22 research outputs found

    Análise de imagens de séries temporais NDVI do sensor MODIS no Parque Nacional da Serra da Canastra

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    Monografia (graduação)—Universidade de Brasília, Instituto de Ciências Humanas, Departamento de Geografia, 2014.O presente estudo visa à delimitação das fitofisionomias vegetais presentes no Parque nacional da Serra da Canastra, o parque é uma unidade de conservação federal de grande importância para a conservação de nascentes de importantes rios brasileiros e proteção da grande biodiversidade encontrada nos arredores. Para tal procedimento as ferramentas de sensoriamento remoto foram escolhidas por serem as que melhor podem ajudar no processo. As imagens do sensor MODIS (Moderate Resolution Imaging Spectroradiometer) foram utilizadas e passaram pela geração do índice de NDVI (Normalized Difference Vegetation Index – Índice de Vegetação da Diferença Normalizada), após a realização de um processo de filtragem e classificação os resultados serão avaliados, o período escolhido foi entre os anos de 2000 a 2012. ______________________________________________________________________________ ABSTRACTThis research work is intended to delimit different vegetation types found inside the Serra da Canastra National Park. The park is a federal protected area where there is a need to conserve headwaters from important Brazilian rivers, and to protect biodiversity found around its area. In order to accomplish this procedure, remote sensing tools were chosen because it was thought to be the best way to do it. MODIS Images (Moderate Resolution Imaging Spectroradiometer) were used and processed on NDVI (Normalized Difference Vegetation Index), after a filtering and classifying process. The results will be evaluated. The period chosen goes from 2000 to 2012

    Preparation and characterisation of Dextran-70 hydrogel for controlled release of praziquantel

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    A hydrogel was developed from 70 kDa dextran (DEX-70) and praziquantel (PZQ) incorporated as a model drug. Biopharmaceutical properties, such as solubility and dissolution rate, were analysed in the design of the hydrogel. Furthermore, the hydrogel was also characterized by IR spectroscopy and DSC. Tests of the swelling rate showed that the hydrogel swelled slowly, albeit faster than the rate for the free polymer. In dissolution tests, the hydrogel released the drug slowly and continuously. This slow release was similar to that observed in the swelling tests and resulted in controlled release of the drug. Thus, this dextran is a suitable polymer for the development of hydrogels as vehicles for the controlled release of drugs.Um hidrogel foi desenvolvido a partir de dextrano 70 kDa (DEX-70) e praziquantel incorporado (PZQ) como fármaco modelo. Propriedades biofarmacêuticas, como solubilidade e velocidade de dissolução, foram analisadas no desenvolvimento do hidrogel. Além disso, o hidrogel também foi caracterizado por espectroscopia na região do infravermelho e calorimetria diferencial exploratória (DSC). Testes da taxa de intumescimento mostraram que o hidrogel intumesce lentamente, embora tenha sido mais rápido do que a taxa do polímero livre. Nos testes de dissolução, o hidrogel liberou o fármaco lenta e continuamente. Esta liberação lenta foi semelhante a observada nos testes de intumescimento e resultou em uma liberação controlada do fármaco. Assim, o dextrano 70 kDa é um polímero adequado para o desenvolvimento de hidrogéis como veículos para a liberação controlada de fármacos

    Obtenção e estudo de polímeros supramoleculares derivados de ácidos carboxílicos-meglumina em fase aquosa

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    Supramolecular polymers are monomer units held together by intermolecular interactions. The reversible nature of the interactions makes that supramolecular polymer be under thermodynamic conditions with the monomers. Thus the polymer chains undergo reversible breaking and reformation making the supramolecular material highly susceptible to temperature, solvents, pH, mechanical force, radiation and so on. Only a few compounds are able to undergoing supramolecular polymerization, once to obtain high polymerization degrees in bulk or in solution is required a strong and directional intermolecular force. When any type of organic acid is reacted with meglumine occurs the formation of a ionic pair, called carboxilate-meglumine compound. This study shows the amphiphilic carboxilate-meglumine compounds originated from fatty acids, suffer polymerization in aqueous phase by hydrophobic interaction and hydrogen bonds. The monomers adopt a lamellar array that result in a supramolecular polymer which form a tridimensional net where the water is immobilized forming a hydrogel. The relationship between polymerization and the carbonic chain of fatty acid allowed identify that the hydrophilic/hidrophobic is the property that controls the supramolecular polymerization of the carboxilate-meglumine compound in water. To prove that were used the estearic acids (octadecanoic) and oleic acid (9-cis-octadecanoic) that have chains of C18 size; and the saturated acids with distinct chains as underdecanoic (C11) and hexadecanoic (C16). The dynamic behavior of these materials was evaluated, once the intermolecular interactions of supramolecular polymer present a reversible character that is dependent of temperature and concentration. Finally, we studied the potential of stearate-meglumine hydrogel associated with antifungals (ketoconazole and fluconazole), as a strategy for inhibiting biofilm of Candida albicans, the fungus...Polímeros que possuem monômeros unidos via interações intermoleculares são definidos como polímeros supramoleculares. A natureza reversível das interações assegura que o polímero supramolecular exista em equlíbrio termodinâmico com seus monômeros. Isto implica que as cadeias do polímero podem romper-se e recombinar, tornando este material hábil em responder a mudanças externas ao sistema, como variação de temperatura, solvente, variação de pH, força mecânica, radiação, etc. Poucas substâncias são capazes de sofrer polimerização supramolecular, pois para que propriedades poliméricas sejam aparentes em fase sólida ou em solução, as interações intermoleculares devem ser fortes e direcionais. Reagindo qualquer tipo de ácido orgânico com um aminocarboidrato denominado meglumina é produzido o par iônico, genericamente chamado de carboxilato-meglumina. Este estudo mostra que compostos carboxilato-meglumina anfifílicos derivados de ácidos graxos polimerizam em fase aquosa via interações hidrofóbicas e ligações de hidrogênio. Os monômeros adotam um arranjo lamelar e o polímero supramolecular resultante, se estrutura em uma rede tridimensional de fibras onde a água é imobilizada formando um hidrogel. A correlação entre a polimerização e a característica da cadeia carbônica proveniente do ácido graxo precursor foi elucidada, permitindo identificar que o balanço hidrofílico/hidrofóbico é a propriedade que governa a polimerização supramolecular dos compostos carboxilato-meglumina em água. Para tanto foram utilizados ácidos análogos com cadeias de tamanhos iguais C18, neste caso, os ácidos esteárico (octadecanóico) e oleico (9-cis-octadecenóico) e também ácidos saturados de cadeias distintas, undecanóico (C11) e palmítico (hexadecanóico) (C16). O caráter reversível das interações intermoleculares no polímero supramolecular em função da..

    Caracterização e estudo do comportamento térmico dos adutos flunixina-meglumina e diclofenaco-meglumina

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    Aduto (do latin Adductus, “atraidos”) é o produto de uma adição direta de duas ou mais moléculas distintas, resultando em um produto de reação simples contendo todos os átomos de todos os componentes, com formação de duas ligações químicas e uma redução na multiplicidade da ligação em pelo menos um dos reagentes. Assim, aduto é uma nova espécie química resultante da união direta de moléculas individuais. A meglumina é um carboidrato que se caracteriza pela sua habilidade em formar adutos altamente solúveis em meio aquoso com ácidos carboxílicos. A indústria farmacêutica foi pioneira em explorar essa propriedade, aplicando-a no aperfeiçoamento de medicamentos já existentes. Diante desse contexto, os ácidos carboxílicos envolvidos na formação de adutos com a meglumina apresentam propriedades farmacológicas, mais especificadamente, pertencem à classe dos anti-inflamatórios não esteroidais (AINEs). Com relação à elucidação estrutural dessas espécies, um único trabalho é descrito na literatura o qual contempla o arranjo cristalino da flunixina-meglumina, primeiro aduto dessa classe a ser comercializado. Neste trabalho a flunixina-meglumina e o diclofenaco-meglumina, este último preparado como proposta do estudo, foram caracterizados a partir das técnicas Espectroscopia de Absorção na Região do Infravermelho (IV) e Ressonância Magnética Nuclear (RMN). O comportamento térmico da flunixina-meglumina e do diclofenaco-meglumina no estado sólido foi avaliado mediante as técnicas termoanalíticas Termogravimetria e Termogravimetria Derivada (TG/DTG); Termogravimetria e Análise Térmica Diferencial Simultânea (TG-DTA) e Calorimetria Exploratória Diferencial (DSC). Foi evidenciado que após a temperatura de fusão das respectivas amostras cristalinas, ocorre a formação de um material com comportamento polimérico sugerindo que os adutos...An adduct (from the Latin adductus, drawn toward) is a product of a direct addition of two or more distinct molecules, resulting in a single reaction product containing all atoms of all components, with formation of two chemical bonds and a net reduction in bond multiplicity in at least one of the reactants.Thus, an adduct is a new chemical specie that results from the direct union of individual molecules. Meglumine is a carbohidrate characterized by its capability to form soluble adducts in aquous solutions with carboxilic acids. Pharmaceuticals industry was the first to explore this property, with application to enhance drugs that already exists. In this context, carboxylic acids related to adducts formation with meglumine present pharmacological properties and are included in the class of nonsteroidal anti-inflamatory drugs (NSAIDs). Actually, it is not well understood the structural and chemical characteristics about adducts formed by association of meglumine and carboxylic acids. Only one work in the literature describes the cristaline sctructure formed by flunixin-meglumine adducts, the first compound in this class to go to market. In this work, two adducts (flunixin-meglumine and diclofenac-meglumine) were characterized by Infrared Absortion Spectroscopy (IR) and Nuclear Magnetic Resonance (NMR). Results sugest that the adduct formation of carboxylic acid-meglumine occurs by deprotonation of carboxylic acid and protonation of meglumine. Both adducts in solid state studied in this work were analyzed by Thermogravimetry – Differential Thermal Analysis (TG-DTA) and Differential Scanning Calorimetry (DSC). The results for DSC curves presented two cristaline forms for both adducts. Besides, it was noted that after the melting temperature of the respectives cristalines compounds, they present an self-assembly process wich leads to supramolecular polymers... (Complete abstract click electronic access below)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

    Thermal Behavior of Sr(II) and Ba(II)-Diclofenac Complexes in Solid State: Study of the Dehydration and Thermal Decomposition

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    Solid state compounds of general formula Sr(Diclof)(2)center dot 5.7H2O and Ba(Diclof)(2)center dot 4.8H2O were obtained. Thermogravimetry (TG), differential scanning calorimetry (DSC), X-ray diffraction powder patterns and microscopy analysis were used to characterize these compounds. Details concerning the dehydration and thermal decomposition as well as data of kinetic parameters have been described here. The kinetic behaviors of these stages were evaluated from several heating rates with samples masses of 2 and 5 mg in open crucibles under a nitrogen atmosphere. The results of the present study improve the knowledge on these compounds including their dehydration and thermal stability. The obtained data depend on the mass of the sample which results in two kinetic behavior patterns.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

    Thermal Behavior of Sr(II) and Ba(II)-Diclofenac Complexes in Solid State: Study of the Dehydration and Thermal Decomposition

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    Solid state compounds of general formula Sr(Diclof)(2)center dot 5.7H2O and Ba(Diclof)(2)center dot 4.8H2O were obtained. Thermogravimetry (TG), differential scanning calorimetry (DSC), X-ray diffraction powder patterns and microscopy analysis were used to characterize these compounds. Details concerning the dehydration and thermal decomposition as well as data of kinetic parameters have been described here. The kinetic behaviors of these stages were evaluated from several heating rates with samples masses of 2 and 5 mg in open crucibles under a nitrogen atmosphere. The results of the present study improve the knowledge on these compounds including their dehydration and thermal stability. The obtained data depend on the mass of the sample which results in two kinetic behavior patterns.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

    Thermal behavior of coffee oil (Robusta and Arabica species)

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    Coffee seeds are a source for obtaining oil which is used in the candy, soluble coffee, and cosmetics industries. The main purpose of this study was the investigation of the lipid profile and thermal behavior of the roasted and in nature coffee oil of Arabica and Robusta species, using thermogravimetry, differential thermal analysis, derivative thermogravimetry, differential scanning calorimetry (DSC), and modulated DSC. Details concerning the thermal decomposition as well as data of the kinetic parameters have been described here. The kinetic studies were evaluated from several heating rates with a sample mass of 10 mg in open crucible under nitrogen atmospheres. The obtained data were evaluated with the isoconversional kinetic method, where the values of activation energy (Ea/kJ mol-1) were evaluated in function of the conversion degree (α). In addition, this oil was evaluated by modulated DSC from 25 to -60 °C, where the transition phase behavior was verified. © 2013 Akadémiai Kiadó, Budapest, Hungary

    Thermal behavior of ara double dagger a oil (Psidium cattleianum Sabine)

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    The ara double dagger A is a well-known fruit, which belongs to the Myrtaceae family, Psidium cattleianum Sabine species, frequently found in the southern region of Brazil. The extraction of ara double dagger a oil was carried out from seeds, and the fatty acid profile of this oil indicates the predominant presence of linoleic acid (81.38%). Thermogravimetry, derivative thermogravimetry, and differential scanning calorimetry (DSC) were used to characterize this oil. In addition, this oil was evaluated by DSC from 25 to -60 A degrees C, where the crystallization behavior was verified. Details concerning thermal decomposition as well as data of kinetic parameters of these stages have been described here. The kinetic behavior of the thermal decomposition was evaluated from several heating rates with mass samples of 5 and 20 mg in open crucibles under nitrogen and synthetic air atmospheres.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

    Study of the thermal behavior of Al(III) and In(III)-diclofenac complexes in solid state

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    The Al and In-diclofenac compounds were prepared. Thermogravimetry (TG) and X-ray diffraction powder patterns were used to characterize these compounds. Details concerning the dehydration and thermal decomposition as well as data of kinetic parameters have been described here. The kinetic studies of these stages were evaluated from several heating rates with mass sample of 2 and 5 mg in open crucibles under nitrogen atmosphere. The results of the present study improve the knowledge on these compounds including their dehydration and thermal stability. The obtained data leads to a dependence on the sample mass, which results in two kinetic behavior patterns
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