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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

Multimodalitní MR zobrazování patologických změn mozku u nemocných se schizofrenií / Multimodality MR Imaging of Pathological Changes in Schizophrenia

Slezák, Ondřej January 2021 (has links)
Multimodality MR imaging of pathological changes in schizophrenia Aim: To prove structural changes of the neocortex and white matter of the brain indicating connectivity disorder in early phases of schizophrenia. Material and methods: A prospective monocentric study comparing a cohort of patients after the first episode of schizophrenia (on average 15.6 days after the initial hospitalization) with a control group of healthy persons. Probands were examined using a complex MRI protocol. Twenty-six patients and twenty-four healthy persons were examined in total. Three dimensional T1 and T2 data and DWI data were analyzed using TBSS FA, FBA a surface- based morphometry. Results: Large areas of dispersively decreased FA were found in patients compared to control group using TBSS. Several fixels of decreased FD metric were found using FBA in the anterior commissure of patients and one sporadic fixel of decreased FDC metric was found in frontal white matter of the brain. No statistically significant areas of cortical surface area and cortical thickness differences were found using SBM. Conclusions: Large areas of decreased microstructural integrity of the white matter of the brain were found. However, it was not possible to specify the nature of its corruption using FBA. Our findings indicate the crucial role of...
2

Estudos do proceso de troca ionica do sistema multicomponente cobre-zinco-sodio utilizando a resina Amberlite IR 120 / Study of ion exchange process of the multicomponent system copper-zinc-sodium using the resin Aberlite IR 120

Borba, Carlos Eduardo 14 August 2018 (has links)
Orientadores: Reginaldo Guirardello, Edson Antonio da Silva / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-14T18:58:40Z (GMT). No. of bitstreams: 1 Borba_CarlosEduardo_D.pdf: 1593358 bytes, checksum: 8ae06b7d3dd4c535d777a874b5dab2a6 (MD5) Previous issue date: 2009 / Resumo: O aumento da produção industrial tem proporcionado a geração de efluentes aquosos contaminados com íons de metais pesados. Estes devem ser tratados antes de serem descartados no meio ambiente. Colunas de leito fixo podem ser eficientes na remoção de íons de metais pesados de meios aquosos. Para o projeto destes equipamentos são necessárias informações a respeito do equilíbrio do sistema, bem como informações a respeito dos efeitos de transferência de massa no sistema. Os principais objetivos deste trabalho foram a interpretação e obtenção de dados de equilíbrio de troca iônica dos sistemas binários Cu+2 - Na+, Zn+2 - Na+ e Zn+2 - Cu+2 e do sistema ternário Cu+2 - Zn+2 - Na+ e interpretação e obtenção de dados experimentais da dinâmica de troca iônica em coluna de leito fixo. Neste trabalho, foram realizados experimentos para a obtenção de dados de equilíbrio para os sistemas binários e para o sistema ternário. Estes experimentos foram conduzidos em sistema batelada na temperatura de 25°C. Foram também realizados experimentos de troca iônica em coluna de leito fixo para os sistemas binários Cu+2 - Na+ e Zn+2 - Na+ e para o sistema ternário. Em todos os experimentos foi utilizada a resina Amberlite IR 120 como trocador iônico. No tratamento dos dados experimentais de equilíbrio foram utilizadas a isoterma de Langmuir competitiva e a Lei da Ação das Massas (LAM) ideal e não ideal. A utilização da LAM não ideal exigiu o cálculo do coeficiente de atividade das espécies em ambas as fases. Para o cálculo do coeficiente de atividade dos íons na resina foi empregado o modelo de Wilson. Para o cálculo do coeficiente de atividade dos íons em solução foi empregado o modelo de Bromley. Os resultados mostraram que a isoterma de Langmuir competitiva e a LAM ideal representaram satisfatoriamente os dados de equilíbrio dos sistemas binários Cu+2 - Na+ e Zn+2 - Na+. No entanto, não representaram adequadamente o equilíbrio do sistema Zn+2 - Cu+2. A LAM não ideal representou apropriadamente o equilíbrio de todos os sistemas binários. O equilíbrio de troca iônica do sistema ternário foi representado satisfatoriamente pela isoterma de Langmuir competitiva e pela LAM não ideal, a qual envolveu os parâmetros dos sistemas binários para predizer o equilíbrio do sistema ternário. Para representar a dinâmica de troca iônica em coluna de leito fixo foi utilizado um modelo em que foram consideradas como etapas controladoras da transferência de massa a difusão no filme externo e a difusão nas partículas da resina. Neste modelo foi considerado equilíbrio termodinâmico na interface sólido-líquido, o qual foi representado pela isoterma de Langmuir competitiva e pela LAM não ideal. Os resultados mostraram que o modelo representou satisfatoriamente a dinâmica de troca iônica em todos os casos investigados. / Abstract: The increase in industrial production has provided the liquid effluent generation compound by heavy metal ions. These must be treated before being thrown in environment. Fixed bed columns may be efficient in the removal of these ions in aqueous environment. Therefore, to the project of these equipments, information related to the system equilibrium is essential as well as information about the effects of mass transfer in the system. The main goals of this paper were the achievement and interpretation of the equilibrium data related to the ionic exchange of the binary systems Cu+2 - Na+, Zn+2 - Na+ e Zn+2 - Cu+2 and of the ternary system Zn+2 - Cu+2 - Na+, and the achievement and interpretation of the ionic exchange dynamics in these systems in fixed bed column. In this work, experiments were made to obtain equilibrium data, for binary and ternary system. These experiments were made in batch system at the temperature of 25ºC. Experiments in ionic exchange in fixed bed column were made to the binary systems Cu+2 - Na+ , Zn+2 - Na+ and to the ternary system. In all of the experiments were used the resin Amberlite IR 120 as ionic exchanger. In the treatment of experimental equilibrium data, the competitive adsorption isotherm of Langmuir, the Mass Action Law (MAL) ideal and non ideal were used. The utilization of MAL non ideal required the calculus of activity coefficient of species in both phases. For the calculus of the ions activity coefficient in the resin, the Wilson model equation was used. To calculate the activity coefficient of ions in solution, the Bromley model equation was used. The results showed the competitive isotherm of Langmuir and the ideal MAL represented properly the equilibrium data of the binary systems Cu+2 - Na+ e Zn+2 - Na+. However, they hadn't properly represented the equilibrium of the binary system Zn+2 - Cu+2. The non ideal MAL represented properly the equilibrium of all binary systems. The ionic exchange equilibrium of the ternary system was represented properly by the competitive isotherm and non ideal MAL, which used the binary system parameters to predict the ternary system equilibrium. For the representation of the dynamic of ionic Exchange in fixed bed column, was used a model that considered the diffusion in external film, and diffusion on the resin particles as controller steps of mass transfer. In this model was considered thermodynamic equilibrium on the interface solid-liquid represented by the competitive isotherm of Langmuir and by the non ideal MAL. The results showed the model represented properly the dynamic of ionic exchange in all of the cases investigated. / Doutorado / Desenvolvimento de Processos Químicos / Doutor em Engenharia Química

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