Generating analysis topology using virtual topology operators

AbstractVirtual topology operations have been utilized to generate an analysis topology definition suitable for downstream mesh generation. Detailed descriptions are provided for virtual topology merge and split operations for all topological entities, where virtual decompositions are robustly linked to the underlying geometry. Current virtual topology technology is extended to allow the virtual partitioning of volume cells. A valid description of the topology, including relative orientations, is maintained which enables downstream interrogations to be performed on the analysis topology description, such as determining if a specific meshing strategy can be applied to the virtual volume cells. As the virtual representation is a true non-manifold description of the sub-divided domain the interfaces between cells are recorded automatically. Therefore, the advantages of non-manifold modelling are exploited within the manifold modelling environment of a major commercial CAD system without any adaptation of the underlying CAD model. A hierarchical virtual structure is maintained where virtual entities are merged or partitioned. This has a major benefit over existing solutions as the virtual dependencies here are stored in an open and accessible manner, providing the analyst with the freedom to create, modify and edit the analysis topology in any preferred sequence

A Prospective Open Trial of Guanfacine in Children with Pervasive Developmental Disorders

Objective: A common complaint for children with pervasive developmental disorder (PDD) is hyperactivity. The purpose of this pilot study was to gather preliminary information on the efficacy of guanfacine in children with PDD and hyperactivity. Methods: Children with PDD accompanied by hyperactivity entered the open-label trial if there was a recent history of failed treatment with methylphenidate or the child did not improve on methylphenidate in a multisite, placebo-controlled trial. Results: Children (23 boys and 2 girls) with a mean age of 9.03 (±3.14) years entered the open-label trial. After 8 weeks of treatment, the parent-rated Hyperactivity subscale of the Aberrant Behavior Checklist (ABC) went from a mean of 31.3 (±8.89) at baseline to 18.9 (±10.37) (effect size = 1.4; p < 0.001). The teacher-rated Hyperactivity subscale decreased from a mean of 29.9 (±9.12) at baseline to 22.3 (±9.44) (effect size = 0.83; p < 0.01). Twelve children (48%) were rated as Much Improved or Very Much Improved on the Clinical Global Impressions– Improvement. Doses ranged from 1.0 to 3.0 mg/day in two or three divided doses. Common adverse effects included irritability, sedation, sleep disturbance (insomnia or midsleep awakening), and constipation. Irritability led to discontinuation in 3 subjects. There were no significant changes in pulse, blood pressure, or electrocardiogram. Conclusions: Guanfacine may be useful for the treatment of hyperactivity in children with PDD. Placebocontrolled studies are needed to guide clinical practice

An Experimental comparison of two solar photovoltaic thermal (PVT) energy conversion system for production of heat and power

Abstract Two solar photovoltaic-thermal (PVT) energy conversion systems are described and their performance tested under laboratory conditions. One of these was a simple Flat Plate (FP-PVT) design, with headers and risers for heat removal the other a fixed linear axis Compound Parabolic Concentrating solar PVT (CPC-PVT) energy conversion system with a heat-pipe for removal of solar gain. Both had a low iron glass cover for high transmissivity of solar radiation, and polycrystalline silicon solar photovoltaic cells adhered to the absorber. Heat loss coefficient for the FP-PVT collector was measured as 4.1W/m 2 /K and 3.5W/m 2 /K for the CPC-PVT solar collector. These solar collectors were tested under steady state conditions using the solar simulator facility at the University of Ulster&apos;s Centre for Sustainable Technologies. The FP-PVT and the CPC-PVT had a combined efficiency of 66.8% and 53.4% respectively producing both heat and power