Resumo: O presente trabalho, desenvolvido no âmbito do Programa de P&D ANEEL, projeto 6491-0301/2013, tem por objetivo avaliar como diferentes teores de contaminação por sulfetos interferem nas características microestruturais e mecânicas de pastas, quando estas são submetidas a duas diferentes condições de exposição: ciclo de molhagem e secagem e tanque aerado. Para a análise do mecanismo deteriorante foram avaliadas quatro séries de pastas, uma referência e três contaminadas por enxofre, por meio de ensaios no estado fresco (consistência e massa específica) e endurecido (resistência à compressão axial e a tração na flexão, variação dimensional e DRX). Ao final do período estudado (84 dias) notou-se que os ensaios auxiliaram no entendimento do mecanismo, mas que este ainda estaria em um estágio inicial.

Abstract: The present work, developed in the scope of the R&D Program of ANEEL, project 6491-0301/2013, aims to evaluate how different levels of sulfide contamination interfere with the microstructural and mechanical characteristics of the cement pastes when they are submitted to two exposure conditions: wetting and drying cycle and aerated tank. For an analysis of the deteriorating mechanism, four series of cement pastes, one reference and three contaminated by sulfur, were evaluated by non-fresh tests (consistency and specific mass) and resistance (axial compression and flexural tensile strength, dimensional variation and XRD). At the end of the study period (84 days) it was noted that the auxiliary assays did understand the mechanism but that it would still be at an early stage.

Resumen: El presente trabajo, desarrollado en el marco del Programa de P&D ANEEL, proyecto 6491-0301/2013, tiene por objetivo evaluar diferentes contenidos de contaminación por sulfatos que interfieren en las características microestructurales y mecánicas de mezclas, cuando estas son sometidas a dos diferentes condiciones de exposición: ciclo de mojado y secado y tanque aireado. Para el análisis del mecanismo deteriorante, se evaluaron cuatro series de mezclas, una referencia y tres contaminadas por azufre, por medio de ensayos en estado fresco (consistencia y peso específico) y endurecido (resistencia a la compresión axial y la tracción en la flexión, variación dimensional y DRX). Al final del período estudiado (84 días) se notó que los ensayos ayudaron en el entendimiento del mecanismo, pero que esta unión estaría en una etapa inicial.

A new dc hollow cathode plasma source has been assembled whith a conventional planar magnetron cathode used together with another plane cathode plate to form a hollow cathode cavity. The system comprises two cathode plates of aluminium separated by a distance d, one of them acting as target of the magnetron cathode, the other being an ordinary plate. The discharge anode is a metallic flange of the vacuum chamber. This leads to enhanced ionization in the cathode cavity region and enables the discharge to operate at significantly lower pressures than for a typical planar magnetron configuration. As a consequence, sputtered atoms can reach a substrate with minimum energy loss due to collisions with filling gas atoms. The discharge gas was a mixture of argon and nitrogen. AlN thin films were grown on silicon substrates, at ambient temperature, and characterized with respect to the structure and morphology by XRD and AFM analyses respectively. The structure and roughness of the AlN films were studied as a function of the deposition parameters.