Cerâmicas arqueológicas possuem uma infinidade de dados sobre a dinâmica social e cultural dos indígenas do sítio Caninhas, SP. A superfície de fratura apresenta gradiente de cor, do ocre ao cinza escuro, quando da superfície para o centro da peça. Este aspecto é decorrente dos gradientes de temperatura gerados durante a queima da peça cerâmica, de forma que na superfície a combustão dos compostos orgânicos é completa (coloração mais clara) e na parte interna é incompleta (coloração mais escura). Foram realizadas análises composicionais por difração de raios X e mapeamento por EDS, sendo identificadas as fases ilita, quartzo e lutecita (região ocre) e ilita, quartzo, alumina-hidratada e lutecita (região cinza escura). Os resultados de EDS confirmaram a presença dos elementos químicos das fases identificadas por difração de raios X. As análises microestruturais por microscopia óptica e eletrônica por varredura sugerem a presença de raízes e restos de cerâmicas sinterizadas nas peças indígenas. Os resultados de dureza Vickers mostraram o quanto frágeis e heterogêneas são as cerâmicas arqueológicas, alcançando aproximadamente 203 HV (grãos de sílica) e 16 HV (matriz cerâmica).

Archaeological ceramics contain many data about social and cultural indigenous site Caninhas, SP, Brazil. The ceramics present a gradient of color (ochre to dark gray), when from the surface to the center of the piece. This behavior is associated with thermal gradients in ceramic pieces during the sintering process, resulting in a complete combustion of organic compounds at the piece surface (clear color) and incomplete burning inside the piece (dark color). Phase composition was analyzed by X-ray diffraction (XRD) and mapping by EDS, identifing the illite, quartz and lutecite phases (ochre region) and illite, quartz, hydrated alumina and lutecite phases (dark gray region). The results of EDS confirmed the chemical elements identified by X-ray diffraction. Optical microscopy and scanning electron microscopy analyses suggested the presence of roots and scrap of sintered pieces in indigenous ceramics. The Vickers hardness values showed the fragility and heterogeneity of archaeological ceramics, reaching approximately 203 HV in the grains of silica and 16 HV in the ceramic matrix.

The oxidation kinetics of a blend of zinc sulphide concentrates in a bench-scale fluidised bed reactor operated in batch regime was studied. The fractional conversion was determined by measuring the SO2 concentration in the exit gas using a chromatograph. The effects of the initial mass of the blend, airflow rate and temperature on fractional conversion were studied. The initial mass of the blend varied from 45 to 75 g, the airflow rate from 6 to 9 L/min and the temperature from 883 to 1213 K. The time for complete conversion was affected by the molar ratio of O2 to S fed into the reactor and by temperature. The oxidation reaction was controlled by surface chemical reaction of the unreacted core of the particles. The value of the activation energy, 87 kJ/mole, supports the contention that the reaction was chemically controlled.

The oxidation kinetics of a blend of zinc sulphide concentrates in a bench-scale fluidised bed reactor operated in batch regime was studied. This work involves the fluid dynamics characterisation of the bed during the reaction. Its purpose is to determine bed behaviour and to assess the experimental conditions used in the roasting experiments. The characterisation is derived from both fluid dynamics maps and an analysis based on the dynamics of gas bubble growth in the bed. Bed behaviour under any experimental condition is evaluated with the fluid dynamics maps. The transitions fixed/fluidised bed, fluidised bed/pneumatic transport and between several fluidisation regimes are obtained from curves of dimensionless gas velocity versus dimensionless particle diameters. The possibility of fluidisation in the slugging regime is verified by the dynamics of gas bubble growth in the bed.

Neste trabalho são destacadas as técnicas de separação e de purificação de terras raras por precipitação fracionada e troca iônica, além das técnicas usualmente utilizadas no controle analítico destes materiais. A aplicação destas técnicas é mostrada neste trabalho para a obtenção de óxido ou nitrato de cério com pureza > 99%. O principal objetivo é a obtenção de precursores à base de cério para o processamento de cerâmicas de zircônia-céria ou céria contendo terras raras. A disponibilidade de cloretos mistos, matéria-prima para a preparação de terras raras individuais, e o conhecimento das técnicas de separação, purificação e controle analítico de terras raras no IPEN, permite sua obtenção local para uso em pesquisa e desenvolvimento.

In this work techniques of fractioned precipitation and ion exchange for separating and purifying rare earth elements are outlined. Other techniques usually utilized in the analytical control of these elements are also briefly discussed. The application of these techniques for the preparation of cerium nitrate or cerium oxide of > 99% purity are demonstrated. The main purpose is to obtain cerium precursors for the processing of zirconia-ceria or ceria-rare earth ceramic materials. The raw material availability in the form of mixed chlorides, and the knowledge of these techniques at IPEN allows for obtaining these precursors in the local market for research and development purposes.

Mielopatia por HTLV-I (HAM) tem sido descrita como doença sistêmica caracterizada pelo acometimento de vários órgãos além do sistema nervoso. Neste registro, estamos relatando o envolvimento pulmonar em pacientes com HAM.

HTLV-I associated myelopathy has been described as a systemic disease characterized by manifestations in several organs outside the nervous system. We report inflammatory pulmonary involvement in patients with diagnosis of HAM.