Made available in DSpace on 2014-12-17T15:01:13Z (GMT). No. of bitstreams: 1 ValdirCRN.pdf: 131656 bytes, checksum: 4153e21d4042d68f4cdd2a9f2c14b5e9 (MD5) Previous issue date: 2007-08-31 / Petroleum is a complex combination of various classes of hydrocarbons, with paraffinic, naphtenic and aromatic compounds being those more commonly found in its composition. The recent changes in the world scenario, the large reserves of heavy oils and also the lack of new discoveries of large petroleum fields are indications that, in the near future, the oil recovery by conventional methods will be limited. In order to increase the efficiency of the extraction process, enhanced recovery methods are cited in applications where conventional techniques have proven to be little effective. The injection of surfactant solutions as an enhanced recovery method is advantageous in that surfactants are able to reduce the interfacial tensions between water and oil, thus augmenting the displacement efficiency and, as a consequence, increasing the recovery factor. This work aims to investigate the effects of some parameters that influence the surfactant behavior in solution, namely the type of surfactant, the critical micelle concentration (CMC) and the surface and interface tensions between fluids. Seawater solutions containing the surfactants PAN, PHN and PJN have been prepared for presenting lower interfacial tensions with petroleum and higher stability under increasing temperature and salinity. They were examined in an experimental apparatus designed to assess the recovery factor. Botucatu (Brazil) sandstone plug samples were submitted to assay steps comprising saturation with seawater and petroleum, conventional recovery with seawater and enhanced recovery with surfactant solutions. The plugs had porosity between 29.6 and 32.0%, with average effective permeability to water of 83 mD. The PJN surfactant, at a concentration 1000% above CMC in water, had a higher recovery factor, causing the original oil in place to be recovered by an extra 20.97%, after conventional recovery with seawater / O petr?leo ? uma combina??o complexa de v?rias s?ries de hidrocarbonetos, sendo as mais comumente encontradas as parafinicas, naft?nicas e arom?ticas. As recentes mudan?as no cen?rio mundial, as grandes reservas de ?leos pesados, bem como a escassez de descobertas de grandes campos de petr?leo, indicam que em um futuro pr?ximo a recupera??o de ?leo por m?todos convencionais ser? limitada. Para aumentar a efici?ncia do processo de extra??o, faz-se uso dos m?todos avan?ados de recupera??o para agir nos pontos onde o processo convencional mostrou-se pouco eficiente. A inje??o de solu??o de tensoativo, como um m?todo avan?ado de recupera??o mostra-se vantajosa, pois os tensoativos t?m a finalidade de reduzir as tens?es interfaciais entre a ?gua e o ?leo, ampliando a efici?ncia de deslocamento e, conseq?entemente, aumentando o fator de recupera??o. Este trabalho se prop?s a estudar os efeitos dos par?metros que influenciam as solu??es de tensoativos, como: tipo de tensoativo, concentra??o micelar cr?tica e tens?o superficial e interfacial entre os fluidos. As solu??es com ?gua do mar dos tensoativos PAN, PHN e PJN, por apresentarem menores tens?es interfaciais com o petr?leo e maior estabilidade com o aumento da temperatura e salinidade, foram estudadas em um aparato experimental para avalia??o do fator de recupera??o. Os testemunhos de arenito Botucatu foram submetidos a etapas de satura??o com ?gua do mar e petr?leo, recupera??o convencional com ?gua do mar e recupera??o avan?ada com solu??es de tensoativos. Os testemunhos apresentaram porosidade entre 29,6 e 32,0%, com permeabilidade m?dia efetiva ? ?gua de 83 mD. O tensoativo PJN, com concentra??o de 1000% acima da CMC apresentou maior fator de recupera??o, aumentando em 20,97% a recupera??o do ?leo original in place ap?s a recupera??o convencional com ?gua do mar

Made available in DSpace on 2014-12-17T15:01:28Z (GMT). No. of bitstreams: 1 AnaPJS_DISSERT.pdf: 3475683 bytes, checksum: 0a1aca9ea1cc67fdf9f54a968369acd0 (MD5) Previous issue date: 2012-02-08 / The large investment in exploration activities offshore Brazil has generated new findings, generally in carbonate reservoirs, with different wettability conditions usually considered in the sandstone, strongly water-wet. In general, the carbonates reservoirs tend to be oil-wet, it difficult to mobilize of oil these reservoirs. These oils can be mobilized by different methods, or it may reverse the wettability of the surface of the reservoir and facilitate the flow of oil, improving production rates. Thus, the objective of this work was to study the influence of inversion on the wettability of the rock in the production and recovery of petroleum from carbonate reservoirs, using microemulsions. Three systems were chosen with different classes of surfactants: a cationic (C16TAB), an anionic (SDS) and nonionic (Unitol L90). Studies of the influence of salinity on the formation of the microemulsion as well as the characterization of fluids using density and viscosity measurements were also performed. To verify the potential of microemulsion systems in changing the wettability state of the chalk oil-wet to water-wet, contact angle measurements were performed using chalk of neutral-wet as surface material. Overall, with respect to the ionic character of the surfactants tested, the cationic surfactant (C16TAB) had a greater potential for reversal in wettability able to transform the rock wettability neutral to strongly water-wet, when compared with the anionic surfactant (SDS) and nonionic (Unitol L90), which showed similar behavior, improving the wettability of the rock to water. The microemulsions of all surfactants studied were effective in oil recovery, resulting in 76.92% for the system with C16TAB, 67.42% for the SDS and 66.30% for Unitol L90 of residual oil / O grande investimento em atividades explorat?rias no mar brasileiro tem gerado novas descobertas, geralmente em reservat?rios carbon?ticos, com condi??es de molhabilidade diferentes das usualmente consideradas em reservat?rios aren?ticos, fortemente molh?veis ? ?gua. De uma maneira geral, os reservat?rios carbon?ticos tendem a ser molh?veis ao ?leo, dificultando a mobiliza??o do ?leo no reservat?rio. Esses ?leos podem ser mobilizados por diferentes m?todos, ou ainda, pode-se inverter a molhabilidade da superf?cie do reservat?rio e facilitar o escoamento do ?leo, melhorando os ?ndices de produ??o. Desta forma, o objetivo deste trabalho foi estudar a influ?ncia da invers?o na molhabilidade da rocha na produ??o e recupera??o de petr?leo de reservat?rios carbon?ticos, utilizando sistemas microemulsionados. Foram escolhidos tr?s tensoativos de classes diferentes: um cati?nico (C16TAB), um ani?nico (SDS) e um n?o-i?nico (Unitol L90). Estudos da influ?ncia da salinidade na forma??o da microemuls?o, bem como a caracteriza??o dos fluidos atrav?s de medidas de densidade e viscosidade, tamb?m foram realizados. Para verificar o potencial dos sistemas microemulsionados em alterar a molhabilidade da rocha carbon?ticas de molh?vel ao ?leo para molh?vel a ?gua, medidas de ?ngulo de contato foram realizadas utilizando calc?rio de molhabilidade neutra como material de superf?cie. Pode-se observar, com rela??o ao car?ter i?nico dos tensoativos testados, que o tensoativo cati?nico (C16TAB) apresentou um potencial maior de invers?o na molhabilidade conseguindo transformar a rocha de molhabilidade neutra para fortemente molh?vel ? ?gua, quando comparado aos demais tensoativos, ani?nico (SDS) e n?o-i?nico (Unitol L90), que apresentaram comportamento semelhante entre eles, melhorando tamb?m a molhabilidade da rocha ? ?gua, mas em menor intensidade. As microemuls?es de todos os tensoativos estudados mostraram-se efetivas na recupera??o de petr?leo, obtendo-se 76,92% para o sistema com C16TAB, 67,42% para o SDS e 66,30% para o Unitol L90 de recupera??o do ?leo residual in place

Made available in DSpace on 2014-12-17T15:01:47Z (GMT). No. of bitstreams: 1 TulioYFV_D.pdf: 3087566 bytes, checksum: 98d82de1a3cf355e814daf66c053ad55 (MD5) Previous issue date: 2009-07-10 / The high concentration of residual oil is one of the greatest problems found in petroleum mature fields. In these reservoirs, different enhanced oil recovery methods (EOR) can be used, highlighting the microemulsion injection. The microemulsion has showed to be efficient in petroleum recovery due to its ability to promote an efficient displacement of the petroleum, acting directly in the residual oil. In this way, this research has as objective the study of microemulsion systems obtained using a commercial surfactant (TP), determining microemulsion thermal stabilities and selecting points inside the pseudoternary phases diagram, evaluating its efficiencies and choosing the best system, that has the following composition: TP as surfactant (S), isopropyl alcohol as co-surfactant (C), kerosene as oil phase, water as aqueous phase, C/S ratio = 1, and 5% sodium p-toluenesulfonate as hydrotope; being observed the following parameters for the selection of the best pseudoternary phases diagram: C/S ratio, co-surfactant nature and addition of hydrotope to the system. The efficiency in petroleum recovery was obtained using two sandstone formation systems: Assu and Botucatu. The study of thermal stabilities showed that as the concentration of active matter in the system increased, the thermal stability also increased. The best thermal stability was obtained using point F (79.56 0C). The system that presented the best recovery percentile between the three selected (3) was composed by: 70% C/S, 2% kerosene and 28% water, with 94% of total recovery efficiency and 60% with microemulsion injection, using the Botucatu formation, that in a general way presented greater efficiencies as compared with the Assu one (81.3% of total recovery efficiency and 38.3% with microemulsion injection) / Um dos grandes problemas encontrados nos campos maduros ? a alta satura??o de ?leo residual. Nesses campos, a inje??o de microemuls?o pode ser utilizada na recupera??o de petr?leo, pois esta tem se mostrado eficiente na recupera??o de petr?leo devido ? obten??o de um deslocamento eficiente do petr?leo, atuando diretamente no ?leo residual. Esse trabalho tem como objetivo estudar sistemas microemulsionados para a recupera??o de petr?leo, determinando suas estabilidades t?rmicas e avaliando suas efici?ncias de recupera??o. Os sistemas microemulsionados selecionados foram obtidos escolhendo-se pontos no diagrama de fases, com a seguinte composi??o: co-tensoativo, ?lcool iso-prop?lico (raz?o C/T=1), querosene, tensoativo (TP) e 5% de ptoluenosulfonato de s?dio (hidr?tropo). Para a escolha desse diagrama de fases foram avaliadas: a raz?o C/T, o co-tensoativo e a adi??o de hidr?tropo ao sistema. As forma??es estudadas na recupera??o de petr?leo foram: a Assu e a Botucatu. O estudo das estabilidades t?rmicas do sistema apontou que ? medida que se aumentou a concentra??o de mat?ria ativa, aumentava-se a estabilidade t?rmica do mesmo. A maior estabilidade t?rmica foi obtida no ponto F (79,56 0C). Dos pontos selecionados (3) o sistema que apresentou o maior percentual de recupera??o foi obtido com o sistema constitu?do de 70% C/T, 2% de querosene e 28% de ?gua, levando a 94 % de efici?ncia total e 60% de inje??o de microemuls?o, utilizando-se a forma??o Botucatu, que no geral apresentou efici?ncias maiores do que a forma??o Assu (81,3 % de efici?ncia total e 38,3% com microemuls?o)

Made available in DSpace on 2014-12-17T15:03:30Z (GMT). No. of bitstreams: 1 LilianeFGL_DISSERT.pdf: 931554 bytes, checksum: 0bbe7c36b3d8afca89214b8b2d97bd81 (MD5) Previous issue date: 2012-12-07 / This study investigated the influence of the molar ratio, the phosphorus initial concentration, the mixture gradient, mixing time, pH and the secondary nucleation on struvite s crystallization in synthetic water in batch reactors. The study was divided into two stages. The first investigated struvite s crystallization at different Mg:N:P molar ratios and at different initial concentrations of magnesium, nitrogen and phosphorus. It was also evaluated the importance of secondary nucleation on the struvite s crystallization. In the second, five parameters were tested to evaluate their influence on the struvite s crystallization, which were: Mg:N:P molar ratio, initial concentration of phosphate, mixing time, mixture gradient and pH. The best conditions for struvite s crystallization were: Mg:N:P = 1,3:1:1 molar ratio; mixture gradient = 60 rpm, pH = 10.0, mixing time = 5 minutes and high initial concentrations of the constituent ions of struvite. Furthermore, the use of struvite crystals as seed influenced positively on the struvite s crystallization / O presente estudo investigou a influ?ncia da raz?o molar, da concentra??o inicial de f?sforo, do gradiente de mistura, do tempo de mistura, do pH e da nuclea??o secund?ria na cristaliza??o de estruvita em ?gua sint?tica, em reatores em batelada. A pesquisa foi dividida em duas etapas. A primeira investigou a cristaliza??o da estruvita em ?gua sint?tica em diferentes raz?es molares Mg:N:P e concentra??es iniciais de magn?sio, nitrog?nio e f?sforo, sendo tamb?m avaliada a import?ncia da nuclea??o secund?ria na cristaliza??o da estruvita. Na segunda etapa, cinco par?metros foram testados para avaliar a influ?ncia destes na cristaliza??o da estruvita, quais sejam: raz?o molar Mg:N:P, concentra??o inicial de f?sforo, gradiente de mistura, tempo de mistura e pH. As melhores condi??es observadas para a cristaliza??o de estruvita foram: raz?o molar Mg:N:P = 1,3:1:1; gradiente de mistura = 60 rpm; pH = 10,0; tempo de mistura = 5 minutos e elevadas concentra??es iniciais dos ?ons constituintes da estruvita. Al?m disso, a utiliza??o de cristais de estruvita como semente influenciou positivamente na cristaliza??o da estruvita

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-01-13T12:25:48Z No. of bitstreams: 1 MarcelAraujoRocha_DISSERT.pdf: 5011334 bytes, checksum: d4996c7516aeda7455db92bc1ebfc1d5 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-01-23T13:23:05Z (GMT) No. of bitstreams: 1 MarcelAraujoRocha_DISSERT.pdf: 5011334 bytes, checksum: d4996c7516aeda7455db92bc1ebfc1d5 (MD5) / Made available in DSpace on 2017-01-23T13:23:05Z (GMT). No. of bitstreams: 1 MarcelAraujoRocha_DISSERT.pdf: 5011334 bytes, checksum: d4996c7516aeda7455db92bc1ebfc1d5 (MD5) Previous issue date: 2016-03-14 / A explora??o de reservas de hidrocarbonetos pesados e extrapesados ? de interesse primordial para muitas companhias de petr?leo, uma vez que, a magnitude desses recursos representa parte da energia mundial. A produ??o de ?leo pesado, a partir de dep?sitos subterr?neos, ? complexa, at? mesmo sob as melhores circunst?ncias, devido principalmente ? elevada viscosidade do ?leo. Para melhor desenvolver o processo de produ??o, tornando-o eficiente, de maneira que os fluidos que n?o seriam produzidos consigam chegar ? superf?cie, foram desenvolvidos m?todos de recupera??o convencionais e especiais, para obten??o de um maior fator de recupera??o e, consequentemente, uma maior lucratividade na opera??o de explota??o dessas jazidas. Para reduzir a alta viscosidade e as elevadas tens?es interfaciais, foram desenvolvidos os m?todos t?rmicos. Nesse trabalho, simulou-se a inje??o continua de vapor, com po?os injetores verticais e horizontais, para desenvolver um reservat?rio com caracter?sticas do Nordeste brasileiro, de ?leo pesado, atrav?s da condu??o dos fluidos produzidos com po?o horizontal. Foram feitas an?lises t?cnicas e econ?micas dos modelos que diferiam quanto ?s suas restri??es e arranjos estruturais do sistema. Na configura??o horizontal se observou a influ?ncia da vaz?o de inje??o, da dist?ncia vertical e da dist?ncia lateral sobre o fator de recupera??o. Na configura??o vertical se analisou a influ?ncia da vaz?o de inje??o, da completa??o dos injetores, da dist?ncia lateral e da quantidade de po?os injetores sobre o fator de recupera??o. Diante dos modelos proposto, analisou-se a produ??o acumulada de ?leo, o Volume Poroso Injetado, a forma??o das c?maras de vapor e o Valor Presente L?quido. Tecnicamente, os modelos em que se injetou vapor com po?os verticais obtiveram maior fator de recupera??o de ?leo, j? os modelos horizontais se sobressa?ram economicamente. / The reserves exploration of heavy and extra heavy hydrocarbon is of prime interest to many oil companies, since the magnitude of these resources the magnitude of these resources still stands out on the global and Brazilian energy matrix. The production of heavy oil, from the underground deposits is complex, even on the best of circumstances, mainly due to the high viscosity of the oil. To further develop the process of production, making it efficient, so that the fluids that would not be produced get to reach the surface, complementary recovery methods and advanced were developed to obtain a higher recovery factor and, hence, greater profitability in operation exploitation of these deposits. To combat the high viscosity and high interfacial tensions, thermal methods were developed. In this work, the steam injection continues was simulated in vertical and horizontal injection wells, to develop a reservoir with characteristics of the Brazilian Northeast of heavy oil, by conducting fluid produced with horizontal well. Technical and economic analyzes were made of the models that differ in their structural constraints and system arrangements. In horizontal configuration was observed the influence of the injection flow, of the vertical distance and of the lateral distance over the recovery factor. In vertical configuration was analyzed the influence of the injection flow, of the injection wells completion, of the lateral distance and the amount of injection wells over the recovery factor. Faced the proposed models, was analyzed the cumulative oil production, the Pore Volume Injected, the formation of steam chambers and the Net Present Value. Technically, the models in which steam is injected with vertical wells had higher recovery factor of oil, since the horizontal models stood out economically.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-02-10T16:44:41Z No. of bitstreams: 1 ZildianyIbiapinaMeneses_TESE.pdf: 5538896 bytes, checksum: aeb6e8b7a1071f0fe7d56cd5089c7e65 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-02-10T21:58:03Z (GMT) No. of bitstreams: 1 ZildianyIbiapinaMeneses_TESE.pdf: 5538896 bytes, checksum: aeb6e8b7a1071f0fe7d56cd5089c7e65 (MD5) / Made available in DSpace on 2017-02-10T21:58:03Z (GMT). No. of bitstreams: 1 ZildianyIbiapinaMeneses_TESE.pdf: 5538896 bytes, checksum: aeb6e8b7a1071f0fe7d56cd5089c7e65 (MD5) Previous issue date: 2016-05-23 / As nanoemuls?es s?o sistemas geralmente compostos por tensoativos, fase aquosa e fase oleosa. Podem variar de acordo com a composi??o, tamanho das got?culas dispersas, aspecto, aplica??es, dentre outros. Apresentam got?culas dispersas em escala nanom?trica, estabilidade cin?tica e aspecto transparente a transl?cido. Dentre suas vantagens, destaca-se a maior superf?cie de contato devido ao tamanho das got?culas dispersas, associado ? menor quantidade de mat?ria ativa. Este trabalho prop?e produzir novas nanoemuls?es atrav?s da dilui??o de microemuls?o com sua fase aquosa ou com fase aquosa polim?rica salina, e aplica??o na recupera??o de petr?leo em rochas carbon?ticas. A microemuls?o precursora ? composta por tensoativos ani?nico e n?o i?nico (UNT-L90 e sab?o base), cotensoativo (n-butanol), fase oleosa (querosene) e fase aquosa (solu??o de NaCl a 3,50%). Os sistemas nanoemulsionados foram estudados em rela??o ao percentual de tensoativos (1,00%, 1,25%, 2,00%, 2,50%, 5,00% e 7,00%) e ? presen?a de pol?meros (ani?nico e cati?nico, a 0,08%). Os sistemas propostos neste estudo foram caracterizados usando as seguintes t?cnicas: tamanho de got?cula, turbidez, tens?o superficial, tens?o interfacial, condutividade el?trica, pH, ?ndice de refra??o, densidade, reologia e SAXS. A microemuls?o e as nanoemuls?es, sem pol?mero, foram caracterizadas como fluidos Newtonianos, enquanto as nanoemuls?es polim?ricas como fluidos pseudopl?sticos. A microemuls?o foi termodinamicamente est?vel, transparente e com got?culas monodispersas, com 11,8 nm de di?metro. Os sistemas nanoemulsionados foram metaest?veis, com got?culas variando de 16,80 nm a 61,40 nm. Os sistemas microemulsionado e nanoemulsionados apresentaram micelas diretas do tipo ?miolo-casca? em seu interior. A microemuls?o e algumas nanoemuls?es estudadas foram utilizadas na recupera??o avan?ada de petr?leo, aplicadas a um reservat?rio carbon?tico contendo ?leo leve. Os melhores resultados foram de 99,56% e 75,18% de extra??o do ?leo remanescente, para a microemuls?o e nanoemuls?o, respectivamente; com recupera??es totais de ?leo original de 99,73% e 83,28%. O efeito sin?rgico entre o meio salino, micelas e pol?mero favoreceu a recupera??o de ?leo com as nanoemuls?es; cujo melhor resultado foi obtido com a NanoD2, composta por 2,50% de tensoativos, 3,50% de NaCl e 0,08% do pol?mero AN 934 PWG; embora as propriedades da rocha tamb?m tenham influ?ncia. O trabalho mostrou que nanoemuls?es e microemuls?es podem ser alternativas vi?veis para aplica??o em recupera??o avan?ada de petr?leo. / Nanoemulsions are systems generally composed by surfactant, aqueous phase and oil phase. These systems may vary according to their composition, size of dispersed droplets, appearance, applications, among others. They have nano-scale dispersed droplets, kinetic stability and an appearance from transparent to translucent. Among their advantages, it may be highlighted the large contact surface, due to the size of the dispersed droplets, associated with smaller amount of active matter. This research proposes the production of new nanoemulsions, through the dilution of microemulsion, with its aqueous phase or with saline polymeric aqueous phase, and their use to recover oil in carbonate rocks. The precursor microemulsion is composed of nonionic and anionic surfactants (UNT-L90 and soap base), cosurfactant (n-butanol), oil phase (kerosene) and aqueous phase (NaCl solution at 3.50%). The nanoemulsionated systems were studied based on the percentage of surfactants (1.00%, 1.25%, 2.00%, 2.50%, 5.00% and 7.00%) and on the presence of polymers (anionic and cationic, at 0.08%). The proposed systems were characterized by using the following techniques: droplet size, turbidity, surface tension, interfacial tension, electrical conductivity, pH, refractive index, density, rheology, and SAXS. The microemulsion and the nanoemulsions, without polymers, were characterized as Newtonian fluids, while the polymeric nanoemulsions were characterized as pseudoplastic fluids. The microemulsion was thermodynamically stable, transparent and had monodispersed droplets with a diameter of 11.80 nm. The nanoemulsionated systems were metastable, with droplets ranging from 16.80 nm to 61.40 nm. The microemulsionated and nanoemulsionated systems presented direct micelles, with a core-shell inner type. The microemulsion and some studied nanoemulsions were applied as an enhanced oil recovery method, through carbonate rocks containing light oil. The best results extracted 99.56% and 75.18% of the remaining oil, for the microemulsion and nanoemulsion, respectively, with total oil recovery of 99.73% and 83.28%. The synergic effect among saline medium, micelles and polymer favored the oil recovery with nanoemulsions; whose best result was obtained by NanoD2, composed of 2.50% surfactants, 3.50% NaCl and 0.08% of the AN 934 PWG polymer; although the rock properties also influences the process. The work showed that nanoemulsions and microemulsions can be viable alternatives for application in enhanced oil recovery.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-05-24T19:46:43Z No. of bitstreams: 1 IsmaelSoaresPereira_DISSERT.pdf: 2056219 bytes, checksum: f9ca833b84098708ca945405d2a0807f (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-05-30T23:57:27Z (GMT) No. of bitstreams: 1 IsmaelSoaresPereira_DISSERT.pdf: 2056219 bytes, checksum: f9ca833b84098708ca945405d2a0807f (MD5) / Made available in DSpace on 2017-05-30T23:57:27Z (GMT). No. of bitstreams: 1 IsmaelSoaresPereira_DISSERT.pdf: 2056219 bytes, checksum: f9ca833b84098708ca945405d2a0807f (MD5) Previous issue date: 2017-02-20 / Este trabalho analisa a compet?ncia em informa??o dos estudantes do Curso de Gradua??o em Medicina da Escola Multicampi de Ci?ncias M?dicas do Rio Grande do Norte, na perspectiva do acesso eficiente ? literatura cient?fica. ? um estudo descritivo com abordagem quantitativa que, mediante levantamento censit?rio, explora a percep??o e o desempenho da compet?ncia em informa??o de 37 alunos do quarto semestre. Utiliza question?rio como instrumento de coleta de dados, sendo esse adaptado do modelo aplicado por Guerrero (2009), composto por 20 quest?es fechadas. Constata que os discentes selecionam adequadamente as palavras-chave que melhor representam o assunto de um problema de pesquisa e est?o habituados a usar cat?logos de bibliotecas. Identifica que apesar da prefer?ncia pela internet para acessar a literatura cient?fica, a maioria sente dificuldades em realizar pesquisas nas bases remotas de dados, destacando como principal limita??o o uso de recursos de busca. O m?todo de truncamento ? pouco utilizado por eles e muitos n?o sabem para que serve. Boa parte tamb?m n?o compreende as fun??es dos operadores l?gicos booleanos. Por meio de autoavalia??o e an?lise individual de desempenho, confirma a necessidade de aperfei?oar nos estudantes as habilidades t?cnicas necess?rias ao acesso efetivo de informa??es cient?ficas. Recomenda a implementa??o de um m?dulo espec?fico no curr?culo do curso ou a realiza??o peri?dica de oficinas na biblioteca como alternativas para desenvolver a compet?ncia em informa??o. Conclui que essa compet?ncia ? bastante relevante para a forma??o dos futuros m?dicos, pois possibilita a eles adquirir conhecimentos para usar tecnologias e informa??es em prol dos cuidados de sa?de da popula??o. / This work analyzes the information literacy of students of the Medical Graduation Course of Multicampi School of Medical Sciences from Rio Grande do Norte, in the perspective of efficient access to scientific literature. It is a descriptive study with quantitative approach that, through a census survey, explores the perception and performance of the information literacy of 37 students fourth semester. It uses a questionnaire as a data collection instrument, which is adapted from the model applied by Guerrero (2009), composed of 20 closed-type questions. Note that students select appropriately the keywords that best represent the subject of a search problem and are accustomed to using library catalogs. It identifies that despite the preference for the internet to access the scientific literature, most of them find it difficult to conduct searches on the remote databases, highlighting as the main limitation the use of search resources. The truncation method is little used by them and many do not know what it is for. Much of it does not understand the functions of Boolean logic operators. Through self-assessment and individual performance analysis, it confirms the need to perfect in students the technical skills necessary for effective access to scientific information. It recommends the implementation of a specific module in the curriculum of the course or the periodic realization of workshops in the library as alternatives to develop information literacy. It concludes that this competence is very relevant for the training of future doctors, since it enables them to acquire knowledge to use technologies and information for the health care of the population.

Submitted by Elba Lopes (elba.lopes@fecap.br) on 2017-04-04T21:36:02Z No. of bitstreams: 2 Paulo Rog??rio Gomes Gon??alves.pdf: 5642577 bytes, checksum: deb01b20b62885c60e71197343469d33 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-04-04T21:36:02Z (GMT). No. of bitstreams: 2 Paulo Rog??rio Gomes Gon??alves.pdf: 5642577 bytes, checksum: deb01b20b62885c60e71197343469d33 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-03-17 / This study sought to investigate how the strategic positioning of Accounting Organizations with the implementation of the Public Digital Bookkeeping System - SPED. For this carried out a quantitative classification, descriptive and survey, in which a questionnaire was applied to obtain the data. The results showed that 83.30% of survey participants accounting organizations opted for the generic strategy of "differentiation" (PORTER, 2004), that is, they positioned themselves in order to provide services with higher quality and invest in their organizational structures, seeking to offer superior benefits those of competitors. / Este trabalho procurou investigar qual o posicionamento estrat??gico das organiza????es cont??beis com a implanta????o do Sistema P??blico de Escritura????o Digital - SPED. Para isso realizou-se uma pesquisa de classifica????o quantitativa, descritiva e de levantamento (survey), no qual foi aplicado um question??rio para a obten????o dos dados. Os resultados demonstraram que 83,30% das organiza????es cont??beis participantes da pesquisa optaram pela estrat??gia gen??rica de "Diferencia????o" (PORTER, 2004), ou seja, se posicionaram visando prestar servi??os com maior qualidade e investir nas suas estruturas organizacionais, procurando oferecer benef??cios superiores aos dos concorrentes.

Submitted by Ricardo Cedraz Duque Moliterno (ricardo.moliterno@uefs.br) on 2017-11-28T21:38:06Z No. of bitstreams: 1 dissertacao-versao-final.pdf: 2717503 bytes, checksum: a1476bba65482b40daa1a139191ea912 (MD5) / Made available in DSpace on 2017-11-28T21:38:06Z (GMT). No. of bitstreams: 1 dissertacao-versao-final.pdf: 2717503 bytes, checksum: a1476bba65482b40daa1a139191ea912 (MD5) Previous issue date: 2017-07-17 / With the popularization of databases containing objects with spatial and textual information (spatio-textual object), the interest in new queries and techniques for retrieving these objects have increased. In this scenario, the main query is the the top-k spatio-textual query. This query retrieves the k best spatio-textual objects considering the distance of the object to the query location and the textual similarity between the query keywords and the textual information of the objects. However, most the studies related to top-k spatio-textual query are performed in centralized environments, not addressing real world problems such as scalability. In this paper, we study different strategies for partitioning the data and processing the top-k spatio-textual query in a distributed environment. We evaluate each strategy in a real distributed environment, employing real datasets. / Com a populariza??o de bases de dados contendo objetos que possuem informa??o espacial e textual (objeto espa?o-textual), aumentou o interesse por novas consultas e t?cnicas capazes de recuperar esses objetos de forma eficiente. Uma das principais consultas para objetos espa?o-textuais ? a consulta espa?o-textual top-k. Essa consulta visa recuperar os k melhores objetos considerando a dist?ncia do objeto at? um local informado na consulta e a similaridade textual entre palavras-chave de busca e a informa??o textual dos objetos. No entanto, a maioria dos estudos para consultas espa?o-textual top-k assumem ambientes centralizados, n?o abordando problemas frequentes em aplica??es do mundo real como escalabilidade. Nesta disserta??o s?o estudadas diferentes formas de particionar os dados e o impacto destes particionamentos no processamento da consulta espa?o-textual top-k em um ambiente distribu?do. Todas as estrat?gias propostas s?o avaliadas em um ambiente distribu?do real, utilizando dados reais.

Made available in DSpace on 2015-12-03T18:32:58Z (GMT). No. of bitstreams: 1 Washington_Cristiano_Kato.pdf: 2640570 bytes, checksum: b60a0347a8f8e02ebfd2c4386fb5bd12 (MD5) Previous issue date: 2002-10-28 / This research paper aims at analyzing the information system of a firm in the transportation sector, utilizing the case-study methodology. The importance of information resources was stated by its executives according to the strategy established by the company, results being validated by a questionnaire applied to a broader group. The core question of the research was to observe how the information systems are in line with the needs of the company's strategic management according to its officers. As a result of the research, different opinions were found at different hierarchical levels and also among functional areas which were studied based on the usefulness of the main systems of the organization, showing either lack of formal definitions according to the strategy adopted or at least not disseminated within the company. The research was developed through surveys with the executives of the company and a questionnaire was answered by a great majority of the staff from all departments of the company. / Este trabalho de pesquisa tem por objetivo analisar o sistema de informa????o de uma empresa do setor de transporte, utilizando o m??todo de estudo de caso. Procurou-se determinar a import??ncia atribu??da por seus executivos aos recursos de informa????o, mapeados em rela????o ??s estrat??gias adotadas pela empresa, validando os resultados com a aplica????o de um question??rio dirigido a um grupo maior de pessoas da empresa. A quest??o principal da pesquisa foi observar em que medida os sistemas de informa????o adotados pela empresa est??o em linha com as necessidades da gest??o estrat??gica da mesma, na opini??o dos seus dirigentes. Como resultado da pesquisa, constatou-se que h?? diverg??ncias de opini??o entre os niveis hier??rquicos e tamb??m entre as ??reas funcionais pesquisadas quanto ?? utilidade dos principais sistemas da organiza????o, indicando n??o haver defini????es formais em rela????o ?? estrat??gia em curso, ou pelo menos n??o est??o disseminados na empresa. Para o desenvolvimento da pesquisa foram entrevistados os executivos da empresa. Foi aplicado, ainda, um question??rio ?? grande maioria dos funcion??rios de escrit??rio de todos os setores da empresa.