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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.
51

Sistemas não invasivos para classificação de laranjas por meio de parâmetros físico-químicos / Non-invasive systems for oranges classification by means of physical and chemical parameters

Douglas William Menezes Flores 01 September 2015 (has links)
O controle de qualidade de laranjas desde a colheita até a comercialização é realizado com base em análises físico-químicas. Todavia, estas análises são destrutivas. Neste cenário, sistemas não invasivos para aferir a qualidade, são alternativas promissoras. O objetivo do trabalho foi avaliar os métodos de análises não destrutivas como a Ressonância Magnética em baixo campo (RMN) e espectroscopias de infravermelho médio (MIR) e próximo (NIR), associadas à quimiometria, para analisar parâmetros de qualidade de laranjas de forma não invasiva. O experimento ocorreu na unidade da Embrapa Instrumentação em São Carlos, SP. Foram coletadas 470 laranjas, obtidas em cultivos comerciais no interior do estado de São Paulo. As frutas passaram pelas etapas de seleção, higienização e sanitização. Em seguida, foram submetidas à análise não invasiva pelos equipamentos de RMN, NIR e MIR. Os parâmetros de qualidade avaliados foram, massa fresca, diâmetros longitudinal e transversal do fruto, teor de sólidos solúveis (SST), pH, acidez total titulável (ATT), índice de maturação (ratio) e rendimento de suco. Para os sinais de RMN foi aplicada a suavização de Savitzky-Golay com largura de janela de 21 pontos. Para os sinais de NIR foi aplicado a variação normal padrão (SNV) e para os sinais de MIR foi aplicada a normalização (0-1), seguido da segunda derivada. O modelo de predição foi construído utilizando a regressão por mínimos quadrados parciais (PLS) para cada parâmetro de qualidade. Os modelos desenvolvidos por RMN-PLS validados para predição foram: massa fresca; coeficiente de Pearson da predição (r) = 0,97, erro padrão da predição (SEP) = 13,57. Diâmetro longitudinal; r = 0,91 e SEP = 3,37. Diâmetro transversal; r = 0,92 e SEP = 2,73. SST; r = 0,81 e SEP = 0,88. Rendimento de suco; r = 0,78 e SEP = 3,26 e pH r = 0,74 e SEP = 0,17. Os parâmetros de índice de maturação e ATT não puderam ser validados utilizando RMN-PLS. Os modelos de NIR-PLS validados foram: SST; r = 0,92 e SEP = 0,71. ATT; r = 0,92 e SEP = 0,30. Os demais parâmetros não puderam ser validados por NIR-PLS. Para os modelos de MIR-PLS, o melhor resultado encontrado foi para validação interna do modelo de pH, r Validação = 0,80 e erro padrão da validação (SEV) de 0,16. A classificação desenvolvida utilizando os modelos de parâmetros físicos de RMN-PLS apresentaram acurácia para diâmetro transversal de 80,00%. As classificações por parâmetros químicos, como teor de sólidos solúveis revelou acurácia de 81,10% e para pH de 61,11%. Para as classificações por PLS-NIR para o ratio a acurácia foi igual a 87,95%. Os frutos classificados de forma não invasiva para a análise sensorial no teste de comparação pareada, apresentaram respostas significativas para sucos classificados pelos modelos de RMN-PLS a nível de p=0,05. Para os frutos classificados pelo NIR-PLS de forma não invasiva, a resposta ao segundo teste sensorial foi significativa a nível de p=0,05. Estes resultados comprovam a aplicabilidade destas técnicas como análises não invasivas para mensurar a qualidade de laranjas e classifica-las por parâmetros físico-químicos percebidos por provadores. / The quality control for oranges, after the harvest until commercialization are carried based on physical-chemical parameters. However, these analyzes are invasive. In this scenario, non-invasive systems to measure quality are promising options. Nuclear Magnetic Resonance (NMR) at low field and infrared spectroscopy (mid-infrared - MIR and near-infrared - NIR) were associated with chemometrics to analyze quality parameters in intact oranges. The experiment was carried at Embrapa São Carlos, SP. Four hundred and seventy oranges were obtained from commercial crops in the state of São Paulo. Samples were selected, cleaned and sanitized and then were submitted to non-invasive analysis by NMR, NIR and MIR equipment\'s. The evaluated reference quality parameters were fresh weight, longitudinal and transversal diameter, total soluble solids (TSS), pH, titratable acidity (TA), maturation index (ratio) and juice yield (%). For the non-invasive methods was applied pre-processing techniques on the signal. In NMR signal was applied Savitzky-Golay smoothing with 21 points width of window. For NIR signal was applied standard normal variant (SNV) and on the MIR signal normalization was applied (0-1), followed by the second derivative. The prediction model was constructed using partial least squares regression (PLS) for each quality reference parameter. The models developed by NMR-PLS validated by prediction were: fresh weight; Pearson coefficient prediction (r) = 0.97, standard error of prediction (SEP) = 13.57. Longitudinal diameter; r = 0.91 and SEP = 3.37. Transverse diameter; r = 0.92 and SEP = 2.73. SST; r = 0.81 and SEP = 0.88. Juice yield; r = 0.78 and SEP = 3.26. pH r = 0.74 and SEP = 0.17. The maturation index and titratable acidity parameters could not be validated using PLS-NMR. The validated NIR-PLS models were: SST; r = 0.92 and SEP = 0.71. ATT; r = 0.92 and SEP = 0.30. The others reference quality parameters were not validated by NIR-PLS. For models using MIR-PLS, the best result was found for internal validation of the pH model, r = 0.80 and standard validation error (SEV) 0.16. The classification models developed using NMR-PLS physical parameters showed accuracy in transverse diameter of 80.00%. The classifications by chemical parameters such as soluble solids revealed accuracy of 81.10% and 61.11% for pH. For classifications by PLS-NIR for the accuracy ratio was equal to 87.95%. Fruit classified noninvasively for sensory analysis in paired comparison test, showed significant responses to juices classified by NMR-PLS models at the level of p = 0.05. For fruit classified by NIR-PLS noninvasively, the answer to the second sensory test was significant at the level of p = 0.05. These results demonstrate the applicability of these techniques as non-invasive tests to measure the quality of oranges and sorts them by physicochemical parameters perceived by tasters.
52

A preliminary study on the effect of climatic conditions and fruit mineral concentration on the development of lenticel damage in 'Tommy Atkins' and 'Keitt' mangos (Mangifera indica L.) and rind pitting in 'Benny Valencia' oranges (Citrus sinensis).

Magwaza, Lembe Samukelo. January 2008 (has links)
The South African fresh fruit industry is a significant exporter, accounting for approximately 45% of the country’s agricultural exports. Of the total exported fruit in the 2005/06 season, 60% was subtropical fruit. However, certain physiological rind disorders such as mango lenticel damage and citrus rind pitting are frequently observed, reducing the commercial value of the fruit. This thesis deals with the epidemiology of these rind physiological disorders, in an attempt to obtain basic information that could serve as a guideline to predict and manage the fruit susceptibility to these disorders. The study further investigated the relative effects that certain pre-harvest factors have on the postharvest development of these disorders. Factors of particular interest were harvest maturity, climate and the mineral content of the fruit. Rind pitting is a physiological disorder of citrus that develops during storage. A study was conducted to investigate the relative effects that certain pre-harvest factors have on the post-harvest development of superficial rind pitting in ‘Benny Valencia’ oranges. Factors of particular interest were harvest maturity, climate and the mineral content of the fruit. In addition, trees were treated with two different formulations of nitrogen viz. limestone ammonium nitrate (LAN) and a slow release nitrogen fertilizer (Horticote®), during March 2006. The fruit were then sampled on a two-weekly basis over a period of three months. On each sampling date a set of quality related readings, such as juice sugar and titratable acid concentration were taken, after which the mineral concentration of the exocarp and mesocarp was measured. Fruit were also stored under export simulation conditions. The results indicate that fruit from trees that received additional N were more susceptible to rind pitting than those from control trees. Of the two N applications, fruit from trees that received slow release N were more susceptible to rind pitting than fruit from trees that received the LAN treatment. Another important observation made was that the nitrogen concentration of oranges from trees that received extra nitrogen fertilizer was lower than that from the controls. In addition, experimental fruit were smaller than control fruit. Fruit from trees that received the slow release nitrogen treatment were smallest. A sink/source hypothesis aimed at explaining this phenomenon has been formulated and is currently being investigated. A number of control mechanisms are also being explored. Mango lenticel damage is a serious defect that occurs on the rind of the fruit. This condition causes fruit to attain a speckled appearance and become unattractive to the buyer. Each season, the disorder reduces the packout of fresh fruit by about 16%. Several preharvest factors play a critical role in the postharvest development of lenticel damage. Preliminary studies have shown that the incidence of lenticel damage has some relationship to fruit moisture and fruit nutrient concentration, depending on which of these factors first achieve a critical threshold. A study was conducted to develop appropriate skin moisture content parameters to predict lenticel damage potential before harvest. The study further aimed to provide certain biological markers regarding appropriate nitrogen fertilization practices to reduce lenticel damage. To do this, two trials were conducted approximately a month before harvest. Firstly, a plastic ground cover to restrict water supply was laid under ‘Tommy Atkins’ trees at Numbi Estates in the Hazyview area of the Mpumalanga province, South Africa. Secondly, additional nitrogen was applied as three different formulations, viz. limestone ammonium nitrate (LAN), potassium nitrate (KNO3), and a slow release nitrogen fertilizer under trade name Horticote®, to two ‘Tommy Atkins’ and two ‘Keitt’ orchards at Bavaria Estates in the Hoedspruit area of the Limpopo province, South Africa. Fruit samples were harvested, packed and stored at different intervals after rain during January 2006. With regard to lenticel damage on ’Tommy Atkins’ fruit from Numbi, there was no significant difference between the control and plastic cover treatments. However, when compared to fruit from other localities, the Numbi fruit had the highest incidence of lenticel damage, followed by the conventional orchard at Bavaria. The Numbi fruit, which had the highest incidence of lenticel damage, also had the highest pulp and skin nitrogen concentration. Of the four treatments at Bavaria, the LAN treatment had the highest incidence of lenticel damage, but the pulp and skin nitrogen concentrations of this treatment were comparable with the other treatments. The organic fruit had significantly lower lenticel damage incidence and also had the lowest pulp and rind nitrogen concentrations. Similarly, ‘Keitt’ results showed that the intensity of lenticel damage was significantly higher in the orchard that received additional nitrogen in the form of LAN. From the results it was, however, not possible to formulate nitrogen-lenticel damage correlations. The study failed to prove the case for a direct relationship between the disorder and with nitrogen, as there were no significant or consistent correlations with nitrogen content. An interesting relationship was nevertheless observed between lenticel damage and the time of harvest before and after rainfall. The results indicated that both ‘Tommy Atkins’ and ‘Keitt’ fruit become more susceptible to lenticel damage when harvested a day after rainfall and this gradually reduces afterwards. The effect of rainfall in this regard and a sink-source hypothesis arising from these observations are also discussed. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2008.
53

Analise da expressão diferencial de genes de citros em resposta a infecção por Xanthomonas axonopodis pv. citri / Differential gene expression of citrus in response to infection by Xanthomonas axonopodis pv. citri

Camillo, Luciana Rodrigues 13 July 2006 (has links)
Orientador: Celso Eduardo Benedetti / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-07T07:02:38Z (GMT). No. of bitstreams: 1 Camillo_LucianaRodrigues_M.pdf: 5919875 bytes, checksum: 5cf571ac0a143a68d6340c3ad3c97f49 (MD5) Previous issue date: 2006 / Resumo: A doença cancro cítrico, causada pela bactéria Xanthomonas axonopodis pv. citri (Xac), emergiu como uma das principais ameaças à citricultura brasileira pois afeta todas as variedades comerciais de citros, diminuindo a produção e qualidade dos frutos e podendo se dispersar rapidamente em áreas de cultivo de citros. Entre os gêneros de Xanthomonas, foram encontrados muitos genes associados com patogenicidade e virulência, entretanto, pouco se conhece sobre os mecanismos envolvidos nas interações entre Xac e laranjeira e os genes envolvidos no desenvolvimento dos sintomas do cancro cítrico em folhas de citros (Citrus sinensis) em resposta à infecção por Xac. Neste trabalho, foi analizada a expressão diferencial de genes envolvidos no desenvolvimento do cancro cítrico em folhas de laranja, em resposta à infecção por Xac. Para tanto foram construídas duas bibliotecas de Hibridização Subtrativa Suprimida (SSH) com mRNAs de folhas infiltradas com Xac ou H20 após 10 dias de inoculação. O "screnning" das bibliotecas foi feito por dot blot e 17 genes diferencialmente expressos foram sequenciados e identificados por homologia no banco de dados ncbi-BLAST contra o banco de dados de EST de citros. A expressão gênica diferencial foi analizada por Northern Blot e PCR em tempo real (qPCR). Para complementar nossos dados, a expressão dos 17 genes diferenciais foi aI).alisada a partir de cDNAs de folhas de citros que foram infiltradas com Xac, H20 ou Xanthomonas axonopodis pv. aurantifolii (Xaa), que não é patogênica à laranja, mas causa cancro no limão galego. Nossos resultados demonstraram que Xac e Xaa induzem e reprimem o mesmo grupo de genes, porém em diferentes níveis. Nós identificamos que ambos patóg;enos alteram as vias de transdução de sinal de auxina, tráfico e fusão de vesículas, resposta de defesa e doença, síntese de proteínas e ciclo celular, metabolismo de carbono-nitrogênio e metabolismo secundário. A análise desses genes poderá ser de grande importância para o entendimento dos eventos que levam ao desenvolvimento dos sintomas do cancro / Abstract: The citrus canker disease, caused by Xanthomonas axonopodis pv. citri (Xac), has emerged as one of the major threats to the Brazilian citriculture because it affects all commercial citrus varieties, decreases the production and quality of the fruits and can spread rapidly in the citrus growing areas. The symptoms include canker lesions, leading to abscission of fruits and leaves and general tree decline. Within the genus Xanthomonas, several genes have been found associated with pathogenicity and virulence. However, little is known about the mechanisms involved in the Xac- citrus interaction and the development of the canker disease. In this work we analyzed the differential expression of genes involved in the development of the canker disease in sweet orange (Citrus sinensis) leaves in response to Xac infection. Therefore we constructed two Supression Subtracted Hybridization (SSH) libraries with mRNA from leaves infiltrated with Xac or water after 10 days of inoculation. The libraries were screnned by dot blot and the 17 differentially expressed genes were sequenced and identified through BLAST searches against the Citrus EST and protein databases. The differential gene expression was evaluated by Northem blot and Real Time PCR (qPCR). To complement our analysis, the expression of 17 genes was compared in cDNA samples from citrus leaves that had been infilt:r:ated with Xac, water or X axonopodis pv. aurantifolii (Xaa), wich is not pathogenic to orange but causes canker in key lime. Our results show that Xac and Xaa induce and repress a similar set of genes, however at different leveis. We found that both pathogens altered the pathways of auxin transport and signaling, vesicle trafficking and transport, cell cycle and protein synthesis, photorespiration and disease response. Further analysis of these genes will be of great importance to understand the events triggering the development of the canker symptoms / Mestrado / Genetica de Microorganismos / Mestre em Genética e Biologia Molecular
54

Tecnologias em combate : tradução e controvérsias na produção de laranja no Estado de São Paulo / Technologies in combat: : translation and controversies in the orange production in São Paulo State

Barbosa, Gabriela da Rocha, 1984- 21 August 2018 (has links)
Orientador: Leda Maria Caira Gitahy / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Geociências / Made available in DSpace on 2018-08-21T12:55:18Z (GMT). No. of bitstreams: 1 Barbosa_GabrieladaRocha_D.pdf: 1636339 bytes, checksum: 82302fd4bce22098a561100b57f17d28 (MD5) Previous issue date: 2012 / Resumo: O objetivo desta tese é entender o processo de transformação na cadeia produtiva da laranja no estado de São Paulo a partir da análise das mudanças tecnológicas introduzidas no setor produtor de laranja ao longo dos anos 2000. O estudo foca as mudanças tecnológicas relativas ao combate de doenças na lavoura citrícola, buscando analisar as controvérsias e as relações de poder presentes no processo de apropriação dessas tecnologias. As negociações em torno das formas de combate à doença da laranja conhecida como Huanglongbing (HLB ou greening) constituem o estudo de caso central na tese. O trabalho combinou a utilização de duas abordagens teóricas distintas: a cadeia global de mercadorias (global commodity chains) e a teoria ator-rede (actor network theory). A investigação também compreendeu a análise de dados empíricos a partir da realização de pesquisa de campo com diferentes estratos de produtores rurais de laranja e representantes institucionais da cadeia. Foi possível verificar que as políticas fitossanitárias de combate ao greening divulgadas pelos órgãos públicos e entidades representantes do setor não conseguiram conter o avanço da doença. Estes falharam em traduzir os interesses dos atores envolvidos na produção da laranja ao reduzir o controle a uma questão técnica desconsiderando o quadro de crise e de ampliação de assimetrias de poder na cadeia produtiva. Apesar da base técnica de controle de doenças adotada no setor apresentar sinais de esgotamento, medidas alternativas de controle esbarram nas exigências competitivas ditadas pelo modelo agrícola do setor e pela estrutura de governança da cadeia produtiva de laranja. Com o avanço do greening pelo estado de São Paulo desencadeia-se um processo de transformação sócio-técnica na cadeia produtiva da laranja cujas características principais são a crescente tecnificação do processo de produção e a ampliação das barreiras à permanência de produtores no setor / Abstract: The aim of this thesis is to understand the current transformation process in the orange production chain in Sao Paulo state on the basis of an analysis of technological changes in the sector over the years 2000. The study focuses on the technologies designed to combat diseases in citrus crops, trying to analyze the controversies and power relations present in the process of adoption of these technologies. Negotiations over the ways to combat the citrus disease known as Huanglongbing (HLB or greening) are the central case study in the thesis. The study combined the use of two distinct theoretical approaches: global commodity chains and actor network theory. The investigation also included the analysis of empirical data gathered through field research conducted with different strata of orange producers and institutional representatives of the productive chain. It was verified that the phytosanitary policies conducted by public entities and institutional representatives to combat the greening failed to contain the spread of the disease. These policies failed to translate the interests of the actors involved in orange production because they limited the combat of the disease to a technical issue ignoring the context of the crisis and the expansion of power asymmetries in the orange production chain. Despite the technical basis of disease control have shown signs of exhaustion, the adoption of alternative methods of control were restricted by the competitive requirements dictated by the "modern" agriculture pattern and the governance structure of the productive chain. With the spread of citrus greening disease in São Paulo state, there is the onset of a socio-technical transformation in the orange production chain, which main features are the increasing technification of the orange production process and the growing barriers to the stability of the current producers in the sector / Doutorado / Politica Cientifica e Tecnologica / Doutora em Política Científica e Tecnológica
55

Estudio de prefactibilidad para la instalación de una planta productora de bebidas nutritivas a base de quinua, kiwicha y naranja

Maticorena-Balvín, Fiorella, Larrauri-Rojas, Karol-Patricia January 2017 (has links)
El tema a desarrollar en la presente investigación, se refiere a la elaboración de una bebida a base de quinua, kiwicha y naranja con gran contenido de nutrientes. Este producto está desarrollado para las personas que cuidan su salud y disfrutan de aquellos productos nutritivos que contribuyan a una dieta equilibrada. / The subject to be developed in the present investigation, refers to the elaboration of a drink with quinoa, kiwicha and orange with great content of nutrients. This product is developed for people who take care of their health and enjoy those nutritious products that contribute to a balanced diet. / Trabajo de investigación
56

Estudo da formação de microemulsões contendo óleo essencial de Citrus sinensis (L.) Osbeck : efeito dos co-tensoativos e avaliação da interação das microemulsões com modelo de estrato córneo

Resende, Quênnia Garcia Moreno 13 November 2013 (has links)
Microemulsions (MEs) are dispersed systems, thermodynamically stable, isotropic, transparent, and stabilized by an interfacial film of surfactant compounds. In this study were obtained MEs from differents co - surfactant (ethanol - ET, isopropanol-ISO and propylene glycol - PG), Citrus sinensis (L.) Osbeck essential oil (CSEO), Tween 80 ® and phosphate buffer (pH 5.0). The co - surfactants were selected because they are tolerated by the skin. Therefore, the aim of the study was to evaluate the influence of co - surfactants in the formation of MEs containing Tween 80, CSEO and evaluate the influence of nifedipine (NFD) in the structure of systems formed. The MEs were obtained by constructing diagrams of pseudo-ternary phase in order to evaluate the influence of co-surfactant in the formation of MEs. The structural characterization of these systems was obtained by Polarized Light Microscopy (MLP), test electrical conductivity and Small angle X-ray scattering (SAXS). In each diagram, two formulations were selected, which was the criterion sense phase, in the O / A and bicontinuous, in which the NFD is incorporated. The formulations were evaluated by the techniques mentioned, to observe the influence of NFD and characterized by pH, droplet size, polydispersity index (PDI), surface tension and rheology. Interaction studies with model stratum corneum (SC) were performed using the techniques of differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). In the diagrams showed the greatest formation region of the MEs to the ISO (above 40 % T / Cot) instead of the co- surfactants ET and PG. When assessing the electrical conductivity has been observed that increasing the aqueous fraction resulted in an increase in conductivity. The SAXS curves demonstrated that all systems are characteristic of micellar structures and as the water content was added, it was observed the formation of larger structures. Therefore, from the results obtained, the NFD has been incorporated in the formulations selected. The MEs presented as stable systems, isotropic, translucent droplet size between 16 and 34 nm, PDI below 0.5 and pH in the range of 5.64 to 6.7, compatible with the skin and pH stability of the NFD. In conductivity tests for each co - surfactant, the MEs were classified as bicontinuous and O / A. The MEs exhibited reduced surface tension and the formulations containing ISO submitted a surface tension value (24,764 mN / m) lower than the other co - surfactants (ET - 29.512 mN/m PG - 31.784 mN/m), confirmed by the evaluation of the droplet diameter and obtaining the phase diagram. The MEs exhibited Newtonian behavior, with consistency indices (k) higher in formulations with higher proportions of T / Cot, result corroborated the structures observed by SAXS. The DSC and FTIR techniques have demonstrated the use of the MEs as permeation promoters, provided from interactions with SC model. Therefore, the diagrams have elucidated the effect of co- surfactant in the formation of MEs and the same interference suffered no NFD, suggesting their use as permeation enhancers on the skin on application. / As microemulsões (MEs) são sistemas dispersos, termodinamicamente estáveis, isotrópicos, transparentes, estabilizados por um filme interfacial de compostos tensoativos. Neste trabalho foram obtidas MEs a partir de diferentes co-tensoativos (etanol-ET, isopropanol-ISO e propilenoglicol-PG), óleo essencial de Citrus sinensis (L.) Osbeck (OECS), Tween 80® e tampão fosfato (pH 5.0). Os co-tensoativos foram selecionados por serem toleráveis pela pele. Assim, o objetivo deste trabalho foi avaliar a influência dos co-tensoativos na formação de MEs contendo Tween 80, OECS bem como avaliar a influência da nifedipina (NFD) na estrutura dos sistemas formados. As MEs foram obtidas pela construção de diagramas de fase pseudoternário com o propósito de avaliar a influência do co-tensoativo na zona de formação das MEs. A caracterização estrutural desses sistemas foi realizada por Microscopia de Luz Polarizada (MLP), ensaios de condutividade elétrica e espalhamento de raios-X a baixo ângulo (SAXS). De cada diagrama, foram selecionadas duas formulações, cujo critério foi o sentido de fases, na região de óleo-água (O/A) e bicontínuas, nas quais a NFD foi incorporada. As formulações foram reavaliadas pelas técnicas citadas, a fim de observar a influência da NFD, além de caracterizadas por pH, tamanho de gotícula, índice de polidispersividade (IPD), tensão superficial e reologia. Estudos de interação com modelo de estrato córneo (EC) foram realizados através das técnicas de Calorimetria exploratória diferencial (DSC) e Espectroscopia na região de infravermelho com transformada de Fourier (FTIR). Nos diagramas foi observada uma maior região de formação das MEs para o ISO (acima de 40% de T/Cot) ao contrário dos co-tensoativos ET e PG. Ao avaliar a condutividade elétrica foi observado que o aumento da fração aquosa proporcionou um aumento na condutividade. As curvas de SAXS demonstraram que todos os sistemas foram característicos de estruturas micelares e à medida que o conteúdo aquoso foi adicionado, observou-se a formação de estruturas com maiores dimensões. Logo, a partir dos resultados obtidos, a NFD foi incorporada nas formulações selecionadas. As MEs apresentaram-se como sistemas estáveis, isotrópicos, translúcidos, tamanho de gotículas entre 16 e 34 nm, IPD abaixo de 0,5 e pH na faixa de 5,64 a 6,07, compatíveis com a pele e pH de estabilidade da NFD. Nos ensaios de condutividade para cada co-tensoativo, as MEs foram classificadas como bicontínuas e O/A. As MEs apresentaram redução da tensão superficial, sendo que as formulações contendo ISO apresentaram um valor de tensão (24,764 mN/m) inferior aos demais co-tensoativos (ET- 29,512 mN/m e PG- 31,784 mN/m), confirmado pela avaliação do diâmetro de gotas e obtenção do diagrama de fases. As MEs apresentaram comportamento newtoniano, com os índices de consistência (k) maiores nas formulações com proporções mais elevadas de T/Cot, resultado que corroborou com as estruturas observadas por SAXS. As técnicas de DSC e FTIR demonstraram a utilização das MEs como promotores de permeação, a partir das interações proporcionadas com modelo de EC. Logo, os diagramas elucidaram a influência do co-tensoativo na área de formação de MEs e os mesmos não sofreram interferência da NFD, sugerindo a sua utilização como promotores de permeação em aplicação sobre a pele.
57

Estudo da formação de micelas e microemulsões contendo nifedipina : influência das fases na estrutura dos sistemas

Oliveira, Dayane Xavier de 03 February 2014 (has links)
Micelles (MIs) and microemulsions (MEs) are classified as stabilized systems by surfactants and are very similar with respect to their structure and physico-chemical properties. As for the applicability, they have been deployed by being able to carry drugs which have a limited systemic bioavailability by oral route. The formation of these systems is mainly dependent on the types of components used, making it important to study its influence on the structure. The goal of this study was to obtain and characterize micellar and microemulsion systems (containing essential oil of Citrus sinensis (L.) Osbeck as oil phase) stabilized by a nonionic surfactant (Tween 80) and short-chain cosurfactant (alcohol ethyl) which may be used as a delivery system for nifedipine (NFD a model drug) seeking to verify the influence of the phases and the interaction of the drug in the structure of these systems. Ternary and pseudoternary phase diagrams for MIs and MEs, respectively, and were obtained from the formation regions, formulations were selected for physico-chemical characterization and incorporation of NFD. The macro and microscopic aspects were evaluated using polarized light microscopy (MLP), measures pH, electrical conductivity and surface tension. The average droplet size was measured by dynamic light scattering (DLS) and small angle x-ray scattering (SAXS). The results demonstrated that such systems are stable, optically isotropic and transparent in the absence and presence of drug. The droplet size decreases with increasing amount of surfactant to MIs and the mixture surfactant/cosurfactant to the MEs. The influence of the cosurfactant in MIs was negligible. The increase of the amount of oily phase in MEs caused an increase in the droplet size. The presence of NFD no influence on the structure of MIs, but for the MEs increased droplet size, suggesting that the NFD is the internal phase of the MEs. The modeling by SAXS curves for MIs and MEs most diluted were made and showed the interaction between the NFD and systems, confirming the previous results. Studies by Fourier Transformed Infra Red (FTIR) confirmed the interaction between MIs and MEs with the stratum corneum (EC) , which allows the use of these systems as permeation enhancers of NFD. / As micelas (MIs) e as microemulsões (MEs) são classificadas como sistemas estabilizados por tensoativos e se assemelham bastante com relação a sua estrutura e propriedades físico-químicas. Quanto a sua aplicabilidade, elas têm sido destacadas por serem capazes de veicular fármacos que possuem uma biodisponibilidade sistêmica limitada por via oral. A formação destes sistemas é dependente principalmente dos tipos de componentes utilizados, tornando-se relevante o estudo da sua influência na estrutura. O objetivo do presente trabalho foi a obtenção e caracterização de sistemas micelares e microemulsionados (contendo óleo essencial de Citrus sinensis (L.) Osbeck como fase oleosa), estabilizados por um tensoativo não iônico (Tween 80) e um cotensoativo de cadeia curta (álcool etílico), que possam ser utilizados como sistema de liberação para a nifedipina (NFD, um fármaco modelo), buscando verificar a influência das fases e a interação do fármaco na estrutura desses sistemas. Diagramas de fase ternário e pseudoternário para MIs e MEs, respectivamente, foram obtidos e a partir das regiões de formação, formulações foram selecionadas para caracterização físico-química e incorporação da NFD. Os aspectos macro e microscópicos foram avaliados utilizando microscopia de luz polarizada (MLP), medidas de pH, condutividade elétrica e tensão superficial. O tamanho médio de gotículas foi avaliado por espalhamento dinâmico de luz (DLS) e espalhamento de raios-x a baixos ângulos (SAXS). Os resultados demonstraram que esses sistemas são estáveis, isotrópicos e opticamente transparentes na ausência e presença de fármaco. O tamanho das gotículas diminuiu com o aumento da quantidade de tensoativo para as MIs e de mistura de tensoativo/cotensoativo para as MEs. A influência do cotensoativo nas MIs foi praticamente desprezível. O aumento da quantidade de fase oleosa nas MEs ocasionou um aumento do tamanho das gotículas. A presença da NFD não exerceu influência na estrutura das MIs, entretanto para as MEs aumentou o tamanho de gotículas, sugerindo que a NFD se encontra na fase interna das MEs. Os modelamentos das curvas de SAXS para as MIs e MEs mais diluídas foram realizados e mostraram a interação existente entre a NFD e os sistemas, corroborando com os resultados anteriores. Estudos por espectrofotometria de absorção na região do infravermelho com transformada de Fourier (FTIR) comprovaram a interação das MIs e das MEs com o estrato córneo (EC), o que possibilita o uso destes sistemas como promotores de permeação da NFD.
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Orange bagasse as biomass for 2G-ethanol production = Bagaço de laranja como biomassa para produção de etanol-2G / Bagaço de laranja como biomassa para produção de etanol-2G

Awan, Almas Taj, 1984- 22 August 2018 (has links)
Orientador: Ljubica Tasic / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-22T23:34:19Z (GMT). No. of bitstreams: 1 Awan_AlmasTaj_D.pdf: 4796874 bytes, checksum: 185a66c389aae68c266f385689030ef0 (MD5) Previous issue date: 2013 / Resumo: Os biocombustíveis de segunda geração surgiram como fontes energéticas promissoras, podendo ser obtidos a partir de vários tipos de biomassa que não seja utilizada para alimentos. Um tipo de biomassa que apresenta baixo custo além de apresentar níveis elevados de carboidratos, é a biomassa obtida após o processamento da laranja (Citrus processing waste from oranges, CPWO). Há um grande interesse na exploração desta biomassa em termos da produção do bioetanol (etanol da 2G). Nosso trabalho visa melhorar os processos de hidrólise do CPWO comparando o rendimento do processo clássico de hidrólise ácida com aplicação de enzimas comerciais ou provenientes do microrganismo Xanthomonas axonopodis pv. citri, cepa 306 (um fitopatógeno). Os resultados obtidos com a presente investigação evidenciam que ocorreu a conversão bem-sucedida do CPWO em uma mistura de açúcares. A posteriori, os açúcares redutores que foram obtidos foram convertidos em bioetanol por meio da fermentação em mono- e co-cultura. Para tanto, foi empregada a espécie Saccharomyces cerevisiae e duas cepas de Candida parapsilosis IFM 48375 e NRRL Y-12969, sendo que as duas últimas foram isoladas a partir do bagaço da laranja. Os rendimentos em termos de bioetanol obtido nas fermentações aplicando co-culturas estavam ao redor de 50 a 62%, constituindo valores muito maiores comparados com os obtidos por cepas usadas individualmente. Além disso, os açúcares foram consumidos mais rapidamente (6 h), tornando tais processos atraentes em termos de custo e aplicações comerciais / Abstract: Second generation biofuels from renewable resources have come forth as a result of energy security coupled with diminishing fossil fuel resources. Lignocellulosic biomass is a renewable resource, which can be converted in to liquid transportation fuels. Utilization of agro-industrial waste for the generation of biofuels makes it a cleaner production (Green Chemistry). Brazil is the world¿s largest producer of oranges. The current project deals with Citrus Processing Waste from Oranges (CPWO), and obtaining valuable products such as bioethanol, hesperidin, and essential oil. The process of hydrolyzing CPWO was improved and the classical way of biomass saccharification, i.e. acid hydrolysis, was compared with the enzyme hydrolysis. In enzyme hydrolysis, apart from applying commercial enzymes, saccharification was also investigated with protein extracts of Xanthomonas axonopodis pv. citri strain 306 (Xac 306), a potent pathogen that causes Citrus canker disease. Later, the obtained reducing sugars were converted into bioethanol by submerged mono- and co-culture fermentations that involved three yeast strains: Saccharomyces cerevisiae, Candida parapsilosis IFM 48375 and NRRL Y-12969, the last two being isolated from bagasse. Results demonstrated successful hydrolyses by Xac enzymes that released high levels of fermentable sugars. Also during co-culture fermentation processes, it was noticed that ethanol yield was improved from 50% to 62% w/w (calculated on the basis of total dry matter contents) and sugars were consumed faster. Thus by employing co-culture fermentation strategy, apart from getting better bioethanol yields, fermentation time is also reduced that makes it a cost effective technique / Doutorado / Quimica Organica / Doutora em Ciências
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L'hybridation dans l'oeuvre de Jeannette Winterson / Hybridization in Jeanette Winterson's works

Mihajlovska, Lupka 16 November 2012 (has links)
Nous définissons l’hybridation littéraire comme la combinaison d’éléments a priori disparates aboutissant à la création d’un ensemble à la fois un et multiple, qui garde les traces de ses parties constitutives tout en étant autre, différent, nouveau. L’hybride englobe les sphères de représentation de ses éléments-parents tout en les dépassant. Par conséquent, l’hybridation tend vers l’extension de toutes les frontières, littéraires et culturelles, dans le but de nous offrir une vision du monde et du sujet toujours plus complète. Dans Oranges are not the Only Fruit, Sexing the Cherry, Written on the Body et The PowerBook de Jeanette Winterson, l’hybridation se manifeste à tous les niveaux du texte. L’hybridité physique et sexuelle des narrateurs est ainsi une des manifestations de leurs identités et vies plurielles et paradoxales. Ces hybrides incarnés (monstres, travestis ou androgynes) se construisant au fil de leurs histoires, qui s’inspirent toujours de récits antérieurs, narrateurs et narrations se démultiplient conjointement, s’entremêlent et se redéfinissent sans cesse. Le texte fluctue au gré de l’hybridation générique et de l’intertextualité. De l’entrecroisement de genres réalistes – tels que l’autobiographie, le récit historique ou le discours scientifique – et fictionnels – tels que le conte ou la romance – naît un hybride générique à résonances parodiques représentant la nature du sujet, de sa vie, de la réalité et de la vérité. Enfin, en hybridant des textes préexistants à des motifs personnels, l’auteur élabore une narration originale qui réécrit les schémas sexistes relayés par ses ancêtres et retranscrit sa vision de l’individu, du monde et de l’art. / We understand literary hybridization as the combination of seemingly different elements resulting in the creation of an entity that is simultaneously single and multiple. Indeed, while it is utterly other and new, the hybrid still shows the marks of its constituents. The hybrid incorporates its ‘parents’’ initial fields of representation while reaching beyond them. Consequently, hybridization is a process that pushes all boundaries, be they literary or cultural, to offer an ever more complete vision of the subject and his/her life. In Jeanette Winterson’s Oranges are not the Only Fruit, Sexing the Cherry, Written on the Body and The PowerBook, hybridization permeates every level of the text. Thus, the narrators’ physical and sexual hybridity is a manifestation of their plural and paradoxical identities. These hybrid creatures (monsters, transvestites or androgynous beings) build their identities through the stories they tell and that are always inspired by existing narratives. Therefore, the narrators and their narratives proliferate conjointly, intermix and redefine each other constantly. The shape of the text fluctuates with generic hybridization and intertextuality. Realistic narratives – such as autobiographical, historical or scientific discourses – and fictional ones – such as fairy tales or romances – interact to produce generic hybrids with parodic undertones that represent the nature of the subject, his/her life, reality and truth. Finally, by hybridizing existing texts and personal literary devices, the author elaborates original narratives that rewrite her ancestors’ sexist discourses and reflect how she perceives the individual, the world and art.
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L'hybridation dans l'oeuvre de Jeannette Winterson / Hybridization in Jeanette Winterson's works

Mihajlovska, Lupka 16 November 2012 (has links)
Nous définissons l’hybridation littéraire comme la combinaison d’éléments a priori disparates aboutissant à la création d’un ensemble à la fois un et multiple, qui garde les traces de ses parties constitutives tout en étant autre, différent, nouveau. L’hybride englobe les sphères de représentation de ses éléments-parents tout en les dépassant. Par conséquent, l’hybridation tend vers l’extension de toutes les frontières, littéraires et culturelles, dans le but de nous offrir une vision du monde et du sujet toujours plus complète. Dans Oranges are not the Only Fruit, Sexing the Cherry, Written on the Body et The PowerBook de Jeanette Winterson, l’hybridation se manifeste à tous les niveaux du texte. L’hybridité physique et sexuelle des narrateurs est ainsi une des manifestations de leurs identités et vies plurielles et paradoxales. Ces hybrides incarnés (monstres, travestis ou androgynes) se construisant au fil de leurs histoires, qui s’inspirent toujours de récits antérieurs, narrateurs et narrations se démultiplient conjointement, s’entremêlent et se redéfinissent sans cesse. Le texte fluctue au gré de l’hybridation générique et de l’intertextualité. De l’entrecroisement de genres réalistes – tels que l’autobiographie, le récit historique ou le discours scientifique – et fictionnels – tels que le conte ou la romance – naît un hybride générique à résonances parodiques représentant la nature du sujet, de sa vie, de la réalité et de la vérité. Enfin, en hybridant des textes préexistants à des motifs personnels, l’auteur élabore une narration originale qui réécrit les schémas sexistes relayés par ses ancêtres et retranscrit sa vision de l’individu, du monde et de l’art. / We understand literary hybridization as the combination of seemingly different elements resulting in the creation of an entity that is simultaneously single and multiple. Indeed, while it is utterly other and new, the hybrid still shows the marks of its constituents. The hybrid incorporates its ‘parents’’ initial fields of representation while reaching beyond them. Consequently, hybridization is a process that pushes all boundaries, be they literary or cultural, to offer an ever more complete vision of the subject and his/her life. In Jeanette Winterson’s Oranges are not the Only Fruit, Sexing the Cherry, Written on the Body and The PowerBook, hybridization permeates every level of the text. Thus, the narrators’ physical and sexual hybridity is a manifestation of their plural and paradoxical identities. These hybrid creatures (monsters, transvestites or androgynous beings) build their identities through the stories they tell and that are always inspired by existing narratives. Therefore, the narrators and their narratives proliferate conjointly, intermix and redefine each other constantly. The shape of the text fluctuates with generic hybridization and intertextuality. Realistic narratives – such as autobiographical, historical or scientific discourses – and fictional ones – such as fairy tales or romances – interact to produce generic hybrids with parodic undertones that represent the nature of the subject, his/her life, reality and truth. Finally, by hybridizing existing texts and personal literary devices, the author elaborates original narratives that rewrite her ancestors’ sexist discourses and reflect how she perceives the individual, the world and art.

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