Encontrados 13 documentos, a visualizar página 1 de 2

Modelling and simulation of pear drying

In the present work a diffusion based model was adopted to represent the drying behaviour of pears in a continuous convective drier, taking into consideration the variation of the properties of the pears along drying. ; http://www.sciencedirect.com/science/article/B6TY8-4N5TN44-8/1/bbea80bec199264414c970bd6e95ab4c

Structural analysis of dextran-based hydrogels obtained chemoenzymatically

This work reports the results of structural analysis in novel dextran-acrylate (dexT70-VA) hydrogels generated chemoenzymatically. Porous structure as well as hydrogel surface and interior morphologies were evaluated by mercury intrusion porosimetry (MIP), nitrogen adsorption (NA), and scanning electron microscopy (SEM) analyses, as a function of the degree of substitution (DS), and initial water content used i...

Mercury intrusion porosimetry in pulp and paper technology

Mercury intrusion is frequently used for the characterization of porous materials, giving access to parameters such as porosity and pore size distribution as well as density (skeletal and bulk).The present work aims at studying the suitability of the mercury intrusion technique to evaluate the pore structure and related information of different kinds of woods used for pulp production, pulp handsheets and commer...

Effect of extended cooking and oxigen prebleaching on the surface energy of Euc...

Efeito do cozimento e da refinação nas dimensões transversais de fibras de E. g...

O presente trabalho visa à avaliação, por meio da técnica de microscopia confocal, das alterações nas dimensões da secção reta das fibras que ocorrem com o cozimento e com a refinação, bem como à análise da influência dessas alterações em algumas propriedades das pastas e das correspondestes folhas. Os resultados obtidos são interpretados, considerando o efeito daquelas operações na parede e no lúmen das fibras...

Primary and secondary fines from Eucalyptus globulus kraft pulps. Characterizat...

The main topic of this study is the characterisation of primary and secondary fines in a chemical kraft pulp. The former were removed from an unbeaten pulp and the latter from the corresponding decrilled pulp after beating, being their size distributions measured with the Coulter-Multisizer in terms of an equivalent volume diameter. Additionally, some morphological parameters of the fibres were also determined,...

Aplicação da microscopia confocal ao estudo de fibras de E. globulus : medição ...

Cellulose Depolymerisation and Paper Properties in E. Globulus Kraft Pulps

The aim of this work was to study the impact of cellulose depolymerisation on the beating potential and handsheet properties of the portuguese E. globulus kraft pulp. A homogeneous sample of eucalypt wood chips was cooked using different kraft pulping conditions (cooking temperatures and times, and sodium hydroxide and sodium sulphide concentrations) in order to obtain a wide variation for intrinsic viscosity o...

Aplicação da microscopia confocal ao estudo de fibras de E. globulus - medição ...

Este trabalho faz parte de um estudo mais amplo que envolve a determinação, por microscopia confocal, das dimensões de fibras de pastas de E. globulus, cultivado em Portugal. Em particular, nesta publicação é abordada a implementação e aplicabilidade da referida técnica, sendo apresentados os resultados relativos a duas pastas produzidas em condições de cozimento laboratorial significativamente distintas, anali...

Physical and chemical characterisation of some silicas and silica derivatives

An extensive study of four types of porous silica supports has been performed, with particular emphasis on their physical and morphological characteristics. These silicas were modified by reacting the surface silanol groups present with either 3-(trimethoxysilyl)propylmethacrylate or 3-glycidoxypropyltrimethoxysilane or 3-aminopropyltriethoxysilane, to produce derivatives with suitable functional groups for fur...