Sensitivity analysis of urban flood flows to hydraulic controls

Water Qualit

STATIONS D’EPURATION A LITS FILTRANTS PLANTES DE MACROPHYTES WASTE WATER TREATMENT PLANTS WITH MACROPHYTES

L’utilisation de marais pour l’amélioration de la qualité de l’eau est une technique très ancienne. Depuis que l’homme rejettedes effluents pollués dans le milieu naturel, les marais ont été impliqués – volontairement ou non – dans l’épuration de ceux-ci.De nombreuses recherches sont actuellement menées afin de mieux comprendre les phénomènes intervenant dans le sol pourl’épuration, l’influence des conditions climatiques, les tailles et formes des lits, la charge hydraulique et le type de plantesutilisées. Le présent travail se veut une contribution à la mise en valeur des techniques d’épuration des eaux usées domestiquespar lits plantés de macrophytes

Lagrangian model for deposition from low-concentrated particles-laden turbulent jets

Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.This work presents a simple model that accurately predicts the deposition from low-concentrated particle-laden turbulent jets in different scenarios. Our proposed model is a developed Lagrangian model that takes advantage of the preferential concentration phenomenon. The unidirectional coupling (fluid- sediment) is used in the modelling. This choice is adopted because when the concentration of solid particles is small enough, it does not affect the hydrodynamic development of the jet. The deposition criterion states that the particle deposits when its settling velocity is greater than the vertical component of the entrainment velocity. Six experiments chosen from the available literature are used to validate the model. These experiments cover the cases of horizontal and inclined buoyant jets in stationary ambient, horizontal buoyant jets in coflow current and nonbuoyant horizontal jets in stationary ambient. Good agreement between the experiments and the obtained simulations is revealed. A sensitivity analysis study is conducted in order to investigate the role of the model main variables. We found that the most important variables are respectively the settling velocity of solid particles, the jet initial velocity, ambient velocity and the buoyancy forces.dc201

Experimental investigation and performance analysis of Archimedes screw generator

The generation of renewable energy with Archimedes screw generators (ASG) transforming potential energy of fluid flow into mechanical energy is a growing technology suitable for low-head hydraulic sites. This paper presents an improved theoretical model linking screw performance to screw geometry and flow conditions. This model takes into account leakages, friction losses and variable fill levels. The modelled values of torques and efficiencies are in a fairly good agreement with experimental results obtained for a laboratory-scale screw. The downstream screw immersion is shown to impact ASG efficiency and an optimal immersion level is proposed. It has been found that fluid friction on the screw is not negligible. The analysis shows that a single value of the friction coefficient is suitable for modelling the screw performance under various flow conditions. The leakage phenomenon at under-filling flow conditions and friction forces in complex turbulent flows need to be further studied

Profile of subjective quality of life and its correlates in a nation-wide sample of high school students in an Arab setting using the WHOQOL-Bref

<p>Abstract</p> <p>Background</p> <p>The upsurge of interest in the quality of life (QOL) of children is in line with the 1989 Convention on the Rights of the Child, which stressed the child's right to adequate circumstances for physical, mental, and social development. The study's objectives were to: (i) highlight how satisfied Kuwaiti high school students were with life circumstances as in the WHOQOL-Bref; (ii) assess the prevalence of at risk status for impaired QOL and establish the QOL domain normative values; and (iii) examine the relationship of QOL with personal, parental, and socio-environmental factors.</p> <p>Method</p> <p>A nation-wide sample of students in senior classes in government high schools (N = 4467, 48.6% boys; aged 14-23 years) completed questionnaires that included the WHOQOL-Bref.</p> <p>Results</p> <p>Using Cummins' norm of 70% - 80%, we found that, as a group, they barely achieved the well-being threshold score for physical health (70%), social relations (72.8%), environment (70.8%) and general facet (70.2%), but not for psychological health (61.9%). These scores were lower than those reported from other countries. Using the recommended cut-off of <1<it>SD </it>of population mean, the prevalence of at risk status for impaired QOL was 12.9% - 18.8% (population age-adjusted: 15.9% - 21.1%). In all domains, boys had significantly higher QOL than girls, mediated by anxiety/depression; while the younger ones had significantly higher QOL (<it>p </it>< 0.001), mediated by difficulty with studies and social relations. Although poorer QOL was significantly associated with parental divorce and father's low socio-economic status, the most important predictors of poorer QOL were perception of poor emotional relationship between the parents, poor self-esteem and difficulty with studies.</p> <p>Conclusion</p> <p>Poorer QOL seemed to reflect a circumstance of social disadvantage and poor psychosocial well-being in which girls fared worse than boys. The findings indicate that programs that address parental harmony and school programs that promote study-friendly atmospheres could help to improve psychosocial well-being. The application of QOL as a school population health measure may facilitate risk assessment and the tracking of health status.</p

Forecasting the effieniency or storm water tanks by 3d modelling : from experimantal tank to real-life works

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