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Study of the Convergence of the Increments of Gaussian Process
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作者 Abdelkader Bahram Shaban A. El-Shehawy 《Applied Mathematics》 2015年第6期933-939,共7页
Let be a Gaussian process with stationary increments . Let be a nondecreasing function of t with . This paper aims to study the almost sure behaviour of where with and is an increasing sequence diverging to .
关键词 WIENER PROCESS GAUSSIAN PROCESS Law of the ITERATED LOGARITHM Regularly Varying Function
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Theoretical Investigation of Electronic and Optical Properties of Si/SiGe Quantum Cascade Structures
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作者 Khadidja Zellat Belabbes Soudini Salah Mohamed Ait Cheikh 《Advances in Materials Physics and Chemistry》 2013年第1期19-24,共6页
This paper reviews the basic properties of the SiGe alloy, presents some new results on its electronic and optical properties, and discusses the approach that has been followed to model quantum wells containing SiGe l... This paper reviews the basic properties of the SiGe alloy, presents some new results on its electronic and optical properties, and discusses the approach that has been followed to model quantum wells containing SiGe layers for applications in quantum cascade lasers. The shape of the confining potential, the subband energies and their eigen envelope wave functions are calculated by solving a one-dimensional Schr?dinger equation. The calculations of optical parameters are used to optimize the Si/SiGe quantum cascade structures. Our results are found to be in good agreement with other calculations. 展开更多
关键词 SIGE Alloy Electronic and Optical Properties QUANTUM CASCADE LASERS (QCLs)
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Numerical Simulation of Marine Vehicle Immersed in Water
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作者 Benamar Derrar Benameur Hamoudi +1 位作者 Mohammed El-Amine Dris Fethi Saidi 《Journal of Marine Science and Application》 CSCD 2019年第3期282-294,共13页
This article presents a numerical study of the forces induced by hydrodynamic impact, that is, the impact of a part of the bottom of the hull on the water surface. The prediction of these efforts is often based on num... This article presents a numerical study of the forces induced by hydrodynamic impact, that is, the impact of a part of the bottom of the hull on the water surface. The prediction of these efforts is often based on numerical simulations to determine the shock intensity of a structure on the surface of a weakly compressible fluid (for example, water). The short duration of the impact is also investigated in this work. This phenomenon occurs especially when a ship encounters a harsh and difficult sea conditions. Under such conditions, it is important to know how to predict the hydrodynamic forces applied to the structure to correctly optimize the ship elements during its design stage or to prevent possible damage. Indeed, various factors such as speed of the ship and height of the swell can cause the hull to partially emerge and then fall violently onto the water surface, which is referred to by naval personnel as tossing or slamming causing vibrations, stresses, and fatigue to the structural elements of the ship. In this work, we present an example of phenomenon modeling and then a numerical study of the different geometries (dihedron) that play a role in different sections of the bow. Then, we compare our present results with the theoretical and experimental results of other researchers in the field. The average interval impact time for a dihedral model corresponding to the section of the chosen ship and other experimental and theoretical data is in good agreement with the experimental and theoretical measurements. 展开更多
关键词 SLAMMING HYDRODYNAMIC impact Aero-hydro-elastic Dihedral Fluid/structure interaction MARINE VEHICLE
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Systems Dynamics of Sheep Farms and Driving Herds of Faces to the Vagaries of Weather: Cases from the Region of El Bayadh
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作者 Mekhloufi Moulay Brahim Mahari Latifa Mekhloufi Fadila 《Agricultural Sciences》 2014年第7期583-587,共5页
The cattlemen of the steppe are faced with climate risks whose consequences are at the origin of one of the essential mechanisms of the degradation of resources natural fodder, thus making uncertain the food of livest... The cattlemen of the steppe are faced with climate risks whose consequences are at the origin of one of the essential mechanisms of the degradation of resources natural fodder, thus making uncertain the food of livestock. Thus, faces to the changing socio-economic and climatic risks, the pastoral society has implemented different adaptive strategies to ensure the reproduction of its operating systems. The objective of this study is to analyze the patterns of the use of the space of the pastoral area called El-Bayadh in order to show how the actors adopt and adapt the techniques of production available in order to ensure the security of the production of their exploitation in an environment particularly fragile, hostile and vulnerable. It is therefore to take knowledge of the basic strategies implementation and the responses provided by the livestock producers to protect themselves against the consequences of a difficult climate in order to ensure the conduct of the food needs of their animals and the reproduction of their operating system. 展开更多
关键词 BREEDING System CONDUCT of SHEEP FARMING Climate
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Modelling the monthly hydrological balance using Soil and Water Assessment Tool(SWAT)model:A case study of the Wadi Mina upstream watershed
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作者 Hanane Mebarki Noureddine Maref Mohammed El-Amine Dris 《Journal of Groundwater Science and Engineering》 2024年第2期161-177,共17页
Modelling the hydrological balance in semi-arid zones is essential for effective water resource management,encompassing both surface water and groundwater.This study aims to model the monthly hydrological water cycle ... Modelling the hydrological balance in semi-arid zones is essential for effective water resource management,encompassing both surface water and groundwater.This study aims to model the monthly hydrological water cycle in the Wadi Mina upstream watershed(northwest Algeria)by applying the Soil and Water Assessment Tool(SWAT)hydrological model.SWAT modelling integrates spatial data such as the Digital Elevation Model(DEM),land use,soil types and various meteorological parameters including precipitation,maximum and minimum temperatures,relative humidity,solar radiation and wind speed.The SWAT model was calibrated and validated using data from January 2012 to December 2014,with a calibra-tion period from January 2012 to August 2013 and a validation period from September 2013 to December 2014.Sensitivity and parameter calibration were conducted using the SWAT-SA program,and model performance evaluation relied on comparing the observed discharge at the outlet of the basin with model-simulated discharge,assessed through statistical coefficients including Nash-Sutcliffe Efficiency(NSE),coefficient of determination(R2)and Percent Bias(PBAIS).Calibration results indicated favourable objec-tive function values(NSE=0.79,R2=0.93,PBAIS=-8.53%),although a slight decrease was observed during validation(NSE=0.69,R2=0.86,and PBAIS=-11.41%).The application of the SWAT model to the Wadi Mina upstream watershed highlighted its utility in simulating the spatial distribution of different components of the hydrological balance in this basin.The SWAT model revealed that approximately 71%of the precipitation in the basin evaporates,while only 29%contributes to surface runoff or infiltration into the soil. 展开更多
关键词 SWAT model Performance Parameters RUNOFF GROUNDWATER WADI
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Effect of Sodium Metabisulphite on Blood Metabolic Status of Wistar Rats
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作者 Fatima Zohra El Kadi Amina Imène Bénali +1 位作者 Mohammed Bénali Slimane Belbraouet 《Food and Nutrition Sciences》 2014年第15期1529-1537,共9页
The objective of this work was to determine the sodium metabisulphite (NaMBS) subchronic toxicity used as a food additive in Algeria. Three groups of female Wistar rats were treated with 0.25%, 1% and 4% of NaMBS in t... The objective of this work was to determine the sodium metabisulphite (NaMBS) subchronic toxicity used as a food additive in Algeria. Three groups of female Wistar rats were treated with 0.25%, 1% and 4% of NaMBS in their drinking water for 90 days. An immunization protocol was conducted during the experiment. Mortality, comportmental and weight modifications, and food and water consumption were recorded. At the end of the experiment, the control and experiment rats were killed, and their blood and organs were removed. Immunoglobulin levels were evaluated;biochemical and hematological parameters were investigated. Our results showed that the administration of NaMBS at 1% and 4% had significant effects on body weight, food and water consumed. There was an increase in biochemical parameters (calcium, urea, creatinine, uric acid, transaminases) and decrease immunoglobulin levels. The hematology revealed a decrease in red blood cells and hemoglobin, as well as leucocytosis. Physiological study showed enlarged spleen, kidney, liver and stomach. In light of our results, we can conclude that subchronic intake of NaMBS 1% and 4% seems to alter immune function, biochemical, hematological and physiological para-meters in Wistar rats. 展开更多
关键词 SODIUM Metabisulphite SUBCHRONIC HAEMATOLOGY Biochemistry PHYSIOLOGY WISTAR Rat
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Alleviating Bottlenecks in Power Interconnectors by Means of FACTS
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作者 Rolf Grunbaum Talivaldis Podins 《Journal of Energy and Power Engineering》 2012年第12期2046-2053,共8页
Power interconnections are becoming increasingly important in various parts of the world, as incentives for power exchange between countries are growing. A current example is that the Baltic Energy Market Interconnect... Power interconnections are becoming increasingly important in various parts of the world, as incentives for power exchange between countries are growing. A current example is that the Baltic Energy Market Interconnection Plan is launched by the European Council. For a variety of reasons, it is desirable to keep transmission corridors as slender as possible, i.e. keeping the number of lines as limited as possible, while still keeping adequate stability and power transmission capacity over the corridor. This is true, no matter whether it concerns a green-field project, or if it is a question of expanding an existing transmission corridor into higher power transmission capability. To achieve this, FACTS (flexible AC transmission systems), based on state of the art high power electronics, is a highly useful option, from technical, economical and environmental points of view, to increase the utilization and stability of a transmission system or intertie. The paper presents salient design features as well as benefits of recently installed FACTS devices, more specifically SVC (static var compensators) and series capacitors, for enabling or improving cross-border as well as interregional power transfer in a cost-effective and environmentally friendly way. 展开更多
关键词 FACTS power transmission stability SVC series compensation transient stability voltage stability.
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Physical Properties of the Zn<sub>x</sub>Cd<sub>1-x </sub>Se Alloys: Ab-Initio Method
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作者 Mohammed Ameri Meriem Fodil +3 位作者 Fatma Z. Aoumeur-Benkabou Zoubir Mahdjoub Fatima Boufadi Ali Bentouaf 《Materials Sciences and Applications》 2012年第11期768-778,共11页
The present work performs self-consistent ab initio full-potential linear muffin-tin orbital (FP-LMTO) method to study the structural and electronic properties of the ternary ZnxCd1-xSe alloy, based on density functio... The present work performs self-consistent ab initio full-potential linear muffin-tin orbital (FP-LMTO) method to study the structural and electronic properties of the ternary ZnxCd1-xSe alloy, based on density functional theory (DFT). In this approach, both the local density approximation (LDA) and the generalized gradient approximation (GGA) were used for the exchange-correlation potential calculation. The ground-state properties are determined for the bulk materials CdSe, ZnSe and their alloy in cubic phase. In particular, the lattice constant, bulk modulus, electronic band structures and effective mass. We mainly showed deviation of the lattice parameter and bulk modulus from Vegard’s law of our alloys. We also presented the microscopic origins of the gap bowing using the approach of Zunger et al. The results are compared with other theoretical calculations and experimental data and are in reasonable agreement. 展开更多
关键词 FP-LMTO Ab-Initio Approach of Zunger Effective MASS
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<i>In Vitro </i>Effects of Oil’s Fatty Acids on T-Cell Function of Obese Men
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作者 Asmaa Meraou Hafida Merzouk +4 位作者 Amel Saidi Amel Medjdoub Sid Ahmed Merzouk Mohamed Bénali Slimane Belbraouet 《Food and Nutrition Sciences》 2017年第2期277-293,共17页
Background: Dietary fatty acids have important homeostatic functions in regulating the immune response and may exert beneficial effects on immune alterations during obesity. Objective: To assess the in vitro effects o... Background: Dietary fatty acids have important homeostatic functions in regulating the immune response and may exert beneficial effects on immune alterations during obesity. Objective: To assess the in vitro effects of oil fatty acids, different oils (olive, linseed, Nigel, sunflower) were tested on T-lymphocyte proliferation, Th1- and Th2-type cytokine production, and intracellular oxidant/antioxidant status in obese patients. Methods: Peripheral blood lymphocytes were isolated using Histopaque and were in vitro cultured and stimulated by Con A in the presence or absence of the oils. Cell proliferation, interleukin-2, interleukin-4 and interferon-γ (INFγ) secretions and intracellular oxidative status (glutathione (GSH), malondialdehyde (MDA), carbonyl protein levels, catalase activity and micronuclei frequency) were investigated. Results: Abnormalities in lymphocyte function and intracellular oxidative stress were observed in obesity. Linseed oil induced a reduction in T-lymphocyte proliferation and IL-2 production while Nigel oil increased them in both obese and control groups. In addition, Nigel oil enhanced IFNγ and IL-4 secretion. Olive and sunflower oils had no effect on lymphocyte proliferation and cytokine secretion in both groups. Linseed and Nigel oils induced an increase in T cell GSH concentrations and catalase activity with a concomitant decrease in MDA, carbonyl protein contents and micronuclei frequency especially in obese patients. Conclusion: Linseed and Nigel oils had beneficial effects on lymphocyte proliferation, cytokines secretions and redox status, while olive and sunflower oils had no effects on immune cell function in obesity. 展开更多
关键词 Obesity Lymphocytes Olive OIL LINSEED OIL Nigel OIL SUNFLOWER OIL Cytokines Oxidant/Antioxidant Status
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Vibration Control of FGM Piezoelectric Plate Based on LQR Genetic Search
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作者 Kouider Bendine Rajan L. Wankhade 《Open Journal of Civil Engineering》 2016年第1期1-7,共7页
Active vibration control of functionally graded material (FGM) plate with integrated piezoelectric layers is studied. In this regard, a finite element model based on the classical plate theory is adopted and extended ... Active vibration control of functionally graded material (FGM) plate with integrated piezoelectric layers is studied. In this regard, a finite element model based on the classical plate theory is adopted and extended to the case of FGM plate to obtain a space state equation. Rectangular four node and eight node elements are used for the analysis purpose. The material proprieties of FG plate are assumed to be graded along the thickness direction. In order to control the vibration of the plate, an LQR controller has been designed and developed. The weighing factors are obtained by using genetic algorithm. The proposed results of finite element modeling are verified with the results obtained using ANSYS. Also the validation of methodology is done with comparing the results with that of available in literature and found in well agreement. Further analysis is performed for three sets of power law exponent n = 0, 1 and 100 which gives benchmark results for vibration control of FGM piezoelectric plate. 展开更多
关键词 Functionally Graded Material PIEZOELECTRIC LQR Controller Genetic Algorithm
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真空断路器频繁开合电容器组性能研究
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作者 刘勇 吕育蓉 +1 位作者 Dietmar Gentsch Alessandro Bonfanti 《电气时代》 2025年第12期135-140,共6页
电容器组补偿是在中压电力系统中广泛采用的无功补偿方式,且补偿装置每天都需要投入和切除。以K系列灭弧室为对象,按IEC62271-100和GB/T1984标准,在40.5KV下开展3轮C2级1250 A背靠背电容器组开合试验,分析预击穿电场分布、合闸涌流形态... 电容器组补偿是在中压电力系统中广泛采用的无功补偿方式,且补偿装置每天都需要投入和切除。以K系列灭弧室为对象,按IEC62271-100和GB/T1984标准,在40.5KV下开展3轮C2级1250 A背靠背电容器组开合试验,分析预击穿电场分布、合闸涌流形态与能量分布。264次试验后,K系列灭弧室断口绝缘性能符合GB/IEC标准,触头表面粗糙度和熔焊情况均有明显改善。K系列真空灭弧室抗熔焊能力强,受关合涌流影响小,适用于电容器组回路频繁开合。 展开更多
关键词 电容器组 预击穿电场 真空断路器 性能研究
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Some Uniqueness Results for Functional Damped Semilinear Differential Equations in Fréchet Spaces
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作者 Abdelghani OUAHAB 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2008年第1期95-106,共12页
A recent nonlinear alternative for contraction maps in Frechet spaces due to Frigon and Granas (Resultats de type Leray-Schauder pour des contractions sur des espaces de Frechet, Ann. Sci. Math. Quebec 22, (2), 161... A recent nonlinear alternative for contraction maps in Frechet spaces due to Frigon and Granas (Resultats de type Leray-Schauder pour des contractions sur des espaces de Frechet, Ann. Sci. Math. Quebec 22, (2), 161-168 (1998)), combined with semigroup theory, is used to investigate the existence and uniqueness of mild solutions for first- and second-order functional semi linear and neutral damped differential equations in Frechet space. 展开更多
关键词 differential equations DAMPED SEMIGROUP family cosinus mild solution fixed point UNIQUENESS Frechet spaces CONTRACTION
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Antibacterial activity of essential oil of north west Algerian Eucalyptus camaldulensis against Escherichia coli and Staphylococcus aureus
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作者 Bachir Raho Ghalem Benali Mohamed 《Journal of Coastal Life Medicine》 2014年第10期799-804,共6页
Objective:To evaluate the in vitro antimicrobial activities of the crude oil of Eucalyptus camaldulensis(E.camaldulensis)leaves.Methods:The essential oils of E.camaldulensis harvested from the garden of the Health Cen... Objective:To evaluate the in vitro antimicrobial activities of the crude oil of Eucalyptus camaldulensis(E.camaldulensis)leaves.Methods:The essential oils of E.camaldulensis harvested from the garden of the Health Center in Sidi Bel Abbes city(North West of Algeria),were screened for their antibacterial activities against two clinical bacteria[Escherichia coli(E.coli),Staphylococcus aureus(S.aureus)]by the agar disc diffusion method and broth dilution susceptibility assay.Results:The diameter of zones of inhibition by the leaf extracts of E.camaldulensis was 10-31 mm and 10-26 mm respectively for E.coli and S.aureus.Gram positive S.aureus was more resistant to tested essential oil than Gram negative E.coli.Conclusions:The results suggested a potential antimicrobial activity of the essential oil of E.camaldulensis,which may find its application in future research for the food and pharmaceutical industry. 展开更多
关键词 Eucalyptus camaldulensis Essential oils Antibacterial activity Escherichia coli STAPHYLOCOCCUSAUREUS
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Numerical simulation of corona-induced vibration of high voltage conductor
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作者 A.GOURBI M.BRAHAMI +1 位作者 A.TILMATINE P.PIROTTE 《Frontiers of Electrical and Electronic Engineering in China》 CSCD 2009年第3期335-341,共7页
When it rains,electric power transmission lines start vibrating due to corona effect.This type of vibration is known as“corona-induced vibration”.The aim of this paper is to elaborate a mathematical model for numeri... When it rains,electric power transmission lines start vibrating due to corona effect.This type of vibration is known as“corona-induced vibration”.The aim of this paper is to elaborate a mathematical model for numerical simulation of the corona-induced vibration,with consideration of the influence of the magnitude and the polarity of the electric field on the conductor surface.Finite element method was employed to develop the numerical model,and the finite difference method was used for the time discretisation.The moment of application of the coronainduced force is evaluated using the resultant vertical force applied to a water drop,suspended under a high voltage conductor.Some experimental results of other authors are exploited to evaluate the precision of the simulation and the validation of numerical results. 展开更多
关键词 corona-induced vibration corona wind finite element method
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