Orientador: Wesley Jorge Freire / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola / Made available in DSpace on 2018-08-10T15:14:00Z (GMT). No. of bitstreams: 1 Milani_AnaPauladaSilva_D.pdf: 3076744 bytes, checksum: 90564ecb142bc32caa265925c34b592f (MD5) Previous issue date: 2008 / Resumo: No Brasil existem sérios problemas ambientais no que se refere à constante geração de resíduos agroindustriais e a falta de tecnologias e materiais de construção energeticamente eficientes. Buscando um material alternativo de construção que minimize esta degradação ambiental e reduza os custos energéticos do produto final, no presente trabalho foram pesquisadas diferentes misturas de solo-cimento-cinza de casca de arroz, de forma a resgatar o uso da terra crua como elemento construtivo sustentável e proporcionar à cinza residual de casca de arroz uma destinação final adequada. O principal objetivo da pesquisa foi estudar as características de diferentes misturas de solo-cimento-cinza priorizando a máxima incorporação de cinza residual aliado ao mínimo consumo do estabilizante cimento para obtenção de um material que atenda às solicitações usuais de paredes de vedação, bem como submeter o material solo-cimento-cinza a avaliações de desempenho na construção de paredes monolíticas para habitações, quer sejam urbanas ou rurais. Para tal, foram realizados o peneiramento da cinza de casca de arroz e o estudo de dosagem das misturas de solo-cimento-cinza através de ensaios de compactação normal de Proctor e de ensaios de compressão simples e de ultra-som. A partir deste estudo preliminar, as misturas de solo-cimento-cinza que melhores resultados apresentaram foram utilizadas para a determinação de suas outras características físicas e mecânicas sendo, posteriormente, selecionadas para a construção de uma edificação protótipo, cujos desempenho estrutural, desempenho térmico e desempenho físico das paredes monolíticas de solo-cimento-cinza de casca de arroz foram avaliados e analisados tecnicamente. Pôde-se concluir que o solo arenoso, quando substituído por 7,5% de cinza (em massa) e estabilizado com 10% de cimento, apresentou-se como um material alternativo de construção de boa qualidade, de baixo custo e com potencialidade para construção de componentes construtivos em habitações de interesse social / Abstract: The environmental concern related to the indiscriminate extraction of Brazilian natural resources and the ceaseless agricultural and industrial waste generation became a serious problem demanding for a quick solution. So this work was done in order to minimize the environment degradation by using rice husk ash added to mixtures of soil and cement aiming at the obtainment of an alternative construction material. For this purpose, a sandy soil was treated with different amounts of cement and rice husk ash before being submitted to physical and mechanical tests. The rice husk ash preparation consisted of grinding and sieving later followed by physical characteristics determination in laboratory conditions. The different mixtures of soil, cement and rice husk ash were firstly tested for compaction and unconfined compression and afterwards by many others physical and mechanical tests in order to determine their main characteristics. The soil-cement-rice husk ash mixture presenting the best results in terms of mechanical strength, water absorption and ultrasonic wave velocity was utilized for the construction of a prototype building whose structural, thermic and physical performances of the soil-cement-rice husk ash monolithic walls were technically analysed. The results showed that the sandy soil partially substituted by 7.5% of rice husk ash and stabilized with 10% of cement was the best treatment, pointing out its promising use as an alternative material for rural construction / Doutorado / Construções Rurais e Ambiencia / Doutor em Engenharia Agrícola

Orientador: Ulf Schuchardt / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-17T06:24:21Z (GMT). No. of bitstreams: 1 Teixeira_Sergio_D.pdf: 1780552 bytes, checksum: d5f0a33d2cb14fcc39d1286a8b7c19d6 (MD5) Previous issue date: 2006 / Resumo: Derivados de óleos vegetais foram preparados utilizando-se catalisadores homogêneos e heterogêneos. Em quatro diferentes estudos foram produzidos epóxidos, hidroxi-éteres vicinais, antioxidantes e surfactantes. Os epóxidos graxos foram preparados a partir de oleato de metila, bem como óleo de soja e seus ésteres metílicos através de três métodos: (i) químio-enzimático; (ii) convencional (geração in situ de um perácido de cadeia curta) e (iii) catalítico, com peróxido de hidrogênio na presença de aluminas. Em todos os sistemas foram obtidas conversões > 90 % e seletividades > 95 %. Os rendimentos em epóxidos do sistema envolvendo as aluminas foram semelhantes aos obtidos com perácidos de cadeia curta. A alumina mais ativa foi utilizada em quatro epoxidações sem perdas significativas na atividade. Os experimentos de abertura de anéis oxirânicos presentes em ésteres graxos epoxidados, para a obtenção de hidroxi-éteres vicinais, foram realizados com metanol, isopropanol e etilenoglicol. Nos experimentos com isopropanol, o catalisador mais ativo - argila montmorilonita modificada com o ácido dodecatungstofosfórico - permitiu conversão > 98 % e seletividade de 95 % para os produtos de interesse. Nas reações com etilenoglicol foram obtidos produtos com elevadas massas molares, resultantes da formação de dímeros, trímeros e de outras espécies oligoméricas. Em outra parte do estudo foram sintetizados antioxidantes lipofílicos a partir de ácido ascórbico e compostos graxos, como estearato de vinila, oleato de metila e ácido oléico. Nas reações catalisadas por preparados enzimáticos, o substrato vinílico mostrou-se o mais eficiente, levando a rendimentos próximos de 75 % para o ascorbato nas condições otimizadas. O procedimento adotado mostrou-se inadequado para a obtenção de ascorbatos insaturados (rendimentos abaixo de 25 %). Na parte final, é descrita a preparação de uma betaína a partir de óleo de babaçu, com o objetivo de avaliar a utilização desse insumo em substituição aos óleos de coco e de palmiste, normalmente utilizados como matéria-prima na produção de betaínas. A metodologia empregada mostrou-se adequada e o produto foi obtido como uma solução aquosa com concentração próxima de 30 % (m/m). / Abstract: Vegetable oil derivatives were prepared using homogeneous and heterogeneous catalysts. In four different studies, epoxides, vicinal hydroxyl-ethers, antioxidants and surfactants were obtained. The fatty epoxides were prepared from methyl oleate, as well as soybean oil and its methyl esters mixture, using three methods: (i) chemo-enzymatic; (ii) conventional (short chain peracid in situ generation) and (iii) catalytic, with hydrogen peroxide in presence of aluminas. Conversion > 90 % and selectivity > 95 % were obtained for all the systems. For the system with alumina, epoxide yields were next to the obtained with short chain peracids. The most active alumina could be used in four epoxidations without significant reactivity loss. The ring opening reactions using epoxidized fatty esters were carried out with methanol, isopropanol and ethylene glycol. With isopropanol, the more active catalyst - K10 montmorillonite clay modified with dodecatungstophosphoric acid - allowed a conversion > 98 % and selectivity of 97 %. High molar mass products were obtained in the reactions with ethylene glycol; such products result from the formation of dimers and trimers, among other oligomeric species. In another part of the work, lipophilic antioxidants were synthesized from ascorbic acid and fatty compounds, such as vinyl stearate, methyl oleate and oleic acid, using enzymatic catalysts. The vinylic substrate was the more efficient, allowing 75 % of ascorbate yield. The employed procedures were unsuitable for the production of unsatured ascorbates (yields > 25 %). The final part describes the preparation of a betaine from babaçu oil. The aim was to evaluate this oil as a substitute for coconut and palmiste oils, usually used for betaine production. The methodology was suitable and the product was obtained as an aqueous solution (30 % m/m). / Doutorado / Quimica Inorganica / Doutor em Ciências

Orientadores: Eder Lima de Albuquerque, Cecília Amélia de Carvalho Zavaglia / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-17T18:28:48Z (GMT). No. of bitstreams: 1 Santos_NubiaSuelySilva_D.pdf: 4363251 bytes, checksum: 213063c74cfba9cbb1d694d631c78ebf (MD5) Previous issue date: 2010 / Resumo: Neste trabalho foram elaborados compósitos poliméricos reforçados com fibras longas e contínuas de miriti, com frações de volume de fibra de 10, 20 e 30%. A fibra de miriti é proveniente do pecíolo da palmeira de burtiti (Mauritia flexuosa L.), palmeira abundante na região amazônica, utilizada na alimentação e na produção de artesanato popular. As características físicas, morfológicas, microestruturais e mecânicas da fibra de miriti, são estudadas. Para a elaboração dos compósitos as fibras receberam tratamento superficial com solução alcalina, a 5%, e a resina de poliéster insaturado foi utilizada como matriz. Foram elaborados neste trabalho, compósitos com as fibras de miriti alinhadas longitudinalmente, chamados de compósitos unidirecionais (UD), e compósitos com fibras de miriti em duas direções ortogonais entre si, chamados de compósitos bi-direcionais (2D). Os compósitos foram consolidados sob pressão, e em seguida foi conduzido o processo de pós-cura a 60 C de temperatura. A caracterização mecânica dos compósitos foi feita sob carregamento de tração (norma ASTM D 638), e sob carregamento de flexão (norma ASTM D 790). Os corpos de prova foram retirados das placas moldadas, e 5 corpos de prova de cada compósito foram submetidos aos ensaios mecânicos. Os resultados obtidos após os ensaios de tração e flexão dos compósitos, mostram a influência da adição de fibras no comportamento mecânico dos compósitos, assim como a influência da orientação das fibras no compósito. A verificação teórica dos resultados experimentais é conduzida para os compósitos unidirecionais testados sob tração, e os valores teóricos foram obtidos por meio da regra da mistura, da teoria de micromecânica dos compósitos. Aspectos macroscópicos e microscópicos da fratura após os ensaios mecânicos foram observados e mostram região de dano e interface fibra-matriz, respectivamente. Os resultados mostram que a adição de fibras à matriz de resina poliéster insaturado, foi, de modo geral, favorável às propriedades mecânicas dos compósitos. A melhor performance mecânica foi obtida pelo compósito unidirecional com 30% em fração de volume de fibras de miriti, testados na direção do carregamento. Para os compósitos bi-direcionais (2D), a adição de fração em volume de fibras somente foi favorável para as propriedades mecânicas sob tração, sendo pouco significativa para os resultados das propriedades sob flexão. Segundo a verificação teórica feita para os resultados experimentais, acima de 25% de adição de fração em volume de fibras, começa a haver sinergia entre os componentes do compósito, evidenciando o efeito reforçante das fibras de miriti / Abstract: In this work continuous miriti fiber reinforced unsaturated polyester matrix composites were elaborated, with 10, 20 and 30% of fiber volume fraction. Miriti fibers are extracted from petiole of buriti palm (Mauritia flexuosa L.), which is a typical specie that grow in Amazonian region, used as food and handicrafts. Physical, morphological, microstructural and mechanical characteristics of miriti fibers were investigated. Treated fibers with a sodium hydroxide solution (5%) were used to elaborate composites in this work. Composites with continuous miriti fibers aligned on unidirectional direction, named as unidirectional composites (UD), and composites with continuous miriti fibers aligned in orthogonal directions, named as bi-directional (2D) composites were elaborated. The composites were consolidated under pressure and a post-cure process was conducted at a 60 C temperature. Mechanical characterization of composites was made under tensile load (ASTM D 638), and under bending load (ASTM D 790). Specimens were taken from molded plates and five specimens of each composite were subjected to mechanical tests. Results obtained after the mechanical tests show the influence of fiber addition on mechanical behavior of composites, as well as the influence of fiber orientation. Theoretical verification of experimental results is conducted for unidirectional composites tested under tension, and the theoretical values were obtained by the mixture rule of micromechanical theory of composites. Macroscopic and microscopic aspects of fracture after the mechanical tests are observed and show the region of damage and fiber-matrix interface, respectively. Results obtained showed that fiber addition on unsaturated polyester resin was favorable to the mechanical properties of composites. The best mechanical performance was obtained by unidirectional composite with 30% in volume fraction of miriti fibers tested on the direction of loading. For 2D composites the addition of fiber volume fraction was only favorable for mechanical properties under tensile load, with little effect on bending properties. According to theoretical verification conducted to the experimental results, more than 25% of fiber volume fraction of miriti fibers, begins to have synergy between the components of the composite, which shows the miriti fibers / Doutorado / Mecanica dos Sólidos e Projeto Mecanico / Doutor em Engenharia Mecânica

Made available in DSpace on 2014-10-09T12:41:28Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:03:22Z (GMT). No. of bitstreams: 0 / Sistemas de liberação controlada vêm sendo cada vez mais utilizados em diferentes áreas tendo em vista sua aplicabilidade que os tornam uma tecnologia capaz de atender as necessidades econômicas e ambientais uma vez que permitem a utilização de princípios ativos em quantidades precisas e apenas nos locais desejados. Dentre a diversidade de opções de matrizes utilizadas nesses sistemas o poli(álcool vinílico) tem sido bastante empregado e pode ser obtido pela técnica de ciclos térmicos. Azadiractina, um princípio ativo encontrado em óleo de semente de Nim tem sido descrita como repelente de diferentes tipos de insetos e apresenta grande aplicabilidade na agricultura. Com base nas propriedades desse composto, propôs-se o desenvolvimento de um sistema de liberação controlada para combate a pulgas Ctenocephalides felis felis. No presente trabalho, foram realizadas caracterizações físico-químicas das matrizes e dispositivos através de ensaios de fração gel, intumescimento, calorimetria exploratória diferencial e microscopia eletrônica de varredura e caracterizações biológicas quanto à citotoxicidade do óleo de Nim, matrizes e dispositivos e bioensaio para análise do comportamento das pulgas na presença do óleo de Nim. As caracterizações físico-químicas permitiram a escolha da matriz mais adequada para o desenvolvimento do dispositivo. As caracterizações biológicas demonstraram ausência de citotoxicidade do óleo de Nim, das matrizes e dos dispositivos e o bioensaio resultou em 40% de mortalidade das pulgas testadas. Na cinética de liberação, verificou-se que todos os agentes encapsulantes utilizados permitiram a liberação de princípios ativos do óleo de Nim. / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Orientador: Marco Aurelio De Paoli / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-15T06:04:56Z (GMT). No. of bitstreams: 1 Mano_BarbaraIriaSilva_M.pdf: 2057680 bytes, checksum: 859baca955b2cb03248e636dd9c52e70 (MD5) Previous issue date: 2009 / Resumo: O desenvolvimento de materiais formulados com fibras vegetais é interessante para países muito ricos em recursos naturais, como o Brasil, pois se promove o desenvolvimento tecnológico aproveitando-se matéria-prima nacional, dando-lhe finalidades mais nobres. A aplicação de fibras vegetais curtas em compósitos com matrizes poliméricas tem recebido crescente atenção, pois as fibras melhoram as propriedades mecânicas dos polímeros e tem potencial para substituir fibras inorgânicas, em especial a fibra de vidro, com uma série de vantagens que incluem a leveza, biodegradabilidade e menor abrasividade aos equipamentos de processamento. Neste trabalho, estudou-se a incorporação de fibras de curauá em polipropileno, por extrusão seguida de injeção, variando-se a rotação das roscas da extrusora dupla-rosca, o teor de fibras e de agente de acoplamento. Os compósitos processados a 300 rpm e contendo 20 wt% de fibras e 2 wt% de agente de acoplamento apresentaram as melhores propriedades mecânicas nos ensaios mecânicos de tração, flexão e impacto. As propriedades não superam as dos compósitos com fibras de vidro, mas são competitivas. A degradação e estabilização foram avaliadas pelo ensaio de envelhecimento ambiental de amostras de polipropileno e compósitos com e sem estabilizantes comerciais, para analisar o efeito de cada componente sobre a degradação do sistema. Enquanto o agente de acoplamento atuou como pró-degradante, as fibras atuaram como bloqueadores da radiação e protegeram o compósito do envelhecimento. Essa parte do trabalho foi importante para definir a correta aditivação dos compósitos. Os estabilizantes escolhidos foram satisfatórios na prevenção do envelhecimento das amostras e reduziram o efeito pró-degradante do agente de acoplamento. A partir desses resultados, é possível definir a formulação adequada para cada aplicação específica. / Abstract: The development of materials formulated with vegetal fibers is interesting for countries with high availability of natural resources, like Brazil, due to the possibility of promoting technological development using their own raw materials. The use of short vegetal fibers composites with polymeric matrices have been receiving attention due to the fact that the fibers increase the mechanical properties of the polymers and have potential to substitute inorganic fibers, in special glass fiber, with many advantages that include being lighter, biodegradable and less abrasive to the processing equipments. In this work, the incorporation of curauá fibers on polypropylene matrix by extrusion and injection molding was studied, testing different screw rotation speed in the twin-screw extruder, the fiber and the coupling agent content. The composites prepared with the rotation of 300 rpm, 20 wt% of fiber and 2 wt% of coupling agent showed the best mechanical properties evaluated in tensile, flexural and impact tests This mechanical performance does not overcome the properties of the composites reinforced with glass fibers, but are competitive with them. The degradation and stabilization were evaluated through natural ageing of samples of PP and composites with and without commercial stabilizers, in order to analyze the effect of each component on the degradation of the system. While the coupling agent worked prodegrading the systems, the fibers had a screening effect and protected them from the ageing. This part of the work was important to choose suitable additivation for the composites. The stabilizers chosen for the formulation worked satisfactorily in preventing the ageing of the samples and reduced the prodegrading effect of the coupling agent. Based on these results, it is possible to define a suitable formulation of the composites for each final application. / Mestrado / Quimica Inorganica / Mestre em Química

Orientador : Wesley Jorge Freire / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola / Made available in DSpace on 2018-08-04T02:41:28Z (GMT). No. of bitstreams: 1 Milani_AnaPauladaSilva_M.pdf: 1388298 bytes, checksum: 29b07ee608ddbe854bae23bf9715ab1a (MD5) Previous issue date: 2005 / Resumo: No Brasil existem sérios problemas ambientais no que se refere à extração indiscriminada de recursos naturais e à constante geração de resíduos agroindustriais. Buscando soluções que minimizem esta degradação ambiental, o presente trabalho pesquisou misturas de solo + aglomerante mineral + resíduo agroindustrial, sendo utilizado, como recurso natural, a terra; como estabilizante, o cimento e a cal; e, como resíduo agroindustrial, a casca de arroz. O principal objetivo da pesquisa foi estudar os efeitos da adição de combinações de cimentocasca de arroz e de cal-casca de arroz nas propriedades físico-mecânicas de um solo predominantemente arenoso e outro solo predominantemente argiloso, bem como avaliar a viabilidade técnica da confecção de tijolos de solo-cimento-casca de arroz e solo-cal-casca de arroz. Para tal, foram realizados o fracionamento, peneiramento e pré-tratamento (em solução de cal) da casca de arroz; estudo de dosagem das misturas de solo-aglomerante-casca de arroz através de ensaios de compactação normal de Proctor e ensaio de compressão simples. A partir deste estudo preliminar, as misturas de solo-aglomerante-casca de arroz que melhores resultados apresentaram em termos de desempenho mecânico foram utilizadas para a confecção de corpos-de-prova e tijolos para posterior caracterização físico-mecânica. A avaliação dos corpo-de-prova de solo-aglomerante-casca de arroz consistiu na aplicação dos ensaios de compressão simples, de tração na compressão diametral, aos 7 e 28 dias, de absorção d¿água e de ultra-som. Já os tijolos de solo-aglomerante-casca de arroz foram submetidos aos ensaios de compressão simples aos 7, 28 e 60 dias, de absorção de água e de ultra-som. Depois de determinadas e estatisticamente analisadas as principais características físicas e mecânicas das misturas de solo-aglomerante-casca de arroz, pôde-se concluir que o solo arenoso, adicionado de 12% de combinações de cimento-casca de arroz, apresentou-se como promissor material para utilização na fabricação de tijolos prensados a serem utilizados em construções e instalações rurais / Abstract: The environmental concern related to the indiscriminate extraction of Brazilian natural resources and the ceaseless agricultural and industrial waste generation became a serious problem demanding for a quick solution. So this work was done in order to minimize the environment degradation by using rice husk added to mixtures of soil and cement or lime aiming at the obtainment of an alternative construction material. For this purpose, two different types of soil, a sandy soil and a clayey one, were treated with different amounts of cement, lime and rice husk before being submitted to physical and mechanical tests. The rice husk preparation consisted of grinding, sieving, and pre-treatment with lime solution followed by physical analysis in laboratory conditions. The different mixtures of soil, cement, lime and rice husk were tested for compaction and unconfined compression. The specimens molded according to the treatments applied to the mixtures were subsequently submitted to compression testing at 7 and 28 days old as well as to water absorption and to ultrasonic pulse velocity tests. The soil-cement/lime-rice husk mixtures presenting the best results in terms of mechanical strength were utilized for specimen molding and brick manufacturing, the specimens being tested for both the compression and the splitting tensile strength at 7 and 28 days old as well as to water absorption and ultrasonic pulse velocity tests. On the other hand, the bricks were tested to compression at 7, 28 and 60 days old, to water absorption and to ultrasonic pulse velocity. The obtained data were then statically analyzed and the results showed that the sandy soil added of 12% of the cement and rice husk combination was the best treatment in terms of physical and mechanical properties, pointing out its promising use as an alternative material for brick manufacture to be used in rural construction / Mestrado / Construções Rurais e Ambiencia / Mestre em Engenharia Agrícola

Doctor of Philosophy / Department of Food, Nutrition, Dietetics and Health / Tandalayo Kidd / Objective: The purpose of this study is to promote healthy dietary and physical activity (PA) behaviors in adolescents using a six-module nutrition education resource—Wise Eating (WE)—which was designed specifically for the adolescent population based on the concept and principles of Intuitive Eating (IE).  Study Design: Repeated measures study with pre-assessment and post-assessment. Outcome Measures and Analysis: This study assessed participating adolescents’ breakfast intake, fruit and vegetable (FV) consumption, and PA behaviors; perceptions of IE factors; and perceptions of the Theory of Planned Behavior (TPB) variables. Independent samples t-tests and one-way ANOVAs were used to determine differences in demographic variables and differences between the control and the intervention group. Paired t-tests were performed to compare the behavioral and perception changes from the pre-assessment to the post-assessment. Multiple linear regressions were performed to examine the relationship between TPB variables and FV consumption and PA participation intent and behaviors. Results: The total number of participants at the pre- and the post-assessment was 154 and 148, respectively. Participant’s gender and grade level were evenly distributed. Hispanic was identified as the predominant ethnic population at both the pre- and the post-assessment. At post-assessment, participants in the intervention group significantly increased their breakfast intake frequency, FV consumption frequency, and PA participation frequency (P < .05). Sixth graders had significantly higher breakfast intake frequency, FV consumption frequency, and PA participation frequency when compared with 7th and 8th graders (P < .05). The TPB variables significantly predicted FV consumption and PA intent and behaviors at both the pre- and the post-assessment, and the perceived behavioral control served as the most consistent predictor. For the intervention group, the IE total and Factor 1—Unconditional Permission to Eat scores were significantly increased at the post-assessment when compared with the control group (P .001). Conclusions: These findings tested the effectiveness of WE education modules and further emphasized the need for more interventions on IE to improve dietary and PA behaviors change in the adolescent population.

Magister Scientiae - MSc / Since Helichrysum is known by the indigenous people of Africa for therapeutic properties, such as against colds, flu and wounds, the aim of this study was to focus on the patulum species found predominantly in the Western Cape region of South Africa and by means of isolation and identification of the plant constituents, be able to relate the therapeutic activity on the basis of literature precedents, to the compounds extracted. / South Africa

The objective of the following study was threefold: to conduct a homoeopathic drug proving of Acacia xanthophloea 30CH on healthy individuals in order to elucidate the totality of signs and symptoms produced by the drug substance; to analyse the signs and symptoms gathered from the proving, collate the data, and convert the symptoms into materia medica symptoms and rubrics; to compare the symptoms of the proving to the doctrine of signatures. Methodology This proving study was a double-blinded, placebo controlled study. Thirty provers or participants were recruited for the study and the sample size was divided equally between two researchers (A. Gobind and G. Zondi). The sample was randomly divided into two groups, with one group receiving an active substance (verum group) and the other group receiving a placebo (control group). Amongst the 30 provers, 24 participants received verum and six received placebo. Each prover was given a journal to record their symptoms, a pen and nine powders. The duration of this proving study was six weeks including the first week of baseline during which time each prover was required to record their symptoms before taking the proving substance. This procedure was clearly explained to each prover and an information sheet with detail explanation of the proving procedure was provided and informed consent obtained. A thorough case history was taken in the initial consultation and physical examinations to ensure that individuals participating met the inclusion criteria and were healthy. Results Information derived both researchers was combined and the extraction of signs and symptoms then commenced. The symptoms were translated into materia medica and repertory format and graded accordingly. Thereafter the symptoms that emerged from the study were discussed and compared with the doctrine of signatures of Acacia xanthophloea. Provers experienced a wide range of symptoms mentally and emotionally e.g. anger, poor concentration and focus, disconnected feeling, depression, stress, anxiety, antisocial/ aversion to company, tranquillity. A large number of physical symptoms were noted by provers e. g. headaches, ailments of extremities (joint pain, weakness), female related symptoms (irregular menses, decrease/ increase libido etc.), eye symptoms, skin symptoms and general symptoms. The comparison of the symptoms of Acacia xanthophloea 30CH to the doctrine of signatures of the tree Acacia xanthophloea illustrated certain similarities, especially with regard to skin symptoms, eye symptoms, gastrointestinal symptoms and headaches. Conclusion The proving substance Acacia xanthophloea 30CH did produced signs and symptoms when given to healthy individuals as hypothesised. The symptoms when compared to the doctrine of signatures of the acacia xanthophloea tree did show correlation as hypothesised. / M

M.Sc. / The continued use and popularity of plant based traditional medicine necessitates scientific validation of the therapeutic potential of medicinal plants through phytochemical and pharmacological screening as well as the isolation and identification of bioactive compounds. Since the pharmacological effectiveness of medicinal plants is affected by several intrinsic and extrinsic factors, studies on the variations on chemical composition and biological activity are important as well. These provide a scientific rationale for using plants from different regions for the same medicinal purposes and allow traditional healers and consumers to make informed decisions with regard to the collection and use. Rapanea melanophloeos is a popular medicinal plant from the Myrsinaceae family widely distributed in southern Africa. It‟s bark, fruits and rarely the leaves are used traditionally for ailments ranging from stomach disorders, respiratory problems to disorders of the nervous system. Available chemical information reports on the accumulation of benzoquinones as major compounds, as well as some triterpenoid saponins and tannins. In view of the plant‟s wide distribution and medicinal use of different plant parts, this study comparatively evaluated the chemical composition of various crude extracts of the leaves, fruits and bark of plants collected from six localities. This was coupled with antibacterial tests to evaluate the therapeutic potential of different solvent extracts of the leaves, fruits and bark as well as the isolation of bioactive compounds from the fruits. Plants were collected from six different localities between Swaziland and South Africa and sequentially extracted with petroleum ether, ethyl acetate, methanol and water as a series of increasingly polar solvents. Thin layer chromatography (TLC), Gas-Chromatography/Mass spectrometry (GC-MS) and High Performance Liquid Chromatography (HPLC) were used to obtain a semi-quantitative chemical composition profile of different extracts. The TLC fingerprints of petroleum ether, ethyl acetate and methanol extracts showed the accumulation of non-polar terpenes, benzoquinones, saponins, tannins and flavonoids in the three plant parts. Slight variations in the chemical composition of the leaves, bark, and fruits were noted. Some components occurred in specific plant parts and others occurred in all three plants. The chemical profile of the leaves and bark were quite comparable in most instances with the fruits showing a generally different profile. This confirms previous literature reports on the comparability of leaves and the bark accounting for interchangeable use in traditional medicine.