This paper presents a comparative study between two strategies for the direct torque control (DTC) of the permanent magnet synchronous generator (PMSG) based on wind energy conversion system (WECS). The first method is a conventional direct torque control DTC and it is based on hysteresis controllers where the torque and the flux are regulated by these controllers. The second one is direct torque control by space vector modulation strategy (DTC-SVM) where the torque and flux are regulated by PI controllers. The simulation results are implemented by using MATLAB/SIMULINK. The main feature of the proposed (DTC-SVM) strategy is the reduction of torque and flux ripples. The proposed approach can be considered as an alternative solution to the control of PMSG.

This study investigated insect diversity of olive (Olea europaea Linnaeus (Oleaceae)) groves grown in arid and semiarid climates in northeastern Algeria. Using several sampling techniques, a total of 1326 insect specimens were collected and identified into 151 species, 124 genera, 65 families, and 10 orders. Hymenoptera and Coleoptera were quantitatively the most abundant, whereas the dominant functional feeding groups were phytophages then predators. The entomofauna included several olive pests such as Bactrocera oleae (Rossi) (Diptera: Tephritidae), Parlatoria oleae (Colvée) (Hemiptera: Diaspididae), Euphyllura olivina (Costa) (Hemiptera: Liviidae), and Liothrips oleae Costa (Thysanoptera: Phlaeothripidae). Although insect diversity parameters recorded for both observed and expected species richness were higher in olive groves grown under semiarid compared with arid climate, the completeness rate of species richness obtained using the nonparametric incidence estimators was higher in arid olive groves. Generalised linear models showed that the number of individuals and species richness varied significantly between climates (P < 0.01), whereas the variation of the rest of diversity parameters was not significant. Diversity traits of insect assemblage of each climatic region were positively correlated. Besides, the Mantel permutation test revealed similar patterns (r = 0.91, P < 0.0001) between correlation matrices of the two climates. When increasing the number of samples, species richness extrapolation revealed that diversity is expected to increase by 130% in olive groves grown under arid climate and 93% in semiarid climate. These increases are related to continuous appearance of rare and scarce insects as demonstrated by species rarefaction curves. Even with high evenness values of insect communities, similarity was low between climate indicating the rarity and scarcity of populations.

The problem of setting and coordination of Directional Over-Current Relay (DOCR) is a highly constrained optimization problem that has been solved as a linear programming problem. The calculation of the time dial setting (TDS) and pick up current (I P) setting of the relays is the core of the coordination. This paper calculates the TDS by choosing one of the available pick up current settings as the predetermined value, in this paper it will be set at 0.5, 1 and 1.5. The LP Dual simplex method is used to determine the optional TDS of the relays in compensated system by series FACTS devises ie Thyristor Controlled Series Capacitor (TCSC). A sample system of IEEE 33 bus distribution system is used to demonstrate the feasibility and efficiency of the developed method.

Securing the network communication represents one of the most important challenges in wireless sensor networks. The key distribution problem has been widely discussed in classical wireless sensor networks contrarily to heterogeneous ones. HWSNs (Heterogeneous Wireless Sensor Networks) have optimized the network capability and opened new security opportunities by introducing high resource capacity sensor nodes in the network. In this paper, an efficient dynamic authentication and key Management scheme is proposed for heterogeneous WSN. The main idea is to provide a single lightweight protocol for both authentication and key establishment while optimizing the security level. The key distribution algorithm is based on preexisting information to generate dynamic keys and does not require any secure channel and sharing phase which improves the security, energy efficiency and reduces the memory consumption. Experimental results have confirmed the performances of our mechanism compared to some of the existing security protocols.

In this paper, a new Au/p-Si Schottky Barrier Diode (SBD) based on Indium Tin Oxide (ITO) intermediate thin-film is proposed and experimentally investigated by including the annealing temperature effect. We elaborated the Au/ITO/p-Si structure by means of RF magnetron sputtering technique and compared its electrical properties with the conventional Au/p-Si SBD. The role of the annealing process at 200 and 400 °C as well as the ITO interface thin-layer in improving the SBD basic electrical parameters is analyzed. The characterization has revealed that a higher Schottky barrier (ϕb) of 0.79V is achieved. Moreover, close to unit ideality factor of (n = 1.25) and reduced density of states (Nss = 1.5 × 1012cm-2) and series resistance of (Rs = 32Ω) are recorded. These achievements can be attributed to the enhanced interface quality provided by introducing the ITO thin-film. Moreover, the annealing process enables improved crystallinity and allows efficient rearrangement of atoms at the interfaces. The thermal stability behavior of the investigated designs is analyzed, where new Figure of Merit (FoMs) parameters are proposed. It is found that the annealed Au/ITO/p-Si structure offers the opportunity for suppressing the degradation related-heating effects. Therefore, the proposed Au/ITO/p-Si SBD pinpoint a new path toward achieving superior electrical characteristics and improved thermal stability, which makes it a potential alternative for high-performance microelectronic and optoelectronic applications.

In this paper, a transparent conductive ITO/Ag/ITO (IAI) multilayer structure with a high Haacke Figure of Merit (FoM) far surpassing those found up to now is experimentally demonstrated. An optimized IAI multilayer electrode was elaborated by means of RF magnetron sputtering technique. The structural and electrical characteristics of the prepared tri-layered design were investigated. The influence of the annealing process on the IAI electrode performance was also carried out. Unlike the IAI structure as-deposited, it was revealed that the annealed samples maintained an average transparency superior than 89%. This behavior indicates the effectiveness of the thermal treatment for ensuring favorable light management. In addition, it was found that the annealing process paves a new path toward improving the electrode conductivity, where the heat treated electrode at 600°C yielded a very low sheet resistance of 2.95Ω × sq-1. Therefore, by well optimizing both IAI geometry and annealing conditions, we were able to elaborate high-quality coating with a superior FoM of 120.8 × 10-3Ω-1. This makes the sputtered IAI multilayer design a suitable alternative to the conventional ITO-based electrodes for optoelectronic and photovoltaic applications.

The resonant characteristics of superconducting rectangular microstrip patch antenna witha superstrate layer are investigated using a full-wave spectral analysis in conjunction with the complexresistive boundary condition. The complex surface impedance of superconducting patch is determinedusing London’s equation and the two-fluid model of Gorter and Casimir. Numerical results using thefull-wave analysis presented here are in excellent agreement with theoretical and experimental resultsavailable in the open literature. Numerical results show that the effect of the superstrate layer on theresonant frequency and half-power bandwidth of the superconducting rectangular patch is stronger thanthat of the structure without superstrate layer as both the thickness and permittivity of the superstrateincrease. Finally, numerical results concerning the effects of the parameters of superstrate-substrateand superconducting patch on the antenna performance are also presented and discussed