DSpace univ-abess laghrour@khenchela
DSpace is the world leading open source repository platform
- Dspace Administrator = biblio.central@univ-khenchela.dz
Communities in DSpace
Select a community to browse its collections.
- كلية العلوم الاقتصادية و العلوم التجارية
- كلية العلوم الانسانية و الاجتماعية
- كلية الحقوق و العلوم السياسية
- كلية الآداب و اللغات
- كلية العلوم الطبيعية و الحياة
Recent Submissions
Synthesis, structural, electrochemical and tribological characterization of nanostructured compound based on titanium (Ti-Ni) for biomedical applications
(2025) Bouchareb Nabila
Medical implants are essential for improving the quality of life of people who suffer, especially in the orthopedic field. Therefore, the need for biomaterials has increased exponentially as a result of the necessity for replacing or repairing damaged parts of the human body to regain the missing shape or functionality of biological tissue. To achieve the long-term performance of these implants, they must have distinct mechanical, tribological, and electrochemical properties.
In this context, this study aims to examine the effect of milling times on the mechanical, tribological, and electrochemical properties of Ti50-Ni50 (or Nitinol), which is one of the most attractive materials in the medical field for orthopedic implants due to its unique properties.
Ti50-Ni50 alloys were synthesized using high-energy ball milling under different milling times (2, 6, 12, and 18 h). The size, shape, and uniform chemical composition of the powder particles were examined using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The alloyed particles' structural characteristics were determined through the use of X-ray diffraction (XRD). Mechanical properties were assessed using hardness tests, while tribological behavior was examined using a ball-on-plate tribometer operating in Ringer's Solution under various applied load of 2, 10, and 20 N. The electrochemical properties were characterized by open-circuit potential (OCP) measurement, potentiodynamic polarization (PD), and the Electrochemical Impedance Spectroscopy (EIS) technique. To simulate typical biological conditions, Hank's solution at pH = 7.4 and T = 37 °C were used as the electrolyte.
The results revealed that the milling process influences the particle size and shape of powders, where the proportion of fine particles increased with increasing grinding times from 2 h to 18 h due to severe deformation and fracturing. This improvement in particle refinement contributed to enhanced mechanical attributes, wear resistance, and corrosion resistance, making the material useful for bone implants.
Improving the effectiveness of clay minerals for the removal of heavy metals
(2025) Rim Imen
The discharge of heavy metals into the environment represents a significant threat to ecosystems and human health. Among the available strategies, adsorption is widely considered to be the most promising due to its clarity, affordability, and high efficiency in eliminating metal ions, even in small amounts.
The objective of this thesis is to enhance the adsorbent capacity of kaolin-type (from Guelma, east of Algeria) clays through chemical means, with the subsequent intention of utilizing these materials to remove heavy metals from an aqueous phase.
The initial modification entailed the use of diphenylamine to synthesize DPA-Kaolin, with the objective of efficiently removing lead (II) and copper (II) from aqueous solutions. The subsequent modification involved the modification of kaolin with surfactants (SLS, SDBS, and their mixture), with the aim of efficiently removing mercury (II) from aqueous solutions.
The characterization of the samples was conducted through a range of analytical methodologies, encompassing X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) to ascertain their structural composition. In addition, scanning electron microscopy (SEM), energy dispersive X-ray (EDX) and Brunauer-Emmett-Teller (BET) analysis were employed to determine their morphological characteristics.
The findings showed an increase in the BET specific surface area of kaolin by nearly 25% (from 66.69 m².g−1 to 71.35 m².g−1) after DPA modification, and this increase demonstrated significantly greater maximum adsorption capacities for Pb(II) and Cu(II) on DPA-kaolin than on Nat-kaolin, with values of 151 μmol.g-1 and 134 μmol.g-1, respectively, suggesting an enhanced adsorption capacity, which confirmed the successful modification of kaolin using DPA.
Conversely, the specific surface area of kaolin increased significantly with the addition of surfactants, reaching 38.3%, 31.9%, and 17.5% for K-SLS, K-SDBS, and K-M, respectively. This finding indicates that the mercury adsorption capacity of kaolin modified with anionic surfactant SLS surpasses that of kaolin modified with a mixture of surfactants (SLS+SDBS) and finally kaolin modified with anionic surfactant SDBS. The corresponding values for mercury adsorption capacity were determined to be 17.77mg.g-1, 15.77mg.g-1, and 13.45 mg.g1, respectively.
Contribution to the Specification and Formal Analysis of Cyber-Physical Systems: Application to Industry 4.0
(2025-05-25) Ayoub BOUHEROUM
Cyber-Physical Systems (CPS) operate across different spatial and
temporal scales and exhibit complex, context-dependent behaviors.
The intricate nature of CPS poses significant conceptual and technical
challenges, as understanding and managing such systems often
exceed individual capacities. To address these challenges, advancements
in modeling languages, formal methods, and tools are essential,
alongside interdisciplinary collaboration among domain experts, formal
methods researchers, and tool developers.
This thesis proposes a multi-phase and iterative approach for designing,
defining, and analyzing the dynamic and secure behavior of CPS,
addressing the gap between theoretical formal methods and their
practical application in CPS development.
First, adhering to the principles of ISO/IEC/IEEE 42010:2021 for
architectural descriptions, we develop a metamodel that facilitates
effective communication among stakeholders by employing architectural
views and viewpoints. This approach ensures consistency and
fosters a shared understanding of the system architecture.
Second, to address the limitations of existing formalisms, we introduce
CA-BRS, a novel model that combines Bigraphical Reactive
Systems (BRS) and Control Agents. CA-BRS distinguishes between
the virtual, physical, and cyber levels of CPS, using abstract agents
and bigraphs to specify these dimensions. It also incorporates Controlled
Reaction Rules to represent both physical and cyber evolutions
while considering material constraints. To analyze CPS behavior,
we define a formal computational model, the Guided Transition
System (GTS), which captures and evaluates emergent properties
such as security and safety.
IThird, in the design phase of CPS, we establish mapping rules to define
the behavioral semantics of CA-BRS using BPMN activity diagrams.
This enables the detection of functional inconsistencies, such
as deadlocks, infinite loops, or multiple terminations, during model
execution. Additionally, we extend CA-BRS to address security requirements,
ensuring data confidentiality and integrity by preventing
unauthorized access and modifications in distributed CPS.
Finally, we demonstrate the practicality of our approach through a
case study on Medical-CPS and Industry 4.0 (I4.0-CPS), focusing on
network routing (Access Control Lists) and data confidentiality in
Electronic Health Records. This highlights the balance between theoretical
insights and practical considerations in addressing the physical,
cyber, and safety dimensions of CPS.
AGRONOMIE I : EAU ET SOL
(UNIVERSITE ABBES LAGHROUR KHENCHELA, 2025) Laiche AOUIDANE
L'agronomie, science clé pour une gestion durable des ressources naturelles, est au coeur des enjeux actuels liés à la sécurité alimentaire et à la préservation de l'environnement. L'eau et le sol, deux éléments fondamentaux de l'agriculture, sont au centre de nombreuses problématiques et nécessitent une compréhension approfondie pour garantir un développement agricole respectueux de l'environnement et des générations futures.
Ce polycopié de cours est destiné aux étudiants de deuxième année en sciences agronomiques, et plus particulièrement à ceux qui s'intéressent aux fondamentaux de l'agronomie, de l'eau et des sols. L’objectif de ce cours est de vous fournir une compréhension approfondie des principes de base qui régissent les interactions entre le sol, l'eau et les pratiques agricoles. Ainsi, le programme s'articule autour des concepts théoriques et des applications des connaissances acquises, afin de poser les bases nécessaires à une approche scientifique des systèmes agricoles.
L'eau et le sol sont des ressources naturelles essentielles pour l'agriculture. Cependant, la gestion de ces ressources est complexe, nécessitant une compréhension rigoureuse de leurs propriétés physiques, chimiques et biologiques de ces deux ressources. Ce polycopié met l’accent sur les notions fondamentales liées aux cycles de l'eau, à la composition et à la structure des sols, ainsi qu'aux principes de leur gestion durable dans un cadre agricole, dans le cadre de donner une vision globale sur l’importance de ces ressources dans le développement de l’agriculture.
حماية اللاجئين من الابعاد القسري في القانون الدولي
(كلية الحقوق والعلوم السياسية جامعة عباس لغرور, 2025-06) شراف الدين منال; ليتيم فاطمة الزهراء
يُعدّ مجلس حقوق الإنسان التابع للأمم المتحدة الهيئة الحكومية الدولية الرئيسية للأمم المتحدة، والآلية الدولية المعنية بتعزيز حماية حقوق الإنسان، ومعالجة جميع قضايا انتهاكات حقوق الإنسان وتقديم التوصيات في هذا المجال. إلا أنه تعرّض لانتقادات عديدة أثرت على فاعليته، وهو ما دفعنا إلى البحث فيه لمعرفة العوامل التي تحد من عمله، سعيًا إلى إصلاحه ومعالجة أوجه القصور فيه.The United Nations Human Rights Council is the principal intergovernmental body of the United Nations and the international mechanism for strengthening the protection of human rights, addressing all human rights violations, and making recommendations in this area. However, it has been subject to numerous criticisms that have affected its effectiveness. This prompted us to investigate the factors limiting its work, with the aim of reforming it and addressing its shortcomings.