Made available in DSpace on 2015-04-14T13:58:25Z (GMT). No. of bitstreams: 1 398972.pdf: 1270520 bytes, checksum: c981dc4ef6d67b9a25e1efbb0fef41df (MD5) Previous issue date: 2008-01-15 / Este trabalho apresenta um estudo comparativo entre sistemas catal?ticos para a rea??o de transesterifica??o dos ?leos de farelo de arroz. A transesterifica??o do ?leo do farelo de arroz refinado com metanol foi avaliada na presen?a de acido sulf?rico (H2SO4) e compostos de estanho como: cloreto de estanho (SnCl2. 2H2O), 2-etilhexanoato de estanho (Sn(C8H15O2)2), conhecido comercialmente como DBTDL. Os produtos das rea??es foram caracterizados atrav?s da analise comparativa entre os catalisadores, verificou-se uma melhor performance para o DBTDL, com rendimento de 99,9% , no tempo de 4h e rela??es molares de 480:100:5 entre ?lcool, ?leo e catalisador, respectivamente . Estes resultados demonstram a viabilidade do uso de compostos met?licos como catalisadores na obten??o de biodiesel, uma alternativa interessante a catalise acida e b?sica. Nas otimiza??es do processo, foram avaliadas alcoolizes com metanol e etanol, as razoes molares foram variadas e foram utilizados como ?leo de partida, alem dos ?leos refinados, tamb?m ?leos degomados e brutos.

Made available in DSpace on 2015-04-14T13:58:45Z (GMT). No. of bitstreams: 1 436188.pdf: 5507987 bytes, checksum: bb7dbc2c844572b613d5bebdeb70d2ae (MD5) Previous issue date: 2011-08-18 / Since the biodiesel national programs began, many research groups have been studied this fuel efficiency, such as economical aspects, environments effects and engine performance and durability. The research objective was project and build a pin-on-disk device test per ASTM G99 95a (Standard Test Method for Wear Testing with a Pin-on-Disk Apparatus) to test material wear under diesel (B5) biodiesel (B100). The project validation was realized by performing aluminum-silicon wear test under two conditions: in presence of diesel (B5) and in presence of biodiesel (B100), with fix speed of 220 rpm, pin load of 5 N and 8 N during 150,000 cycles. The test analysis desired to compare the wear of an alloy used in diesel engines under different solutions. After the wear test, the disc weight loss, the topography and the microstructure were analyzed. The qualitative preliminary result shows better lubricates of biodiesel (B100) to test conditions adopted. / Desde o surgimento dos programas nacionais para a adi??o de biodiesel no diesel, diversos grupos t?m estudado a efic?cia deste combust?vel, abordando aspectos econ?micos, de meio ambiente, desempenho e durabilidade dos motores diesel. O presente trabalho tem o objetivo de projetar, construir e testar um trib?metro para an?lise de materiais submersos em biodiesel e diesel. O equipamento de teste foi desenvolvido tendo como refer?ncia a norma ASTM G99 95a (Standard Test Method for Wear Testing with a Pin-on-Disk Apparatus). A valida??o do projeto se realizou mediante ensaios de desgaste da liga alum?niosil?cio AA305 em duas condi??es: na presen?a de diesel (B5) e na presen?a de biodiesel (B100), com rota??o fixa de 220 rpm, e for?as de 5 N e 8 N durante per?odos de 150.000 ciclos. As an?lises dos dados tiveram como finalidade fazer um comparativo do desgaste da liga em estudo, utilizada em motores diesel, em diferentes solu??es. Ap?s os ensaios foram analisadas as perdas de massa, a topografia do disco e a microestrutura. A an?lise qualitativa das amostras indicou melhor lubricidade do biodiesel (B100) para as condi??es de teste adotadas.

Submitted by Kelson Anthony de Menezes (kelson@ucb.br) on 2016-11-23T12:14:00Z No. of bitstreams: 1 JessicaCarvalhoBergmannTeseparcial2013.pdf: 124515 bytes, checksum: 0d2877a5336a887b74ef27ed08081d9a (MD5) / Made available in DSpace on 2016-11-23T12:14:00Z (GMT). No. of bitstreams: 1 JessicaCarvalhoBergmannTeseparcial2013.pdf: 124515 bytes, checksum: 0d2877a5336a887b74ef27ed08081d9a (MD5) Previous issue date: 2013-10-07 / The necessity to be a self-suficient producer of fuels is stimulating research for alternative types of energy. Brazil, as well as other countries, is investing in this sector and in 2012 was the second largest biofuel producer in the world. Bioethanol production can double productivity with second generation technology in which bioethanol is produced from cellulose. Biodiesel production from oils using different feedstocks can also contribute for this independency in biofuels production, both locally and globally. This doctorate thesis is divided in two chapters, both attempting to make a contribution to the development of the biofuels sector in Brazil. The first chapter focuses on enzyme discovery for ethanol production from cellulose. The second chapter focuses on the characterization of the soil microbiota associated with oil palm plants with fatal yellowing, which has hindered the development of a biodiesel industry based on palm oil. The first chapter describes prospection for hydrolytic enzymes to be used for biomass deconstruction in second generation bioethanol production. Enzymes were screened from an Amazon soil large insert metagenomic library (30-50 kb). The library containing approximately 213,000 clones was functionally screened, and 15 clones with cellulolytic activity and 16 clones resistant to hydroquinone were identified. The sequences of these 31 clones and an additional 65 other random clones were obtained and analysed using the IMG/MER pipeline. In silico analysis identified several coding regions (CDS) that were amplified by PCR and cloned in expression vectors. The sequences for two beta-glucosidases enzymes, BGL17 and BGL18, were codon optimized before being expressed and purified. Characterization of both enzymes showed that the optimum temperature for BGL17 and BGL18 was 45oC and 40oC, respectively. The optimum pH for BGL17 and BGL18 was 6.0 and for 6.5, respectively. Half-life stability was approximately one hour for both enzymes. Regarding enzyme kinetics, BGL18 showed higher Vmax and Km (11 U/mg ?? 0.0011 and 0.36 mM ?? 0.01612) when compared to BGL17 (85 U/mg ?? 0.0028 and 0.30 mM ?? 0.017). Kcat was only calculated for BGL17 as 38.57 s-1 ?? 0.37 as the purification of BGL18 was not successfull. Chapter two aimed to study the soil bacterial diversity from oil palm trees affected by fatal yellowing disease (bud rot) in three different stages. The strategy used was pyrosequencing of the gene for the 16S ribosomal RNA (16S rRNA). Oil palm is an oilcrop produced in the north region of Brazil with hight oil yield, which makes it a good candidate for biodiesel production. However, oil palm trees are being affected by fatal yellowing (FY) for more than 20 years, but to this date no etiological agent was identified. Observation was reported where healthy palm tree were planted in the same spot as previously sick tree, developed FY after a period of time, suggesting that the disease could be transmitted by some microorganism in the soil. In this work, the gene for 16S rRNA was amplified from DNA extracted from soil of diseased oil palm trees (stages 5 and 8) and from plants with no symptoms of the disease and sequenced. Pyrosequencing originated 839,694 sequences. After artifacts and chimeras were removed, 498,397 sequences distributed in 9 samples (3 for each disease stage) remained to be analyzed. Sequences were analyzed using the Qiime pipeline (Quantitative Insights in Microbial Ecology) and taxonomic classification of sequences was obtained based on the RDP (Ribossomal Database Project). The most abundant phyla in the samples were Acidobacteria, Proteobacteria, Planctomycetes, Firmicutes and Verrucomicrobia. Alpha and Beta diversity were calculated and taxonomic comparisons were performed by STAMP software. Results showed that the bacterial communtiy associated with soils of diseaded plants on stage 5 (DCA5) and stage 8 had a higher number of observed OTUs than stage 0, as determined by the Chao1 phylogenetic diversity index. Beta-diversity analysis showed that the different biological replicates of soil from diseased plants of the same stage are significantly different, as shown in PCoA (Principal Coordenate Analysis). Taxonomic comparison showed more rare phyla associated to stages 5 and 8 of the disease. This work is the first to study the bacterial microbiota associated with soils of oil palm plants with and without symptoms of fatal yellowing with next generation sequencing. / A necessidade de produzir combust??veis para que futuramente haja independ??ncia na produ????o de energia, vem impulsionando pesquisas no setor de energias alternativas. O Brasil, assim como outros pa??ses emergentes, tem investido e ganhado espa??o neste cen??rio, sendo hoje o segundo maior produtor mundial de biocombust??veis. A produ????o de bioetanol, apesar de j?? bem estabelecida no pa??s, poder?? dobrar com a tecnologia de produ????o de etanol de segunda gera????o (a partir da biomassa). Al??m disso, com a produ????o de biodiesel a partir do ??leo de diferentes culturas oleaginosas poder?? contribuir para esta independ??ncia na produ????o de biocombust??veis localmente e globalmente. Esta tese est?? dividida em dois cap??tulos, ambos tratando como produto final a produ????o de biocombust??veis. O cap??tulo um teve como objetivo a prospec????o de enzimas hidrol??ticas para serem utilizadas durante o processo de hidr??lise enzim??tica e clones resistentes a produtos secund??rios formados durante o processo de pr??-tratamento na produ????o de etanol de segunda gera????o. Construiu-se uma biblioteca metagen??mica de grandes insertos (30-50 kb) em fosm??deo a partir de DNA da comunidade microbiana do solo amaz??nico. A biblioteca contendo aproximadamente 213.000 clones foi triada funcionalmente, identificando 15 clones com atividade celulol??tica e 16 clones resistentes ?? hidroquinona (produto t??xico a leveduras produzido durante o pr??tratamento). Estes 31 clones com atividade na triagem funcional, somados a outros 65 clones selecionados aleatoriamente, foram sequ??nciados e suas sequ??ncias depositadas no pipeline IMG/MER (JGI) onde foram anotadas. A an??lise computacional dos clones com atividades enzim??ticas permitiu a identifica????o de diferentes regi??es codificantes (CDs) que foram amplificadas por PCR e clonadas em vetores de express??o. Conseguiu-se a express??o de duas enzimas beta-glicosidases (BGL17 e BGL18) que tiveram suas sequ??ncias otimizadas antes de serem purificadas. A caracteriza????o destas enzimas mostrou que a BGL17 e BGL18 possuem uma temperatura ??tima de 45oC e 40oC, respectivamente, e um pH ??timo de 6 e 6,5, respectivamente, com estabilidade m??dia nestas condi????es em torno de uma hora. A BGL17 possui um valor de Vmax e Km de 85 U/mg e 0,30 mM ?? 0.017 enquanto a BGL18 possui os valores de Vmax e Km de 11,01 U/mg e 0,36 mM ?? 0,01612. O cap??tulo dois visou o estudo da microbiota de solo de dendezeiros acometidos pelo amarelecimento fatal (AF) em diferentes est??gios da doen??a utilizando como estrat??gia o pirosequenciamento do gene para 16S rRNA. A planta do dend?? ?? uma oleaginosa produzida principalmente no norte do Brasil e possui um alto rendimento de ??leo o que a torna uma boa candidata a produ????o de biodiesel. Por??m, o dendezeiros t??m sido acometidos pelo AF, sendo seu agente etiol??gico procurado h?? mais de 20 anos sem resultados conclusivos. Plantas sadias que foram replantadas no mesmo lugar de plantas doentes desenvolveram a doen??a, criando-se a hip??tese da transmiss??o do AF ocorrer pelo solo. Neste trabalho, realizou-se o pirosequenciamento do gene para 16S rRNA amplificado da comunidade bacteriana de uma amostra de solo da base de dendezeiros acometidos por AF em dois est??gios da doen??a (est??gio 5 e est??gio 8) e aparentemente sem doen??a (est??gio 0). O sequenciamento gerou 839.694 sequ??ncias que depois de retirados os artefatos totalizaram 498.397 sequ??ncias distribu??das em 9 pontos (3 para cada est??gio da doen??a). As sequ??ncias foram analisadas utilizando-se o programa Qiime (Quantitative Insights in Microbial Ecology) e sua classifica????o taxon??mica atribu??da de acordo com o RDP-II (Ribossomal Database Project). Os filos mais abundantes encontrados foram Acidobacteria, Proteobacteria, Planctomycetes, Firmicutes e Verrucomicrobia. An??lises de alfa e beta diversidade foram realizadas e compara????es taxon??micas foram feitas utilizando o programa STAMP (Statistical Analysis of Metagenomic Profiles). Os resultados mostraram que os pontos DCA5 (dendezeiros com AF no est??gio 5 da doen??a) apresentam maior quantidade de OTUs observadas em rela????o a diversidade filogen??tica e ??ndice de Chao1. As an??lises de beta-diversidade mostraram que os agrupamentos entre os pontos por sintomas da doen??a s??o significativamente diferentes. Compara????es taxon??micas mostraram uma maior presen??a de filos raros nos est??gios 5 e 8. Este trabalho foi o primeiro realizado tentando elucidar o causador do AF utilizando sequenciamento de ??ltima gera????o. Estes resultados ir??o contribuir para futuros estudos do Amarelecimento Fatal.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2015-12-04T20:21:19Z No. of bitstreams: 1 RayanaHozanaBezerril_TESE.pdf: 1462425 bytes, checksum: cac67c7bf1570bf9fe04615be96e17d0 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2015-12-09T23:46:58Z (GMT) No. of bitstreams: 1 RayanaHozanaBezerril_TESE.pdf: 1462425 bytes, checksum: cac67c7bf1570bf9fe04615be96e17d0 (MD5) / Made available in DSpace on 2015-12-09T23:46:58Z (GMT). No. of bitstreams: 1 RayanaHozanaBezerril_TESE.pdf: 1462425 bytes, checksum: cac67c7bf1570bf9fe04615be96e17d0 (MD5) Previous issue date: 2014-07-25 / Dentre as atividades econ?micas potencialmente poluidoras que comprometem a qualidade do solo e da ?gua subterr?nea est?o os postos revendedores de combust?veis. O vazamento de combust?veis derivados do petr?leo a partir de tanques subterr?neos ou atividades realizadas indevidamente com estes poluentes podem contaminar extensas ?reas, causando s?rios problemas ambientais e toxicol?gicos. O n?mero de postos de combust?veis cresceu desordenadamente, sem nenhum tipo de controle, com isso os impactos ambientais gerados por esses empreendimentos cresceram ocasionando a polui??o do solo e da ?gua subterr?nea. V?rias t?cnicas utilizando tensoativos t?m sido propostas para remedia??o deste tipo de contamina??o. Este estudo apresenta como inova??o a aplica??o de diferentes sistemas contendo tensoativos na fase vapor e compara suas efici?ncias de remo??o de diesel de um solo contendo esse contaminante. Para isso, foi utilizado um sistema que cont?m sete po?os injetores das seguintes solu??es vaporizadas : ?gua, solu??es de tensoativo, microemuls?o e nanoemuls?o, Os tensoativos utilizados foram o ?leo de Coco Saponificado (OCS), em solu??o aquosa e um ?lcool etoxilado UNTL-90: em solu??o aquosa, e em sistemas de microemuls?o e nanoemuls?o. Dentre os sistemas investigados, a nanoemuls?o foi a que apresentou maior efici?ncia de remo??o com 88% do diesel, sendo a mais vi?vel ecol?gica e tecnicamente por ser um sistema com menor teor de mat?ria ativa. / Among the potentially polluting economic activities that compromise the quality of soil and groundwater stations are fuel dealers. Leakage of oil derived fuels in underground tanks or activities improperly with these pollutants can contaminate large areas, causing serious environmental and toxicological problems. The number of gas stations grew haphazardly, without any kind of control, thus the environmental impacts generated by these enterprises grew causing pollution of soil and groundwater. Surfactants using various techniques have been proposed to remedy this kind of contamination. This study presents innovation as the application of different systems containing surfactant in the vapor phase and compares their diesel removal efficiencies of soil containing this contaminant. For this, a system that contains seven injection wells the following vaporized solutions: water, surfactant solution, microemulsion and nanoemulsion, The surfactants used were saponified coconut oil (OCS), in aqueous solution and an ethoxylated alcohol UNTL-90: aqueous solution , and nanoemulsion and microemulsion systems. Among the systems investigated, the nanoemulsion showed the highest efficiency, achieving 88% removal of residual phase diesel, the most ecologically and technically feasible by a system with lower content of active matter

Made available in DSpace on 2014-12-17T14:58:13Z (GMT). No. of bitstreams: 1 JoseCTN_DISSERT.pdf: 3330335 bytes, checksum: 998a47f5aaa9275ec35cf7e52cf1d08e (MD5) Previous issue date: 2012-03-16 / This work presents the analysis of data collected by Universidade Federal do Rio Grande do Norte and State Public Prosecution Office experts concerning to current situation of liquid fuel resale stations, its forms of storage and its technical apparatus for the performance of primary functions (supply of vehicles) and secondary (car washing, storage of used oil, oil change etc.). The data presented were analyzed in the setting of the city of Natal (RN) and considering its characteristics, potentialities and weaknesses. Thereafter, it was discussed liquid fuels resale pollution potential in the city and legal provisions directed to implementation of Green Seal. The discussion involves three agents: environmental, legal and technical ones, applied to all 110 resale fuel stations which were analyzed / Este trabalho apresenta a an?lise dos dados colhidos pelos peritos da Universidade Federal do Rio Grande do Norte e do Minist?rio P?blico Estadual referentes ? situa??o dos postos de revenda de combust?veis l?quidos, suas formas de armazenamento e o seu aparato t?cnico para o exerc?cio das fun??es principal (abastecimento de ve?culos) e secund?ria (lavagem de ve?culos, armazenamento de ?leo usado, troca de ?leo etc.). Os dados apresentados foram analisados sob a configura??o da Cidade de Natal (RN) e levando-se em considera??o suas caracter?sticas, potencialidades e fragilidades. Da? por diante, discutiu-se sobre o potencial poluidor da atividade de revenda de combust?veis l?quidos na cidade e as disposi??es legais direcionadas para a implanta??o do Selo Verde. A discuss?o apresentada envolve principalmente tr?s agentes: o ambiental, o legal e o t?cnico, aplicados aos 110 postos de revenda de combust?veis analisados

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-03-20T20:04:27Z No. of bitstreams: 1 ThiagoDaSilvaAndre_DISSERT.pdf: 3053224 bytes, checksum: bd505205f3c547b71bf4aef350ec5642 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-03-22T21:27:33Z (GMT) No. of bitstreams: 1 ThiagoDaSilvaAndre_DISSERT.pdf: 3053224 bytes, checksum: bd505205f3c547b71bf4aef350ec5642 (MD5) / Made available in DSpace on 2017-03-22T21:27:33Z (GMT). No. of bitstreams: 1 ThiagoDaSilvaAndre_DISSERT.pdf: 3053224 bytes, checksum: bd505205f3c547b71bf4aef350ec5642 (MD5) Previous issue date: 2016-12-19 / Este trabalho ? resultado de um estudo de an?lises experimentais que mediram a taxa de evapora??o, em fun??o da temperatura, de quatro combust?veis, a saber: gasolina comum, ?lcool combust?vel, Diesel S10 e gasolina GRID, realizados para seis n?veis t?rmicos diferentes, seguido de uma an?lise de custos das perdas potenciais por evapora??o, aplicada a tanques subterr?neos de postos de combust?veis. Quando esses combust?veis liberam vapores ? atmosfera podem causar danos ao meio ambiente. Em postos de servi?os, esse vapor ? liberado quando do abastecimento do ve?culo ou pelas linhas de respiro do Sistema de Abastecimento Subterr?neo de Combust?veis - SASC. Quando o posto n?o possui prote??es contra essas emiss?es fugitivas, elas atingem flora, rios, len??is fre?ticos etc. Al?m da polui??o dos recursos naturais, a perda por evapora??o atinge as finan?as do posto de combust?vel, tanto pelas multas geradas pelas contamina??es, quanto pela perda de ativo, os combust?veis. Dos combust?veis avaliados, o que apresentou a maior taxa de evapora??o foi a gasolina GRID, seguido da gasolina comum, ?lcool e diesel S10. / This work is the result of a study of experimental tests that measured the rate of evaporation, temperature, of four fuels, namely: ordinary gasoline, ethanol fuel, Diesel and gas GRID, S10 for six different heat levels, followed by a cost analysis of the potential losses for evaporation, applied to underground tanks of gas stations. When these fuels release vapors into the atmosphere can cause damage to the environment. In service stations, this vapor is released when the supply of the vehicle or the vent lines of Underground fuel supply system-SASC. When the gas station does not have protections against these fugitive emissions, they reach flora, rivers, groundwater etc. Apart from the problem of pollution of natural resources, the loss by evaporation reaches the finances of the gas station, both by the fines generated by the contamination, and the loss of active, fuel. Of fuels evaluated presented the highest evaporation rate was the gas GRID, followed by ordinary gasoline, alcohol and diesel S10.

Made available in DSpace on 2014-12-17T14:06:58Z (GMT). No. of bitstreams: 1 WalquiriaJS_DISSERT_PACIAL.pdf: 740304 bytes, checksum: 3d1d601a3873230ed2af2ce67496fdf5 (MD5) Previous issue date: 2011-07-21 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The development and study of detectors sensitive to flammable combustible and toxic gases at low cost is a crucial technology challenge to enable marketable versions to the market in general. Solid state sensors are attractive for commercial purposes by the strength and lifetime, because it isn t consumed in the reaction with the gas. In parallel, the use of synthesis techniques more viable for the applicability on an industrial scale are more attractive to produce commercial products. In this context ceramics with spinel structure were obtained by microwave-assisted combustion for application to flammable fuel gas detectors. Additionally, alternatives organic-reducers were employed to study the influence of those in the synthesis process and the differences in performance and properties of the powders obtained. The organic- reducers were characterized by Thermogravimetry (TG) and Derivative Thermogravimetry (DTG). After synthesis, the samples were heat treated and characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), analysis by specific area by BET Method and Scanning Electron Microscopy (SEM). Quantification of phases and structural parameters were carried through Rietveld method. The methodology was effective to obtain Ni-Mn mixed oxides. The fuels influenced in obtaining spinel phase and morphology of the samples, however samples calcined at 950 ?C there is just the spinel phase in the material regardless of the organic-reducer. Therefore, differences in performance are expected in technological applications when sample equal in phase but with different morphologies are tested / O desenvolvimento e estudo de detectores sens?veis a gases combust?veis inflam?veis e t?xicos de baixo custo ? um desafio tecnol?gico determinante para possibilitar vers?es comercializ?veis ao mercado em geral. Sensores no estado s?lido s?o atrativos para fins comerciais pela robustez e tempo de vida, uma vez que n?o s?o consumidos durante o processo de rea??o com o g?s. Paralelamente, o uso de t?cnicas de s?ntese mais vi?veis pela aplicabilidade em escala industrial s?o mais atrativas para obten??o de produtos comerciais. Dentro desse contexto foram obtidos materiais cer?micos com estrutura espin?lio via combust?o assistida por microondas, visando aplica??o em detectores de gases combust?veis inflam?veis. Adicionalmente foram empregados direcionadores-org?nicos alternativos para estudo da influ?ncia dos mesmos no processo de s?ntese e nas diferen?as nas propriedades e desempenho dos p?s obtidos. Os direcionadores-org?nicos foram caracterizados por Termogravimetria (TG). Ap?s a s?ntese, as amostras foram tratadas termicamente e caracterizadas por Espectroscopia de absor??o na regi?o do infravermelho com Transformada de Fourier (FTIR), Difra??o de Raios X (DRX), Medidas de ?rea espec?fica por BET e Microscopia Eletr?nica de Varredura (MEV). A quantifica??o de fases e a determina??o de par?metros estruturais foram determinados por refinamento atrav?s do M?todo Rietveld. A metodologia empregada foi eficaz para obten??o de ?xidos mistos Ni-Mn. Os combust?veis utilizados influenciaram na obten??o da fase espin?lio e na morfologia das amostras, sendo que as amostras calcinadas a 950?C s?o monof?sicas independentemente do direcionador. Logo, diferen?as de desempenho s?o esperadas em aplica??es tecnol?gicas quando amostras iguais em fase mas com diferentes morfologias s?o testadas

Made available in DSpace on 2014-12-17T14:53:18Z (GMT). No. of bitstreams: 1 LucianaTCM_DISSERT.pdf: 2651795 bytes, checksum: 7c2c35dffa683db2b43fb59f0a6f1b0e (MD5) Previous issue date: 2013-12-06 / The customer loyalty became strategy factor for the sustainability of business enterprises. And will be them competitive is important to describe the factors than the consumers consider for to choose the business than will buy the product or service. The dissertation objective is to know the factors that influence the consumer s satisfaction and loyalty in gas stations of Natal/RN, using the index national of customer satisfaction. The literature review was directed for strategy concepts, service quality, satisfaction and fidelity consumer and index national of customer satisfaction. The method used was descriptive-explicative, with application of a survey, from march 15 until april 15 of 2013, with 391 consumers of gas station. In relational analysis, we considered eight constructs: quality, price, complaints, satisfaction, image, loyalty, affection and commitment calculated. For customer satisfaction, the factors that influence have resulted in fuel quality, technical skills of vendors and duration of service. For customer loyalty, the factors that influence resulted in: image, feeling for distributor flag post, location and overall satisfaction with the gas station / A fidelidade dos clientes tornou-se fator estrat?gico para a sustentabilidade do neg?cio das empresas. E para torn?-las competitivas ? importante identificar os fatores que os clientes levam em considera??o para escolher a empresa em que ir?o comprar o produto/servi?o. Esta disserta??o de mestrado objetiva conhecer os fatores que influenciam a satisfa??o e fidelidade dos clientes em postos de combust?veis de Natal/RN, tomando como base o modelo noruegu?s de ?ndice de satisfa??o do consumidor. A pesquisa te?rica foi fundamentada nos conceitos de estrat?gia, qualidade nos servi?os, satisfa??o e fidelidade do cliente e especificamente nos ?ndices nacionais de satisfa??o do cliente. O m?todo utilizado foi descritivo-explicativo, com aplica??o de uma pesquisa do tipo survey, no per?odo de 15 de mar?o ? 15 de abril de 2013, com 391 clientes de postos de combust?veis. Foram considerados na an?lise relacional oito constructos: qualidade, pre?o, reclama??o, satisfa??o, imagem, fidelidade, afetividade e compromisso calculado. Para a satisfa??o dos clientes, os fatores que influenciam resultaram em: qualidade do combust?vel; habilidades t?cnicas dos vendedores e tempo de atendimento. Para a fidelidade do cliente, os fatores que influenciaram resultaram em: imagem, sentimento em rela??o a bandeira distribuidora, localiza??o do posto e satisfa??o geral com o posto

Made available in DSpace on 2014-12-17T14:07:06Z (GMT). No. of bitstreams: 1 RayssaRNMS_DISSERT.pdf: 4171010 bytes, checksum: 0d447597643468751a7d9a8d1824c61d (MD5) Previous issue date: 2012-08-31 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The field of "Materials Chemistry" has been developing in recent years and there has been a great increase of interest in the synthesis and chemical and physical properties of new inorganic solids. New routes of synthesis and synthesis modified has been developed with the aim not only to optimize the processes in laboratory scale, but also on an industrial scale, and make them acceptable by current environmental legislation. The phenomenology of current solid state chemistry properties coupled with the high temperature superconductivity, ferromagnetism, porosity molecular and colors are evidence affected by the synthesis method, which in turn can influence the technological application of these materials. From this understanding, mixed oxides of nickel and zinc nanoparticulate were synthesized by microwave-assisted combustion route using three specific types of organic fuels employing the weight ratios 1:1/2 and 1:1 of cation metallic/fuel, in order to investigate the influence of such proportions to obtain the solids. The new fuels were chosen to replace, for example, urea or glycine that are the fuels most commonly preferred in this kind of synthesis. The powders without heat treatment were studied by Thermogravimetric analysis (TGA), X-Ray Diffraction (XRD) and then calcined at 900?C. After heat treatment, the samples were characterized by analysis of X Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The modified synthesis route porposed was effective for obtaining powders. Both the alternative fuels chosen as the different weight ratios employed, influenced in the morphology and obtaining oxides / O campo da Qu?mica de Materiais vem se desenvolvendo nos ?ltimos anos, tendo havido um grande aumento do interesse na s?ntese e nas propriedades qu?micas e f?sicas de novos s?lidos inorg?nicos. Novas rotas de s?nteses e s?nteses modificadas tem sido desenvolvidas com o intuito n?o apenas de otimizar os processos em escala laboratorial, como tamb?m em escala industrial, al?m de torn?-los aceit?veis pela legisla??o ambiental vigente. A atual fenomelogia da qu?mica do estado s?lido aliada ?s propriedades de supercondutividade ? alta temperatura, ferromagnetismo, porosidade molecular e cores s?o evid?ncias afetadas pelo m?todo de s?ntese, que por sua vez, podem influenciar na aplica??o tecnol?gica desses materiais. Foi a partir desta compreens?o, que ?xidos mistos de n?quel e zinco nanoparticulados foram sintetizados atrav?s da rota combust?o por microondas utilizando tr?s tipos espec?ficos de combust?veis e empregando as raz?es m?ssicas 1:1 e 1:1/2 de c?tions met?licos/combust?vel, com o intuito de averiguar a influ?ncia de tais propor??es na obten??o dos s?lidos. Os novos combust?veis foram escolhidos em substitui??o a ur?ia ou glicina que s?o mais comumente preferidos nesse tipo de s?ntese. Os p?s sem tratamento t?rmico foram estudados atrav?s da An?lise Termogravim?trica (ATG) e da Difra??o de Raios-X (DRX), sendo, em seguida, submetidos ao tratamento t?rmico ? 900?C. Ap?s as calcina??es, foram caracterizados atrav?s das an?lises Difra??o de raiosx (DRX) e Microscopia Eletr?nica de Varredura (MEV). A rota de s?ntese modificada foi eficaz para obten??o dos p?s. Tanto os combust?veis alternativos escolhidos quanto as diferentes raz?es m?ssicas empregadas, influenciaram na morfologia e na obten??o dos ?xidos

Made available in DSpace on 2014-12-17T14:08:52Z (GMT). No. of bitstreams: 1 RaoniBA_DISSERT.pdf: 2283831 bytes, checksum: 9e3bfc1213fc5b5ac439fb175ddc5631 (MD5) Previous issue date: 2012-12-14 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The retail fuel stations are partially or potentially polluters and generators of environmental accidents, potentially causing contamination of underground and surface water bodies, soil and air. Leaks in fuel retail stations? underground storage systems are often detected in Brazil and around the world. Monoaromatic hydrocarbons, BTEX (benzene, toluene, ethylbenzene and xylenes) and polycyclic aromatic hydrocarbons (PAHs) are an indication of the presence of contamination due to its high toxicity. This paper presents a case study of contamination in a Fuel Retail Station by petroleum derivative products in the city of Natal. For identification and quantification of the hydrocarbons, EPA analytical methods were used. The values of benzene quantified by EPA method 8021b CG-PID/FID, ranged from 1.164 to 4.503 mg.Kg-1 in soil samples, and from 12.10 to 27,639 μg.L-1 in underground water samples. Among the PAHs, naphthalene and anthracene showed the most significant results in soil samples, 0.420 to 15.46 mg.Kg-1 and 0.110 to 0,970 mg.Kg-1, respectively. In underground water samples, the results for Naphthalene varied between 0.759 and 614.7 μg.L-1. PAHs were quantified by EPA Method 8270 for GCMS. All of the results for the chemical analysis were compared with the values for the CONAMA 420/2009 resolution. The results for benzene (27,639 μg.L-1) showed levels highly above the recommended by the CONAMA 420 resolution, wherein the maximum permissible for underground water is 5 μg.L-1. This is a worrying factor, since underground water makes up 70% of the city of Natal?s water supply / The retail fuel stations are partially or potentially polluters and generators of environmental accidents, potentially causing contamination of underground and surface water bodies, soil and air. Leaks in fuel retail stations? underground storage systems are often detected in Brazil and around the world. Monoaromatic hydrocarbons, BTEX (benzene, toluene, ethylbenzene and xylenes) and polycyclic aromatic hydrocarbons (PAHs) are an indication of the presence of contamination due to its high toxicity. This paper presents a case study of contamination in a Fuel Retail Station by petroleum derivative products in the city of Natal. For identification and quantification of the hydrocarbons, EPA analytical methods were used. The values of benzene quantified by EPA method 8021b CG-PID/FID, ranged from 1.164 to 4.503 mg.Kg-1 in soil samples, and from 12.10 to 27,639 μg.L-1 in underground water samples. Among the PAHs, naphthalene and anthracene showed the most significant results in soil samples, 0.420 to 15.46 mg.Kg-1 and 0.110 to 0,970 mg.Kg-1, respectively. In underground water samples, the results for Naphthalene varied between 0.759 and 614.7 μg.L-1. PAHs were quantified by EPA Method 8270 for GCMS. All of the results for the chemical analysis were compared with the values for the CONAMA 420/2009 resolution. The results for benzene (27,639 μg.L-1) showed levels highly above the recommended by the CONAMA 420 resolution, wherein the maximum permissible for underground water is 5 μg.L-1. This is a worrying factor, since underground water makes up 70% of the city of Natal?s water supply