1000 resultados para Fourier, Charles, 1772-1837
Resumo:
Co-electrolysis of carbon dioxide and steam has been shown to be an efficient way to produce syngas, however further optimisation requires detailed understanding of the complex reactions, transport processes and degradation mechanisms occurring in the solid oxide cell (SOC) during operation. Whilst electrochemical measurements are currently conducted in situ, many analytical techniques can only be used ex situ and may even be destructive to the cell (e.g. SEM imaging of microstructure). In order to fully understand and characterise co-electrolysis, in situ monitoring of the reactants, products and SOC is necessary. Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) is ideal for in situ monitoring of co-electrolysis as both gaseous and adsorbed CO and CO2 species can be detected, however it has previously not been used for this purpose. The challenges of designing an experimental rig which allows optical access alongside electrochemical measurements at high temperature and operates in a dual atmosphere are discussed. The rig developed has thus far been used for symmetric cell testing at temperatures from 450[degree]C to 600[degree]C. Under a CO atmosphere, significant changes in spectra were observed even over a simple Au|10Sc1CeSZ|Au SOC. The changes relate to a combination of CO oxidation, the water gas shift reaction and carbonate formation and decomposition processes, with the dominant process being both potential and temperature dependent.
Resumo:
Trabalho que investiga a recepção dos Kinder - und Hausmärchen em Portugal, fruto duma aturada e minuciosa pesquisa documental. Com efeito, Teresa Cortez passa em revista os livros e publicações periódicas enquadrados entre 1837 — data do aparecimento das primeiras traduções de contos dos KHM, no periódico lisboeta Biblioteca Familiar e Recreativa — e 1910, data a que a autora estendeu a sua pesquisa. Cada incidência da presença dos contos dos Grimm em Portugal é cuidadosamente investigada, contextualisada e analisada, Assim, à medida que vemos surgir, primeiro esparsas em revistas destinadas a um público infantil, e sem indicação de autoria, traduções (do francês) dos KHM, vamo-nos inteirando sobre o epírito e motivações do seu aparecimento, quer partindo do estudo comparativo com o texto de origem, quer de um exame da publicação de chegada, alargando-se a pesquisa aos seus editores e autores. Todo o processo de recepção dos contos de Grimm vai sendo examinado pela autora à luz dos movimentos das últimas décadas do séc. XIX e primeira do séc. XX, nomeadamente o nacionalismo neo-romântico e o positivismo.
Resumo:
Thermal degradation and gaseous products evolving from the pyrolysis of sewage sludge, aimed at agricultural soil amendment, were investigated using Thermogravimetric Analysis in conjunction with Fourier Transform Infrared Analysis (TG-FTIR). The materials were studied in temperatures ranging from 30 to 800 ºC. Furthermore infrared spectra of sewage sludge samples were performed as a complementary technique. In parallel the sewage sludge was spiked with ibuprofen in order to test whether the mentioned techniques are able to detect the drug. Thermal analysis showed the range of 200-400ºC as the most characteristic for weight loss, corresponding with the organic matter volatilization, while the range of 500-800ºC was also characteristic and due to the volatilization of carbonates. On the other hand, ibuprofen-spiking tests identified at temperature range (150-250ºC) where the compound totally volatilizes, therefore, in this work, the detection of ibuprofen by TGA was established for concentrations higher than 0.5 g/kg sludge, concentration 102 times higher than the concentrations measured by other authors in regular sewage sludge (Martín, et al., 2010). A correlation has been found between the ibuprofen concentrations in the sludge and the intensity of the absorption bands, both for FT-IR spectra at the maximum emission temperature for ibuprofen (232ºC) as for the FT-IR spectra of the non-pyrolyzed samples.
Letter, Blacks Bluff, Wilcox County, AL, to Rebecca Spencer Powe, Chesterfield, SC, 1837 February 10