24 resultados para Radiação ultravioleta - Teses

em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (BDPI/USP)


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Accurate iris reproduction in the fabrication of ocular prosthesis in order to match the remaining eye is a key factor to mask the loss and achieve an esthetic outcome for anophthalmic patients. This study evaluated the stability of acrylic paints used for replicating iris color in ocular prostheses by the analysis of two factors: the temperature of the acrylic resin polymerization cycle during prosthesis fabrication and the incidence of sun light, which is the main photodegrading agent undermining the longevity of ocular prostheses. An accelerated aging assay was used for both analyses. Specimens simulating the prosthetic iris in the colors blue, yellow, black, brown and green were fabricated, and were submitted to a colorimetric reading before and after undergoing the thermal conditions of acrylic resin polymerization. Next, the specimens were submitted to an artificial accelerated aging assay with ultraviolet radiation A and weekly colorimetric readings during a 3-week period. The color change (??*) values for the four specimens painted with the same color paint were averaged and the resulting values were considered for statistical analysis. Levine's test and Student's t-test were used to analyze the influence of the temperature of the polymerization cycle during prosthesis fabrication on the color stability of each acrylic resin paint. Friedman's test for three dependent samples was used for analysis of color photodegradation as function of time. Significance level was set at 0.05 for all analyses. It was observed that, after the action of the temperature of the polymerization cycle, alteration above clinically acceptable level of ??*> 3.3 was observed only for the yellow color. After the accelerated aging assay, there were statistically significant differences (p<0.05) as a function of time in the green, brown, black and blue colors. Changes were clinically acceptable for the brown and black colors; slightly above the clinically acceptable limit for the green color; and significantly high and impracticable from a clinical standpoint for the blue color. There was no statistically significant differences (p>0.05) for the yellow color, which presented color change only a little above the clinically acceptable limit. In conclusion: 1. Only the yellow color presented alterations above the clinically acceptable levels after the polymerization cycle; 2. After accelerated aging, there was no changes in the yellow color above the clinically acceptable levels; 3. For the green color, degradation was significant and slightly above the clinically acceptable levels; 4. The black, brown and blue colors presented significant alterations as function of time; the alterations of the brown and black colors were within acceptable clinical levels, while the blue color presented a more accentuated degradation over time.

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This paper presents the study of photochemical behavior of polycyclic aromatic hydrocarbons (PAHs), potential pollutants in secondary reactions in aerosols, through Raman spectroscopy compared with its electrochemical behavior. The PAHs studied include pyrene, anthracene, phenanthrene and fluorene. These were adsorbed onto TiO2 and irradiated with ultraviolet light (254 nm). Their electrochemical oxidation was studied by in situ Surface-enhanced Raman Scattering (SERS) and led to the formation of carbonyl-containing products. Oxidized intermediates bearing the C=O group were also formed during photodegradation. The joint analysis of the photodegradation data with those produced by electrochemical means - using spectroscopic techniques for the identification and characterization of the products - revealed the formation of identical products for anthracene, but not for pyrene. A reasonable explanation for this difference in results is that photochemical and electrochemical oxidation reactions proceed via different mechanisms. While photocatalytic degradation over TiO2 is initiated by hydroxyl radicals, electrochemical oxidation is initiated by the direct electron transfer from adsorbed PAH to the electrode, generating PAH cation radicals that undergo subsequent reactions.

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Since 2000, spore dosimetry and spectral photometry have been performed in parallel at the Southern Space Observatory, São Martinho da Serra (Southern Brazil). A comparative study involving data from Punta Arenas - Chile (53.2º S), São Martinho da Serra (29.5º S), Padang - Indonesia (0.9ºS), Brussels - Belgium (50.9º N) and Kiyotake - Japan (31.9º N) from 2000 to 2006 is presented. The Spore Inactivation Doses presented the higher values in summer (973 ± 73 for Punta Arenas and 4,369 ± 202 for São Martinho da Serra, as well 1,402 ± 170 and 3,400 ± 1,674 for Brussels and Kiyotake, respectively). The simplicity, robustness and high resistance of bacterial spores makes the biosensor an potential biological tool for UV-B monitoring.

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INTRODUÇÃO: quanto menor a dimensão do voxel, maior a nitidez da imagem de tomografia computadorizada Cone-Beam (TCCB), porém, maior a dose de radiação emitida. OBJETIVOS: avaliar e comparar a reprodutibilidade da mensuração da espessura das tábuas ósseas vestibular e lingual em imagens de TCCB, utilizando diferentes protocolos de aquisição de imagem com variação da dimensão do voxel. MÉTODOS: exames de TCCB foram tomados de 12 mandíbulas humanas secas, com dimensão do voxel de 0,2; 0,3 e 0,4mm, no aparelho i-CAT Cone-Beam 3-D Dental Imaging System. No software i-CAT Viewer, foi mensurada a espessura das tábuas ósseas vestibular e lingual, em um corte axial passando 12mm acima do forame mentoniano do lado direito. A reprodutibilidade intraexaminador foi avaliada por meio da aplicação do teste t pareado. Para a comparação interexaminadores, foi utilizado o teste t independente. Os resultados foram considerados com o nível de significância de 5%. RESULTADOS: observou-se uma excelente reprodutibilidade interexaminadores para os três protocolos avaliados. A reprodutibilidade intraexaminadores foi muito boa, com exceção de algumas regiões dos dentes anteriores, que mostraram diferenças estatisticamente significativas, independentemente da dimensão do voxel. CONCLUSÃO: a mensuração da espessura das tábuas ósseas vestibular e lingual em imagens de TCCB mostrou boa precisão para exames obtidos com voxel de 0,2; 0,3 ou 0,4mm. A reprodutibilidade das mensurações na região anterior da mandíbula foi mais crítica do que na região posterior.

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Roofing provides the main protection against direct solar radiation in animal housing. Appropriate thermal properties of roofing materials tend to improve the thermal comfort in the inner ambient. Nonasbestos fiber-cement roofing components reinforced with cellulose pulp from sisal (Agave sisalana) were produced by slurry and dewatering techniques, with an optional addition of polypropylene fibers. Nonasbestos tiles were evaluated and compared with commercially available asbestos-cement sheets and ceramic tiles (frequently chosen as roofing materials for animal housing). Thermal conductivity and thermal diffusivity of tiles were determined by the parallel hot-wire method, along with the evaluation of the downside surface temperature. Cement-based components reinforced with sisal pulp presented better thermal performance at room temperature (25ºC), while those reinforced with sisal pulp added by polypropylene fibers presented better thermal performance at 60ºC. Non-asbestos cement tiles provided more efficient protection against radiation than asbestos corrugated sheets.

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OBJETIVO: caracterizar a inserção de egressos do Curso de Fonoaudiologia da Universidade Estadual Paulista (UNESP) - Marília, em Programas de Pós-Graduação (PPG) Stricto Sensu brasileiros. MÉTODO: foram utilizadas listas de graduados e Curriculum Vitae do egresso e do orientador. RESULTADOS: dos 537 formados, 16,57% cursaram/estavam cursando PPG e destes, 98,88% em mestrado e 37,08% também em doutorado. Na grande área de conhecimento, 50% dos egressos de mestrado vincularam-se predominantemente a programas em Ciências da Saúde, 31,80% em Ciências Humanas e 13,64% em Linguística, Letras e Artes. No doutorado, 33, 33% em Ciências Humanas, 30,30% em Ciências da Saúde e em Linguística, Letras e Artes. Quanto à área de conhecimento, predominou a vinculação, no mestrado, de 30,68% em Fonoaudiologia, 28,41% em Educação, 13,64% em Linguística e 9,09% em Medicina I; e, no doutorado, de 33,33% em Educação, 30,30% em Linguística e 9,09% em Fonoaudiologia; 55,68% dissertações e 51,52% teses focalizaram a linguagem. A UNESP predominou com 39,77% no mestrado e 48,48% no doutorado. Predominou a vinculação a Programas com conceito 4 para 52,27% dos egressos do mestrado e 45,45% do doutorado. Quando constou a informação (55,68%), todos receberam fomento. O Teste de Razão de Verossimilhança não indicou diferenças significativas dos percentuais obtidos entre o mestrado e o doutorado. CONCLUSÃO: os resultados superaram os apresentados para o mesmo Estado, mostraram a característica interdisciplinar da Ciência Fonoaudiológica e o predomínio de temática em linguagem.

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Ozone and inhalable particulate matter are the major air pollutants in the Metropolitan Area of São Paulo, Brazil, a region that has more than 19 million inhabitants and approximately 7 million registered vehicles. Proximity of roadways, adjacent land use, and local circulation are just some of the factors that can affect the results of monitoring of pollutant concentrations. The so-called weekend effect (higher ozone concentrations on weekends than on weekdays) might be related to the fact that concentrations of ozone precursors, such as nitrogen oxides (NOx) and Non Methane-Hydrocarbon (NMHC), are relatively lower on weekends. This phenomenon has been reported in some areas of the United States since the 1970s. The differences between the concentrations of ozone in period of weekend and weekday, were obtained from analysis of data hourly average of CETESB for 2004, studied the precursors to the formation of troposphere ozone, the meteorological variables and traffic profile for RMSP. Because of the proximity to sources of emissions from the station Pinheiros showed higher concentrations of NO and NO² and greater variations to the periods weekend and weekday. With fewer vehicles circulating during the weekend, and consequently less emission of pollutants, it has cleaner air and less concentration of NO and NO², there is the ideal setting to the formation of troposphere ozone, despite the lower concentration of NO². The proximity with the source emissions, aided by the increased availability of solar radiation and the presence of ozone precursors, were factors conditions for the occurrence of weekend effect.

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The quantification of the available energy in the environment is important because it determines photosynthesis, evapotranspiration and, therefore, the final yield of crops. Instruments for measuring the energy balance are costly and indirect estimation alternatives are desirable. This study assessed the Deardorff's model performance during a cycle of a sugarcane crop in Piracicaba, State of São Paulo, Brazil, in comparison to the aerodynamic method. This mechanistic model simulates the energy fluxes (sensible, latent heat and net radiation) at three levels (atmosphere, canopy and soil) using only air temperature, relative humidity and wind speed measured at a reference level above the canopy, crop leaf area index, and some pre-calibrated parameters (canopy albedo, soil emissivity, atmospheric transmissivity and hydrological characteristics of the soil). The analysis was made for different time scales, insolation conditions and seasons (spring, summer and autumn). Analyzing all data of 15 minute intervals, the model presented good performance for net radiation simulation in different insolations and seasons. The latent heat flux in the atmosphere and the sensible heat flux in the atmosphere did not present differences in comparison to data from the aerodynamic method during the autumn. The sensible heat flux in the soil was poorly simulated by the model due to the poor performance of the soil water balance method. The Deardorff's model improved in general the flux simulations in comparison to the aerodynamic method when more insolation was available in the environment.

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Propôs-se, neste trabalho, estimar dados de albedo à superfície terrestre usando-se o sensor Thematic Mapper (TM) do satélite LANDSAT 5 e compará-lo com dados de duas estações agrometeorológicas localizadas em região de Cerrado e a outra em cultivo da cana-de-açúcar. A região de estudo está localizada no município de Santa Rita do Passa Quatro, SP, Brasil. Para a realização do estudo obtiveram-se seis imagens orbitais do satélite Landsat 5 sensores TM, na órbita 220 e ponto 75, nas datas de 22/02, 11/04, 29/05, 01/08, 17/08 e 21/11, todas do ano de 2005, a que correspondem os dias juliano de 53, 101, 149, 213, 229 e 325, respectivamente. As correções geométricas para as imagens foram realizadas e geradas as cartas de albedo. O algoritmo SEBAL estimou satisfatoriamente os valores de albedo de superfícies sobre áreas de cerrado e de cana-de-açúcar, na região de Santa Rita do Passa Quatro, SP, consistentes com observações realizadas do albedo à superfície.

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The General Ocean Turbulence Model (GOTM) is applied to the diagnostic turbulence field of the mixing layer (ML) over the equatorial region of the Atlantic Ocean. Two situations were investigated: rainy and dry seasons, defined, respectively, by the presence of the intertropical convergence zone and by its northward displacement. Simulations were carried out using data from a PIRATA buoy located on the equator at 23º W to compute surface turbulent fluxes and from the NASA/GEWEX Surface Radiation Budget Project to close the surface radiation balance. A data assimilation scheme was used as a surrogate for the physical effects not present in the one-dimensional model. In the rainy season, results show that the ML is shallower due to the weaker surface stress and stronger stable stratification; the maximum ML depth reached during this season is around 15 m, with an averaged diurnal variation of 7 m depth. In the dry season, the stronger surface stress and the enhanced surface heat balance components enable higher mechanical production of turbulent kinetic energy and, at night, the buoyancy acts also enhancing turbulence in the first meters of depth, characterizing a deeper ML, reaching around 60 m and presenting an average diurnal variation of 30 m.

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A common side effect of radiotherapy used in the treatment of oral cancer is the occurrence of structural and physiological alterations of the salivary glands due to exposure to ionizing radiation, as demonstrated by conditions such as decreased salivary flow. The present study evaluated ultrastructural alterations in the parotid glands of rats receiving a fractionated dose (1,500-cGy) of radiation emitted by a Cesium-137 source and rats that were not subjected to ionizing radiation. After sacrifice, the parotid glands were removed and examined by transmission electron microscopy. Damage such as cytoplasmic vacuolization, dilatation of the endoplasmic reticulum and destruction of mitochondria, as well as damage to the cellular membrane of acinar cells, were observed. These findings lead to the conclusion that ionizing radiation promotes alterations in the glandular parenchyma, and that these alterations are directly related to the dose level of absorbed radiation. Certain phenomena that appear in the cytoplasm and nuclear material indicate that ionizing radiation causes acinar cell death (apoptosis).

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Este trabalho avaliou a concentração dos radioelementos K, eU e eTh em amostras de granitos do Estado de Rondônia, Brasil. A análise estatística dos dados obtidos indicou que eles seguem distribuições lognormais. Os valores modais encontrados correspondem a cerca de 11% para K, 29 ppm para eU e 85 ppm para eTh. Correlações diretas significativas foram determinadas entre as concentrações dos três radioelementos, isto é, r = 0,71 (entre K e eU), r = 0,72 (entre K e eTh)e r = 0,72 (entre eU e eTh), sugerindo que são congruentes os processos de seu acúmulo nos minerais das rochas analisadas. Os dados de concentração permitiram estimar a taxa de dose absorvida de radiação no ar acima de 1 m do nível do terreno, a qual também segue uma distribuição lognormal, com valor modal de 2,7 mSv/ano, que é ligeiramente superior à média global de 2,4 mSv/ano. Os resultados obtidos também permitiram avaliar, do ponto de vista radiométrico, se os granitos analisados são adequados para emprego como revestimento em construção civil.

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The present research deals with two mural paintings made in 1947 with the fresco technique by Fulvio Pennacchi in the Catholic Chapel of the Hospital das Clínicas (São Paulo City, Brazil), namely the Virgin Annunciation and the Supper at Emmaus. This study regards the materials and painting techniques used by the artist, based on historical research,on in situ observations and laboratory analytical techniques (stereomicroscopy,scanning electron microscopy with an energy dispersive spectrometer, X-ray diffractometry, electron microprobe, images obtained with UV-light), aiming to improve the methods of characterization of objects of our cultural heritage, and to enhance its preservation accordingly. The results lead to the identification of the plaster components and of distinct layers in the frescoes, besides further information on grain size, impurities and textures, composition of pigments, and features of deterioration, such as efflorescences. The degree of degradation of the murals painting was assessed by this way. Our data suggest that a single layer of plaster was used by Pennacchi, as a common mortar with fine- and medium-grained aggregates. Differences in texture were obtained by adding gypsum to the plaster.

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Em meio às diversas transformações sofridas pelo casamento e pela família ao longo da história, várias configurações familiares convivem na contemporaneidade: nuclear, monoparental, homoparental, recomposta, entre outras possibilidades. Nesse contexto, aumenta, em vários países, e mais recentemente no Brasil, o número de casais que escolhem não ter filhos. O objetivo deste trabalho foi realizar uma revisão bibliográfica sobre o tema, incluindo publicações nacionais e internacionais. A busca foi feita em bases de dados (Web of Science, PsycINFO, Medline, SciELO, Lilacs, Psicodoc, BVS-Psi, Dedalus), e foram levantados artigos completos em periódicos indexados e resumos de teses e dissertações produzidas nos últimos dez anos. Os resultados coletados abordam diversas facetas do fenômeno da escolha contemporânea por não ter filhos: motivações declaradas, associação entre esse tipo de escolha e a situação profissional, relação com fatores de história de vida e família de origem, satisfação de vida e conjugal, preconceito e estereótipos negativos.

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Parte-se da hipótese de que tanto os modos de constituição da subjetividade, quanto as teses epistemológicas sobre a formação do eu têm sofrido importantes mudanças nas últimas décadas. No plano das identidades pessoais, tal fato se expressa no atenuamento do ideário intimista, tradicionalmente centrado na idéia da vida mental como espaço privado e interior. No plano epistemológico, diferentes saberes vêm questionando a equivalência entre vida mental e interioridade psicológica e propondo descrições da origem do eu que incluam a dimensão da corporeidade e da ação. Considerando as noções de representação e de ação como eixos fundamentais para diferentes concepções da subjetividade, este artigo examina um modelo internalista do psiquismo, contrastando-o com outro que toma o eu como agente corporificado.