24 research outputs found
A global outlook to the interruption of education due to COVID-19 Pandemic: Navigating in a time of uncertainty and crisis
Uncertain times require prompt reflexes to survive and this study is a collaborative reflex to
better understand uncertainty and navigate through it. The Coronavirus (Covid-19) pandemic hit hard
and interrupted many dimensions of our lives, particularly education. As a response to interruption of
education due to the Covid-19 pandemic, this study is a collaborative reaction that narrates the overall
view, reflections from the K12 and higher educational landscape, lessons learned and suggestions from
a total of 31 countries across the world with a representation of 62.7% of the whole world population. In
addition to the value of each case by country, the synthesis of this research suggests that the current
practices can be defined as emergency remote education and this practice is different from planned
practices such as distance education, online learning or other derivations. Above all, this study points
out how social injustice, inequity and the digital divide have been exacerbated during the pandemic and
need unique and targeted measures if they are to be addressed. While there are support communities
and mechanisms, parents are overburdened between regular daily/professional duties and emerging
educational roles, and all parties are experiencing trauma, psychological pressure and anxiety to various
degrees, which necessitates a pedagogy of care, affection and empathy. In terms of educational
processes, the interruption of education signifies the importance of openness in education and highlights
issues that should be taken into consideration such as using alternative assessment and evaluation
methods as well as concerns about surveillance, ethics, and data privacy resulting from nearly exclusive
dependency on online solutions
Énergies renouvelables : les perspectives algériennes à l'horizon 2020 et les opportunités de coopération scientifique dans le cadre du NEPAD
Présentation PowerPoin
Performance improvement of large-scale solar water heating systems by using remote monitoring
Comparative study between solar and conventional heating-economic study and environmental impact
AbstractHome heating and production of domestic hot water are important items of expenditure and energy consumption. These are also sources of pollution and emission of greenhouse gases. This work presents a comparative study between conventional and solar heating of an individual house in Algerian climate conditions. For this purpose, we performed a general heat balance on various heat losses in house parts. Needs for heating and domestic hot water were also estimated. Based on these needs, sizing of the solar system has been developed. To compare the performances of solar and classic systems, we conducted an economic evaluation and determined the environmental impact. Although conventional energy is heavily subsidized in Algeria, the comparison of the cost of solar thermal kWh with other energies and the large quantities of CO2 avoided clearly show that economic and environmental benefits are in favor of solar heating development
Modélisation et Simulation numérique d'un cycle combiné gaz-vapeur
International audienceLa consommation de l’énergie est restée très longtemps stable lorsque l’homme ne l’utilisait quepour sa survie et ses besoins alimentaires. Une augmentation brutale des besoins en énergie estapparue, celle-ci ne cessait de croître de façon explosive sous l’effet conjoint de l’augmentation dela population et du développement industriel. Ce qui conduirait dans un proche avenir, à unépuisement des ressources énergétiques fossiles non renouvelables et à une dégradation del’environnement. Nous sommes alors contraints de faire la recherche d’autres ressources d’énergie.De préférence, nous nous orientons vers la recherche de ressources énergétiques qui soient durablestelle que les énergies renouvelables. Le solaire thermique, le photovoltaïque, la géothermie,l’énergie éolienne et la biomasse sont toutes des sources régénérables. Il est nécessaire de lesintégrer et de les adapter à nos besoins. L’un des problèmes à vaincre est celui du transport de cesénergies jusqu’aux points d’utilisation. Quand c’est possible, le transport de l’énergie électriquesemble le mieux adapté.Or, la production de l’électricité à grande échelle par conversion de l’énergie solaire est possible enconcentrant le rayonnement solaire, grâce aux systèmes de centrales CSP (Concentrated SolarPower) pour actionner un cycle thermodynamique efficace et produire de l’électricité en faisanttourner une ou des turbines à vapeur combinées à une ou des turbines à gaz « cycle combiné ». Cescentrales ‘gaz-vapeur’ sont conçues pour pouvoir récupérer les chaleurs dégagées dans les fuméesde la turbine à gaz, sortant à haute température pour être utilisées à la génération de la vapeur.L’objectif dans ce papier est de montrer l’optimisation et le rendement d’un tel cycle en faisant unesimulation numérique de ses constituants à l’aide d’un logiciel qui pourrait nous aider à modéliserles systèmes énergétiques, à établir un bilan exergétique et à connaître les éléments responsablesdes irréversibilités afin de chercher à les réduire. Les résultats ont montré qu’une centrale à unniveau de pression comporte de fortes irréversibilités internes
Economic and technical study of a hybrid system (wind-photovoltaic-diesel) for rural electrification in Algeria
This paper deals with design of hybrid energy system consisting of wind and photovoltaic with battery storage. A diesel generator is added to ensure continuous power supply and to take care of intermittent nature of wind and photovoltaic. The paper reports results of the technical-economic optimization study of photovoltaic/wind/diesel hybrid with battery storage in Algeria. The primary objective of this study is to estimate the appropriate dimension of stand-alone hybrid photovoltaic/wind/diesel with battery storage that guarantee the energy autonomy of typical remote consumer with lowest cost of energy. A secondary aim is to study the impact of renewable energy potential quality on the system size. The optimum dimensions of the system are defined for six sites in Algeria. In this context, a complete sizing model is developed in Matlab/Simulink V.6.5, able to predict the optimum system configuration. The simulation results indicate that the hybrid system is the best option for all the sites considered in this study. Thus, it provides higher system performance than photovoltaic or wind alone. It s shown that the principal advantage of photovoltaic/wind/diesel hybrid with battery storage are used all together, the reliability of the system is enhanced. The economic analysis has resulted in the calculation of kWh cost of energy for different types of resources and optimized cost of hybrid energy system. It s revealed too that the energy cost depends largely on the renewable energy potential quality. So, our objective for the optimization parameters is not the production cost but the offered service.Hybrid systems Modelling Simulation Rural electrification
Technical and economic assessment of hybrid photovoltaic/wind system with battery storage in Corsica island
EXPERIMENTAL STUDY OF THE PRODUCTION OF SOLAR HYDROGEN IN ALGERIA
<p>Hydrogen is a sustainable fuel option and one of the potential solutions for the current energy and environmental problems. In this study hydrogen is produced using a hydrogen generator with a Proton Exchange Membrane (PEM) electrolyser. An experimental study is done in the Center of Development of the Renewable Energy, Algiers, Algeria.</p><p>The experimental device contains essentially a photovoltaic module, a PEM electrolyser, a gasometer and the devices of measures of characteristics of the PEM electrolyser as well as two pyranometers for the horizontal and diffuse global radiance registration. This system in pilots scale is permitted on the one hand, to measured and analyzed the characteristics: of the PEM electrolyser for two different pressures of working (Patm and P=3 bar), on the other hand, to study the volume of hydrogen produces in the time with different sources of electrical power (generator, photovoltaic module, fluorescent lamp), the efficiency for every case is calculated and compared. We present in this paper the variation of the solar hydrogen flow rate produced according to the global radiance and according to the time for a typical day’s of August.</p