The monochromatic absorption coefficient of silicon, inducing the light penetration depth into the base of the solar cell, is used to determine the optimum thickness necessary for the production of a large photocurren...The monochromatic absorption coefficient of silicon, inducing the light penetration depth into the base of the solar cell, is used to determine the optimum thickness necessary for the production of a large photocurrent. The absorption-generation-diffusion and recombination (bulk and surface) phenomena are taken into account in the excess minority carrier continuity equation. The solution of this equation gives the photocurrent according to ab</span><span style="font-family:Verdana;">sorption and electronic parameters. Then from the obtained short circuit</span><span style="font-family:Verdana;"> photocurrent expression, excess minority carrier back surface recombination velocity is determined, function of the monochromatic absorption coefficient at a given wavelength. This latter plotted versus base thickness yields the optimum thickness of an n</span><sup><span style="font-family:Verdana;">+</span></sup><span style="font-family:Verdana;">-p-p</span><sup><span style="font-family:Verdana;">+</span></sup><span style="font-family:Verdana;"> solar cell, for each wavelength, which is in the range close to the energy band gap of the silicon material. This study provides a tool for improvement solar cell manufacture processes, through the mathematical relationship obtained from the thickness limit according to the absorption coefficient that allows base width optimization.展开更多
Convective heat transfer coefficients, materializing exchanges between solid wall (here typha) and its environment, influence its behavior under excitation pulse. Temperature of wall and its density of flow vary with ...Convective heat transfer coefficients, materializing exchanges between solid wall (here typha) and its environment, influence its behavior under excitation pulse. Temperature of wall and its density of flow vary with these coefficients according to its thickness (in depth). This study therefore focuses on the evaluation of convective heat transfer coefficient on front face and the optimal insulation thickness.展开更多
In many outbreaks, patients and healthcare workers are particularly at risk from nosocomial infections as a result of non-effective disinfection methods. With increasing incidence of viral infections such as severe ac...In many outbreaks, patients and healthcare workers are particularly at risk from nosocomial infections as a result of non-effective disinfection methods. With increasing incidence of viral infections such as severe acute respiratory syndrome, in one hand, and the increase in the rate of antibiotic resistant bacteria associated with nosocomial infections in other hand, there is a need to design novel engineering tools for inactivation of nosocomial pathogens. Ultraviolet germicidal irradiation (UVGI) is considered as a promising method to inactivate bacteria and viruses. This paper presents UV-C Based disinfection tools monitored by mobile application, designed for hospital and Epidemic Treatment Center. The evolution of the irradiation intensity over time w</span></span><span><span><span style="font-family:"">as</span></span></span><span><span><span style="font-family:""> evaluated, and the theorical disinfection duration for several nosocomial pathogens </span></span></span><span><span><span style="font-family:"">was </span></span></span><span><span><span style="font-family:"">determined. In the case of SARS-CoV2, less than 12 minutes were needed to achieve 99.99% viral reduction in a room of 36 sqm.展开更多
文摘The monochromatic absorption coefficient of silicon, inducing the light penetration depth into the base of the solar cell, is used to determine the optimum thickness necessary for the production of a large photocurrent. The absorption-generation-diffusion and recombination (bulk and surface) phenomena are taken into account in the excess minority carrier continuity equation. The solution of this equation gives the photocurrent according to ab</span><span style="font-family:Verdana;">sorption and electronic parameters. Then from the obtained short circuit</span><span style="font-family:Verdana;"> photocurrent expression, excess minority carrier back surface recombination velocity is determined, function of the monochromatic absorption coefficient at a given wavelength. This latter plotted versus base thickness yields the optimum thickness of an n</span><sup><span style="font-family:Verdana;">+</span></sup><span style="font-family:Verdana;">-p-p</span><sup><span style="font-family:Verdana;">+</span></sup><span style="font-family:Verdana;"> solar cell, for each wavelength, which is in the range close to the energy band gap of the silicon material. This study provides a tool for improvement solar cell manufacture processes, through the mathematical relationship obtained from the thickness limit according to the absorption coefficient that allows base width optimization.
文摘Convective heat transfer coefficients, materializing exchanges between solid wall (here typha) and its environment, influence its behavior under excitation pulse. Temperature of wall and its density of flow vary with these coefficients according to its thickness (in depth). This study therefore focuses on the evaluation of convective heat transfer coefficient on front face and the optimal insulation thickness.
文摘In many outbreaks, patients and healthcare workers are particularly at risk from nosocomial infections as a result of non-effective disinfection methods. With increasing incidence of viral infections such as severe acute respiratory syndrome, in one hand, and the increase in the rate of antibiotic resistant bacteria associated with nosocomial infections in other hand, there is a need to design novel engineering tools for inactivation of nosocomial pathogens. Ultraviolet germicidal irradiation (UVGI) is considered as a promising method to inactivate bacteria and viruses. This paper presents UV-C Based disinfection tools monitored by mobile application, designed for hospital and Epidemic Treatment Center. The evolution of the irradiation intensity over time w</span></span><span><span><span style="font-family:"">as</span></span></span><span><span><span style="font-family:""> evaluated, and the theorical disinfection duration for several nosocomial pathogens </span></span></span><span><span><span style="font-family:"">was </span></span></span><span><span><span style="font-family:"">determined. In the case of SARS-CoV2, less than 12 minutes were needed to achieve 99.99% viral reduction in a room of 36 sqm.