Browsing by Author "Alanazi, Ahmed"

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Advanced Nanomaterial Composites for Enhanced Photocatalysis and Sensing
(Saudi Digital Library, 2023-11) Alanazi, Ahmed; James, Rice
Recent advances in nanostructuring techniques have contributed to the field of plasmonics. In current research, plasmonic plays an important role in sensing, including surface enhanced Raman spectroscopy (SERS). The fabrication of platforms for optical sensing has traditionally been carried out using costly techniques requiring specialized equipment. These techniques require precious metals, which have limitations in biocompatibility, high environmental impact, cost, and availability. Semiconductors are used in SERS since they provide enhanced Raman signals through their unique optical and electronic properties, allowing for tunability and reproducibility. Their stability and compatibility with various technologies render them valuable substrates for highly sensitive molecular analysis. Furthermore, their additional benefits include cost-effectiveness, recyclability, self-cleaning properties, and flexibility, which make them suitable for potential integration with other technologies. Even though semiconductor-based SERS have been the subject of numerous promising studies, current state-of-the-art designs are largely restricted due to their lower signal enhancements. New designs for SERS substrates are crucial to overcome some limitations and improve the performance of SERS. Existing designs may have limitations in terms of sensitivity, reproducibility, scalability, or compatibility with specific molecules or applications. The aim of the thesis is to investigate the combination of semiconductors and plasmonic nanomaterials in order to develop new designs implementing simple, cost-effective, and environmentally friendly strategies. The combination of plasmonic nanomaterials with semiconductors has great potential for sensing and photocatalysis. This thesis is divided into nine chapters: In Chapter 1, a brief description of Raman scattering and molecular dynamics is presented, as well as Raman-active modes selected based on vibration spectra, light-driven electronics. In the following section, examples are provided of how Raman spectroscopy is used in modern research. Following this, a brief overview of SERS is provided, including electromagnetic and chemical enhancements as well as effects related to wettability. Lastly, the chapter discusses photocatalysis mechanisms and applications, such as chemical oxidation reactions and self-cleaning photocatalysis. Chapter 2 provides an overview of the primary strategies which can be utilized in the design of optical sensing platforms for SERS. Several material classes are discussed as well as their properties that make them useful for chemical detection. First, the primary processes involved in the production of platforms fabricated from precious metals will be briefly reviewed. This method will also be discussed in terms of its advantages and disadvantages. In the following section, alternative semiconductor materials are examined; these materials have the advantage of being biocompatible and easy to fabricate. Several subgroups of semiconductor materials that have been demonstrated to be effective at enhancing optical signals are discussed following an introduction to the two primary categories of semiconductor materials - organic and inorganic. In Chapter 3, a brief overview is presented of the major spectroscopy and microscopy techniques utilized to explore the optical properties and morphology of the manufactured substrates investigated in this thesis, along with the methods utilized to analyze the data. The analysis methodology and experimental specifics of how the measurements were conducted are described in some depth in the text, which presents the overall ideas underlying the analysis. In Chapter 4, investigate the photocatalytic potential of transition metal chalcogenides (TMCs) cadmium sulfide (CdS) when coupled with plasmonic nanostructures. The synthesis of dimercaptoazobenzene (DMAB) from p-amino thiophenol (PATP) was demonstrated by the super bandgap irradiation of a silver nanowire (Ag NWs) and cadmium sulfide composite for PATP. For plasmonic photocatalysis applications, our findings indicate that cadmium sulfide can serve as an alternative to semiconductors, such as titanium dioxide. In Chapter 5 a combination of conducting polymers such as P3HT (poly-3-hexylthiophene) and PcBm (phenyl-C61-butyric acid methyl ester) with plasmonic nanomaterials is demonstrated to enhance Raman scattering spectroscopy signals up to five-fold and to support the oxidation of target molecules by supporting the charge transfer. The purpose of this chapter is to demonstrate how conducting polymers can be used as semiconductor platforms for the development of plasmonic catalysis and sensing techniques. Chapter 6 describes the development of nanocomposites consisting of metals and organic conducting semiconductors, which have the potential to provide a flexible, lightweight platform for plasmon-based sensing. The purpose of this chapter is to demonstrate the use of super band-gap irradiation to provide plasmon excitation and irradiation to remove analytes from a polymer-plasmonic composite based upon the conducting polymers P3HT and PCBM, as well as to support plasmon-enhanced spectroscopic detection. Our research demonstrates that such a polymer-plasmonic composite is an effective self-cleaning system for use as a reusable optical sensing substrate. In Chapter 7, plasmon active metal nanostructures and semiconductors are described as nanocomposites that support catalytic activity. As discussed in this chapter, transition metal dichalcogenides such as MoS2 when combined with metal oxides such as ZnO have the potential to control charge states in plasmonic nanomaterials. The objective of Chapter 7 is to demonstrate the possibility of controlling plasmonic reactions through the careful selection of semiconductors. In Chapter 8, we present a framework consisting of silver nanoparticles (Ag NPs) on Mg-doped lithium niobate surface. The activation of charge transfer processes on this substrate under white light irradiation is demonstrated to support the oxidation of compounds such as p-amino thiophenol. The purpose of this chapter is to highlight the use of doped lithium niobate materials as semiconductor platforms for plasmonic catalysis. Conclusions and future work are discussed in Chapter 9.
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An Exploration of the Acceptance of Telerehabilitation in Saudi Arabia: Physiotherapists' and Patients' Perspectives
(University of Nottingham, 2024-01-29) Alanazi, Ahmed; Wharrad, Heather
Background: Providing long-term treatment and monitoring for patients, especially those with neurological conditions, requires resources which are not always available. Consequently, finding innovative solutions that can ease the financial and physical burden of chronic conditions is essential. Telerehabilitation offers a potential solution to this challenge, and it was widely used during the COVID-19 pandemic, when face-to-face rehabilitation services could not be provided. However, despite its clinical effectiveness, previous studies suggest that its application may be impeded by users’ concerns, and an inadequate understanding of the practical implications of the discipline. The number of people with chronic disabilities in the Kingdom of Saudi Arabia (KSA) exceeds one million, and these patients require regular sessions with physiotherapists; however, accessing rehabilitation services can be difficult and costly, especially for those in rural or remote areas. Although telerehabilitation was used in the Saudi healthcare system before the pandemic, no formal framework to support its implementation exists and the potential barriers to its wider adoption in the country have not been clearly identified. As a result, this study explores the acceptance of telerehabilitation among physiotherapists and patients with neurological conditions in KSA and proposes a potential strategy for its nationwide implementation which takes account of the country’s large geographic area and its socio-religious context. Methods: This study adopts a pragmatic philosophical paradigm and employs the Technology Acceptance Model (TAM) and the Unified Theory of Acceptance and Use of Technology (UTAUT) models to identify the factors which influence Saudi physiotherapists’ and patients’ acceptance of telerehabilitation. It also utilises Q methodology to gather and analyse the data, introducing a novel online approach to data collection in response to the limits on face-to-face engagement as a result of the pandemic. Results and discussion: The physiotherapist participants viewed telerehabilitation as beneficial, particularly for patients in rural or isolated areas, but they expressed concerns about data security, and the lack of training and technical support. The use of Q methodology enabled them to be categorised into three attitude-based groups: Advocates, who supported telerehabilitation for its cost-effectiveness; Pragmatists, who were open to healthcare technology but emphasised the need for better patient understanding of the uses of telerehabilitation; and Hesitants, who were uncertain and concerned about missing important clinical information. The patients with MS had varied perspectives, appreciating potential benefits, such as cost savings, but expressing concerns about data security and highlighting the lack of support from family and friends as a potential barrier. These patients were also categorised into three groups: Supporters, who recognised telerehabilitation's benefits but had concerns about a lack of suitable space at home and would prefer to be treated by a physiotherapist of the same gender; Rationalists, who accepted telerehabilitation's potential benefits but who thought more resources were required in order to accept it; and Resisters, who questioned its effectiveness over face-to-face rehabilitation. Barriers to telerehabilitation acceptance included the lack of facilitating conditions, such as training, guidelines, and equipment, individual differences such as age, gender knowledge, digital literacy, and medical conditions, and social influence, such as lack of support and encouragement from physiotherapists and family and friends to use telerehabilitation. These findings informed the development of a logic model for a strategy to implement telerehabilitation in KSA, which considers religious and cultural beliefs in KSA, and addresses the barriers identified above. The model sets out the desired outcomes, necessary inputs, and activities for physiotherapists, patients and healthcare services. It also lists the short-term, medium-term, and long-term outputs, the assumptions on which the model is based, and the external factors which might affect its implementation, including the rapid rate of social change in KSA. Conclusion: This study fills a gap in the literature by examining users' perceptions of telerehabilitation in KSA and identifying the barriers to its acceptance among two key stakeholders groups. The logic model contributes to society by outlining a strategy for the implementation of telerehabilitation in KSA, and, potentially, in other countries which share its cultural and religious values. The study also contributes to Q methodology by demonstrating an innovative method for online data collection and evaluating its effectiveness. In addition, the use of Q methodology in combination with the TAM and UTAUT models provides a methodology to assess user acceptance of healthcare technologies which could be used in other contexts. As such, the findings of this study are of immediate value to policy makers and healthcare providers in KSA, but they also have wider implications. Future research in the Saudi context should focus on the feasibility of the proposed strategy, including cost-benefit analyses and practical trials, and exploring perceptions in other rehabilitation fields, such as occupational and speech therapy.
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CENTRALIZED FOUR-LEGGED ROUNDABOUT CONTROL FOR AUTOMATED VEHICLES FLOWS.
(University of Akron, 2024) Alanazi, Ahmed; Yi, Ping
Abstract This research explores the application of Centralized Roundabout Control (CRC) to enhance the effectiveness of traffic at roundabouts under different traffic volumes. Although advantageous in practice at low traffic levels, conventional roundabouts often fail to sustain vehicle flow at higher demand levels, resulting in experiences such as queuing, increased waiting periods, increased fuel costs, and longer distances traveled. For these reasons, the CRC system was developed, and it is a traffic control solution that enhances roundabouts performance by orchestrating the entry of vehicles to reduce the waiting time and advance the traffic flow within the roundabouts. This research designed traffic at three volumes: low, medium, and high. It also used both MATLAB and VISSIM software for simulations. These simulations aimed to evaluate the performance of the CRC system in the current traffic control model, focusing on measurable performance factors such as waiting time, travel time, delays, bath throughput, fuel consumption, and stop time. The purpose of the MATLAB simulations was to measure the travel and waiting times of the vehicles crossing the roundabout. The results indicated that the application of the CRC system would lead to a reduction in the waiting and travel times for all the traffic volumes. For waiting time, the reductions were indicating that the CRC system can manage traffic even during peak hours. Travel times were also improved, indicating the practical ability of the CRC system to deal with traffic jams, enabling easy vehicle flow. These results indicate the ability of the CRC system to enhance traffic management systems by improving the drawbacks associated with the use of roundabouts in traffic. For the VISSIM simulations, five cases were reviewed: delay time, throughput and fuel consumption. All of the measures improved dramatically with the existence of the CRC system. vi For example, for Delay time, the reductions were the case with traffic volume, thus indicating the ease with which the CRC systems can handle both moderate and heavy traffic without undue delay. Throughput, or the vehicles number that were able to cross over the roundabout went , thus turning out again proving the system’s ability to foster the roundabout performance better by alleviating the problem of over congestion. There was also a reduction in the use of fuels, which is very important for commercial and ecological reasons, for example, in the CRC model. These reductions imply depreciation in the fuel wasted through proper traffic management to enhance efficiency and reduce the time for the vehicles to idle.
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Characterization of trace metals in E-cigarettes
(2023-11) Alanazi, Ahmed; Macphee, Donald; Mccue, Alan
Electronic cigarettes (e-cigarettes) are devices that are designed to replace conventional cigarettes (Hartmann-Boyce et al., 2021). E-cigarettes are electronic devices that heat a liquid to produce a vapour for inhalation by users. They were invented to provide smokers with a safer and cleaner way to inhale tobacco and to enable them to cease their smoking habit. These types of cigarettes are considered to be safer than conventional cigarettes because they do not contain harmful tobacco; however, like conventional cigarettes, most contain nicotine – which is toxic and addictive – and the presence of other hazardous components is inherent in their design (Gaur & Agnihotri, 2018). The e-cigarette liquids, atomisers and aerosols are major sources of trace heavy metals, also known as trace elements (TEs), which pose risks to human health at certain concentrations in the body. TEs such as tin (Sn), nickel (Ni), aluminium (Al), chromium (Cr) and cadmium (Cd) leak from the core assembly (Jaishankar et al., 2014), while others such as lead (Pb) and zinc (Zn) are present in the liquid. Although some of these metals are essential elements at low doses, they are toxic at high concentrations, especially when they are inhaled. They are potentially carcinogenic and have been linked to the development of fatal health problems such as anaemia (US Centers for Disease Control and Prevention [CDC], 2022). Thus, although e-cigarettes are characterised as safer than conventional cigarettes, they can still pose a threat to human health. When a user smokes a conventional cigarette, the harmful elements in tobacco smoke enter the user’s nervous system (heart and vital organs) within a few seconds of the initial inhalation and subsequently affect many parts of the body. However, inhalation of vapourised electronic cigarette liquid (e-liquid) is becoming increasingly popular. This vapour is generally considered safer than the contents of conventional cigarette smoke. The active components of e-cigarettes are mixtures of propylene glycol (PG) and vegetable glycerine (VG) that contain different proportions of nicotine and flavouring (Stratton et al., 2018). The two most harmful components of tobacco smoke, tar and carbon monoxide, are absent from e-cigarettes, which are subject to strict safety and quality regulations. However, e-cigarettes still pose risks because they are only slightly safer than conventional cigarettes (Uchiyama et al., 2020). This research project was designed to investigate the source of TEs in e-cigarettes. The identified sources included the metal cover, inner clamp and wick. Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was utilised to determine the levels at which various elements were present in e-cigarette samples. ICP-MS in single particle mode was used to determine the presence of nanoparticles. Due to the solubility properties of the e-liquids, many e-cigarettes contain dissolved TEs, such as Ni, Pb and Zn. The concentrations of VG and PG vary according to the e-liquid brand, so the proportions of TEs vary among e-cigarettes. There is a close relationship between a high concentration of VG and a high amount of TEs in e-cigarettes. In this project, increased ratios of VG to PG resulted in increased concentrations of TEs in the e-liquids. Parameters of the e-cigarettes, such as power and number of puffs, were studied and were discovered to influence the concentrations of TEs found in the e-liquids.
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The Validity and Challenges of Third-Party Funding in the Saudi Arbitration Framework
(Washington University, 2024-05-21) Alanazi, Ahmed; Reeves, James
Third-party funding (TPF) is a new concept in which a third-party funds one of the disputing parties for potential share outcomes while the funded party is not obligated to repay the funds if the case is unsuccessful. In recent decades, the TPF has become more prominent for dispute parties who have faced financial obstacles to access to justice. However, the validity of the TPF agreements in Saudi Arabia remains to be determined. As the ruler of Saudi laws, Shariah prohibited agreements involving gharar (uncertainty) and usury as public policy concerns. Therefore, to break the silence surrounding TPF, this dissertation examined the validity of TPF from Shariah and Saudi perspectives. Consequently, the dissertation concluded that TPF complies with Shariah, based on the Muzara'ah partnership model, with sharing risks. This dissertation also introduces a Saudi roadmap for a TPF framework, which recommends the following (third-party funding arrangements in the Muzara'ah model comply with Saudi public policy. 2) Amendments to Saudi arbitration law require mandatory TPF disclosure to avoid conflicts of interest. 3) A code established by a supervisory body to monitor the TPF’s confidentiality and ethical practices in Saudi Arabia.
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