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In recent years, there has been a great deal of interest in hybrid propulsion systems that provide power improvement solutions for watercraft. In order to be able to exploit the hybrid propulsion systems, one must first understand the principles of operation, its constituents as well as the parameters that influence its production and the means to control them. It is also essential to classify different types of batteries and panels according to their applications and environments. Our study will focus on the use of fuel cell, photovoltaic panels, a generator and a battery in the propulsion of a ship, which will choose an electrical topology that meets the constraints imposed. To realize a good exploitation of the hybrid system it is necessary to study all the equipment and to highlight the parameters on which they depend. Hence, it is necessary to think about the use of various sources to power ship propulsion system and that will allow better performance and strengthen navigation security. In this paper, we firstly studied, series and parallel hybrid propulsion configurations. Then we established the modeling of this system. Finally, we gave a numerical simulation of the proposed hybrid propulsion system operation.

This paper deals with electrical energy from multi-sources intended to feed a propulsion system of a boat. These energy sources consist of photovoltaic panels, fuel cells, supercapacitors and accumulator batteries. A study of different topologies of connections between these different sources and the propulsion engine of the boat allowed to retain the continuous Bus topology. In this work, we present the modeling of each energy source associated with its converter, as well as the dimensioning of these elements. Then, we give the overall electrical diagram with the different sources and the associated electrical converters which are all connected to a continuous Bus. This Bus feeds the synchronous propellant motor through a three-phase pulse-modulated control inverter. Numerical simulations were carried out in this work.

This article deals with the method of cathodic protection by imposed current. This technique reduces the rate of corrosion of a metallic material in the presence of an aqueous medium. Corrosion, its causes, its effects as well as the solution to combat this phenomenon, has been established in this paper. Indeed, the technique of protection by imposed current has been studied extensively in this work. The study and installation of a cathodic protection system imposed on-board the vedette, it is possible to determine the need for a DC current. This study ensures a good protection of the hull and a better location of the anodes. An imposed current regulation system has been studied. This system consists of measuring the potential of the boat’s hull by the reference electrode. With reference to this voltage value, the controller imposes the necessary current injected at the anode to maintain a fixed protection potential. In order to validate this study, simulations results under PSIM software dealing with protection of the hull of the vedette is finally presented.

In this work, the role of poly[2-methoxy-5-(2-ethyl-hexyloxy)-1,4-phenylene-vinylene] (MEH-PPV) as conducting polymer on the optical properties of the composite CdSe/ZnS core-shell quantum dots has been investigated. The optical properties of MEH-PPV polymer coated CdSe/ZnS composites are found to be dependent on the size of the quantum dot. A smaller CdSe quantum dot ensures a high exciton energy and smaller radiative lifetime. We found that the radiative lifetime in CdSe/ZnS embedded in MEH-PPV polymeric matrix is higher than that in CdSe/ZnS core-shell quantum dot. We also investigate the temperature dependence of the radiative lifetime over a temperature range from 100K to 300K; the temperature dependence of the radiative lifetime follows a quasi-exponential law. Consequently, the increasing temperature reduces the optical gap of MEH-PPV(CdSe/ZnS) polymer-CSQD. We found that the greater radiative lifetime corresponded to the larger values of temperatures.

Using the one band effective mass approximation model we computed the optical properties for the spherical shape CdSe/ZnS/SiO2 core/shell/shell quantum dot (CSSQD). We calculated the charge carrier energies and corresponding wave functions. We investigated the radiative recombination lifetime of CSSQD nanocrystal, we found that the radiative lifetime is increased when we added the SiO2 layer for the CdSe/ZnS core/shell quantum dots. Then we calculated the nonlinear susceptibilities associated with intersubband transitions in the conduction band for CdSe/ZnS/SiO2 spherical CSSQD, and the third-order susceptibilities for quadratic electro–optic effects as a function of the core, shell radii and pump photo energy involving the position of energy levels also have been analyzed. The results show that the dot size plays a fundamental role in determining the nonlinear optical properties of quantum dots. Indeed, we see that the variation of the size of CdSe core has a more remarkable effect on nonlinear susceptibilities than the change in the thickness of the ZnS layer, and the variation of the SiO2 layer thickness has a negligible effect.

Using the one band effective mass approximation model we computed the optical properties of the spherical shaped CdSe/ZnS and Cdse/ZnSe core–shell quantum dot (CSQD). For each structure we calculated the charge carrier energies and corresponding wave functions. We investigated the dependence of the carrier energies on various parameters of the CSQD, including its size. Then we calculated the radiative recombination lifetime for the two types of CSQDs nanocrystals. We found that as the size of the dot is increased the optical gap of CSQD is reduced, resulting in a reduction in electron energies and an increase in hole energies. We have shown that the radiative recombination lifetime in the CdSe/ZnS and CdSe/ZnSe CSQDs decreased by increasing the shell thickness around the core of the QD. We also showed that the radiative lifetime in the CdSe/ZnS is less than that in the CdSe/ZnSe CSQDs and is sensitive to the size and nature of shell of the semiconductor's material.

International audience; Solar cell based on conjugated polymer inorganic semiconductor are often designed to be structured in hybrid solar cell in objective to supply a large interface area for exciton dissociation. The main objective of this paper is to extract four electrical parameters such as the saturation current, the series resistance, the ideality factor and the shunt resistance from the measured current voltage characteristics in different conditions of annealing temperatures, annealing times, the weight ratio of Silicon nanowires, the thickness of photoactive layer and the treatment of Silicon nanowires with a fluorhydric acid solution HF for which hybrid solar cell had the best electrical properties. These parameters are extracted to simulate the current voltage of solar cell based on a thin film blend of Poly (N-vinylcarbazole) (PVK) and Silicon nanowires (SiNliVs). A good agreement between theoretical model and experimental measurement of electrical characteristics is obtained which illustrates the improvement that can supply the variation of different conditions on the characteristics of solar cells based on PVK/SiNWs.