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NOBRE, Karine Arnaud. Avaliação de Galactomanana da Adenanthera pavonina na Formação de Sistemas Matriciais. 2012. 73 f. Dissertação (Mestrado em química)-Universidade Federal do Ceará, Fortaleza-CE, 2012. / Submitted by Elineudson Ribeiro (elineudsonr@gmail.com) on 2016-06-02T18:37:12Z No. of bitstreams: 1 2012_dis_kanobre.pdf: 2192698 bytes, checksum: d377ad8a1fa2cced0f69e97fa78b2f58 (MD5) / Approved for entry into archive by José Jairo Viana de Sousa (jairo@ufc.br) on 2016-07-14T23:20:24Z (GMT) No. of bitstreams: 1 2012_dis_kanobre.pdf: 2192698 bytes, checksum: d377ad8a1fa2cced0f69e97fa78b2f58 (MD5) / Made available in DSpace on 2016-07-14T23:20:24Z (GMT). No. of bitstreams: 1 2012_dis_kanobre.pdf: 2192698 bytes, checksum: d377ad8a1fa2cced0f69e97fa78b2f58 (MD5) Previous issue date: 2012 / The improvement in the development of modified release matrix systems strictly depends on the selection of an appropriate agent capable of controlling drug release, support the therapeutic action over time and / or releasing the drug at a particular tissue or organ damage. Among the various options, the polymers are versatile and promising agents to perform such function. In this study, galactomannan Adenanthera pavonina was investigated as a potential basis for the development of a system for controlled release hydrophilic matrix. To obtain a slow and prolonged release of rutin and mangiferin, hydrophilic matrices were prepared using different concentrations of polymer and different methods of preparation: the physical mixture and spray drier. The controlled release matrix containing rutin and natural gum (galactomannan) was compared with the most commercially used (containing hydroxypropyl methylcellulose [HPMC] as a control agent), as determining the most efficient method of preparation was done by comparing the matrices containing mangiferin. The rate of drug release in vitro as well as the release mechanism and the release kinetics were determined by zero- order, Higuchi and Korsmeyer equations. The analysis revealed a release of the drug release mechanism similar to the matrices developed. Systems containing galactomannan had a better control of drug release as compared with systems containing HPMC. Among the methods used in this work, the spray drier method is more efficient for the controlled release showing a slower release and continuous. New formulations for drug delivery from matrix systems were proposed. / A melhoria no desenvolvimento de sistemas matriciais de liberação modificada depende estritamente da seleção de um agente apropriado capaz de controlar a liberação do fármaco, sustentar a ação terapêutica ao longo do tempo e/ou de liberar o fármaco ao nível de um determinado tecido ou órgão alvo. Dentre as várias opções, os polímeros são agentes versáteis e promissores para exercer tal função. Neste estudo, a galactomanana da Adenanthera pavonina foi investigada como base potencial para o desenvolvimento de um sistema de matriz hidrofílica de liberação controlada. Para se obter uma liberação prolongada e lenta de rutina e mangiferina, matrizes hidrofílicos foram preparados utilizando concentrações diferentes de polímero e métodos distintos de preparo: mistura física e por spray drier. A matriz de liberação controlada contendo rutina e goma natural (galactomanana) foi comparada com matrizes comercialmente mais utilizadas (contendo hidroxipropil metilcelulose [HPMC] como agente controlador), já a determinação do método de preparo mais eficiente foi feita comparando as matrizes contendo mangiferina. A taxa de libertação invitro de drogas, bem como o mecanismo de liberação e a cinética de liberação foram determinados por meio de ordem zero, Higuchi e as equações Korsmeyer. A análise de liberação da droga revelou um mecanismo de liberação semelhante para as matrizes desenvolvidas. Os sistemas contendo galactomanana apresentaram um melhor controle na liberação do fármaco quando comparado com os sistemas contendo HPMC. Dentre os métodos de preparação utilizados o método de spray drier se mostrou mais eficiente para liberação controlada apresentando uma liberação mais lenta e contínua. Novas formulações para a liberação controlada de fármacos a partir de sistemas matricial foi proposto.

FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / A melhoria no desenvolvimento de sistemas matriciais de liberaÃÃo modificada depende estritamente da seleÃÃo de um agente apropriado capaz de controlar a liberaÃÃo do fÃrmaco, sustentar a aÃÃo terapÃutica ao longo do tempo e/ou de liberar o fÃrmaco ao nÃvel de um determinado tecido ou ÃrgÃo alvo. Dentre as vÃrias opÃÃes, os polÃmeros sÃo agentes versÃteis e promissores para exercer tal funÃÃo. Neste estudo, a galactomanana da Adenanthera pavonina foi investigada como base potencial para o desenvolvimento de um sistema de matriz hidrofÃlica de liberaÃÃo controlada. Para se obter uma liberaÃÃo prolongada e lenta de rutina e mangiferina, matrizes hidrofÃlicos foram preparados utilizando concentraÃÃes diferentes de polÃmero e mÃtodos distintos de preparo: mistura fÃsica e por spray drier. A matriz de liberaÃÃo controlada contendo rutina e goma natural (galactomanana) foi comparada com matrizes comercialmente mais utilizadas (contendo hidroxipropil metilcelulose [HPMC] como agente controlador), jà a determinaÃÃo do mÃtodo de preparo mais eficiente foi feita comparando as matrizes contendo mangiferina. A taxa de libertaÃÃo invitro de drogas, bem como o mecanismo de liberaÃÃo e a cinÃtica de liberaÃÃo foram determinados por meio de ordem zero, Higuchi e as equaÃÃes Korsmeyer. A anÃlise de liberaÃÃo da droga revelou um mecanismo de liberaÃÃo semelhante para as matrizes desenvolvidas. Os sistemas contendo galactomanana apresentaram um melhor controle na liberaÃÃo do fÃrmaco quando comparado com os sistemas contendo HPMC. Dentre os mÃtodos de preparaÃÃo utilizados o mÃtodo de spray drier se mostrou mais eficiente para liberaÃÃo controlada apresentando uma liberaÃÃo mais lenta e contÃnua. Novas formulaÃÃes para a liberaÃÃo controlada de fÃrmacos a partir de sistemas matricial foi proposto. / The improvement in the development of modified release matrix systems strictly depends on the selection of an appropriate agent capable of controlling drug release, support the therapeutic action over time and / or releasing the drug at a particular tissue or organ damage. Among the various options, the polymers are versatile and promising agents to perform such function. In this study, galactomannan Adenanthera pavonina was investigated as a potential basis for the development of a system for controlled release hydrophilic matrix. To obtain a slow and prolonged release of rutin and mangiferin, hydrophilic matrices were prepared using different concentrations of polymer and different methods of preparation: the physical mixture and spray drier. The controlled release matrix containing rutin and natural gum (galactomannan) was compared with the most commercially used (containing hydroxypropyl methylcellulose [HPMC] as a control agent), as determining the most efficient method of preparation was done by comparing the matrices containing mangiferin. The rate of drug release in vitro as well as the release mechanism and the release kinetics were determined by zero- order, Higuchi and Korsmeyer equations. The analysis revealed a release of the drug release mechanism similar to the matrices developed. Systems containing galactomannan had a better control of drug release as compared with systems containing HPMC. Among the methods used in this work, the spray drier method is more efficient for the controlled release showing a slower release and continuous. New formulations for drug delivery from matrix systems were proposed.

Hybrid composites forms an important field of research in the area of composite science and engineering as it gives the advantage of avoiding complex lay-up designs and provides better tuning compatibility to get desired properties in comparison with their mono-fiber counterpart. Further, utilization of composites for low temperature structures has been hindered by inconsistency of material property data and not much is reported on thermal characteristics of hybrid composites at cryogenic temperatures. This research work is focused on development of carbon-glass epoxy hybrid composite and to study the thermal behavior of these materials in comparison to its mono-fiber counterparts especially at cryogenic temperatures. The objectives are classified into the following three parts: Development of a hybrid composite with urethane modified epoxy matrix system (toughening agent used is Propyltrimethoxysilane (PTMO) and Toluene Di-Isocyanate (TDI) is added to get the polyurethane structure), for cryogenic applications. Study and understand the limitations and complexities of the experimental methodologies involved in evaluating the thermal properties of these materials namely thermal conductivity, coefficient of thermal expansion and specific heat. Finally to look into the appropriate theoretical calculations and experimental results to understand the variations, if any, for these materials. Specifically the following contributions are reported in this thesis: Evaluated the modified matrix system for its physical and mechanical properties at 20K. Specimens were prepared with D638 ASTM standard, modified to suit pin loading configuration in the cryostat/Instron machine. After assessing the suitability of the matrix system, mono fibre composites of different types were made and evaluated their thermal properties viz, coefficient of thermal expansion, thermal conductivity and specific heat down to 20K. Based on the results of the above, a hybrid composite configuration was evolved which exhibits optimal thermal characteristics at low temperatures and its characterization for various thermal properties at cryogenic temperatures was carried out. Comparisons of the experimental results were made with macro-mechanical model and micro-mechanical model (rule of mixtures) of composite materials. The present work throws light to the fact that hybrid polymer matrix composites can very well be considered for cryogenic applications where the combination or trade off between properties like strength to conductivity ratio, modulus to conductivity ratio and low cost is to be made. The mechanical properties of hybrid composites also need to be studied to complement the study on thermal properties reported in this thesis. It is essential to have a complete understanding of behaviour of these materials at cryogenic temperatures with respect to both thermal and mechanical properties as it is evident from the available literature that the emerging demands are multi-disciplinary in nature. The present research work is aimed at highlighting the use of hybrid composites to achieve the desirable thermal properties and thereby inviting the attention of scientists and engineers who are engaged in the design of cost effective structures and appliances for cryogenic environments to focus on further research to develop

This thesis aims to investigate the controllability and observability of the discrete fractional linear time-invariant state-space model. First, we will establish key concepts and properties which are the tools necessary for our task. In the third chapter, we will discuss the discrete state-space model and set up the criteria for these two properties. Then, in the fourth chapter, we will attempt to apply these criteria to the discrete fractional model. The general flow of our objectives is as follows: we start with the first-order linear difference equation, move on to the discrete system, then the fractional difference equation, and finally the discrete fractional system. Throughout this process, we will develop the solutions to the (fractional) difference equations, which are the basis of our criteria.

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