Dissertação de mestrado em Construção e Reabilitação Sustentáveis ; O presente trabalho de investigação teve como objetivo determinar qual o máximo benefício económico ao substituir, no betão, o cimento por cinzas volantes. O betão é um material amplamente utilizado pela população mundial, e como a população está a crescer, o consumo deste material também seguirá o mesmo sentido. O crescimento sustentável é um...
ABSTRACT Brightness stability is a very important property of beached cellulosic pulps. The impact of the final bleaching stage is assessed in this study for the purpose of understanding the fundamental reasons behind the improved brightness stability of bleached eucalypt pulp when the conventional chlorine dioxide stage (D) is replaced by an alkaline hydrogen peroxide stage (P). Particular emphasis was devoted...
Tese de mestrado integrado. Engenharia Informática e Computação. Faculdade de Engenharia. Universidade do Porto. 2009
Two industrial elemental chlorine free (ECF) bleaching sequences, D0(EOP)D1(EP)D2 and OQ(PO)DP, are compared with respect to the bulk content of lignin, carboxyl, hexeneuronic acids (HexA), and reducing groups after each bleaching stage. HexA groups contribute significantly to the total content of carboxyl groups, and their degradation during chlorine dioxide bleaching is reflected by a decrease of the carboxyl...
OBJECTIVE - To report the results of percutaneous occlusion of persistent ductus arteriosus with the Amplatzer prosthesis in 2 Brazilian cardiological centers. METHODS - From May 1998 to July 2000, 33 patients with clinical and laboratory diagnosis of persistent ductus arteriosus underwent attempts at percutaneous implantation of the Amplatzer prosthesis. The median age was 36 months (from 6 months to 38 years)...
Financiadores do RCAAP | |||||||
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |