e solubilizado, a pe?a contendo 10% do PFM, foi classificada como material n?o perigoso e inerte segundo NBR10004/04 da ABNT. Os resultados mostraram viabilidade na utiliza??o dos res?duos SCP, RCB e PFM em massa argilosa, em temperaturas acima de 900?C, para produ??o de bloco intertravado, paver cer?mico, de acordo com as especifica??es das normas t?cnicas, de forma que, para teores superiores a 10% do PFM, torna-se imperativo a realiza??o de estudos de impactos ambientais