No description available.

No description available.

No description available.

Prediction of the sound field in large urban environments has been limited thus far by the heavy computational requirements of conventional numerical methods such as boundary element (BE), finite-difference time-domain (FDTD), or ray-tracing methods. Recently, a considerable amount of work has been devoted to developing energy-based methods for this application, and results have shown the potential to compete with conventional methods. However, these developments have been limited to two-dimensional (2-D) studies (along street axes), and no real description of the phenomena at issue has been exposed (e.g., diffraction effects on the predictions). The main objectives of the present work were (i) to evaluate the feasibility of an energy-based method, the diffusion model (DM), for sound-field predictions in large, 3-D complex urban environments, (ii) to propose a numerical hybrid method that could improve the accuracy and computational time of these predictions, and (iii) to verify the proposed hybrid method against conventional numerical methods. The proposed numerical hybrid method consists of a full-wave model coupled with an energy-based model. The full-wave model is used for predicting sound propagation (i) near the source, where constructive and destructive interactions between waves are substantial, and (ii) outside the cluttered environment, where free-field-like conditions apply. The energy-based model is used in regions where diffusion conditions are met. The hybrid approach, as implemented in this work, is a combination of FDTD and DM models. Results from this work show the role played by diffraction near buildings edges close to the source and near the exterior boundaries of the computational domain, and its impact on the predictions. A wrong modeling of the diffraction effects in the environment leads to significant under or overpredictions of the sound levels in some regions, as compared to conventional numerical methods (in these regions, some differences are as high as 10 dB). The implementation of the hybrid method, verified against a full FDTD model, shows a significant improvement of the predictions. The mean error thus obtained inside the cluttered region of the environment is 1.5 dB. / Master of Science

Enzyme-catalyzed biofuel cells would be a great alternative to current battery technology, as they are clean, safe, and capable of using diverse and abundant renewable biomass with high energy densities, at mild reaction conditions. However, currently, three largest technical challenges for emerging enzymatic fuel cell technologies are incomplete oxidation of most fuels, limited power output, and short lifetime of the cell. Synthetic pathway biotransformation is a technology of assembling a number of enzymes coenzymes for producing low-value biocommodities. In this work, it was applied to generate bioelectricity for the first time. Non-natural enzymatic pathways were developed to utilize maltodextrin and glucose in enzymatic fuel cells. Three immobilization approaches were compared for preparing enzyme electrodes. Thermostable enzymes from thermophiles were cloned and expressed for improving the lifetime and stability of the cell. To further increase the power output, non-immobilized enzyme system was demonstrated to have higher power densities compared to those using immobilized enzyme system, due to better mass transfer and retained native enzyme activities. With the progress on pathway development and power density/stability improvement in enzymatic fuel cells, a high energy density sugar-powered enzymatic fuel cell was demonstrated. The enzymatic pathway consisting of 13 thermostable enzymes enabled the complete oxidation of glucose units in maltodextrin to generate 24 electrons, suggesting a high energy density of such enzymatic fuel cell (300 Wh/kg), which was several folds higher than that of a lithium-ion battery. Maximum power density was 0.74 mW/cm2 at 50 deg C and 20 mM fuel concentration, which was sufficient to power a digital clock or a LED light. These results suggest that enzymatic fuel cells via synthetic pathway biotransformation could achieve high energy density, high power density and increased lifetime. Future efforts should be focused on further increasing power density and enzyme stability in order to make enzymatic fuel cells commercially applicable. / Ph. D.

Several measurements may be used as error signals to determine how to appropriately control a sound field. These include pressure, particle velocity, energy density and intensity. In this thesis, numerical models are used to show which signals perform best in is free-field active noise control (ANC) using error sensors located in the near field of the sound sources. The second is equalization in a free field and a semi-free field. Minimized energy density total power output (MEDToPO) plots are developed; these indicate the maximum achievable attenuation for a chosen error sensor as a function of location. A global listening area equalization coefficient (GLAEC) is found to evaluate the performance of the equalization methods. It is calculated by finding the average of the spectral standard deviation of several frequency response measurements in a specified listening area. For free-field ANC employing error sensors located in the near field, pressure-based measurements perform the best. For free-field equalization over an extended listening region, total energy density performs best. Equalization of an extended listening region is more successful over a limited low-frequency bandwidth.

O objetivo deste trabalho foi estudar o perfil oxidativo de concentrados para bovinos adicionados de óleo de soja, refinado e degomado, em um período de armazenamento de 15 dias, sob as temperaturas de 25ºC e 40ºC. Foram formados cinco grupos de alimentos: controle (C) sem adição de óleo, tratamentos (T) 1, 2, 3 e 4 com adição de 2, 4, 6 e 8%, respectivamente, de óleo de soja refinado ou degomado. Para tal, foram avaliados os índices de peróxidos e de acidez. Com relação à influência da temperatura de estocagem, ao longo do período experimental à 25ºC, não houve alteração com relação aos valores de índice de peróxido quando se adicionou óleo de soja refinado aos concentrados, contudo, à 40ºC, houve aumento observando-se um valor máximo em torno de 0,9 mEq/kg de concentrado. O índice de acidez do óleo refinado extraído dos concentrados armazenados à 25ºC não foi alterado ao longo do período de armazenamento, e à 40ºC resultou em aumento de 19, 25, 44 e 44% para os respectivos T1, T2, T3 e T4 em relação ao controle. Quanto à influência do tipo de óleo processado na oxidação lipídica dos concentrados armazenados à 40ºC, a adição de óleo de soja refinado não alterou os índices de peróxidos dos concentrados ao longo dos 15 dias de experimento, e para o degomado observou-se um aumento no 3º dia de armazenamento em 57%, 44%, 123% e 93% para os respectivos T1, T2, T3 e T4, em relação ao controle. Também, o efeito da adição de óleo de soja degomado resultou em aumento do índice de acidez de 21%, 36%, 43% e 57% a partir do 5º dia de experimento, em relação ao 1º dia. Conclui-se que durante os 15 dias de armazenamento, houve diferença no perfil oxidativo dos concentrados adicionados de óleo de soja quando se comparou as temperaturas de 25ºC e 40ºC, mas se manteve inalterado quando se avaliou os tipos de óleo refinado e degomado em diferentes porcentagens. Assim, a adição de óleo de soja refinado ou degomado não altera o perfil oxidativo do concentrado para bovino sob as condições deste estudo. / The objective of this work was to study the oxidative profile of concentrates for cattle added soybean oil, refined and degummed in a storage period of 15 days, at temperatures of 25ºC and 40ºC. Were formed five food groups: control (C) without addition of oil, treatments (T) 1, 2, 3 and 4 with the addition of 2, 4, 6 and 8%, respectively, of refined or degummed soybean oil. For this purpose ware available index of peroxide and of acidic. Regarding the influence of storage temperature, the addition of refined soybean oil did not alter the values of the peroxide during the trial period at 25ºC, however, at 40ºC of storage of food alter this parameter and was shown a maximum value about 0.9 mEq/kg of concentrate. The acidity of refined oil extracted from concentrates stored at 25ºC was not changed during the storage period, and 40ºC resulted in an increase of 19, 25, 44 and 44% for the respective T1, T2, T3 and T4 compared the control. Regarding the influence of oil processed in lipid oxidation of concentrates stored at 40ºC, the addition of refined soybean oil did not alter the levels of peroxide concentrates over the 15 days of experiment, and the degummed observed an increase in 3rd day of storage in 57%, 44%, 123% and 93% for the respective T1, T2, T3 and T4, compared to control. Also, the effect of addition of crude soybean oil resulted in increased acid value of 21%, 36%, 43% and 57% from the 5th day of experiment, as compared to day 1. Thus, the addition of refined soybean oil or degummed not change profile for bovine oxidative concentrated under the conditions of this study.

Introdução. O consumo de açúcares aumentou consideravelmente nas últimas décadas, bem como a incidência e a prevalência da obesidade, gerando a elaboração de recomendações para moderá-lo. Os açúcares contribuem para a palatabilidade dos alimentos, podendo também aumentar sua densidade energética (DE), outro fator de risco para obesidade. Uma alternativa seria a substituição por adoçantes não calóricos, que também aumentam a palatabilidade dos alimentos, porém são isentos calorias. No entanto, ainda não existe consenso a respeito das implicações desta substituição principalmente na redução da ingestão energética e do peso corporal. Objetivo. Identificar a DE da dieta, a ingestão energética total e de macronutrientes, segundo consumo de adoçantes e/ou alimentos processados com adoçantes por adultos e idosos. Métodos. Estudo transversal, no qual foram coletados dados de sexo; idade; peso e estatura, para cálculo do IMC; consumo de adoçantes, por questionário adaptado e pelo recordatório de 24 horas, foram calculadas as médias de DE, de ingestão energética total e de macronutrientes. Para verificar associação entre variáveis independentes (idade, sexo, IMC, uso de adoçantes não calóricos) com a dependente \"classificação da DE foi realizada regressão logística, considerando dietas com alta DE aquelas com 1,5 Kcal/g ou mais. Para comparação das médias de ingestão energética e de macronutrientes, entre usuários de adoçantes e não usuários, foi utilizado o Teste t de Student (p 0,05) pelo Stata 10.0. Resultados. Participaram do estudo 168 indivíduos, com idade média de 54,8 anos (DP = 14,9 anos), sendo 84,5 por cento do sexo feminino, 67,9 por cento com sobrepeso ou obesidade e 44,1 por cento usuários de adoçantes. A média da DE das dietas de usuários de adoçantes foi 1,15 Kcal/g (IC 95 por cento [1,11; 1,19]), e de não usuários 1,28 Kcal/g (IC 95 por cento [1,23; 1,33]). Para regressão logística, as variáveis contínuas, idade e IMC, foram categorizadas, porém esta última não permaneceu no modelo final (p > 0,10). Apesar de não significativo, a variável sexo permaneceu no modelo como ajuste. A classificação da idade (p = 0,042) e o uso de adoçantes (p = 0,002) apresentaram associação com os menores valores de DE. Não foi encontrada diferença nas médias de ingestão energética e de macronutrientes entre os grupos. Conclusão. Uso de adoçantes se associou com menores valores de DE, mas não houve diferença no consumo energético total e de macronutrientes entre grupos / The consumption of sugar has increased considerably in recent decades, as well as the incidence and prevalence of obesity, leading the development of recommendations to moderate this consumption. Sugars contribute to the palatability of food, but may also increase their energy density (ED), which is an important obesitys risk factor. An alternative would be replacing sugar by non-caloric sweeteners, which increase the palatability of foods, but with free calories. However, the implications of this substitution in reducing energy intake and body weight are controversial. Objective. Identify the ED of diets, the total energy intake and macronutrient consumption according to the consumption of sweeteners and/or processed foods with sweeteners by adults and elderly. Methods. A cross sectional study, that collected data on gender, age, weight and height, to calculate BMI, consumption of non-caloric sweeteners, by questionnaire and with data from 24-hour recall, were calculated the average of ED, total energy intake and total macronutrient intake. Logistic regression was performed to assess the association between independent variables (age, gender, BMI, use of non-caloric sweeteners) and the dependent classification of ED, considering diets with high ED those with 1.5 kcal/g or more. To compare the means of total energy intake and total macronutrient intake, among noncaloric sweeteners users and nonusers, was used the Students t test (p 0.05) by Stata 10.0. Results. Were collected data form 168 individuals, with an average age of 54.8 years (SD = 14.9 years), 84.5 per cent female, 67.9 per cent overweight or obese and 44.1 per cent users of sweeteners. The mean of ED diets of non-caloric sweeteners users was 1.15 kcal/g (CI 95 per cent [1.11; 1.19]), and 1.28 Kcal/g (CI 95 per cent [1.23; 1.33]) for non-users. For logistic regression the continuous variables, BMI and age, were categorized, but the former did not remained in the final model. Although the variable gender was not significant it remained in the model for adjustment. The classification of age (p = 0.042) and the use of sweeteners (p = 0.002) were associated with lower values of ED. No difference was found in the means of total energy intake and total macronutrient intake between the groups. Conclusion. The use of sweeteners was associated with lower values of ED, but there was no difference in the means of total energy intake and total macronutrient intake between the groups

Made available in DSpace on 2017-07-21T19:25:51Z (GMT). No. of bitstreams: 1 Fernando Camilotti.pdf: 2665595 bytes, checksum: 785710d19df5786aef751b2d0407abea (MD5) Previous issue date: 2016-03-11 / The use of fiber posts in endodontic teeth restorations has been very frequent. These posts have conical shape and it is usually formed by glass fibers packaged in epoxy resin. Microscopy studies were conducted to investigate the structure of four models of fiberglass posts manufactured by FGM (DC 0.5, DC1, DC2 and DC3 models), and it was possible to verify inhomogeneities. The models of posts used in this study are translucent and, in clinical use, it is cemented into the tooth with light curing activated resin. During the clinical procedure of cementing a post in the tooth, light from a curing light impinge at the base of the post transmitting light to its interior. Part of this light is spread out by the side surface of the post. This study proposes a new methodology in order to investigate the spreading of light by endodontic posts in the orthogonal direction to its axis. This methodology fills out an dentist demand, e by means of it, it is possible to obtain light intensity profiles spread out along the length of a post. Comparing to previously published methods, this one uses the phase sensitive detection and the possibility to control the optical aperture in the experiment. The resulting profiles show a like exponential decay of light along the post, which allow us to obtain an linear attenuation coefficient for the different posts models studied. From the experimental results it is shown a way to calculate the light density of volumetric energy inside the post. The advantages of this new method are: (a) the results lead to much better characterization of the samples with more measured points and (b) the small optical aperture that provides better resolution. / O uso de pinos endodônticos em restaurações de dentes tem sido muito frequente. Estes pinos são formados, em geral, por fibras de vidro envolvidas e compactadas em epóxi, possuindo um formato cônico. Estudos de microscopia foram realizados para investigar a estrutura de quatro modelos de pinos de fibra de vidro do fabricante FGM (modelos DC 0.5, DC1, DC2 e DC3), e constatou-se falta de homogeneidade. Os modelos de pinos usados neste trabalho são transparentes e, no uso clínico, são cimentados no interior do dente com uma resina que tem a cura ativada por luz. No procedimento de cimentação de um pino no dente, a luz de um aparelho fotopolimerizador incide na base do pino transmitindo luz para seu interior. Parte desta luz é espalhada pela superfície lateral do pino. Este trabalho propõem um novo método para investigar o espalhamento da luz por pino endodônticos, na direção ortogonal ao seu eixo. Esta investigação atende uma demanda da odontologia, e como resultado do novo método, obtemos perfis de intensidade de luz espalhada ao longo do comprimento de um pino. O diferencial deste novo método, em relação aos métodos já publicados, é o emprego da detecção sensível à fase e a possibilidade de controlar a abertura ótica no experimento. Os perfis de espalhamento apontam para uma queda do tipo exponencial da luz ao longo do pino e isso possibilitou obter coeficientes de atenuação lineares para os diferentes modelos de pinos estudados. Com os resultados experimentais, é indicada uma forma de calcular a densidade volumétrica média de energia luminosa no interior do pino. As vantagens deste novo método são: (a) os resultados apresentam melhor caracterização das amostras por apresentar mais pontos de medida e (b) pela abertura ótica ser pequena ocorre a garantia de uma melhor resolução de medida.

Introdução. O consumo de açúcares aumentou consideravelmente nas últimas décadas, bem como a incidência e a prevalência da obesidade, gerando a elaboração de recomendações para moderá-lo. Os açúcares contribuem para a palatabilidade dos alimentos, podendo também aumentar sua densidade energética (DE), outro fator de risco para obesidade. Uma alternativa seria a substituição por adoçantes não calóricos, que também aumentam a palatabilidade dos alimentos, porém são isentos calorias. No entanto, ainda não existe consenso a respeito das implicações desta substituição principalmente na redução da ingestão energética e do peso corporal. Objetivo. Identificar a DE da dieta, a ingestão energética total e de macronutrientes, segundo consumo de adoçantes e/ou alimentos processados com adoçantes por adultos e idosos. Métodos. Estudo transversal, no qual foram coletados dados de sexo; idade; peso e estatura, para cálculo do IMC; consumo de adoçantes, por questionário adaptado e pelo recordatório de 24 horas, foram calculadas as médias de DE, de ingestão energética total e de macronutrientes. Para verificar associação entre variáveis independentes (idade, sexo, IMC, uso de adoçantes não calóricos) com a dependente \"classificação da DE foi realizada regressão logística, considerando dietas com alta DE aquelas com 1,5 Kcal/g ou mais. Para comparação das médias de ingestão energética e de macronutrientes, entre usuários de adoçantes e não usuários, foi utilizado o Teste t de Student (p 0,05) pelo Stata 10.0. Resultados. Participaram do estudo 168 indivíduos, com idade média de 54,8 anos (DP = 14,9 anos), sendo 84,5 por cento do sexo feminino, 67,9 por cento com sobrepeso ou obesidade e 44,1 por cento usuários de adoçantes. A média da DE das dietas de usuários de adoçantes foi 1,15 Kcal/g (IC 95 por cento [1,11; 1,19]), e de não usuários 1,28 Kcal/g (IC 95 por cento [1,23; 1,33]). Para regressão logística, as variáveis contínuas, idade e IMC, foram categorizadas, porém esta última não permaneceu no modelo final (p > 0,10). Apesar de não significativo, a variável sexo permaneceu no modelo como ajuste. A classificação da idade (p = 0,042) e o uso de adoçantes (p = 0,002) apresentaram associação com os menores valores de DE. Não foi encontrada diferença nas médias de ingestão energética e de macronutrientes entre os grupos. Conclusão. Uso de adoçantes se associou com menores valores de DE, mas não houve diferença no consumo energético total e de macronutrientes entre grupos / The consumption of sugar has increased considerably in recent decades, as well as the incidence and prevalence of obesity, leading the development of recommendations to moderate this consumption. Sugars contribute to the palatability of food, but may also increase their energy density (ED), which is an important obesitys risk factor. An alternative would be replacing sugar by non-caloric sweeteners, which increase the palatability of foods, but with free calories. However, the implications of this substitution in reducing energy intake and body weight are controversial. Objective. Identify the ED of diets, the total energy intake and macronutrient consumption according to the consumption of sweeteners and/or processed foods with sweeteners by adults and elderly. Methods. A cross sectional study, that collected data on gender, age, weight and height, to calculate BMI, consumption of non-caloric sweeteners, by questionnaire and with data from 24-hour recall, were calculated the average of ED, total energy intake and total macronutrient intake. Logistic regression was performed to assess the association between independent variables (age, gender, BMI, use of non-caloric sweeteners) and the dependent classification of ED, considering diets with high ED those with 1.5 kcal/g or more. To compare the means of total energy intake and total macronutrient intake, among noncaloric sweeteners users and nonusers, was used the Students t test (p 0.05) by Stata 10.0. Results. Were collected data form 168 individuals, with an average age of 54.8 years (SD = 14.9 years), 84.5 per cent female, 67.9 per cent overweight or obese and 44.1 per cent users of sweeteners. The mean of ED diets of non-caloric sweeteners users was 1.15 kcal/g (CI 95 per cent [1.11; 1.19]), and 1.28 Kcal/g (CI 95 per cent [1.23; 1.33]) for non-users. For logistic regression the continuous variables, BMI and age, were categorized, but the former did not remained in the final model. Although the variable gender was not significant it remained in the model for adjustment. The classification of age (p = 0.042) and the use of sweeteners (p = 0.002) were associated with lower values of ED. No difference was found in the means of total energy intake and total macronutrient intake between the groups. Conclusion. The use of sweeteners was associated with lower values of ED, but there was no difference in the means of total energy intake and total macronutrient intake between the groups