SACM - United Kingdom
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Item Restricted Investigating Nucleophilic Reactions of Organic Thin Films at the Molecular Scale Using Chemical Force Microscopy(University of Sheffield, 2025) Samman, Bayan; Leggett, GrahamSurface reactions are central to many scientific and technological processes, including industrial catalysis, environmental remediation, and energy conversion. A detailed understanding of interfacial interactions at the nanoscale requires insight into the chemical, physical, and mechanical processes that govern surface behaviour. This thesis investigates the chemical interactions of functional organic thin films with defined surface terminations using chemically modified atomic force microscopy (AFM) probes in chemical force microscopy (CFM). The work addresses two objectives: first, to examine nucleophile–electrophile interactions and the influence of solvent media; and second, to investigate the tribological aspects of surface reaction kinetics. Chapter 3 uses force–distance measurements to quantify adhesion forces and elucidate probe–surface interactions. Chapter 4 uses lateral force microscopy (LFM), also known as friction force microscopy (FFM), to examine reaction-related frictional behaviour. Two hypotheses are tested: that CFM can measure interaction forces between nucleophiles and electron-deficient carbon centers, and that CFM can probe bond-formation processes during nucleophilic reactions. More than 64 systems, including silane- and thiol-based self-assembled monolayers, were examined. The results show that adhesion and friction forces increase with the mole fraction of reactive functional groups. Amino-functionalised surfaces exhibit pronounced time-dependent evolution, consistent with progressive interfacial chemical transformation. Distinct contributions from hydrogen bonding, van der Waals interactions, and covalent bond formation are identified, with adhesion enhanced in nonpolar environments. Notably, the nucleophilic-electrophilic reaction between the tip and the sample occurred within ~14 min.15 0Item Restricted Heterostructure of NiCo2O4@Ni-CeO2 for High Current Density Water Splitting(Saudi Digital Library, 2025) Algethami, Aljawharah; Jalebi, MojtabaThis study investigates the synthesis and characterization of NiCo₂O₄@Ni–CeO₂ heterostructures for enhanced electrolysis applications. Seven different electrodeposition approaches were systematically evaluated, including stepwise and co-electrodeposition methods, to understand the relationship between synthesis methodology and electrochemical performance. The research addresses the critical need for cost-effective, earth-abundant electrocatalysts to replace expensive noble metals in water splitting technology for green hydrogen production. Our findings demonstrate that synthesis approach dramatically influences catalytic performance. Sample S7, synthesized via co-electrodeposition, achieved exceptional oxygen evolution reaction (OER) performance with an overpotential of 297 mV at 20 mA cm⁻², significantly outperforming individual components and demonstrating competitive performance against literature benchmarks. However, this sample showed poor hydrogen evolution reaction (HER) activity (404 mV at -10 mA cm⁻²), highlighting the inherent challenges in bifunctional catalyst design. Conversely, samples S2 and S4 exhibited excellent HER performance (136 mV each) but relatively poor OER activity. Comprehensive characterization using scanning electron microscopy, Raman spectroscopy, and electrochemical impedance spectroscopy revealed that co-electrodeposition creates uniform heterostructures with enhanced interfacial contact and optimal charge transfer properties (Rct = 1.5 Ω). Surface wettability analysis confirmed superhydrophilic properties (0° contact angle) for the co-electrodeposited sample, facilitating improved electrolyte-catalyst interaction. Light- enhanced measurements demonstrated photocatalytic enhancement across all samples, indicating potential for solar-driven applications. Overall water splitting analysis revealed that sample S4 achieved the lowest total cell voltage (1.727 V), emphasizing that balanced bifunctional performance is more critical than excellence in single half-reactions. The results highlight fundamental trade-offs in heterostructured catalyst design, where optimization for one reaction often compromises performance in the other. This work provides valuable insights into structure-performance relationships and demonstrates the potential of electrodeposited NiCo₂O₄@Ni–CeO₂ heterostructures for practical water splitting applications.8 0Item Restricted Theoretical investigation for electrochemical CO2 reduction on silver and tin surfaces(Saudi Digital Library, 2026) Alsuwayni, Bandar; Lambert, Colin; Wu, QingqingThis thesis investigates strategies for enhancing electrochemical carbon dioxide (CO2) reduction through a systematic study of catalyst surface modification. Particular attention is given to silver (Ag) and tin (Sn) as base materials, with a focus on the role of dopants in improving catalytic activity and selectivity. In CO2 electroreduction, the nature and stability of reaction intermediates are critical in determining product distribution. In particular, *COOH is widely recognised as the key intermediate in the formation of carbon monoxide, whereas *OCHO governs the pathway towards formic acid. The competition between these intermediates for active sites plays a decisive role in controlling catalytic selectivity. The study employs density functional theory (DFT) calculations using the Vienna Ab initio Simulation Package (VASP), with the generalised gradient approximation (GGA) to analyse the geometric and electronic properties of the investigated systems. The results provide detailed insights into how targeted doping strategies can be used to optimise catalyst performance. For Ag-based systems, silver and gold clusters supported on the Ag (111) surface are examined to evaluate the effects of cluster composition and size. The presence of these clusters significantly alters the reaction energetics associated with *COOH formation. Smaller Ag clusters exhibit slightly greater reductions in energy barriers than larger ones, whereas larger Au clusters demonstrate superior performance compared with their smaller counterparts. This highlights a distinct size-dependent effect that varies with cluster composition. For Sn-based systems, bismuth (Bi) doping is investigated in both adsorbed and substitutional configurations relative to pristine Sn surfaces. Bi incorporation enhances catalytic activity and promotes selectivity towards formate formation under both gas-phase and solvated conditions. Among the configurations studied, Bi atoms adsorbed on the Sn surface yield the most favourable energetic profiles, characterised by lower reaction barriers. However, achieving precise control over the adsorption of competing intermediates (*COOH and *OCHO) remains a key challenge for further improving selectivity. Overall, this work demonstrates that rational surface modification through doping provides an effective strategy for tuning activity and selectivity in CO2 electroreduction catalysts.14 0Item Restricted MBA Capstone Retrieval Essay(Saudi Digital Library, 2026) Abuzaid, Khaled; Alshoaibi, BayanThis essay reflects on how Khaled Abuzaid's experience at London Business School shaped his professional and personal network. Drawing on his background in Saudi Aramco and his pivot toward venture capital, he traces how cohort proximity, diverse classmates, and shared projects built relationships deeper than the classroom alone could produce. The cohort's global breadth enriched intellectual discourse and proved decisive in his career trajectory, from securing a BCG internship to landing a corporate VC role. He frames the network not as a transactional asset but as a long-term foundation for trusted collaboration, potential co-investment, and possibly building something together down the line.3 0Item Restricted Supporting Fifth Grade Students' Socially Shared Regulated Learning with E-Tools in Collaborative Scientific Inquiry: A Design-Based Research Study(Saudi Digital Library, 2026) Alajaji, Deema; Webb, Mary; Healy, Lulu; Hadwen-Bennett, AlexContemporary science curricula increasingly encourage inquiry-based tasks within computer-supported collaborative learning environments (CSCL) to develop both conceptual understanding and lifelong learning skills. Within these contexts, socially shared regulation of learning (SSRL) enables students to coordinate efforts, learn from one another, and complete collaborative tasks effectively. Despite SSRL's importance for group coordination and task success, younger students often struggle with shared regulation and display unequal participation in regulatory processes. Limited research has focused on supporting SSRL amongst primary-aged learners through digital means. Additionally, existing research often focuses on individual cognitive regulation, overlooking the broader, multifaceted nature of SSRL, which encompasses cognitive, behavioural, motivational, and socioemotional dimensions. Furthermore, whilst several models explain how SSRL occurs, frameworks for supporting SSRL remain scarce. This study employed design-based research (DBR) methodology to explore how e-tools can support SSRL amongst fifth-grade students (aged 10–11) engaged in scientific inquiry within CSCL environments. Through three iterative design cycles, I developed and refined digital tools to support SSRL, guided by three research questions examining whether e-tools supported targeted SSRL phases, how students regulated their learning, and students' perceptions of the tools' influence. Findings from each cycle helped identify design challenges and affordances and informed design decisions for the subsequent design cycle. Data collection in each cycle involved video recordings and classroom observations of two groups, students' input within the e-tools, and post-task focus groups to explore their perceptions. I qualitatively analysed all collected data through multiple methods. Video recordings and observational data were transcribed and analysed using a multi-level analysis method based on the COPES model of SSRL to assess whether e-tools supported targeted stages of SSRL. Students' input within the e-tools was analysed and categorised 4 based on the phases of SSRL they supported and their alignment with e-tool objectives. Focus group transcriptions underwent thematic analysis to understand students' experiences and perceptions of the e-tools. Findings indicate that the effectiveness of SSRL-support e-tools depends on multiple factors, which are the design of the e-tools and the SSRL processes they support, task complexity and structure, prompt design, timing of integration into classroom practice, and teacher guidance. E-tools were most effective when embedded within complex, open-ended tasks that demanded sustained SSRL. Students responded more meaningfully when the use and timing of e-tools were flexible and aligned with their learning needs, rather than fixed at predetermined intervals (start, middle, and end of task). Concise prompts that focused on specific SSRL processes, such as goal setting, recursive evaluation of goals, and the externalisation of emotions, promoted engagement with the e-tools, whereas overly detailed or repetitive prompts led to disengagement and negative perceptions. Integrating planning, evaluation, and socioemotional regulation into a single digital platform, as trialled in the third design cycle, supported the recursive nature of SSRL and enhanced students’ externalisation of SSRL, students’ perceptions, and engagement. Additionally, providing space for socioemotional expression enabled students to externalise negative emotions; however, in instances where this was insufficient to resolve challenges, teacher intervention in facilitating SE e-tools played a critical role. Overall, teacher support was essential in modelling goal setting, guiding constructive emotional expression, encouraging engagement with the e-tools, and helping students address challenges that they were unable to resolve independently. This research contributes empirically grounded design principles and a practical model for supporting SSRL in upper primary CSCL contexts, providing guidance for educators, instructional designers, and curriculum developers. Whilst limitations include small sample size and implementation in selective IB schools, the study establishes a foundation for future research in diverse educational settings and the potential integration of generative AI to support student regulatory processes.12 0Item Restricted Investigation of the Performance of Granular Columns in Soft Clay Soil Using Discrete Element Method(Saudi Digital Library, 2026) Almasmoum, Ahmed Ali A; Faramarzi, Asaad; Jefferson, IanGround improvement techniques are essential for enhancing poor ground conditions in construction, particularly in soft soils where low bearing capacity and high compressibility occur. Common methods include reinforcement, material replacement, and chemical stabilization, with Vibro stone columns (VSC) being the most common due to their versatility and ease of construction. VSC design methods were established in the 1970s, but research continues to enhance predictions of the improvements achievable in bearing capacity and settlement behaviour. However, the complexity of soil-column interactions and the behaviour of column materials remain a significant challenge, particularly at particle level. Primary aggregates used in VSC construction are becoming scarce, prompting the use of secondary and recycled aggregates. However, their behaviour within VSCs is not fully understood, necessitating further particle-level research. Numerical continuum modelling, such as the finite element method (FEM), have limitations in capturing particle level behaviour, thus restricting the use of alternative aggregates. This research focuses on the impact of column particle size and shape on VSC performance using the Discrete Element Method (DEM). The study evaluated the effect of particle size distribution and shape on performance after validating the DEM stone column model with published experimental data. Parametric studies were conducted on particle size, particle size distribution (PSD), and shape for different scenarios. In total, 36 DEM scenarios were examined, covering particle size/PSD and particle shape. All results were compared against the validated model to ensure consistent and reliable assessment. The results show that particle size is key for stone column performance, and PSD is also an important factor. PSD affects how the column material behaves during construction and how the improved ground responds under loading. In general, larger particles and a wider PSD improve confinement and increase the overall load-bearing response. Uniform grading can help with constructability and drainage but tends to reduce compaction effectiveness and stability. The PSD study also identified the best non-uniform grading with a higher proportion of larger particles, and this gave better performance than the validated reference case. The layered-column results further show that placing larger particles in the bulging zone can improve load resistance. Thus, this suggests that a mixed columns consisting of two PSD along the length of the column will improve overall performance. The work on Particle shape proved to be the most influential parameter, with a greater effect on performance than particle size. Angular particles develop strong interlock, producing peak axial stresses approximately 67% higher than the validated baseline. Rounded particles, by contrast, suppress interlock and reduce the mechanical response, with peak axial stress falling approximately 13% below the baseline. Rounded aggregates should therefore be avoided in applications requiring high stiffness and effective load transfer. Analysis of idealised particle shapes confirmed that interlock capacity is the dominant performance-controlling mechanism. Blended (mixed-shape) columns responded differently from single-shape configurations which demonstrates the importance of mixture effects and why shape should be assessed rather than assumed from one type. Thus, the effectiveness of stone columns is associated with combinations of particle size, size distribution, and shape. By adjusting the size and shape of these particles, stone columns can be constructed with enhanced effectiveness, stability, and durability. The findings provide a basis for more evidence-led specification and quality control of column aggregates, particularly where secondary or recycled sources are considered. This research advances understanding of particlelevel mechanisms in VSCs and supports more informed, reliable, and efficient ground improvement practice.5 0Item Restricted Well-being-Oriented HRM, Employee Well-being, and Employee Retention: A Mixed-Methods Study in the Saudi ICT Sector(Saudi Digital Library, 2026) Alqatifi, Hussain Yousef; Procter, StephenPurpose: This thesis investigates whether well-being-oriented HRM (WBHRM) practices are associated with employees' intention to stay through the potential contributions of psychological well-being (employee satisfaction), social well-being (perceived organisational support), and physical well-being (emotional exhaustion). It addresses persistent gaps in the HRM, well-being and performance literature, specifically the predominance of organisation-centred HRM perspectives and the narrow conceptualisation of employee well-being that typically reduces it to job satisfaction alone, particularly within the rapidly transforming and highly competitive Saudi information and communications technology (ICT) sector, where national development plans have intensified competition for skilled talent and elevated external mobility. Methods: Guided by Job Demands-Resources (JD-R) theory, this thesis conceptualises WBHRM practices as job resources that are associated with satisfaction, perceived organisational support, emotional exhaustion and employees' intention to stay. The study employed an explanatory sequential mixed‑methods design. A survey of 238 employees across three Saudi ICT companies was analysed with partial least-squares structural equation modelling (PLS-SEM) to test hypothesised paths and importance-performance map analysis (IPMA) to prioritise actionable levers. Subsequently, a nested subsample of 12 survey participants was interviewed to acquire richer insights into the contextual factors influencing employee well-being and turnover intentions. Findings: Quantitative findings indicated that WBHRM practices were positively associated with employee satisfaction and perceived organisational support and negatively associated with emotional exhaustion. However, they showed no direct association with employees' intention to stay. Employee satisfaction and emotional exhaustion jointly accounted for the WBHRM-intention to stay association, whereas perceived organisational support did not operate as a mediator. The IPMA report yielded four key findings: (1) emotional exhaustion was highlighted as highly important yet remains the lowest-performing area; (2) WBHRM practices function as key job resources; (3) job satisfaction is already performing well; and (4) perceived organisational support contributes little to retention decisions. Narratives from the interviews supported these patterns, showing that employees appreciated such supportive practices. However, unclear promotion processes, lagging market compensation, and intensive work demands frequently undermine WBHRM practices' potential benefits, prompting employees to pursue external opportunities despite valuing flexible working arrangements and a supportive work environment. Contributions: This thesis expands the HRM-well-being-performance literature by investigating employee-centred HRM practices (i.e., WBHRM) and integrating three distinct dimensions of employee well-being: satisfaction, perceived organisational support, and emotional exhaustion, through an explanatory sequential mixed-methods design. Although WBHRM practices were linked to lower exhaustion and higher satisfaction, these findings demonstrate that employees still leave if core structural issues, such as unclear or unfair promotion criteria, lag‑market compensation, and job strains and pressures, remain unaddressed. The study offers new insights into rapidly changing labour markets undergoing national transformation and increasing talent competition.20 0Item Restricted The Role of Ethical Leadership in Addressing Gender Equality in Leadership Positions in Saudi Higher Education(Saudi Digital Library, 2026) Qurashi, Abrar; Schröder, HeikeThis study examines the role of ethical leadership in promoting gender equality in leadership positions within Saudi higher education, focusing on King Abdulaziz University as a case study. Using a qualitative exploratory approach, the study draws on thirty-seven semi-structured interviews with men and women in mid- and senior-level leadership roles, supported by secondary data. The findings show that although recent national reforms, particularly Saudi Vision 2030, have expanded women’s participation and strengthened transparency and accountability, gender inequality in leadership remains influenced by organisational practices, sociocultural norms, and structural constraints. The study highlights ethical leadership as an important mechanism for promoting fairness, merit-based decision-making, and organisational legitimacy, while also demonstrating that leadership practices are shaped by cultural and institutional contexts. The research contributes to understanding how ethical leadership can support substantive progress towards gender equality in higher education within reform-driven, non-Western settings, and offers practical insights for policymakers and university leaders seeking to enhance women’s leadership opportunities.5 0Item Restricted Modelling Future Global Renewable Hydrogen Trade under Competitive and Cooperative Market Structures(Saudi Digital Library, 2026) Alanazi, Khalid Fihat B; Hawkes, Adam; Shah, NilayRenewable hydrogen trade is expected to play an important role in achieving deep decarbonisation by linking regions with abundant renewable energy resources to those with high demand and limited domestic supply potential. Despite its importance, significant uncertainty remains regarding the formation of global hydrogen markets, the scale of hydrogen trade, and the distribution of economic benefits among participating regions. This thesis advances knowledge by developing modelling frameworks to analyse global renewable hydrogen trade under three alternative market structures: perfect competition, strategic imperfect competition, and cooperative bargaining. These frameworks integrate renewable hydrogen supply and demand functions to endogenously determine prices, traded volumes, and economic surplus distribution in a fully decarbonised energy system. The findings suggest that under perfect competition, global hydrogen demand from emerging end-use sectors could reach 234 Mt by 2050, with 31% met through international trade at average prices around USD 3.3/kg. Major trade corridors identified include North Africa to Europe, and South America to Japan and South Korea, revealing substantial economic benefits for importing regions when social welfare is maximized. When strategic imperfect competition is introduced, total demand in major import regions declines by up to 40% relative to perfect competition, and prices rise to a minimum of USD 4.5/kg, thereby significantly eroding consumer welfare. In contrast, cooperative behaviour can recover much of the efficiency lost under strategic competition, with all agents benefiting from cooperation. Prices decline across major import regions, while total hydrogen uptake increases by 63% relative to the non-cooperative baseline. Sensitivity analyses show that financing costs exert the strongest influence on global hydrogen trade compared with regional demand variation and import diversification policies. Overall, the thesis provides new quantitative insights into global renewable hydrogen trade and develops novel modelling frameworks to simulate the development of future hydrogen markets that support climate change mitigation objectives.7 0Item Restricted Functionalisation of Designer DNA for Nanomaterial Applications via “click” chemistry(Saudi Digital Library, 2026) ALHARTHI, Lama Saad A; Pike, AndrewAn enzymatic approach to extend DNA to give designer products of a predefined length, sequence, and functionality has been investigated. This method facilitates the extension of repetitive DNA units through repeated cycles of heating and cooling. The key elements of the reaction mixture encompass the predefined oligoseed, a thermostable DNA polymerase, and the deoxynucleotide triphosphates (dNTPs). By conducting 20 heat-cool cycles of this enzymatic method, long DNA strands of a pre-determined sequence that exceed 20,000 base pairs were obtained. The incorporation of an unnatural nucleotide, 5-C8-alkyne-dCTP, into the extending DNA during the self-priming PCR synthesis was reported. The C5 -alkyne modification is located in the major groove and was found to have a negligible impact on the DNA polymerase activity. Therefore, by tuning the starting oligoseed, long designer DNA with functionalities at pre determined positions can be synthesised. DNA carrying the 5- C8- alkyne-dCTP provides alkynyl anchoring points for further modification and space within the major groove. To explore the potential for additional functionalisation, click chemistry using azide-fluor-545 was examined. This self-priming PCR DNA synthesis approach in conjunction with non-standard dNTPS demonstrated the potential for the advancement of DNA modification via organic synthesis at targeted base positions along a designer DNA template. In a second series of experiments, click chemistry and the self-priming PCR synthesis method was again exploited to produce a series of DNA-based hydrogel-like materials. Click chemistry was performed to crosslink alkyne-bearing DNA, that had been loaded with a range of levels of alkynly modifications, with a series of diazide polyethylene glycols (PEG), N3[PEG]nN3 where n ranged from 1-9. Varying the length of the diazide-modified PEG crosslinker allowed for control over the properties of the DNA-based hydrogel materials. Self-priming PCR was also used to synthesise extended DNA that contained multiple repeats of the sequence that encodes for an elastin-like polypeptide (ELP). The predefined starting oligoseed contained two repeats of a DNA sequence that codes for the pentapeptide repetitive sequence VPGVG typical of ELPs. Extended ELPs-based DNA samples were carefully purified and then a range of specific lengths were isolated using a double well- gele electrophoresis set-up. Samples ranging in length from 100-1500 bp, were sent to collaborators for the biological expression of elastin-like protein. Three oligoseed sequences that contained 6, 19 and 22 base-repeats were designed based on naturally occurring sequences found inside cells and are known for G-quadraplex formation. Each sequence was extended using the same self-priming PCR approach and a detailed AFM investigation of their structure upon addition of two Pt (II) complexes that are known to stabilise G-quadraplexes was performed. As the oligoseed sequences are guanine rich, the potential to form G-tetrad structures in the absence/presence of to these extended oligoseeds was investigated. Overall, the modification of DNA that was produced from carefully designed oligoseed sequences using the self-priming PCR synthetic approach, demonstrates the potential of this synthetic strategy in the production of site-specific modified DNA, DNA hydrogel materials, novel biomaterials and as a tool to study the structural effects of metal complex binding to biologically important DNA sequences.6 0