The flapping path of a single airfoil and dual airfoils in a biplane configuration is optimized for maximum thrust and/or propulsive efficiency. Unsteady, low speed viscous flows are computed using a Navier-Stokes solver in a parallel computing environment. A gradient based algorithm and Response Surface Methodology (RSM) are employed for optimization. The evaluation of gradient vector components and the design of experiments for RSM, which require unsteady solutions, are also carried out in parallel. Parallel computations are performed using Parallel Virtual Machine (PVM) library. First, a single airfoil undergoing a combined sinusoidal or non-sinusoidal pitching and plunging motion is studied. The non-sinusoidal flapping motion is described using an elliptic curve or Non-Uniform Rational B-Splines (NURBS). It is shown that the thrust generation may significantly be increased in comparison to the sinusoidal flapping motion. For a high thrust, the airfoil stays at high effective angle of attack values during the upstroke and the downstroke, and the effective pitching occurs at minimum and maximum plunge positions. Secondly, the optimization of sinusoidal and non-sinusoidal flapping paths of dual airfoils is considered. Moving and deforming overset grids are used for computations. The deforming overset grids remove the restrictions on the flapping motion, and improve the optimization results obtained earlier. At low flapping frequencies, an airfoil in a biplane configuration produces more thrust than a single airfoil. Yet, at high frequencies the airfoil in biplane configuration produces less thrust at a significantly lower efficiency than the single airfoil.

A robust simulation-based optimization approach is proposed for truck-shovel systems in surface coal mines to maximize the expected value of revenue obtained from loading customer trains. To this end, a large surface coal mine in North America is considered as case study. A data-driven modeling framework is developed and then applied to automatically generate a highly detailed simulation model of the mine in Arena. The framework comprises a formal information model based on Unified Modeling Language (UML), which is used to input mine structural as well as production information. Petri net-based model generation procedures are applied to automatically generate the simulation model based on the whole set of simulation inputs. Then, factors encountered in material handling operations that may affect the robustness of revenue are then classified into 1) controllable; and 2) uncontrollable categories. While controllable factors are trucks locked to routes, uncontrollable factors are inverses of summation over truck haul, and shovel loading and truck-dumping times for each route. Historical production data of the mine contained in a data warehouse is used to derive probability distributions for the uncontrollable factors. The data warehouse is implemented in Microsoft SQL, and contains snapshots of historical equipment statuses and production outputs taken at regular intervals in each shift of the mine. Response Surface Methodology is applied to derive an expression for the variance of revenue as a function of controllable and uncontrollable factors. More specifically, 1) first order and second order effects for controllable factors, 2) first order effects for uncontrollable factors, and 3) two factor interactions for controllable and uncontrollable factors are considered. Latin Hypercube Sampling method is applied for setting controllable factors and the means of uncontrollable factors. Also, Common Random Numbers method is applied to generate the sequence of pseudo-random numbers for uncontrollable factors in simulation experiments for variance reduction between different design points of the metamodel. The variance of the metamodel is validated using leave-one-out cross validation. It is later applied as an additional constraint to the mathematical formulation to maximize revenue in the simulation model using OptQuest. The decision variables in this formulation are truck locks only. Revenue is a function of the actual quality of coal delivered to each customer and their corresponding quality specifications for premiums and penalties. OptQuest is an optimization add-on for Arena that uses Tabu search and Scatter search algorithms to arrive at the optimal solution. The upper bound on the variance as a constraint is varied to obtain different sets of expected value as well as variance of optimal revenue. After comparison with results using OptQuest with random sampling and without variance expression of metamodel, it has been shown that the proposed approach can be applied to obtain the decision variable set that not only results in a higher expected value but also a narrower confidence interval for optimum revenue. According to the best of our knowledge, there are two major contributions from this research: 1) It is theoretically demonstrated using 2-point and orthonormal k-point response surfaces that Common Random Numbers reduces the error in estimation of variance of metamodel of simulation model. 2) A data-driven modeling and simulation framework has been proposed for automatically generating discrete-event simulation model of large surface coal mines to reduce modeling time, expenditure, as well as human errors associated with manual development.

Lipases are widely researched enzyme group because of their ability to catalyze a wide range of synthesis reactions. The aim of this doctoral thesis was to study and optimize fatty acid ester synthesis using lipases. The influence of enzyme choice, its preparation (immobilization), choice of substrates and reaction conditions on fat hydrolysis, biodiesel and phenethyloctanoate (flavour ester) synthesis reaction course and yield was studied. Enterobacter aerogenes lipase, which was developed in Lithuania, was immobilized and its properties were determined for the first time. Commercial lipases were used for hydrolysis and synthesis reactions, the influence of reaction parameters was determined using response surface methodology, and so the yield was optimized. Silica gel was found to be a promising reaction additive for acyl group migration catalysis in biodiesel synthesis reaction. Different lipase specificities towards different acylglycerol classes and regioisomers varied greatly; on the basis of this knowledge two-step biodiesel synthesis catalysis was proposed. / Lipazių atranka ir taikymas riebalų rūgščių esterių sintezei Lipazės yra intensyviai tiriama fermentų grupė dėl jų gebos katalizuoti platų spektrą sintezės reakcijų. Disertacinio darbo tikslas buvo ištirti ir optimizuoti riebalų rūgščių esterių sintezės, panaudojant lipazes, būdus. Tirta fermento preparato paruošimo (imobilizavimo), fermento bei substratų pasirinkimo bei reakcijos sąlygų ir priedų įtaka riebalų hidrolizės, biodyzelino, fenetiloktanoato (kvapiojo esterio) sintezės reakcijų eigai ir išeigai. Pirmą kartą ištirtos Lietuvoje paruoštos Enterobacter aerogenes lipazės savybės, ji imobilizuota ant gamtinės kilmės nešiklių. Komercinių lipazių katalizuojamų reakcijų sąlygų įtakai nustatyti ir reakcijos išeigai optimizuoti naudota atsako paviršiaus metodologija. Tiriant reakcijos priedų įtaką acilgrupės migracijai ir biodyzelino sintezės reakcijai, nustatyta, kad perspektyvus priedas yra silikagelis. Lipazių specifiškumas ženkliai skiriasi skirtingoms acilglicerolių klasėms ir regioizomerams, šių žinių pagrindu buvo pasiūlyta dviejų etapų biodyzelino sintezės katalizė.

Lipazės yra intensyviai tiriama fermentų grupė dėl jų gebos katalizuoti platų spektrą sintezės reakcijų. Disertacinio darbo tikslas buvo ištirti ir optimizuoti riebalų rūgščių esterių sintezės, panaudojant lipazes, būdus. Tirta fermento preparato paruošimo (imobilizavimo), fermento bei substratų pasirinkimo bei reakcijos sąlygų ir priedų įtaka riebalų hidrolizės, biodyzelino, fenetiloktanoato (kvapiojo esterio) sintezės reakcijų eigai ir išeigai. Pirmą kartą ištirtos Lietuvoje paruoštos Enterobacter aerogenes lipazės savybės, ji imobilizuota ant gamtinės kilmės nešiklių. Komercinių lipazių katalizuojamų reakcijų sąlygų įtakai nustatyti ir reakcijos išeigai optimizuoti naudota atsako paviršiaus metodologija. Tiriant reakcijos priedų įtaką acilgrupės migracijai ir biodyzelino sintezės reakcijai, nustatyta, kad perspektyvus priedas yra silikagelis. Lipazių specifiškumas ženkliai skiriasi skirtingoms acilglicerolių klasėms ir regioizomerams, šių žinių pagrindu buvo pasiūlyta dviejų etapų biodyzelino sintezės katalizė. / Lipases are widely researched enzyme group because of their ability to catalyze a wide range of synthesis reactions. The aim of this doctoral thesis was to study and optimize fatty acid ester synthesis using lipases. The influence of enzyme choice, its preparation (immobilization), choice of substrates and reaction conditions on fat hydrolysis, biodiesel and phenethyloctanoate (flavour ester) synthesis reaction course and yield was studied. Enterobacter aerogenes lipase, which was developed in Lithuania, was immobilized and its properties were determined for the first time. Commercial lipases were used for hydrolysis and synthesis reactions, the influence of reaction parameters was determined using response surface methodology, and so the yield was optimized. Silica gel was found to be a promising reaction additive for acyl group migration catalysis in biodiesel synthesis reaction. Different lipase specificities towards different acylglycerol classes and regioisomers varied greatly; on the basis of this knowledge two-step biodiesel synthesis catalysis was proposed.

The purpose of this research was to determine the solubility of apricot (Prunus armeniaca L.) oil in supercritical carbon dioxide (SC-CO2), effects of parameters (particle size, solvent flow rate, pressure, temperature and co-solvent (ethanol) concentration) on extraction yield and to investigate the possibility of fractionation. Solubility, increased with pressure and increased with temperature above the crossover pressure, which was found between 200 and 300 bar, and decreased with temperature below the crossover pressure. Appropriate models were fitted to data. Extraction of apricot kernel oil occurred in two extraction periods as fast and slow extraction periods. Most of the oil was extracted in the fast extraction period and the oil recovered in the slow extraction period was negligible. Extraction yield increased with decrease in particle size and recovery of more than 99 % of the oil was possible if particle diameter decreased below 0.425 mm. Extraction rate increased with increase in flow rate, pressure, temperature and ethanol concentration. The volume mass transfer coefficient in the fluid phase changed between 0.6 and 3.7 /min, whereas the volume mass transfer coefficient in the solid phase changed between 0.00009 and 0.00048 /min. Extraction yield at 15 min for particle diameter smaller than 0.85 mm was formulated as a function of solvent flow rate, pressure, temperature, and ethanol concentration by using Response Surface Methodology. According to the model yield was highest (0.26 g /g) at 4 g/min flow rate, 60 oC, 450 bar and 3 % ethanol concentration. Fractionation was not possible at significant levels.

The main objective of this study was to optimize the processing conditions of breads baked in halogen lamp-microwave combination oven by using response surface methodology. It was also aimed to construct neural network models for the prediction of quality parameters of bread as a function of processing conditions. Different baking time and power combinations were used in order to find the optimum baking conditions of bread in halogen lamp-microwave combination oven. The independent variables were the baking time (4, 4.5, 5, 5.5, and 6 min), power of upper and lower halogen lamps (40, 50, 60, 70, and 80%), and power of the microwave (20, 30, 40, 50, and 60%). As control, breads baked in conventional oven at 200&ordm / C for 13 min were used. The measured quality parameters were the weight loss, color change, specific volume, porosity, and texture profile of the breads. Baking time, upper halogen lamp power, and microwave power were found to be significant on affecting most of the quality parameters. On the other hand, lower halogen lamp power was found to be an insignificant factor for all of the responses. For the optimization process, Response Surface Methodology (RSM) was used. The optimum baking conditions were determined as 5 min of baking time at 70% upper halogen lamp power, 50% lower halogen lamp power, and 20% microwave power. Breads baked at the optimum condition had comparable quality with conventionally baked ones. When halogen lamp-microwave combination oven was used, conventional baking time of breads was reduced by 60%. Artificial neural network models were developed for each of the quality parameters in order to observe the effects of the baking time and different oven conditions on the quality of the breads. High regression coefficients were calculated between the experimental data and predicted values showing that this method is capable in predicting quality parameters of breads during halogen lamp-microwave combination baking. In addition, the results were comparable to the RSM study.

The main objective of this study is to evaluate the effects of microwave frying process on the quality of potato slices and to optimize the process by using different statistical optimization techniques. Use of microwave frying for food products may be considered as a new way of improving the quality of the fried foods. In the first part of the study, the effects of microwaves on quality of fried potatoes (moisture content, oil content, color and hardness) were studied and the process was optimized by using Taguchi Technique. Microwave power level (400W, 550W and 700W), frying time (2.0, 2.5, 3.0 minutes) and oil type (sunflower, corn and hazelnut oil) were the parameters used in the study. Moisture content of potatoes decreased whereas oil content, hardness and &amp / #916 / E values of the potatoes increased with increasing frying time and microwave power level. The potatoes with the highest oil content were found to be the ones that were fried in the hazelnut oil. The optimum condition was found as frying at 550W microwave power level, for 2.5 minutes in sunflower oil. The potatoes that were fried at the optimum condition were determined to have lower oil contents compared to the ones fried conventionally.In the second part of the study, osmotic dehydration was applied prior to microwave frying process in order to reduce oil uptake and to evaluate the effect of osmotic dehydration with microwaves on quality of fried potatoes. The process was optimized by using both Taguchi Technique and Response Surface Methodology. Microwave power level (400W, 550W and 700W), frying time (1.5, 2.0, 2.5 minutes) and osmotic dehydration time (15, 30, 45 minutes) were the parameters used in the study. Osmotic dehydration treatment was conducted in a salt solution of 20 % (w/w) at 30oC. Moisture content decreased whereas oil content, hardness and &amp / #916 / E value of potatoes increased with increasing frying time and microwave power level. Dehydration of potatoes osmotically prior to frying reduced the oil content of fried potatoes. The optimum condition was found as frying at 400 W microwave power level for 1.5 min after 30 min of osmotic dehydration time according to Taguchi Technique. Microwave power level and frying time were the same as Taguchi Technique but osmotic dehydration time was 39 min for the optimum condition found using response surface methodology.

Orientador: Crispin Humberto Garcia-Cruz / Banca: Eleni Gomes / Banca: Ranulfo Monte Alegre / Banca: Vanildo Luiz Del Bianchi / Banca: Hamilton Cabral / Resumo: O principal produto da fermentação de açúcares por Zymomonas mobilis é o etanol quando glicose e frutose são utilizadas como fontes de carbono. Entretanto, quando sacarose é empregada na fermentação, o rendimento do etanol diminui devido à formação de subprodutos como levana, sorbitol, acetaldeído, ácido acético, pequenas quantidades de alguns álcoois superiores e fenol. A utilização de produtos agroindustriais, como o caldo e melaço de cana-deaçúcar, é uma alternativa para reduzir o custo final dos produtos de fermentação devido à disponibilidade de aquisição e composição química desses substratos. Este trabalho teve como objetivo utilizar substratos alternativos e otimizar as condições de fermentação para a produção de etanol, levana e sorbitol por Zymomonas mobilis CCT 4494. Também foi considerado o efeito da variação do substrato e de sais minerais adicionados nos meios de produção (sintético, caldo e melaços de cana-de-açúcar). Para a obtenção dos produtos de fermentação, foi aplicada a metodologia de superfície de resposta, seguindo um planejamento fatorial do tipo 27-2, de acordo com o modelo proposto por Box e Hunter, onde as variáveis independentes estudadas foram: pH inicial do meio de cultivo, temperatura de incubação, concentração do substrato e efeito da adição de KCl, K2SO4, MgSO4, CaCl2. Durante a realização das fermentações foi observado que a bactéria Zymomonas mobilis CCT 4494 se adaptou nos meios de fermentação contendo altas concentrações de sacarose e suportou a variação do pH e da temperatura de fermentação. O aumento da concentração da fonte de carbono favoreceu a formação dos produtos levana e etanol, entretanto, não houve produção de sorbitol. O meio sintético proporcionou maior rendimento de levana e etanol, enquanto que, os meios alternativos caldo e melaços de cana-de-açúcar... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The main product from fermentation of sugars by Zymomonas mobilis is ethanol when glucose and fructose are used as carbon sources. However, when sucrose is used in the fermentation medium, ethanol yield decreases due to the formation of by-products such as levan, sorbitol, acetaldehyde, acetic acid, small amounts of some superior alcohols and phenol. The use of agro industrial by products, such as sugarcane juice and molasses, is an alternative to reduce the final cost of fermentation products due to the constant availability and to the chemical composition of these by substrates. This study had the aim of using alternative substrates and of optimizing fermentation conditions for the production of ethanol, levan and sorbitol by Zymomonas mobilis CCT 4494. The effect of variation of substrate and mineral salts added to the production media (synthetic, sugarcane juice and molasses) was also considered. To obtain the fermentation products, response surface methodology was employed, following a 27-2 factorial planning, according to the model proposed by Box and Hunter, where the independent variables studied were: initial medium pH, incubation temperature, substrate concentration and effect of the addition of KCl, K2SO4, MgSO4, CaCl2. During the fermentations, it was noted that the bacteria Zymomonas mobilis CCT 4494 well adapted in the media containing high concentrations of sucrose and tolerated pH and temperature variations. The increase of carbon source concentration favored the formation of levan and ethanol, however, there was no sorbitol production. The synthetic medium offered higher levan and ethanol yield, whereas alternative media sugarcane juice and molasses, favored cellular growth. Among the independent variables analyzed with the best medium (synthetic) for biosynthesis of the biopolymer and ethanol, the ones that significantly (p<0.05) affected were KCl, K2SO4, CaCl2... (Complete abstract click electronic access below) / Doutor

abstract: In mixture-process variable experiments, it is common that the number of runs is greater than in mixture-only or process-variable experiments. These experiments have to estimate the parameters from the mixture components, process variables, and interactions of both variables. In some of these experiments there are variables that are hard to change or cannot be controlled under normal operating conditions. These situations often prohibit a complete randomization for the experimental runs due to practical and economical considerations. Furthermore, the process variables can be categorized into two types: variables that are controllable and directly affect the response, and variables that are uncontrollable and primarily affect the variability of the response. These uncontrollable variables are called noise factors and assumed controllable in a laboratory environment for the purpose of conducting experiments. The model containing both noise variables and control factors can be used to determine factor settings for the control factor that makes the response "robust" to the variability transmitted from the noise factors. These types of experiments can be analyzed in a model for the mean response and a model for the slope of the response within a split-plot structure. When considering the experimental designs, low prediction variances for the mean and slope model are desirable. The methods for the mixture-process variable designs with noise variables considering a restricted randomization are demonstrated and some mixture-process variable designs that are robust to the coefficients of interaction with noise variables are evaluated using fraction design space plots with the respect to the prediction variance properties. Finally, the G-optimal design that minimizes the maximum prediction variance over the entire design region is created using a genetic algorithm. / Dissertation/Thesis / Ph.D. Industrial Engineering 2010

Orientador: Marise Aparecida Rodrigues Pollonio / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-17T11:58:29Z (GMT). No. of bitstreams: 1 Cordeiro_Daniela_D.pdf: 9752486 bytes, checksum: 1343a77b6ab10d733d82260785e2a659 (MD5) Previous issue date: 2011 / Resumo: Atualmente os consumidores estão cada vez mais interessados no consumo de alimentos com apelos para a promoção da saúde. No desenvolvimento de produtos cárneos com características funcionais, os cereais, os quais possuem uma grande proporção de fibra insolúvel, têm vantagens fisiológicas e tecnológicas por serem constituídos principalmente de celulose. Destacam-se a capacidade de ligação de água e gordura e também a capacidade de reduzir custos de formulação. Sob este aspecto, este trabalho teve o objetivo de estudar e desenvolver formulações de produtos cárneos reestruturados empanados com alto teor de grão inteiro, farinhas, farelos e flocos de cereais integrais garantindo suas características tecnológicas e sensoriais. Primeiramente, foi realizada a seleção e avaliação das propriedades tecnológicas de diferentes cereais para combiná-los na forma de blends de cereais, através de analise físicoquímica e sensorial. A seguir, foi realizado o estudo do efeito da adição de diferentes blend de cereais (6% a 24%) em produto cárneo reestruturado empanado com avaliação das propriedades tecnológicas através da metodologia de superfície de resposta. Foram estudadas como variáveis respostas: umidade, absorção de óleo, textura, cor, bem como a qualidade sensorial geral e os atributos de aparência, cor interna e externa, textura e em especial crocância e sabor. Finalmente, foi estudada a influência dos métodos de cocção (fritura em óleo, forno convencional e forno microondas) sobre empanados de frango adicionados de sete tipos de cereais integrais. A seleção dos cereais e elaboração dos blends com sete tipos de cereais resultaram em teores adequados de proteínas (14,52%), lipídeos (10,39%) e carboidratos (62,72%) e um bom índice de capacidade de retenção de água (4,8). Nos produtos empanados a menor absorção de óleo foi para a formulação com 15% blends. A adição de até 24% de cereais integrais resultou num bom desempenho de textura e cor objetiva para os produtos empanados fritos. Em produtos empanados pré-fritos, houve um aumento na intensidade da cor amarela devido à adição dos blends de grãos e farinhas. Do ponto de vista sensorial os empanados adicionados de sete tipos de cereais integrais apresentar 97% de aceitação e 91% de intenção de compra pelo painel de consumidores, não diferindo da formulação controle. Os produtos submetidos ao forno microondas com 0% e 15% de cereais integrais, obtiveram os maiores porcentuais de umidade e lipídeos em comparação aos produtos cozidos em forno convencional, maior luminosidade e menor intensidade de vermelho, menor força de cisalhamento e as menores notas atribuídas pelos provadores em todos os atributos sensoriais, caracterizando um produto úmido, flácido, claro e sem crocância. Este trabalho permitiu a elaboração de um produto cárneo reestruturado empanado com alto teor de cereais integrais com boa aceitação sensorial, sendo necessários mais estudos para otimizar a substituição do processo de fritura por forneamento ou cocção em microondas / Abstract: Currently consumers are increasingly interested in food consumption with appeals for the promotion of health. In the development of meat products with functional features, cereals, which have a high proportion of insoluble fiber, have physiological and technological advantages because they are made primarily of cellulose. In this respect, this work was to study and develop formulations restructured breaded meat product with high content of whole grain, flour, bran and flakes, cereals and ensuring their sensory acceptance and technological. First, we performed the selection and evaluation of technological properties of different cereals and combine them in the form of blends of cereals, through physicalchemical analysis and sensory acceptance. Next, we performed a study of the effect of adding different blend of cereals (6% to 24%) in restructured breaded meat product and technological properties evaluation by response surface methodology. Were studied as variables response: moisture, oil absorption, texture, color sensory acceptance and appearance attributes, external and internal color, texture, flavor and crispness. Finally, we studied the influence of cooking methods (frying in oil, conventional oven and microwave oven) on breaded chicken added seven types of grains. The selection of grains and the blends with seven types of grain resulted in adequate levels of protein (14.52%), lipid (10.39%) and carbohydrate (62.72%) and a good index of holding capacity water (4.8). Breaded products the oil absorption was lower for the formulation with 15% blends. The addition of up to 24% of grains resulted in a good performance color and texture to the breaded products fried. In breaded pre-fried products, an increase in color saturation due to the addition of the blends of grains and flours. From the standpoint of the sensory the breaded products added seven types of grains presented 97% acceptance and 91% of purchase intention by the consumer panel did not differ from the control formulation. The products subject to the microwave oven at 0% and 15% whole grains, had the highest percentage of moisture and lipids in comparison to products cooked in conventional oven, greater brightness and low saturation yellow, lower shear force and lower scores by the judges in all sensory attributes, configuring in a product moist, flabby, clear and without crunchiness. This work allowed the preparation of a breaded restructured meat product with high content of whole grains with good sensory acceptance, more research is needed to optimize the replacement of the frying in the baking or microwave oven / Doutorado / Engenharia de Alimentos / Doutor em Tecnologia de Alimentos