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Tratamento termoqu?mico do tit?nio auxiliado por plasma de ar - N2 - O2Braz, Danilo Cavalcante 09 June 2011 (has links)
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Previous issue date: 2011-06-09 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Discs were grade II cp Ti oxynitride by plasma of Ar - N2 - O2 using
different proportions of individual gases. These ratios were established from
analysis of optical emission spectroscopy (OES) of plasma species. The
proportions that resulted in species whose spectra showed an abrupt change of
light intensity were chosen for this study. Nanohardness tests revealed that
there was a correlation between the intensity of N2
+ species with the hardness,
because the treatments where they had a higher intensity, obtained a higher
value nanohardness, although the crystalline phases have remained
unchanged. With respect to topography, it was observed that in general, the
surface roughness is related to the intensities of plasma species, because they
may have different values depending on the behavior of the species. Images
obtained by optical microscopy revealed a surface with grains of different colors
to optical reflectance showed a peak of reflection in the red area. Measures the
contact angle and surface tension showed hydrophilic properties and
hydrophilic with little variation of polar and dispersive components of surface
tension / Discos de tit?nio cp grau II foram oxinitretados por plasma de Ar - N2 - O2
usando diferentes propor??es de gases individuais. Essas propor??es foram
estabelecidas a partir de an?lises de espectroscopia de emiss?o ?ptica (OES)
das esp?cies do plasma. As propor??es que resultaram em espectros cujas
esp?cies apresentaram varia??o abrupta de intensidade luminosa foram
escolhidas para o presente trabalho. Os ensaios de nanodureza revelaram que
houve uma rela??o entre a intensidade da esp?cie N2
+ com a dureza, pois para
os tratamentos onde estas apresentaram maior intensidade, obteve-se maior
valor de nanodureza, embora as fases cristalinas tenham se mantido
inalteradas. Com rela??o ?s topografias, observou-se que de um modo geral, a
rugosidade superficial est? relacionada com as intensidades das esp?cies do
plasma, pois estas podem apresentar valores diferentes dependendo do
comportamento das esp?cies. Imagens obtidas por microscopia ?ptica
revelaram uma superf?cie com gr?os de diferentes cores e a reflet?ncia ?ptica
mostrou um pico m?ximo de reflex?o na regi?o do vermelho. As medidas de
?ngulo de contato e tens?o mostraram superf?cies com propriedades
hidrof?licas e pouco hidrof?licas com varia??o das componentes polar e
dispersiva da tens?o superficial
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Tratamento t?rmico do tit?nio e suas consequ?ncias sobre as propriedades f?sico-qu?micas e de biocompatibilidadeMacedo, Haroldo Reis Alves de 03 February 2012 (has links)
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Previous issue date: 2012-02-03 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The titanium and titanium alloys are widely used as biomaterial in biomedical device and so research have been developed aiming to improve and/or better to understand interaction biomaterial/biological environment. The process for manufacturing of this titanium implants usually involves a series of thermal and mechanical processes which have consequence on the final product. The heat treatments are usually used to obtain different properties for each application. In order to understand the influence of these treatments on the biological response of the surface, it was done, in this work, different heat treatments in titanium and analyzed their influence on the morphology, adhesion and proliferation of the pre-osteoblastic cells (MC3T3-E1). For such heat-treated titanium disks were characterized by optical microscopy, contact angle, surface energy, roughness, microhardness, X-ray diffraction and scanning through the techniques (BSE, EDS and EBSD). For the analysis of biological response were tested by MTT proliferation, adhesion by crystal violet and β1 integrin expression by flow cytometry. It was found that the presence of a microstructure very orderly, defined by a chemical attack, cells tend to stretch in the same direction of orientation of the material microstructure. When this order does not happen, the most important factor influencing cell proliferation is the residual stress, indicated by the hardness of the material. This way the disks with the highest level state of residual stress also showed increased cell proliferation / O tit?nio e suas ligas s?o amplamente utilizados como biomaterial em dispositivos biom?dicos e devido a isso pesquisas t?m sido desenvolvidas visando aperfei?oar e/ou compreender melhor a intera??o biomaterial/meio biol?gico. O processo de fabrica??o desses dispositivos de tit?nio geralmente envolve uma s?rie de processos t?rmicos e mec?nicos e que t?m consequ?ncias no produto final. Os tratamentos t?rmicos s?o usualmente utilizados para obten??o de propriedades diferenciadas para cada aplica??o. Com o intuito de entender a influ?ncia desses tratamentos sobre a resposta biol?gica da superf?cie, foram realizados, no presente trabalho, diferentes tratamentos t?rmicos em tit?nio e analisadas suas influ?ncias na morfologia, ades?o e prolifera??o de c?lulas pr?-osteobl?stica (MC3T3-E1). Para tanto os discos de tit?nio tratados termicamente foram caracterizados por microscopia ?tica, ?ngulo de contato, energia de superf?cie, rugosidade, microdureza Vickers, difra??o de raios-X e microscopia eletr?nica de varredura atrav?s das t?cnicas de EBS, EDS e EBSD. Para an?lise da resposta biol?gica foram realizados teste de prolifera??o por MTT, ades?o por cristal violeta e express?o da integrina β1 por citometria de fluxo. Foi verificado que na presen?a de uma microestrutura muito ordenada, definida atrav?s de um ataque qu?mico, as c?lulas tendem a se alongar no mesmo sentido da orienta??o microestrutural do material. Quando essa ordem n?o acontece, o fator mais importante a influenciar na prolifera??o celular ? a tens?o residual, indicada pela dureza do material. Deste modo os discos que apresentaram maior estado de tens?o residual apresentaram tamb?m maior prolifera??o celular
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S?ntese, caracteriza??o de ?xido de alum?nio a partir de esferas h?bridase aplica??o na convers?o do glicerol: influ?ncia do grau de substitui??o e polimeriza??o da carboximetilceluloseSilva, Monickarla Teixeira Pegado da 23 February 2016 (has links)
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Previous issue date: 2016-02-23 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Suportes catal?ticos ? base de ?xido de alum?nio foram sintetizados pelo m?todo e esferas h?bridas utilizando carboximetilcelulose (CMC) como precursor org?nico (template) e nitrato de alum?nio como precursor inorg?nico. As caracteriza??es foram realizadas por an?lises de termogravimetria (TG), difra??o de raios-X (DRX), espectroscopia no infravermelho por transformada de fourier (FTIR), microscopia eletr?nica de varredura (MEV) e fisissor??o N2. Os materiais sintetizados foram testados na rea??o de convers?o do glicerol em fase g?s. Os estudos da s?ntese indicaram que as caracter?sticas do biopol?mero (grau de substitui??o e de polimeriza??o) influenciam diretamente no valor m?ximo da rela??o entre o precursor org?nico e inorg?nico para a forma??o das esferas h?bridas. As propriedades f?sico-qu?micas do material final (cristalinidade, porosidade, ?rea espec?fica e morfologia) mostraram uma depend?ncia direta com as propriedades do biopol?mero (grau de substitui??o e de polimeriza??o), indicando a versatilidade desta rota s?ntese. Os espectros de FTIR confirmaram a forma??o de um material h?brido quando se compara o espectro da CMC pura com os s?lidos obtidos ap?s a secagem. Os resultados de DRX mostraram um perfil de material amorfo para algumas amostras. Para alguns s?lidos foi poss?vel identificar a forma??o de uma fase cristalina relacionada com a alumina hidratada, ?xido de alum?nio e ?xido de cobre. As imagens obtidas por MEV indicaram a forma??o de um material com morfologia semelhante a uma esponja ap?s a calcina??o, caracter?stico de um s?lido altamente poroso. O perfil de adsor??o/dessor??o de N2 confirma a forma??o de materiais contendo micro-mesoporos com uma ?rea espec?fica entre 50-162 m2.g-1 para os suportes e 112-303 m2.g-1 para os catalisadores com cobre, indicando um aumento ?rea ap?s a adi??o do Cu por impregna??o devido a redissolu??o e recristaliza??o da fase alumina. Testes catal?ticos indicaram que os ?xidos s?o ativos e seletivos para a convers?o do glicerol (92-15%) a bioprodutos de alto maior valor agregado, confirmando a viabilidade do m?todo de s?ntese. / Catalytic supports based on aluminum oxide were synthesized by the method of hybrid
spheres using carboxymethylcellulose (CMC) as organic precursor (template) and
aluminum nitrate as inorganic precursor. The characterizations were performed by
thermal chemical analysis (TGA), X-Ray diffraction (XRD), fourier transform infrared
(FTIR) spectroscopy, scanning electron microscopy (SEM) and N2 physisorption. The
study of synthesis indicated that the characteristics of the biopolymer (degree of
substitution and polymerization) directly influence on the maximum value of the ratio
between the organic and inorganic precursor for the formation of hybrid spheres. The
physicochemical properties of the final material (crystallinity, porosity, surface area
and morphology) showed a direct dependence on the biopolymer properties (degree of
substitution and polymerization), indicating the versatility of this synthesis route. The
FTIR spectra confirm the formation of a hybrid material when comparing the pure
CMC spectrum with the obtained solids after drying. The XRD results show a profile
of amorphous and crystalline material for the different samples. For some solids were
possible to identify the formation of a crystalline phase related to the hydrated
alumina, aluminium oxide and copper oxide. The images obtained by SEM analysis
showed the formation of a material with sponge-like morphology after calcination,
characteristic of highly porous solid. The N2 adsorption/desorption isotherm profile
confirms the formation of micro-mesoporous materials with a specific surface area
between 50-162 m2.g-1 for the supports and 112-303 m2.g-1 for the copper-based
catalysts, indicating an increase in the area after the addition of Cu by impregnation
due to redissolution and recrystallization of alumina phase. Catalytic tests were tested
in the glycerol conversion reaction (92-15%) to added value products in order to
confirm their real viability.
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Avalia??o da aptid?o cardiorrespirat?ria pelo Incremental Shuttle Walking Test em crian?as e adolescentes assintom?ticos do sexo masculinoGomes, Andreza Let?cia 10 November 2017 (has links)
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Previous issue date: 2018 / O Incremental Shuttle Walking Test (ISWT) vem sendo utilizado na avalia??o da aptid?o cardiorrespirat?ria (ACR) de crian?as e adolescentes com diferentes condi??es de sa?de. N?o se sabe se a resposta cardiorrespirat?ria apresentada por adolescentes saud?veis no ISWT ir? se assemelhar aquela induzida pelo teste de esfor?o cardiopulmonar (TECP). Os objetivos deste estudo foram: (1) Avaliar se o ISWT ? um teste m?ximo para adolescentes assintom?ticos do sexo masculino. (2) Propor uma equa??o matem?tica para predizer o pico do consumo de oxig?nio (VO2 pico) e, (3) testar a confiabilidade dessa equa??o para essa popula??o. M?todos: No primeiro est?gio do estudo, 26 participantes realizaram o ISWT e o TECP. No segundo est?gio 50 participantes realizaram o ISWT duas vezes. Em ambos os est?gios foram avaliados VO2 pico, a frequ?ncia card?aca m?xima (FC m?x.) e o pico da raz?o de troca respirat?ria (R pico). No terceiro est?gio foram comparados os valores do VO2 pico preditos pela equa??o criada e obtidos de forma direta no ISWT. Resultados: N?o houve diferen?a significativa no VO2 pico, R pico e FC m?x. obtidos no ISWT e TECP. Os valores encontrados para o VO2 pico (r = 0,44. p = 0,002) e R pico (r = -0,53, p< 0,01) obtidos no ISWT e TECP apresentaram correla??o moderada e significativa, al?m de concord?ncia na an?lise de Bland-Altman. A velocidade da marcha foi a vari?vel que explicou 48% (R2 = 0,48, p = 0,000) da varia??o no VO2 pico no ISWT. Foi criada a equa??o VO2 previsto = 5,490 + (17,093 x Velocidade da Marcha). Os resultados obtidos pela equa??o foram comparados com os valores obtidos pelo analisador de gases e nenhuma diferen?a significativa foi encontrada entre eles. Conclus?es: Em crian?as e adolescentes do sexo masculino o ISWT ? um teste de esfor?o m?ximo com repercuss?es cardiorrespirat?rias similares ao TECP. A equa??o preditiva proposta ? uma estimativa vi?vel para predi??o do VO2 pico para essa popula??o. / Disserta??o (Mestrado Profissional) ? Programa de P?s-Gradua??o em Reabilita??o e Desempenho Funcional, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2017. / The Incremental Shuttle Walking Test (ISWT) has been used to evaluate the Cardiorespiratory Fitness (CRF) of children and adolescents with different pathological conditions. It is unknown whether the cardiorespiratory response presented by asymptomatic adolescents in ISWT will be similar to that induced by CardiopulmonaryExerciseStress Test (CEPT). The aims of this study were: (1) To evaluate whether ISWT is a maximum test for asymptomatic male adolescents. (2) To propose a mathematical equation to predict peak oxygen consumption (VO2 peak) and (3) Totest the reliability of this equation on this population. Methods: In the first stage of the study, 26 participants performed the ISWT and the CEPT. In the second stage 33 participants performed the ISWT twice. In both stages, peak VO2, maximal heart rate (HR max) and peak respiratory rate (peak R) were evaluated. In the third stage, the peak VO2 values predicted by the equation created and obtained directly in the ISWT were compared. Results: There was no significant difference in the peak VO2 (p> 0.05), peak R (p> 0.05) and maximum HR obtained in ISWT and CEPT. The values found for the VO2 peak (r = 0.44, p = 0.002) and peak R (r = -0.53, p <0.01) obtained in the ISWT and CEPT presented a moderate correlation and anagreement in the analysis of Bland-Altman analysis. The gait speed was the variable that explained 48% (R2 = 0.48, p = 0.000) of the variation in the peak VO2. The VO2 peak equation = 5.490 + (17.093 x Gait Speed) was created. The results obtained by the equation were compared with the values obtained by the gas analyzer and no significant differences were found between them (p> 0.05). Conclusion: ISWT produced a cardiorespiratory response comparable to CEPT in asymptomatic male adolescents, and the developed equation presented viability to predict peak VO2 in adolescents.
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Caracteriza??o e efeitos da adi??o de vibra??o de todo o corpo aos exerc?cios de agachamento em idosos com osteoartrite de joelho.Avelar, N?bia Carelli Pereira de 13 August 2010 (has links)
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licenca_crative_commons.txt.txt: 53 bytes, checksum: 48f12eb36296e49e3babe2c05b2dc57e (MD5) / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (Capes) / Funda??o de Amparo ? Pesquisa do estado de Minas Gerais (FAPEMIG) / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / Quantificar o consumo de oxig?nio e a frequ?ncia card?aca durante a adi??o de vibra??o de todo o corpo aos exerc?cios de agachamento em idosos e investigar os efeitos do treinamento com exerc?cios de agachamento associados ? vibra??o de todo o corpo no desempenho funcional e no autorrelato do estado da osteoartrite de joelho em idosos foi o objetivo deste estudo. O consumo de oxig?nio e a frequ?ncia card?aca foram avaliados em repouso e durante os exerc?cios de agachamento com e sem vibra??o a 40 Hz de frequ?ncia e amplitude de 4 mm, de forma aleat?ria com intervalo m?nimo de 24 horas em 18 idosos (15 mulheres e 3 homens, com idade m?dia de 72+6 anos de idade). Para verificar os efeitos da adi??o de vibra??o de todo o corpo ao treinamento com exerc?cios de agachamento, 35 idosos com osteoartrite de joelho, com diagn?stico confirmado por exame cl?nico e radiogr?fico, foram avaliados em tr?s momentos distintos: tr?s semanas anteriores ao in?cio do programa, antes e imediatamente ap?s 12 semanas de interven??o. Os volunt?rios foram alocados aleatoriamente em tr?s grupos: um grupo de interven??o que realizou o programa de agachamento em associa??o com o est?mulo vibrat?rio, promovido pela plataforma vibrat?ria (GPV, N: 12), um grupo exerc?cio que realizou o mesmo programa de agachamento sem vibra??o (GE, N: 11) e um grupo controle que n?o realizou nenhum exerc?cio durante o per?odo do estudo (GC, N: 12). Todos os volunt?rios realizaram quatro testes de desempenho funcional, mensurados de forma direta (Escala de Equil?brio de Berg, Timed Get Up and Go, Teste de Levantar e Sentar na Cadeira e Teste de Caminhada de 6 Minutos), e avalia??o do autorrelato do estado da osteoartrite pelo Western Ont?rio McMaster Universities Osteoarthritis Index (WOMAC). A vibra??o de todo o corpo associada aos exerc?cios de agachamento promoveu um aumento adicional de cerca de 20 % no consumo de oxig?nio e de 7,5 % na frequ?ncia card?aca. Al?m disso, verificou-se que o programa proposto para o GPV aprimorou o desempenho em todos os testes funcionais e em todos os dom?nios do WOMAC. J? o GE apresentou melhora no autorrelato da dor (WOMAC) e aprimorou o desempenho apenas nos testes de Equil?brio de Berg e de Caminhada de 6 minutos. N?o houve mudan?a nos testes de desempenho funcional e nos dom?nios do WOMAC no grupo controle. Embora o est?mulo vibrat?rio tenha intensificado o consumo de oxig?nio e frequ?ncia card?aca durante os exerc?cios de agachamento, esse aumento pode ser insignificante do ponto de vista cl?nico. Al?m disso, a adi??o da vibra??o ao treino com exerc?cios de agachamento melhorou o desempenho funcional e o autorrelato do estado da doen?a em idosos com osteoartrite de joelhos. / Disserta??o (Mestrado) ? Programa Multic?ntrico de P?s-gradua??o em Ci?ncias Fisiol?gicas, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2010. / ABSTRACT
Quantify the oxygen consumption and heart rate when vibration is applied to whole body during squat exercises in elderly and investigate the effects of whole body vibration on the functional performance and self-reported disease status of elderly patients with knee osteoarthritis it was the objective this study. The oxygen consumption and heart rate were evaluated in 18 elderly individuals, 15 females and 3 males with a mean age of 72 ? 6 years, who were randomly submitted to 3 experimental situations. The measurements were taken during rest and during the performance of squatting exercises (8 series of 40 seconds with 40 seconds of rest between series; performing squats in 3-second cycles with 10-60 degrees of flexion) without or with vibration at a frequency of 40 Hz and amplitude of 4 mm. To verify the effects of the addition of the whole body vibration to the training with squatting exercises, 35 elderly with knee osteoarthritis, with diagnosis confirmed by clinical exams and radiographic, were evaluated at three different moments: three weeks before initiating training, immediately prior to training and immediately after 12 weeks of intervention, using four functional performance tests [the Berg Balance Scale (BBS), the Timed Get Up and Go Test (TGUG), the Chair Stand Test (CST) and the 6-Minute Walk Test (6MWT)] as well as a self-report from the patients on the status of their disease, assessed using the Western Ontario McMaster Universities Osteoarthritis Index (WOMAC). The participants were randomized into three groups: in the first group, patients performed squatting exercises on a vibrating platform over a 12-week period (vibration group; n=12); in the second group, patients performed squatting exercises without vibration over the same 12-week time period (exercise group; n=11); while the third group of patients were given no exercise training during the study (control group; n=12). Associating whole body vibration with squatting exercises resulted in an additional increase of 20% in oxygen consumption and 7.5% in heart rate in elderly. In addition, whole body vibration training associated with squatting exercises improved performance in all the functional tests and in all the domains of the WOMAC scale. In the exercise group, performance improved BBS and 6MWT and in the pain domain of the WOMAC scale. No change from baseline occurred in any of the tests performed on patients in the control group. Although the vibratory stimulus has increased oxygen consumption and heart rate during squatting exercises, this elicited increase may be insufficient to improve cardiovascular fitness. Moreover, vibration training associated with squatting exercises improved functional performance measured both directly and indirectly in elderly patients with knee osteoarthritis.
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Aprimoramento do processo de gera??o de oz?nio conduzido a partir da eletr?lise da ?gua pura / Improvement of the ozone generation process carried out from the electrolysis of the electrolyte-free waterSousa, Lindomar Gomes de 20 May 2013 (has links)
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Previous issue date: 2013-12-17 / Eletrodos constitu?dos de ?-PbO2 foram preparados via eletrodeposi??o, mediante inclus?o dos ?ons Fe3+ e F- na mistura precursora, usando como substratos tela de a?o (ASTM 316) e tecido de carbono, visando a produ??o eletroqu?mica de oz?nio (PEO) em um reator filtro-prensa conduzida na aus?ncia de eletr?lito l?quido. A an?lise das micrografias de MEV para ambos substratos revelaram que em baixas concentra??es dos dopantes houve a forma??o de gr?os bem definidos com uma ?rea superficial uniforme. A an?lise de Raios-X para ambos substratos revelou o desfavorecimento da forma??o da fase ?-PbO2 para a maioria da concentra??o dos dopantes. Estudos cronopotenciom?tricos evidenciaram a estabilidade dos anodos quando sujeitados a intensa evolu??o de gases. Para o eletrodo dopado com 1 mM do ?on Fe3+, a efici?ncia de corrente da PEO foram de 10% e 9,5% com uma velocidade de gera??o de oz?nio de 1,35 g h-1 e 1,40 g h-1 para os substratos de tela de a?o e de tecido de carbono, respectivamente. Os resultados encontrados s?o promissores indicando uma viabilidade do uso desses eletrodos para aplica??o no tratamento de ?gua, por isso, empregou-se o oz?nio produzido eletroquimicamente para tratar ?gua residu?ria proveniente da produ??o de biodiesel na planta piloto da UFVJM. O tratamento oxidativo da ?gua residu?ria foi conduzido num reator em coluna de bolhas via rea??o direta (oz?nio molecular), indireta (radical hidroxila) e mista (O3/HO?) manipulando-se o pH do meio reacional.A caracteriza??o do efluente ozonizado foi efetuada monitorando-se o processo de degrada??o da mat?ria org?nica dissolvida via espectrofotometria. A cin?tica do processo de degrada??o seguiu o modelo de pseudo-primeira ordem. Foi verificado que a constante cin?tica sofre varia??o com o tempo de ozoniza??o revelando, portanto, uma varia??o da recalcitr?ncia com o tempo de rea??o. A demanda de energia requerida no processo de ozoniza??o foi caracterizada por uma energia el?trica por ordem (EEO) de 139 kW h m-3 ordem-1. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Qu?mica, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2013. / ABSTRACT
Electrodes comprised of ?-PbO2 were prepared by electrodeposition, by moans of the inclusion of Fe3+ and F- ions in the precursor mixture, using as substrates steel screen (ASTM 316) and carbon cloth in order to produce ozone in an filter-press electrochemical reactor conducted in the absence of liquid electrolyte. The analysis of SEM micrographs revealed that for both substrates at low dopants concentrations resulted in the formation of well-defined grains with a uniform surface area. X-rays analysis for both substrates showed the inhibition of formation of the ?-PbO2 phase for most of the dopant concentration. Cronopotenciometric studies revealed a good stability of the anodes when they were subjected to the intense gas evolution. For the electrode doped with 1 mM Fe3+, the current efficiency of EOP were 10% and 9.5% for an ozone generation rate of 1.35 g h-1 and 1.40 g h -1 using the steel screen and carbon cloth substrates, respectively. These results are promising, indicating a feasibility of using these electrodes for application in water purification, so the electrochemical ozone produced was applied to treat residuary water obtained from the biodiesel produced in the pilot plant of UFVJM. The oxidative chemical treatment of wastewater was conducted in a bubble column reactor via direct (molecular ozone), indirect (hydroxyl radical) and mixed (O3/HO?) oxidation reaction thrush manipulating the pH of the reaction medium. The characterization of ozonated effluent was assessed by means of monitoring the degradation of the dissolved organic matter using spectrophotometry. The kinetics of the degradation process followed a pseudo-first order model. It was found that the rate constant changes on the ozonation time thus indicating a recalcitrance variation with the reaction time. The energy demand required in the ozonation process was described by an electric energy per order (EEO) of 139 kW h m-3 order-1.
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Avalia??o da produ??o de esp?cies reativas de oxig?nio e da citotoxicidade in vitro mediada pelo sistema 2,4-pentanodiona/horseradish peroxidase/oxig?nioPinheiro, N?thale Rodrigues 28 March 2014 (has links)
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Previous issue date: 2014 / Funda??o de Amparo ? Pesquisa do estado de Minas Gerais (FAPEMIG) / O sistema ADEPT (antibody-directed enzyme prodrug therapy) ? uma terapia antitumoral que envolve a ativa??o catal?tica de um pr?-f?rmaco, nas proximidades do s?tio tumoral, por uma enzima conjugada a um anticorpo monoclonal com afinidade para ant?genos espec?ficos das c?lulas tumorais. O sistema composto pela enzima Horseradish peroxidase (HRP) e ?cido indol-3-ac?tico (IAA) tem sido estudado para o emprego na terapia ADEPT, e associado ? indu??o de apoptose de c?lulas tumorais. A 2,4-pentanodiona (PD) tamb?m atua como substrato da HRP sendo oxidada por ela atrav?s de uma rea??o cuja cin?tica ? semelhante ? da cat?lise do IAA e, portanto, pode representar uma alternativa para essa terapia. Este trabalho teve como objetivo realizar uma avalia??o da citotoxicidade mediada pelos produtos provenientes da oxida??o da PD pela HRP frente a diferentes linhagens celulares, utilizando para isso diferentes metodologias que determinam a viabilidade celular como o azul de Trypan, MTT e vermelho neutro assim, como a an?lise microsc?pica das altera??es celulares induzidas por esses sistemas; estabelecer uma compara??o com a citotoxicidade mediada pela oxida??o do IAA catalisada pela mesma enzima; verificar a incid?ncia de morte celular por apoptose mediada pelos sistemas IAA/HRP/O2 e PD/HRP/O2; al?m de verificar a produ??o e os tipos de esp?cies reativas de oxig?nio (ERO) produzidas pelos dois sistemas. Os experimentos permitiram evidenciar que as combina??es PD/HRP/O2 e IAA/HRP/O2 levam a forma??o de ERO, sendo as esp?cies provavelmente formadas pela oxida??o da PD o radical ?nion super?xido e o per?xido de hidrog?nio (H2O2) e pela oxida??o do IAA o H2O2. Foi observado, somente para o IAA, um aumento na forma??o de ERO com o uso de uma maior concentra??o do substrato. Quanto ao estudo de viabilidade celular, esse permitiu evidenciar, atrav?s das tr?s metodologias, o efeito citot?xico dos sistemas PD/HRP/O2 e IAA/HRP/O2, no entanto, o ensaio do MTT mostrou-se mais sens?vel para esse estudo. A oxida??o do IAA pela HRP induziu apoptose, contudo n?o foi poss?vel identificar o tipo de morte celular mediada pelo sistema PD/HRP/O2, provavelmente devido a um problema t?cnico durante algumas an?lises em citometria de fluxo, o Quenhcing. Apesar de o sistema IAA/HRP/O2 ter apresentado uma destrui??o celular mais expressiva, o substrato IAA quando testado na aus?ncia da enzima mostrou-se
t?xico, o que n?o foi visto para a PD quando testada nas concentra??es de 1; 1,5 e 2 mM, o que a torna um bom substrato para o emprego na terapia ADEPT. / Disserta??o (Mestrado) ? Programa de P?s-gradua??o em Ci?ncias Farmac?uticas, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2014. / ABSTRACT
The system ADEPT (antibody-directed enzyme prodrug therapy) is an antitumor therapy that involves catalytic activation of a prodrug near the tumor site by an enzyme conjugated to a monoclonal antibody with affinity for specific antigens of tumor cells. The system composed by horseradish peroxidase (HRP) enzyme and indole-3-acetic acid (IAA) has been studied for the use in ADEPT therapy, and associated with apoptosis induction on tumor cells. The 2,4-pentanedione (PD) also acts as a substrate for HRP and being oxidized through a reaction whose kinetics is similar to the catalysis of IAA and, therefore, might represent an alternative to this therapy. This study aimed to conduct a evaluation of the cytotoxicity mediated by products from the oxidation of PD by HRP against different cell lines, using different methodologies that determine cell viability as Trypan blue, MTT and Neutral Red, as well as morphologic changes of the cell induced by these systems; establish a comparison with the cytotoxicity mediated by the oxidation of IAA catalyzed by the same enzyme; verify the incidence of apoptosis mediated by IAA/HRP/O2 and PD/HRP/O2 systems; besides verifying the production and types of reactive species oxygen (ROS) produced by the two systems. The experiments allowed to show that PD/HRP/O2 and IAA/HRP/O2 combinations lead to the formation of ROS, being the species probably formed by oxidation of PD the radical superoxide anion and hydrogen peroxide (H2O2) and by the oxidation of IAA the H2O2. It was observed only for the IAA, an increase in ROS production using a higher concentration of the substrate. Regarding the study of cell viability, this allowed to evidence, through the three methodologies, the cytotoxic effect of PD/HRP/O2 and IAA/HRP/O2 systems, however, the MTT assay proved more sensitive for this study. The oxidation of the IAA by HRP induced apoptosis, but could not identify the type of cell death mediated by PD/HRP/O2 system, The oxidation of by HRP the IAA induced apoptosis, but could not identify the type of cell death mediated by PD/HRP/O2 system, probably due to a technical problem for a few flow cytometric analyzes, the Quenching. Although IAA/HRP/O2 system have presented a more significant cell destruction, the IAA substrate when tested in the absence of enzyme was toxic, what has not seen for PD when tested in the concentrations of 1, 1.5, and 2 mM, making it a good substrate for employment in ADEPT therapy.
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Desenvolvimento de um dispositivo fotoeletroqu?mico a base de g-C3N4, Cu2O e CuO para clivagem da ?gua em H2 e O2Almeida, Monique Rocha 22 August 2016 (has links)
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Previous issue date: 2016 / Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM) / A convers?o de energia solar em energia qu?mica usando c?lulas fotoeletroqu?micas ? uma
estrat?gia interessante para armazenar energia. C?lulas fotoeletroqu?micas s?o dispositivos
constitu?dos de fotoeletrodos semicondutores que absorvem luz com energia maior ou igual a
energia de bandgap do semicondutor e geram cargas reativas (el?trons e buracos) na
superf?cie dos fotoeletrodos capazes de promover a redu??o e oxida??o da ?gua em H2 e O2,
respectivamente. Nesta disserta??o, quatro fotoeletrodos de g-C3N4, g-C3N4/Cu1%, g-
C3N4/Cu5% e Cu2O/CuO foram preparados com o objetivo de desenvolver uma c?lula
fotoeletroqu?mica para clivagem da ?gua em H2 e O2 de forma espont?nea. As medidas de
difratometria de raios X confirmaram a presen?a das fases g-C3N4 e Cu2O/CuO nos
fotoeletrodos. As imagens de MEV mostraram que os materiais ? base de g-C3N4 possuem
morfologia do tipo esponja, enquanto a heterojun??o Cu2O/CuO ? formada por nanopart?culas
de forma indefinida. Medidas de reflect?ncia difusa mostraram que o acoplamento do g-C3N4
e Cu2O/CuO resulta em uma melhora significativa na absor??o ?ptica dos fotoeletrodos.
Medidas de ?rea espec?fica indicaram que os nanomateriais ? base de g-C3N4 tem alta ?rea
superficial (?100 m2 g?1), enquanto a ?rea espec?fica da heterojun??o Cu2O/CuO foi de
17 m2 g?1. Os resultados de redu??o ? temperatura programada evidenciaram a forma??o das
heterojun??es. Os testes fotoeletroqu?micos de produ??o de O2 a partir da ?gua usando luz
vis?vel indicaram que em potenciais an?dicos, apenas o fotoanodo de g-C3N4 foi est?vel
apresentando uma densidade de fotocorrente de 16 ?A cm?2 que corresponde a uma efici?ncia
de convers?o de luz de 0,014%. Em potenciais cat?dicos, a maior densidade de fotocorrente
(60 ?A cm?2) foi obtida para o fotoeletrodo Cu2O/CuO. A efici?ncia de convers?o de luz do
fotocatodo de Cu2O/CuO foi de 0,029%. Com base nos dados obtidos, uma c?lula
fotoeletroqu?mica p-n foi constru?da usando a heterojun??o Cu2O/CuO como fotocatodo e g-
C3N4 como fotoanodo. Esta c?lula gerou uma densidade de fotocorrente in operando de
0,62 ?A cm?2 e uma fotovoltagem de 0,62 V. A efici?ncia de convers?o solar da fotoc?lula foi
de 0,004% sob irradia??o de luz vis?vel. Apesar da baixa efici?ncia obtida, espera-se que esta
disserta??o possa servir de inspira??o para o desenvolvimento de novos dispositivos
fotoeletroqu?micos para clivagem da ?gua em H2 e O2, usando luz vis?vel. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Qu?mica, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2016. / The conversion of solar energy into chemical energy using photoelectrochemical cells is an
interesting strategy to store energy. Photoelectrochemical cells are made up of semiconductor
photoelectrodes that absorb light with energy equal or higher than the bandgap energy of the
semiconductor to generate reactive charges (electrons and holes) on the surface of the
photoelectrodes, which can promote the oxidation and reduction reactions of water to form H2
and O2, respectively. In this dissertation, four photoelectrodes of g-C3N4, g-C3N4/Cu1%, g-
C3N4/Cu5%, and Cu2O/CuO were prepared in order to develop a photoelectrochemical cell
for spontaneous water splitting into H2 and O2. The X-ray diffraction patterns confirmed the
presence of g-C3N4 and Cu2O/CuO phases in the photoelectrodes. The SEM images showed
that the materials based on g-C3N4 have sponge-like morphology, whereas the Cu2O/CuO
heterojunction is formed by nanoparticles with undefined shapes. Diffuse reflectance
measurements showed that coupling g-C3N4 and Cu2O/CuO results in a significant
improvement in optical absorption of the photoelectrodes. Surface area measurements
indicated that the nanomaterials based on g-C3N4 have high surface areas (?100 m2 g?1), while
the specific area for the Cu2O/CuO heterojunction was 17 m2 g?1. The temperature
programmed reduction results evidenced the formation of the heterojunctions. The
photoelectrochemical assays of O2 production from water using visible light indicated that at
anodic potentials, only the photoanode g-C3N4 was stable showing a photocurrent density of
16 ?A cm?2, which corresponds to a light conversion efficiency of 0.014%. At cathodic
potentials, the higher photocurrent density (60 ?A cm?2) was obtained for the Cu2O/CuO
photoelectrode. The light conversion efficiency of the Cu2O/CuO photocathode was 0.029%.
Based on the obtained data, a p-n photoelectrochemical cell was constructed using the
Cu2O/CuO heterojunction as the photocathode and g-C3N4 as the photoanode. This photocell
generated a photocurrent density in operando of 0.62 ?A cm?2 and photovoltage of 0.62 V.
The light conversion efficiency of the photocell was 0.004% under visible light irradiation.
Despite the low efficiency obtained for the p-n photocell, it is expected that this dissertation
may serve of inspiration for the development of new photoelectrochemical devices for water
splitting into H2 and O2 using visible light.
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Reutiliza??o de im?veis de interesse patrimonial, voltados para a ahabita??o: um estudo de caso na Ribeira-Natal/RNCosta, Gilmar de Siqueira 19 May 2006 (has links)
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Previous issue date: 2006-05-19 / This work analyzes the reutilization of real estate of patrimonial interest, come back toward habitation. One understands as real estate of patrimonial interest the old ones that present relevant architectural typologies that must be preserved; some buildings that represent characteristic architectural styles of a determined period; some valued real estates for the history of the city (historical, memory and image signification that has of certain places) and buildings with exceptional artistic elements. In short, real estate of patrimonial interest. The place or site to be studied will be the neighborhood of the Ribeira, because is an area that protects a bigger interest for the historic patrimony of the city. The habitation use was thought as a booster element of revitalization processes of degradable historic site, contributing to the preservation of artistic, architectural and historic patrimony, and thus to stimulate the accomplishment of the re-qualification of the neighborhood of the Ribeira. It is intended with the present study to examine alternatives to make possible habitation re (uses) in the historical quarter of the Ribeira in old constructions of patrimonial value / O trabalho analisa o potencial de reutiliza??o de im?veis de interesse patrimonial voltados para a habita??o. Entende-se como im?veis de interesse patrimonial os im?veis antigos que apresentam tipologias arquitet?nicas relevantes que devam ser preservadas; algumas edifica??es representativas de estilos arquitet?nicos caracter?sticos de um determinado per?odo; alguns im?veis de valor para a hist?ria da cidade (significa??o hist?rica e de mem?ria ou imagens que se t?m de certos lugares) e pr?dios com elementos art?sticos excepcionais. O s?tio estudado foi o bairro da Ribeira, pois ? uma ?rea que resguarda um maior interesse para o Patrim?nio Hist?rico da Cidade de Natal. O uso habitacional foi considerado como um elemento impulsionador de processos de revitaliza??o de ?reas hist?ricas degradadas, contribuindo para a preserva??o do Patrim?nio Hist?rico, Art?stico e Arquitet?nico, e assim estimulando a realiza??o da requalifica??o do bairro da Ribeira. Pretende-se com o presente estudo examinar alternativas para viabilizar re-usos habitacionais no referido bairro hist?rico em edifica??es antigas de valor patrimonial
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Influ?ncia da laparoscopia e da laparotomia na gasometria, leucometria diferencial e citocinas em modelo de sepse abdominal em ratosAra?jo Filho, Irami 27 October 2005 (has links)
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Previous issue date: 2005-10-27 / Laparoscopic surgery is associated with reduced surgical trauma, and less acute phase response, as compared with open surgery. Cytokines are important regulators of the biological response to surgical and anesthetic stress. The aim of this study was to determine if CO2 pneumoperitoneum would change cytokine expression, gas parameters and leukocyte count in septic rats. Methods: Wistar rats were randomly assigned to five groups: control (anesthesia only), laparotomy, CO2 pneumoperitoneum, cecum ligation and puncture by laparotomy, and laparoscopic cecum ligation and puncture. After 30 min of the procedures, arterial blood samples were obtained to determine leukocytes subpopulations by hemocytometer. TNFα, IL-1β, IL-6 were determined in intraperitoneal fluid (by ELISA). Gas parameters were measured on arterial blood, intraperitoneal and subperitoneal exsudates. Results: Peritoneal TNFα, IL-1β and IL-6 concentrations were lower in pneumoperitoneum rats than in all other groups (p<0.05). TNFα, IL-1β and IL-6 expression was lower in the laparoscopic than in laparotomic sepsis (p<0.05). Rats from laparoscopic cecum ligation and puncture group developed significant hypercarbic acidosis in blood and subperitoneal fluid when compared to open procedure group. Total white blood cells and lymphocytes were significantly lower in laparoscopic cecum ligation and puncture rats than in the laparotomic (p<0.01). Nevertheless, the laparotomic cecum ligation rats had a significant increase in blood neutrophils and eosinophils when compared with controls (p<0.05). Conclusions: This study demonstrates that the CO2 pneumoperitoneum reduced the inflammatory and immune response in an animal model of peritonitis with respect to intraperitoneal cytokines, white blood cell count and clinical correlates of sepsis. The pneumoperitoneum produced hypercarbic acidosis in septic animals / A cirurgia laparosc?pica est? associada com trauma reduzido e baixa resposta metab?lica na fase aguda do trauma, quando comparada com a cirurgia aberta. As citocinas e o balan?o ?cido-base s?o fatores importantes da resposta biol?gica ao trauma cir?rgico-anest?sico. O objetivo deste estudo foi determinar se o pneumoperit?nio com CO altera a express?o das citocinas intraperitoneais, a gasometria do sangue arterial, dos exsudatos intraperitoneal e subperitoneal, e a contagem diferencial de leuc?citos em ratos com sepse abdominal. M?todo: Ratos Wistar foram aleatoriamente distribu?dos em cinco grupos: controle (somente 2anestesia), laparotomia, pneumoperit?nio com CO2, ligadura e pun??o do ceco por laparotomia, ligadura e pun??o do ceco por laparoscopia. Ap?s 30 minutos dos procedimentos, sangue arterial foi colhido para leucometria em hemocit?metro. FNTα, IL-1β e IL-6 foram dosadas no lavado intraperitoneal (por ELISA). Os par?metros gasosos foram medidos no sangue arterial e nos exsudatos intraperitoneal e subperitoneal. Resultados: Os valores de FNTα, IL-1β e IL-6 foram significantemente menores nos ratos submetidos ao pneumoperit?nio do que em todos os outros grupos (p<0.05). Express?o de FNTα, IL-1β e IL-6 foi menor no grupo sepse induzida por laparoscopia do que por laparotomia (p<0.05). Os ratos submetidos ? ligadura e pun??o do ceco por via laparosc?pica desenvolveram acidose hiperc?rbica no sangue arterial e exsudato subperitoneal, mais intensa do que no grupo sepse laparot?mica. Leucopenia e linfopenia foram mais acentuadas no grupo sepse laparosc?pica (p<0.01). Entretanto, os animais submetidos a sepse laparot?mica desenvolveram significante aumento de neutr?filos e eosin?filos quando comparados com os controles (p<0.05). Conclus?es: Este estudo demonstrou que o pneumoperit?nio com CO contribuiu para reduzir a resposta inflamat?ria e imunol?gica em ratos submetidos a modelo de sepse abdominal, no que diz respeito a citocinas intraperitoneais e leucometria diferencial. O pneumoperit?nio tamb?m contribuiu para instala??o de acidose hiperc?rbica nos ratos s?pticos
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