Modelling dissolution of sparingly soluble powders

The present work deals with the simulation of the dissolution process of polydisperse powders. Three different size fractions of Ibuprofen were used to develop a model which assumes a diffusion layer thickness proportional to the particle diameter, up to a critical value, beyond which it is considered constant. The application of the resultant integrated equations to each size class of the primary particle size distribution leads to an almost perfect agreement between simulated and experimental dissolution profiles

Outdoor play as a mean to achieve educational goals: a case study in a Portuguese day-care group

This study aims to explore the pedagogical potential of outdoor play situations, considering the educational goals established in the Portuguese Pedagogical Guidelines for 0–3-year-old children (ongoing work), namely development of a sense of security and positive selfesteem; development of curiosity and exploratory impetus; and development of social and communication skills. Following a qualitative methodology, during a period of 9 months, the outdoor play experiences of 14 children from a day-care centre were observed and monitored and the professionals were interviewed. The data shows that outdoor experiences can contribute to the achievement of the educational goals, enlarging opportunities for creative play, problem solving, experimentation, inquiry, dialogues and collaboration. The achievement of the educational goals is facilitated through supportive and positive relationships with adults and peers, provision for proper equipment, and contact with nature. This study offers a deep insight into how educational policies can be put into practice in the outdoor area.publishe