Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1994. / Vita. Abstract. Includes bibliographical references (leaves 82-84). Also available via the Internet.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1964. / Typescript. Vita. Description based on print version record. Includes bibliographical references (leaves 188-192).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1957. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 349-353).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1951. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 96-98).

Thesis (M.S.)--University of Wisconsin--Madison. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 185-187).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1956. / Typescript. Abstracted in Dissertation abstracts, v. 16 (1956) no. 11, p. 2120. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 182-186).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1954. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 253-257).

A Chamomilla recutita L. é uma das plantas medicinais mais cultivadas no Brasil e no mundo. Os extratos da C. recutita são de interesse para as indústrias farmacêuticas e cosméticas, visto que estes apresentam atividades anti-inflamatória, antioxidante e adstringente. A ação terapêutica do extrato pode ser mais pronunciada que a ação terapêutica de um de seus ativos isolados. No entanto, a incorporação de um extrato em uma formulação pode ser difícil devido à baixa estabilidade dos extratos, bem como à possibilidade de gerarem instabilidade das formulações. Microencapsulando o extrato com um carreador é possível aumentar estabilidade do extrato quanto evitar instabilidade na formulação. Além disso, a microencapsulação é capaz de fornecer outras vantagens, como uma liberação controlada. Dois processos foram estudados como alternativas para a microencapsulação do óleo essencial e do extrato hidroalcoólico da C. recutita usando quitosana como carreador: o spray drying e o spray freeze drying. Planejamentos fatorais foram utilizados para determinar os fatores que mais influenciaram no diâmetro médio das micropartículas, eficiência de encapsulação e teor dos marcadores e rendimento do processo. A apigenina e a apigenina-7-glicosídeo foram usadas como marcadores do extrato hidroalcoólico e o óxido de bisabolol A foi usado como marcador do óleo essencial. Os processos de spray drying e spray freeze drying dos dois extratos foram otimizados e as micropartículas resultantes foram caracterizadas com relação ao diâmetro médio, rendimento do processo, teor e eficiência de encapsulação dos marcadores, atividade antioxidante in vitro, densidade, índice de Carr, fator de Hausner, umidade, morfologia, perfil de liberação n vitro e estabilidade. Os resultados mostraram que o processo de spray drying apresentou os melhores resultados para eficiência de encapsulação, com valores de aproximadamente 98%, 95% e 80% para apigenina, apigenina-7-glicosídeo e óxido de bisabolol A, respectivamente. As eficiências de encapsulação obtidas no processo de spray freeze drying foram de aproximadamente 59%, 58% e 38% para os mesmos marcadores, respectivamente. As micropartículas produzidas por spray freeze drying apresentaram formato irregular e poroso, enquanto as produzidas por spray drying apresentaram formato esférico e superfícies mais lisas, sem poros ou fissuras. Ao contrário do que ocorreu com o extrato hidroalcoólico, a perda do marcador do óleo foi elevada no processo de spray drying, com teor final de 35%. Os teores dos marcadores ficaram acima de 80% para o processo de spray freeze drying do óleo e acima de 90% para o extrato hidroalcoólico. As micropartículas produzidas por spray drying do extrato hidroalcoólico e do óleo e por spray freeze drying do extrato hidroalcoólico e do óleo apresentaram diâmetro médio de 5,1 ?m, 5,0 ?m, 31,0 ?m e 96,4 ?m, respectivamente. Ensaios de liberação in vitro mostraram que as micropartículas foram capazes de sustentar a liberação dos respectivos marcadores. Os estudos de permeação in vitro das micropartículas produzidas por spray drying do extrato hidroalcoólico também mostraram que estas foram capazes de sustentar a liberação. A microencapsulação proporcionou em todos os casos um aumento considerável da estabilidade. As micropartículas produzidas por spray drying do extrato hidroalcoólico apresentaram teores de marcadores no mínimo 50% maiores que o extrato puro após 90 dias. O spray freeze drying se mostrou como a melhor alternativa para produção de micropartículas de quitosana contendo o óleo essencial de C. recutita, enquanto o processo de spray drying se mostrou como uma ótima alternativa para microencapsulação do extrato hidroalcoólico da C. recutita. / Chamomilla recutita L. is one of the most cultivated medicinal plants in Brazil and around the world. Its extracts are important to both the pharmaceutical and cosmetics industries due to its therapeutic applications, such as an anti-inflammatory, antioxidant, and astringent. The therapeutic effects of an extract may be more pronounced than those of an isolated active compound. However, the incorporation of an extract in a formulation is difficult due to the low stability of extracts and the potential instabilities they may cause in formulations. Microencapsulating an extract in a carrier is a potential way of increasing the stability of an extract and avoiding instabilities in a formulation. Compound microencapsulation also brings other advantages, such as controlled release rates. Two processes were studied as alternatives to microencapsulating C. recutita essential oil and C. recutita hydroalcoholic extract using chitosan as a carrier: spray drying and spray freeze drying. Factorial designs were used to determine which process factors most influence the mean diameter, encapsulation efficiency and content of the chemical markers, and process yield. Apigenin and apigenin-7-glucoside were used as chemical markers for the hydroalcoholic extract and bisabolol oxide A was used as the chemical marker for the essential oil. The spray drying and spray freeze drying processes for both the oil and hydroalcoholic extract were optimized and the resulting microparticles were further characterized to determine mean diameter, process yield, marker encapsulation efficiency and content, in vitro antioxidant activity, density, Carr index, Hausner factor, water content, morphology, in vitro release profiles and stability. The results showed spray drying had the best encapsulation efficiency results, with about 98%, 95% e 80% of the apigenin, apigenin-7-glucoside and bisabolol oxide A content, respectively, inside the microparticles. The encapsulation efficiencies obtained in the spray freeze drying process were about 59%, 58% e 38% for the same chemical markers, respectively. Microparticles produced by spray freeze drying were irregular and porous, whereas microparticles produced by spray drying were spherical and fairly smooth, without porous or cracks. Contrary to what happened with the hydroalcoholic extract, oil marker content was low for spray dried microparticles, with final content at 35%. Chemical markers contents were above 80% for the oil and above 90% for the hydroalcoholic extract in spray freeze dried microparticles. Spray dried microparticles containing extract and oil and spray freeze dried microparticles containing extract and oil had mean diameter of 5.1 ?m, 5.0 ?m, 31.0 ?m and 96.4 ?m, respectively. In vitro release profiles showed all microparticles were able to sustain their respective marker release rates. In vitro permeation studies of spray dried microparticles containing hydroalcooholic extract also showed sustained release rates for the corresponding markers. Microencapsulation also provided considerable increase in C. recutita hydroalcoholic extract stability and C. recutita essential oil stability. After 90 days spray dried microparticles containing hydroalcoholic extract presented marker content 50% higher than the pure hydroalcoholic extract. Spray freeze drying was the best alternative to produce chitosan microparticles containing C. recutita essential oil, while spray drying was shown to be an excellent way to microencapsulate C. recutita hydroalcoholic extract in chitosan.

Orientador: Mauro Augusto Demarzo / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-21T13:52:31Z (GMT). No. of bitstreams: 1 Santos_SoniaRoseCostaAraujodos_M.pdf: 5172089 bytes, checksum: bd3d1a4e9a708a64ccb8763971508ae2 (MD5) Previous issue date: 2012 / Resumo: A variabilidade natural, a trabalhabilidade, as propriedades físicas e mecânicas, bem como características de utilidades estéticas e ambientais da madeira, encantam até hoje os pesquisadores no mundo. Ao longo dos séculos, a arte de secar a madeira em fornos foi sendo desenvolvida junto com as descobertas científicas e tecnológicas, com a associação de conhecimento elétrico e mecânico, chegando-se ao que temos hoje em dia. As razões fundamentais para secagem da madeira são: melhorar a estabilidade dimensional; redução de peso; possibilitar o processamento secundário; assegurar um melhor desempenho em uso de seus produtos. O objetivo deste trabalho é descrever a evolução dos equipamentos de secagem de madeira, considerando suas vantagens e desvantagens, por intermédio de visitas a empresas que possuem secadores, e entrevistar especialistas na área de secagem de madeira (nacionais e internacionais). Concluiu-se que os operadores são peças fundamentais para conduzir eficientemente o programa de secagem e interagir as variáveis do processo conseguindo um produto de qualidade para o uso estrutural ou manufaturado. E que, as propriedades físico-mecânicas da madeira devem ser consideradas para que seja alcançado um melhor desempenho do produto em uso / Abstract: The natural variability, the workability, the physical and mechanical properties as well as aesthetic characteristics and environmental utilities of the timber, enchant up today the researchers in the world. Over the centuries, the art of dry wood in stoves was being developed with the scientific and technological discoveries, with the combination of electrical and mechanical knowledge, reaching up to what we have today. The fundamental reasons for drying wood are: improved stability, weight reduction, enabling secondary processing; ensure better performance in use of its products. The objective of this paper is to describe the evolution of wood drying equipment considering its advantages and disadvantages, through visits to companies that have dryers, and interviewed experts in the field of wood drying (national and international). It was concluded that operators are fundamental to efficiently conduct the drying program and interacting process variables getting a quality product for structural use or manufactured. And that the physical and mechanical properties of the wood, should be considered, order to reach a better performance of the product in use / Mestrado / Estruturas / Mestre em Engenharia Civil

This thesis presents a numerical simulation study for the heat and mass transfer in- and out-side individual boards of a stack during kiln drying of wood and on the effect of side gaps between the boards. The objective is to optimize the drying process for efficiency and high quality products. A literature survey in the area is presented. The importance of the correct link between the transport processes in wood, and heat/mass transfer and fluid flow in the surrounding drying air is emphasized. Objectives, motivations and needs for the present study are also presented. This is followed by a detailed account of the governing equations, description of models, physical properties, and discretization and solution procedures used in the present study. A sample stack of planks has been used to evaluate the performance of various turbulence models and upwinding schemes of the CFX software developed for predicting the transport parameters in air. Given a typical stack set up for drying 105 x 105 mm western hemlock lumber, the effects of side gaps on surface coefficients are studied for different air velocities. An optimum gap size for maximum heat/mass transfer is suggested. The model developed for heat and mass transfer inside the wood is validated for a one dimensional case by comparing the numerical results with published results. The improved performance using a newly proposed relationship for the diffusivity of bound water has been demonstrated. Also a new relationship for the mass transfer boundary condition at the surfaces was proposed to incorporate the effect of the surface resistance. Relative effects of model unknowns in predicting the average moisture content and board center temperatures are discussed. A Fortran program was developed to solve the two-dimensional coupled heat and mass transfer equations inside the wood during the drying process. The model considers the changes in air temperature and humidity due to heat and mass transfer to and from the boards. The iterative SOR (Successive Over Relaxation) method was modified to increase accuracy and stability. Predictions for average and local moisture content are in good agreement with experiments. The effect of side gap on the drying process inside the wood was also examined. A plot of standard deviation of each board versus the board average moisture content is suggested for the judgement about the uniformity of the products. Results indicate that without using the extra gap size there exists a considerable difference between the maximum and minimum final average moisture content of the boards in each row. The first and last boards are usually over-dried. By using the previously suggested gap size the maximum difference of the final average moisture content is almost half the case without the extra gap. Average diffusion and surface coefficients are extracted from the experimental data of drying a stack without side gap. A software tool has been developed to solve the simple unsteady one-dimensional diffusion problem. Results are compared with experiments. The introduced method can be used to obtain the average diffusion and surface coefficients. / Graduate