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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

New Approaches To Desirability Functions By Nonsmooth And Nonlinear Optimization

Akteke-ozturk, Basak 01 July 2010 (has links) (PDF)
Desirability Functions continue to attract attention of scientists and researchers working in the area of multi-response optimization. There are many versions of such functions, differing mainly in formulations of individual and overall desirability functions. Derringer and Suich&rsquo / s desirability functions being used throughout this thesis are still the most preferred ones in practice and many other versions are derived from these. On the other hand, they have a drawback of containing nondifferentiable points and, hence, being nonsmooth. Current approaches to their optimization, which are based on derivative-free search techniques and modification of the functions by higher-degree polynomials, need to be diversified considering opportunities offered by modern nonlinear (global) optimization techniques and related softwares. A first motivation of this work is to develop a new efficient solution strategy for the maximization of overall desirability functions which comes out to be a nonsmooth composite constrained optimization problem by nonsmooth optimization methods. We observe that individual desirability functions used in practical computations are of mintype, a subclass of continuous selection functions. To reveal the mechanism that gives rise to a variation in the piecewise structure of desirability functions used in practice, we concentrate on a component-wise and generically piecewise min-type functions and, later on, max-type functions. It is our second motivation to analyze the structural and topological properties of desirability functions via piecewise max-type functions. In this thesis, we introduce adjusted desirability functions based on a reformulation of the individual desirability functions by a binary integer variable in order to deal with their piecewise definition. We define a constraint on the binary variable to obtain a continuous optimization problem of a nonlinear objective function including nondifferentiable points with the constraints of bounds for factors and responses. After describing the adjusted desirability functions on two well-known problems from the literature, we implement modified subgradient algorithm (MSG) in GAMS incorporating to CONOPT solver of GAMS software for solving the corresponding optimization problems. Moreover, BARON solver of GAMS is used to solve these optimization problems including adjusted desirability functions. Numerical applications with BARON show that this is a more efficient alternative solution strategy than the current desirability maximization approaches. We apply negative logarithm to the desirability functions and consider the properties of the resulting functions when they include more than one nondifferentiable point. With this approach we reveal the structure of the functions and employ the piecewise max-type functions as generalized desirability functions (GDFs). We introduce a suitable finite partitioning procedure of the individual functions over their compact and connected interval that yield our so-called GDFs. Hence, we construct GDFs with piecewise max-type functions which have efficient structural and topological properties. We present the structural stability, optimality and constraint qualification properties of GDFs using that of max-type functions. As a by-product of our GDF study, we develop a new method called two-stage (bilevel) approach for multi-objective optimization problems, based on a separation of the parameters: in y-space (optimization) and in x-space (representation). This approach is about calculating the factor variables corresponding to the ideal solutions of each individual functions in y, and then finding a set of compromised solutions in x by considering the convex hull of the ideal factors. This is an early attempt of a new multi-objective optimization method. Our first results show that global optimum of the overall problem may not be an element of the set of compromised solution. The overall problem in both x and y is extended to a new refined (disjunctive) generalized semi-infinite problem, herewith analyzing the stability and robustness properties of the objective function. In this course, we introduce the so-called robust optimization of desirability functions for the cases when response models contain uncertainty. Throughout this thesis, we give several modifications and extensions of the optimization problem of overall desirability functions.
62

Response distortion and social desirability in high-level executives

Schnure, Katherine Anne 17 November 2009 (has links)
The effect of Socially Desirable Responding (SDR) and response distortion on personality and selection measures has been debated for decades (Edwards, 1957b; Messick&Jackson, 1961; Morgeson et al., 2007, Ones, Viswesvaran,&Reiss, 1996). One area of this broad topic that has received less attention over the years has been the effectiveness of the scales used to measure SDR when evidence of potential response distortion is present. Using a MANOVA, this study found significant differences between job candidate and incumbent responses on the scales of the 16PF (Cattell&Cattell, 1995), which can be indicative of SDR (Rosse et al., 1998). However, no difference between the groups was found on the Impression Management scale used to measure SDR. Differences based on the job function of the respondents were also explored.
63

The good, the bad and the ugly : taste, domestic material culture and narratives of aesthetic judgement /

Woodward, Ian S. January 2001 (has links) (PDF)
Thesis (Ph. D.)--University of Queensland, 2002. / Includes bibliographical references.
64

"Men det får man väl inte säga i det här landet" : Ett experiment i politisk korrekthet / Political Correctness Gone Mad? : An Experiment in Social Desirability Bias

Floderus, Johan January 2015 (has links)
The aim of this study is to quantify the extent to which political correctness, understood as an implicit social convention of restraint on public expression, operates within a community. Due to a scarcity of prior experimental research in the area, a new method was developed for the purpose of the study. Using random selection, the treatment consists of exposing groups averaging 10 individuals to a survey on diversity and immigration matters. The effect is measured as the discrepancy in attitudes that is revealed between anonymous and non-anonymous responses to the treatment survey. Control groups are similarly exposed to a survey on traditional left-right matters. The discrepancies are then compared. The results are controlled for possible influence by factors including group size, sex ratio, and length of study. The general effect of the treatment is not statistically significant, possibly as a result of small sample size. Further analysis shows a significant positive correlation between the proportion of women and the extent of attitude discrepancy. On one interpretation, this means that women in the population are on average more responsive to political correctness than men. Due to the population’s skewed characteristics, the results are not generalised. Future researchers in the area are advised to draw their sample from a more representative population, to investigate additional subject matters and to collect more sophisticated data, in particular on the level of the individual.
65

Dynamic Interviewing Agents: Effects on Deception, Nonverbal Behavior, and Social Desirability

Schuetzler, Ryan M. January 2015 (has links)
Virtual humans and other virtual agents are becoming more common in our everyday lives. Whether in the form of phone-based personal assistants or automated customer service systems, these technologies have begun to touch more of our activities. This research aims to understand how this technology affects the way we interact with our computer systems. Using a chat bot, I studied the way a conversational computer system affects the way people interact with and perceive automated interviewing systems in two different contexts. Study 1 examines the impact of a conversational agent on behavior during deception. It found that a conversational agent can have a powerful impact on people's perception of the system, resulting in individuals viewing the system as much more engaging and human. The conversational agent further results in a suppression of deception-related cues consistent with a more human-like interaction. Study 2 focuses on the effect of a conversational agent on socially desirable responding. Results of this study indicate that a conversational agent increases social desirability when the topic of the interview is sensitive, but has no effect when the questions are non-sensitive. The results of these two studies indicate that a conversational agent can change the way people interact with a computer system in substantial and meaningful ways. These studies represent a step toward understanding how conversational agents can shape the way we view and interact with computers.
66

Soziale Erwünschtheit im Licht des Rational-Choice Ansatzes / Social Desirability in light of Rational Choice Theory

Lischewski, Julia 01 October 2014 (has links)
Soziale Erwünschtheit ist ein in der sozialwissenschaftlichen Forschung bekanntes Phänomen. Es beschreibt die Tendenz von Befragten sich gegenüber dem Interviewer, Dritten oder einer fiktiven Öffentlichkeit in einem „guten Licht“ zu präsentieren, insbesondere wenn sensible Themenbereiche angesprochen werden. Trotz nunmehr rund 60 Jahren Forschung ist es jedoch bisher nicht hinreichend gelungen, das Ausmaß dieser Verzerrung methodisch zu erfassen. Das Forschungsfeld zu diesem Phänomen ist breit, aber genau hier liegt die Problematik. Viele der Studien beschäftigen sich mit isolierten Effekten der sozial erwünschten Antwortverzerrung (SD-Bias), ohne dabei weitere wichtige Einflussfaktoren zu berücksichtigen. Darüber hinaus werden in den Studien sehr unterschiedliche Dimensionen und/oder Operationalisierungen des SD-Bias angesprochen. Aus diesem Grund besteht der erste Abschnitt der vorliegenden Dissertation aus einer systematischen Auseinandersetzung mit den verwendeten Begrifflichkeiten, Operationalisierungen und theoretischen Ansätze im Rahmen der SD-Forschung. Da die meißten theoretischen Argumente auf dem Rational-Choice Ansatz basieren oder auf ihn zurückgeführt werden können, konzentriert sich die vorliegende Arbeit auf soziale Erwünschtheit im Kontext der Rational-Choice Forschung. Bei genauer Auseinandersetzung mit der Thematik wird deutlich, dass das Phänomen der „sozialen Erwünschtheit“ eine Reihe unterschiedlicher Dimensionen umfasst, die berücksichtigt werden müssen, um eine präzise Begriffsklärung zu ermöglichen. Je nachdem, welcher Aspekt betrachtet wird, verändert sich der Blickwinkel, aus dem heraus soziale Erwünschtheit analysiert wird. Um die Vergleichbarkeit der Forschungsergebnisse zu gewährleisten, ist es jedoch notwendig, das zu untersuchende Phänomen „soziale Erwünschtheit“ und seine jeweiligen Dimensionen so exakt wie möglich zu beschreiben. Unter welchen Bedingungen tritt nun sozial erwünschtes Antwortverhalten nach dem Racional-Choice Ansatz auf? Dem Ansatz von Hartmut Esser und seiner Weiterentwicklung durch Volker Stocké nach kann das Anerkennungsbedürfnis als Persönlichkeitskonstrukt nur zu einer Antwortverzerrung führen, wenn der Befragten eine Norm als sozial erwünscht wahrnimmt und sich nicht in einer völlig anonymen Situation befindet. Es konnte gezeigt werden, dass die verschiedenen Ansätze theoretische Schwächen haben, die bei der Umsetzung und Interpretation von Ergebnissen berücksichtigt werden müssen. Der unpräzise Umgang mit Begriffen und theoretische Lücken sind dabei besonders gravierend. Auch die Skalen, die zur Kontrolle des SD-Bias genutzt werden, zeigen unsystematische Bezüge zu den Dimensionen der Erwünschtheit. Gerade bei der Erwünschtheitswahrnehmung und den Täuschungsskalen wird deutlich, dass beim exakten Umgang mit der Operationalisierung verschiedene Ebenen des SD-Bias sichtbar werden, die bei der Analyse berücksichtigt werden müssen. Bisher ist nicht geklärt, ob die verschiedenen Messungen tatsächlich ein und dasselbe Konstrukt erfassen und im Rahmen der Erklärung des SD-Bias funktional äquivalent einsetzbar sind. Um das Forschungsproblem näher zu bestimmen werden empirischen Abschnitt die Ergebnisse von drei empirischen Studien präsentiert. Zunächst wird im ersten Schritt mittels Faktorenanalyse gezeigt, dass die sogenannten Lügenskalen nicht die theoretischen Erwartungen erfüllen. Da in Bevölkerungsumfragen trotz dieser Schwächen, die Skalen immer noch Verwendung findet, wird im darauffolgenden Schritt der Erklärungsbeitrag dieser Skalen auf Vorurteilsmessungen untersucht. Auch hier zeigen sich fast ausschließlich unsystematische Ergebnisse, die im Zusammenhang mit aktuellen Forschungsergebnissen den Nutzen der Täuschungsskalen als einzige Determinante zur Kontrolle des SD-Bias in Frage stellen. Im dritten Schritt wurde deshalb der Beitrag umfassenderer Modelle zur Erklärung von Vorurteilen untersucht. Die Daten basieren auf einer Studierendstichprobe. Die Befunde lassen erkennen, dass keines der Modelle die gewünschte Stabilität erreichte und zum Teil sehr empfindlich auf kleine Veränderungen in der Operationalisierung reagierten. Im abschließenden Kapitel wird festgehalten, dass die unsystematische Forschungslage in Bezug auf den SD-Bias eine Ursache unklarer theoretischer Konzepte und Operationalisierung ist. Des weiteren wird klar, dass eine große Anzahl zusätzlicher Messungen notwendig wäre, um den SD-Bias in einer Umfrage korrekt zu kontrollieren. Da bisher jedoch nicht geklärt ist, unter welchen Bedingungen der SD-Bias ein ernsthaftes Problem, gibt es keine Rechtfertigung für den kosten- und zeitintensive Aufwand dieser Messung im Rahmen von Befragungen. Um das Zusammenspiel der einzelnen Komponenten und die Folgen ihrer Messung korrekt bewerten zu können, wäre ein umfassendes Forschungsprogramm dringend erforderlich.
67

Otimização Multiobjetivo em Problemas de Delineamento de Experimentos / Multiobjective Optimization in DOE Problems

Rodrigues, Douglas Miranda [UNESP] 10 October 2016 (has links)
Submitted by DOUGLAS MIRANDA RODRIGUES null (douglasnet@gmail.com) on 2016-10-20T13:35:28Z No. of bitstreams: 1 Dissertação - Douglas Miranda Rodrigues.pdf: 8525562 bytes, checksum: de3f28242f3d17929bb0eb8ddc912f55 (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-10-26T18:00:28Z (GMT) No. of bitstreams: 1 rodrigues_dm_me_guara.pdf: 8525562 bytes, checksum: de3f28242f3d17929bb0eb8ddc912f55 (MD5) / Made available in DSpace on 2016-10-26T18:00:28Z (GMT). No. of bitstreams: 1 rodrigues_dm_me_guara.pdf: 8525562 bytes, checksum: de3f28242f3d17929bb0eb8ddc912f55 (MD5) Previous issue date: 2016-10-10 / Em diversas áreas de trabalho, da Engenharia à Economia, os problemas se apresentam como sendo multiobjetivos, característica que torna complexa a tomada de decisão. Geralmente, estes objetivos são conflitantes e faz-se necessário o uso de técnicas de otimização para a obtenção de melhores resultados. Na presente dissertação serão estudados alguns métodos para a resolução destes problemas, com o objetivo de aplicar métodos de aglutinação em problemas de projetos de experimentos com múltiplas respostas. Deste modo, inicialmente foi realizada uma análise bibliométrica sobre os diferentes métodos utilizados para a resolução destes problemas. A partir disto, foi desenvolvida uma nova abordagem, utilizando a Programação por Compromisso (Compromise Programming – CP) e a Programação por Metas (Goal Programming – GP), bem como diferentes algoritmos (Gradiente Reduzido Generalizado – GRG e a metaheurística do software Optquest) que são usualmente adotados, com comparação de resultados e análise. De modo geral, esta nova proposta apresentou resultados melhores em relação à abordagem tradicional (desirability), qualificando este procedimento como uma alternativa na otimização de múltiplas respostas. / In many areas, from Engineering to Economics, problems present themselves as multiobjective, which makes a decision-making process complex. Generally, these are conflicting objectives, and optimization techniques are necessary to achieve better results. This paper applies agglutination methods in classical problems of design of experiments with multiple responses. A bibliometric analysis was made, and a new approach was developed, using Compromise Programming – CP and Goal Programming – GP, as well as two different algorithms (Generalized Reduced Gradient – GRG and Optquest’s software metaheuristics) with results comparison and analysis. The new proposal presented better results when compared to the traditional approach (desirability), qualifying this procedure as an alternative in multiple responses optimization.
68

Otimização Multiobjetivo em Problemas de Delineamento de Experimentos /

Rodrigues, Douglas Miranda January 2016 (has links)
Orientador: Fernando Augusto da Silva Marins / Resumo: Em diversas áreas de trabalho, da Engenharia à Economia, os problemas se apresentam como sendo multiobjetivos, característica que torna complexa a tomada de decisão. Geralmente, estes objetivos são conflitantes e faz-se necessário o uso de técnicas de otimização para a obtenção de melhores resultados. Na presente dissertação serão estudados alguns métodos para a resolução destes problemas, com o objetivo de aplicar métodos de aglutinação em problemas de projetos de experimentos com múltiplas respostas. Deste modo, inicialmente foi realizada uma análise bibliométrica sobre os diferentes métodos utilizados para a resolução destes problemas. A partir disto, foi desenvolvida uma nova abordagem, utilizando a Programação por Compromisso (Compromise Programming – CP) e a Programação por Metas (Goal Programming – GP), bem como diferentes algoritmos (Gradiente Reduzido Generalizado – GRG e a metaheurística do software Optquest) que são usualmente adotados, com comparação de resultados e análise. De modo geral, esta nova proposta apresentou resultados melhores em relação à abordagem tradicional (desirability), qualificando este procedimento como uma alternativa na otimização de múltiplas respostas. / Mestre
69

Caracterização e análise experimental do recobrimento de sementes de jambu (Spilanthes oleracea) em leito fluidizado / Characterization and experimental analysis of fluidized bed coating of jambu seeds (Spilanthes oleracea)

Costa, Cristiane Maria Leal 16 August 2018 (has links)
Orientadores: Sandra Cristina dos Santos Rocha, Lênio José Guerreiro de Faria / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-16T07:07:05Z (GMT). No. of bitstreams: 1 Costa_CristianeMariaLeal_D.pdf: 4893424 bytes, checksum: fe783f77ea1076a9111fde509073464c (MD5) Previous issue date: 2010 / Resumo: O jambu (Spilanthes oleracea) é uma planta herbácea nativa da região amazônica, da família Compositae, e tem seu cultivo difundido entre os pequenos produtores do nordeste do Estado do Pará. É uma hortaliça rica em elementos nutritivos como ferro, e ainda possui as vitaminas B1, B2, niacina, vitamina C, vitamina A e cálcio. Vale ressaltar que o jambu está atualmente despertando interesse científico e industrial devido as suas potencialidades econômicas. Nas últimas décadas, o desenvolvimento dos processos de recobrimento de partículas tem possibilitado a diversos setores da indústria e da agricultura a obtenção de resultados satisfatórios. As finalidades desses processos vão desde a correção de imperfeições estéticas e aumento de tamanho de partícula até o controle da liberação de substâncias químicas. O processo de recobrimento de sementes consiste em revestir totalmente a superfície da partícula com substâncias aderentes, que podem apresentar-se puras ou em mistura com materiais ativos e/ou inertes, melhorando a aparência, aumentando o tamanho e peso, facilitando a distribuição e o manuseio das sementes, especialmente aquelas muito pequenas e/ou irregulares. O objetivo deste trabalho foi efetuar a caracterização física e contribuir com o desenvolvimento do processo de recobrimento de sementes de jambu em leito fluidizado. Planejamento experimental e análise estatística dos resultados foram empregados para quantificar a influência da vazão da suspensão de recobrimento (Ws) e da vazão do ar de entrada (War), sobre a eficiência de recobrimento (?), crescimento relativo das partículas (?), perdas por elutriação (PE) e germinação (G). A estimativa do ponto ótimo de operação foi determinada em função das variáveis de entrada aplicando o conceito de desejabilidade global. Observou-se que as variáveis Ws e War, dentro da faixa estuda, influenciaram nas respostas consideradas. Dentre as condições estabelecidas neste trabalho, o valor ótimo da Função Desejabilidade é quando Ws é deslocada para o nível médio (6,4 mL/min) e War para o mínimo (0,89 kg/s), obtendo assim 45,1% para ?; 26,7% para ?; 82,4% para G e 46,5% para PE. Foram também determinadas as propriedades físicas e termodinâmicas das sementes de jambu in natura, submetidas ao processo de adsorção e dessorção de umidade nas temperaturas de 20, 30 e 40oC. Os dados experimentais foram avaliados usando seis diferentes modelos matemáticos. O calor isostérico e a entropia diferencial foram estimados através das relações de Clausius-Clapeyron e Gibbs-Helmholtz, respectivamente. O modelo GAB modificado apresentou melhor ajuste aos dados experimentais. Constatando-se um decréscimo gradual do calor molar de sorção com o aumento da umidade até valores próximos ao calor latente de vaporização da água pura, tornando-se assintótico quando o conteúdo de umidade de equilíbrio de 10%bs é alcançado. A teoria da compensação entalpiaentropia foi aplicada com sucesso às isotermas e indica que o mecanismo de sorção de umidade das sementes de jambu in natura pode ser considerado como controlado pela entalpia. Além disso, a análise do comportamento higroscópico das sementes recobertas mostrou claramente a proteção do recobrimento sobre as sementes de jambu, indicando que as sementes recobertas apresentam maior estabilidade higroscópica que as sementes nuas, e que o recobrimento atua como uma barreira à transferência de vapor d'água entre as sementes e o ambiente externo, controlando desta forma o processo de adsorção de umidade e favorecendo o manuseio e a armazenagem segura / Abstract: Jambu (Spilanthes oleracea) is an Amazon native herbaceous plant, from the Compositae family, and its crops are spread among small producers of the northeast of the State of Pará. It is a vegetable with many nutrients such as iron, vitamins B1, B2, C, A, niacine, and calcium. It is noteworthy that the jambu seeds present great scientific and industrial interest due o their economic potential. In the last decades, the development of particle coating and granulation processes has allowed several sectors of the industry and agriculture to reach satisfactory results. The objectives of these processes are correction of esthetic imperfections, the increase of particle size and the control of the release of chemicals. The coating process consists of a total overlay of the particle surface with adherent substances, which may be pure or mixed with active and/or inert materials. This process improves the appearance, handling and transport of the seeds, and it also increases size and weight of the particles, especially the tiny and/or irregular ones. The objectives of this work were to perform the physical characterization and to contribute to the development of the coating of jambu seeds in fluidized bed. The experimental design technique and the statistical analysis of the results were realized and the effects of independent variables coating suspension flow rate (Ws) and fluidization air flow rate (War) on the responses coating efficiency (?), particle relative growth (?), losses by elutriation (PE) and germination (G) were evaluated. The optimal operational point was determined as function of the entrance variables applying the concept of global desirability. Results showed that Ws and War, within the range studied, had significant influence on the responses considered. Among the conditions established in this work, the optimal value of the Desirability Function is obtained when Ws is displaced to the average level (6,4 mL/min) and War to the minimum (0.89 kg/s), resulting in: 45.1% for ?, 26.7% for ?, 82.4% for G and 46.5% for PE. Experimental data on the sorption isotherms of jambu seeds were used to determine thermodynamic functions at 20, 30 and 40oC. Six mathematical models were applied to analyze the experimental data. The modified GAB model showed the best fitting to the experimental data. The desorption and adsorption isosteric heat and differential entropy were determined by applying Clausius-Clapeyron and Gibbs-Helmholtz equation, respectively. The moisture vaporization heat in jambu seeds decreased with increase in moisture content and approached the latent heat of pure water and became asymptotic as moisture content of 10% (b.d) was approached. The enthalpy-entropy compensation theory was applied to the isotherms, indicating that they are enthalpy-controlled. In addition, analysis of the hygroscopic behavior of the coated seeds showed a clear protective coating on the seeds of jambu, and indicated that the coated seeds adsorbed less moisture than jambu seeds in natura, showing that the coating layer acts as a barrier to the transfer of water vapor between the seeds and the external environment, thus controlling the process of moisture adsorption and promoting the safe handling and storage / Doutorado / Engenharia de Processos / Doutor em Engenharia Química
70

Obtenção de produtos a partir das folhas de Copaifera langsdorffii Desf.: otimização da extração e secagem em spray dryer utilizando planejamentos experimentais / Obtainment of products from Copaifera langsdorffii Desf. leaves: extraction and spray drying optimization by experimental designs

Ana Rita de Mello Costa-Machado 08 December 2011 (has links)
A planta brasileira Copaifera sp. é uma árvore cujo óleo é tradicionalmente utilizado pela população principalmente como antiinflamatório, analgésico e relaxante muscular justificando o grande interesse científico em seu estudo. Entretanto, estudos tecnológicos, fitoquímicos e biológicos sobre suas folhas são escassos. Assim, este trabalho propôs estudar e otimizar o processo extrativo a partir das folhas de Copaifera langsdorffii Desf., além de determinar as melhores condições de secagem em spray dryer, já que formas farmacêuticas sólidas são mais interessantes do ponto de vista mercadológico e farmacotécnico e ambas as estapas são fundamentais para o desenvolvimento de um futuro medicamento fitoterápico. As condições ótimas de extração e secagem em spray dryer foram obtidas através de diversos planejamentos experimentais como o planejamento Box-Behnken, a inclinação ascendente e a função desejabilidade. Para obtenção do extrato líquido através do processo de maceração dinâmica, objetivou-se maximizar as seguintes respostas: teor de sólidos solúveis e flavonóides totais e dos marcadores químicos, quercetrina e afzelina. As condições ótimas de extração encontradas foram: massa de planta de 41 g, proporção etanol/ água de 79°GL, tempo de extração de 1 h, temperatura de extração de 25°C e velocidade de agitação de 600 rpm. No estudo do processo de secagem em spray dryer, foi realizado inicialmente um teste preliminar onde oito diferentes excipientes disponíveis foram estudados quanto às caracterísitcas físico-químicas entre elas fluidez, compactação e degradação dos marcadores químicos. As condições do equipamento foram: bico atomizador duplo fluido pneumático com orifício de abertura de 1,2 mm que operou com vazão de ar de 40 L/min e pressão de 5,0 bar; vazão do gás de secagem de 0,6 m3/min; temperatura de saída (Ts) de 80°C e fluxo da amostra (Ws) de 5,0 g/min. A proporção sólidos do extrato líquido de C. langsdoffii: excipiente foi de 3:1. Entre os excipientes estudados, o manitol foi o que forneceu o extrato seco de C. langsdorffii com melhores características físicas e físico-químicas e, por isso foi utilizado no estudo seguinte, o planejamento Box-Behnken cujas variáveis estudadas foram concentração da amostra (Cs), fluxo da amostra (Ws) e temperatura de saída (Ts). Foram avaliadas nove respostas das quais: densidade compactada, ângulo de repouso, índice de Carr, umidade absorvida, rendimento, eficiência de secagem, degradação de flavonóides totais, quercetrina e afzelina. Para obter a condição de secagem em que as nove respostas apresentassem valores satisfatórios, utilizou-se a função desejabilidade. Assim, as condições de secagem para se obter o extrato seco de C. langsdorffii com boas características foram: concentração da amostra de 20,7% m/m, fluxo da amostra de 5 g/min e temperatura de saída de 80°C. Como resultado final deste trabalho, obteve-se um extrato líquido de C. langsdorffii otimizado com teores máximos de sólidos solúveis e dos marcadores químicos e um extrato seco com propriedades físicas, físico-químicas e farmacotécnicas adequadas para a obtenção de formas farmacêuticas sólidas. / The Brazilian plant Copaifera sp. is a tree the oil of which is widely used in popular medicine as an anti-inflammatory, analgesic and muscle relaxant, consequently it is the subject of huge scientific interest. However, technological, phytochemical and biological studies regarding its leaves are rare. Thus, this work aimed to study and optimize the extraction process from Copaifera langsdorffii Desf. leaves, as well as to determine the best conditions for the spray drying process, since pharmaceutical solid forms are more marketable and of pharmacotechnical interests, with both steps being fundamental to the development of a future phytomedicine. The best extraction and spray drying conditions were guided by several experimental designs such as the Box-Behnken, the steepest ascent and the desirability function. From liquid extract achievement through dynamic maceration, the purpose was to maximize the following responses: soluble solids and total flavonoids contents and the chemical markers, quercetrin and afzelin contents. The best extraction conditions found were: plant mass of 41 g, ethanol/water proportion of 79°GL, extraction time of 1 h, extraction temperature of 25°C and stirring speed of 600 rpm. In the spray drying study, a preliminary test was accomplished, where eight different excipients were studied with regard to the physicochemical features such as flowability, compaction and chemical marker degradation. The equipment conditions were: a two-fluid pneumatic spray nozzle with an inlet orifice diameter of 1.2 mm that operated on 40 L/min air rate and 5 bar pressure; 0.6 m3/min drying air rate; 80°C outlet temperature (Ts) and 5.0 g/min sample feed rate (Ws). The proportion of C. langsdorffii liquid extract solids content: excipient was 3:1. Among the excipients studied, mannitol provided the best physicochemical feature for C. langsdorffii dried extract, therefore it was used in the following test, the Box-Behnken design, where the studied variables were sample concentration (Cs), sample feed rate (Ws) and outlet temperature (Ts). Nine responses were evaluated: tapped density, angle of repose, Carr index, humidity absorption, yield, drying efficiency, total flavonoids and quercetrin and afzelin degradation. To obtain the drying conditions where the nine responses presented satisfactory values, the desirability function was used. Thus, the drying conditions to obtain a dried extract with good physicochemical features were: sample concentration of 20.7% w/w, sample feed rate of 5.0 g/min and outlet temperature of 80°C. As a final result of this work, an optimized C. langsdorffii liquid extract presenting maximum soluble solids and chemical markers contents and a dried extract presenting the appropriate physical, physicochemical and pharmacotechnical properties to produce pharmaceutical solid forms were obtained.

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