SACM - Malaysia
Permanent URI for this collectionhttps://drepo.sdl.edu.sa/handle/20.500.14154/9660
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Item Restricted ENHANCEMENT OF ZnO-BASED UV PHOTODETECTORS BY INCORPORATING Bi2O3, Ag, AND Ge NANOSTRUCTURES SYNTHESIZED USING LASER ABLATION IN LIQUID(Saudi Digital Library, 2025) Alharbi, Abdullah Marzouq; Assoc, Azhar Abdul RahmanABSTRACT This research enhances the efficiency of UV photodetectors through the synthesis and integration of nanoparticles using laser ablation techniques. The study investigates the effects of bismuth oxide nanosheets (Bi2O3-Nsh), silver nanoparticles (AgNPs), and germanium nanowalls (GeNWs) on ZnO/Si-based UV photodetectors. By change nanoparticle size and shape, the research aims to improve responsivity, sensitivity, and overall performance. Comprehensive characterization of the synthesized nanoparticles and their integration into photodetector architectures was conducted to evaluate their effectiveness and potential for practical applications. Bi2O3 nanosheets (Bi2O3-Nsh) were synthesized using the laser ablation in liquid (LAL) method. The Bi2O3-Nsh were integrated into ZnO/Si photodetectors, and their crystalline structures, morphologies, and optical properties were characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray (EDX), and UV-visible spectroscopy analysis. The UV photodetection performance was assessed under 385 nm UV light at varying bias voltages. The ZnO/Bi2O3-Nsh/Si-based UV photodetectors demonstrated a strong response, with the I-V curve showing a significant change from 79 μA to 20 mA at 6 V. Additionally, the device exhibited the highest responsivity of 49.8 A/W, quantum efficiency of 161.61, sensitivity of 25000%, gain of 251, detectivity of 9.86 × 1010 Jones, and a noise equivalent power (NEP) of 1.01 × 10-12 W under 385 nm UV light at a bias voltage of 6 V. These results highlight the potential of Bi2O3-Nsh in enhancing xix ZnO/Si photodetectors. The research also synthesized AgNPs using a cost-effective laser ablation technique combined with RF sputtering. The AgNPs were encapsulated by zinc oxide on a silicon substrate to enhance photodetector efficiency while reducing costs. Three sample configurations (AgNPs/Si, AgNPs/ZnO/Si, and ZnO/AgNPs/Si) were characterized using FESEM, XRD, EDX, and UV-visible spectroscopy. The ZnO/AgNPs/Si photodetector exhibited the highest performance, with a peak responsivity of 132 A/W, quantum efficiency of 429.88, sensitivity of 31400%, gain of 315, detectivity of 18 × 1010 Jones, and an NEP of 0.556 × 10-13 W. These findings underscore the potential of AgNPs in enhancing UV photodetector performance and the feasibility of cost-effective synthesis methods. Furthermore, GeNWs were synthesized via pulsed laser ablation to improve UV photodetection. The GeNWs were integrated into ZnO/Si photodetectors in two configurations: ZnO/GeNWs/Si and GeNWs/ZnO/Si. The ZnO/GeNWs/Si configuration showed impressive performance, with a photocurrent of around 12.8 mA at 6 V, indicating significant enhancement in UV light absorption and carrier charge transport. The device exhibited a responsivity of 31.8 A/W, quantum efficiency of 103.43, sensitivity of 9600%, and detectivity of 4.90 × 1010 Jones. These results demonstrate the potential of GeNWs to enhance UV photodetector performance and the effectiveness of pulsed laser ablation. This research successfully addresses the objectives by using laser ablation techniques to synthesize and integrate Bi2O3-Nsh, AgNPs, and GeNWs into UV photodetectors.5 0Item Restricted Exploring the Impact of Talent Management Strategies on AI Adoption in Saudi Arabia’s Emerging Tech Startups: The Mediating Role of Knowledge Sharing(Saudi Digital Library, 2025) Abuhaimed, Mohammad Saad; Abdoulrahman Aljounaidi Mhd RamezSaudi Arabia's Vision 2030 emphasizes AI-driven digital transformation, yet tech startups struggle to scale AI beyond pilots. Purpose: This study examines how talent management (TM) strategies—attracting-selecting (AST), developing (DT), empowering (ET), retaining (RT), and career succession (CS)—shape AI adoption, and whether knowledge sharing (KS) mediates this relationship. Method: Using probability-based systematic random sampling of employees (n=337, N=2,308) across Saudi AI-adopting startups, the model was analyzed with PLS-SEM (SmartPLS 4). Findings: AST, DT, and ET positively affect AI adoption; RT shows no effect; CS exhibits a negative effect. KS partially mediates AST, DT, ET, and CS effects, indicating TM practices influence adoption primarily through knowledge institutionalization. Implications—Industrial: Startup leaders should integrate KS infrastructures with TM initiatives. Recommended practices: (1) cross-functional AI taskforces with rotating membership; (2) peer-learning sessions where early adopters mentor colleagues; (3) searchable repositories (wikis, Confluence) documenting implementation lessons and troubleshooting guides; (4) succession systems prioritizing collaborative knowledge transfer (mentoring, communities of practice) to prevent silos. Empirical evidence shows succession planning without KS scaffolding correlates negatively with adoption (β = -0.182, p < .01), highlighting knowledge-hoarding risks. Academic: The study extends technology-acceptance theory by integrating human-capital antecedents and positioning KS as the pivotal mediating mechanism in resource-constrained startups. Testing 16 structural paths across five TM dimensions addresses three gaps: (1) mechanistic under-specification, (2) construct aggregation bias, and (3) non-Western context neglect. The mediation framework—validated through bootstrapped indirect effects—provides a replicable blueprint for future research examining causality, moderators (industry velocity, founder literacy), and boundary conditions.38 0Item Restricted PERFORMANCE OF FREE-SPACE OPTICS TRANSMISSION SYSTEM USING ADVANCED MULTIPLEXING TECHNIQUES UNDER SAUDI ARABIAN WEATHER CONDITION(Saudi Digital Library, 2025) HAKAMI, ALI HADI; Din, Jafri BiFreespace optics (FSO) communication is a promising technology for high-speed and cost-effective data transmission in both terrestrial and non-terrestrial networks. This research evaluates the performance of advanced multiplexing techniques including orbital angular momentum (OAM), polarization division multiplexing (PDM), orthogonal frequency division multiplexing (OFDM), and in-phase/quadrature modulation (IQM) under representative Saudi Arabian atmospheric conditions. Visibility measurements from the Meteorological Department for Jazan and Riyadh were employed in this analysis. Atmospheric attenuation was modeled using the Kim, Kruse, and Al-Naboulsi approaches. OptiSystem and MATLAB were employed for system implementation and channel modeling, evaluating capacity gain and attainable distance range, with other performance metrics including bit error rate (BER), eye diagrams, and Q-factor evaluated for all objectives. The first objective examined OAM-based FSO systems, showing moderate capacity gains of up to 40 Gbps across 4 km under clear conditions. The second objective assessed OAM–PDM integration, effectively doubling capacity to 80 Gbps without extending the transmission range. The third objective investigated a hybrid IQM–OAM–PDM–OFDM design, achieving the highest performance: up to 640 Gbps over ~15 km under Kim and Kruse models, and ~7.25 km under the Al-Naboulsi model, with additional evaluation of Error Vector Magnitude (EVM) and Forward Error Correction (FEC) to further reduce BER. These findings confirm the sequential achievement of the research objectives and demonstrate that combining advanced multiplexing and modulation techniques, alongside probabilistic performance matrices, significantly enhances both capacity and transmission range. The results provide practical insights for the design of next-generation FSOs that are resilient to atmospheric impairments in Saudi Arabia.8 0Item Restricted A Study on Enhancing Construction Efficiency, Implementing Project Management Principles among Contractors in the Kingdom of Saudi Arabia(Saudi Digital Library, 2024) AlHameed, AlFadaly Abd; Mohamad, NasaniThis dissertation investigates the challenges facing the construction industry in developing countries, despite its significant economic contribution and employment opportunities. Drawing on data from Ofori (2006), Jekale (2004), and Idoko (2008), it examines the prevalent issues such as time and cost overruns, poor-quality infrastructure, and inefficiencies in resource allocation. The study highlights the detrimental effects of time and cost overruns on project schedules, budgets, and overall economic progress. It also explores the factors contributing to these overruns, including inadequate planning, project management deficiencies, and regulatory obstacles. Furthermore, the dissertation delves into the consequences of poor-quality infrastructure on societal well-being and economic development. It discusses the root causes of substandard construction practices, lack of skilled labor, and inadequate quality control measures. Moreover, the research sheds light on the inefficiencies in resource allocation and utilization within the construction sector of developing countries. It identifies barriers such as limited access to capital, outdated technology, and resistance to innovation. The dissertation concludes by advocating for collaborative efforts among governments, private sector stakeholders, and international organizations to address these challenges. It suggests strategies such as infrastructure investment, vocational training enhancement, regulatory reform, and technology adoption to improve the performance and competitiveness of the construction industry in developing countries.6 0Item Restricted INVESTIGATION OF MSM UV PHOTODETECTOR BASED ON PLASMONIC EFFECT OF METALS NANOPARTICLE DECORATED POROUS SILICON(Saudi Digital Library, 2025) ARISHI RAED, ABDULLAH; Ahmed, Nasser Mohamad; Samsuri, Siti Azrah MohamadPhotodetectors (PDs) are essential in ultraviolet (UV) sensing, biomedical diagnostics, environmental monitoring, and optical communication; however, conventional silicon-based devices suffer from poor UV sensitivity and surface recombination defects. Porous silicon (PS) provides a promising platform due to its high surface area and strong light-trapping capability, while integrating metallic nanoparticles (NPs) can induce surface plasmon resonance (SPR) to enhance light absorption and charge carrier generation. This study investigates and compares the plasmonic effects of Ag, Au, Cu, and Ni nanoparticles on PS-based PDs to improve UV detection efficiency. PS was fabricated using photoelectrochemical etching (PECE), while NPs were synthesized by pulsed laser ablation in liquid (PLAL) and deposited on PS using drop-casting. We performed electrical (I–V and I–T) measurements under dark and UV conditions, along with FESEM, XRD, and UV-Vis NIR analyses. The Au NPs/PS device achieved the highest sensitivity (37,465%) with rise and decay times of 0.232 s and 0.20 s, respectively, because of Au's chemical inertness, while Cu NPs/PS showed the lowest sensitivity (640%) with rise and decay times of 0.321 s and 0.22 s, respectively, due to Cu's high oxidation tendency. These results demonstrate the critical role of nanoparticle material selection in enhancing PS based PDs and underline their potential applications in UV sensing, secure optical communication, flame detection, and space exploration. This work provides a clear pathway for developing high-performance plasmon-enhanced PDs with improvez sensitivity, stability, and applicability.28 0Item Restricted THE EFFICACY OF MECHANICAL ROTARY, CHEMICAL SOLVENT AND LASER-ACTIVATED IRRIGATION TO REMOVE INTRACANAL OBTURATION MATERIAL WITH VARIOUS TYPE OF SEALER IN RETREATMENT ENDODONTIC(Saudi Digital Library, 2025) Alshammari, Ahad; JUZAILAH, BINTI ROFFIEThis study aimed to evaluate the efficacy of different retreatment protocols in eliminating root canal filling materials (RCFM) from extracted human premolars and to assess the influence of sealer type on removal performance. Thirty-six single-rooted specimens were allocated into four groups based on the retreatment method: Group 1 - ProTaper Universal Retreatment (PTUR), Group 2 - PTUR + chloroform, Group 3 - PTUR + laser-activated irrigation (LAI), and Group 4 - PTUR + chloroform + LAI. Each group was further subdivided according to sealer type: AH Plus, MTA Fillapex, and CeraSeal (n = 3 per subgroup). Apical patency was assessed post-retreatment. The remaining obturation material was analyzed using micro-computed tomography (micro-CT) to quantify its volume and stereomicroscopy to examine remnants on the canal walls. Statistical analyses included the Chi-Square test for apical patency and a two-way ANOVA with Tukey's post hoc test for quantitative measurements. No significant differences in apical patency were observed among the groups (p= 1.000). Group 4 exhibited the lowest levels of retained material (p = 0.0037), suggesting enhanced efficiency. Among the sealers, MTA Fillapex was associated with a higher amount of remaining debris compared to AH Plus and CeraSeal. In conclusion, the combined use of PTUR, chloroform, and LAI proved more effective in debriding root canals without adversely affecting apical patency. These findings support the clinical benefit of integrating both solvent and laser-assisted techniques during retreatment procedures.14 0Item Restricted GENERALIZED CLOSED SETS AND THEIR APPLICATIONS IN FUZZY BITOPOLOGICAL SPACES(Universiti Putra Malaysia, 2024) ALHARBI, AHLAM AHMED; KILICMAN, ADEMAbstract of thesis presented to the Senate of Universiti Putra Malaysia in fulfilment of the requirement for the degree of Doctor of Philosophy GENERALIZED CLOSED SETS AND THEIR APPLICATIONS IN FUZZY BITOPOLOGICAL SPACES By ALHARBI, AHLAM AHMED M December 2024 Chairman : Adem Kilicman, PhD Faculty : Science The present thesis focuses on studying generalized closed subsets of fuzzy bitopology spaces, which is an emerging field of mathematics, especially in fuzzy bitopology. This field of study combines fuzzy sets, fuzzy bitopology, and generalizations of fuzzy closed sets to provide a thorough structure for describing and analyzing complicated systems. We introduce new results on generalized closed sets and their applicationsin fuzzy bitopological spaces. Thus, more profound insights into continuity, connectedness, and compactness are made possible, and a greater knowledge of functions, relationships, separation axioms, normal space, and regular space within fuzzy bitopological contexts is reached. This, in turn, provides a comprehensive framework or studying and evaluating complex systems. We began the thesis by recalling the fundamental concepts of fuzzy structures and basic theorems for the remainder of the thesis, providing a quick reference for the reader’s convenience. After that, we defined and introduced some kinds of generalized closed subsets of fuzzy bitopology spaces. The definition of a generalized closed setrelies on two factors: openness and closure. We established the open operator in the first fuzzy topology (𝜏𝑖), while the closure operator in the second topology (𝜏𝑗) varies across different types, such as fuzzy closure, fuzzy 𝛼-closure, fuzzy semi-closure, fuzzy pre-closure, and fuzzy 𝛽-closure. This creates different types of generalized closed subsets in fuzzy bitopological spaces, which we call (𝑖, 𝑗) − 𝑓𝑔𝜑−closed to make studying them easier, where 𝑖, 𝑗 ∈ {1, 2} and 𝑖 ≠ 𝑗. Then, we explored various theorems, properties, and their relationships with important counterexamples. On the other hand, delving into each theory or topic with the fuzzy sample (𝑖, 𝑗) − 𝑓𝑔𝜑−closed group is complex, comprehensive, and correct for all the types of generalized closed sets involved.Furthermore, this thesis introduces their application to mathematical structures. We started by introducing generalized neighborhood concepts using the (∈) connection and the quasi-coincident idea (𝑞) in fuzzy bitopological spaces. We also analyze them according to their properties, which are supported by counterexamples. In addition, we presented types of generalized functions, which consist of five sections: generalized continuous, generalized strong continuous, generalized irresolute, and generalized open and closed functions. The last section is the generalized homeomorphism, which includes some theorems, compositions, corollaries with important examples, and diagrams to show relationships between concepts. Moreover, this thesis presents definitions, results, and links related to the concepts of generalized compactness and generalized connectedness. Next, various types of fuzzy generalized separation axioms are studied by explaining several important theorems and counterexamples.In conclusion, new definitions of generalized regular space, generalized normal space, generalized 𝑇3, and generalized 𝑇4 are discussed. In addition, new theorems, basicproperties, and important counterexamples for both are defined. The results of this study are novel and more comprehensive because of the compact structure of generalized closed groups of fuzzy bitopological spaces. Additionally, the application of all previous mathematical concepts offers advantages in certain aspects. Keywords: Fuzzy generalized closed sets, fuzzy generalized neighborhoods, fuzzy generalized functions, fuzzy generalized compactness and connectedness, fuzzy generalized separation axioms. Keywords: Fuzzy generalized closed sets, fuzzy generalized neighborhoods, fuzzy generalized functions, fuzzy generalized compactness and connectedness, fuzzy generalized separation axioms. SDG: GOAL 4: Quality Education, GOAL 9: Industry, Innovation and Infrastructure.5 0Item Restricted EVALUATING THE EFFECTIVENESS OF WAYFINDING SYSTEMS IN URBAN METRO STATIONS DURING HAJJ ALGHAMDI, KHALID(UTM, 2025) ALGHAMDI, KHALID AHMED; RASIDI, MOHD HISYAMWayfinding challenges in crowded, unfamiliar environments pose significant safety and comfort risks for users, particularly in mass gathering contexts. During the 2019 Hajj pilgrimage, over 211,000 pilgrims became lost at Al-Mashaaer Al-Mugaddassah Metro stations, highlighting critical deficiencies in existing wayfinding systems that serve more than 2 million international visitors annually. This study aims to develop a wayfinding system model that enhances navigation efficiency in crowded contexts and unfamiliar environments by examining the specific case of Muzdalifah metro stations during Hajj. A mixed-methods approach was employed, collecting data through structured questionnaires distributed to Hajj pilgrims with prior metro station experience. From 394 questionnaires distributed, 271 valid responses were obtained (68.27% response rate). Data analysis was conducted using SPSS version 25, employing structural equation modeling to examine relationships between variables and assess model validity through reliability analysis, normality tests, and bootstrapping procedures. The study identified five critical factors significantly influencing wayfinding system efficiency: educational attainment, user expectations, information availability, routing strategies, and signage design. These factors demonstrated substantial impact on pilgrims' perception of congestion, which directly influenced their feelings of safety and comfort during navigation. The analysis revealed that pilgrims' demographic characteristics moderate the relationship between environmental factors and wayfinding effectiveness, with educational level showing the strongest influence on navigation success. The developed wayfinding system model provides a theoretical framework for improving navigation efficiency in crowded, unfamiliar environments. Practically, this research offers evidence-based recommendations for enhancing metro station wayfinding systems, potentially reducing pilgrim disorientation and improving crowd management. The findings contribute to wayfinding theory by establishing the mediating role of crowding perception between environmental factors and user experience in mass gathering contexts. This research supports Saudi Vision 2030's objective of improving Hajj services and has broader applications for transportation hubs and public spaces serving diverse, international populations.9 0Item Restricted EXPLORING DOMESTIC TOURISTS' SATISFACTION WITH HERITAGE DESTINATION ATTRIBUTES: A HOLSAT MODEL, CASE STUDY: HISTORIC JEDDAH, SAUDI ARABIA(UNIVERSITI SAINS MALAYSIA, 2025) Haressy, Abdullah Yahya; Suraiyati, Binti RahmanHistoric Jeddah, a UNESCO World Heritage Site, represents one of the most significant heritage tourism destinations in Saudi Arabia. Despite its cultural and historical importance, tourist satisfaction with Historic Jeddah has not been systematically examined, especially from the perspective of domestic visitors. This gap is critical, as understanding tourists’ expectations and experiences is essential for enhancing service quality, improving infrastructure, and sustaining the city’s competitiveness in the growing heritage tourism sector. The novelty of this study lies in the adaptation and application of the Holiday Satisfaction (HOLSAT) model to Historic Jeddah, integrating demographic analysis with a systematic assessment of expectation–experience gaps across cultural and historical appeal, accessibility and mobility, facilities and services, hospitality, and value-for-money. Data were collected through an online survey conducted between June and July 2025, yielding 421 valid responses from domestic tourists across the five regions of Saudi Arabia. Descriptive statistics profiled tourist demographics, frequency of visiting, and travel purpose, while paired-sample t-tests identified expectation–experience gaps. Correlation analysis and multiple regression were then employed to examine the influence of HOLSAT dimensions on overall satisfaction. Reliability testing confirmed strong internal consistency across all dimensions (Cronbach’s α > 0.88). The results show that overall satisfaction was positive, with cultural and historical appeal and hospitality exceeding expectations. In contrast, negative gaps were found in facilities & services and accessibility & mobility, particularly in toilet availability, disability access, and road signage. Regression analysis further revealed that experiences were stronger predictors of satisfaction than expectations, with hospitality emerging as the most influential factor, followed by cultural & historical appeal, while value-for-money had a mixed effect. The study contributes to tourism research by providing empirical evidence on how HOLSAT dimensions shape satisfaction in a Middle Eastern UNESCO heritage context, offering a framework that can be applied to similar destinations. Practically, the findings highlight the need for targeted improvements in infrastructure and pricing strategies, alongside sustained investment in heritage preservation and hospitality training. By addressing these areas, policymakers and tourism managers can enhance visitor experiences, strengthen repeat visitation, and support the long-term sustainability of Historic Jeddah as a world-class heritage tourism destination.36 0Item Restricted IMPACT OF SOCIO-CULTURAL FACTORS AND WORKPLACE INCLUSION ON WOMEN ENTREPRENEURIAL SUCCESS IN SAUDI ARABIA(Saudi Digital Library, 2025) DIBAS, AMANI MOHAMMAD; Alharath, AbdulazizWomen's entrepreneurship has emerged as a significant global phenomenon in the 21st century, particularly as women in developing countries increasingly participate in the workforce to support their families. Despite the progressive policy shifts and governmental initiatives aimed at empowering women entrepreneurs in Saudi Arabia, particularly epitomized by the ambitions of Vision 2030, a significant disjuncture persists between national aspirations and lived realities, especially concerning socio-cultural constraints that continue to impede women's entrepreneurial success. Therefore, this Study Is Aimed at Assess the Impact of socio-cultural factors and Workplace Inclusion on women entrepreneurial success in Saudi Arabia. the study intends to use SPSS-AMOS which is considered good to test the hypotheses rigorously. The findings reveal that social norms significantly negatively impact Saudi women's entrepreneurial success, while family support positively influences it. Surprisingly, workforce inclusion showed no significant impact, contradicting the initial hypothesis of a negative effect. The study recommend that attention should be focus on addressing negative social norms through campaigns and education, and strengthening family support systems given their positive impact. Further investigation into workforce inclusion's nuanced role is advised. Overall, targeted support programs are crucial to empower Saudi women entrepreneurs by navigating socio-cultural challenges and leveraging existing strengths.13 0