84 resultados para Fotoquímica
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Dissertação mest., Química Orgânica, Universidade do Algarve, 2008
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Tese de dout., Química, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2008
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Tese dout., Ciências Agrárias, Produção Vegetal, Unidade de Ciências e Tecnologias Agrárias, Universidade do Algarve, 2000
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Tese de dout., Ciências Agrárias, Unidade de Ciências e Tecnologias Agrárias (Produção Vegetal), Univ. do Algarve, 2000
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Dissertação de Mestrado, Biologia Marinha, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2015
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Tesis (Maestría en Ciencias con Especialidad en Ingeniería Ambiental) UANL
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Tesis (Maestría en Ciencias Químicas en la Especialidad de Química Orgánica) U.AN.L.
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El arquitecto, don Miguel Fisac, autor del proyecto y director de la obras del Instituto Daza Valdés, facilita detalles acerca de ellas. El edificio tiene forma de U, y consta de cinco plantas y semisótano. Tiene secciones de óptica geométrica, física y teórica, espectros atómicos y moleculares, fotometría, óptica electrónica, oftalmológica, historia de la óptica, fotoquímica, rayos cósmicos, aula de conferencias, biblioteca, dirección y servicios generales. Destaca el sistema de módulos autónomos y la tabiquería transversal movible, que permitirá la transformación de cada laboratorio según las necesidades de las experiencias sucesivas, los departamentos técnicos especiales entre los que sobresalen los dedicados a estudio de visión nocturna. La superficie total del edificio es de 4845 metros cuadrados.
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A new practical method to generate a subspace of active coordinates for quantum dynamics calculations is presented. These reduced coordinates are obtained as the normal modes of an analytical quadratic representation of the energy difference between excited and ground states within the complete active space self-consistent field method. At the Franck-Condon point, the largest negative eigenvalues of this Hessian correspond to the photoactive modes: those that reduce the energy difference and lead to the conical intersection; eigenvalues close to 0 correspond to bath modes, while modes with large positive eigenvalues are photoinactive vibrations, which increase the energy difference. The efficacy of quantum dynamics run in the subspace of the photoactive modes is illustrated with the photochemistry of benzene, where theoretical simulations are designed to assist optimal control experiments
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La major conscienciació actual dels problemes de pol·lució que acompanyen les pèrdues de N del sòl cap a l'atmosfera ha reorientat les investigacions cap a un coneixement més profund dels processos implicats en les emissions dels compostos nitrogenats que comporten un major perjudici des d'un punt de vista ecològic així com els seus principals factors reguladors. La creixent preocupació per l'increment de la concentració atmosfèrica de N2O és deguda a les seves interaccions amb la fotoquímica atmosfèrica i el balanç de radiació de la Terra ja que intervé en la destrucció de la capa estratosfèrica d'ozó, contribueix a l'efecte hivernacle i participa de la pluja àcida. Es considera que els sòls són la principal font de N2O atmosfèric. Al voltant del 90% d'aquestes emissions són d'origen biòtic; els principals processos implicats són la desnitrificació i la nitrificació. L'emissió del N2O produït a través d'aquests dos processos es caracteritza pels diferents nivells de regulació que presenta ja que depèn de la taxa dels processos, de la proporció de N canalitzada per cada procés cap a la producció de N2O i del seu consum dins el mateix sòl el qual està relacionat amb les dificultats en el transport cap a l'atmosfera. Això comporta una gran dificultat a l'hora d'aprofundir en el coneixement de les emissions de N2O del sòl cap a l'atmosfera i de la seva regulació. El desconeixement dels nivells d'emissió de N2O i de la importància de la desnitrificació així com de la seva regulació tant en sòls agrícoles com naturals de les nostres contrades és el principal punt de partida dels objectius d'aquest treball.
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324 p.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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An evaluation project was conducted on the technique of treatment for effluent oil which is the deriving process to improve cashews. During the evaluation the following techniques were developed: advanced processes of humid oxidation, oxidative processes, processes of biological treatment and processes of adsorption. The assays had been carried through in kinetic models, with an evaluation of the quality of the process by means of determining the chemical demand of oxygen (defined as a technique of control by means of comparative study between the available techniques). The results demonstrated that the natural biodegradation of the effluent ones is limited, as result using the present natural flora in the effluent one revealed impracticable for an application in the industrial systems, independent of the evaluation environment (with or without the oxygen presence). The job of specific microorganisms for the oily composite degradation developed the viability technique of this route, the acceptable levels of inclusion in effluent system of treatment of the improvement of the cashew being highly good with reasonable levels of removal of CDO. However, the use combined with other techniques of daily pay-treatment for these effluent ones revealed to still be more efficient for the context of the treatment of effluent and discarding in receiving bodies in acceptable standards for resolution CONAMA 357/2005. While the significant generation of solid residues the process of adsorption with agroindustrial residues (in special the chitosan) is a technical viable alternative, however, when applied only for the treatment of the effluent ones for discarding in bodies of water, the economic viability is harmed and minimized ambient profits. Though, it was proven that if used for ends of I reuse, the viability is equalized and justifies the investments. There was a study of the photochemistry process which have are applicable to the treatment of the effluent ones, having resulted more satisfactory than those gotten for the UV-Peroxide techniques. There was different result on the one waited for the use of catalyses used in the process of Photo. The catalyses contained the mixing oxide base of Cerium and Manganese, incorporated of Potassium promoters this had presented the best results in the decomposition of the involved pollutants. Having itself an agreed form the gotten photochemistry daily paytreatment resulted, then after disinfection with chlorine the characteristics next the portability to the water were guarantee. The job of the humid oxidation presented significant results in the removal of pollutants; however, its high cost alone is made possible for job in projects of reuses, areas of low scarcity and of raised costs with the capitation/acquisition of the water, in special, for use for industrial and potable use. The route with better economic conditions and techniques for the job in the treatment of the effluent ones of the improvement of the cashew possesses the sequence to follow: conventional process of separation water-oil, photochemistry process and finally, the complementary biological treatment
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The petroleum industry deals with problems which are difficult to solve because of their relation to environmental issues. This is because amounts of residue are generated which vary in type and danger level. The soil contamination by non aqueous liquid phase mixtures, specifically hydrocarbon petroleum has been a reason for great concern, mainly the aromatic and polycyclic aromatic, which present risk to human health due to its carcinogenic and mutagenic character. The Advanced Oxidative Processes (AOP) are efficient technologies for destruction of organic compounds of difficult degradation and, often, they are present in low concentrations. They can be considered clean technologies, because there is no formation of solid by-products or the transfer of pollutor phases. This work focuses on the study of the degradation of petroleum industrial waste, by Advanced Oxidation Processes. Treatments tackling petroleum residues, contaminated soil, and water occurring in the production of petroleum reached the following Polycyclic Aromatic Hydrocarbons (PAH) degradation levels: solid residues 100% in 96 treatment hours; water residue - 100% in 6 treatment hours; soil contamination (COT degradation) - 50.3% in 12 treatment hours. AOP were effective in dealing with petroleum residues thus revealing themselves to be a promising treatment alternative
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Uma característica valorizada pelo setor alimentício é a propriedade de expansão dos grânulos de amido. Com este trabalho, teve-se por objetivo avaliar o efeito da concentração de ácido lático durante tratamento de modificação fotoquímica das féculas de batata-doce (Ipomoea batatas), biri (Canna edulis), mandioca (Manihot esculenta) e taioba (Xanthosoma sagittifolium). Pelos resultados obtidos neste experimento, nas condições em que este foi realizado, conclui-se que a concentração de ácido lático interferiu na propriedade de expansão das féculas de batata-doce, mandioca e taioba e não apresentou efeito na fécula de biri, devendo ser ajustado para cada tipo de fécula a ser modificada. Os índices de expansão obtidos nas diferentes féculas foram considerados baixos, quando comparados aos índices obtidos para fécula de mandioca modificada.