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This paper focuses on studying and simulating a GaAs1-xPx/Si1-yGey/Ge triple-junction solar cell structure. First, the strain and the bandgap energy associated to the SiGe layer have been studied. The optimal germanium concentration is 0.88 with a strain around 0.45%. Then, the phosphor concentration effect on the strain and the bandgap energy of the upper layer GaAs1-xPx/Si0.12Ge0.88 has been optimized. At room temperature, the optimal output parameter reach Jsc=34.41mA/cm², Voc=1.27V, FF=88.42% and =38.45% for an absorber thickness of 4.5µm and x=0.47, with a strain that doesn't exceed 1.5%. This study has enabled us to design a high-efficiency, low cost 3J solar cell. [ABSTRACT FROM AUTHOR]

The parameterization of spatially distributed hydraulic properties is one of the most crucial steps in groundwater modeling. A common approach is to estimate hydraulic properties at a set of pilot points and interpolate the values at each model cell. Despite the popularity of this method, several questions remain about the optimum number and distribution of pilot points, which are determining factors for the efficiency of the method. This study proposes a strategy for optimal pilot point parameterization that minimizes the number of parameters while maximizing the assimilation of an observed dataset unevenly distributed in space. The performance of different pilot point distributions has been compared with a synthetic groundwater model, considering regular grids of pilot points with different spacings and adaptive grids with different refinement criteria. This work considered both prior and iterative refinements, with a parameter estimation step between successive refinements. The parameter estimation was conducted with the Gauss–Levenberg–Marquardt algorithm, and the strategies were ranked according to the number of model calls to reach the target objective function. The strategy leading to the best fit with the measurement dataset at the minimum computational burden is an adaptive grid of pilot points with prior refinement based on measurement density. This strategy was successfully implemented on a regional, multilayered groundwater flow model in the south-western geological basin of France. [ABSTRACT FROM AUTHOR]

Monitoring control of industrial systems is essential for the good productivity and safety of installations and operators, with better performance that must be guaranteed. This is often challenging due to the nonlinearities and dynamic complexities of these systems, adding operating constraints and instability. Hence, the multi-models constitute then an adapted tool for the modeling of the nonlinear systems to characterize their dynamic behaviors. Indeed, this work proposes the implementation of a hybrid identification approach of the operating variables of a gas turbine, thus making it possible to interconnect the various linear sub-models with decoupled states in order to generate the global output of their nonlinear model, from the exploitation in real time of the turbine's input/output data. However, the suggested decoupled-state multi-model approach offers an interesting alternative to the optimization procedure of the estimated turbine parameters. By using gradient and Gauss–Newton algorithms, improved by genetic algorithms combined with NSGA-II in hybrid form, in order to converge toward the best solutions with an optimal cost function, the obtained implementation results show that this approach allows the convergence of the estimated turbine variables and describes its behavior in real time, with the guaranteed efficiency of the proposed decoupled state multi-model method. [ABSTRACT FROM AUTHOR]

This study investigated the association of environmental factors with insect richness and nested patterns in the distribution of species of insects on small islands (northeastern Algeria). Insect species on eleven (11) islands were sampled using pitfall traps, sweep netting and a Japanese umbrella. To explain patterns in insect diversity on small islands, a generalized linear model (GLM) was used to determine the association of the overall richness and that of the dominant orders of insects with environmental variables (altitude, surface area, isolation, plant richness and number of habitats). To determine the nestedness pattern on these islands, the online interface NeD was used to measure total matrix nestedness. Of the variables measured, only plant richness was associated with variations in the overall species richness and that of the five dominant orders. The overall number of insects and that of the five dominant insect orders were significantly nested in all null models except the very restrictive FF model. Plant richness accounted for the nested structure of the overall number of insects and that of the five dominant orders (Coleoptera, Hymenoptera, Hemiptera, Diptera and Lepidoptera). Surface area was also important in the nested structure of overall number of insects and that of the order Lepidoptera. The nestedness of the overall number of insects and that of the five dominant orders of insects, however, did not result from passive sampling and selective colonization. The most effective way of conserving overall number of insects and that of the five dominant orders of insects on the Algerian islands studied is to protect their plant richness and to maximize the overall number of species and that of Lepidoptera on these islands, conservation should concentrate on the largest islands. [ABSTRACT FROM AUTHOR]

Introduction: Invasive and superficial fungal infections are increasingly reported in Algeria, testifying to the increase in their frequency in parallel with the increase in risk factors and the availability of diagnostic means, at least in university hospitals (CHU). The latter, located in the major northern cities, are equipped with high‐performance diagnostic tools compared to hospitals in the interior of the country. Methods: A comprehensive search of published and grey literature was undertaken. Prevalence and incidence of discrete fungal diseases were estimated using a deterministic modelling approach based on populations at risk. Population (2021) and major underlying disease risk groups were obtained from UNAIDS, WHO Tuberculosis and the international transplant registries as well as published data for asthma and COPD. The health service profile was summarised from national documentation. Results: Among the 43.6 million, including 12.9 million children, living in Algeria, the most prevalent fungal diseases are tinea capitis (>1.5 million), recurrent vaginal candidiasis (>500,000) and allergic fungal lung and sinus disorders (>110,000) and chronic pulmonary aspergillosis (>10,000). Life‐threatening invasive fungal infection incidence includes 774 Pneumocystis pneumonia in AIDS, 361 cryptococcal meningitis, 2272 candidaemia and 2639 invasive aspergillosis cases. Fungal keratitis probably affects >6000 eyes each year. Conclusions: Fungal infections are underestimated in Algeria because they are sought in patients with risk factors only after bacterial infections when they should be sought in parallel. The diagnosis is only accessible in hospitals in large cities and the work carried out in mycology is rarely published, making the estimation of the burden of these conditions difficult. [ABSTRACT FROM AUTHOR]

Ball mills are the foremost equipment used for grinding in the mineral processing sector. Lifters are placed on the internal walls of the mill and are designed to lift the grinding media (balls) to a higher position. In the calculation of energy consumption in ball mills, classical theories mainly consider factors like the charge fill level, lifter dimensions, the number of lifters, and the rotational speed of the mill. This research recognizes the significance of lifter geometry and proposes a new lifter design aimed at optimizing the energy consumption and efficiency of ball mills. Simulation results by discrete elements obtained in this study were validated using experimental results. By conducting this comparative analysis, the aims of the study was to examine the impact of the new lifter's geometry and rotational speed of the mill on torque, power draw, particles behavior, and contact forces. The findings indicate that when the pitch of the lifters is increased, there is a reduction of 3.30% in torque and power consumption. Additionally, this change leads to an increase in the number of cataracting particles and a 6 to 7% increase in contact forces compared to lifters with a straight shape. [ABSTRACT FROM AUTHOR]

In this work, the design and simulation of an GaInP single junction solar cell are presented. The work focuses mainly on the optimization of the PN junction thicknesses of n-base and pemitter cell layers in order to improve the cell conversion efficiency. Besides this optimization, the layers of the cell window AlGaInP and an added buffer AlGaAs were also optimized in term of doping and thicknesses using Atlas tool of SILVACO TCAD. The cell is simulated under the conditions of 1 sun and AM1.5G solar spectrum at 25°C. The simulated GaInP solar cell demonstrates an efficiency (η) of 22.42%. The cell shows different electrical behaviors in terms of short circuit current density (Jsc), open circuit voltage (V∝), fill factor (FF), and external quantum efficiency (EQE). The obtained results are compared with those reported in the literature. Simulation results of the cell are: a Jsc of 18.35 mA/cm2, V∝ of 1.41 V and FF of 86.81% with the corresponding n-base layer and pemitter layer thickness of 0.410 µm and 0.174 µm respectively and the total device thickness of 0.65 µm. According to these results, the proposed cell demonstrates an improvement in the efficiency and a reduction of the used GaInP material. [ABSTRACT FROM AUTHOR]

Summary: This effort is founded on the modeling and simulation of the GaAsPN/GaP quantum dot (QD) solar cell. This quaternary alloy is one of the III‐V semiconductors, which gained importance in the recent years for optoelectronic applications. This importance comes from the fact that the quaternary GaAsPN can be a well‐grown lattice matched to GaP and Si substrates and to the bandgap that can be decreased drastically with the incorporation of nitrogen and arsenic into GaP, improving consequently the absorption and the wavelengths near the red part. These qualities make GaAsPN a good candidate for the growth on the Si substrate and low‐cost solar cell fabrication. The optical properties of GaAsPN/GaP QDs, such as strain, critical thickness, bandgap energy, the external quantum efficiency, and absorption coefficient, have been reported. The heterostructures consist of GaAs0.18P0.814N0.006 QDs separated by GaP barrier layers. The width and thickness of QDs are about 5 and 5 nm, respectively. Our results have been shown that 20 GaAs0.18P0.814N0.006/GaP QD layers produce a short‐circuit current of about 3.55 mA/cm2 and an efficiency of about 7.5%. In addition, we will be able to extend the absorption edge of a GaP solar cell from 0.48 μm to 0.5 μm for the same QD number layers inserted. The temperature effect on efficiency is considered. [ABSTRACT FROM AUTHOR]

CeO2 and La2O3 oxides supported NiO loading (5 and 20 wt%) were synthesized, characterized by ICP‐AES, XRD, IR‐ATR, SEM, B.E.T, H2‐TPR and applied to CO oxidation with and without pretreatment under H2 atmosphere. It was shown that the support has a significant effect on the bulk, surface and reactivity properties. The reduction of nickel to metallic species occurred at higher temperatures in ceria case. 20‐Ni/La sample showed the best catalytic activity without reduction but this behavior mitigates when the sample pretreated under H2 indicating that the presence of different kinds sites responsible of CO oxidation. An opposite reactivity property was obtained in 5‐Ni/La and 20‐Ni/La cases and the interfacial γ‐type NiO interactions decreases with NiO loading which was coincident with CO oxidation activity. The active species in 20‐Ni/La sample is of type metal/support interface≡γ‐NiO/La2O3. In contrast, for 5‐Ni/La and 20‐Ni/Ce catalysts, γ‐NiO active sites incorporated into support is available. [ABSTRACT FROM AUTHOR]

In this paper, the CuInGaSe 2 based solar cell optimization has been established. We have simulated the structural strain effect. The effect of gallium concentration on the optical properties and the quantum external efficiency EQE was investigated. We also optimized the concentration x at low defect densities. The optimal gallium concentration is 0.30. We obtained an efficiency of the CuIn 0.70 Ga 0.30 Se 2 absorber solar cell around 24% with a strain ɛ = 0.64% and material defects densities equal to 1.2x1015cm−3. This work has been validated by theoretical and experimental studies. This study allows us to find a compromise between concentration x and defect concentrations in order to improve the performance and high efficiency of the solar cell. • The effect of structural deformation has been studied and simulated. • The effect of gallium on the optical properties and EQE was investigated. • We optimized the x concentration at low defect concentrations. • An efficiency of the solar cell which is equal to 24% with ɛ = 0.6% was obtained. • This work is validated by a theoretical and experimental study. [ABSTRACT FROM AUTHOR]

This study aims to investigate the different optical properties of the ZnSnN 2 absorber layer such as absorption, reflection and transmission coefficients. The effects of the ZnSnN 2 absorber layer thickness, temperature,and defect density on electrical parameters such as short circuit current density, open circuit voltage, fill factor and efficiency have also been studied in detail. These factors play an important role in the performance of the ZnO/CdS/ZnSnN 2 /Si/Mo structure. The highest efficiency of about 23.32 % is achieved without defects in the ZnSnN 2 absorber layer, under the 1-sun AM1.5 solar spectrum, by applying the flat band condition and considering the strain values of 0.37 % (ZnSnN 2 /Cds) and 7.17 % (ZnSnN 2 /Si). In addition to high efficiency, the ZnSnN 2 has a high absorption coefficient. This device will play a crucial role in optoelectronic applications. This structure is a promising candidate for low cost and high efficiency photovoltaic technology. [ABSTRACT FROM AUTHOR]

In industrial practice, the representation of the dynamics of nonlinear systems by models linking their different operating variables requires an identification procedure to characterize their behavior from experimental data. This article proposes the identification of the variables of a two-shafts gas turbine based on a decoupled multi-model approach with genetic algorithm. Hence the multi-model is determined in the form of a weighted combination of the decoupled linear local state space sub-models, with optimization of an objective cost function in different modes of operation of this machine. This makes it possible to have robust and reliable models using input / output data collected on the examined system, limiting the influence of errors and identification noises. [ABSTRACT FROM AUTHOR]

Mutations in the gene encoding surfactant protein C (SP‐C) cause interstitial lung disease (ILD), and glucocorticosteroid (GC) treatment is the most recognized therapy in children. We aimed to decipher the mechanisms behind successful GC treatment in twins carrying a BRICHOS c.566G > A (p.Cys189Tyr) mutation in the SP‐C gene (SFTPC). Methods: The twins underwent bronchoscopy before and after GC treatment and immunoblotting analysis of SP‐C proprotein (proSP‐C) and SP‐C mature in bronchoalveolar fluid (BALF). Total RNA was extracted and analysed using quantitative real‐time PCR assays. In A549 cells, the processing of mutated protein C189Y was studied by immunofluorescence and immunoblotting after heterologous expression of eukaryotic vectors containing wild type or C189Y mutant cDNA. Results: Before treatment, BALF analysis identified an alteration of the proSP‐C maturation process. Functional study of C189Y mutation in alveolar A549 cells showed that pro‐SP‐CC189Y was retained within the endoplasmic reticulum together with ABCA3. After 5 months of GC treatment with clinical benefit, the BALF analysis showed an improvement of proSP‐C processing. SFTPC mRNA analysis in twins revealed a decrease in the expression of total SFTPC mRNA and a change in its splicing, leading to the expression of a second shorter proSP‐C isoform. In A549 cells, the processing and the stability of this shorter wild‐type proSP‐C isoform was similar to that of the longer isoform, but the half‐life of the mutated shorter isoform was decreased. These results suggest a direct effect of GC on proSP‐C metabolism through reducing the SFTPC mRNA level and favouring the expression of a less stable protein isoform. [ABSTRACT FROM AUTHOR]

• We report the modelling and optimization of a solar cell based on new material using SCAPS software. • A high absorption coefficient was found. • The influence of thickness, temperature, resistances and defects on the different electrical parameters. • A high conversion efficiency was obtained under optimum parameters. • A respectable compatibility has been shown compared with the results of wxAMPS software. Based on several semiconductor research, we have studied one of the new semiconductors, due to its exciting physical proprieties that in turn solve some problems in the photovoltaic's industry. We have divided this work into two parts. The first part, is to study the optical proprieties of ZnSnN 2 , as calculation of the absorption coefficient, bandgap, reflection coefficient, and transmission coefficient. As for the second part, a study of some parameters that affect the efficiency of p-CuCrO 2 (CCO)/ n-ZnSnN 2 (ZTN) solar cell using SCAPS-1D software, and our results are compared with the results of another software (wxAMPS), where results showed great compatibility with the presence of weak uncertainty. We have studied the influence of many parameters such as the thickness of the absorber layer (n-ZnSnN 2), the thickness of the buffer layer (p-CuCrO 2) , the temperature, the series resistance (R s), the shunt resistance (R sh) and the defect density on the performance of ZnSnN 2 solar cells which included in the real device. The photovoltaic parameters have been calculated using AM1.5G solar irradiance at the intensity of one sun, a temperature of 300 K, and considering the flat band condition at the interface. We have been achieving a high-efficiency of η ≈ 22% without defects. Given the characteristics of this new semiconductor ZnSnN 2 , which composed of earth-abundant, non-toxic and inexpensive element, as well as a high absorption coefficient, it can be considered as an alternative for PV and optoelectronic applications. [ABSTRACT FROM AUTHOR]

The relationship between the abundance of breeding birds on the studied islands and the topographic variables (surface and distance from the continent) was tested via data on the breeding birds of 11 islands in Algeria. A nestedness calculator program was used to study the nestedness of breeding birds. Islands' surface conditions and their isolation explain clearly the richness of breeding birds. The distribution of island breeding birds showed a strong nested structure that differs significantly from the distribution of the random model. [ABSTRACT FROM AUTHOR]

Background: Congenital hemolytic anemia constitutes a heterogeneous group of rare genetic disorders of red blood cells. Diagnosis is based on clinical data, family history and phenotypic testing, genetic analyses being usually performed as a late step. In this study, we explored 40 patients with congenital hemolytic anemia by whole exome sequencing: 20 patients with hereditary spherocytosis and 20 patients with unexplained hemolysis.Results: A probable genetic cause of disease was identified in 82.5% of the patients (33/40): 100% of those with suspected hereditary spherocytosis (20/20) and 65% of those with unexplained hemolysis (13/20). We found that several patients carried genetic variations in more than one gene (3/20 in the hereditary spherocytosis group, 6/13 fully elucidated patients in the unexplained hemolysis group), giving a more accurate picture of the genetic complexity of congenital hemolytic anemia. In addition, whole exome sequencing allowed us to identify genetic variants in non-congenital hemolytic anemia genes that explained part of the phenotype in 3 patients.Conclusion: The rapid development of next generation sequencing has rendered the genetic study of these diseases much easier and cheaper. Whole exome sequencing in congenital hemolytic anemia could provide a more precise and quicker diagnosis, improve patients' healthcare and probably has to be democratized notably for complex cases. [ABSTRACT FROM AUTHOR]

The experiment was conducted at the level of a pilot farm located in eastern Algeria under a humid bioclimatic stage, during two successive crop years. The study focused on a F1 generation of barley (Hordeum vulgare L.) consisting of twelve hybrids from a complete diallel cross between the two locals varieties (Saida and Tichedrett) and two other introduced varieties (Nadawa and Fouara). The aim was to determine the value of parental genotypes as genitors and to analyze their descendants, while evaluating the phenotypic variability of ten quantitative variables. Analysis of the variance revealed a significant difference for the whole of parameters studied in the parents as in their descendants. Additive and non-additive effects are involved in the genetic control of the analyzed variables. The Hayman model (1954) seems acceptable for five variables on ten variables studied for which additive effects are more important than dominance effects. The analysis of the heterosis effect was significant for the characters tested. For the productivity of the plant, eight hybrids on twelve have expressed a positive heterosis compared to the mid- parent, six combinations on twelve have registered a positive heterosis compared to the over-batter parent and compared to the best variety with an overall heterosis of 17.53%. [ABSTRACT FROM AUTHOR]

This work presents electrical simulations and the optimization of the device structure ITO/PEDOT:PSS/PTB7:PC70BM/Al, using OghmaNano (Organic and hybrid Material Nano) software. The result analysis was given at different layer thickness and the best performance characteristics are obtained at 250 nm of the active layer. Then, the simulated results of different parameters such as charge carrier mobility, temperature and series resistance are investigated. Different structures of organic solar cells, the role of the interface layer used as a hole transport layer and the effect of electrodes are discussed. Finally, the energy level of the device is explained by the optical simulation and the optimized solar cell was proposed. [ABSTRACT FROM AUTHOR]

A combination of a Copper Indium Gallium Selenide (CIGS) and Silicon (Si) layer has been recognized as an excellent choice for producing heterojunction based solar cells with improved efficiency and low cost processing techniques. The quaternary compound CIGS and silicon (Si) regions exhibit a lattice mismatch of about 5%, which induces a strain and impacts the electronic characteristics of the CIGS/Si heterojunction solar cell. A new viewpoint suggests the integration of a silicon germanium (Si 1-y Ge y) layer in the CIGS/Si region to reduce the impact of lattice mismatch. The objective of this study is to investigate how different gallium and germanium concentrations (x Ga and y Ge) affect the following factors: lattice mismatch (ε) , critical thickness (h c) and absorption coefficient (α)of CIGS/SiGe based solar cells. It also aims to analyze how these concentrations impact the primary parameters used to evaluate solar cell performance such as external quantum efficiency, short circuit current density, fill factor, open circuit voltage and conversion efficiency. The simulation results agree well with the existing theoretical and experimental literature data, confirming the suitability of the physical characteristics employed in this numerical study. By tuning the concentrations of Gallium and Germanium, it is feasible to attain an efficiency of 24% owing to the lattice compensation phenomenon in Si 1-y Ge y layers. These findings hold significant implications for the development and advancement of solar cell technology, as well as for enhancing their conversion efficiency and commercialization. • A strain-compensated CIGS/Si structure was achieved by adding SiGe layer. • The incorporation of SiGe improves the absorbance and EQE of the CIGS solar cell. • The improvement of the solar performances of the CIGS is ensured by the SiGe layer. • Optimizing Ga, Ge concentrations makes it possible to achieve an efficiency of 24%. [ABSTRACT FROM AUTHOR]

Abstract An Ultra-Thin-Body (UTB) InP/InAs/InGaAs MOSFETs is investigated. Computer Aided Design(CAD) tools are used to extract the electrical properties of this structure.Our simulation work gives us the possibility to extract the output characteristics, transfer characteristics and RF performances. With the small-signal equivalent circuit models, intrinsic elements are calculated from the Y-parameters matrix using AC analysis. To further improve the accuracy of the simulation, the effect of doping in the channel and source-drain regions, the Indium content in different layers are discussed and optimized. The results are validated with device characteristics of the fabricated 150 nm InP/InAs/InGaAs MOSFET. A high drain current of 665 mA/mm and extrinsic peak transconductance of 440 mS/mm are obtained at V ds = 0.7 V. A current gain cutoff frequency f T of 41.69 GHz and a simultaneous maximum oscillation frequency f max of 94 GHz are estimated at V ds = 0.7 V and V gs = 0.2 V. [ABSTRACT FROM AUTHOR]

Abstract In this work, we theoretically investigate the structural dependence of intersubband absorption of InGaAsSb/GaAs single quantum well structures. We begin by analyzing the impact of In and Sb incorporation on the critical thickness, conduction band offset and band gap energy. The first two electron energy levels E 12 and the corresponding wavelength were made for the In x Ga 1− x As 1- y Sb y /GaAs system and are analyzed in detail by solving the Schrödinger equation. Also, we have investigated effects of composition and well width on the intersubband absorption. In addition, the wavelength and absorption coefficient of the ISBT can be adjusted and optimized by changing the composition and the width of the SQW. Finally, strain effects on intersubband absorption and on the peak response wavelength have also been systematically studied. Our study shows that InGaAsSb/GaAs SQW will play a key role in research of electronics and photonic devices in the future. Highlights • Studied the effects of structural parameters on the Intersubband transition of InGaAsSb/GaAs QWs. • Absorption coefficient dependency on the InGaAsSb structural parameters has been investigated. • The effects of these parameters are numerically studied. • Effect of the strain on peak wavelength and on the maximum absorption has been verified. • InGaAsSb/GaAs is a good candidate as a novel material system for optoelectronic intersubband devices. [ABSTRACT FROM AUTHOR]

Abstract This work investigates the influence of the ion source (Au+ and Si+2 ions) of liquid metal alloy source-focused ion beam (LMAIS/FIB) on the nanopattering. Two sets of SiO 2 /Si nanopatterns with a width of 450 nm on Silicon on insulator (SOI) substrate are fabricated by 30 keV Au+ and Si+2 ions, respectively. To study this effect, the sputtering yield is calculated using the volume loss method from atomic force microscopy (AFM) profiles obtained for each set. The results of the sputtering yield were compared with theoretical results calculated from Yamamura model for normal incidence for validation. The comparison showed a good agreement between the two results with a relative difference of about 5.3% obtained using Si+2 ions. Highlights • The effect of AuSi LMAIS/FIB ions on nanomilling is investigated experimentally. • This effect has been shown through the study of sputtering yield. • The comparison has shown that Au+ ions are better for stable nanopatterns. • Our experimental results are in good agreement with calculated results. [ABSTRACT FROM AUTHOR]

The aim of this modeling and simulation is to study the influence of the incorporation of nitrogen (N) and aluminum (Al) on the optoelectronic properties of the structure Al x Ga 1-x As 1-y N y /Ge, and then choose the right combination (N, Al) which gives us a better conversational efficiency of the junction(Al x Ga 1-x As 1-y N y /Ge), in this study, we simulated the effect of N and Al on the strain, the band gap, carrier mobility and structure efficiency where we based on theoretical models experimentally validate, It has been shown that the Al concentration slightly affects the stress and the band gap, but it has a significant influence on the incorporation of nitrogen and in a more homogeneous way introducing a dramatic decrease in the band gap what change considerably the absorption, carrier mobility and final yield of the structure. [ABSTRACT FROM AUTHOR]

In this work we report a modeling and optimization of a novel core (p-GaN)-multishell (i-In x Ga 1-x N/i-GaN/n-Al 0.1 Ga 0.9 N/n-GaN) coaxial NWs with a total length of about 3 μm and a radius of 0.19 μm. The variation of Indium composition in the i-In x Ga 1-x N active layer shows that x = 15% is the optimal composition that gives a good short circuit current and efficiency of about 2.24 mA/cm 2 and 2.93%, respectively. Beyond x = 35% the structure starts to present deteriorations. Moreover, the optimal x composition founded provides a gain of about 12.9% of EQE in the mid-infrared part. The study of the variation of the total current density along the nanowire demonstrates that the maximum of this latter is located in AlGaN cladding shell layer and at the interfaces between the i-region and AlGaN cladding shell layer. In other hand, our results show that our structure presents an optimal efficiency of about 3.5% at a temperature of 275 K with the same AM1.5G solar spectrum. [ABSTRACT FROM AUTHOR]

This paper reports simulations of gradual bandgap CIGS absorber and its impact on the characteristics of a solar cell. The bandgap of the CIGS absorber varies linearly and drops from E gmax (at the junction limit) to E gmin (in the vicinity of the rear contact).We introduce an effective absorption coefficient based on this variation. We will demonstrate that this gradual profile contributes to an improvement up to 171 mV of the open circuit voltage V oc of the cell that is linked to the modification of the internal electrical field distribution within the absorber. However, a joint reduction of 1.50 mA/cm 2 of short circuit current density, J sc , is observed. Overall, the conversion efficiency increases from 19.2%, for a uniform bandgap absorber structure, to 24.9% in that case of gradual bandgap. Additionally, we investigate the impact of absorber thickness and temperature on cell characteristics. [ABSTRACT FROM AUTHOR]

In this present work, the aim is to evaluate the effect of different times of ultrasound pretreatment prior to hydrodistillation (US-HD) on the yield, chemical composition and antioxidant activity of essential oils of two wild Lavandula stoechas L. from the North of Algeria. The results indicate that ultrasound treatment engenders a rapid release of essential oils (1.59 %) recovery after only 10 min of sample of Adekar treated by ultrasound and followed by 90 min of hydrodistillation (HD) versus 180 min of hydrodistillation of untreated sample (1.17 %). However, the yields of Keddara sample treated by 45 min versus untreated samples were 0.87 % versus 0.62 %. 94.30 % and 88.26 % of total compounds were identified using chromatographymass spectrometry (GC-MS) in samples of Adekar and Keddara treated by ultrasound versus untreated samples (92.64 % and 88.75 % respectively). A difference in chemical composition between the essential oils of the two harvesting sites and between the extracts obtained by HD and by US-HD was found. The percentage of the most of the major compounds (fenchone, camphor, 1,8-cineole, bornyl-acetate, myrtenyl-acetate and viridiflorol) and other compounds identified is higher in treated L. stoechas L. than untreated L. stoechas L. The study of antioxidant power was carried out by 2, 2 diphenyl-1-picrylhydrazyl (DPPH) method. The results showed that antioxidant power of treated samples is superior to antioxidant power of untreated samples. Antioxidant activity of both samples (treated and untreated) is less effective compared with antioxidant activity of ascorbic acid. [ABSTRACT FROM AUTHOR]

In this work we propose a modeling and simulation of core/shell p-i-n Si/Si 0.2 Ge 0.8 nanowire for photovoltaic. In the first step of this work, we have compared the core/shell p-i-n homojunction Si and heterojunction Si/Si 0.2 Ge 0.8 Nanowire (NW) solar cell having a length of 3 μm and a radius of 0.19 μm, by studying their current-voltage and external quantum efficiency (EQE). Our results have shown that blending Silicon with 80% of Germanium enhances relatively the short circuit current and efficiency by 3.04% and 8.48% respectively. In other hand, the absorption edge of Silicon NW has extended from 1100 nm to 1200 nm, with a gain of EQE of 15% obtained in this range. In the second part, we have tried to optimize the Si/Si 0.2 Ge 0.8 structure, by varying their radius and length. The corresponding results have indicated that a radius of 0.28 μm and a length of 10 μm are the optimal geometric parameters for any optimization of such structure. [ABSTRACT FROM AUTHOR]

In this study, the perovskite-type oxides Ba0.5Sr0.5Ni0.2Co0.6Fe0.2O3-δ (BSNCF) with different B-site transition metal elements were investigated as a new catalyst for methanol oxidation. They were prepared by the partial substitution of cobalt by nickel in Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF) sample. Both materials prepared using a combined citrate/EDTA complexing method and their catalytic activitiesfor methanol oxidation were comparativelystudied using cyclic-voltammetry (CV) and chronoamperometry (CA) in alkaline media at room temperature. Structural, textural, morphological and redox properties of the synthesized solids were investigated by several physicochemical methods such as XRD, FTIR, LRS, SEM-EDX, BET and H2-TPR. The as-prepared materials were obtained with high purity and high crystallinity. The partial substitution of cobalt by nickel in BSCF perovskite changes the structure of the solid which pass from cubic structure to a mixture of cubic and hexagonal forms. This change is accompanied by an increase in BET surface area and a decrease in crystalline size. For the electro-catalysis measurements, results demonstrated that partially substituting of Co by Ni in BSCF structure enhance the electro-catalytical activity towards the oxidation of methanol under alkaline conditions, making it an electro-catalyst candidate for practical utilization in DMFCs. [ABSTRACT FROM AUTHOR]

The effect quenching and tempering by different regimes on Rockwell hardness and wear processes of grinding balls 50 and 70 mm in diameter made of two melts of chromium-molybdenum cast iron is studied. The heating temperature for quenching is 850, 950, and 1050°C; the tempering temperature is 250, 400, and 600°C. Iron is analyzed in an electron microscope. Diffraction patterns are obtained. A model of cast iron wear is suggested and compared to the Davis model and to experimental results. An optimum heat treatment regime is proposed. [ABSTRACT FROM AUTHOR]

The present study reports the impact of structural parameters on optoelectronic properties of InGasb/GaSb based quantum well structures (Qws). The laser diodes are designed to operate at 2.3 μm at 300 K. Numerical calculations of the emission wavelength, optical and modal gain of TE mode in InGaSb/GaSb laser diode structure have been carried out for various well material compositions, well thickness, number of quantum wells and temperature. The optical confinement factor and threshold current density are also simulated and reported. The calculations were performed using the 8-bands k.p model. For an injected carrier concentration of 1.56 × 1018 cm−3 at 300 K, peak gain value of the order of 1400 cm−1 is reached and a modal gain of 94 cm−1 can be obtained. A threshold current density around 3 kA/cm2, is expected to be obtained through optical losses of about 50 cm−1. The results show that InGaSb/GaSb quantum wells are appropriate for mid-infrared lasers operating at 300 K. • Type-I InGaSb/GaSb lasers, emitting at 2.3 μm are studied. • Optical/modal gain, confinement factor and the threshold current density are investigated. • A modal gain of 94 cm−1 can be reached at room temperature. • J th of 3 kA/cm2 is obtained under optical losses of about 50 cm−1 and T 0 =57 K at RT. • InGaSb/GaSb QWs are appropriate for mid-infrared lasers operating at T=300 K. [ABSTRACT FROM AUTHOR]

This paper focuses on the simulation and optimization of electrical and optical properties such as current density-voltage (J-V ) , external quantum efficiency (EQE) and the photoluminescence spectra (PL) of InSb/GaAs quantum dot solar cell (QDSC). The InSb QDs have been inserted in the intrinsic region of p-i-n GaAs solar cell. Our results have been shown that 30 InSb/GaAs QD layers provide a relative enhancement of 22.35% and 29.30% of the short-circuit current and the efficiency, respectively. With the same number of the QD layers, the absorption range edge of low energy photons has been extended from 900 to 1400 nm. The electrical features obtained for InSb/GaAs QDSC have been compared with those obtained for InAs/GaAs QDSC in goal to show the better structure. The PL spectra has been also compared with experimental result for the same structure. Moreover, the QDSC has been optimized with respect to the thickness of QDs. The optimal conversion efficiency of 10 QD layers is improved from 14.85% to 18.30% by increasing the thickness of the QDs from 5 nm to 20 nm. [ABSTRACT FROM AUTHOR]

The electrical properties of InAsP/Si quantum dot solar cell (QDSC) are numerically studied and analyzed in this paper. Many effects like number of quantum dot (QD) layers inserted and Arsenic content of InAs x P 1-x on photovoltaic properties such as current density-voltage J-V and the external quantum efficiency (EQE) are investigated. Our results have been shown that the optimal Arsenic content is 0.6. With 30 InAsP/Si QDs layers, relative enhancements of about 7% and 6.70% of short-circuit current and efficiency are achieved, respectively. Otherwise, the absorption range edge of low energy photons was extended from 1120 to 1200 nm. This reveals that introduction of QDs in the intrinsic region of p -i- n Silicon (Si) solar cell enhances significantly the device characteristics beyond what has been reported for conventional semiconductor-based solar cells. [ABSTRACT FROM AUTHOR]

In this work, the performance of solar cell based on CdS-n/Cu 2 ZnSnS 4 -p hetero-junction is numerically simulated. The aim of the study is to investigate the influence of thickness, defects density and bandgap energy of absorber layer CZTS and the thickness of the buffer layer CdS of the solar cell on electrical parameters J sc , V oc , FF and efficiency η of the cell. The results of our simulation allowed us to optimize the parameters above mentioned in order to get the best efficiency at the optimal band gap which corresponds to the maximum of the solar spectrum with optimal values of the electrical performances of the cell. This results lead to develop CZTS solar cells with high efficiency and low cost and give a help full indication for fabrication process. [ABSTRACT FROM AUTHOR]

In recent years, the development of quantum well solar cells QWSCs (Quantum Well Solar Cells) has generated a great deal of interest. These configurations have shown good promise to optimize the low conversion efficiency of conventional solar cells because of the high rate of absorption losses present in them. In this work, we are interested in modeling and simulation of two different structures of solar cells, a simple solar cell based on silicon Si and a quantum well solar cell SiGe/Si. When a solar cell is compared to 80 quantum well layers of Si 0.8 Ge 0.2 with a pin solar cell based on Si. The short circuit current J sc increases from 23.55 to 37.48 mA/cm 2 with a relative increase of 59.15% found. In addition, the limit of the absorption band of the lower energy photons extends from 1100 nm to 2000 nm. [ABSTRACT FROM AUTHOR]

The number of decentralized photovoltaic (PV) systems generating electricity has increased significantly, and its monitoring and maintenance has become a challenge in terms of stability, reliability, security, efficiency, as well as energy production costs. Hence, prevention against faults and breakdowns becomes essential. In this work, a Convolutional Neural Network (CNN) model and a fine-tuned model based on Visual Geometry Group (VGG-16) have been examined to address the issue of fault diagnosis of PV modules using thermographic images. For fault detection, we have used binary classification, and multiclass classification for identification the type of fault. The database used in this study was made up of an imbalanced class distribution of infrared thermographic images of PV modules under normal and faulty conditions (such as bypass diode failure, partially covered PV module, shading effect, short-circuit and dust deposit on the PV surface). The test facility is located at the Unit for Developing Solar Equipment's (UDES), in the north of Algeria. The average accuracy archived using the fine-tuned VGG-16 model is 99.91% for the fault detection and 99.80% for the fault diagnosis of five types of defects. Experimental tests show high accurate prediction results using the fine-tuned model and somewhat less accuracy using the small Deep Convolutional Neural Network (small-DCNN) model. • An IRTI-based approach for photovoltaic module faults detection and classification is proposed. • The detection and diagnosis models have been successfully tested using experimental data. • The fine-tuned model VGG-16 showed high accuracy compared to the small-DCNN model. [ABSTRACT FROM AUTHOR]

In this aim, we were interested in the optimization and simulation of pin-In 1−x Ga x N structure and InGaN multi quantum well structures for photovoltaic applications. This ternary alloy which is an III–V semiconductor presents important characteristics especially its gap energy, thus, the increase of the photons absorption of wavelengths. It has been shown that the increase in indium concentration increases the current density J sc and the maximum output power. In return, the V oc decreases consequently. For In 0.50 Ga 0.50 N structure we observed that the current density and the maximum power are respectively around 19.50 mA/cm 2 and 27.50 mW/cm 2 with a ratio of 21.65 mA/cm 2 . Also it is shown that the incorporation of the quantum well in the active region results in an increase of J sc and P max but V oc remains unchanged. The incorporation of 50 quantum well structure in the In 0.50 Ga 0.50 N gives 22 mA/cm 2 of the current density and 32 mW/cm 2 of the maximum output power. The use of the structure based on In 0.50 Ga 0.50 N (MQW) induces an efficiency of 32%. We deduced that the relative efficiency is improved by 10.9%. [ABSTRACT FROM AUTHOR]

This work deals with the modeling and optimization of the CuInGaSe/CdS based structure for photovoltaic applications. We took into consideration the effect of the gallium concentration and the temperature on the strain, band gap energy, absorption and efficiency of the structure. It has been demonstrated that increasing the gallium concentration increases the ban gap energy, while increasing temperature decreases it. These two parameters vary the efficiency significantly. For x = 30% and T = 300 K, the band gap energy is equal to 1.15 eV with a deformation of 0.5% and efficiency around 20%. We have also found that at this value of the band gap energy the structure absorbs most of the incident photons. Then to achieve a reliable cell based on CuInGaSe/CdS it is adequate to find a compromise between the gallium concentration in the alloy, the temperature and the strain. [ABSTRACT FROM AUTHOR]

In this work we develop the idea of using a poly methyl methacrylate (PMMA) polymer doped with optically active molecules such as photovoltaic encapsulation materials. The effect of this encapsulation system on the incident solar spectrum has been obtained from direct allowed transition after the samples have been exposed to sunlight. A resulting, the incident solar spectrum at the interface is red-shifted for a better fit with the spectral response of SiO 2 /Si solar cell structures. The simulation results showed that the short-circuit current density increased by 7%. Therefore the mechanism of the photo-degrading by UV illumination of an LDS has been studied to identify molecular changes that occur in the organic dye when exposed to UV light. The photo-degrading effect of the PMMA layer was measured by CONICA-MINOLTA spectrometer, as a function of increasing exposure time to UV light. The UV Photo-degrading studies revealed that the more photo-stable dye doped in value. [ABSTRACT FROM AUTHOR]

The all-electron full-potential linearized augmented plane-wave method is used to show that the variation of tetragonality of the L1 0 MnPt antiferromagnet switches the magnetization from an easy axis to an easy plane. The optimum lattice parameters are obtained and the changing from inplane to out-of plane is explained by a competition between the strong spin orbit coupling and weak magnetization of Pt with the large magnetization and weak spin–orbit coupling of Mn. Finally we present the X-ray magnetic linear dichroism used to investigate the magnetic anisotropy of the antiferromagnet MnPt. • Structure, structural stability, dynamical properties and the phonon spectra of L10 MnPt. • Orbital and spin projected band structure and magnetic properties of Antiferromagnet MnPt. • Magnetocrystalline anisotropy as a competition between Mn and Pt atomic contribution. • Magnetocrystalline anisotropy can be tuned by strain. • XMLD as tool to investigate magnetism in L10 ordered antiferromagnetic MnPt. [ABSTRACT FROM AUTHOR]

During spring and summer (April to July) of 2009, insects of three islets in the North-East of Algeria were sampled by pitfall traps, sweep net and Japanese umbrella. Analysis of insect diversity shows the existence of 144 species in the three islets. Petit Cavallo island is the most rich with 140 species, followed by Grand Cavallo island and Grand Cavallo islet with 92 and 25 species, respectively. Diversified orders were Coleopters on the two main islet (Petit Cavallo island: 42 species, Grand Cavallo Island: 33 species) and Hymenopters on Grand Cavallo islet (10 species). For abundance, Hymenoptera was the most dominant on the three islands (Petit Cavallo: 428 individuals, Grand Cavallo island: 229 individuals, and Grand Cavallo islet: 118 individuals). The main three richer families in Petit Cavallo island were Formicidae (9 species), Pentatomidae (8 species) and Miridae (7 species). In Grand Cavallo island, two families were prosperous: Formicidae (8 species) and Chrysomelidae (6 species). However, Formicidae seemed to be richer in Grand Cavallo islet with 5 species. In terms of abundance, Formicidae was the most dominate in three islands (Grand Cavallo islet: 69.87%, Petit Cavallo island: 34.95%, Grand Cavallo isalnd: 25.88%). From the point of view of the similarity, the composition of insect fauna seemed to be close between Petit Cavallo island and Grand Cavallo island (77.58%). [ABSTRACT FROM AUTHOR]

This paper proposes a method of modeling and simulation of InAs/GaAs-based quantum dots (QDs) for solar cell. The main objective is to find the growth parameters in order to produce an optimal double heterostructure using two semiconductor materials InAs and GaAs. We are interested in particular on the impact of the growth control parameters on the physical properties of the two-dimensional InAs mono-layer. We report here a complete but non-exhaustive analysis of the electronic states of the InAs based QDs layers grown on a GaAs substrate. In this work, the reader will find the modeling and the simulation results for both rectangular and elliptical geometries of InAs QDs. In the first part of this work, we provided the change of the electronic transition energy as a function of quantum dots’ radius whilst the second one concerns the absorption coefficient as a function of the incident photon wavelength. The curves we have obtained indicate clearly that the geometrical shape of the InAs QDs does significantly modify the various parameters above. We could therefore confirm that the more appropriate geometry is the elliptical one because of the higher performances. [ABSTRACT FROM AUTHOR]

This work focuses on the modeling and optimization of a structure based on InGaP/InGaAs/InGaAsN/Ge for photovoltaic. In this study we took into consideration the concentration effect of alloys x (In) and y (N) on the strain, the bandgap, the absorption and structure efficiency. It has been shown that the concentration of indium varies the strain and the bandgap. These two parameters change considerably the yield. Also it optimized the effect of alloys on the total absorption of the structure. For a concentration of indium x = 0.40 and y = 0.03 we had a absorption coefficient which is equal to 2 × 10 6 cm −1 . We have found 50% efficiency for the multi-junction structure based on In 0.55 Ga 0.45 P/In 0.40 Ga 0.60 As/In 0.30 Ga 0.70 As 0.97 N 0.03 /Ge. To achieve a reliable high efficiency multi-junction structure, we just need to optimize the concentrations of different alloys. [ABSTRACT FROM AUTHOR]

This paper deals with theoretical investigation of the performance of current-matched InGaN/Si double-junction solar cells. Calculations were performed under 1-sun AM1.5 using the one diode ideal model. Impact of minor carrier lifetime and surface recombination velocity in the top sub-cell on the cell performances is analyzed. Optimum composition of the top sub-cell has been identified ( x = 51.8 % and E = 1.68 eV). The simulation results predict, for the optimized InGaN/Si double-junction solar cell, a short-circuit current J = 20 mA/cm, an open-circuit voltage V = 1.97 V, and a conversion efficiency η = 38.3%. [ABSTRACT FROM AUTHOR]

This paper deals with theoretical investigation of the performance of current and lattice matched GaN x As y P 1−x−y /Si double-junction solar cells. The nitrogen and arsenic concentrations ensuring lattice matching to Si are determined. The band gap of GaNAsP is calculated using the band anti-crossing model. Calculations were performed under 1-sun AM1.5 using the one diode ideal model. Impact of minor carrier lifetime and surface recombination in the top sub-cell on the cell performances is analyzed. Optimum compositions of the top sub-cell have been identified (x = 4.5%, y = 11.5% and E g = 1.68 eV). The simulation results predict, for the optimized GaNAsP/Si double-junction solar cell, a short circuit current J sc = 20 mA/cm 2 , an open circuit voltage V oc = 1.95 V, and a conversion efficiency η = 37.5%. [ABSTRACT FROM AUTHOR]

In this paper we present a geo-numerical approach for classifying fixed points of the set of ordinary differential equations (ODEs) that represent the reduced model of the cubic-quintic complex Ginzburg–Landau equation (CQ CGL) in a two parameter plane. We will solve the set of ODEs representing the system using the Dormand–Prince method (DOPRI) then by analyzing the final stage of the solution a decision will be made which will result in the classification of solutions into three categories, fixed points, limit cycles or a completely instable solutions, this approach will reveal the variety of solutions and there bifurcation from stable to oscillatory to instable solutions. This study allows us to increase the reliability of the propagation and communication in fiber optic applications. [ABSTRACT FROM AUTHOR]

In this work, we designed a two-dimensional BDJ model and used finite element method to compute the response photocurrent instead of analytic model used in previous studies. To take into consideration multiphysics aspects COMSOL is used to study the optical and electrical behaviour of a Buried Double Junction (BDJ) photodetector designed with CMOS technology, the optical study describes the propagation of electromagnetic waves through air, silicon dioxide and silicon layers, the semiconductor study gives us the photocurrent for the two buried junctions to an incident wavelength. [ABSTRACT FROM AUTHOR]