SACM - Australia
Permanent URI for this collectionhttps://drepo.sdl.edu.sa/handle/20.500.14154/9648
Browse
596 results
Search Results
Now showing 1 - 10 of 596
Item Unknown The role of IL-1R8 in TLRs and IL-1Rs signaling(Saudi Digital Library, 2026) Alenzi, Nada Hnef S; Bostjan, KobeInnate immune signaling relies on the precise assembly of receptor-adaptor complexes to initiate inflammatory responses while preventing excessive activation. Interleukin-1 receptor 8 (IL-1R8, SIGIRR) is a key negative regulator of Toll-like receptor (TLR) and interleukin-1 receptor (IL-1R) pathways. Although its intracellular TIR domain was reported to be sufficient to inhibit LPS-induced TLR4 signaling, the structural basis of this inhibition has remained unclear. This thesis aimed to elucidate the structural and functional mechanisms by which IL-1R8TIR regulates TLR signaling. Using negative-stain electron microscopy and biochemical assays, IL-1R8TIR was shown to co-assemble with MALTIR into filaments morphologically distinct from MALTIR-only assemblies. The cryo-EM structure of these filaments was determined at 4.3 Å, revealing that IL-1R8TIR subunits engage MALTIR laterally rather than through the canonical head-to-tail interfaces seen in signaling-competent TIR assemblies. Additionally, IL-1R8 subunits interact with each other via previously uncharacterized interfaces. These findings suggest that IL-1R8TIR may modulate MALTIR filament formation in either a signaling-incompetent (inhibitory) or, under as-yet-unidentified conditions, a signaling-competent manner. Complementary assays further confirmed that IL-1R8TIR disrupts TRAMTIR filament formation, extending its inhibitory role to the TRIF-dependent branch of TLR4 signaling. Collectively, this thesis provides the first structural evidence of how IL-1R8TIR engages MALTIR to form higher-order assemblies, highlighting its potential dual role in regulating TLR-mediated innate immune responses.15 0Item Unknown Designing Digital Nudging for Online Grocery Stores(Saudi Digital Library, 2026) Alsaeed, Maryam; Adam, MarcOnline supermarkets have made grocery shopping easier for customers to purchase groceries remotely. The design of the user interface (UI) of online grocery stores plays a key role in shaping users’ daily food choices. However, the complexity of information and options available in these online environments can be overwhelming. Researchers in Information Systems (IS) and Human–Computer Interaction (HCI) have begun exploring digital nudging to drive user behaviour without restricting choices. This empowers system designers to use digital nudging for healthier and more sustainable food choices in online grocery stores. This thesis explores how system designers can use digital nudges to promote healthier and more sustainable food choices in online grocery stores. To begin, we1 conduct a scoping review of 74 studies from various domains (i.e., computing, health, marketing, and psychology) that focus on digital nudging in online supermarkets. Building on the Stimulus–Organism–Response (S-O-R) model, we develop a conceptual framework that outlines the design choices, theories, and outcome variables used in this context. Following this, we conduct 30 interviews as part of a qualitative study on the expertise of three stakeholder groups: online grocery store users, healthy eating experts, and user experience design experts. Drawing on these insights, we formulate six recommendations to help online grocery store designers implement digital nudges to promote healthier food choices. We also conduct an online experiment with 332 participants, building on Reactance Theory to develop a theoretical model that explores the influence of transparency on users’ acceptability of digital nudges for healthy and sustainable food choice in an online grocery setting. Overall, this thesis demonstrates that digital nudges can influence user perceptions and nudge acceptance, particularly when designed with transparency and contextual focus, providing a starting point for future research on designing digital nudging in online grocery shopping.13 0Item Unknown EXPLORATION OF NURSING KNOWLEDGE AND PRACTICES IN MANAGING PERIOPERATIVE ANXIETY IN ADULT PATIENTS(Saudi Digital Library, 2025) Alrehaili, Sumayyah; Duff, Jed; Asiri, SalihahPerioperative anxiety is a common emotional response among adult surgical patients and has been associated with longer recovery times, increased postoperative pain, and reduced patient satisfaction. Nurses, as the primary caregivers throughout the surgical journey, play a central role in helping patients manage this anxiety through emotional support, education, and therapeutic presence. Although previous studies have demonstrated the effectiveness of interventions such as psychoeducation and relaxation therapy, limited research has explored how nurses themselves perceive, assess, and manage perioperative anxiety in their daily practice, particularly within the Saudi healthcare context. This qualitative interpretive study aimed to explore perioperative nurses’ knowledge, experiences, and practices in managing anxiety among adult surgical patients in Jeddah, Saudi Arabia. Guided by Watson’s Theory of Human Caring, the study emphasised holistic and empathetic care as a foundation for understanding how nurses support anxious patients. Semi-structured interviews were conducted with nine registered nurses to examine how caring principles are reflected in their approaches to recognising and alleviating perioperative anxiety. The findings revealed that nurses view anxiety as a natural and universal human experience rather than a pathological condition. They identified anxiety through physiological and behavioural signs and managed it using reassurance, patient education, and spiritual and cultural support. These caring actions reflected Watson’s caritas processes, such as sustaining faith and hope, building trust, and creating a supportive healing environment. However, systemic barriers, including staff shortages, time constraints, lack of training, and the absence of formal institutional guidelines, restricted nurses’ ability to provide consistent holistic care. The study concludes that while nurses demonstrate a moral and cultural commitment to alleviating anxiety, organisational and educational gaps limit the full application of caring principles in perioperative settings. Integrating Watson’s theory into education, policy, and practice can bridge this gap and promote human-centred care. Future research should incorporate patients’ perspectives and evaluate the effectiveness of caring-based interventions across cultural contexts to strengthen the quality of perioperative nursing care and reaffirm nursing’s essential role in creating safe, compassionate, and healing surgical experiences5 0Item Unknown Context-Aware Fake News Detection Using Deep Learning(Saudi Digital Library, 2026) Alghamdi, Jawaher; Suhuai, Luo; Yuqing, LinThe pervasive spread of fake news (i.e., intentionally misleading information presented as legitimate news) on social media poses a pressing global challenge, distorting public discourse and undermining societal trust. Fake news is often crafted to imitate credible sources and exploit human judgment while leveraging the ways social media prioritizes and disseminates content. This thesis investigates fake news detection (FND) through deep learning (DL) approaches that extend beyond content-only analysis to incorporate contextual and behavioral signals. The primary objective is to develop scalable, accurate, and interpretable (i.e., capable of providing transparent and human-understandable reasoning for predictions) FND systems that can operate effectively across diverse domains and languages. Early detection methods relied heavily on surface-level or manually engineered content features, which proved insufficient for identifying sophisticated forms of fake news. To address these limitations, this thesis introduces hybrid architectures that combine transformer-based encoders with convolutional, recurrent, and attention mechanisms, integrating semantic, linguistic, stylistic, and context-aware features. These models capture both fine-grained textual cues and broader semantic relationships spanning entire articles, enhancing the ability to differentiate factual content from misleading narratives. Beyond textual signals, the work incorporates user metadata, posting histories, temporal dynamics, and relationships across headlines, article bodies, and comments, strengthening detection in situations where textual evidence alone is ambiguous. Scalability is approached through parameter-efficient fine-tuning, where lightweight adapters are integrated into transformer models. A novel fusion mechanism balances general pre-trained knowledge with task-specific information, while selective layer-wise adaptation focuses on semantically critical layers to maximize efficiency. To improve multilingual coverage, the thesis proposes a hybrid summarization technique that distills salient information and reduces redundancy, enabling robust performance without dependence on translation pipelines. This framework operates effectively in both high-resource and low-resource languages, supporting inclusive and scalable deployment. The thesis also tackles cross-domain generalization, introducing domain-adaptive models that extend FND to diverse topics and formats. One approach reframes FND as a prompt-based zero-shot learning (ZSL) task, employing cloze-style prompts and domain-aware augmentation to improve adaptability without fine-tuning. A second approach employs domain-specific expert subnetworks enriched with topic and entity information, combined with adversarial learning to mitigate domain bias. Experiments on multiple benchmark datasets confirm the effectiveness of these methods, achieving state-of-the-art (SOTA) performance. Results demonstrate that the integration of content, context, and propagation-aware signals substantially enhances FND. In summary, this thesis delivers a suite of DL solutions that advance efficiency, robustness, and adaptability in FND. The work addresses scalability, multilinguality, and cross-domain resilience, offering practical and deployable tools for countering the global threat of fake news across platforms, domains, and languages.5 0Item Unknown The Impact of Supervisor Incivility on Subordinates’ Thriving at Work: The Role of Psychological Capital and Competitive Psychological Climate(Saudi Digital Library, 2026) ALJURAIBI, MOHAMMED; Almeida, Shamika; Lee, ThomasBackground: Supervisor incivility is increasingly prevalent in today's fiercely competitive business landscape. While numerous societies adhere to a general norm of civility, not all organisations or organisational members may share a uniform perspective regarding demonstrating respect for one another in the workplace. There may be increased supervisor incivility within organisations, as these supervisors can implement the strategies necessary for business success. This raises important questions about the implications of supervisor incivility for employees' mental health and job performance. This study specifically focuses on those employees who have experienced and witnessed incivility from their supervisors. Research suggests that supervisors' behaviour can influence employees' wellbeing. This study focuses on thriving at work, representing a more active state than wellbeing, emphasising continuous growth and learning. Wellbeing emphasises comfort and stability while thriving concerns adaptation and progress. This concept is especially relevant in competitive environments, where maintaining motivation and productivity involves feeling connected to growth and development and not just avoiding burnout. While existing literature has acknowledged the impact of supervisors on employees' wellbeing, there remains a gap in understanding how supervisor incivility— especially witnessed—affects employees' ability to thrive at work. Aim: The study examines the relationship between supervisor incivility and employee thriving at work. The study addresses three research objectives. First, it seeks to determine the differences among the types of supervisor incivility. Second, it examines the effect of supervisor incivility (experienced and witnessed) on employees thriving at work. Third, it seeks to investigate the indirect influence of the two types of supervisor incivility on subordinates' thriving at work through Psychological Capital (PsyCap) (mediator), with Competitive Psychological Climate (CPC) (moderator) as the boundary condition. The study utilises the Transactional Theory of Stress (TTS) to understand how individuals appraise and respond to workplace challenges and Social Learning Theory (SLT) to provide insight into how employees adopt behaviours based on observed interactions, underpinning the effects of managerial behaviours on employee thriving. Method: A mixed methods approach is used to collect and analyse the data, including surveys and interviews. Using an online survey approach in the main study, Phase One, data were gathered from 412 Junior Medical Officers (JMOs) in Saudi Arabia and analysed using the Statistical Package for Social Sciences (SPSS), regression, and PROCESS macro. Using the interview approach in Phase Two, data were gathered from 25 JMOs and analysed using thematic analysis to comprehend the findings of Phase One. Results: Phase one of the study showed that the levels of PsyCap and the thriving of subordinates vary in line with the type of supervisor incivility in increasingly competitive and pressured workplace environments. Specifically, the findings show that supervisor incivility affects employees' PsyCap. Further, the indirect effect of supervisor incivility on thriving at work through PsyCap is weaker when the CPC is low and stronger when it is high. In a highly competitive work environment, experiencing supervisor incivility results in lower PsyCap. However, it weakened the relationship between witnessed supervisor incivility and PsyCap. Hence, a subordinate appraised witnessing supervisor incivility as a challenge, increasing PsyCap and, in turn, thriving at work. Phase Two of the study explored why subordinates considered supervisor incivility as a challenge. The main reasons that participants highlighted were fear, personal agendas, desire to be in the in-group with their supervisor and cultural values such as respect. The findings also highlighted how JMOs learnt to adapt to incivility, used negative peer experiences as lessons on what to avoid at work with their supervisors and focused on long-term outcomes. All these mechanisms enabled them to thrive at work. Overall, the results showed that supervisor incivility has a bright side in competitive climates and helps employees thrive at work. Contributions and Implications: This study addresses gaps in the literature on supervisor incivility and how employees in high-stress environments, such as healthcare, appraise and manage uncivil behaviour. The present study contributes to knowledge by identifying coping responses, competitive climate, social process, and psychological capital as possible reinforcements of the supervisor witnessed incivility. As such, the study model can be used to understand the negative and positive findings concerning supervisor incivility. The study also provides a Middle Eastern perspective on the types of incivility and their effects on workplace thriving. Empirically, it examines the dual perspectives of victims and observers, offering new insights into how both experienced and witnessed supervisor incivility impact thriving at work. Theoretical contributions include applying TTS to clarify appraisal processes and conditions under which incivility affects subordinates and using SLT to understand why observed supervisor incivility helps employees thrive at work. Practically, the study guides organisations in creating supportive policies and strategies for enhancing employee thriving. It also gives supervisors insights into how their behaviour influences employee responses, ultimately improving organisational effectiveness.11 0Item Unknown The Impacts of Western Theories: Application to Professional Social Work Practice in Saudi Arabia(Saudi Digital Library, 2025) Barasayn, Nouf; Clark, JulieThis study examines the impact of western social work education on decision-making among Saudi Arabian social workers within an Islamic context. Specifically, it investigates the integration of theoretical frameworks learned at university into practical social work, exploring factors such as professional experience, religious beliefs, and cultural influences that may shape decision-making. Research questions address whether social workers recall and utilize theories from their studies, the influence of practicing in an Islamic society, and potential conflicts between Western theories and Islamic values. Findings reveal that while social work education has significantly shaped professional practices—particularly through problem-solving skills and systematic approaches—many social workers are also guided by religious values in their practice. The research highlights that, for the majority, Western social work principles, including client dignity, respect, and autonomy, align with Islamic values, suggesting successful integration of these frameworks into their professional identity. Approximately twenty percent of participants did experience some tension between academic education and real-world practice but those social workers with longer experience in the field felt more confident in their interventions and decision-making. The study underscores the universal applicability of social work values and professional processes and how they transcend cultural circumstances and world views. This research contributes to a deeper understanding of how non-western cultural and religious values intersect with Western social work-oriented education in a manner which leads to a selection of interventions by social workers which adhere to principles of competent practice. At the same time these values are deeply rooted in the culture of the society in which they are practiced and are adapted to fit within context specific agency policies. The findings provide a basis for curriculum enhancements that support culturally competent practice in Saudi Arabia and similar settings.Item Unknown The Impact of Supervisor Incivility on Subordinates’ Thriving at Work: The Role of Psychological Capital and Competitive Psychological Climate(Saudi Digital Library, 2026) ALJURAIBI, MOHAMMED; Almeida, ShamikaBackground: Supervisor incivility is increasingly prevalent in today's fiercely competitive business landscape. While numerous societies adhere to a general norm of civility, not all organisations or organisational members may share a uniform perspective regarding demonstrating respect for one another in the workplace. There may be increased supervisor incivility within organisations, as these supervisors can implement the strategies necessary for business success. This raises important questions about the implications of supervisor incivility for employees' mental health and job performance. This study specifically focuses on those employees who have experienced and witnessed incivility from their supervisors. Research suggests that supervisors' behaviour can influence employees' wellbeing. This study focuses on thriving at work, representing a more active state than wellbeing, emphasising continuous growth and learning. Wellbeing emphasises comfort and stability while thriving concerns adaptation and progress. This concept is especially relevant in competitive environments, where maintaining motivation and productivity involves feeling connected to growth and development and not just avoiding burnout. While existing literature has acknowledged the impact of supervisors on employees' wellbeing, there remains a gap in understanding how supervisor incivility— especially witnessed—affects employees' ability to thrive at work. Aim: The study examines the relationship between supervisor incivility and employee thriving at work. The study addresses three research objectives. First, it seeks to determine the differences among the types of supervisor incivility. Second, it examines the effect of supervisor incivility (experienced and witnessed) on employees thriving at work. Third, it seeks to investigate the indirect influence of the two types of supervisor incivility on subordinates' thriving at work through Psychological Capital (PsyCap) (mediator), with Competitive Psychological Climate (CPC) (moderator) as the boundary condition. The study utilises the Transactional Theory of Stress (TTS) to understand how individuals appraise and respond to workplace challenges and Social Learning Theory (SLT) to provide insight into how employees adopt behaviours based on observed interactions, underpinning the effects of managerial behaviours on employee thriving. Method: A mixed methods approach is used to collect and analyse the data, including surveys and interviews. Using an online survey approach in the main study, Phase One, data were gathered from 412 Junior Medical Officers (JMOs) in Saudi Arabia and analysed using the Statistical Package for Social Sciences (SPSS), regression, and PROCESS macro. Using the interview approach in Phase Two, data were gathered from 25 JMOs and analysed using thematic analysis to comprehend the findings of Phase One. Results: Phase one of the study showed that the levels of PsyCap and the thriving of subordinates vary in line with the type of supervisor incivility in increasingly competitive and pressured workplace environments. Specifically, the findings show that supervisor incivility affects employees' PsyCap. Further, the indirect effect of supervisor incivility on thriving at work through PsyCap is weaker when the CPC is low and stronger when it is high. In a highly competitive work environment, experiencing supervisor incivility results in lower PsyCap. However, it weakened the relationship between witnessed supervisor incivility and PsyCap. Hence, a subordinate appraised witnessing supervisor incivility as a challenge, increasing PsyCap and, in turn, thriving at work. Phase Two of the study explored why subordinates considered supervisor incivility as a challenge. The main reasons that participants highlighted were fear, personal agendas, desire to be in the in-group with their supervisor and cultural values such as respect. The findings also highlighted how JMOs learnt to adapt to incivility, used negative peer experiences as lessons on what to avoid at work with their supervisors and focused on long-term outcomes. All these mechanisms enabled them to thrive at work. Overall, the results showed that supervisor incivility has a bright side in competitive climates and helps employees thrive at work. Contributions and Implications: This study addresses gaps in the literature on supervisor incivility and how employees in high-stress environments, such as healthcare, appraise and manage uncivil behaviour. The present study contributes to knowledge by identifying coping responses, competitive climate, social process, and psychological capital as possible reinforcements of the supervisor witnessed incivility. As such, the study model can be used to understand the negative and positive findings concerning supervisor incivility. The study also provides a Middle Eastern perspective on the types of incivility and their effects on workplace thriving. Empirically, it examines the dual perspectives of victims and observers, offering new insights into how both experienced and witnessed supervisor incivility impact thriving at work. Theoretical contributions include applying TTS to clarify appraisal processes and conditions under which incivility affects subordinates and using SLT to understand why observed supervisor incivility helps employees thrive at work. Practically, the study guides organisations in creating supportive policies and strategies for enhancing employee thriving. It also gives supervisors insights into how their behaviour influences employee responses, ultimately improving organisational effectiveness.Item Unknown The Role of Self-reference in Initial Lexical Acquisition(Saudi Digital Library, 2026) Qahl, Taghreed; Lambert, CraigThis hybrid-model thesis aims to address three questions: (1) How do the four self-referential processing (self, intimate, familiar, and semantic) impact item and source memory for novel L2 lexical items? (2) Do emotional valence and self-referential processing interact with respect to item and source memory? (3) Do self-esteem and self-referential processing interact with respect to item and source memory? Three studies were conducted in response to each question: Study 1: Personal Investment in Language Processing: The Role of Self-Reference in Initial Lexical Acquisition This study investigates the role of self-reference in the initial stages of second language (L2) lexical acquisition. The study is motivated by recent trends in second language acquisition (SLA) research that highlight the positive effects for treatments that draw on learners’ background experiences (e.g., Boudreau et al., 2018; Lambert et al., 2017; Lambert et al., 2023b; Lambert & Zhang, 2019; MacIntyre & Wang, 2021; Stranger-Johannessen & Norton, 2017, 2019). However, the role of the learner in SLA remains undertheorized (Swain, 2013; Lambert, 2023), and further work is needed to identify the specific mechanisms responsible for documented effects and their role in language processing. One such mechanism might be self-reference, which refers to information processed with reference to the self that is typically better remembered than information processed with reference to others (Hamami et al., 2011; Leshikar et al., 2015; Symons & Johnson, 1997). Accordingly, the present study investigates the impact of self-reference on the establishment of form-to-meaning connections during the initial acquisition of L2 lexis in item memory (the meaning of each item) and source memory (the conditions under which the items were processed). 144 Saudi female undergraduate English as a Foreign Language (EFL) learners processed 20 novel L2 trait adjectives counterbalanced across four processing conditions in which they considered each trait with reference to themselves, an intimate other, a familiar other, or a known lexical item. Findings revealed that information processed under personal investment conditions (self-reference and intimate-other reference) was recalled significantly better than information processed under non-personal investment conditions (familiar-other and semantic reference) in both item and source memory. Overall, low-proficiency EFL learners recalled more information when it was personally relevant. Study 2: Emotional Valence, Personal Investment and Initial L2 Lexical Acquisition This study examines the effect of emotional valence in memory for L2 lexical items in interaction with self-referential processing. The study employed a repeated measures design in which the participants processed 20 novel L2 trait adjectives (10 positively and 10 negatively valenced). Lexical items were counterbalanced across conditions and participants, with each lexical item occurring an equal number of times in each condition to control for the effects of specific lexical items. The study reveals that participants recalled negative emotional valence words processed in the personal investment conditions significantly better than in the non-personal investment conditions. Study 3: Domain-Specific Self-Esteem, Personal Investment, and Initial L2 Lexical Acquisition This study investigates self-esteem in memory for novel lexis in interaction with self-reference. Learners evaluated their self-esteem at the time each item was processed. They later recalled the meaning of each item (item memory) and the conditions under which they processed it (source memory). Results revealed that self-esteem interacted significantly with processing condition, in which learners with high self-esteem recalled items processed in the personal investment conditions significantly better than in the non-personal investment conditions in terms of both item and source memory. Personal investment and self-esteem thus had synergistic effects. The thesis contributes to illuminating processes underlying personal investment theory as a basis for research on the role of the learner in second language acquisition (SLA). It also provides insight into how affective factors influence the establishment of initial form-to-meaning relationships in novel L2 lexical acquisition.Item Unknown Exploring the Properties and Stabilisation of Nanoscale Metal Cluster/Overlayer Architectures(Saudi Digital Library, 2026) Asiri, Mohammed; Ebendorff-Heidepriem, HeikeThe shift from fossil fuels to renewable energy sources is a major focus in the global effort to reduce CO2 emissions, with photocatalytic hydrogen production being a promising approach for harvesting energy from sustainable energy sources. Photocatalysts absorb energy from sunlight to drive the water splitting reaction, producing H2. The deposition of a co-catalyst, such as noble metal clusters, can modify and improve the efficiency of the photocatalyst. Metal clusters, consisting of only a few atoms, have gained attention as co-catalysts due to their unique electronic and catalytic properties. However, maintaining their size and stability is challenging, as they tend to agglomerate into larger particles, losing their unique properties. Another challenge is the occurrence of the back reaction during photocatalysis, when H2 and O2 react to form water on the co-catalyst surface. The back reaction reduces the efficiency of photocatalytic water splitting. Atomic Layer Deposition (ALD) of thin metal oxide overlayers on cluster-modified photocatalysts offers a strategy to stabilise the clusters and suppress the back reaction. The self-limiting nature of ALD allows for deposition of an ultrathin overlayer with a controllable thickness. This thesis investigates how ALD-AlOx overlayers can be used to preserve the integrity of noble metal clusters, particularly Au clusters. It is examined how an ALD-AlOx overlayer grows on the surface of a photocatalyst formed by depositing Au clusters on TiO2 surfaces, as well as the distribution and stability of the clusters on the TiO2 surface before and after the ALD overlayer. The growth of ALD-AlOx overlayers on Au101/TiO2 was investigated as a model photocatalyst system to understand how the overlayer grows on the Au clusters and the TiO2 substrate. The investigation determines the overlayer thickness after applying several ALD cycles on a planar TiO2 substrate. The study demonstrated that the ALD-AlOx resulted in evenly deposited overlayers for the system of Au101/TiO2 with a slight tendency to be thicker on the Au cluster than on the TiO2. The layer thicknesses were found to be 2.0 Å, 3.5 Å, and 5.5 Å for 1, 5, and 10 ALD cycles, respectively. A comprehensive study of the stability of Au9(PPh3)8(NO3)3 deposited onto TiO2 by depositing an ultrathin overlayer of ALD-AlOx at various deposition temperatures, 25 °C, 100 °C, 150 °C, and 200 °C was conducted. It was found that ALD-AlOx stabilised Au9 clusters on the TiO2 surface across various temperatures. Notably, the phosphine ligands desorb during the ALD overcoating process at elevated temperatures, while the Au9 cores remained protected beneath the AlOx overlayer. The ALD-AlOx overlayer on Au metal clusters on TiO2 was studied by a combination of microscopic and spectroscopic techniques. It was revealed that the Au101 clusters were distributed randomly across the entire TiO2 surface. The roughness of the Au101/TiO2 system increases as the Au concentration increases, while ALD overcoating smooths the clusters, as the roughness was found to decrease, indicating a uniform coating on clusters by forming thicker overlayers on interstitial regions between clusters. This work provides an understanding of the role of ALD-AlOx overlayer on the stabilisation of Au metal clusters on TiO2 as a photocatalyst model system, with direct relevance of designing and improving photocatalytic water splitting for green hydrogen production.Item Unknown Identification of groundwater flow patterns and barriers in aquifers(Saudi Digital Library, 2025) Asiri, Mohammed; Shelyag, Sergiy; Miller, TonyThe use of inverse methods has been increasing in hydrology. Numerical methods can help identify groundwater barriers and flow patterns in an aquifer, which can reduce errors when comparing the exact and estimated solutions. This thesis uses the method of characteristics (MOC) to identify transmissivity T in an area of abnormal region. From Darcy’s law for steady-state groundwater flow, we start with a one-dimensional case, which helps us consider what may and may not be in the two-dimensional case. Then we use the 2D case to calculate the stream function and find that the gradient of the stream function is orthogonal to the gradient of the head, and we use this when calculating the stream function everywhere. We use MODFLOW to generate head data for the known distribution T and to estimate T under different inflow examples. MOC gives a stable solution and can help identify the area of low T without requiring smoothness of the T distribution.