Comparison of different wind farm layouts for a 25 MW project in the south west of Algeria

The object of this work is to evaluate and compute the power potential of the KABERTEN site and to make the rigorous choice among different placements of wind turbines in order to decrease the wake effect and improve the power efficiency. Three proposals of wind farm layouts where all the turbines are faced to the prevailing wind have been used in the simulations. The results for individual and global energy yield as well as wake loss have been obtained and plotted. The wind Atlas Application Program (WASP) software of the Danish RISO laboratory is used in the study as a simulation tool to evaluate potential of the chosen site and to determine the best wind farm layout for a 25 MW projec

Orientation system of solar panels based on a robot manipulator

Solar energy is one of the most interesting renewable energies, as it is an inexhaustible natural accumulation. The electrical energy generated depends on the performance of photovoltaic panels that is based on the direction of sunlight. The position of the sun changes during the day, even during the year, which imposes a system of automatic orientation of solar panels for this purpose, several devices have been proposed and marketed. In our article, we focus on the adaptation of a robot manipulator for orientation and positioning of solar panels, applying for the control system, the model of the robot controller. First, we present the robotic system, which is a well-mastered, and his order was the subject of several studies and applications, and the model of the robot used for controlling the system. Finally, we give the simulation results in two modes: Mode fixed facing south with an inclination of 45° and the robot tracking mode following the elevation and azimuth movements with two decoupled movement. The results found show a gain in terms of solar energy collected measured about 51

Low incidence of SARS-CoV-2, risk factors of mortality and the course of illness in the French national cohort of dialysis patients

International audienceThe aim of this study was to estimate the incidence of COVID-19 disease in the French national population of dialysis patients, their course of illness and to identify the risk factors associated with mortality. Our study included all patients on dialysis recorded in the French REIN Registry in April 2020. Clinical characteristics at last follow-up and the evolution of COVID-19 illness severity over time were recorded for diagnosed cases (either suspicious clinical symptoms, characteristic signs on the chest scan or a positive reverse transcription polymerase chain reaction) for SARS-CoV-2. A total of 1,621 infected patients were reported on the REIN registry from March 16th, 2020 to May 4th, 2020. Of these, 344 died. The prevalence of COVID-19 patients varied from less than 1% to 10% between regions. The probability of being a case was higher in males, patients with diabetes, those in need of assistance for transfer or treated at a self-care unit. Dialysis at home was associated with a lower probability of being infected as was being a smoker, a former smoker, having an active malignancy, or peripheral vascular disease. Mortality in diagnosed cases (21%) was associated with the same causes as in the general population. Higher age, hypoalbuminemia and the presence of an ischemic heart disease were statistically independently associated with a higher risk of death. Being treated at a selfcare unit was associated with a lower risk. Thus, our study showed a relatively low frequency of COVID-19 among dialysis patients contrary to what might have been assumed