Saudi Cultural Missions Theses & Dissertations
Permanent URI for this communityhttps://drepo.sdl.edu.sa/handle/20.500.14154/10
Browse
10533 results
Search Results
Item Restricted Blockchain-Based Platform for Managing Joint Ownership in Real Estate (ReJOM)(Saudi Digital Library, 2026) Almalki, Mohanad; Hussain, FarookhReal estate joint ownership allows multiple investors to pool capital, share risks and access properties that may be difficult to purchase individually. However, managing these arrangements transparently and consistently across key stages of the joint ownership lifecycle remains challenging. Joint ownership arrangements rely on personal relationships and centralised record-keeping. Blockchain technology provides a decentralised, tamper-evident ledger that can record time-stamped actions. However, existing work provides limited and fragmented support for lifecycle management of joint ownership groups across these stages. The main objective of this research is to design, implement and evaluate a blockchain-based platform that supports lifecycle management of real estate joint ownership groups using smart contracts. The platform uses a document-weighted Trust Score to assess participant reliability before group entry. Smart contracts are used to govern joint ownership groups and support automated enforcement of predefined rules with key actions recorded on the blockchain to provide an auditable and tamper-evident history. The platform is implemented as a proof-of-concept prototype that uses Ethereum smart contracts, a web-based application and MetaMask integration to manage user wallets and transactions. The scope is limited to on-chain governance and auditability and does not include off-chain legal transfer processes or physical asset liquidation.10 0Item Restricted Empirical Investigations On Determinants Of The UK Stock Market(Saudi Digital Library, 2025) Nahi, Shada; Bissoondeeal, RakeshThis thesis examines the determinants of the UK stock market and their interactions under periods of stress. It explores three key factors influencing stock price performance. In particular, these factors are macroeconomic variables, firms’ Environmental, Social, and Governance (ESG) ratings, and Bitcoin bubbles. The research is structured into three main objectives. First, it investigates the causal relationship between macroeconomic indicators and stock prices by employing both standard and quantile Granger causality methods to capture the variation of sectoral and economic conditions. Second, it analyzes the impact of firms’ ESG ratings on stock price crash risk using a fixed effects model to examine whether ESG factors contribute to market stability and focus on prior and post COVID-19 periods. The last objective explores the financial contagion effects of Bitcoin bubbles on stock market volatility by detecting bubble periods using the GSADF test and analysing their impact on sectoral volatility using the GARCH-X model. The findings reveal significant macroeconomic influences on stock prices with sectoral differences in causality patterns. The quantile Granger causality approach provides deeper knowledge of bidirectional relationships under varying economic conditions. ESG ratings exhibit mixed effects on stock price crash risk before and during the COVID-19 crisis and reveal sectoral variations. Bitcoin bubbles reported varying impacts on stock market volatility. Specifically, the relationship had changed from a hedging role in pre-pandemic periods to a volatility factor during crises. These results have important implications for investors, policymakers, and financial analysts. Further, it highlights the necessity for adaptive investment strategies, regulatory considerations, and risk management approaches focusing on sector-specific and economic conditions.8 0Item Restricted Statistical Methods Used to Predict Progression in Parkinson’s Disease: A Critical Review(Saudi Digital Library, 2026) Almohammadi, Abdulrahman Ghuwayzi; Stelios, GeorgiouThis thesis critically reviews the statistical methods used to predict progression in Parkinson’s disease, with emphasis on how different model families match the mathematical structure of the outcomes they are de- signed to predict. The review is organised as a structured narrative synthesis of a curated corpus of 50 references spanning Parkinson’s disease prognostic studies, methodological reviews, and reporting or ap- praisal guidance. Across the literature, progression is represented through continuous symptom trajectories, fixed-horizon binary outcomes, milestone-based time-to-event endpoints, multidomain deterioration, latent severity processes, and multimodal subtype or risk-classification tasks. These outcome structures motivate different statistical approaches, including regression and mixed-effects models, Cox and time-dependent sur- vival models, joint longitudinal-survival models, multivariate and latent-variable frameworks, and machine- learning systems. The central conclusion is that no single modelling family is universally best. Rather, methodological appro- priateness depends on the structure of the response variable, the role of repeated measures, the presence of censoring, dropout, or missingness, the required level of interpretability, and the intended clinical or research use of the prediction. The review also shows that many published prognostic models remain limited by weak handling of missing data, incomplete calibration assessment, inconsistent external validation, and inadequate reporting transparency. Its main contribution is therefore not simply to catalogue existing methods, but to clarify how model choice in Parkinson’s disease progression prediction should be driven by statistical structure and methodological maturity rather than by algorithmic novelty alone. The thesis therefore con- tributes a decision-oriented statistical framework for matching Parkinson’s disease progression outcomes to appropriate model families, with explicit attention to assumptions, repeated-measures structure, censoring, missingness, validation, calibration, interpretability, and intended use.10 0Item Restricted The Development of Receptive and Productive Knowledge of Idiomatic Phrasal Expressions in Saudi EFL Learners: A Multi-Phase, Multi-Modal Corpus Study(Saudi Digital Library, 2026) Alsoghayer, Huda Mansour; Anne, O’KeeffeWhile corpus linguistics has revolutionized vocabulary teaching, idiomatic phrasal expressions (IPEs) remain underrepresented in Saudi mainstream syllabi. Existing studies often lack longitudinal scope, multimodal analysis, or robust corpus design, leaving critical questions unanswered about how idiomatic competence develops across time, tasks, and instructional conditions. This dissertation investigates how Saudi EFL learners acquire, use, and retain idiomatic phrasal expressions (IPEs) across three phases: baseline, intervention, and retention, while examining modality effects (writing versus speaking). The study adopts a longitudinal, mixed-methods design, and draws on the Saudi Female English Corpus (SFEC), a purpose-built learner corpus of approximately 100,000 words, comprising 300 spoken and written texts produced by 60 Saudi female university learners (experimental = 30; control = 30). Productive idiomatic use was analyzed using Martinez and Schmitt’s Phrasal Expressions List (2012), organized into five frequency bands (B1–B5), alongside a receptive idiomatic expressions test. Quantitative analyses examined idiomatic density, lexical variety, frequency-band distribution, and receptive–productive alignment, while qualitative analyses explored pragmatic functions, syntactic patterning, and cross-linguistic influence. Baseline findings revealed a pronounced receptive–productive gap, with learners recognizing high-frequency IPEs (Bands 1–2) but rarely producing them accurately. Following a corpus-informed, explicit instructional intervention, the experimental group demonstrated substantial gains in productive idiomatic use, particularly in writing, where idiomatic density increased by 129% and expanded into Bands 3–5. Speaking gains were more modest (≈19.5%) but stylistically meaningful, involving discourse markers and stance expressions. Retention analysis indicated partial attrition two months post-intervention, with Band 3 IPEs showing the strongest durability. Importantly, non-canonical and L1-influenced forms produced by the experimental group are interpreted as developmental risk-taking, reflecting deeper conceptual engagement and emerging figurative awareness rather than simple error, whereas the control group’s largely accurate output reflects more conservative, low-risk strategies with limited stylistic expansion. Pedagogically, the findings support corpus-informed, frequency-sensitive IPEs instruction grounded in Data-Driven Learning (DDL), highlighting a reciprocal relationship in which learner corpora function as positive pedagogical exemplars while simultaneously informing corpus-based instructional design.2 0Item Embargo The Dissolution and Fabrication of Hybrid Cellulose- Protein composites in Ionic Liquid of 1- ethyl-3-methyl- imidazolium acetate [Emim][OAc](Saudi Digital Library, 2026) Alqarni, Samiah; Hine, Peter; Ries, MichaelThe increasing demand for sustainable and environmentally friendly materials has accelerated research into renewable bio-based composites as alternatives to conventional petroleum-derived systems. This thesis investigates the dissolution behaviour, structural transformation, and fabrication of all-hybrid cellulose composites based on cellulose–protein systems using hemp–keratin and flax–silk hybrid yarns and woven fabrics. The ionic liquid 1-ethyl-3-methylimidazolium acetate ([Emim][OAc]) was employed as a solvent to achieve controlled partial dissolution, enabling the formation of regenerated matrix phases while preserving part of the original fibrous reinforcement structure. The dissolution behaviour of hemp–keratin and flax–silk hybrid yarns was systematically studied as a function of temperature and time using optical microscopy (OM), wide-angle X-ray diffraction (XRD), gravimetric analysis, and mechanical testing. The results demonstrated that dissolution strongly depends on both processing temperature and dissolution time, with cellulose dissolving more rapidly than protein components. In hemp–keratin systems, cellulose dissolution occurred at lower temperatures, while keratin required significantly higher energy due to the presence of disulfide bonds. Activation energies determined using time–temperature superposition (TTS) analysis and Arrhenius modelling were 55 ± 5 kJ/mol for hemp cellulose and 111 ± 9 kJ/mol for wool keratin. For flax–silk hybrid yarns, optical microscopy revealed distinct dissolution mechanisms for each component. Cellulose dissolved progressively from the outer surface inward, forming a coagulated matrix layer that gradually restricted further ionic liquid penetration. In contrast, silk dissolved individually from the outer surfaces of each filament, initially filling internal gaps before merging with the cellulose matrix at later stages of dissolution. XRD analysis confirmed the transformation of cellulose I into cellulose II and amorphous cellulose during dissolution and regeneration. The raw flax–silk yarn contained approximately 57 % cellulose I, which decreased to 8 % after treatment at 50 °C for 2 hours, while cellulose II increased to 23 %. Evidence of overlapping diffraction peaks indicated intermolecular interactions and partial phase mixing between cellulose and silk. TTS analysis demonstrated Arrhenius-type behaviour for both components, yielding activation energies of 95 ± 5 kJ/mol for flax cellulose and 76 ± 9 kJ/mol for silk. Mechanical analysis yielded activation energies of 73–82 kJ/mol, consistent with structural observations. Following the yarn-scale studies, all-hybrid woven composites were fabricated from hemp–keratin and flax–silk fabrics using two processing routes: an excess ionic liquid bath process and a batch process. Mechanical testing showed that Young’s modulus and tensile strength initially increased with dissolution temperature due to improved interfacial bonding and matrix formation, before decreasing at higher temperatures because of excessive dissolution of the reinforcing fibrous network. This behaviour confirmed the existence of a preformed stage during composite consolidation. The incorporation of an interlayer cellulose film significantly improved peel strength and interfacial adhesion by promoting the formation of a continuous regenerated matrix at the interface, although increased matrix content reduced stiffness under some conditions. Cellulose–keratin composites consistently exhibited higher stiffness than cellulose–silk composites, while differences between warp and weft directions highlighted the influence of fabric architecture, yarn alignment, and crimp on composite performance. TTS analysis of woven composites further confirmed Arrhenius-type dissolution behaviour at the fabric scale and produced an activation energy of 16 ± 3 kJ/mol, providing quantitative insight into the dissolution kinetics at the fabric scale. The relatively low activation energy compared to individual hybrid yarn systems suggests that the woven architecture and partial dissolution–consolidation mechanism facilitate solvent transport and matrix formation during composite processing. Overall, this thesis demonstrates that [Emim][OAc] is an effective solvent for producing sustainable all-hybrid cellulose composites through controlled partial dissolution of cellulose–protein fibre systems. The work provides new insight into dissolution kinetics, structural evolution, interfacial interactions, and structure–property relationships in hybrid biopolymer composites, contributing to the development of high-performance renewable materials for sustainable engineering applications.6 0Item Restricted Phage-based deodorant : Isolation and characterisation of bacteriophages targeting odour-generating Staphylococcus species and expression of recombinant phage endolysins(Saudi Digital Library, 2026) Alahmadi, Abdullah; Galyov, EdouardAbstract Human axillary malodour arises when secretions from sebaceous, eccrine, and apocrine glands are biotransformed by skin bacteria into volatile fatty acids, thioalcohols, and steroid derivatives. Broad-spectrum preservatives used in deodorants can suppress odour but disrupt skin homeostasis. A selective strategy is to deploy lytic bacteriophages or their phage-encoded, peptidoglycan-degrading enzymes (endolysins) against the principal odour-driving taxa, notably Staphylococcus hominis. A panel of 15 novel phages active against odour-associated staphylococci was assembled, with detailed characterisation focused on a lead lytic isolate, AA001 Staphylococcus phage, recovered on S. hominis. AA001 displayed a narrow plaque host range yet encoded an unusual two-lysin lysis cassette upstream of a holin. The two endolysins named AaeA (CHAP-SH3b, 256 aa) and AaeB (CHAP/NlpC/P60–SH3b, 320 aa); AaeA carries the predicted catalytic triad Cys134/His140/Asn143 - 144, and AaeB Cys140/His154/Asn160. were cloned and expressed as N-terminal GST fusions (pLEICS 14) and in a T7/His system. fusions partitioned to inclusion bodies but retained activity following 2 M urea solubilisation. A Tris/NaCl/Triton shifted expression into the soluble fraction: SDS PAGE of clarified lysates consistently showed a three-band signature fusion (~56/62 kDa), tag-free endolysin (~30/36 kDa), and free GST (~26 kDa). Glutathione chromatography enriched the fusion, whereas tag-free species predominated in flow through/washes; anti-GST Westerns reported GST-bearing bands only. Functionally, both the soluble supernatant and glutathione eluates exhibited lytic activity on staphylococci, and broth killing (OD₆₀₀) confirmed rapid, treatment-dependent inhibition with the potency order AaeA+AaeB cocktail > AaeB ≥ AaeA ≫ phage AA001 > control for S. hominis; the same ordering held for S. aureus with a smaller dynamic range. In the T7 system, recombinant lysates were likewise soluble and active, whereas native Ni-NTA capture of the ~30/36 kDa species was inefficient, consistent with tag processing or masking. Collectively, these results establish soluble, highly active endolysins from a staphylococcal phage, demonstrate broader enzyme activity than the parent phage’s plaque host range, and support their potential as selective, microbiome-sparing actives for deodorant-adjacent applications.8 0Item Restricted The Potential of Animated Videos In The Development of English Tense-Aspect Usage For Saudi EFL Learners(Saudi Digital Library, 2026) Alshahrani, Sarah; Alshahrani, SarahLearning to use the English tense-aspect (TA) system appropriately appears to be one of the greatest challenges that EFL students face (Celce-Murcia et al., 1999, p. 131), with Saudi learners experiencing particular difficulty due to fundamental typological differences between Arabic and English temporal-aspectual systems. While explicit instruction raises metalinguistic awareness, it frequently fails to produce mastery of complex TA structures (Ellis, 2015). This study investigates whether multimedia-based incidental learning through animated videos offers a more effective alternative to traditional text-based instruction, and examines whether visual input enhancement, specifically, colour-coded caption highlighting, increases learning effectiveness. Sixty female intermediate Saudi EFL learners were assigned to three instructional conditions and were taught usage of three TAs: Simple Past, Present Perfect, and Present Perfect Progressive. The Control Group (N=20) received traditional text-only instruction through written dialogues. The Non-Enhanced Treatment Group (N=20) watched identical animated videos with standard black-font captions without visual enhancement. The Enhanced Treatment Group (N=20) viewed 2D character-based animated videos with red-font colour-coded captions highlighting target TA items. The animations presented TA forms through meaningful character dialogue and narrative contexts but did not include explicit visual illustrations of temporal concepts such as timelines or temporal markers. Learners' knowledge was assessed before the intervention and immediately post-intervention through four task types: forced-choice judgments, verb selections, cloze completion tasks, and error correction exercises. Learner attitudes were measured through post-treatment questionnaires assessing enjoyment, anxiety, and perceived usefulness. Generalised Linear Mixed-Effects modelling revealed unexpected patterns contradicting theoretical predictions. The Non-Enhanced Treatment Group demonstrated the strongest and most statistically significant improvement, while the Enhanced Treatment Group showed modest but significant gains, and the Control Group displayed negligible improvement. Paradoxically, attitude data revealed an opposite relationship with learning outcomes. The Control group reported highest enjoyment, lowest anxiety, and strongest perceived usefulness despite minimal learning gains. Conversely, the non-enhanced group, which learned most, reported lowest enjoyment, highest anxiety, and lowest perceived usefulness. The Enhanced group exhibited intermediate attitudes between these extremes. This research advances understanding of multimedia-based grammar instruction for Saudi EFL learners while highlighting the importance of balancing cognitive outcomes with affective dimensions in materials development and instructional implementation.5 0Item Restricted Sustainability and Accountability in Debt Finance: A Comparative Analysis of Green Bonds and Sukuk(Saudi Digital Library, 2026) Merdad, Roya; Schilling De Carvalho, PedroThis dissertation examines how ICMA Green Bonds and Sukuk address similar sustainability and accountability concerns in debt finance through different institutional and governance mechanisms. It compares the governance architecture of both instruments, assesses how these mechanisms operate in practice, and considers what lessons each framework can offer the other to improve governance outcomes. The analysis demonstrates that Sukuk embed sustainability and accountability through asset-backing, Shariah compliance and supervisory oversight, while ICMA Green Bonds rely primarily on use-of-proceeds requirements, disclosure, reporting and market discipline. In practice, ICMA Green Bonds benefit from scalability, market standardisation and significant capital mobilisation, but face challenges including greenwashing, information asymmetry and limited binding enforcement. Sukuk provide stronger pre-issuance oversight and a closer connection between financing and real economic activity, but their effectiveness is weakened by fragmentation across jurisdictions, differing interpretations of Shariah principles and uncertainty regarding consistent post-issuance monitoring. The dissertation therefore concludes that neither framework provides a universally superior model of sustainable debt finance. Instead, each offers distinct strengths that can inform improvements to the other. ICMA Green Bonds could benefit from stronger oversight, asset-backing and legally enforceable disclosure, while Sukuk could benefit from greater standardisation and consistency across jurisdictions. Both frameworks would also benefit from stronger post-issuance monitoring to ensure that governance commitments remain effective throughout the life cycle of the instruments.4 0Item Restricted SERVANT LEADERSHIP PERCEPTION AND EMPLOYEE OUTCOMES: THE MEDIATING ROLE OF JOB CRAFTING AND THE MODERATING EFFECT OF SEX(Saudi Digital Library, 2026) Shalan, Haifa; Richard, Klein; Xiaoyun, CaoThis study examined how perceived servant leadership influences faculty members’ outcomes, specifically work engagement, strain, and performance (examined across three dimensions: in-role performance, organizational citizenship behavior toward individuals [OCBI], and organizational citizenship behavior toward the organization [OCBO]), through the mediating role of approach and avoidance job crafting, and whether this process differs by sex. Data were collected from 160 faculty members at public universities in Saudi Arabia using a two-wave survey design. Structural equation modeling (SEM), including confirmatory factor analysis (CFA) and parcel-based measurement model evaluation, was used to assess the measurement model and test direct relationships. Regression-based PROCESS analyses with bootstrapped confidence intervals were then conducted to examine indirect effects (Model 4) and moderation effects (Model 1). Results showed that servant leadership was marginally positively related to approach job crafting but not to avoidance job crafting. Approach job crafting was positively associated with in-role performance and organizational citizenship behavior toward individuals, while avoidance job crafting was negatively related to organizational citizenship behavior toward the organization. Mediation analyses revealed that Approach job crafting showed significant indirect effects linking servant leadership to in-role performance and OCBI; the remaining direct effects were nonsignificant, suggesting a pattern consistent with full mediation. Avoidance job crafting did not mediate any of the examined relationships. Unexpectedly, servant leadership was positively associated with strain, suggesting that supportive leadership may have more complex implications in highly structured academic settings, while also significantly increasing work engagement but showing no significant relationship with performance outcomes, including in-role performance, OCBI, and OCBO. Additionally, sex did not moderate the relationship between servant leadership and either type of job crafting. These findings contribute to the literature by highlighting the selective role of job crafting in linking servant leadership to performance, with limited effects on engagement and strain.3 0Item Restricted Mathematical Model for Simulating Ice Shelf Breakup(Saudi Digital Library, 2026) Alshahrani, Faraj; Mike, Meylan; Ben, WilksOcean waves strongly influence the mechanical stability, fragmentation, and even- tual disintegration of floating ice shelves, which are floating extensions of continental ice sheets that form where glacial ice moves from land into the ocean. Understanding these hydroelastic processes is crucial for improving models of ice-shelf breakup and their contribution to global sea-level rise. This thesis develops analytical and nu- merical mathematical models to study wave-ice interactions and sequential ice-shelf breakup. This thesis makes three novel contributions to the hydroelastic modelling of ice shelves. The first novel contribution analyses the interaction between water waves and multiple ice-shelf fragments in front of a semi-infinite ice sheet. Hydrodynamics are described by shallow-water theory and ice elasticity by Kirchhoff–Love plate theory, resulting in a multiple-scattering problem solved in the frequency domain with the transfer matrix method. An energy conservation identity validates the numerics, and transient responses to wave packets are built from vs. This provides a basic framework for modelling wave-induced ice-shelf fragmentation. The second novel contribution presents a time-domain model for an ice shelf interacting with waves in a finite domain containing open water and ice-covered regions. The Shallow-water equations are coupled with the Kirchhoff-Love plate theory, leading to a nonlinear matrix eigenvalue problem for the natural modes and frequencies of the coupled system. These modes are used in a spectral method to reconstruct transient responses to wave forcing. Simulations show how incident wave packets excite multiple structural modes and create complex interference patterns through internal reflections. The third novel contribution introduces a framework to simulate the sequential breakup of a wave-forced ice shelf, again coupling shallow-water hydrodynamics with Kirchhoff–Love plate theory. Fragmentation is triggered by a critical threshold criterion that allows progressive cracking into multiple fragments. The formulation leads to a nonlinear eigenvalue problem whose complexity grows as new cracks form. Simulations illustrate the breakup sequence and examine the effects of clamped, free- edge, and simply supported boundary conditions. The results are checked using energy conservation and time-step convergence. Overall, the thesis establishes mathematical and numerical frameworks for wave- induced ice-shelf vibrations and fragmentation, progressively incorporating wave scattering, transient hydroelastic response, and sequential breakup. This work sup- ports future extensions to unbounded domains and higher-dimensional geometries to improve predictive models of ice-shelf disintegration.11 0