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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.
1

An?lise dos gases da exaust?o em um motor diesel com inje??o Common Rail alimentado com diesel, biodiesel e suas misturas

Costa, Joel de Oliveira 31 October 2017 (has links)
Submitted by PPG Engenharia e Tecnologia de Materiais (engenharia.pg.materiais@pucrs.br) on 2017-12-26T10:44:28Z No. of bitstreams: 1 Joel_de_Oliveira_Santos_DIS.pdf: 2391365 bytes, checksum: 494fe700a3624e9b996ee073b4bc0283 (MD5) / Approved for entry into archive by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-12-26T19:01:58Z (GMT) No. of bitstreams: 1 Joel_de_Oliveira_Santos_DIS.pdf: 2391365 bytes, checksum: 494fe700a3624e9b996ee073b4bc0283 (MD5) / Made available in DSpace on 2017-12-26T19:06:12Z (GMT). No. of bitstreams: 1 Joel_de_Oliveira_Santos_DIS.pdf: 2391365 bytes, checksum: 494fe700a3624e9b996ee073b4bc0283 (MD5) Previous issue date: 2017-10-31 / The presente work aims to evaluate exhaust gas emissions and particulate matters in a diesel cycle engine. A Cummins ISB Maxi Power (EURO III) Ford F250 pickup truck with electronic commom rail fuel injection system was used to identify which blend achieves the best environmental performance without compromising power and torque. The exhaust gases (CO, NOx, SO2) and particulate matters in different engine operating regimes were analyzed using commercial diesel oil B7 (diesel oil with 7% biodiesel volume) and additions of biodiesel up to B100. The procedures used in the tests were based on the ESC (European Stationary Cycle) test of engines in chassis dynamometer. The dynamometer used was the BOSCH model FLA 203, in conjunction with a TESTO model 350 gas analyzer, a NAPRO model NA 9000 opacimeter, and a 24-channel Pro Model FUEL TECH Datalogger. The results showed that the carbon monoxide (CO) had a significant reduction of 57.22% with the engine running with B100 at 750 rpm and 84.39% at 2600 rpm in a regime of 75% of the maximum power compared to B7. Nitrogen oxide (NOx) had an increase of 145.43% with B100 at 2600 rpm. Sulfur dioxide (SO2) produced by the combustion of diesel S10, represents low values, reaching 0 ppm in any of the engine operating regimes operating with the blends. The power and torque of the engine had an increase of 2.85% and 2.81% with the B15 mixture compared to the B7 fuel, even with the B15 we can verify that the carbon monoxide (CO) had a reduction of 35.78%, nitrogen oxides (NOx) had an increase of 40.71% and opacity a reduction of 1.9%. / O presente trabalho tem como objetivo avaliar as emiss?es de gases de exaust?o e materiais particulados em um motor ciclo diesel. Foi utilizado um ve?culo caminhonete Ford, modelo F250, com motor Diesel Cummins ISB Maxi Power (EURO III), com gerenciamento eletr?nico de inje??o de combust?vel Commom Rail, buscando identificar qual mistura obt?m o melhor desempenho ambiental sem comprometer pot?ncia e torque. Foram analisados os gases de exaust?o CO, NOx, SO2 e material particulado em diferentes regimes de funcionamento do motor, utilizando o ?leo diesel comercial (B7 - ?leo diesel com 7% em volume de biodiesel) e percentuais de biodiesel at? B100. Os procedimentos utilizados nos testes foram baseados na norma ESC (European Stationary Cycle) de teste de motores em dinam?metro de chassi. O dinam?metro usado foi da marca BOSCH, modelo FLA 203, em conjunto com analisador de gases da marca TESTO, modelo 350, opac?metro da marca NAPRO, modelo NA 9000, e Datalogger da marca FUEL TECH, 24 canais, modelo Pro. Os resultados mostraram que o mon?xido de carbono (CO) teve uma redu??o de 57,22% com o motor operando com B100 em marcha lenta (750 rpm) e 84,39% na rota??o de 2600 rpm, comparado com B7. Os ?xidos de nitrog?nio (NOx) tiveram aumentos de 145,43% com B100 a 2600 rpm. O di?xido de enxofre (SO2) apresentou valores pr?ximos a 0 ppm em qualquer um dos regimes do motor. A pot?ncia e torque tiveram aumentos de 2,85% e 2,81% com B15 comparado com B7, e com B15 o mon?xido de carbono (CO) teve redu??o de 35,78%, os ?xidos de nitrog?nio (NOx) tiveram aumentos de 40,71% e a opacidade redu??o de 1,9%.
2

Estimativa das emiss?es de di?xido de carbono associadas ?s mudan?as no uso e cobertura da terra do bioma caatinga no Estado do Rio Grande do Norte

Mata, Maria das Vit?rias Medeiros da 18 June 2015 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-05-04T00:12:48Z No. of bitstreams: 1 MariaDasVitoriasMedeirosDaMata_TESE.pdf: 7412662 bytes, checksum: 92171dff274965d92df96d5da9e98a78 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-05-06T19:35:19Z (GMT) No. of bitstreams: 1 MariaDasVitoriasMedeirosDaMata_TESE.pdf: 7412662 bytes, checksum: 92171dff274965d92df96d5da9e98a78 (MD5) / Made available in DSpace on 2016-05-06T19:35:19Z (GMT). No. of bitstreams: 1 MariaDasVitoriasMedeirosDaMata_TESE.pdf: 7412662 bytes, checksum: 92171dff274965d92df96d5da9e98a78 (MD5) Previous issue date: 2015-06-18 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Esta pesquisa apresenta as estimativas das taxas de emiss?es de CO2 por mudan?as no uso e cobertura da terra (MUCT) no Bioma Caatinga do Estado do Rio Grande do Norte, que compreende uma ?rea de aproximadamente 52.810km2.Como ferramenta foi utilizando o modelo de emiss?es INPE-EM (INPE- Emission Model) do Instituto Nacional de Pesquisas Espaciais. O principal objetivo desta pesquisa foi adaptar o modelo de emiss?es INPE-EM (INPE- Emission Model) para quantificar as emiss?es de CO2 por MUCT na regi?o no per?odo entre 2000 - 2010. Na adapta??o do modelo, foram utilizados dados de desmatamento anuais entre 2000 e 2010, al?m de dados de biomassa e uma s?rie de par?metros dispon?veis na literatura, como a porcentagem de biomassa acima e abaixo do solo removida, a porcentagem de biomassa acima do solo ap?s o desmatamento que ser? queimada no primeiro ano, o ciclo de queimadas, o decaimento do corte, o n?mero de anos para o abandono de uma ?rea de agricultura, etc. Uma primeira base de dados entre 1900 e 1999 foi simulada para incluir as contribui??es do passado nos cen?rios de emiss?es. Os resultados permitiram a gera??o de uma base de dados in?dita das emiss?es de CO2 nessa regi?o com resolu??o espacial de 5 km x 5 km. Esta base de dados servir? para outros estudos regionais/globais de balan?o de carbono, contribuindo tamb?m para a melhoria de invent?rios de emiss?es da regi?o. Este trabalho ? de fundamental import?ncia para a modelagem da gera??o, transporte e deposi??o de poluentes na qu?mica da atmosfera, tanto para estudos ambientais a curto prazo quanto para estudos clim?ticos. O estudo poder? servir para tomadas de decis?es na pol?tica ambiental da regi?o e para an?lises de impactos da a??o antr?pica no Bioma Caatinga. / This research presents the estimates of emission CO2 rates from land use and its change in the Caatinga Biome of Rio Grande do Norte, which comprises an area of approximately 52.810 km2. The INPE - Emission Model (INPE-EM) for emission estimates. The main objective of this research was to adapt the model of INPE-EM to quantify CO2 emissions from land use and its change in the region in the period 2000-2010. For this, annual deforestation data from 2000 to 2010 was combined, as well as recent biomass data and a set of alternative parameters, such as percentage of above- and below ground biomass, fire cycle, slash decay rate, number of years it takes for agricultural land to be abandoned, etc., all based on the recent literature to adapt the model for the Caatinga biome. A first data base from 1900 to 1999 was simulated to include the past contributions of deforestation processes in the model. The results can be used for policy decision-making, to analyze the impacts of anthropogenic activities in the Caatinga biome and also will help improve regional emission inventories for atmospheric chemistry and climate modeling.
3

Emiss?es de N2O do solo de cana-de-a??car plantada com fungicida via solo e fertilizada com ureia / Emissions of N2O from a sugarcane soil planted with soil fungicide and fertilized with urea

Silva, Erika Caitano da 27 July 2015 (has links)
Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2017-09-26T17:06:38Z No. of bitstreams: 1 2015 - Erika Caitano da Silva.pdf: 1958258 bytes, checksum: 61fcc63494dc0f8b0966ba187b5280a0 (MD5) / Made available in DSpace on 2017-09-26T17:06:38Z (GMT). No. of bitstreams: 1 2015 - Erika Caitano da Silva.pdf: 1958258 bytes, checksum: 61fcc63494dc0f8b0966ba187b5280a0 (MD5) Previous issue date: 2015-07-27 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / The objective of this study was to evaluate the efficiency of a fungicide of the strobilurin group in reducing soil N2O production, a potent greenhouse gas, and a possible positive effect on the N use efficiency by sugarcane. Laboratory studies were conducted to evaluate the effect of fungicide in soil fertilized with N on N2O emissions, as well as greenhouse and field experiments to study the fungicide as controller of urea and ammonium nitrate induction of N2O emissions and as an enhancer of fertilizer N use efficiency by sugarcane. In addition to the monitoring of soil N2O fluxes with static chambers sugarcane leaves were collected for analysis of soluble forms of N and nitrate reductase activity together with plant parameters to estimate yield and the efficiency of fertilizer N use. Laboratory tests revealed the fungicide was capable of reducing soil N2O emissions. Regardless of N source, the fungicide did not affect the analyses of enzymes and plant N fractions in sugarcane, but there was a downward trend of N2O fluxes in the soil treated with urea in the greenhouse experiment. In the field experiment, N2O fluxes were 6 to 89 ?g N m-2h-1, 24 to 795 ?g N m-2h-1 and 27 to 508 ?g N m-2h-1 respectively to the control (no added N), urea and urea + fungicide treatments, indicating that N2O emissions were reduced in approximately 30% by the fungicide. The treatment with ammonium nitrate did not induce N2O emissions from soil. There was no significant difference between treatments in all analyses of soluble fractions and enzyme activity. Based on the dimensions of stalks, sugarcane yield was estimated at 190 Mg ha-1for the control treatment (without added N) and at 238 Mg ha-1 for urea treatment. The application of fungicide had no effect on yield. The use of fungicide reduced soil N2O emissions, but does not induce greater N use efficiency by sugarcane / O objetivo deste trabalho foi avaliar a efici?ncia de fungicida do grupo das estrobilurinas na redu??o da produ??o de N2O no solo, um potente g?s de efeito estufa, al?m de poss?veis efeitos positivos na efici?ncia de uso de N pela cana-de-a??car. Foram conduzidos estudos em laborat?rio para avaliar o efeito do fungicida em solo fertilizado com N sobre as emiss?es de N2O, assim como um ensaio em casa de vegeta??o e outro em campo, onde se estudaram a ureia e o nitrato de am?nio, tratados ou n?o com fungicida, sobre as emiss?es de N2O e indicadores de efici?ncia de uso de N pela cana-de-a??car. Al?m do monitoramento dos fluxos de N2O com c?maras est?ticas, foram tamb?m coletadas folhas da cultura para an?lise das fra??es sol?veis de N e an?lise da enzima nitrato redutase, incluindo-se tamb?m a estimativa da produtividade e efici?ncia do uso de N. Os ensaios de laborat?rio mostraram que o fungicida aplicado ao solo reduz emiss?es de N2O. No ensaio em casa-de-vegeta??o, a an?lise de enzimas e fra??es de N na cana-de-a??car n?os e alteraram com o uso do fungicida, independente da fonte de N, mas houve tend?ncia de redu??o dos fluxos de N2O no solo tratado com ureia. No ensaio de campo, os fluxos de N2O foram de 6 a 89 ?g N m-2h-1, 24 a 795 N m-2 h-1 e 27 a 508 N m-2 h-1respectivamente para os tratamentos controle (sem adi??o de N), ureia e ureia +fungicida, indicando queda nas emiss?es de N2O de aproximadamente 30% no tratamento com fungicida.O tratamento com nitrato de am?nio n?o induziu emiss?es de N2O do solo.N?o houve diferen?a significativa entre os tratamentos em todas as an?lises das fra??es sol?veis e tamb?m na an?lise enzim?tica. A produtividade de colmos (TCH), estimada a partir das dimens?es dos colmos, variou significativamente de 190 Mg ha-1, no tratamento controle (sem adi??o de N), para 238 Mg ha-1, no tratamento com ureia, por?m a aplica??o do produto n?o influenciou na produ??o da cultura. O uso de fungicida reduz emiss?es de N2O, por?m n?o induz maior efici?ncia de uso de N pela cana-de-a??car
4

Um estudo e an?lise do teste de emiss?es otoac?sticas realizadas atrav?s de uma plataforma m?vel

Barbalho, Talis Lincoln Fonseca 27 January 2014 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-01-26T18:48:33Z No. of bitstreams: 1 TalisLincolnFonsecaBarbalho_DISSERT.pdf: 1664415 bytes, checksum: 493607b79ab3c61b0e06559811f5034c (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-01-28T20:56:50Z (GMT) No. of bitstreams: 1 TalisLincolnFonsecaBarbalho_DISSERT.pdf: 1664415 bytes, checksum: 493607b79ab3c61b0e06559811f5034c (MD5) / Made available in DSpace on 2016-01-28T20:56:50Z (GMT). No. of bitstreams: 1 TalisLincolnFonsecaBarbalho_DISSERT.pdf: 1664415 bytes, checksum: 493607b79ab3c61b0e06559811f5034c (MD5) Previous issue date: 2014-01-27 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / O exame de emiss?es otoac?sticas foi criado para que pudesse ser realizado logo nos primeiros dias de vida da crian?a, ou at? no m?ximo com 6 meses de vida, pois determinados problemas se n?o forem superados podem causar danos neurol?gicos permanentes nessa ?rea da audi??o. Devido a import?ncia do exame na preven??o de doen?as auditivas, este exame tornou-se obrigat?rio em todo territ?rio nacional em 2010, atrav?s da Lei 12.303/10. Depois que a Lei foi aprovada no Brasil, foi necess?rio a compra de muitos equipamentos para tornar poss?vel a realiza??o do exame nas maternidades p?blicas do pa?s, mas o aparelho custa entre R$ 20.000,00 e R$ 30.000,00 reais. Assim, valor pode ser muito alto para compra de equipamentos para todas as ?reas do pa?s, principalmente para algumas menores cidades do interior. Dessa forma, esse trabalho ? inserido nesse contexto para auxiliar a obten??o dos testes em ?reas com mais dif?cil acesso, pois atrav?s de um celular ? poss?vel realizar o Teste da Orelhinha, em seguida, atrav?s de uma conex?o com internet ? poss?vel enviar esse Teste para uma central que possui o aplicativo que ir? verificar esses Testes e obter gr?ficos para uma melhor an?lise dos resultados pelos profissionais respons?veis da equipe m?dica.
5

An?lise experimental do consumo de um ve?culo flex operando com diferentes misturas de gasolina/etanol em tr?fego urbano

Lira, F?bio Pimenta de 30 November 2015 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-07-08T21:06:56Z No. of bitstreams: 1 FabioPimentaDeLira_DISSERT.pdf: 2588802 bytes, checksum: 309b81889459c9056d686910dd512bf9 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-07-12T19:50:05Z (GMT) No. of bitstreams: 1 FabioPimentaDeLira_DISSERT.pdf: 2588802 bytes, checksum: 309b81889459c9056d686910dd512bf9 (MD5) / Made available in DSpace on 2016-07-12T19:50:05Z (GMT). No. of bitstreams: 1 FabioPimentaDeLira_DISSERT.pdf: 2588802 bytes, checksum: 309b81889459c9056d686910dd512bf9 (MD5) Previous issue date: 2015-11-30 / O presente estudo trata de uma an?lise, em car?ter experimental, do consumo de combust?vel de um veiculo flex, operando com diferentes misturas de gasolina e etanol em tr?fego urbano, o que permite obter resultados mais condizentes com a realidade do motorista, haja vista que os ?ndices de consumo aferidos pelo INMETRO n?o levam em considera??o o real cen?rio que a popula??o enfrenta diariamente em seus deslocamentos urbanos, possibilitando assim a escolha mais economicamente vi?vel da mistura gasolina/etanol, acarretando numa redu??o dos custos e, possivelmente, uma diminui??o nos ?ndices de emiss?o de poluentes. Atualmente, os fabricantes de ve?culos flex recomendam o abastecimento com etanol, caso o valor deste n?o ultrapasse 70% do valor da gasolina comum, entretanto, os ve?culos com a tecnologia flex, possibilitam operar com qualquer percentual de mistura no tanque de combust?vel, por?m, hoje, muitos dos propriet?rios desses ve?culos n?o utilizam esse recurso com efici?ncia, por desconhecerem essa possibilidade de mistura ou pela raz?o de n?o existir um estudo mais profundo em rela??o ao percentual ideal da mistura que proporcione um maior rendimento com um custo inferior ao proposto pelos fabricantes. / This study is an analysis, on a trial basis, the fuel consumption of a Flex vehicle, operating with different mixtures of gasoline and ethanol in urban traffic, allowing more consistent results with the reality of the driver. Considering that most owners unaware of the possibility of mixing the fuel at the time of supply, thus enabling the choice of the most economically viable mixing gasoline / ethanol, resulting in lower costs and possibly a decrease in pollutant emission rates. Currently, there is a myth created by the people that supply ethanol only becomes viable if the value of not more than 70% of regular gasoline. However vehicles with this technology make it possible to operate with any percentage of mixture in the fuel tank, but today many of the owners of these vehicles do not use this feature effectively, because they ignore the possibility of mixing or the reason there is a deeper study regarding the optimal percentage of the mixture to provide a higher yield with a lower cost than proposed by the manufacturers.
6

An?lise preditiva a partir da caracteriza??o das emiss?es gasosas e do ?leo lubrificante em frotas com motoriza??o a diesel

Sousa, Eduardo Henrique Viana de 30 August 2010 (has links)
Made available in DSpace on 2014-12-17T14:58:03Z (GMT). No. of bitstreams: 1 EduardoHVS_DISSERT.pdf: 4888448 bytes, checksum: 16ede4f993cb59d4e084c847af90483e (MD5) Previous issue date: 2010-08-30 / This work was motivated by the importance of conducting a study of vehicle emissions in captive fleets with diesel engine, coupled with the predictive maintenance plan. This type of maintenance includes techniques designed to meet the growing market demand to reduce maintenance costs by increasing the reliability of diagnoses, which has increased interest in automated predictive maintenance on diesel engines, preventing problems that might evolve into routine turn into serious situations, solved only with complex and costly repairs, the Reliability Centered Maintenance, will be the methodology that will make our goal is reached, beyond maintaining the vehicles regulated as fuel consumption and emissions. To Therefore, technical improvements were estimated capable of penetrating the automotive market and give the inshore fleet emission rates of opacity of the vehicles, being directly related to the conditions of the lubricating oil thus contributing to reducing maintenance costs by contributing significantly to emissions of pollutants and an improvement in the air in large cities. This criterion was adopted and implemented, em 241 buses and produced a diagnosis of possible failures by the correlation between the characterization of used lubricating oils and the analysis of opacity, with the objective of the aid the detection and solution of failures for the maintenance of sub-systems according to design criteria, and for this to be a deductive methodology to determine potential causes of failures, has been automated to implement a predictive maintenance system for this purpose was used in our study a mobile unit equipped with a opacimeter and a kit for collection and analysis of lubricating oil and the construction of the network diagnostics, we used a computer program in Microsoft Office Access 2007 platform tool is indispensable for creating a database data, this method is being used and successfully implemented in seven (7) bus companies from the city of Natal (RN) Brazil / Este trabalho foi motivado pela import?ncia de realizar um estudo das emiss?es veiculares em frotas cativas com motoriza??o a diesel, associado ao plano de manuten??o preditiva. Esta modalidade de manuten??o engloba t?cnicas destinadas a atender a crescente exig?ncia do mercado em reduzir custos de manuten??o pelo aumento da confiabilidade dos diagn?sticos, o que fez crescer o interesse pelos sistemas automatizados de manuten??o preditiva nos motores a diesel, impedindo que problemas de rotina possam evoluir at? se transformarem em situa??es graves, solucion?veis apenas com repara??es complexas e dispendiosas, esta Manuten??o Centrada em Confiabilidade, ser? a metodologia que far? com que o objetivo seja atingido; al?m de manter os ve?culos regulados quanto ao consumo de combust?vel e emiss?o de poluentes. Para isso, estimaram-se melhorias t?cnicas capazes de penetrar no mercado automotivo e de conferir, nas frotas cativas, os ?ndices de emiss?o de opacidade dos ve?culos, sendo isso relacionado diretamente ?s condi??es do ?leo lubrificante, possibilitando a redu??o de custos de manuten??o, contribuindo de forma consider?vel com as emiss?es de poluentes e uma melhoria no ar das grandes metr?poles. Esse crit?rio foi adotado e implementado, em 241 ?nibus sendo produzido um diagn?stico das poss?veis falhas atrav?s da correla??o entre a caracteriza??o dos ?leos lubrificantes usados e a an?lise de opacidade, tendo como objetivo o aux?lio na detec??o e solu??o de falhas, visando ? manuten??o dos subsistemas segundo os crit?rios de projeto. Por ser esta uma metodologia dedutiva na determina??o de potenciais causas de falhas, foi automatizada para a implementa??o de um sistema de manuten??o preditiva; para esse fim foi utilizado nesse estudo uma unidade m?vel equipada com um opac?metro e um kit para coleta e analise do ?leo lubrificante; para a constru??o da rede de diagn?sticos foi utilizado um programa de computador em plataforma Microsoft Office Access 2007, ferramenta fundamental para a cria??o de um banco de dados, este m?todo est? sendo utilizado e implementado com sucesso nas sete empresas de ?nibus urbanos da cidade do Natal/RN, Brasil
7

Efeito do biodiesel no bico injetor e na emiss?o de material particulado em motor do ciclo diesel

Oliveira Filho, Manoel Fernandes de 13 May 2016 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-03-17T19:11:51Z No. of bitstreams: 1 ManoelFernandesDeOliveiraFilho_TESE.pdf: 19688011 bytes, checksum: 022c8d97d4f29f129508061cea3bc018 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-03-17T22:31:06Z (GMT) No. of bitstreams: 1 ManoelFernandesDeOliveiraFilho_TESE.pdf: 19688011 bytes, checksum: 022c8d97d4f29f129508061cea3bc018 (MD5) / Made available in DSpace on 2017-03-17T22:31:06Z (GMT). No. of bitstreams: 1 ManoelFernandesDeOliveiraFilho_TESE.pdf: 19688011 bytes, checksum: 022c8d97d4f29f129508061cea3bc018 (MD5) Previous issue date: 2016-05-13 / Bico injetor ? um importante componente do sistema de inje??o de um motor diesel respons?vel pela atomiza??o do combust?vel, por uma combust?o eficaz e uma baixa emiss?o de poluentes, a qual afeta diretamente o meio ambiente e o sistema cardiovascular humano. Os padr?es lim?trofes de emiss?es veiculares definidos pela legisla??o ambiental s?o crescentemente rigorosos, como o PROCONVE P7, no Brasil e a Euro 6, na Uni?o Europ?ia e restringem o tamanho do material particulado e NOx. O objetivo desta Tese foi investigar e compreender os mecanismos de desgaste de materiais fr?geis e d?cteis que se submetem ? a??o de um atomizador do tipo Common Rail, eros?o, cavita??o, ader?ncia, ades?o e corros?o. Desenvolveu-se um m?todo sistem?tico para avaliar biocombust?veis diesel, com aditivos ou obtido em postos, o seu processo de atomiza??o e sua intera??o com dois materiais estruturais, um quimicamente ativo, cobre eletrol?tico e um quimicamente inerte, vidro de ?xido de sil?cio. Um dispositivo equipado com uma c?mara de atomiza??o de alta press?o (HPSC), um dispositivo de ensaio de bico injetor e uma c?mera CCD foram usados na avalia??o do processo de atomiza??o. Nesta, foram ensaiados quatro fluidos: Ultrasene (fluido padr?o da m?quina TM 507); B6 aditivado com tensoativos; B6 com tensoativos e ?gua e B6 com tensoativos, ?gua e glicerina. Uma bancada dinamom?trica foi utilizada nos ensaios dos motores estacion?rio diesel monocil?ndrico, marca Branco BD 5.0, quatro tempos, de 5 cv funcionando com os combust?veis supracitados. Ao final de 150 horas de ensaio de cada combust?vel, o motor foi desmontado, inspecionado visualmente e feito um recondicionamento completo (incluindo bico injetor). O material particulado resultante da combust?o foi coletado por uma c?psula de coleta de gases da combust?o, desenvolvido pelo Grupo de Estudos de Tribologia e Integridade Estrutural (GET/UFRN). T?cnicas de an?lises por microscopia eletr?nica de varredura (MEV) e espectroscopia por energia dispersiva (EDS) foram usadas para avaliar os danos resultantes nos materiais submetidos ? atomiza??o e aos materiais particulados resultantes da combust?o do motor diesel BD 5.0 ap?s 20 e 150 horas. Para cada fluido ensaiado foi utilizado um bico injetor novo e os jatos atomizados por cada bico (novo e ap?s ensaios) foram filmados com c?mera CCD (resolu??o de 10 kfps). Posteriormente esses bicos foram analisados por MEV e EDS. Observaram-se part?culas met?licas com ?reas entre 0,5 e 50,0 ?m2. Evid?ncias de desgaste por ader?ncia, ades?o, corros?o, eros?o e cavita??o foram observadas no bico injetor, devido ao processo de atomiza??o dos fluidos. / A nozzle is a very important component of a diesel engine injection system. It is responsible for the atomization of the fuel for efficient combustion and low pollutant emissions levels, which directly affects the environment and the human cardiovascular system. The standards of vehicle emissions set by the environmental legislation are increasingly stringent, as PROCONVE P7 in Brazil and Euro 6, in the European Union. They restrict the size of the particulate material and NOx emissions levels. The main objective of this thesis is to investigate and understand the wear mechanisms of brittle and ductile materials which undergo the action of an atomizer type common rail, erosion, cavitation, adherence, adhesion, and corrosion. A systematic method was developed for evaluating diesel biofuels with additives or obtained in gas stations, its process of atomization and its interaction with two structural materials: a chemically active, electrolytic copper, and a chemically inert, silicon oxide glass. A test rig equipped with a high-pressure atomizing chamber (HPSC), a carrier device for ductile and brittle materials and a CCD camera were used to evaluate the atomization process. In this test rig there were tested three fluids: Ultrasene (standard fluid of the fluid nozzle testing machine TM 507), B6, B6 additivated with surfactants plus water and additivated B6 with surfactants, water and glycerin. A dynamometer test rig was used for testing a stationary diesel single cylinder engine, brand Branco, model BD5.0, four-stroke, 5 cv diesel, with the aforementioned fuels. In the end of 150 hours of each test fuel, the engine was disassembled, visually inspected and its main parts were replaced - piston, piston rings, pin, connecting rod, bearings, valves, seals, gaskets and the nozzle repair were replaced. The particulate matter coming from the combustion process, was collected by a device developed in the Tribology Study Group and Structural Integrity (GET-UFRN). Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) techniques were used to assess the damage resulting from the materials submitted to atomization and the particulate matter from the exhaust of combustion after 20 and 150 hours. Each fluid was atomized by a new nozzle and the spray atomized by each nozzle (the new one and after testing) was recorded using a CCD camera in a 10 kfps resolution. Posteriorly, those nozzles were analyzed by SEM and EDS. It was observed metal particles ranging in size from 0.5 to 50.0 ?m2. Evidences of wear by adherence, adhesion, corrosion, erosion and cavitation were observed on inject nozzle because the fuel atomization processes.
8

Crescimento econ?mico e emiss?es de CO2 nos pa?ses do BRICS: uma an?lise de cointegra??o em painel

Castro, Alisson Silva de 03 March 2017 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-06-02T22:11:01Z No. of bitstreams: 1 AlissonSilvaDeCastro_DISSERT.pdf: 1319465 bytes, checksum: 4477f75a156b9042925aa89689666c02 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-06-07T23:35:12Z (GMT) No. of bitstreams: 1 AlissonSilvaDeCastro_DISSERT.pdf: 1319465 bytes, checksum: 4477f75a156b9042925aa89689666c02 (MD5) / Made available in DSpace on 2017-06-07T23:35:12Z (GMT). No. of bitstreams: 1 AlissonSilvaDeCastro_DISSERT.pdf: 1319465 bytes, checksum: 4477f75a156b9042925aa89689666c02 (MD5) Previous issue date: 2017-03-03 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Nos ?ltimos anos, a eleva??o cont?nua no volume de emiss?es de di?xido de carbono (CO2) e sua concentra??o na atmosfera colocou o tema da mudan?a clim?tica no centro do debate pol?tico-econ?mico mundial. Atualmente, os maiores emissores de CO2 do mundo s?o os pa?ses emergentes, denominado BRICS, que v?m apresentando um crescimento econ?mico expressivo e respondendo por mais de 40% das emiss?es totais deste poluente no planeta (EIA, 2016). Em termos anal?ticos, o estudo da rela??o entre crescimento econ?mico e emiss?es de poluentes t?m sido feito com base na abordagem da Curva de Kuznets Ambiental (CKA), a qual implica a exist?ncia de uma rela??o no formato de um ?U? invertido entre polui??o e renda. Desta forma, ? medida que a renda alcan?a um determinado patamar as emiss?es de poluentes come?am a declinar, fazendo com que haja uma melhora na qualidade ambiental. Neste sentido, o objetivo geral desta pesquisa foi o de verificar se existe uma CKA para o grupo de pa?ses do BRICS utilizando a metodologia econom?trica de cointegra??o em dados em painel. Al?m da vari?vel PIB per capita, foram adicionadas mais tr?s vari?veis ao modelo: consumo per capita de energia, fluxo de com?rcio e uma dummy para captar os efeitos do Protocolo de Quioto sobre o n?vel de emiss?es destes pa?ses. Os resultados do modelo econom?trico indicaram a exist?ncia de uma rela??o no formato de um ?U? invertido entre renda per capita e emiss?es de CO2, com pontos de inflex?es de US$ 2.033,89 e US$ 2.057,61 respectivamente, nos estimadores FMOLS e DOLS. O consumo per capita de energia apresentou uma rela??o positiva com as emiss?es de CO2, enquanto a rela??o da vari?vel de com?rcio internacional foi negativa. Al?m disso, o coeficiente da vari?vel dummy n?o apresentou signific?ncia estat?stica. Assim, julga-se necess?rio a implementa??o de pol?ticas ambientais nos pa?ses do BRICS que estimulem o crescimento econ?mico com aumento da participa??o de fontes renov?veis, melhor efici?ncia energ?tica e transa??es comerciais que envolvam a transfer?ncia de tecnologia menos poluente para estes pa?ses. Ademais, acredita-se que um Acordo internacional de redu??o das emiss?es de CO2 que recaia tamb?m sobre os pa?ses em desenvolvimento ? de extrema relev?ncia para diminuir o n?vel de emiss?es e manter a temperatura do planeta em patamar est?vel. / In recent years, a steady rise in carbon dioxide (CO2) emissions and its own concentration on the atmosphere put the climate change issue at the center of the global political-economic debate. Today, the world's largest emitters of CO2 are the emerging BRICS countries, which show significant economic growth and account for more than 40% of total emissions of this pollutant on the planet (EIA, 2016). In analytical terms, the study of the relationship between economic growth and pollutant emissions has been made based on the Environmental Kuznets Curve (CKA) approach, which implies an shaped relationship of an inverted "U" between pollution and Income In this way, as income reaches a certain level the emissions of pollutants begin to decline, resulting an improvement in environmental quality. In this sense, the general objective of the research is to verify if there is an evidence of CKA hypothesis for the BRICS group of countries using an economic methodology of panel data cointegration. In addition to the GDP per capita variable, three more variables were added to the model: per capita energy consumption, trade flow and a dummy to capture the effects of the Kyoto Protocol on countries' emissions levels. The results of the econometric model indicated an existence of a relationship of an inverted "U" between per capita income and CO2 emissions, with inflection points of US $ 2,033.89 and US $ 2,057.61, respectively, in the FMOLS and DOLS. The per capita consumption of energy showed a positive relation with CO2 emissions, while a relation of the international trade variable was negative. In addition, the coefficient of the dummy variable, which measures the effects of the Kyoto Protocol, was not statistically significant. Thus, it is considered necessary to implement environmental policies in BRICS countries that stimulate economic growth by increasing the share of renewable sources, better energy and transactions that imply a transfer of less polluting technology to these countries. In addition, it is believed that an international agreement to reduce CO2 emissions that also includes developing countries is extremely important to reduce the level of emissions and keep the planet's temperature at a stable level.
9

Avalia??o da flamabilidade e dos res?duos de queima de tintas acr?licas ? base d'?gua

Henrique, Angelo Abel Machado Pereira 29 September 2017 (has links)
Submitted by PPG Engenharia e Tecnologia de Materiais (engenharia.pg.materiais@pucrs.br) on 2018-06-04T14:42:13Z No. of bitstreams: 1 DISSERTA??O FINAL - ANGELO ABEL.pdf: 2908441 bytes, checksum: 7b4f57513c25b05da3fbcc36003b7939 (MD5) / Approved for entry into archive by Sheila Dias (sheila.dias@pucrs.br) on 2018-06-11T14:34:47Z (GMT) No. of bitstreams: 1 DISSERTA??O FINAL - ANGELO ABEL.pdf: 2908441 bytes, checksum: 7b4f57513c25b05da3fbcc36003b7939 (MD5) / Made available in DSpace on 2018-06-11T14:46:48Z (GMT). No. of bitstreams: 1 DISSERTA??O FINAL - ANGELO ABEL.pdf: 2908441 bytes, checksum: 7b4f57513c25b05da3fbcc36003b7939 (MD5) Previous issue date: 2017-09-29 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / In this work, the sample-flame propagation indexes were simulated in laboratory, in detriment and in comparison to the generalized burning during the fires in internal environments. The respective chemical and physical properties of the paints, the emanated gases, were compared; evidencing its toxicities, toxicological thresholds and using the tests of horizontal burning and vertical burning. In the experimental part, the paint films were produced for later burning in a quartz chamber with the use of the electric furnace, from which the gases were collected, according to each thermal degradation orientation obtained by the TGA pallet, in order to analyze the toxicities in gas chromatography. In the results the different firing behaviors for each paint can be compared by virtue of its physico-chemical composition, together with its gas release rates in each temperature range. / Neste trabalho produziu-se a partir das tintas acr?licas ? base d??gua, os ?ndices de propaga??o de chama amostral e simulada em laborat?rio, em detrimento e em comparativo ? queima generalizada durante os inc?ndios em ambientes internos. Foram comparadas as respectivas propriedades qu?micas e f?sicas das tintas, dos gases emanados; evidenciando as suas toxicidades, limiares toxicol?gicos e empregando os testes de queima horizontal e queima vertical. Na parte experimental foram produzidos os filmes de tintas, para posterior queima em c?mara de quartzo com o uso do forno el?trico, onde a partir deste, coletou-se os gases, segundo cada orienta??o de degrada??o t?rmica obtida pala TGA, para ent?o serem analisadas as toxicidades em cromatografia gasosa. Nos resultados podem ser comparados os diferentes comportamentos de queima para cada tinta em virtude de sua composi??o f?sico-qu?mica, juntamente com suas taxas de libera??es de gases em cada faixa de temperatura.
10

Aproveitamento energ?tico de finos de carv?o em alto forno, visando redu??o de emiss?es e obten??o de cr?ditos de carbono. / The use of fines of coal as fuel in blast furnaces, aiming the reduction of emissions and the acquisition of carbon credits.

Machado, Flavio Silva 27 November 2009 (has links)
Made available in DSpace on 2016-04-28T14:56:37Z (GMT). No. of bitstreams: 1 2009 - Flavio Silva Machado.pdf: 1243667 bytes, checksum: a4dcd3f6ca4e213e694088f27e855547 (MD5) Previous issue date: 2009-11-27 / The main aim of this paper is to check the environmental and economical gains of mixtures of fines of vegetal and mineral coal (both Brazilian and imported ones) in the injection in blast furnaces for iron, aiming its use as fuel, the lowering of carbon emission rates, the trading of Reduced Emission Certificates and also restart the production of Brazilian mineral coal for the steel making industry. It was used vegetal coal from Eucalyptus urophylla woods (CVSG). The mineral coal was from Australia and Indonesia (S.Walker Creek Weak and Kaltim Prima coals) and the Brazilian mineral coals from the several coal mines located in the south of Brazil, such as: coal CRM-CE4200 (CN1), coal CRM-CE6700 (CN2), coal COPELMICE5200 (CN3), coal COPELMI-CE6000 (CN4), coal COPELMI-CE6500 (CN5), Carbon?fera Metropolitana-Antracito-CM20 (CN6) and Rio Deserto mineral coal (CN7). The results of elementary and immediate chemical analyses were evaluated as well as the analyses of coal ash components, the binary basicity of scraps, the size of grains, the grindability and the density and porosity of the coals. Vegetal coal fines were mixed to mineral coal fines from abroad and from Brazil in different proportions and the main characteristics of each mix were evaluated; such characteristics are important when the injection in blast furnaces is made. (operational limits). It was also evaluated the efficiency in burning of each coal mix. Having the combustion efficiency rates as base, the 80% mix CVSG 20% CN1 presented the best conditions to be injected in the blast furnace tuyeres. This mix also presented favorable environmental conditions because it allowed the lowering of carbon emission rates, as much as 41,26 kilos per ton of produced pig iron. Such rates improved the trading of Reduced Emission Certificates to US$ 0.86/ton of produced iron. Moreover, there was a reduction in the injection of coal fines of US$ 1.20/ton of iron. Adding up environmental and economical gains, using the 80 % CVSG 20 % CN1 mix, the amount of US$ 2.06/ton of iron is reached. / O objetivo geral deste trabalho foi avaliar os ganhos ambientais e econ?micos, de misturas de finos carv?o vegetal com carv?o mineral (importado e nacional), atrav?s da inje??o em alto forno, visando o aproveitamento de matriz energ?tica, a redu??o dos ?ndices de emiss?es de carbono, a comercializa??o de Certificados de Emiss?es Reduzidas e tamb?m a retomada da produ??o de carv?o mineral nacional para o setor sider?rgico. Foram utilizados carv?o vegetal proveniente da madeira de Eucalytus urophylla (CVSG), carv?es minerais importados da Austr?lia e Indon?sia (carv?o S. Walker Creek Weak e carv?o Kaltim Prima) e carv?es minerais nacionais provenientes de diferentes minas localizadas na Regi?o Sul do Brasil, a saber: carv?o CRM-CE4200 (CN1), carv?o CRM-CE6700 (CN2), carv?o COPELMI-CE5200 (CN3), carv?o COPELMI-CE6000 (CN4), carv?o COPELMI-CE6500 (CN5), Carbon?fera Metropolitana-Antracito-CM20 (CN6) e Carv?o mineral Rio Deserto CN7). Foram avaliados os resultados das an?lises qu?micas imediata e elementar, bem como da composi??o das cinzas dos carv?es; da basicidade bin?ria das esc?rias; da granulometria, da moabilidade, da densidade e da porosidade dos carv?es. Finos de carv?es vegetais foram misturados com finos de carv?o mineral importado e nacional em diferentes propor??es, sendo avaliadas as principais caracter?sticas das misturas que s?o importantes quando se procede a inje??o no alto forno sider?rgico (limites operacionais). Para cada mistura foi avaliada tamb?m as efici?ncias de queima dos carv?es. Tendo-se por base os ?ndices de efici?ncia de combust?o das misturas de carv?es, a mistura 80 % CVSG 20 % CN1 apresentou melhores condi??es para ser injetada nas ventaneiras do alto forno. Apresentou tamb?m condi??es ambientais favor?veis, pois permitiu redu??o dos ?ndices de emiss?es de carbono na ordem de 41,26 kg por tonelada de ferro gusa produzido e favorecendo a comercializa??o dos Certificados de Emiss?es Reduzidas em US$ 0,86 por tonelada de ferro produzido. Houve tamb?m uma redu??o do custo de inje??o de finos de carv?o de US$ 1,20 por tonelada de ferro produzido. Somando os ganhos ambientais e comerciais com a mistura 80 % CVSG 20 % CN1 ser?o US$ 2,06 por tonelada de ferro produzido.

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