Publications by authors named "Andrea O S Costa"

The literature reveals the application of the laws of thermodynamics for predicting life span and the effects of the physical activity level on longevity. But the vastly simplified literature models seem to suggest a reduction in duration of life with increased activity level, which is the opposite of medical recommendations, that means that exercises increase the longevity. The main objectives of this paper are to re-present the previous model, check and confirm the previous results and improve the model by formulating a simplified phenomenological relation between life span, specific entropy generation of the body (SEG-life, in MJ/kg.

View Article and Find Full Text PDF

Cement is one of the most used building materials in the world. The process of cement production involves numerous and complex reactions that occur under different temperatures. Thus, there is great interest in the optimization of cement manufacturing.

View Article and Find Full Text PDF

This paper reports the using of neural networks for water quality analysis in a tropical urban stream before (2002) and after sewerage building and the completion of point-source control-based sanitation program (2003). Mathematical modeling divided water quality data in two categories: (a) input of some in situ water quality variables (temperature, pH, O2 concentration, O2 saturation and electrical conductivity) and (b) water chemical composition (N-NO2(-); N-NO3(-); N-NH4(+) Total-N; P-PO4(3-); K+; Ca2+; Mg+2; Cu2+; Zn2+ and Fe+3) as the output from tested models. Stream water data come from fortnightly sampling in five points along the Ipanema stream (Southeast Brazil, Minas Gerais state) plus two points downstream and upstream Ipanema discharge into Doce River.

View Article and Find Full Text PDF