95 research outputs found

    A Generalized Discrete Event System (G-DEVS) Flattened Simulation Structure: Application to High-Level Architecture (HLA) Compliant Simulation of Workflow

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    International audienceThe objective of the paper is to specify a new flattened Generalized Discrete Event System simulation engine structure and the Workflow modeling and simulation environment embedding it. We express first the new flattened simulation structure and give the corresponding transformation functions. We analyze performance tests conducted on this new simulation structure to measure its efficiency. Then, having selected the essential concepts in the elaboration of the Workflow, we present a language of description to define the Workflow processes. Finally, we define a distributed Workflow Reference Model that interfaces components of the Workflow with respect to the High-Level Architecture standard. Today enterprises can take advantage of this platform in the context of networking where interoperability, flexibility, and efficiency are challenging concepts

    Pulse Electrodepositin of ZnO for Thin Absorber Solar Cells

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    AbstractThis study reports the influence of the condition parameters on the electrodeposition of zinc oxide using Zn(NO3)2 6H2O. ZnO thin films were electrodeposited on FTO and Mo substrate, using a pulse electrodeposition technique. Thin and adherent films have been obtained after 360 cycles. The pulse electrodeposition process was investigated though voltammetry cyclic. The morphology as well as the optical properties of the films was studied by using scanning electron microscope (SEM) and optical transmittance spectroscopy

    NUMERICAL SIMULATION OF PHOTOCURRENT IN A SOLAR CELL BASED AMORPHOUS SILICON

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    We propose in this work, a method of simulation based on the resolution of the equations of continuities for homostructures of silicon-based solar, and used a method of calculation the photocurrent delivered by the silicon solar cell applying the equations of continuities and the currents by analogy to the phenomena of loads transport according to the model of an homojunction n-a-Si:H/p-a-Si:H. We used Matlab software to simulate and optimize the layers thicknesses to achieve the maximum photocurrent generated under AM1.5 solar spectrum. The optimization of donor layer thickness shows clearly that the best results are obtained with the finest structures.  We worked out a numerical model based on the resolution of the equations of continuities who gave the results in good agreement with literature and which allowed, moreover a better control of the performances of the cells based on silicon, for their improvement

    Isolation, synthesis and optimization of cyclopropanation process of 4-allyl-2-methoxyphenol

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    The synthesis of 4-((2,2-dichlorocyclopropyl)methyl)-2-methoxyphenol 2 have been accomplished by using cyclopropanation process and Reponse Surface Methodology [1,2]. This methodology was used to determine the optimal conditions for the cyclopropanation reaction of eugenol 1. The reaction time (X1) and the ratio of the reaction mixture’s solvent (X2) were the two investigated factors. The statistical analysis of this study indicates that both of these factors had significant effects on the cyclopropanation yield. The central composite design showed that polynomial regression models were in good agreement with the experimental results of the coefficient determination (0.95) of product 2 yield. The optimal conditions were 17.44 and 5.78 hours. In such condition, the predicted yield of the product 2 was 43.96%. Keywords: Eugenol; 4-((2,2-dichlorocyclopropyl)methyl)-2-methoxyphenol; Central composite design; Optimization experiment

    Ataxia with oculomotor apraxia type 2: clinical, biological and genotype/phenotype correlation study of a cohort of 90 patients

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    Ataxia with oculomotor apraxia type 2 (AOA2) is an autosomal recessive disease due to mutations in the senataxin gene, causing progressive cerebellar ataxia with peripheral neuropathy, cerebellar atrophy, occasional oculomotor apraxia and elevated alpha-feto-protein (AFP) serum level. We compiled a series of 67 previously reported and 58 novel ataxic patients who underwent senataxin gene sequencing because of suspected AOA2. An AOA2 diagnosis was established for 90 patients, originating from 15 countries worldwide, and 25 new senataxin gene mutations were found. In patients with AOA2, median AFP serum level was 31.0 mu g/l at diagnosis, which was higher than the median AFP level of AOA2 negative patients: 13.8 mu g/l, P = 0.0004; itself higher than the normal level (3.4 mu g/l, range from 0.5 to 17.2 mu g/l) because elevated AFP was one of the possible selection criteria. Polyneuropathy was found in 97.5% of AOA2 patients, cerebellar atrophy in 96%, occasional oculomotor apraxia in 51%, pyramidal signs in 20.5%, head tremor in 14%, dystonia in 13.5%, strabismus in 12.3% and chorea in 9.5%. No patient was lacking both peripheral neuropathy and cerebellar atrophy. The age at onset and presence of occasional oculomotor apraxia were negatively correlated to the progression rate of the disease (P = 0.03 and P = 0.009, respectively), whereas strabismus was positively correlated to the progression rate (P = 0.03). An increased AFP level as well as cerebellar atrophy seem to be stable in the course of the disease and to occur mostly at or before the onset of the disease. One of the two patients with a normal AFP level at diagnosis had high AFP levels 4 years later, while the other had borderline levels. The probability of missing AOA2 diagnosis, in case of sequencing senataxin gene only in non-Friedreich ataxia non-ataxia-telangiectasia ataxic patients with AFP level >= 7 mu g/l, is 0.23% and the probability for a non-Friedreich ataxia non-ataxia-telangiectasia ataxic patient to be affected with AOA2 with AFP levels >= 7 mu g/l is 46%. Therefore, selection of patients with an AFP level above 7 mu g/l for senataxin gene sequencing is a good strategy for AOA2 diagnosis. Pyramidal signs and dystonia were more frequent and disease was less severe with missense mutations in the helicase domain of senataxin gene than with missense mutations out of helicase domain and deletion and nonsense mutations (P = 0.001, P = 0.008 and P = 0.01, respectively). The lack of pyramidal signs in most patients may be explained by masking due to severe motor neuropathy

    γ-rays irradiation effects on dielectric properties of Ti/Au/GaAsN Schottky diodes with 1.2%N

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    Dielectric properties of As grown and irradiated Ti /Au/GaAsN Schottky diodes with 1.2%N are investigated using capacitance/conductance-voltage measurements in 90–290 K temperature range and 50–2000 kHz frequency range. Extracted parameters are interface state density, series resistance, dielectric constant, dielectric loss, tangent loss and ac conductivity. It is shown that exposure to γ-rays irradiation leads to reduction in effective trap density believed to result from radiation-induced traps annulations. An increase in series resistance is attributed to a net doping reduction. Dielectric constant (ε’) shows usual step-like transitions with corresponding relaxation peaks in dielectric loss. These peaks shift towards lower temperature as frequency decrease. Temperature dependant ac conductivity followed an Arrhenius relation with activation energy of 153 meV in the 200–290 K temperature range witch correspond to As vacancy. The results indicate that γ-rays irradiation improves the dielectric and electrical properties of the diode due to the defect annealing effect

    Cutoff value for predicting success in triathlon mixed team relay

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    IntroductionThe Mixed-Team-Relay (MTR) triathlon is an original race format present on the international scene since 2009, which became an Olympic event at the Tokyo 2020 Games. The aim of this study was to define the probabilities of reaching a victory, a podium, or a finalist rank in a relay triathlon, according to the position of any of the four relayers (Women/Men/Women/Men) during each of the four segments (leg) of the race.MethodsAll MTR results from the World Series, Continental Championships, World Championships from 2009 to 2021 and Tokyo 2020 Olympics have been collected. We calculated the set of probability frequencies of reaching a given final state, according to any transient state during the race. All results are compared with a V' Cramer method.ResultsThe frequency of winning is similar at the end of Leg 1 for TOP1 (first position) and TOP2-3 (second and third positions). Then, a difference in the winning-associated frequencies is first observed after the Bike stage of Leg 2, where 47% of TOP1 athletes will win, vs 13% of the TOP2-3.DiscussionThis difference continually increases until the end of the race. Legs 2 and 3 are preponderant on the outcome of the race, the position obtained by each triathlete, especially in swimming and cycling, greatly influences the final performance of the team. Leg 1 allows to maintain contact with the head of the race, while Leg 4 sets in stone the position obtained by the rest of the team

    Effect of Co-60 gamma-ray irradiation on electrical properties of Ti/Au/GaAs1-xNx Schottky diodes

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    Current-voltage (I-V), capacitance-voltage-frequency (C-V-f) and conductance-voltage-frequency (G/ω-V-f) measurements at room temperature are used to study 50 kGy 60Co γ-ray electrical properties irradiation dependence of Ti/Au/GaAs1−xNx Schottky diodes with 0.2%; 0.4%; 0.8% and 1.2% nitrogen dilution. This γ-ray irradiation induces a permanent damage that has increased ideality factor and series resistance for all samples. It was accompanied by a decrease in Schottky barrier height with nitrogen content up to 0.4%N and remained constant thereafter. Radiation was also found to degrade the reverse leakage current. At high frequency (1 MHz), capacitance and conductance decreased after radiation due to a decrease in net doping concentration. Interface state density and series resistance were determined from C-V-f and G/ω-V-f characteristics using Hill-Coleman methods. Interface states density exponentially decreased with increasing frequency confirming the behavior of interface traps response to ac signal. Series resistance increases after irradiation is attributed to carrier's removal effect and mobility degradation. It has two peaks in the accumulation and inversion region for some diodes (0.4%N, 0.8%N). γ-ray irradiation produced traps levels and recombination centers that reduce relaxation time. An increase in %N content can impede irradiation damage with even some compensation when the percent of diluted nitrogen is high (1.2%N)
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