19 resultados para Kern-Schale-Polymerisation


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Four tropical woods, were investigated to compare their performance and natural resistances to artificial weathering using the diffuse reflectance infrared Fourier transform spectroscopy (DRIFT). The species were garapeira (Apuleia leiocarpa), itaúba (Mezilaurus itauba) and tauari (Couratari sp.), woods traditionally indicated for exterior uses, and marupá (Simarouba amara), that served as reference. The samples were submitted to cycles of UV radiation (350 nm) and water until 2,000 h. The photodegradation processes of woods surfaces were accomplished monitoring the changes in the intensities associated to lignin (1508 cm-1) and carbonyl group (1736 cm-1) absorptions. The results have shown that lignin was the first component to be photodegradated, resulting in surfaces mainly composed by cellulose, after 2,000 h of UV irradiation. The processes of formation and lixiviation of carbonyl compounds were different for each species. The experimental conditions used in this work were too severe to evaluate the wood density and extractives content influences during the treatment.

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Behavior of mercury in soil profiles with archaeological black earth (ABE) and surroundings area (SA) from Sítio Ilha de Terra, Caxiuanã, can provide information on anthropogenic activity of the Amazonian habitat. The samples of ABE and SA soil profiles were submitted to mineralogical chemical (total and sequential) analysis. The data show that the Hg occurs mainly in goethite and kaolinite in the two soil profiles. The highest concentrations of Hg and Fe are observed in the SA profile. These results indicate that the prehistoric human occupation contributed to the decrease of the concentration of Hg in soil ABE from Caxiuanã.

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This paper reports the synthesis of nanostructured hydrogels of acrylamide by a two-step polymerisation process. The first step is performed by inverse microemulsion polymerization (water-in-oil) of N-isopropylacrylamide (NIPA), with these particles then added to aqueous solutions of acrylamide (AM), adding a crosslinking agent. The polymerization reaction is then initiated, thereby producing nanostructured hydrogels. We determined the capacity to absorb water, water and / or ethanol when nanostructured hydrogels were immersed in aqueous solutions with different concentrations of ethanol. It was found that the hydrogels were selective in absorbing water in all cases increasing with the ethanol concentration of the solutions.

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As Sessões Interativas em Educação Permanente em Saúde (Sieps) acontecem há quatro anos nas Unidades de Saúde da Família da Faculdade de Medicina de Petrópolis/Faculdade Artur de Sá Earp Neto (FMP/Fase). Baseiam-se nos princípios da educação permanente propostos pelo Ministério da Saúde e na metodologia de problematização. Buscam maior interdisciplinaridade dentro da unidade de saúde, trabalho em equipe, aproximação do usuário com o serviço e do estudante com a realidade. Esse trabalho objetiva compreender as reflexões feitas por estudantes de graduação em Medicina, Nutrição e Enfermagem e por usuários sobre as Sieps. Nesta pesquisa foram usados um questionário com base na escala de Likert, na amostra de estudantes, e uma entrevista, categorizada de acordo com a análise temática dentro da análise de conteúdo, usada na amostra de usuários. Foi possível concluir que os usuários e estudantes percebem positivamente as Sieps e que, em sua opinião e percepção, elas alcançam seus objetivos: melhoram o trabalho em equipe, enfatizando a interdisciplinaridade; acolhem bem os usuários; aproximam os estudantes da realidade das comunidades em que estão inseridos, com atualização e treinamento das equipes.