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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.
1

Les hydrocarbures aromatiques polycycliques dans le café : mise au point de méthodes analytiques et étude de l'étape de torréfaction

Houessou, Justin Koffi 01 February 2007 (has links) (PDF)
No description available.
2

Model Predictive Control (mpc) Performance For Controlling Reaction Systems

Asar, Isik 01 June 2004 (has links) (PDF)
In this study, the performance of the Model Predictive Controller (MPC) algorithm is investigated in two different reaction systems. The first case is a saponification reaction system where ethyl acetate reacts with sodium hydroxide to produce sodium acetate and ethanol in a CSTR. In the reactor, temperature and sodium acetate concentration are controlled by manipulating the flow rates of ethyl acetate and cooling water. The model of the reactor is developed considering first principal models. The experiments are done to obtain steady state data from the reaction system and these are compared with the model outputs to find the unknown parameters of the model. Then, the developed model is used for designing SISO and MIMO-MPC considering Singular Value Decomposition (SVD) technique for coupling. The second case is the reaction system used for the production of boric acid by the reaction of colemanite and sulfuric acid in four CSTR&rsquo / s connected in series. In the reactor, the boric acid concentration in the fourth reactor is controlled by manipulating the sulfuric acid flow rate fed to the reactor. The transfer functions of the process and disturbance (colemanite flow rate) are obtained experimentally by giving step changes to the manipulated variable and to the disturbance. A model-based and constrained SISO-MPC is designed utilizing linear step response coefficients. The designed controllers are tested for performance in set point tracking, disturbance rejection and robustness issues for the two case studies. It is found that, they are satisfactory except in robustness issues for disturbance rejection in boric acid system.
3

Síntese e caracterização de partículas de poli(álcool vinílico) utilizadas em aplicações biomédicas: contribuição da análise fractal e entropia de Shannon

Silva, Danilo Antonio da [UNESP] 10 February 2011 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:22:55Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-02-10Bitstream added on 2014-06-13T20:10:06Z : No. of bitstreams: 1 silva_da_me_sjrp.pdf: 1617803 bytes, checksum: ac272edc3fa2d00a58fa6e743064acda (MD5) / Embolização e quimioembolização são exemplos de procedimentos minimamente invasivos aplicados em medicina com objetivo de evitar e/ou amenizar efeitos colaterais causados por tratamentos e intervenções cirúrgicas convencionais. Partículas de poli(álcool vinílico) (PVA) destacam-se entre os materiais utilizados nesses procedimentos por apresentarem características físico-químicas desejáveis como elevada compressibilidade, biocompatibilidade e biodegradabilidade. A proposta deste trabalho foi sintetizar e caracterizar microesferas de PVA/PVAc com tamanhos de partículas entre 30µm e 1200µm por reação de polimerização em suspensão seguida por uma etapa de saponificação. Além disso, estudar a influência da concentração de solução alcalina no processo de saponificação. A caracterização morfológica e estrutural foi feita com auxílio das técnicas de microscopia eletrônica de varredura (MEV) e difração de raios-X (DRX). Além da caracterização físico-química, foi realizado o estudo histopatológico mediante implante subcutâneo das partículas em ratos, análise de dimensão fractal e entropia de Shannon. Os resultados mostraram que a concentração de solução alcalina exerce forte influência na cristalinidade, coloração e características superficiais do polímero obtido. As partículas com alta cristalinidade (saponificadas com solução 25 mol/L de NaOH) induziram à reação inflamatória similar ao comportamento observado para partículas disponíveis comercialmente, enquanto que as partículas menos cristalinas (saponificadas com solução 4 mol/L de NaOH) resultaram em baixa intensidade de reação inflamatória no tecido celular subcutâneo dos ratos. Dimensão fractal... / Embolization and chemoembolization are examples of minimally invasive procedures applied in medicine in order to avoid and/or reduce side effects caused by conventional treatments and surgeries. Particles of poly(vinyl alcohol) (PVA) stand out among these materials due to desirable physical and chemical characteristics such as high compressibility, biocompatibility and biodegradability. The purpose of this study was to synthesize and characterize PVA/PVAc microspheres with sizes between 30µm and 1200µm by reaction of suspension polymerization step followed by a process of saponification. Moreover, study the influence of the concentration of alkaline solution in the process of saponification. The morphological and structural characterization was made with scanning electron microscopy (SEM) and X-ray diffraction (XRD). In addition to the physico-chemical characterization, it was carried the histopathological study by subcutaneous implantation of particles in rats, analysis of fractal dimension and Shannon´s entropy. The results indicated that the concentration of alkaline solution strongly influence the crystallinity, color and surface characteristics of the polymer. Highly crystalline particles (saponified with 25 mol/L NaOH) induced inflammatory reaction similar to the behavior observed for the commercial particles, while particles with lower crystallinity (saponified with 4 mol/L NaOH) presented lower inflammation in the subcutaneous tissue of rats. Fractal dimension and Shannon´s entropy showed satisfactory correlation with the histopathological analysis: the values have changed as the permanence time of particles in rats, behavior was satisfactory from a clinical standpoint because it corroborates the qualitative changes observed in the subcutaneous tissues in response to disturbance of the immune... (Complete abstract click electronic access below)
4

Síntese e caracterização de partículas de poli(álcool vinílico) utilizadas em aplicações biomédicas : contribuição da análise fractal e entropia de Shannon /

Silva, Danilo Antonio da. January 2011 (has links)
Resumo: Embolização e quimioembolização são exemplos de procedimentos minimamente invasivos aplicados em medicina com objetivo de evitar e/ou amenizar efeitos colaterais causados por tratamentos e intervenções cirúrgicas convencionais. Partículas de poli(álcool vinílico) (PVA) destacam-se entre os materiais utilizados nesses procedimentos por apresentarem características físico-químicas desejáveis como elevada compressibilidade, biocompatibilidade e biodegradabilidade. A proposta deste trabalho foi sintetizar e caracterizar microesferas de PVA/PVAc com tamanhos de partículas entre 30µm e 1200µm por reação de polimerização em suspensão seguida por uma etapa de saponificação. Além disso, estudar a influência da concentração de solução alcalina no processo de saponificação. A caracterização morfológica e estrutural foi feita com auxílio das técnicas de microscopia eletrônica de varredura (MEV) e difração de raios-X (DRX). Além da caracterização físico-química, foi realizado o estudo histopatológico mediante implante subcutâneo das partículas em ratos, análise de dimensão fractal e entropia de Shannon. Os resultados mostraram que a concentração de solução alcalina exerce forte influência na cristalinidade, coloração e características superficiais do polímero obtido. As partículas com alta cristalinidade (saponificadas com solução 25 mol/L de NaOH) induziram à reação inflamatória similar ao comportamento observado para partículas disponíveis comercialmente, enquanto que as partículas menos cristalinas (saponificadas com solução 4 mol/L de NaOH) resultaram em baixa intensidade de reação inflamatória no tecido celular subcutâneo dos ratos. Dimensão fractal... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Embolization and chemoembolization are examples of minimally invasive procedures applied in medicine in order to avoid and/or reduce side effects caused by conventional treatments and surgeries. Particles of poly(vinyl alcohol) (PVA) stand out among these materials due to desirable physical and chemical characteristics such as high compressibility, biocompatibility and biodegradability. The purpose of this study was to synthesize and characterize PVA/PVAc microspheres with sizes between 30µm and 1200µm by reaction of suspension polymerization step followed by a process of saponification. Moreover, study the influence of the concentration of alkaline solution in the process of saponification. The morphological and structural characterization was made with scanning electron microscopy (SEM) and X-ray diffraction (XRD). In addition to the physico-chemical characterization, it was carried the histopathological study by subcutaneous implantation of particles in rats, analysis of fractal dimension and Shannon's entropy. The results indicated that the concentration of alkaline solution strongly influence the crystallinity, color and surface characteristics of the polymer. Highly crystalline particles (saponified with 25 mol/L NaOH) induced inflammatory reaction similar to the behavior observed for the commercial particles, while particles with lower crystallinity (saponified with 4 mol/L NaOH) presented lower inflammation in the subcutaneous tissue of rats. Fractal dimension and Shannon's entropy showed satisfactory correlation with the histopathological analysis: the values have changed as the permanence time of particles in rats, behavior was satisfactory from a clinical standpoint because it corroborates the qualitative changes observed in the subcutaneous tissues in response to disturbance of the immune... (Complete abstract click electronic access below) / Orientador: Prof. Dr. José Geraldo Nery / Coorientador: Dra. Rosa Sayoko Kawasaki-Oyama / Banca: José Geraldo Nery / Banca: Moacir Fernandes de Godoy / Banca: Sebastião Roberto Taboga / Mestre
5

ProduÃÃo de Ãcidos Graxos Assistida por Ultrassom Visando à ProduÃÃo de Biodiesel / Production of Fatty Acids Carried out by Ultrasound Aiming the Production of Biodiesel

Larissa Pinto de Lima 25 February 2010 (has links)
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / A produÃÃo de biodiesel por reaÃÃo de transesterificaÃÃo à realizada geralmente usando Ãleos com baixo Ãndice de acidez, restringindo o mÃtodo ao uso de uma pequena variedade de Ãleos vegetais. MatÃrias primas com elevado Ãndice de acidez podem ser utilizadas como rota alternativa para a produÃÃo de biodiesel. O objetivo desta dissertaÃÃo foi produzir Ãcidos graxos a partir de Ãleos residuais (com percentual de Ãcidos graxos superior a 1%) por saponificaÃÃo assistida por ultrassom, seguida por hidrÃlise Ãcida. A aplicaÃÃo de ondas ultrassÃnicas teve o intuito de acelerar o processo de produÃÃo de Ãcidos graxos, diminuindo o tempo da reaÃÃo de saponificaÃÃo. Os Ãcidos graxos foram produzidos a partir do Ãleo de fritura de palma e do Ãleo de peixe por reaÃÃo de saponificaÃÃo assistida por ultrassom seguida de hidrÃlise Ãcida. Um planejamento experimental foi realizado para avaliar as condiÃÃes operacionais razÃo molar Ãlcool:Ãleo, concentraÃÃo de KOH e temperatura para o Ãleo de fritura e razÃo molar Ãlcool:Ãleo, concentraÃÃo de KOH para o Ãleo de peixe, uma vez que a temperatura nÃo mostrou ser uma variÃvel estatisticamente significativa. Para as reaÃÃes com o Ãleo de fritura, a maior conversÃo obtida foi de 97,3% a uma temperatura de 60ÂC, com razÃo molar 3:1 e concentraÃÃo de KOH de 0,3%. Para as reaÃÃes com o Ãleo de peixe, empregando as mesmas condiÃÃes reacionais para o Ãlcool e para o KOH, apenas 78,5% de conversÃo em Ãcidos graxos foi alcanÃado. Essa conversÃo um pouco menor para o Ãleo de peixe, quando comparada com o Ãleo de fritura, està relacionada com sua alta viscosidade, que acaba por impedir uma melhor miscibilidade entre os reagentes. Um estudo comparativo entre as reaÃÃes de saponificaÃÃo do Ãleo de fritura foi realizado usando o mÃtodo convencional de refluxo e o assistido por ultrassom. O resultado apresentou uma diferenÃa satisfatÃria para a reaÃÃo assistida por ultrassom, com uma diferenÃa de 39,2% de conversÃo nos cinco primeiros minutos de reaÃÃo quando comparada com a reaÃÃo submetida ao refluxo. Depois de produzidos, os Ãcidos graxos foram esterificados com Ãlcool metÃlico na presenÃa de Ãcido sulfÃrico como catalisador. No planejamento experimental realizado para as reaÃÃes de esterificaÃÃo dos Ãcidos graxos, as variÃveis razÃo molar Ãlcool:Ãcido e concentraÃÃo de catalisador foram significativas estatisticamente. AtravÃs dos experimentos, as curvas cinÃticas foram construÃdas. A produÃÃo de biodiesel a partir de Ãcidos graxos de fritura assistida por ultrassom obteve conversÃes superiores a 96% (especificaÃÃo exigida pela ANP). Ao aplicar a metodologia descrita no respectivo trabalho (aplicaÃÃo do ultrassom na reaÃÃo de saponificaÃÃo), uma alta conversÃo de Ãcidos graxos à alcanÃada em tempos reacionais reduzidos, mostrando ser uma Ãtima matÃria prima para a produÃÃo de biodiesel. / The production of biodiesel by means of transesterification reaction is usually carried out using oils with low acid index. As such, the direct use of this method is restricted to a small number of oils. But raw materials with high acid index still can be used for biodiesel production. The objective of this study is to produce biodiesel from waste oils, with more than 1% of free fatty acids, by means of saponification followed by acid hydrolysis and esterification. The process will be carried out by ultrasound technology. The use of ultrasound aimed increasing the reaction rate and to diminish the total time of reaction. The free fatty acids were produced from waste palm oil and fish oil (Nile tilapia oil). An experimental planning based on response surface methodology was carried out to evaluate the main operating conditions: alcohol to oil molar ratio, KOH concentration and temperature. The highest yield of free fatty acids from waste palm oil, 97.3%, was obtained operating at 60oC, alcohol to oil molar ratio of 3 and 0.3% KOH. The highest yield of free fatty acids from fish oil, 78.5%, was obtained operating at 30oC, alcohol to oil molar ratio of 3 and 0.3% KOH. The lower yield observed for fish oil was related to the higher viscosity of the oil during processing, which prevents good miscibility between the components. A comparative study between the conventional method and the ultrasound technology on the production of biodiesel from waste palm oil showed that the application of ultrasound increased by 39.2% the conversion of oil into free fatty acids during the first 5 min of reaction. The free fatty acids were esterified with methanol using sulfuric acid as catalyst. An experimental planning based on response surface methodology was carried out to evaluate the main operating conditions of the esterification of the free fatty acids: alcohol to free fatty acids molar ratio and catalyst concentration. A dynamic study was also carried out for the production of biodiesel from free fatty acids. The yield of biodiesel from palm free fatty acids was higher than 96%, lower limit specified by ANP for the commercialization of biodiesel. The methodology developed in this study showed that high yield of free fatty acids was obtained at short reaction times being a good methodology to produce biodiesel.
6

Desenvolvimento de um processo para a obtenção de policosanol a partir de cera de cana-de-açucar (Saccharum officinarum) / Development of a process for obtaining policosanol from sugarcane wax (Saccharum officinarum)

Rozario, Claudia Helena Ribeiro do 22 February 2003 (has links)
Orientador: Daniel Barrera Arellano / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-05T16:00:17Z (GMT). No. of bitstreams: 1 Rozario_ClaudiaHelenaRibeirodo_M.pdf: 746633 bytes, checksum: 09b06bd81821694a0159e905ae2e7722 (MD5) Previous issue date: 2006 / Resumo: A cera de cana-de-açúcar (Saccharum officinarum), extraída da torta de filtração, um subproduto da indústria sucro-alcooleira, tem sido uma matéria de interesse não somente pela sua aplicação industrial como alternativa para as ceras de carnaúba, abelha e sintéticas, mas também pela sua composição química. A cera de cana-deaçúcar é uma fonte natural de álcoois alifáticos primários de cadeia longa, com 24 a 34 átomos de carbono, com predominância do octacosanol. Essa mistura de álcoois de alto peso molecular, denominada ¿policosanol¿, tem chamado a atenção pelas suas propriedades farmacológicas, sendo comercializada industrialmente como componente ativo em diversas formulações com efeitos anti-plaquetários, anti-trombóticos e redutores de colesterol. Neste trabalho, foram estudadas as etapas envolvidas no processo de obtenção de uma mistura de álcoois a partir de cera de cana-de-açúcar, compostas de (1) purificação da cera bruta de cana-de-açúcar pelo método do álcool a quente; (2) saponificação da cera purificada com NaOH, na presença de etanol como solvente; (3) separação da mistura de álcoois da cera saponificada, utilizando solução salina e etanol, para obtenção do produto denominado ¿policosanol 50¿ e, (4) purificação com acetona do produto obtido em (3), para obtenção do produto denominado ¿policosanol 90¿. Como a reação de saponificação pode interferir no rendimento do composto de interesse, foram aplicadas técnicas de planejamento experimental nesta etapa e, de acordo com os resultados obtidos, novos testes foram realizados para se determinar as condições mais favoráveis para a reação. A proporção cera:solução de NaOH foi mantida em 1:1 (p:v) e, com este parâmetro fixado, as condições determinadas para a reação de saponificação foram: concentração da solução alcoólica de NaOH de 2M, temperatura de 80ºC e tempo de 15 minutos. Nestas condições, o produto denominado ¿policosanol 50¿ apresentou um rendimento de 55% e uma pureza em álcoois de 50% e o produto denominado ¿policosanol 90¿ apresentou um rendimento de 25,7% e uma pureza em álcoois de 92,3% / Abstract: Sugarcane wax (Saccharum officinarum), extracted from filter cake, a by-product of the sugar and alcohol industry, has been a material of interest, not only for its industrial application, as an alternative to ¿carnaúba¿ wax, bees wax and synthetic waxes, but also for its chemical composition. Sugarcane wax is a natural source of long-chain primary aliphatic alcohols, with 24 to 34 carbon atoms, with a predominance of octacosanol. This mixture of high molecular weight alcohols called policosanol, has been investigated due to its pharmacological properties, being industrially commercialized as an active component in various formulations, with anti-platelet, anti-trombotic and cholesterolreducing effects. In this work, the stages involved in the process of obtaining a mixture of alcohols from sugarcane wax, composed of (1) purification of the raw sugarcane wax by the hot alcohol method; (2) saponification of the purified wax with NaOH in the presence of ethanol as solvent; (3) separation of the mixture of alcohols in the saponified wax using a salt solution and ethanol to obtain the product called ¿policosanol 50¿; and, (4) purification with acetone of the product obtained in (3), to obtain the product called ¿policosanol 90¿, were studied. As the saponification reaction can interfere in the yield of the composite of interest, experimental planning techniques were applied in this stage and, in accordance with the results obtained, new tests were conducted to determine the most favorable reaction conditions. The proportion wax:NaOH solution was maintained at 1:1 (w:v) and, with this parameter fixed, the conditions for the saponification reaction were: concentration of the NaOH alcoholic solution of 2M, temperature of 80ºC and time of 15 minutes. Under these conditions, the product denominated ¿policosanol 50¿ presented a yield of 55% and a purity in alcohols of 50%, and the product called ¿policosanol 90¿ presented a yield of 25.7% and a purity in alcohols of 92.3% / Mestrado / Mestre em Tecnologia de Alimentos
7

Análise técnica do potencial do óleo de Pinhão manso (Jatropha Curcas L.) como coletor na flotação de minerais / Technical analysis of potential of Pinhão manso oil (Jatropha curcas L.) as a collector in the floating of minerals

Moraes, Izabela Letícia Almeida de 01 June 2017 (has links)
Submitted by Franciele Moreira (francielemoreyra@gmail.com) on 2017-12-14T17:27:41Z No. of bitstreams: 2 Dissertação - Izabela Letícia Almeida de Moraes - 2017.pdf: 2791313 bytes, checksum: 95bb215d71f301f1f487b1e919c6304c (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-12-18T13:41:37Z (GMT) No. of bitstreams: 2 Dissertação - Izabela Letícia Almeida de Moraes - 2017.pdf: 2791313 bytes, checksum: 95bb215d71f301f1f487b1e919c6304c (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-12-18T13:41:37Z (GMT). No. of bitstreams: 2 Dissertação - Izabela Letícia Almeida de Moraes - 2017.pdf: 2791313 bytes, checksum: 95bb215d71f301f1f487b1e919c6304c (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-06-01 / Brazilian soils present acidity and in some parts are deficient in nutrients such as Nitrogen (N), Phosphorus (P) and Potassium (K). For the soil to be arable it is indispensable the artificial fertilization. Brazil is known worldwide for being a major producer of grains, according to the National Company of Supply (CONAB), assuming the position of the second largest soybean producer in the world in the harvest years 2015/2016. Apatite is the main natural source of phosphorus recognized as a raw material for the manufacture of fertilizers. The origin of the phosphate rock in Brazil is predominantly igneous, presenting a mineralogy containing silicate and carbonate mineral particles. Due to these gangue minerals present in the phosphate rock the flotation process becomes indispensable during the processing, to separate the apatite from the contaminants and to obtain the minimum level of impurities so that the fertilizers are produced to the required specifications. The difficult separation of the silica-carbonate ores from apatite occurs in the similarity of surface chemistry. The collecting reagent is used in the flotation process to aid in the separation of barley ores, in which the fatty acids, among them the saponified fatty acids, are those traditionally used, and the fatty acids obtained from vegetable or animal oil are matter Collector master prime. Jatropha curcas L., known as jatropha (Jatropha curcas L.), has been arousing national interest in recent years because it is a species with excellent oil quality. The cultivation of this oleaginous species occurs in several Brazilian regions, is a perennial plant and resistant to several variations of soil and climate. Jatropha stands out for the production capacity of its oil, which reaches 50% of its seeds, and for the lipid composition rich in fatty acids; Its major acids are linoleic, oleic, and palmitic. This study aims to evaluate the selectivity of the jatropha oil used as collector in the apatite, calcite and quartz flotation. And to be used as a collector the jatropha oil was characterized and tested in two methods of saponification, and the plant species was saponified at a temperature of approximately 90 oC so that in the other method the oil was saponified at room temperature. The mineral samples were chemically analyzed by X-ray fluorescence, scanning electron microscope (SEM) images, X-ray dispersive energy (EDS) spectrometry and potential zeta measurements. The test conditions were obtained using the concentrations of 1.0; 2.5; 5.0; 7.5; 10.0 mg / L in pH's 8, 9 and 10. In order to evaluate the performance of saponified jatropha oil, tests were carried out under the same conditions with the industrial collector FLOTIGAM 5806 from Clariant. The results show that cold saponified jatropha oil (PMSF) was better than hot saponified jatropha oil (PMSQ) and, when compared to the Flotigam, the results showed a similar performance. The PMSF and PMSQ collectors showed selectivity for apatite and calcite and for quartz collectors did not achieve significant recovery of the mineral. Thus, it can be concluded that jatropha oil as a collector has a potential for apatite flotation. / Os solos brasileiros apresentam acidez e em algumas partes são deficientes em nutrientes, como Nitrogênio (N), Fósforo (P) e Potássio (K). Para o solo se tornar mais fértil é indispensável a adubação artificial. O Brasil é mundialmente conhecido por ser um grande produtor de grãos, de acordo com a Companhia Nacional de Abastecimento (CONAB), assumindo o lugar de segundo maior produtor de soja do mundo na safra anos 2015/2016. A apatita é a principal fonte natural de fósforo reconhecido como matéria prima para a fabricação de fertilizantes. A origem da rocha fosfática no Brasil é predominantemente ígnea apresentando uma mineralogia contendo partículas minerais de silicato e carbonato. Devido a esses minerais de ganga presentes na rocha fosfática o processo de flotação se torna indispensável durante o beneficiamento, para separar a apatita dos contaminantes e obter o nível mínimo de impurezas para que os fertilizantes sejam produzidos seguindo as especificações exigidas. A difícil separação dos minérios sílico-carbonatado da apatita se dá à semelhança da química da superfície. O reagente coletor é usado no processo de flotação para auxiliar na separação dos minérios de ganga, em que os ácidos graxos, dentre eles os ácidos graxos saponificados, são os tradicionalmente utilizados, sendo que os ácidos graxos obtidos de óleo vegetal ou animal são a matéria prima principal do coletor. O pinhão manso, vem despertando interesse nacional nos últimos anos por ser uma espécie que apresenta um óleo de excelente qualidade. O cultivo dessa espécie oleaginosa ocorre em várias regiões brasileiras, é uma planta perene e resistente a diversas variações de solo e clima. O pinhão manso se destaca pela capacidade de produção do seu óleo, que chega a 50% de suas sementes, e pela composição lipídica rica em ácidos graxos; seus ácidos majoritários são linoleico, oleico e palmítico. Este estudo tem como objetivo avaliar a seletividade do óleo de pinhão manso utilizado como coletor na flotação apatita, calcita e quartzo. E para ser utilizado como coletor o óleo de pinhão manso foi caracterizado e testado em dois métodos de saponificação, sendo que a espécie vegetal foi saponificada em uma temperatura de aproximadamente 90 oC de modo que no outro método o óleo foi saponificado em temperatura ambiente. As amostras minerais foram analisadas quimicamente por fluorescência de raios-X (FRX), imagens de microscópio eletrônico de varredura (MEV), espectrometria de energia dispersiva de raios-X (EDS), difração de raios-X (DRX) e medidas potencial zeta (PZ). As condições dos testes foram obtidas utilizando as concentrações de 1,0; 2,5; 5,0; 7,5; 10,0 mg/L em pH’s 8, 9 e 10. Com o objetivo de avaliar a performance do óleo de pinhão manso saponificado foram realizados testes nas mesmas condições com o coletor industrial FLOTIGAM 5806 da empresa Clariant. Os resultados mostram que os coletores do óleo de pinhão manso saponificado a frio (PMSF) apresentaram melhor performance que o óleo de pinhão manso saponificado a quente (PMSQ) e, quando comparados com o Flotigam, os resultados mostraram uma performance semelhante. Os coletores PMSF e PMSQ mostraram que existe seletividade para a apatita e calcita e para o quartzo os coletores não alcançaram recuperação significativa do mineral. Desse modo, conclui-se que o óleo de pinhão manso como coletor apresenta um potencial para a flotação de apatita.
8

Preparations selectives de derives du 7-oxanorborna-2,5-diene : utilisation comme formes masquées de composés acetyleniques / Selective preparation of derivatives 7-oxanorborna-2,5-dienes : masked forms of acetylenic compounds

Sultan, Nisrine 09 September 2011 (has links)
En vue d’effectuer des préparations sélectives de composés hétérocycliques, une étude de la synthèse et de la réactivité de 7-oxanorborna-2,5-diènes portant des groupes électroattracteurs différents sur les positions 2 et 3 a été réalisée. Ces composés sont des formes masquées de composés acétyléniques dissymétriques.Dans un premier temps, nous avons optimisé une nouvelle méthode de synthèse sélective d’acétylènedicarboxylates dissymétriques par mono-transestérification d’acétylènedicarboxylates de dialkyle symétriques avec des alcools en présence de la lipase de Candida rugosa. Cette méthode nous a permis d’obtenir les diesters dissymétriques avec de bons rendements et une haute sélectivité a priori inattendue.Dans un second temps, nous avons développé des synthèses régiosélectives de dérivés de l’acide 7-oxanorborna-2,5-diène-2,3-dicarboxylique selon deux stratégies. Dans une première approche, une réaction de Diels-Alder intramoléculaire entre un furane et un composé acétylénique reliés par une agrafe siliciée a été réalisée, suivie d’une coupure des liaisons Si-C. Cette cycloaddition [4+2] s’effectue uniquement en présence de MeAlCl2 avec des rendements moyens. Dans certains cas, la coupure des liaisons Si-C conduit aux diesters désirés. Dans une deuxième approche, une mono-saponification d’oxanorbornadiène-2,3-dicarboxylates de dialkyle a permis d’accéder régiosélectivement à des monoacides et des réactions de couplage avec des amines ou des alcools ont conduit sélectivement à des dérivés présentant deux groupes électroattracteurs différents.Dans une dernière partie, nous avons effectué la préparation régiosélective de 3-pyrrolines par cycloaddition [2+3] d’un ylure d’azométhine suivie d’une réaction de rétro-Diels-Alder à partir des 7-oxanorbornadiènes comportant deux groupes électroattracteurs différents. La préparation aisée de 3-pyrrolines condensées non décrites dans la littérature a été obtenue par formation inattendue d’un motif succinimide dans le cas des amidoesters.En conclusion, il apparaît que la présence du groupe éthyle en tête de pont des 7-oxanorborna-2,5-diènes semble suffisante pour contrôler la régiosélectivité de ces cycloadditions. / In order to selectively prepare heterocyclic compounds, a study of the synthesis and reactivity of 7-oxanorborna-2,5-dienes with different electron-withdrawing groups on the 2 and 3 positions was performed. These compounds are masked forms of unsymmetrical acetylenic compounds. At first, we have optimized a new method for the selective synthesis of unsymmetrical diesters by transesterification of symmetrical dialkyl acetylenedicarboxylates in the presence of Candida rugosa lipase. This unexpectedly highly selective method allowed us to obtain unsymmetrical acetylenedicarboxylates in good yields.In a second part, we have developed a regioselective synthesis of 7-oxanorborna-2,5-diene-2,3-dicarboxylic acid derivatives according to two strategies. In one approach, an intramolecular Diels-Alder reaction between a furan and an acetylenic compound connected by silicon-containing tethers was performed, followed by a cleavage of the Si-C bonds. This [4+2] cycloaddition was carried in the presence of a Lewis acid, only MeAlCl2 gave the expected product and so in moderate yields. In most cases, the cleavage of Si-C bonds leads to the desired diesters. In a second approach, a mono-saponification of dialkyl oxanorbornadiene-2,3-dicarboxylates provided access regioselectively to mono-acids and coupling reactions with amines or alcohols selectively led to poly-functionalized products containing two different electron-withdrawing groups.In the last part, we have regioselectively prepared 3-pyrrolines by [2+3] cycloaddition of an azomethine ylide to 7-oxanorbornadienes bearing electroattracting groups followed by a retro-Diels-Alder reaction. An easy synthesis of previously unknown condensed 3-pyrrolines was obtained by formation of an unexpected succinimide pattern from amidoesters. In conclusion, it appears that the presence of an ethyl group on the bridgehead carbon atom of 7-oxanorborna-2,5-dienes seems sufficient to control the regioselectivity of these cycloadditions.
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Stanovení a vyhodnocení kosmetických mastí a návrh etikety dle aktuální legislativy / Determination and evaluation of cosmetic ointment and design of label according to actual legislation

Trávníčková, Eva January 2011 (has links)
This diploma thesis is focused on the study olephylic formulations – ointments and cream type of V/O. This thesis gives out information about production, use and properties 3 cosmetic ointments and about properties baby´s skin cream and the study of stability of these products in the presence of antioxidants - tocopherol acetate and rosemary extract. Ointments are made from hemp oil, olive oil and shea butter and chamomile extract. Each ointment is produced in two versions. Once the use of vitamin E as an antioxidant, a second is used as an antioxidant extract from rosemary. Among other important substances with positive effects on human skin include, for example, saturated fatty acids such as palmitic acid and stearic acid, unsaturated fatty acids such as oleic, linoleic, and more. Ointments are suitable for greasing dry to very dry skin hands, face and other body parts. The thesis also discusses the current legislation, which producer of cosmetics must comply, the details which must be placed on the label of a cosmetic product and it contains proposals of cosmetic labels Further thesis includes studying methods for determination of lipid characterizations were used for study of behaviour of ointments during time and during storage at different temperatures. They include iodine, acid, peroxide and saponification values. The ester value and the content of glycerol were counted.

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