Institutional repository of university M'Hamed Bougara Boumerdes
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Élaboration d'un plan de développement du champ «MLN» pour assurer un prolongement du plateau de production
No full text91 p. : ill. ; 30 cmDans l'industrie pétrolière, les études en génie de réservoir visent principalement à optimiser la production et à maximiser les bénéfices tout au long du cycle de vie d'un gisement. La simulation en génie de réservoir est essentielle pour atteindre ces objectifs, car elle permet de créer, analyser, étudier et comparer divers scénarios de réservoir afin d'identifier les résultats les plus efficaces. Cette étude se concentre sur l'évaluation des indices de production et des potentiels du réservoir KGB dans la région de MLN, et propose plusieurs techniques de récupération assistée pour améliorer l'extraction d’huile et prolonger la durée du plateau de production. Cela est réalisé grâce à l'injection alternée de gaz et d'eau (WAG) utilisant un modèle de fluide compositionnel, ainsi qu'en proposant le forage de nouveaux puits. Cette analyse technique nous a permis de prendre des décisions éclairées pour améliorer les performances techniques et économiques du réservoir
Effect of repair patch nature on J-integral reduction in notched plates
No full textPurpose: The purpose of this research is to evaluate the effectiveness of different repair patch materials in reducing the stresses at the crack tip of a 2024-T3 aluminum plate. This involves a numerical analysis using the finite element method (FEM) to estimate the reduction in the J-integral value, with the goal of identifying how various parameters related to the patch materials, adhesive properties and loading conditions influence the structural integrity of the repaired plate. Design/methodology/approach: The methodology of this research involves conducting a numerical analysis using the FEM to estimate the reduction in the J-integral value at the crack tip of a 2024-T3 aluminum plate. Three types of patches – metal, composite and functionally graded material (FGM) – were examined under tensile loading conditions, and Adekit-A140 adhesive was used to bond these repair patches to the aluminum plate. Findings: The analysis considered various parameters, including crack length, the nature of fibers in the composite material, the gradation exponent for FGM patches and the nature of the face in contact with the adhesive for the FGM patch. Additionally, stress analysis was conducted, examining the J-integral values for the plate, shear stress in the adhesive layer and peel stress in the composite patch. The findings highlight that modifying the nature of the repair patch used can significantly enhance the structural integrity of the repaired plate. Originality/value: The study analyzed J-integral values, shear stress in the adhesive and peel stress in the composite patch. Various parameters, including crack length, fiber type, gradation exponent and adhesive contact face nature, were considered. Results demonstrate that the J-integral value can be significantly reduced by altering the repair patch type, highlighting the effectiveness of customized patch materials in enhancing structural integrity
Course Handout Physical Chemistry of Surfaces and Interfaces : This handout is intended for students enrolled in Master (M2) Specialty: Analytical Chemistry
No full textThe content of the Physical Chemistry of Surfaces and Interfaces unit is designed to align with the analytical chemistry master's degree program offered at Boumerdes University, cov-ering all aspects indicated in this educational field. While much of the content is conventional in nature and addresses the fundamentally important aspects of Physical Chemistry of Sur-faces and Interfaces, it also comprehensively covers essential aspects of General and Physical Chemistry. This includes the chemical and physical properties of material surfaces, reactions on solid catalysts, metal corrosion, surface construction at the atomic level, terminology re-lated to bulk crystals, interfacial phenomena such as surface tension, wetting, and adsorption, along with electrical and intermolecular forces. Additionally, fundamental experimental methods for measuring these phenomena are introduced. The topics are presented in a stu-dent-friendly manner, with worked examples and questions provided within each chapter. This guidebook aims to offer students a clear and straightforward presentation of these prin-ciples, avoiding overly complex mathematical treatments that may obscure understanding. Throughout the book, equations are provided to illustrate methods and relationships, helping students relate theoretical principles to practical situations. While this course guide does not aim to be a comprehensive compendium of facts, students are encouraged to consult other textbooks listed in the bibliography for additional resources to solve practical problems re-lated to each topic. In order words, the course book is only skeleton which students must flesh and it serves as a framework that students must build upon. It is a valuable contribution to the discipline and profession of chemistry and will prove beneficial to students and begin-ning teachers in institutions and universities....
Effect of heat stress on Apis mellifera intermissa and Apis mellifera sahariensis in laboratory controlled conditions: a physiological approach
No full textThe effects of heat on honey bees have received attention in many subspecies. Nevertheless, some subspecies still remain unexplored. In this study, we investigate for the first time the effect of heat on two subspecies of honey bees endemic to Algeria, Apis mellifera intermissa which is adapted to the Mediterranean climate and Apis mellifera sahariensis, which is adapted to the hot climate of southwest Algeria. We tested the hypothesis that sahariensis is more tolerant to heat stress than intermissa. In two in-vitro tests, we reared workers of both subspecies at 4 temperatures (34 °C, 38 °C, 39 °C, and 40 °C). Then, we determined the hemolymph protein (HP) concentration, hypopharyngeal gland development (HPG), ovary development and survival. We found that the sahariensis had HPG more developed and less affected by heat than intermissa. Conversely, although intermissa had more (HP) at 34 °C, we found a significant increase in (HP) at 38 °C, 39 C° and 40 °C in intermissa than sahariensis. Although ovary development is greater in intermissa than sahariensis at 34 °C and greater at 34 °C than 38 °C, 39 °C and 40 °C, we did not record differences in ovary development between the subspecies at 38 °C, 39 °C, and 40 °C. Finally, in all conditions, sahariensis had a higher survival than intermissa
Contribution à l’amélioration des performances du fonctionnement d’une pompe à jet de production du pétrole
No full text61 p. : ill. ; 30 cmL'objectif principal de notre travail est d'améliorer les performances de pompe à jet en optimisant leur conception et fonctionnement. En utilisant le logiciel ANSYS-CFX, l'étude analyse le comportement hydraulique des systèmes de pompage, évalue les débits, les pressions et les pertes de charge, et visualise les profils de vitesse et les champs de pression à l'intérieur des pompes. Les résultats montrent que pour une efficacité optimale de 56,42 %, le fluide de puissance doit être pompé à une pression d'injection de 28158 Pa avec un débit de 7,33 kg/s dans une pompe de 20 mm de rayon. L'étude conclut que l'eau est le fluide de puissance le mieux adapté, notamment pour les puits à haute salinité, et recommande des études supplémentaires pour maximiser l'efficacité et la pression de sortie, ainsi que l'intégration de systèmes de surveillance en temps réel pour améliorer la fiabilité des opérations de pompage
Transient stability enhancement of interconnected power systems via coordinated tuning of wide-area damping controllers employing novel social grey wolf metaheuristic optimization
No full textPower system stability challenges arising from low-frequency oscillations are becoming increasingly acute due to the inefficiency of local damping controllers. This paper proposes a two-level architecture for wide area damping controllers (WADCs), optimized by a novel Social Learning Grey Wolf Optimizer (SLGWO) to increase the damping of critical inter-area modes, utilizing an objective function based on the integral of the time-weighted absolute error. The grey wolf optimizer (GWO) suffers from poor exploitation and local optimum trapping, primarily due to its reliance on the three fittest individuals for optimization. The SLGWO tackles these limitations by incorporating a social learning strategy, which facilitates the collective sharing of useful information among individuals, enabling them to enhance accuracy. Additionally, a computationally cheap elitist learning strategy propels the leading wolves to explore better regions, while a nonlinear control parameter is employed to optimize the exploration–exploitation trade-off. The performance of the SLGWO is benchmarked on 21 well-known test functions and compared against the original GWO, Bat Algorithm (BA), Whale Optimization Algorithm (WOA), Harris Hawks Optimization (HHO) algorithm,and Hippopotamus optimization(HO) algorithm. The comparison results are statistically confirmed using the Friedman test, confirming the superiority of the proposed approach. The effectiveness of the proposed WADCs is assessed through nonlinear simulations in the 10 machine 39 bus New England power system under severe disturbances, demonstrating a significant increase in the damping of inter-area oscillations
Wireless Power Transfer Optimization Using Meta-heuristic Algorithms
No full textThe importance of Wireless Power Transfer (WPT) technology in biomedical implants to mitigate the risk of regeneration has increased significantly in recent years. WPT systems are dependent on key parameters such as the coupling coefficient (K), quality factor (Q), and mutual inductance (M), which play a crucial role in determining power transfer efficiency. These parameters are closely related to the geometric characteristics of the coils involved. Therefore, this study explores various meta-heuristic algorithms to search for optimal parameters that maximize power transfer efficiency. The initial results demonstrate that these algorithms perform well across different iterations. To confirm these findings, the study conducted comprehensive validation using Ansys Maxwell software to verify the optimal values obtained through optimization
Characterization of non-rhizobial endophytic bacteria in algerian cowpea root nodules: unveiling potential for nitrogen fixation
No full textThe study aimed to characterize the culturable endophytic bacteria present in cowpea nodules (Vigna unguiculata L. (Walp)). Five endophytic non-rhizobial isolates (SVU1, SVU3, SVU9, SUV15, and SUV18) were isolated from the root nodules of cowpea. Phylogenetic analysis of 16S rRNA gene sequences revealed that the isolates belonged to the genus Paenibacillus, Serratia, Microbacterium, Bacillus and Lysinibacillus. Unlike rhizobia, all five isolates absorbed Congo Red contained in the Yeast Mannitol Extract medium. The nitrate reductase test was positive for all strains except SVU18and all strains utilized, mannitol, inositol and sucrose as substrates. The oxidase reductase test was negative. The results indicated that the root nodules of the legume could host a diverse endophytic community associated with cowpea, representing the first report of endophytic bacteria from Algerian cowpea nodules. These findings shed light on a part of the diversity of non-rhizobial within the cowpea nodules. The findings about the nifH gene showed that these bacteria open avenues for further exploration of the potential applications of endophytic bacteria in promoting nitrogen fixation and enhancing plant growth. Future studies will explore the potential application of these strains in nitrogen fixation and growth promotion for sustainable agriculture
دروس في اقتصاد المؤسسة : مطبوعة بيداغوجية موجهة لطلبة السنة الأولى جذع مشترك، قسم علوم التسيير
No full text104 p.,ill.;30cm
The Energy Transition Experiment in Germany
No full textGermany spearheads global energy transition, transitioning from fossil fuels to diverse renewables like solar, hydro, wind, biomass, and geothermal energy. This shift is supported by adherence to standards and evolving legal frameworks in line with energy transition goals. Germany leads European scientific research, with a focus on private sector involvement. These efforts yield positive outcomes in the German energy market, fostering renewable infrastructure development and a steady rise in their energy supply contribution