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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

Utiliza??o de uma coluna de flota??o para remo??o de compostos org?nicos da ?gua de produ??o

Lima, L?da Maria Oliveira de 21 December 2009 (has links)
Made available in DSpace on 2014-12-17T15:01:48Z (GMT). No. of bitstreams: 1 LedaMOL_TESE.pdf: 3658937 bytes, checksum: 6ad7dbe6b2ec8a6f89d9264905ef89b6 (MD5) Previous issue date: 2009-12-21 / Innovative technologies using surfactant materials have applicability in several industrial fields, including petroleum and gas areas. This study seeks to investigate the use of a surfactant derived from coconut oil (SCO saponified coconut oil) in the recovery process of organic compounds that are present in oily effluents from petroleum industry. For this end, experiments were accomplished in a column of small dimension objectifying to verify the influence of the surfactant SCO in the efficiency of oil removal. This way, they were prepared emulsions with amount it fastens of oil (50, 100, 200 and 400 ppm), being determined the great concentrations of surfactant for each one of them. Some rehearsals were still accomplished with produced water of the industry of the petroleum to compare the result with the one of the emulsions. According to the experiments, it was verified that an increase of the surfactant concentration does not implicate in a greater oil removal. The separation process use gaseous bubbles formed when a gas stream pass a liquid column, when low surfactant concentrations are used, it occurs the coalescence of the dispersed oil droplets and their transport to the top of the column, forming a new continuous phase. Such surfactants lead to a gas-liquid interface saturation, depending on the used surfactant concentration, affecting the flotation process and influencing in the removal capacity of the oily dispersed phase. A porous plate filter, with pore size varying from 40 to 250 mm, was placed at the base of the column to allow a hydrodynamic stable operation. During the experimental procedures, the operating volume of phase liquid was held constant and the rate of air flow varied in each experiment. The resulting experimental of the study hydrodynamic demonstrated what the capturing of the oil was influenced by diameter of the bubbles and air flow. With the increase flow of 300 about to 900 cm3.min-1, occurred an increase in the removal of oil phase of 44% about to 66% and the removal kinetic of oil was defined as a reaction of 1? order / Tecnologias inovadoras que usam materiais tensoativos t?m aplicabilidade em v?rios campos industriais, dentre eles petr?leo e g?s natural. Este estudo busca investigar o uso de um tensoativo, derivado de ?leo de coco (OCS - ?leo de coco saponificado), no processo de recupera??o de compostos org?nicos presentes em efluentes oleosos da ind?stria de petr?leo. Para este fim, foram realizados experimentos em uma coluna de bancada objetivando verificar a influ?ncia do tensoativo OCS na efici?ncia de remo??o de ?leo. Desta forma, foram preparadas emuls?es com quantidades fixas de ?leo (50, 100, 200 e 400 ppm), determinandose a concentra??o ?tima de tensoativo para cada uma delas. Foram, tamb?m, realizados alguns ensaios com ?gua de produ??o da ind?stria de petr?leo, visando comparar o resultado com o das emuls?es. O processo de separa??o consiste no uso de bolhas gasosas formadas quando um fluxo de g?s passa em uma coluna l?quida, com concentra??es de tensoativo, ocorrendo a coalesc?ncia das gotas de ?leo dispersas e, consequentemente, o transporte delas ao topo da coluna, formando uma nova fase oleosa cont?nua. O processo fundamenta-se na satura??o de tensoativo na interface g?s-l?quido, dependendo da concentra??o de tensoativo usada, resultando na flota??o da fase ?leo dispersa. Um filtro de prato poroso, com tamanho de poro que varia de 40 a 250 μm, foi colocado ? base da coluna para permitir uma opera??o hidrodin?mica est?vel. Durante os procedimentos experimentais, o volume operacional da fase l?quida foi mantido constante e a taxa de fluxo de ar variada em cada experimento. Os resultados experimentais do estudo hidrodin?mico demonstraram que a captura do ?leo foi influenciada pelos di?metros das bolhas e vaz?es de ar. Com o aumento da vaz?o de 300 para 900 cm3.min-1, ocorreu um aumento de remo??o da fase ?leo de 44% para 66% e a cin?tica de remo??o do ?leo foi definida como uma rea??o de 1? ordem
2

Caracteriza??o morfoagron?mica e qu?mica de acessos de coqueiro-an?o e coqueiro-gigante

Sobral, Kamila Marcelino Brito 21 February 2017 (has links)
Submitted by Ricardo Cedraz Duque Moliterno (ricardo.moliterno@uefs.br) on 2017-12-18T21:43:02Z No. of bitstreams: 1 Tese_KamilaSobral.pdf: 1457947 bytes, checksum: 7c9ac5d23b1be9a47d34674e0490c6bf (MD5) / Made available in DSpace on 2017-12-18T21:43:02Z (GMT). No. of bitstreams: 1 Tese_KamilaSobral.pdf: 1457947 bytes, checksum: 7c9ac5d23b1be9a47d34674e0490c6bf (MD5) Previous issue date: 2017-02-21 / The genetic variability of the species Cocos nucifera L. that existing in Brazil is conserved in the International Coconut Germplasm Bank for Latin America and Caribe (ICG-LAC), which is located in the counties of Neopolis and Itaporanga d?Ajuda in the state of Sergipe, Brazil. Since from the establishment of the ICG-LAC some studies were carried out. However, this germplasm needs to be studied in depth comprising the morphoagronomical characterization, chemical and molecular evaluation in order to allow to estimate the genetic variability of the accessions. Thus, the aim of this work was to characterize morphologically coconut accessions (dwarfs and talls). The trials were carried out with eight tall coconut accessions in one cycle of production using 34 quantitative descriptors and with six dwarf coconut accessions in three cycles of production using 19 descriptors of fruits and 11 leave descriptors. The data obtained were subjected to univariate and multivariate analyses using the software GENES and Selegem. Among the accessions of tall coconuts the most dissimilar ones considering the morphoagronomical characters were Gigante-de-Rotuma and Gigante-do-Oeste Africano and they can be indicated as parents for coconut breeding programs. It was also found a great genetic variability among the coconut dwarf accessions of the ICG-LAC Bank, and this divergence was found to be consistent in the individual and joint analyses, including an analysis of maximum likelihood restricted (REML) taking into account a sample of morphological descriptors. The 14 coconut accessions (eight tall and six dwarfs) were used to perform a chemical evaluation of oil and their components in a cycle of crop production in two different field trials. It was found that some dwarf coconut accessions presented values of oil content similar to coconut tall accessions. Therefore, the best accessions can be exploited for coconut water as well as for production of oil and they can be selected as potential superior parents to be used in coconut breeding program. / A variabilidade gen?tica da esp?cie Cocos nucifera, L. existente no Brasil est? conservada no Banco Internacional de Germoplasma de Coco para Am?rica Latina e Caribe (ICG-LAC), localizado em Ne?polis e Itaporanga d?Ajuda em Sergipe, Brasil. Desde a implementa??o do ICG-LAC alguns estudos t?m sido realizados. No entanto, esse germoplasma precisa ser estudado em profundidade desde a caracteriza??o morfoagron?mica, qu?mica e molecular para se estimar a diversidade gen?tica dos acessos. Assim, o objetivo do trabalho foi caracterizar e avaliar morfoagronomicamente e quimicamente acessos de coqueiro-an?o e gigantes. Os experimentos foram conduzidos com oito acessos de coqueiros-gigantes em um ciclo de cultura e usando 34 descritores quantitativos e com seis acessos de coqueiros-an?es em tr?s ciclos da cultura utilizando-se 19 descritores de frutos e 11 descritores de folha. Os dados obtidos foram submetidos a an?lises univariadas e multivariadas usando o programa GENES e Selegem. Entre os acessos de coqueiros-gigantes avaliados os mais dissimilares pelas caracter?sticas agron?micas foram o Gigante-de-Rotuma e Gigante-do-Oeste-Africano, e estes podem ser indicados como genitores para programas de melhoramento. Foi encontrada tamb?m encontrada variabilidade gen?tica entre os acessos de coqueiro-an?o do banco ICG-LAC, diverg?ncia essa que se mostrou consistente nas an?lises individuais e conjuntas, incluindo uma an?lise de m?xima verossimilhan?a restrita (REML) usando uma amostra descritores morfol?gicos. Os 14 acessos de coqueiros (oito de gigantes e seis de an?es) foram analisados quanto ao teor de ?leo e seus componentes em um ciclo de cultura em dois experimentos separados. Constatou-se que alguns acessos de coqueiros-an?es apresentaram teor de ?leo pr?ximos dos valores obtidos pelos coqueiros-gigantes. Assim, os melhores acessos podem ser explorados tanto para ?gua de coco como para a produ??o de ?leo e s?o parentais potenciais para uso em programas de melhoramento do coqueiro.
3

Utiliza??o de uma coluna de flota??o para remo??o de compostos org?nicos da ?gua de produ??o

Lima, L?da Maria Oliveira de 21 December 2010 (has links)
Made available in DSpace on 2014-12-17T15:42:07Z (GMT). No. of bitstreams: 1 LedaMOL_TESE.pdf: 3658937 bytes, checksum: 6ad7dbe6b2ec8a6f89d9264905ef89b6 (MD5) Previous issue date: 2010-12-21 / Innovative technologies using surfactant materials have applicability in several industrial fields, including petroleum and gas areas. This study seeks to investigate the use of a surfactant derived from coconut oil (SCO saponified coconut oil) in the recovery process of organic compounds that are present in oily effluents from petroleum industry. For this end, experiments were accomplished in a column of small dimension objectifying to verify the influence of the surfactant SCO in the efficiency of oil removal. This way, they were prepared emulsions with amount it fastens of oil (50, 100, 200 and 400 ppm), being determined the great concentrations of surfactant for each one of them. Some rehearsals were still accomplished with produced water of the industry of the petroleum to compare the result with the one of the emulsions. According to the experiments, it was verified that an increase of the surfactant concentration does not implicate in a greater oil removal. The separation process use gaseous bubbles formed when a gas stream pass a liquid column, when low surfactant concentrations are used, it occurs the coalescence of the dispersed oil droplets and their transport to the top of the column, forming a new continuous phase. Such surfactants lead to a gas-liquid interface saturation, depending on the used surfactant concentration, affecting the flotation process and influencing in the removal capacity of the oily dispersed phase. A porous plate filter, with pore size varying from 40 to 250 mm, was placed at the base of the column to allow a hydrodynamic stable operation. During the experimental procedures, the operating volume of phase liquid was held constant and the rate of air flow varied in each experiment. The resulting experimental of the study hydrodynamic demonstrated what the capturing of the oil was influenced by diameter of the bubbles and air flow. With the increase flow of 300 about to 900 cm3.min-1, occurred an increase in the removal of oil phase of 44% about to 66% and the removal kinetic of oil was defined as a reaction of 1? order. / Tecnologias inovadoras que usam materiais tensoativos t?m aplicabilidade em v?rios campos industriais, dentre eles petr?leo e g?s natural. Este estudo busca investigar o uso de um tensoativo, derivado de ?leo de coco (OCS - ?leo de coco saponificado), no processo de recupera??o de compostos org?nicos presentes em efluentes oleosos da ind?stria de petr?leo. Para este fim, foram realizados experimentos em uma coluna de bancada objetivando verificar a influ?ncia do tensoativo OCS na efici?ncia de remo??o de ?leo. Desta forma, foram preparadas emuls?es com quantidades fixas de ?leo (50, 100, 200 e 400 ppm), determinandose a concentra??o ?tima de tensoativo para cada uma delas. Foram, tamb?m, realizados alguns ensaios com ?gua de produ??o da ind?stria de petr?leo, visando comparar o resultado com o das emuls?es. O processo de separa??o consiste no uso de bolhas gasosas formadas quando um fluxo de g?s passa em uma coluna l?quida, com concentra??es de tensoativo, ocorrendo a coalesc?ncia das gotas de ?leo dispersas e, consequentemente, o transporte delas ao topo da coluna, formando uma nova fase oleosa cont?nua. O processo fundamenta-se na satura??o de tensoativo na interface g?s-l?quido, dependendo da concentra??o de tensoativo usada, resultando na flota??o da fase ?leo dispersa. Um filtro de prato poroso, com tamanho de poro que varia de 40 a 250 μm, foi colocado ? base da coluna para permitir uma opera??o hidrodin?mica est?vel. Durante os procedimentos experimentais, o volume operacional da fase l?quida foi mantido constante e a taxa de fluxo de ar variada em cada experimento. Os resultados experimentais do estudo hidrodin?mico demonstraram que a captura do ?leo foi influenciada pelos di?metros das bolhas e vaz?es de ar. Com o aumento da vaz?o de 300 para 900 cm3.min-1, ocorreu um aumento de remo??o da fase ?leo de 44% para 66% e a cin?tica de remo??o do ?leo foi definida como uma rea??o de 1? ordem
4

Reavalia??o da efici?ncia de ?leo de coco saponificado e de sua microemuls?o como inibidores de corros?o em uma c?lula eletroqu?mica

Rocha, Thiago Ramalho da 25 April 2008 (has links)
Made available in DSpace on 2014-12-17T15:41:43Z (GMT). No. of bitstreams: 1 ThiagoRR.pdf: 1895833 bytes, checksum: 59d0cd6d03df2b5c8165e3ae0bf39a80 (MD5) Previous issue date: 2008-04-25 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / An interesting development in surfactants science and technology is their application as corrosion inhibitors, since they act as protective films over anodic and cathodic surfaces. This work aims to investigate the efficiency of saponified coconut oil (SCO) as corrosion inhibitor and of microemulsified system (SCO + butanol + kerosene oil + distilled water), in saline medium, using an adapted instrumented cell, via techniques involving linear polarization resistance (LPR) and mass loss coupons (MLC). For this, curves of efficiency versus SCO concentration (ranging between 0 and 75 ppm) have been constructed. According to the obtained results, the following efficiency levels were reached with OCS: 98% at a 75 ppm concentration via the LPR method and 95% at 75 ppm via the MLC method. The microemulsified system, for a concentration of 15 ppm of SCO, obtained maximum inhibition of 97% (LPR) and 93% (MLC). These data indicate that it is possible to optimize the use of SCO in similar applications. Previous works have demonstrated that maximal efficiencies below 90% are attained, typically 65% as free molecules and 77% in microemulsified medium, via the LPR method in a different type of cell. Therefore, it can be concluded that the adapted instrumented cell (in those used methods) showed to be an important tool in this kind of study and the SCO was shown effective in the inhibition of the metal / Tensoativos v?m sendo alvo de interesse como inibidores de corros?o, pois funcionam como pel?culas protetoras sobre ?reas an?dicas e cat?dicas. Este trabalho teve como objetivo avaliar a efici?ncia de inibi??o ? corros?o do tensoativo ?leo de coco saponificado (OCS) e do sistema icroemulsionado (OCS + butanol + querosene + ?gua destilada), em meio salino, utilizando-se uma c?lula instrumentada adaptada. A efic?cia do OCS foi avaliada utilizando-se os m?todos de resist?ncia de polariza??o linear (LPR) e cupons de perda de massa (CPM), tendo sido constru?das curvas de efici?ncia versus concentra??o de OCS (variando de 0 a 75 ppm). De acordo com os resultados obtidos, verificou-se que este tensoativo apresenta a seguinte ordem de efici?ncia de inibi??o ? corros?o: para uma concentra??o de 75 ppm, 98% pelo m?todo LPR e 95% pelo m?todo CPM. O sistema microemulsionado, para uma concentra??o de 15 ppm de OCS, obteve inibi??o m?xima de 97% (LPR) e 93% (CPM). Atrav?s deste trabalho foi poss?vel otimizar o uso do tensoativo OCS, que em trabalhos anteriores mostrou efic?cia m?xima inferior a 90% (63% na sua forma livre e 77% na sua forma microemulsionada, pelo m?todo LPR, em um outro tipo de c?lula). Conclusivamente, pode-se dizer que a c?lula instrumentada adaptada (nos m?todos utilizados) provou ser uma ferramenta importante neste tipo de estudo e o OCS mostrou-se efetivo na inibi??o do metal

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