A detailed study of the production of hydrogen and high added-value liquid products from the ethanol dehydrogenation reaction in the presence of sodium hydroxide (10% m m-1) was undertaken. Experiments were carried out in a batch reactor under different reaction conditions (temperature of 240 ºC and autogenous pressure between 45 and 72 bar), with analysis of the products obtained in the gas, liquid and solid fractions. The results showed that hydrogen was the major product formed in the gaseous fraction (maximum of 86.9%), while sodium acetate was the product in the solid fraction. Studies of the reaction mechanisms confirmed formation of the products identified in the gaseous and solid fractions. Mass spectrometry analyses of the liquid fractions revealed the presence of a series of compounds with molecular masses considerably higher than that of ethanol, which could be explained by the favoring of anionic polymerization reactions, under the experimental conditions employed.

RESUMO Demência rapidamente progressiva (DRP) é tipicamente definida como um declínio cognitivo que progride para prejuízo funcional severo em menos de 1-2 anos, geralmente em semanas a meses. O diagnóstico rápido e acurado é fundamental, já que muitas condições que levam a DRP são reversíveis. Métodos: Relatamos dois casos de neurosarcoidose que se apresentaram como DRP. Resultados: Caso 1: Uma mulher de 61 anos desenvolveu uma DRP associada a perda de acuidade visual. Em sete meses evoluiu com dependência para auto-cuidado. A ressonância magnética (RM) revelou lesões encefálicas temporais e supraselares. Evoluiu com melhora parcial após tratamento com metilprednisolona intravenosa em altas doses. Caso 2: Uma mulher de 43 anos que estava em tratamento para diabetes insipidus desenvolveu uma amnésia episódica severa um ano após o início dos sintomas cognitivos. A RM anterior mostrava uma lesão hipotalâmica, e ela recebeu tratamento oral com prednisona e ciclofosfamida. Houve redução dos achados da RM, porem sem melhora dos déficits cognitivos. A biópsia cerebral mostrou granulomas não caseosos e angeíte granulomatosa; o tratamento foi modificado para metilprednisolona intravenosa em altas doses, com resposta sintomática pobre. Conclusão: O diagnóstico de DRP por neurosarcoidose pode ser desafiador quando a doença está restrita ao sistema nervoso central. Nestes casos, a apresentação clínica da DRP associada a disfunção neuroendócrina e visual, exames de imagem com lesões hipotalâmicas e, em alguns casos, a biópsia cerebral são fundamentais para um diagnóstico correto. É possível que o diagnóstico e tratamento precoces poderiam ter trazido melhores resultados nesses pacientes.

ABSTRACT Rapidly progressive dementia (RPD) is typically defined as a cognitive decline progressing to severe impairment in less than 1-2 years, typically within weeks or months. Accurate and prompt diagnosis is important because many conditions causing RPD are treatable. Neurosarcoidosis is often cited as an unusual reversible cause of RPD. Methods: We report two cases of neurosarcoidosis presenting as RPD. Results: Case 1: A 61-year-old woman developed a RPD associated with visual loss. In seven months she was dependent for self-care. Magnetic resonance imaging (MRI) revealed temporal and suprasellar brain lesions. Treatment with high-dose intravenous prednisolone was associated with partial improvement. Case 2: A 43-year-old woman who was being treated for diabetes insipidus developed a severe episodic amnesia one year after onset of cognitive symptoms. Previous MRI had shown a hypothalamic lesion and she had been treated with oral prednisone and cyclophosphamide. There was reduction of the MRI findings but no improvement in the cognitive deficits. Brain biopsy disclosed noncaseous granulomas and granulomatous angiitis; treatment was changed to high-dose intravenous methylprednisolone, with poor symptomatic response. Conclusion: The diagnosis of RPD due to neurosarcoidosis can be challenging when the disease is restricted to the nervous system. In these cases, clinical presentation of RPD associated with neuroendocrine and visual dysfunction, imaging findings showing hypothalamic lesions and, in some cases, brain biopsy, are the key to a correct diagnosis. It is possible that earlier diagnoses and treatment could have led to a better outcome in these patients.

A resistência ao dano por choque térmico é uma característica importante dos materiais refratários visto que determina o desempenho e vida útil destes materiais em várias aplicações. Portanto é desejável a aplicação de técnicas mais sensíveis para avaliação do dano por choque térmico e monitoração da nucleação e expansão de trincas e microtrincas. O objetivo deste trabalho foi avaliar o potencial da caracterização da variação do amortecimento para quantificar o dano por choque térmico e para estimar o módulo de ruptura retido, complementarmente à caracterização do módulo de Young dinâmico. Foram estudadas as variações do amortecimento, do módulo de Young retido e a correlação destas variações com a resistência mecânica de um concreto refratário de alta alumina para distintas variações de temperatura e número de ciclos. As alterações encontradas no amortecimento foram proporcionais à resistência mecânica retida de forma similar a ocorrida para o módulo de Young retido. Também foram detectadas alterações no amortecimento não registradas no módulo de Young.

Resistance to thermal shock damage is an important characteristic in refractory materials, since it determines their performance and service life in many applications. Therefore, the use of more sensitive techniques is desirable to improve the evaluation of thermal shock damage and monitoring of nucleation and propagation cracks and microcracks.The aim of this work was to evaluate the potential of damping change characterization to quantify thermal shock damage and to estimate the retained mechanical strength in complement to the dynamic Young's modulus test. Variations in damping and retained Young's modulus and their correlation with the mechanical strength of a high alumina refractory castable were evaluated at different thermal shock temperatures and number of cycles. The changes in damping were proportional to the retained mechanical strength, similarly to the retained Young's modulus. Changes in damping were also detected which were not indicated by the Young's modulus measurements.

Indium can be recovered by treating residues, flue dusts, slags, and metallic intermediates in zinc smelting. This paper investigates the adsorption characteristics of indium and iron on an iminodiacetic acid chelating resin, Amberlite®IRC748 (Rohm and Haas Co.-USA). High concentrations of iron are always present in the aqueous feed solution of indium recovery. In addition, the chemical behaviour of iron in adsorptive systems is similar to that of indium. The metal concentrations in the aqueous solution were based on typical indium sulfate leach liquor obtained from zinc hydrometallurgical processing in a Brazilian plant. The ionic adsorption experiments were carried out by the continuous column method. Amberlite®IRC748 resin had a high affinity for indium under acidic conditions. Indium ions adsorbed onto the polymeric resin were eluted with a 0.5mol/dm³ sulphuric acid solution passed through the resin bed in the column. 99.5% pure indium sulfate aqueous solution was obtained using the iminodiacetic acid chelating resin Amberlite®IRC748.