Rene Francisco Boschi Gonçalves

Avaliação por SAXS e DSC das interações entre H2O e Renex-100

The aggregation behavior of the non-ionic surfactant Renex-100 in aqueous solutions and mesophases was evaluated by SAXS in a wide range of concentrations, between 20 and 30 °C. Complementary, water interactions were defined by DSC curves around 0°C. SAXS showed that the system undergoes the following phase transitions, from diluted to concentrated aqueous solutions: 1) isotropic solution of Renex aggregates; 2) hexagonal mesophase; 3) lamellar mesophase; and 4) isotropic solution. DSC analysis indicated the presence of interfacial water above 70wt%, which agreed with the segregation of free water to form the structural mesophases observed by SAXS bellow this concentration.

Modelagem da combustão da dinitramida de amônio por simulação computacional

In this work, the combustion process of ammonium dinitramide, ADN, has been modeled in two different situations: decomposition in open environment, with abundant air and decomposition in a rocket motor internal environmental conditions. The profiles of the two processes were achieved, based on molar fractions of the species that compose the products of ADN combustion. The velocity of formation and quantity of species in the open environment was bigger than the ones in the rocket motor environment, showing the effect of the different atmosphere in the reactions kinetics.

Reinforced Transparencies for Aerospace Application: Case Description

ABSTRACT: This paper describes the polycarbonate acrylic laminated development that can be applied in aeronautics and aerospace transparencies. The case studied is a laminated double-curved transparency (bubble form) used in an observation side window of a military aircraft. Side windows need strength and specific characteristics, similar to windshields, allowing the perfect visualization and image capture. Laminated transparencies composed by different materials have better qualities than the monolithic ones. This kind of transparency can offer high mechanical and chemical resistance, high transparency, no fragmentation and easy maintenance or recovery. A significant amount of information about materials and processes was jointed in order to build the reinforced transparency and validate this study. The final results were analyzed based on two points of view: mechanic resistance and, especially, optical quality.