Saudi Cultural Missions Theses & Dissertations
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Item Restricted ‘The Legality of NATO Military Interventions: Balancing Collective Defense and International Law’(The University Of Edinburgh, 2024) Alanazi, Khalid; Neff, StephenNATO Military Interventions Legal Frameworks Collective Defense International Law North Atlantic Treaty Article 5 Non-Article 5 Operations Peace Enforcement Stabilization Missions 1999 Kosovo Intervention Humanitarian Intervention Responsibility to Protect (R2P) United Nations Charter Legality and Legitimacy Humanitarian Impact Global Peace and Security International Legal Standards Precedents in NATO Actions Humanitarian Outcomes and Consequences19 0Item Restricted Active Power Filters for Industrial Loads(University of Strathclyde, 2024-08) Alanazi, Khalid; Campos-Gaona, DavidHigh-power industrial loads, such as induction ovens and machine drives, frequently use uncontrolled rectifiers that introduce significant harmonic content into AC networks. This harmonic current can distort the voltage at the point of common coupling (PCC), negatively impacting other connected loads by reducing efficiency, increasing equipment wear, and potentially causing transformer saturation. Excessive heating and noisy operation in motors are further consequences. To mitigate these effects and improve overall system efficiency, distribution system operators (DSOs) may penalize customers generating high harmonic levels, incentivizing harmonic reduction measures. Active power filters (APFs) are designed to address these harmonics. They measure the load current, extract the harmonic and reactive components, and supply these back into the system to counteract the unwanted currents. APFs are categorized into series, shunt, and hybrid types. Series APFs inject voltage in series with the grid to maintain nominal load voltage during voltage sags or swells, while shunt APFs are parallel-connected to supply local reactive and harmonic components. Hybrid APFs combine active and passive elements for enhanced performance. APFs offer several advantages, including improved power quality, reduced thermal stress on electrical components, minimized electronic interference, and enhanced system efficiency. They adapt to changing harmonic currents in real-time, unlike passive filters that are tuned for specific harmonics and cannot adjust to varying loads. Passive filters, such as single-tuned, double-tuned, and high-pass filters, may require multiple units for comprehensive harmonic elimination, increasing cost and space requirements.13 0Item Restricted A Study of Pure and Surfactant-Stabilized Oil-Water Emulsions in Batch Separators(The University of Tulsa, 2024-07-17) Alanazi, Khalid; Mohan, Ram S.; Shoham, OvadiaUnderstanding the influence of mixing speed and volumetric water concentration (WC) on emulsion stability in batch separators, particularly pure (emulsifier-free) oil-in-water (O/W) and water-in-oil (W/O) emulsions, remains a significant challenge. Also, previously published models do not consider the effect of mixing speed on emulsion type. Therefore, this work proposes a unique strategy for incorporating the role of initial mixing speed and WC into several variables of the separation dynamic in batch separators. The technique was based on the framework developed by Jeelani et al. in 1999. According to comparisons made against literature data, the improved model was shown to capture the initial and later stages of the separation fairly well. Furthermore, it requires assumption of only one variable, ranging from 0.80 to 2.70, as opposed to the four variables required by Jeelani et al.'s (1999) original model. The study also carried out many experiments to understand the significance of mixing speed (600-2500 rpm), water salinity (0-60 g/L), water acidity (1.88-4.80 pH), and temperature (25-80°C) on mineral oil (ExxsolTM D110) and distilled water dispersion stability. Subsequently, the work considered dissolving 0.050% wt. of Tergitol 15-S-7 (T15S7) in the water phase and 0.050% wt. of Span® 80 (SP80) in the oil phase. Each surfactant was introduced separately. Data of surfactant-stabilized emulsions were gathered at mixing speeds of 800 rpm and 2500 rpm, iii temperatures of 25°C-80°C, and in the presence of monovalent salt (NaCl), divalent salt (CaCl2 and MgCl2), and their mixture. Unlike pure W/O emulsion, pure O/W emulsion was substantially impacted by mixing speed, water salinity, and water acidity. Indeed, the stability under these three conditions changed from a few minutes to over four hours. Although the increase in temperature accelerated the separation kinetic of the oil phase, it was shown to delay the initiating time of water separation and was overall ineffective as compared to water salinity and acidity. At WCs ≤ 50%, the increase in mixing speed from 800 rpm to 2500 rpm showed no visible effects on the volume of T15S7-stabilized emulsions (especially after a few hours of the separation process). At WCs ≥ 75%, however, the emulsion volume increased enormously with mixing speed. In the absence of salts, the increase in temperature showed no effects on 75% WC T15S7-stabilized emulsions for at least 4 hours. On the contrary, in the presence of salt, 70°C and 80°C temperatures resulted in immediate separation of T15S7-stabilized emulsions. Furthermore, in the presence of salts, 75% WC emulsions stabilized with SP80 showed full separation within a few seconds at 800 rpm. However, at 25% WC and 800 rpm, the SP80-stabilized emulsion was extremely stable, with or without salt. However, after increasing the mixing speed to 2500 rpm, both monovalent and divalent salts improved the stability of 25% WC SP80-stabilized emulsions. Furthermore, data of T15S7-stabilized emulsion (at 25% WC) showed less stability with salts. In summary, at 25°C, salt concentrations ranging from 1 to 60 g/L impacted the stability of pure O/W emulsions significantly, but not emulsions stabilized by SP80 or T15S7.66 0Item Restricted An investigation into 1-methyl-3-octyl imidazolium toxicity in the undifferentiated HepaRG cell line(Saudi Digital Library, 2023) Alanazi, Khalid; Wright, MattThe 1-Methyl-3-Octyl Imidazolium (M8OI) was recently detected in the environment using rat progenitor (B-13) cell lines in a toxicity screen. M8OI has subsequently been proposed as a potential trigger for Primary Biliary Cholangitis (PBC), an autoimmune liver disease. The HepaRG cells were used to investigate the M8OI toxicity because they are human progenitor like cells that can differentiate into both hepatocytes as well as cholangiocytes. In previous studies, undifferentiated HepaRG cells were shown to be relatively insensitive to M8OI toxic effects compared to B13 cells. This study aims to examine the insensitivity of undifferentiated HepaRG cells to M8OI. Increased medium glucose concentrations did not afford protection to undifferentiated HepaRG cells, in contrast to B-13 cells. Seahorse assay indicated that undifferentiated HepaRG cells consumed significantly less oxygen compared to B-13 cells when normalised for protein. Further, M8OI was less potent as an inhibitor of oxygen consumption in HepaRG cells compared to B-13 cells. This study also investigated whether undifferentiated HepaRG cells expressed CYP1A1, which could be capable of converting M8OI into non-toxic compounds. The results of this study indicated that undifferentiated HepaRG cells had negligible CYP1A1 activity although low levels were detectable after treatment with beta-naphthoflavone. These data suggest that undifferentiated HepaRG cells are less sensitive to M8OI toxicity compared to B-13 cells due to reduced reliance on mitochondrial oxidative phosphorylation combined with reduced sensitivity to M8OI inhibitory action on the electron transport chain. Expression of functional CYP1A1 activity was not responsible for reduced sensitivity to M8OI.23 0