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Fotografia cervical digital para rastreamento de câncer de colo uterino e suas lesões precursorasHillmann, Elise de Castro January 2010 (has links)
Background: O câncer de colo uterino é um grande problema de saúde pública no Brasil e no mundo. Atinge cerca de meio milhão de mulheres, sendo que 50 % destas morrem. Os métodos visuais, alternativos á citologia e viáveis para países em desenvolvimento, têm sido avaliados mais intensamente na última década. Objetivos: Avaliar o desempenho da Fotografia Cervical Digital (FCD) na detecção do câncer do colo de útero e de suas lesões precursoras. Métodos: 176 mulheres foram avaliadas pelos métodos de Inspeção Visual com ácido acético (VIA), Inspeção Visual com lugol (VILI), Fotografia Cervical Digital com ácido acético (FCDA) e Fotografia Cervical Digital com lugol (FCDL). Destas, 36 foram classificadas pela histologia. Resultados: A concordância entre avaliadores observou valores de Kappa: Fotografia Cervical Digital com ácido acético, K=0,441, e Fotografia Cervical Digital com lugol, K=0,533. A concordância entre as inspeções a olho nu e as fotografias cervicais digitais após a utilização de ácido acético no colo uterino, K=0,559, e a concordância após a utilização da solução de lugol, K=0,507, considerada como concordância moderada em ambos os casos. Das 36 pacientes com avaliações histológicas, 20 dos 25 casos positivos foram corretamente avaliados tanto pela FCDA, como pela FCDL, demonstrando resultados similares aos descritos anteriormente. Conclusão: A FCD é um método promissor para o rastreamento do câncer de colo de útero e suas lesões precursoras, para países em desenvolvimento. / Background: Uterine cervix cancer is a major public health problem in Brazil and in the world. It affects half a million women with a death rate of 50%. The visual, alternative methods to cytology, considered viable for developing countries, are being assessed more intensively in the last decade. Objective: To evaluate the performance of Cervical Digital Photography (CDP) in detecting cervical cancer and its precursory lesions. Methods: A total of 176 women were evaluated by the following methods: Visual Inspection with Acetic Acid (VIA), Visual Inspection with Lugol’s Iodine (VILI), Cervical Digital Photography with Acetic Acid (CDPA) and Cervical Digital Photography with Lugol’s Iodine (CDPL). Among these, 36 were classified by histology. Results: The correlation between evaluators observed Kappa values: Cervical Digital Photography with acetic acid, K = 0.441, and Cervical Digital Photography with Lugol's Iodine, K = 0.533. The correlation between the naked eye and cervical digital photography inspection after using acetic acid in the uterine cervix, K = 0.559, and the correlation after using Lugol's Iodine solution, K = 0.507, were regarded as moderate in both cases. Of the 36 patients with histological evaluation, 20 of the 25 positive cases were correctly assessed both by the CDPA as well as by CDPL, showing similar results than those described previously. Conclusion: CDP is considered a more promising method for screening the uterine cervix cancer and its precursory lesions in developing countries.
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Estudo de modelos das rea??es qu?micas no processo de combust?o in situTarifa, Jhon Mor?n 15 December 2014 (has links)
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Previous issue date: 2014-12-15 / A combust?o in situ (CIS) ? o m?todo de recupera??o t?rmico mais antigo. Este
m?todo consiste na queima parcial do ?leo in situ, cujo objetivo ? gerar uma frente de
combust?o que ajude no movimento do ?leo. Essa frente de combust?o aquece as zonas
pr?ximas, logrando a redu??o da viscosidade do ?leo e permitindo o seu deslocamento at? o
po?o produtor. Apesar de parecer um processo f?cil, a combust?o in situ engloba uma s?rie de
mecanismos complexos que mesmo na atualidade a torna dif?cil de representar atrav?s de
modelos anal?ticos, f?sicos e de simula??o num?rica. O objetivo do trabalho ? analisar e
determinar os par?metros que t?m influ?ncia no processo, destacando a cin?tica (energia de
ativa??o, coeficiente de Arrhenius e porcentagem de craqueamento para a produ??o de coque
durante o processo) de tr?s diferentes modelos de rea??es qu?micas e da vaz?o de inje??o do
ar. Para verificar a aplicabilidade do processo no Brasil foi realizado um estudo de simula??o
em reservat?rios de ?leo pesado com caracter?sticas do Nordeste Brasileiro. As simula??es
foram realizadas utilizando o m?dulo ?STARS? da ?Computer Modelling Group?, com o
objetivo de realizar estudos de m?todos de recupera??o avan?ada de ?leo. Dentre todos os
par?metros analisados, a energia de ativa??o-fator pr?-exponencial apresentou a maior
influ?ncia, ou seja, quanto menor o valor da energia de ativa??o-fator pr?-exponencial maior a
fra??o de ?leo recuperada. A porcentagem de craqueamento mostrou uma forte influ?ncia no
processo, devido a que enquanto menor for a quantidade de coque formado maior ? volume de
?leo recuperado. / In situ Combustion (CIS) is the oldest thermal method of oil recovery. This method
consists of partial combustion of in situ oil, its goal is to generate a combustion front that
helps to move the oil. This combustion front will heat the surrounding areas, achieving a
reduction in oil viscosity and allowing its displacement into the production well. It may seem
a simple process, however in situ combustion involves a series of complex mechanisms that
difficult until today its representation through analytical models, physical models and
numerical simulation. The aim of this investigation is to analyze and determine the parameters
that influence the process, highlighting the kinetics of the process (activation energy,
Arrhenius coefficient and percentage of cracking for the production of coke) three different
models of chemical reactions and the air injection rate. To verify the applicability of the
process in Brazil a simulation study was conducted in heavy oil reservoirs with characteristics
of the Brazilian Northeast. The simulations were performed using the "STARS" module from
the "Computer Modelling Group", which objective is to study methods of enhanced oil
recovery. Among all the analyzed parameters, the activation energy-pre-exponential factor
showed the greatest influence, that is, the lower the value of the activation energy-preexponential
factor the higher the fraction of oil recovery. The cracking percentage also
showed a strong influence in the process, the smaller the amount of coke formed the larger
volume of oil recovery.
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Avalia??o do desempenho da paligorsquita modificada e do carv?o da pir?lise do lodo de esgoto no processo de degrada??o fotocatal?tica do fenol / Performance assessment of modified palygorskite and pyrolysis char of sewage sludge as catalysts on the degradation of phenol in a photocatalytic reactorMedeiros, Emerson Alencar de 02 October 2015 (has links)
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Previous issue date: 2015-10-02 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / ? preocupante o descontrole por parte das ind?strias que produzem insumos relacionados aos compostos fen?licos, promovendo a emiss?o ou descarte desse poluente no meio ambiente, trazendo danos irrevers?veis ? natureza bem como ao ser humano. Diante disso, ? imprescind?vel a realiza??o de um tratamento desses efluentes antes de serem descartados no meio ambiente, reduzindo a concentra??o do contaminante ? valores determinados pela legisla??o. Procura-se, portanto, o tratamento desses efluentes utilizando novos materiais catal?ticos que viabilizem o processo como um todo. Nesse contexto, o presente trabalho tem como objetivo o tratamento, caracteriza??o e avalia??o de novos catalisadores na rea??o de degrada??o fotocatal?tica do fenol. Os ensaios foram realizados em um reator fotocatal?tico, em condi??es constantes de temperatura (50 ?C), pot?ncia da l?mpada (400 W), volume da fase l?quida (3,4 L), concentra??o do catalisador (1 g L-1), concentra??o inicial do fenol (500 ppm) e tempo de rea??o 3 horas. Preliminarmente ? rea??o foi realizado um estudo com a vaz?o de oxig?nio (410, 515, 650 e 750 mL min-1) a fim de identificar o valor ?timo (650 ml min-1) a ser utilizado no processo de degrada??o do fenol. Os demais par?metros foram variados: pH do meio reacional (3, 5,5 e 10) e a natureza do catalisador (paligorsquita acidificada calcinada, paligorsquita impregnada com 3,8% de ferro e carv?o originado da pir?lise do lodo de esgoto dom?stico). Os materiais catal?ticos foram caracterizados por DRX, FRX, BET e distribui??o granulom?trica. No processo de degrada??o fotocatal?tica do fenol, os resultados mostraram que o pH tem influ?ncia significativa na convers?o do fenol, apresentando melhores resultados para o pH igual a 5,5. Os valores da convers?o do fenol variaram entre 58% (para a paligorsquita acidificada calcinada) e 52% para o carv?o do lodo de esgoto. As amostras l?quidas analisadas por cromatografia l?quida identificaram e quantificaram os seguintes produtos da degrada??o: hidroquinona, catecol e o ?cido mal?ico. Por fim, foi proposto um mecanismo do processo reacional, considerando que o fenol ? transformado em fase homog?nea e os demais reagem na superf?cie do catalisador. Para este ?ltimo, foi aplicado o modelo Langmuir-Hinshelwood, cujos balan?os de massas conduziram a um sistema de equa??es diferenciais que foram resolvidas utilizando o m?todo num?rico associado a uma minimiza??o da fun??o objetivo para obten??o e otimiza??o dos par?metros cin?ticos e de adsor??o. O modelo se ajustou satisfatoriamente aos resultados experimentais. A partir do mecanismo proposto e com as condi??es operat?rias utilizadas no presente trabalho, a etapa mais favorecida, independente do catalisador, foi a do grupo ?cidos (originada dos compostos quin?nicos), sendo transformado em CO2 e ?gua, cuja constante de velocidade k4 apresentou valor 0,578 mol L-1 min-1 para a paligorsquita acidificada calcinada, 0,472 mol L-1 min-1 para o Fe2O3/paligorsquita e 1,276 mol L-1 min-1 para o carv?o do lodo, sendo este ?ltimo o melhor catalisador para mineraliza??o dos ?cidos em CO2 e ?gua. Os quin?nicos foram mais fortemente adsorvidos nos s?tios dos catalisadores paligorsquita acidificada calcinada e Fe2O3/paligorsquita, cujas constantes de adsor??o foram semelhantes (~4,45 L mol-1) e superior ao carv?o do lodo (3,77 L mol-1). / The uncontrolled disposal of wastewaters containing phenolic compounds by the industry has caused irreversible damage to the environment. Because of this, it is now mandatory to develop new methods to treat these effluents before they are disposed of. One of the most promising and low cost approaches is the degradation of phenolic compounds via photocatalysis. This work, in particular, has as the main goal, the customization of a bench scale photoreactor and the preparation of catalysts via utilization of char originated from the fast pyrolysis of sewage sludge. The experiments were carried out at constant temperature (50?C) under oxygen (410, 515, 650 and 750 ml min-1). The reaction took place in the liquid phase (3.4 liters), where the catalyst concentration was 1g L-1 and the initial concentration of phenol was 500 mg L-1 and the reaction time was set to 3 hours. A 400 W lamp was adapted to the reactor. The flow of oxygen was optimized to 650 ml min-1. The pH of the liquid and the nature of the catalyst (acidified and calcined palygorskite, palygorskite impregnated with 3.8% Fe and the pyrolysis char) were investigated. The catalytic materials were characterized by XRD, XRF, and BET. In the process of photocatalytic degradation of phenol, the results showed that the pH has a significant influence on the phenol conversion, with best results for pH equal to 5.5. The phenol conversion ranged from 51.78% for the char sewage sludge to 58.02% (for palygorskite acidified calcined). Liquid samples analyzed by liquid chromatography and the following compounds were identified: hydroquinone, catechol and maleic acid. A mechanism of the reaction was proposed, whereas the phenol is transformed into the homogeneous phase and the others react on the catalyst surface. For the latter, the Langmuir-Hinshelwood model was applied, whose mass balances led to a system of differential equations and these were solved using numerical methods in order to get estimates for the kinetic and adsorption parameters. The model was adjusted satisfactorily to the experimental results. From the proposed mechanism and the operating conditions used in this study, the most favored step, regardless of the catalyst, was the acid group (originated from quinone compounds), being transformed into CO2 and water, whose rate constant k4 presented value of 0.578 mol L-1 min-1 for acidified calcined palygorskite, 0.472 mol L-1 min-1 for Fe2O3/palygorskite and 1.276 mol L-1 min-1 for the sludge to char, the latter being the best catalyst for mineralization of acid to CO2 and water. The quinones were adsorbed to the acidic sites of the calcined palygorskite and Fe2O3/palygorskite whose adsorption constants were similar (~ 4.45 L mol-1) and higher than that of the sewage sludge char (3.77 L mol-1).
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Montagem e opera??o de um secador pneum?tico tipo flashFreire, Luziany Adyja da Costa 08 July 2011 (has links)
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Previous issue date: 2011-07-08 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / In this work, a pneumatic dryer has been designed and assembled in laboratory scale
in order to study and evaluate configurations more efficient for application in drying of
important materials of Northeast region in Brazil. The equipment was tested with drying of
corn and rice grains, in conditions of temperature and air velocity at 80 oC and 35 m/s,
respectively. For this type of dryer, it is recommended to work at temperatures above 200 ?C and air velocity with higher dynamic pressure. However, even under operating conditions below what it is recommended, the results obtained with the pneumatic dryer were satisfactory. In addition, experiments of drying were performed by using a cabinet dryer (batch dryer) under the same conditions used in the pneumatic dryer. Flash one curves for the corn were fitted satisfactorily by applying of the Lewis model, while a better agreement was
found for rice by using the Page model. The data obtained with both drying processes allowed to compare the performance between pneumatic and batch dryers. In respect to drying rate,
the pneumatic dryer presented a similar performance to the batch dryer during processing with corn and a superior performance to the last one during processing with rice. Therefore, it was possible to verify that the pneumatic dryer assembled in this preliminar study can be applied
for different materials and under different operating conditions / Este trabalho tem como objetivo principal ? concep??o, montagem e opera??o de um secador pneum?tico do tipo flash com o prop?sito de avaliar novas configura??es de
secadores, apresentando uma import?ncia regional no contexto da produ??o agr?cola de gr?os. O equipamento operou com temperaturas na ordem de 80?C e velocidade do ar de secagem
igual a 35 m/s. Para este tipo de secador recomenda-se temperaturas superiores a 200?C e velocidades com alta press?o din?mica. O equipamento operou com um bom desempenho na secagem do milho e arroz. Para efeito comparativo, tamb?m foi utilizado um secador de bandejas para secagem do milho e do arroz com casca em condi??es operacionais similares as praticadas com secador pneum?tico do tipo flash. Os resultados experimentais demonstraram que na secagem do milho ambos secadores responderam com desempenho an?logo no que ser refere ? taxa de secagem. J? na secagem do arroz com casca, o secador pneum?tico apresentou um desempenho superior ao secador de bandejas. Portanto, a partir dos dados experimentais as curvas para a secagem do milho foram melhor correlacionadas com o modelo de Lewis, enquanto que as curvas de secagem do arroz com casca foram melhor ajustadas com o modelo
de Page. Assim, pode-se concluir que a configura??o montada apresenta aspectos promissores que podem ser estudados utilizando-se materiais com diferentes caracter?sticas e em diferentescondi??es operacionais
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Prepara??o de poliuretana ? base de ?leo de mamonaRodrigues, Juc?lia Maria Emerenciano 15 December 2005 (has links)
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Previous issue date: 2005-12-15 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Polyurethanes are very versatile macromolecular materials that can be used in the form of powders, adhesives and elastomers. As a consequence, they constitute important subject for research as well as outstanding materials used in several manufacturing processes. In addition to the search for new polyurethanes, the kinetics control during its preparation is a very important topic, mainly if the polyurethane is obtained via bulk polymerization. The work in thesis was directed towards this subject, particularly the synthesis of polyurethanes based castor oil and isophorone diisocianate. As a first step castor oil characterized using the following analytical methods: iodine index, saponification index, refraction index, humidity content and infrared absorption spectroscopy (FTIR). As a second step, test specimens of these polyurethanes were obtained via bulk polymerization and were submitted to swelling experiments with different solvents. From these experiments, the Hildebrand parameter was determined for this material. Finally, bulk polymerization was carried out in a differential scanning calorimetry (DSC) equipment, using different heating rates, at two conditions: without catalyst and with dibutyltin dilaurate (DBTDL) as catalyst. The DSC curves were adjusted to a kinetic model, using the isoconversional method, indicating the autocatalytic effect characteristic of this class of polymerization reaction / Poliuretanas s?o pol?meros de grande versatilidade, podendo ser usadas na forma de p?s, adesivos ou elast?meros. Por este motivo, as poliuretanas s?o amplamente pesquisadas e utilizadas nas ind?strias. Paralelamente ? busca por novas poliuretanas, ? importante o controle cin?tico durante sua obten??o, principalmente se estas s?o obtidas via polimeriza??o em massa. O trabalho desta tese aborda este problema, especificamente no caso da obten??o de poliuretanas derivadas do ?leo de mamona e diisocianato de isoforona. Para isto, primeiramente o ?leo de mamona foi caracterizado atrav?s dos seguintes m?todos anal?ticos: ?ndice de iodo, ?ndice de saponifica??o, ?ndice de refra??o, ?ndice de hidroxila, teor de umidade e espectroscopia de absor??o na regi?o do infravermelho (FTIR). Como segundo passo, os corpos de prova dessas poliuretanas foram obtidos atrav?s de polimeriza??o em massa e submetidos a ensaios de inchamento com diferentes solventes. A partir destes ensaios o par?metro de Hildebrand foi determinado para este material. Finalmente, a polimeriza??o em massa desse material foi executada em equipamento de calorimetria explorat?ria diferencial (DSC) a diferentes taxas de aquecimento sob duas condi??es: sem catalisador e com o catalisador, dibutil-dilaurato de estanho (DBTDL). As curvas de DSC foram ajustadas a modelos cin?ticos, usando o m?todo isoconversional, caracterizando o car?ter autocatal?tico da forma??o de poliuretanas
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Estudo da produ??o de biossurfactantes sintetizados por Pseudomonas aeruginosa AP029-GVIIA utilizando manipueira como fonte de carbonoBezerra, M?rcio Silva 11 June 2012 (has links)
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Previous issue date: 2012-06-11 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / This study evaluates the biosurfactants production from cassava wastewater, an agro industrial residue, to be used as carbon source. Using a factorial design 24-1 (half fraction), 10 tests were performed using Pseudomonas aeruginosa AP029/GVII-A in submerged batch cultivation in rotating incubator (shaker). The influence of factors (temperature, agitation, aeration ratio and concentration of cultivation medium) at two different levels for the synthesis of the biosurfactant. Samples were collected throughout the cultivation by 132 hours of fermentation were completed. The best outcome was intended by following production through substrate consumption, dry matter, reduction of surface tension (ring method) and emulsification index. The kinetics of microorganism was assessed for the carbon source used. The results showed that the cassava wastewater is a well assimilable substrate for the production of biotensoactive, reaching 91 % of consumption by the micro-organism under study. The growth temperature was found to be one of the leading factors in the synthesis of the metabolite, followed by aeration and also due to the agitation. The best results showed a 30 % reduction in surface tension (% RTS) for the environment, reaching values of 30 mN/m; 3.0 g /L of biomass and emulsifying index greater than 65 %. The metabolite synthesized still remained stable for different salt concentrations (1, 5 and 10 % w/ v) and alkaline pH (8-10). / O presente trabalho avalia a produ??o de biossurfactantes a partir de manipueira, um res?duo agroindustrial a ser utilizado como fonte de carbono. Empregando um planejamento fatorial 24-1 (fra??o meia), 10 ensaios foram realizados utilizando Pseudomonas aeruginosa AP029-GVIIA em cultivo descont?nuo submerso em incubador rotat?rio (shaker). Foi analisada a influ?ncia dos fatores (temperatura, agita??o, raz?o de aera??o e concentra??o do substrato) em dois diferentes n?veis para a s?ntese do biossurfactante. Amostras foram coletadas em intervalos regulares durante o cultivo at? 132 horas de fermenta??o. Buscou-se o melhor resultado acompanhando a produ??o atrav?s do consumo de substrato, massa seca, redu??o da tens?o superficial (m?todo do anel) e ?ndice de emulsifica??o. O comportamento cin?tico do micro-organismo foi avaliado para a fonte de carbono utilizada. Os resultados mostraram que a manipueira ? bastante assimil?vel e potencial substrato na produ??o do biotensoativo, onde se observou 91% de consumo pelo micro-organismo em estudo. A temperatura de cultivo revelou ser um dos fatores preponderantes na s?ntese do metab?lito, acompanhada pela raz?o de aera??o e agita??o. Os melhores resultados mostraram redu??o de 30% da tens?o superficial (%RTS) em rela??o ao meio inicial, alcan?ando valores de 31 mN/m; 3,0 g/L de biomassa e ?ndice de emulsifica??o superior a 65%. O metab?lito sintetizado ainda se mostrou est?vel para diferentes concentra??es salinas (1, 5 e 10% m/v) e pH alcalino (8-10).
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Teoria cin?tica n?o extensiva: efeitos f?sicos em gases e plasmasSilva Junior, Raimundo 02 June 2000 (has links)
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Previous issue date: 2000-06-02 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The standard kinetic theory for a nonrelativistic diluted gas is
generalized in the spirit of the nonextensive statistic distribution
introduced by Tsallis. The new formalism depends on an arbitrary q
parameter measuring the degree of nonextensivity. In the limit q = 1, the
extensive Maxwell-Boltzmann theory is recovered.
Starting from a purely kinetic deduction of the velocity q-distribution
function, the Boltzmann H-teorem is generalized for including the
possibility of nonextensive out of equilibrium effects. Based on this
investigation, it is proved that Tsallis' distribution is the necessary
and sufficient condition defining a thermodynamic equilibrium state in the
nonextensive context. This result follows naturally from the generalized
transport equation and also from the extended H-theorem.
Two physical applications of the nonextensive effects have been
considered. Closed analytic expressions were obtained for the Doppler
broadening of spectral lines from an excited gas, as well as, for the
dispersion relations describing the eletrostatic oscillations in a diluted
electronic plasma. In the later case, a comparison with the experimental
results strongly suggests a Tsallis distribution with the q parameter
smaller than unity.
A complementary study is related to the thermodynamic behavior of a
relativistic imperfect simple fluid. Using nonequilibrium thermodynamics,
we show how the basic primary variables, namely: the energy momentum
tensor, the particle and entropy fluxes depend on the several dissipative
processes present in the fluid. The temperature variation law for this
moving imperfect fluid is also obtained, and the Eckart and
Landau-Lifshitz formulations are recovered as particular cases / A teoria cin?tica padr?o para um g?s dilu?do n?o relativ?stico, ? generalizada no esp?rito da distribui??o estat?stica n?o-extensiva introduzida por Tsallis. O novo formalismo depende de um par?metro arbitr?rio q medindo o grau de n?o extensividade do sistema. No limite q = 1, a teoria extensiva de Maxwell-Boltzmann ? recuperada.
Iniciando com uma dedu??o puramente cin?tica da q-distribui??o de velocidades, o teorema-H de Boltzmann ? generalizado para incluir a possibilidade de efeitos n?o extensivos fora de equil?brio. Com base nesse estudo, demonstramos que a q-distribui??o de Tsallis ? uma condi??o necess?ria e suficiente para o equil?brio termodin?mico no regime n?o extensivo. Um resultado que segue naturalmente da equa??o de transporte generalizada e do novo teorema.
Duas aplica??es dos efeitos n?o-extensivos s?o consideradas. Express?es anal?ticas s?o obtidas para o q-alargamento Doppler das linhas espectrais de um g?s excitado e tamb?m para as rela??es de dispers?o descrevendo as oscila??es eletrost?ticas num plasma eletr?nico dilu?do. No segundo caso, uma compara??o com os resultados experimentais sugere fortemente uma distribui??o de Tsallis com par?metro q < 1.
Um estudo complementar est? relacionado com a termodin?mica de um fluido imperfeito relativ?stico. Utilizando a termodin?mica fora de equil?brio, n?s calculamos como as vari?veis prim?rias b?sicas: o tensor de energia-momento, o fluxo de part?culas e o de entropia dependem dos mais variados processos dissipativos. A taxa de varia??o da temperatura do fluido em movimento ? obtida, e as formula??es de Eckart e Landau-Lifshitz s?o recuperadas como casos particulares
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Microemuls?o contendo Crisina com potencial a??o antinociceptivaRamalho, ?zola Morais de Medeiros 22 February 2018 (has links)
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Previous issue date: 2018-02-22 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / A Crisina (5,7-Dihidroxiflavona) pertence ? classe flavona de flavonoides. ? encontrada naturalmente em mel, pr?polis, e v?rias esp?cies de plantas, incluindo esp?cies do g?nero Pelargonium, Passiflora e da fam?lia Pinaceae. A Crisina (CS) ? atualmente comercializada como suplemento diet?tico e, como outros flavonoides, tamb?m exibe diversos efeitos farmacol?gicos, dentre os quais est?o a atividade antinociceptiva e anti-inflamat?ria. Entretanto, sua efic?cia tem sido limitada devido ? sua baixa biodisponibilidade oral. As microemuls?es (ME) s?o sistemas de libera??o modificada definidos como sistemas termodinamicamente est?veis e isotropicamente transl?cidos de dois l?quidos imisc?veis, usualmente ?gua e ?leo, estabilizados por um filme interfacial de tensoativo, e quando necess?rio um cotensoativo. Estes sistemas possuem a capacidade de solubilizar compostos hidrof?bicos, melhorar absor??o, biodisponibilidade e estabilidade, incrementar a efic?cia e reduzir a toxicidade de f?rmacos incorporados. O objetivo deste trabalho foi a obten??o, caracteriza??o de um sistema microemulsionado para incorpora??o da CS e avalia??o da atividade antinociceptiva desse. A formula??o obtida atrav?s de um diagrama de fase tern?rio foi caracterizada f?sico-quimicamente quanto ao pH, condutividade e ?ndice de refra??o. Suas caracter?sticas estruturais e morfol?gicas foram analisadas atrav?s de espalhamento de luz din?mica (DLS) e microscopia de luz polarizada (MLP). Enquanto, a estabilidade da formula??o foi avaliada atrav?s dos estudos de estresse por centrifuga??o, aquecimento-resfriamento e congelamento-descongelamento. O perfil de libera??o in vitro foi determinado utilizando o modelo de c?lulas de Franz. A avalia??o analg?sica foi realizada atrav?s de um teste comportamental que avalia o aumento do limiar de for?a sobre a pata dos camundongos para analisar o reflexo de retirada atrav?s de um analges?metro. Al?m da determina??o da capacidade de preven??o da forma??o de citocinas inflamat?rias avaliadas atrav?s de ELISA imunoensaio. Para isso foi administrada 30 minutos ap?s a indu??o por carragenina a dose de 25mg/kg de CS e MECS. A ME desenvolvida ? constitu?da por 5 % de miristato de isopropila, 55 % de ?gua e 40 % de LAS?, e apresentou pH compat?vel com a administra??o via oral, condutividade condizente com sistemas ?leo em ?gua, al?m de comportamento isotr?pico. A distribui??o de tamanho de got?culas foi do tipo monomodal e homog?neo, com tamanhos m?dios de got?culas de 170,7 ? 5,3 e 158,9 ? 26,7 nm, e potencial zeta negativo de -16,1 ? 1,9 e -10 ? 2,1, para formula??es com e sem CS, respectivamente. A ME mostrou-se est?vel frente aos estresses t?rmicos e por centrifuga??o. A libera??o in vitro da MECS obedeceu ao modelo cin?tico de ordem zero e preveniu a forma??o de citocinas inflamat?rias (redu??o de TNF ? e aumento de IL-10, p<0,01), al?m de apresentar atividade antinociceptiva no modelo de hiperalgesia induzida por carragenina (p<0,001). Portanto, p?de-se concluir que a veicula??o da CS atrav?s de um sistema microemulsionado mostrou-se como uma alternativa interessante para expandir o uso desse flavonoide como um f?rmaco no tratamento da dor inflamat?ria. / Chrysin (5,7-Dihydroxyflavone) belongs to the flavone class of flavonoids. It is found naturally in honey, propolis and various plant species, including species of the gender Pelargonium, Passiflora and the family Pinaceae. Chrysin (CS) is currently marketed as a dietary supplement and, like other flavonoids, also exhibits several pharmacological effects, among which are antinociceptive and anti-inflammatory activity. However, its efficacy has been limited because of its low oral bioavailability. Microemulsions (ME) are modified release systems defined as thermodynamically stable and isotropic translucent systems of two immiscible liquids, usually water and oil, stabilized by an interfacial surfactant film, and often a co-surfactant. ME systems have the ability to solubilize hydrophobic compounds, enhance absorption, bioavailability and stability, enhance efficacy, and reduce the toxicity of incorporated drugs. The aim of this work was the development, characterization and evaluation of the antinociceptive activity of a ME system containing CS. The formulation obtained through a ternary phase diagram was physic-chemically characterized for pH, conductivity and refractive index. Its structural and morphological characteristics were analyzed through dynamic light scattering (DLS) and polarized light microscopy (MLP). Meanwhile, the stability of the formulation was evaluated through centrifugal stress, heating-cooling and freeze-thaw studies. The in vitro release profile was determined using the Franz cell model. The analgesic evaluation was performed through a behavioral test that evaluates the increase of the force threshold on the paw of the mice to analyze the withdrawal reflex through an analgesimeter. In addition, it was determined the ability to prevent the formation of inflammatory cytokines evaluated by ELISA immunoassay. A dose of 25 mg/kg of CS and MECS was administered 30 minutes after carrageenan-induced inflammation. The developed ME consists of 5% isopropyl myristate, 55% water and 40% LAS?, and presented pH compatible with oral administration, conductivity consistent with oil-in-water systems, as well as isotropic behavior. The droplet size distribution was of the monomodal and homogeneous type, with mean droplet sizes of 170.7 ? 5.3 and 158.9 ? 26.7 nm, and negative zeta potential of -16.1 ? 1.9 and -10 ? 2.1, for formulations with and without CS, respectively. ME was stable during the thermal stresses and centrifugation. The in vitro release of MECS followed the zero order kinetic model and prevented the formation of inflammatory cytokines (reduction of TNF? and increase of IL-10, p<0.01), as well as antinociceptive activity in carrageenan-induced inflammation model (p<0.001). Therefore, CS delivery through a microemulsion system proved to be an interesting alternative to expand the use of this flavonoid as a drug in the treatment of inflammatory pain.
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Evaluation de l'apport simultané des coutures sur la perméabilité des préformes cousues et sur les performances mécaniques des structures composites cousues / Simultaneous evaluation of the stitching seam on the permeability of stitched preforms and the mechanical performance of stitched composite structuresSong, Yang 22 December 2015 (has links)
Les matériaux composites 3D obtenus par couture ou piquage transverses présentent de nombreux atouts comparativement aux tissages interlocks ou orthogonaux 3D. Dans le but d’évaluer le potentiel de cette nouvelle génération de matériaux 3D, certaines études ont été consacrées à leur caractérisation mécanique. D’autres études se sont focalisées sur l’influence de certains types de coutures sur la perméabilité de matériaux cousus de type NCF (Non Crimp Fabrics). Cette thèse se propose d’étudier l’apport des coutures de type Tufting dans le renforcement transverse de tissus classiques 2D. Cet apport est évalué, conjointement, du point de vue mécanique et du point de vue de la perméabilité. Parmi les nombreux paramètres de couture, l’étude s’est focalisée sur l’influence de la densité de couture. A ce titre, trois différentes densités de coutures ont été réalisées, grâce à un robot de couture disponible au sein de notre laboratoire. Du point de vue de la perméabilité, les préformes cousues ont été réalisées avec des empilements identiques à ceux des préformes non cousues. L’évaluation des perméabilités a été conduite à travers un banc de mesure de perméabilité à flux unidirectionnel. Avec cette méthode, le tenseur de perméabilité plane est obtenu à travers trois mesures unidirectionnelles : 0° (chaine), 90° (trame) et 45°. L’analyse des résultats montre que la couture de type Tufting induit un effet atténuateur du rapport d’anisotropie K1/K2. D’autre part, il ressort que la position du fil de couture provoque des gradients de perméabilités locaux, très prononcés entre la surface et le cœur de la préforme. Pour les besoins de la caractérisation mécanique, six plaques composites ont été réalisées par le procédé RTM. Pour atteindre les caractéristiques mécaniques hors-plan, des plaques de 20 mm d’épaisseur, cousues et non cousues ont été réalisées. La CIN (Corrélation d’Image Numérique) a été utilisée pour cartographier les distributions des champs de déplacement lors des essais mécaniques (traction, compression sur cube et flexion en poutre courte), ceci afin de tenir compte de la présence des coutures au sein des matériaux. Les performances mécaniques évaluées se sont révélées bien en deçà des attentes, surtout en ce qui concerne les caractéristiques hors-plan. L’analyse micrographique des matériaux a révélé la présence de porosités concentrées au sein, ou dans le voisinage proche, des coutures. D’autre part, les coutures présentaient des courbures ou vrillages, provoquées par le compactage lors de la fermeture du moule RTM.En faisant le lien avec les résultats de perméabilité, il ressort que la présence des porosités au sein des coutures est une conséquence des gradients de perméabilité qui induisent des refermetures de flux d’imprégnation. / 3D composite materials, which obtained by stitching or tufting, have many advantages compared to the 3D orthogonal weaves or interlocks. ln order to evaluate the potential of this new generation of 3D materials, some studies have been devoted to their mechanical properties. Other studies have focused on the influence of certain types of seams on the permeability of materials such as NCF (Non Crimp Fabrics).This thesis is to study the contribution of seams through the thickness of reinforcement 2D classic fabrics. This contribution is evaluated the mechanical properties and their permeability at the same time. Among many stitching parameters, the study focused on the influence of the stitching density. Three different seams densities were carried out through a robot available in our laboratory.ln terms of permeability, the stitched preforms were laminated those of identical unstitched preforms by using Tufting.The evaluation of permeability was conducted in an unsaturated regime through a small scale bench test by the unidirectional flow. With this method, the in-plane permeability tensor is obtained through the measured permeability in three directions : 0° (warp), 90° (weft) and 45°. The results show that the type of Tufting seams reduces the effect of anisotropy ratio Kl/K2. And it is obvious that the position of the stitching thread causes local permeability gradients very pronouncedly between the heart and the surface of the preform. For the purposes of the mechanical properties, six composite plates were made by the RTM process. To achieve mechanical properties through the thickness of the plates of 20 mm thick, stitched and unstitched performed were prepared. DIC (Digital Image Correlation) was used to detect the distribution of displacement fields during mechanical testing (tensile, compression and short bearn bending) in order to take account of the presence of seams within materials. The measured mechanical performance proved below expectations, particularly with regard to the characteristics in the third direction. Micrographie analysis of materials revealed the presence of porosity concentrated within, or near the seams. Moreover, the bends or kinks of seams were caused by compaction during closure of the RTM mold. By connecting with the permeability data, it appears that the presence of porosities in the seams is a consequence ofpermeability gradients that induce impregnation flow reclosing.
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Développement d’un outil de Corrélation d’Images Numériques pour la caractérisation du comportement piézoélectrique et ferroélectrique / Developpement of a Digital Image Correlation tool for the characterisation of the piezoelectric and ferroelectric behaviourSegouin, Valentin 17 December 2018 (has links)
Les matériaux piézoélectriques et ferroélectriques présentent un comportementélectromécanique couplé. Cette particularité leur a permis d’être utilisés dans de nombreusesapplications telles que les applications de capteur, actionneur, transformateur et récupérateurd’énergie. En outre, en raison de leur comportement non linéaire et dissipatif, les matériauxferroélectriques sont de plus en plus utilisés dans le domaine de l’électronique en tant quecapacité accordable, mémoire non volatile, oscillateur et filtre. La performance et la fiabilitéde ces systèmes dépendent directement des propriétés ferroélectriques et piézoélectriques dumatériau, qui nécessite par conséquent d’être caractérisé. Les propriétés piézoélectriques,ferroélectriques, ferroélastiques et diélectriques des matériaux ferroélectriques ont été le sujetde nombreuses études. Pourtant, les conditions d’essai restent difficiles à maîtriser car lespropriétés thermiques, mécaniques et électriques de ces matériaux sont fortement couplées.Dans cette thèse, un dispositif de mesure de champ de déformation a été conçu pourcaractériser le comportement piézoélectrique et ferroélectrique des céramiquesferroélectriques. Ce dispositif utilise un banc optique ainsi qu’un algorithme de Corrélationd’Images Numériques (CIN) 2D appelé CorreliRT3. Cet algorithme est basé sur une approcheglobale et réduit les erreurs de mesure de déplacement en s’appuyant sur les équationsd’équilibre de la mécanique des solides. Grâce au banc de caractérisation par CIN, il estmontré que les déformations piézoélectriques et ferroélectriques peuvent être mesurées avecune incertitude d’environ 10-5. Cette incertitude est atteinte aussi bien pour des sollicitationssimples que couplées (champ électrique et/ou contrainte mécanique). Il est aussi montré quele banc expérimental permet de vérifier les conditions d’essai en caractérisant l’hétérogénéitédes déformations lors d’un essai matériau.Dans les deux derniers chapitres, un matériau ferroélectrique est caractérisé souschamp électrique et sous contrainte mécanique. Le comportement du matériau est présenté etdiscuté dans les différentes configurations de chargement. Les propriétés matériau, telles queles coefficients piézoélectriques (d33, d31), sont extraites et étudiées en fonction du champélectrique et de la contrainte. Les résultats montrent que la CIN est capable de mesurer etcaractériser le comportement et les propriétés des matériaux ferroélectriques etpiézoélectriques. L’avantage de la CIN étant que, contrairement aux méthodes de mesureclassiques, celle-ci ne perturbe pas les conditions d’essai (mesure sans contact) et permette dedétecter la présence d’erreurs systématiques. / Piezoelectric and ferroelectric materials exhibit a coupled electromechanicalbehaviour. This property allows a use in various kinds of applications such as sensors,actuators, harvesting devices or converters. In addition, due to their non-linear and dissipativebehaviour, ferroelectric materials are increasingly used in electronic applications such astunable capacitors, non-volatile memory, oscillators and filters. The performance andreliability of such devices depend on the material electromechanical properties, whichconsequently need to be characterised. In the past decades, such characterisation was largelydeveloped and the piezoelectric, ferroelectric, ferroelastic and dielectric properties offerroelectrics were the subject of numerous studies. Yet the test conditions are difficult tocontrol due to the strong interplay between thermal, mechanical and dielectric properties.In this work, a full-field measurement apparatus has been designed to characterise thepiezoelectric and ferroelectric strain behaviour of ferroelectric ceramics. This apparatus usesan optical setup and a 2D Digital Image Correlation (DIC) algorithm named CorreliRT3. Thealgorithm is based on a global approach and reduces the displacement field errors using thebalance equations of solid mechanics. It is shown that piezoelectric and ferroelectric strainscan be measured with an uncertainty around 10-5 by using the developed setup. Thisuncertainty is reached under uncoupled or coupled loading (electric field and/or stress). It isalso shown that the experimental setup can control the test conditions by characterising thestrain heterogeneity during the test.In the two last chapters, a ferroelectric material is characterised under electric field andstress. The material behaviour is presented and discussed in the different loadingconfigurations. Material properties, such as the longitudinal and transverse piezoelectriccoefficients (d33, d31) are extracted and analysed as a function of the electric field and stress.The results show that the DIC technique is able to measure and characterise the behaviour andthe properties of ferroelectric and piezoelectric materials. The main benefits of this techniqueis that, contrary to classical measurement techniques, the measurement does not alter the testconditions. Moreover, DIC is able to detect test anomalies such as strain heterogeneities
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