The goal of this manuscript is to use the Silvaco Atlas TCAD simulator to investigate the effect of some parameters on the current-voltage characteristics of a high-electron-mobility transistors devices based on AlxGa1-xN/GaN, Advanced AlxGa1-xN/AlN/GaN heterostructures with GaN channel layer and AlN spacer layer. It is demonstrated that numerical simulation can be used effectively in the development of HEMTs. We looked into the effect of the GaN thickness layer on the current-voltage characteristics, as well as the effect of the δ -doped layer within AlxGa1-xN barrier layer, the effect of the spacer thickness is also considered. Among the sample structures we used for our com-putations, our calculations reveal a low threshold voltage value and the maximum transconductance. Our structure with GaN channel layer thickness of 200 nm, Al content of x = 0.2 with a δ -doped layer of n = 5 x 1018 cm-3, we find that the maximum saturation current.

The breakdown paths and conditions of air-insulated rod-plane gaps under alternating voltages were investigated for plexiglass barrier inserted at different gap positions.In the present paper methods of the Modeling of the AC breakdown voltage in Point/Plane Air Gaps with insulating Plexiglas barrier are investigated by using the design of experiments method, An analysis based on experiments design method has been developed with indicates that,measures to contain tests of relevant information in the early stages of the short-time investigation were carried out on a one-time basis with a barrier varying in position and size. The results of our work are carried out at the High Voltage Laboratory of BISKRA University in the field of dielectric strength of air in system peak-barrier.

Numerical simulation of single junction and tandem solar cells-based copper indium gallium diselenide Cu(In,Ga)Se2 and silicon (c-Si) electrical characteristics have been accomplished by Solar Cell Capacitance Simulator (SCAPS 1-D) tool. The layered structure consisting of CIGS as top cell with a buffer layer of zinc-based oxysulfide Zn(O,S) and the bottom cell of c-Si junction has been investigated. The top and bottom single cells have demonstrated the conversion efficiency as 11.63 and 13.16%, respectively. The tandem designs exhibited a conversion efficiency of 25.68% resulted from the enhanced open-circuit voltage (VOC) as 0.90 V and short-circuit current density (JSC) as 36.99 mA/cm2. The cells were illuminated via AM 1.5 to investigate the current densities and external quantum efficiency (EQE). The simulations were optimized by adjusting the CIGS concentration and the thickness of semiconducting layers. Moreover, the effect of variation in temperature on the device performance has been investigated.

The purpose of this work is to design three optimal fractional-order PIλ Dµ controllers for regulating the at- titude of a three-axis satellite. The parameter gains of the controllers are tuned with the innovative Har- ris Hawks Optimizer (HHO). The state-space dynamic model of the satellite system is obtained by linearizing the nonlinear model around the Local Horizontal Lo- cal Vertical (LHLV) orbital frame. This allows for the model to be solved in state space. A study in which con- ventional PID controllers were used as a point of com- parison was carried out so that it could be shown how valuable the fractional order is in the design that was proposed.

Data warehouses have become, nowadays, at the core of decisional systems. The Index Selection Problem (ISP) is a challenging problem in data warehouses physical design. Regarding the NP-hard nature of this problem, existing solutions rely heavily on heuristics which constitutes a major drawback. In this paper, we propose a novel exact approach to the ISP based on Constraint Programming (CP). We formulate the problem as a Constraint Optimization Problem in a declarative way, then its resolution is automatically supported by a generic CP solver. Our proposed approach has also the advantage of being declarative, flexible, and expandable as it allows incorporating various kinds of user preferences, expressed as constraints, as well as choosing or defining new search strategies. Experimental results confirm our expectations and show that our approach scales well enough to solve much larger realistic instances in a faster and more effective way compared to well-known state-of-the-art approximation approaches.

The democratization of plug-in hybrid vehicles as well as purely electric vehicles implies a surplus of demand on the distribution networks. Vehicle-to-Grid aims to meet this increased demand by using vehicles no longer as simple loads for the electricity network but as players carrying out two-way energy exchanges. The work presented in this article proposes a real-time “Grid-to-Vehicle/Vehicle-to-Grid” control algorithm for an electrical distribution system. The results show that the system makes it possible to achieve energy gains shared between the actors while efficiently recharging the participating vehicles.