A hydrodynamic model for biomass gasification in a circulating fluidized bed riser

This study presents a three-dimensional Computational Fluid Dynamic (CFD) model and experimental measurements of the hydrodynamics in the riser section of a Circulating Fluidized Bed (CFB) biomass gasifier consisting of a binary mixture of polydisperse particles. The model is based on multi-fluid (Eulerian-Eulerian) approach with constitutive equations adopted from the Kinetic Theory of Granular Flow (KTGF). The study first presents an assessment of the various options of the constitutive and closure equations for a binary mixture followed by sensitivity analysis of the model to the solution time step, cell size, turbulence and the alternative formulations of the granular energy equation. Accordingly, a robust and reliable hydrodynamic model is recommended and validated using conventional pressure measurements and Positron Emission Particle Tracking (PEPT) technique. Furthermore, the model predictions and experiments revealed evidence of the particle re-circulation within the lower part of the riser, which is an important feature contributing to rapid mass and heat transfer in a CFB gasifier. The present hydrodynamic model can be further developed; by incorporating appropriate reactions and heat transfer equations, in order to fully predict the performance and products of a CFB biomass gasifier

Mental health needs and services in the West Bank, Palestine

Background Palestine is a low income country with scarce resources, which is seeking independence. This paper discusses the high levels of mental health need found amongst Palestinian people, and examines services, education and research in this area with particular attention paid to the West Bank. Methods CINAHL, PubMed, and Science Direct were used to search for materials. Results and conclusion Evidence from this review is that there is a necessity to increase the availability and quality of mental health care. Mental health policy and services in Palestine need development in order to better meet the needs of service users and professionals. It is essential to raise awareness of mental health and increase the integration of mental health services with other areas of health care. Civilians need their basic human needs met, including having freedom of movement and seeing an end to the occupation. There is a need to enhance the resilience and capacity of community mental health teams. There is a need to increase resources and offer more support, up-to-date training and supervision to mental health teams