In this paper, versatile structures based on dissimilar metallic nano-particles (Ag, Au, Ti, Al) are proposed to enhance the ZnO thin film optical performance for both optoelectronic and environment monitoring applications. An Exhaustive study of the proposed structure including metallic nano-particles has been performed numerically, in order to evaluate the optical behavior of the proposed ZnO thin films against the conventional design for optoelectronic applications. The numerical computations reveal that the proposed design exhibits an outstanding capability in improving the overall device optical parameters. In addition, the proposed device with Al metallic nano-particles offers superior absorbance as well as lower reflectance as compared to the conventional design. These achievements can be attributed essentially to the localized surface plasma resonance phenomenon and the improved light trapping capability resulted from the optical confinement effect. The recorded results signify the crucial role of the proposed feature in improving the ZnO thin films optical performance, which makes it very promising to be used in the future high performance optoelectronic devices.

In this paper, versatile structures based on dissimilar metallic nano-particles (Ag, Au, Ti, Al) are proposed to enhance the ZnO thin film optical performance for both optoelectronic and environment monitoring applications. An Exhaustive study of the proposed structure including metallic nano-particles has been performed numerically, in order to evaluate the optical behavior of the proposed ZnO thin films against the conventional design for optoelectronic applications. The numerical computations reveal that the proposed design exhibits an outstanding capability in improving the overall device optical parameters. In addition, the proposed device with Al metallic nano-particles offers superior absorbance as well as lower reflectance as compared to the conventional design. These achievements can be attributed essentially to the localized surface plasma resonance phenomenon and the improved light trapping capability resulted from the optical confinement effect. The recorded results signify the crucial role of the proposed feature in improving the ZnO thin films optical performance, which makes it very promising to be used in the future high performance optoelectronic devices.

The multilevel multi-string inverter has gained much attention in recent years due to its advantages in lower switching loss, better electromagnetic compatibility, higher voltage capability, and lower harmonic distortion. Solar Energy is one of the favorable renewable energy resources and the multilevel inverter has been proven to be one of the important enabling technologies in photovoltaic (PV) utilization. As the number of levels increases, it is important to control more switches in parallel with their concurrent processing capability. This paper proposes an IGBT clamped three phase nine levels photovoltaic inverter topology with a multicarrier dual reference pulse-width modulated (PWM) control scheme. Four carrier waves of the fundamental frequency and different amplitudes are compared with two references (a sine wave and its opposite) for generating the control signals of the switches. Some DC/DC boost converters are used to amplify the voltage produced by the photovoltaic generators. Each of these converters is controlled by an MPPT algorithm in order to track the maximum power point of the GPV. Results of simulation in Matlab environment are given and discussed.

Nowadays, communications networks becomes an essential tool for exchange information. This fact allows having robust systems that ensures secure transfers against arbitrary intrusion. In literature, we encounter various encryption schemes that meet this requirement. In this paper, we interest to the chaos cipher map that achieved image encryption and its resistance against attacks based on genetic algorithm, an efficiency bio-inspired heuristic that used as powerful tool for resolution of complex combinatory problems. The skill of the approach is the use of such heuristic, and for a first time, in attack of image encryption schemes. We show its effectiveness by reporting results of some preliminary experiments, including a comparison with brute force attack.

Potassium dichromate (K2Cr2O7) is one of the most toxic elements to which man can be exposed at work or in the environment. The purpose of the current work is to compare the effect of K2Cr2O7 using variations in the dose, route of administration and duration of exposure in male and female Wistar albino rats with a special focus on biochemical parameters. K2Cr2O7 was subcutaneously administered alone (10, 50 and 100 mg/kg body weight) to female Wistar albino rats. Male rats received in their drinking water K2Cr2O7 30 mg/L/day) for 20 consecutive days. The Biochemical parameters were evaluated on days 3, 6 and 21 after subcutaneous (sc.) treatment in female rats and on days 10 and 20 after oral administration in male rats. The subcutaneous (s.c.) administration of 25 mg/kg of K2Cr2O7 to Wistar albino rats induced a slight change in plasma glucose levels during the experiment period. On the contrary, a significant decrease in plasma glucose levels was observed with 50 mg/kg mainly on days 3 (-26%) and 21 (-48%) after treatment compared to controls females rats. On the other hand, the higher dose provoked a significant increase in plasma glucose concentrations on days 6 (+31%) and 21 (+60%). similarly, the lower dose of chromium had no effect on the plasma urea levels. Conversely, a significant increase (122%) in this parameter was obtained during the first three days after treatment. In addition, a significant decrease in plasma glucose levels was observed with 50 mg/kg mainly on days 3 (-26%) and 21 (-48%) after treatment. On the other hand, the higher dose provoked a significant increase in plasma glucose concentrations on days 6 (+31%) and 21 (+60%). similarly, the lower dose of chromium had no effect on the plasma urea levels. Conversely, a significant increase in this parameter (122%) was obtained during the first three days after treatment. In addition, administration of 100 mg/kg of K2Cr2O7 by s.c markedly augmented the levels of plasma urea on days 3 (62%) and 6 (121%). Administration of 30 mg/L/day of K2Cr2O7 in the drinking water induced a significant augmentation in both of plasma glucose (27%) and urea (126%) during the first ten days of treatment. These results suggested that K2Cr2O7 administered subcutaneously or in the drinking water may induce harmful effects on biochemical parameters. Keywords : glucose, potassium dichromate, Wistar albino rat, urea.