SACM - France
Permanent URI for this collectionhttps://drepo.sdl.edu.sa/handle/20.500.14154/9654
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Item Restricted Additive Manufacturing of Ferromagnetic Components by Inkjet Printing Followed by Sintering(Saudi Digital Library, 2025) Gishlan, Lujain; Carreno-Morelli, EfrainThis study explores three different additive manufacturing processes using Fe6.5Si: Solvent on Granules 3D Printing (SG-3DP), Binder Jetting (BJT), and Laser Powder Bed Fusion (LPBF). Their ability to produce dense parts with optimized magnetic properties was compared. Two different Fe6.5Si powders were used during this project. One was sourced from Hoganas, while the other was sourced from HLPowder. Both powders were characterized in terms of density and flowability. Parts printed with SG-3DP achieved positive results as their density averaged of around 95%. Cubes and shells were printed and the shells resulted in a stronger <001> crystallographic texture compared to that of the cube, which is beneficial for magnetic applications. Multiple parameters printing parameters were tested with LPBF printing before obtaining parts that yielded an average density of around 99% and were less prone to cracks. Crystallographic orientations varied depending on the part, with the reference cubes exhibiting a more dominant <111> texture, while the Hilbert cross-sectional parts exhibited a more dominant <101> texture. Magnetic testing of toroidal parts fabricated with the SG-3DP and LPBF showcased the same magnetic saturation of 1.5T. However, the LPBF toroid performed better than the SG-3DP toroid in terms of permeability (164), coercivity (346 A/m), and in terms of power losses (12.7 W/kg).4 0Item Restricted Encapsulation of Acidic Alpha-Glucosidase(Saudi Digital Library, 2024) Aldawod, Dana; Sevarika, Boris; McNeil, ScottLysosomal storage diseases are a group of heritable metabolic disorders characterized by a deficiency of specific enzymes within the lysosome, leading to the accumulation of undegraded substrate, which results in cellular damage and dysfunction. There are over 50 types of LSD, but the most common one that occurs in babies and children is pompa disease. Pompa disease is caused by the deficiency of acid α-glucosidase enzyme, leading to glycogen buildup in lysosomes of different tissues and organs. This condition manifests in symptoms such as muscle weakness, respiratory issues, and cardiac abnormalities. The current treatment option is enzyme replacement therapy, which involves the intravenous administration of the deficient enzyme. However, this treatment suffers from different side effects, such as immunogenicity, poor bioavailability of the enzymes in the lysosomes where they are needed, and low efficacy levels. To overcome these side effects and improve the treatment efficacy, we propose enzyme encapsulation into the liposomes as the main strategy. In this project, we aim to develop liposomes with high encapsulation efficiency for the enzyme while preserving the enzyme's activity. To achieve this goal, we investigated the manufacturing process and identified the optimum manufacturing conditions as well as optimal lipid composition that can allow us to achieve high efficiency in the encapsulation process. In the liposome preparation, the particles were characterized and purified, and the encapsulation efficiency was determined using the direct method (HPLC). Additionally, we assessed the activity of the enzyme encapsulated in the particles, and we evaluated enzyme activity under various conditions and with different substances. We successfully elucidated the optimum manufacturing condition and identified the ideal lipid composition having a high encapsulation efficiency of up to 50 %. The encapsulation strategy is based on the induction of charge-based interaction between protein and liposome, which involves electrostatic interaction between the positively charged lipids and the negatively charged acidic alpha-glucosidase used in this study. The activity of the enzymes was high even after encapsulation. Our data confirm that the efficient encapsulation of the enzymes into lipid vesicles is possible.7 0Item Restricted Digitalization and Internationalization: Assessing Digital Maturity’s Impact on the Internationalization Speed and Performance of Saudi SMEs’ Global Expansion(Saudi Digital Library, 2025) Babgi, Mnahel; PACHÉ, Gilles; SHAJARI, BenyaminThis doctoral dissertation explores the role of digitalization and internationalization in driving company growth, with a particular focus on small and medium-sized enterprises (SMEs). As a powerful duo, these trends present both opportunities and challenges, requiring SMEs to adapt and reconfigure their performance models. Despite significant attention to this topic, there remains a need to synthesize and categorize diverse contributions to gain a deeper understanding of how digitalization and internationalization have evolved. This study employs a three-stage methodology: first, a bibliometric analysis; second, theoretical and conceptual assessments; and third, a comprehensive survey evaluating digital capabilities. By linking digital proficiency to rapid international expansion and SME performance, this research provides valuable insights into the intersection of digitalization and global business growth. The goal is to establish a strong foundation for future research and debate on this critical subject. A bibliometric analysis of 246 publications in international business research was conducted to establish a contextual understanding of digitalization, followed by a front analysis to further refine these findings. Perspectives for future research are also explored. Additionally, the study assesses traditional SME internationalization models and introduces an alternative, capabilities-based digital maturity model designed to accelerate SME internationalization. This advancement calls for an expansion of the resource-based view (RBV) theory to incorporate digitalization-related capabilities. The proposed model features a matrix of eight key capabilities to assess an SME’s digital maturity, along with two components of internationalization speed: the speed of committing to these capabilities and the speed of developing them. Finally, drawing on digital maturity theory, this research explores the impact of eight digital capabilities on SME internationalization and overall performance. Based on responses from 164 Saudi SMEs, the findings confirm that higher levels of digital maturity positively influence both the speed of internationalization learning and the speed of committing to international markets. Additionally, the results indicate that internationalization speed has a positive effect on SME performance. However, in contrast to previous literature, some strategic elements of digital maturity were not supported. Despite this, the study provides empirical evidence to guide SMEs in leveraging digitalization to enhance both internationalization and performance. This doctoral dissertation offers valuable insights for practitioners and policymakers, underscoring the strategic role of digital maturity in SMEs within emerging economies.1 0Item Restricted Stratégies d'enseignement de FLI face à l'hétérogénéité linguistique : Le cas de l'association Cardek à Strasbourg(Saudi Digital Library, 2025) Barnawi, Bashayer; Candas, PeggyCe mémoire explore les stratégies d’enseignement adaptées en Français Langue d’Intégration (FLI) pour faire face à l’hétérogénéité linguistique dans un cadre associatif. Le terrain de l’étude est l’association Cardek, qui accueille des adultes migrants aux profils linguistiques et scolaires très variés. Afin de rendre compte au plus près de la réalité des classes, notre recherche s’appuie sur quatre études de cas (niveaux A0 et A2) impliquant trois intervenantes (une enseignante et deux bénévoles). L’objectif de cette étude est d’identifier les stratégies concrètes utilisées pour maintenir tous les apprenants dans l’apprentissage malgré des niveaux très hétérogènes, et de comprendre les facteurs qui orientent ces choix (niveau, composition linguistique du groupe, posture professionnelle, ressources disponibles). Nous avons mené une recherche qualitative en mobilisant deux outils principaux : l’observation non participante des cours et des entretiens semi-directifs menés après les séances. Les données ont été recueillies à l’aide d’enregistrements audio, puis transcrites selon la norme ICOR. Pour l’analyse, nous avons procédé à une triangulation du « dire » et du « faire » à l’aide d’un tableau comparatif. Un codage thématique inductif a ensuite été réalisé et synthétisé dans un mini-codage, permettant de faire émerger des régularités ainsi que des nuances entre les cas étudiés. Les résultats mettent en évidence cinq familles de stratégies complémentaires : 1. Gestion des langues / médiation plurilingue : français comme langue de travail prioritaire, avec tolérance ponctuelle et encadrée de la L1 entre apprenantes pour lever un blocage (un cas impose plus strictement le français, avec exceptions limitées). 2. Explicitation multimodale et accompagnement : combinaison du verbal, de gestes, de supports visuels (mimes, dessins, images) et guidage de proximité (reformulations, feedback immédiat) pour sécuriser la compréhension. 3. Motivation et engagement : valorisation des efforts, apprentissage par les pairs, corrections collectives pour soutenir l’attention et encourager la persévérance. 4. Différenciation des processus et activités : alternance individuel/binômes/petits groupes, tâches à paliers et ajustements selon le niveau et les objectifs. 7 5. Ingénierie et adaptation des ressources : bricolage didactique (étiquettes-syllabes, images, routines de tableau) et recours à des outils techniques ciblés (par exemple, traducteur téléphonique en dernier recours). Dans l’ensemble, les intervenantes cherchent à trouver un équilibre pragmatique entre immersion en français et sécurisation des apprentissages : réduire l’insécurité linguistique, clarifier les consignes, étayer brièvement puis autonomiser les apprenants. Les choix observés apparaissent sensibles au niveau (A0/A2), à la composition linguistique (forte présence d’arabophones), au contexte associatif (moyens matériels limités) et aux représentations professionnelles (place accordée à la L1, priorité donnée à l’écrit ou à l’oral). Cette recherche met ainsi en lumière des gestes professionnels ajustés et transférables pour la gestion quotidienne de l’hétérogénéité en FLI, tout en soulignant l’intérêt d’un cadre partagé sur l’usage raisonné de la L1 et d’une mutualisation des pratiques efficaces au sein d’équipes mixtes (enseignantes/bénévoles).3 0Item Restricted The Impact of Staff Limitations on Service Quality and Organizational Performance in Hospitality Industry across Saudi Arabia.(Saudi Digital Library, 2025) Aldhabaan, Nuwayyir Mohammad Abdulmohsen; Lazarev, MarijaThe research examined how staffing limitations affected service quality and organizational performance within the hospitality industry in Saudi Arabia. The research was guided by the SERVQUAL framework, the Service-Profit Chain, and human-resource performance models to identify how shortages in staff numbers, skills, and experience influenced hotel operations. A qualitative design was adopted, and data were collected through semi-structured interviews with three hospitality professionals working in operational, human-resources, and international roles. The interview data were analyzed using thematic analysis. The findings indicated that a limit in staffing generated huge operational pressure, increased workload stress, and reduced employee motivation, resulting in noticeable declines in responsiveness and reliability, both are important in service quality. Recruitment challenges related to Saudization policies, skill mismatches, and turnover were found to intensify these issues. Training and development practices partially mitigated the negative effects, although such practices were less structured compared with international benchmarks such as Switzerland. The study concluded that staffing limitations have a direct and measurable impact on service consistency, guest satisfaction, and organizational performance in Saudi hotels. Recommendations were provided for improving workforce planning, training systems, and employee retention strategies to support the sustainable development of the sector.2 0Item Restricted OPTIMAL CONTROL OF SOME CLASSES OF SWEEPING PROCESSES AND APPLICATIONS(Saudi Digital Library, 2025) Alsharief, Laila; Jourani, AbderrahimThis thesis investigates the optimal control of dynamical systems governed by sweeping processes, with a particular focus on both implicit and explicit formulations involving convex and polyhedral geometries. These systems, characterized by highly nonsmooth differential inclusions with state-dependent constraints, arise naturally in models of elasto-plasticity, hysteresis, and contact mechanics. The primary challenge in controlling such systems arises from the discontinuous nature of the normal cone operator, which obstructs the direct application of classical optimal control tools. We begin by establishing a Pontryagin-type maximum principle for a class of optimal control problems governed by implicit sweeping processes with general endpoint constraints. The sweeping set is assumed to be polyhedral and control-dependent, and the dynamics include state and control variables in both the inclusion and perturbation terms. The analysis relies on precise coderivative estimates for the metric projection mapping onto polyhedral convex sets. Applications include variational inequalities and projected dynamical systems, such as generalized Lotka–Volterra models. To support this framework, we conduct a detailed study of the coderivative geometry of projection operators. We present new estimates for the Dini and Mordukhovich coderivatives of the metric projection mapping, focusing on two important classes of convex sets: those with strictly Hadamard differentiable boundaries and polyhedral sets. These results are instrumental in handling the nonsmooth structure of sweeping processes and form a critical component in deriving necessary optimality conditions. We further propose a novel approximation scheme for solving optimal control problems governed by explicit sweeping processes, which are inherently more challenging due to their nonsmoothness. By introducing a family of implicit sweeping dynamics, we regularize the system in a way that enables the application of classical maximum principle techniques. We establish convergence results and validate the method through an application to the optimal control of a single degree-of-freedom elasto-plastic oscillator, a benchmark model in structural mechanics and seismic engineering. Overall, the dissertation provides a unified theoretical and methodological framework for the optimal control of sweeping processes, contributing new insights to nonsmooth analysis, variational inequalities, and control theory.1 0Item Restricted Collisional and quantum effects in plasmas relevant to magnetic confinement fusion(Saudi Digital Library, 2025) ALHARBI, Abdulrahman Saad; MINEA, Tiberiu; SCHIESKO, LoïcThis thesis investigates collisional and quantum effects in plasmas under conditions encountered in magnetic confinement fusion devices. Resonant charge-exchange collisions are first analyzed through a collision operator constructed from the Boltzmann equation, which shows that the charge-exchange mean free path acts as a characteristic length scale modifying ion dynamics and dispersion and predicts conditions where coupling to the field drives an instability. The second class of collisions examined is Coulomb collisions, for which the analysis centers on the Coulomb singularity problem. The divergence of the momentum transfer cross section in classical scattering theory is revisited, and the ad hoc introduction of a minimum cutoff through large-angle scattering is examined. At high temperatures, it is shown within the Born approximation that the minimum cutoff becomes the de Broglie wavelength, which yields a modified Coulomb logarithm derived without heuristic assumptions. Because the separation of scales between classical and quantum minimum cutoffs introduces a temperature constraint in which the de Broglie wavelength has a physical meaning microscopically, a quantum kinetic description is developed to investigate this high-temperature regime from a fully quantum perspective. The N-body Schrödinger equation is reduced under the weak-coupling approximation and reformulated in phase space using the Wigner formalism, with the resulting single-particle kinetic equation closed self-consistently with the Poisson equation, yielding a mean-field model to investigate the collective electronic response at short range. Its application reveals a high-temperature quantum regime from which a short-range potential incorporating quantum screening and diffraction emerges. The short-range potential alters electron-electron and electron-ion scattering, and under temperatures relevant for tokamaks, leads to a differential cross section that departs from the Rutherford form. The corresponding momentum transfer cross section and Coulomb logarithm are revisited in light of these findings. The thesis thereby develops a theoretical description of collisional and quantum effects across plasma conditions, encompassing classical resonant charge exchange in partially ionized regimes and the quantum treatment of Coulomb interactions in high-temperature fully ionized regimes.7 0Item Restricted Enhancing Ethical Practices in Saudi Arabia: Improving the Protection of Human Subjects' Rights in Medical Research(Saudi Digital Library, 2024) AlMadaney, May; Biller-Andorno, Nikola; Andorno, Roberto; Fässler, MargritThis research dissertation investigates the ethical landscape of medical research in Saudi Arabia, with a specific focus on enhancing ethical practices and improving the protection of human subjects' rights. Through a comprehensive comparative analysis of international and national guidelines, the study identifies areas of convergence and divergence, offering a nuanced understanding of the ethical framework within the Saudi Arabian research environment. Additionally, the research examines the current procedures related to informed consent in human subject research, highlighting opportunities for improvement and the implementation of best practices. By addressing the perceptions of Institutional Review Board (IRB) members and their implications for protecting human subjects' rights, the study contributes to a deeper understanding of the challenges and opportunities in ensuring the welfare and rights of research participants. Furthermore, the development and validation of a tool to assess researchers' knowledge and attitudes toward research ethics education and the protection of human subjects' rights represent a proactive step towards promoting a culture of ethical awareness and responsibility among researchers. The findings and recommendations presented in this dissertation have significant implications for advancing ethical practices in Saudi Arabia and improving the protection of human subjects' rights in medical research, both within the local context and with broader relevance to international research ethics. The dissertation provides valuable insights into the ethical considerations and legal frameworks governing medical research in Saudi Arabia and identifies areas for improvement in the protection of human subjects' rights. The recommendations presented in the dissertation have important implications for advancing ethical practices in Saudi Arabia and improving the protection of human subjects' rights in medical research. By addressing these issues, the dissertation has the potential to contribute to the development of more robust ethical guidelines and practices in medical research, ultimately leading to better protection of human subjects' rights and improved healthcare outcomes.15 0Item Restricted Design and validation studies of the FCC-ee positron source : from advanced simulations to proof-of-principle experiments at PSI(Saudi Digital Library, 2026) Alharthi, Fahad Abdullah; Chaikovska, IrynaDriven by the High-Energy Physics (HEP) community's interest in precision studies of the Standard Model (SM), CERN has proposed the Future Circular Collider electron–positron (FCC-ee) as a next-generation collider. The FCC-ee is designed to operate at multiple center-of-mass energies with unprecedented luminosity. A crucial component in reaching this luminosity is the design of a high-intensity, low-emittance positron source. Designing such a source is inherently complex, involving multiple and coupled subsystems: the electron driver beam, the production target, the downstream capture section and positron linac, and the damping ring. This thesis focuses on designing and optimizing the FCC-ee positron source, from the production target to the end of the capture section, which are the most critical stages. The challenges associated with each subsystem are addressed. A dedicated simulation framework was developed by using the Geant4 and RF-Track codes and validated through a series of experimental measurements at the SuperKEKB positron source, and benchmarked against widely used simulation tools (EGS5, ASTRA, GPT). The framework, experimental layout, and benchmarking results are presented, establishing a solid foundation for designing and optimizing a high-intensity positron source for FCC-ee. The proposed layout and optimized design of the FCC-ee positron source are discussed. An alternative positron source scheme based on the use of lattice coherent effects in oriented crystals is proposed and studied. A physics design for this crystal-based positron source is developed, and its application to the FCC-ee and in the PSI Positron Production (P³) experiment is also explored. In addition, an irradiation campaign was conducted at the MAin MIcrotron (MAMI) to study irradiation-induced damage in crystal targets and to commission a thermal diagnostics setup for measuring irradiation-induced heating. The experiment layout, as well as the measurement results, are discussed in detail.1 0Item Restricted Exploring the Impact of Cybersecurity Incidents on Hotel Operations and Reputation in Saudi Arabia(Saudi Digital Library, 2025) Alasiri, Abdullah; Khurdi, Ruby BakshiThe hospitality industry continues to integrate various technologies to improve guests’ satisfaction and optimize organizational performance. However, this reliance also poses a cybersecurity threat to hotels according to Al Hamli and Sobaih (2023). The expansion of the tourism and hospitality sectors within Saudi Arabia under vision 2030 also serves to explain the increased vulnerability to cyber threats. Statement of the Problem The hotel industry is among the most vulnerable to cyber threats because of the kind of information that it processes. A cyber security attack can hinder business activities in a hotel and negatively affect the organization’s reputation, resulting in considerable losses and low customer confidence (Almaiah et al., 2022). The purpose of this research is to examine the effects of such occurrences on the hotels’ business in Saudi Arabia.1 0