Dynamical modeling of biogas production supported by an experimental anaerobic digestion process

This paper presents the development of a combined experimental and numerical approach to study the anaerobic digestion of both the wastes produced in a biorefinery using yeast for biodiesel production and the wastes generated in the preceding microbial biomass production. The experimental results show that it is possible to valorise through anaerobic digestion all the tested residues. In the implementation of the numerical model for anaerobic digestion, a procedure for the identification of its parameters needs to be developed. A hybrid search Genetic Algorithm was used, followed by a direct search method. In order to test the procedure for estimation of parameters, first noise-free data was considered and a critical analysis of the results obtain so far was undertaken. As a demonstration of its application, the procedure was applied to experimental data.

Relationship between blood pressure and psychological features of experience and behaviour among teachers

Purpose: Relationships between psychic features and psychophysical parameters, such as blood pressure, have a high relevance in research on coping with stress. We want to investigate the correlation between blood pressure and this psychic features. Methods: We investigated 79 teachers from high schools and secondary schools in and around Leipzig, Germany. Using the systolic blood pressure as an indicator, we built three groups: hypotonics, normotonics, and hypertonics. We assessed several health psychologically dependent variables and looked for differences between these groups (Chi-Square-Test). Results: Hypotonics experienced more stress and less planning and goal behaviour. Furthermore, they more often use physical exercises in order to increase their social well-being. Hypertonics, on the other hand, were driven by fear of loss of control and show a higher sense of feeling threatened. Conclusions: We could find for each group different relationships that are highly relevant to health. This results shows how psychological features and physiological regulation mechanisms are linked.