The effect of processing on structure and properties of polypropylene/clay nanocompsites

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Health-related quality of life of Gaza Palestinians in the aftermath of the winter 2008-09 Israeli attack on the Strip

<p><b>Background:</b> We document the health-related quality of life (HRQoL) of people living in the Gaza Strip 6 months after 27 December 2008 to 18 January 2009, Israeli attack.</p> <p><b>Methods:</b> Cross-sectional survey 6 months after the Israeli attack. Households were selected by cluster sampling in two stages: a random sample of enumeration areas (EAs) and a random sample of households within each chosen EA. One randomly chosen adult from each of 3017 households included in the survey completed the World Health Organization Quality of Life instrument, in addition to reported information on distress, insecurities and threats.</p> <p><b>Results:</b> Mean HRQoL score (range 0GÇô100) for the physical domain was 69.7, followed by the psychological (59.8) and the environmental domain score (48.4). Predictors of lower (worse) scores for all three domains were: lower educational levels, residence in rural areas, destruction to one's private property or high levels of distress and suffering. Worse physical and psychological domain scores were reported by people who were older and those living in North Gaza governorate. Worse physical and environmental domain scores were reported by people with no one working at home, and those with worse standard of living levels. Respondents who reported suffering stated that the main causes were the ongoing siege, the latest war on the Strip and internal Palestinian factional violence.</p> <p><b>Conclusion:</b> Results reveal poor HRQoL of adult Gazans compared with the results of WHO multi-country field trials and significant associations between low HRQoL and war-related factors, especially reports of distress, insecurity and suffering.</p&gt

Sensitivity-based Multifidelity Multidisciplinary Optimization of a Powered Aircraft Subject to a Comprehensive Set of Loads

Over the past decade, profound attention was given to exploring the benefits of engaging numerical multidisciplinary design optimization in aircraft design. Due to its importance, aerostructural wing design optimization is the most visited multidisciplinary problem in research institutes. To deal with this problem efficiently, gradient-based algorithms are popularly used. The complexity of the gradient-based aerostructural optimization, however, forced researchers to apply several simplifications to the problem formulation, such as neglecting engine effects or oversimplifying the loads process into few predefined load cases. The authors of this paper aim at running a gradients-based multidisciplinary design optimization of a commercial aircraft while including a powered engine and engaging a comprehensive, multi-fidelity loads process, subject to flutter as well as overall aircraft design constraints. The work, done by experts in the mentioned fields, is performed on a commercial aircraft provided by Airbus with many industry-relevant constraints. The results, showed the necessity to include a comprehensive loads process during the optimization. Additionally, it was concluded that engaging powered engines during the optimization is inevitable to come up with realistic designs; significantly different design geometries resulted when engaging a powered engine than when running the optimization with a flow-through nacelle

Determinants of birthweight; gender based analysis

The objective of this cross sectional study is to look at determinants of birth weight and their association with the gender of the baby in 2,795 full term children living in the occupied Palestinian territory, derived from a stratified random sample of 2,994 households in the West Bank and 2,234 households in the Gaza Strip. The response rate was 85%. Multivariable analysis using analysis of variance for mixed models showed that sex and birth order, maternal age and education and to a lesser extent region were determinants of birth weight for all children. The effect of maternal education on birth weight differed for female and male infants, tending to be relatively unchanged for male infants and with mean birth weights increasing with maternal education in female infants. The effect of birth order differed by maternal age, with mean birth weight increasing with maternal age for first and second births; but being unaffected by maternal age for infants of birth order greater than two. We conclude that birth weight is influenced by common biological determinants across cultures, but is also influenced by social, ethnic, and environmental factors that are culture specific, of which some might be gender related

Surrogate-Based Aerodynamic Shape Optimization of a Wing-Body Transport Aircraft Configuration

Aerodynamic shape optimization driven by high-fidelity computational fluid dynamics (CFD) simulations is still challenging, especially for complex aircraft configurations. The main difficulty is not only associated with the extremely large computational cost, but also related to the complicated design space with many local optima and a large number of design variables. Therefore, development of efficient global optimization algorithms is still of great interest. This study focuses on demonstrating surrogate-based optimization (SBO) for a wing-body configuration representative of a modern civil transport aircraft parameterized with as many as 80 design variables, while most previous SBO studies were limited to rather simple configurations with fewer parameters. The freeform deformation (FFD) method is used to control the shape of the wing. A Reynolds-averaged Navier-Stokes (RANS) flow solver is used to compute the aerodynamic coefficients at a set of initial sample points. Kriging is used to build a surrogate model for the drag coefficient, which is to be minimized, based on the initial samples. The surrogate model is iteratively refined based on different sample infill strategies. For 80 design variables, the SBO-type optimizer is shown to converge to an optimal shape with lower drag based on about 300 samples. Several studies are conducted on the influence of the resolution of the computational grid, the number and randomness of the initial samples, and the number of design variables on the final result