Saudi Cultural Missions Theses & Dissertations
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Item Restricted ADOPT: An environmentally-friendly system for alerting drivers to occluded pedestrians traffic(Old Dominion University, 2024-08) Alali, Abrar; Olariu, StephanThe emergence of sensing technologies and vehicular communications has brought significant opportunities for enhancing pedestrian safety on city streets. However, existing solutions rely on costly technologies such as computer vision and trajectory prediction to detect crossing pedestrians, while they have limits in detecting pedestrians who are occluded by parked cars. Despite the presence of collaborative perception by surrounding vehicles and infrastructure, there is a notable absence of incorporating existing parked cars themselves due to their insufficiency in detecting pedestrians and communicating with other cars while they are turned off. Furthermore, accommodating pedestrians on streets has been linked to an additional cost to the environment. This cost is due to the fluctuations in the speed of the car to avoid collisions with pedestrians, which increases fuel consumption and CO2. We first propose to enlist the help of cars parked along the sidewalk to detect and protect crossing pedestrians. In support of this goal, we propose ADOPT: an Environmentally-friendly system for Alerting Drivers to Occluded Pedestrian Traffic. ADOPT lays the theoretical foundations of a system to use parked cars to detect and protect occluded pedestrians. We cope with the resource constraints in parked cars by utilizing short-range and low-power radio frequency sensors to detect pedestrians who also transmit radio signals from energy-harvesting wearables. To estimate fuel consumption and CO2 of cars, we found that the existing estimating approaches for user-specific requirements are not suitable for our goal. We overcome this limitation by using a simple version of the energy demand model knowing the most suitable powertrain efficiency. Thus, in this dissertation, we evaluate the vehicle energy demand model by testing several powertrain efficiencies. This allows us to accomplish our next task in this dissertation. Next, we propose speed reduction schemes based on studying possible scenarios for midblock crossing. In these scenarios, the approaching car receives, in advance, caution messages about crossing pedestrians from ADOPT system. We show that these schemes reduce the fuel consumption and CO2 emissions of approaching cars. With this, we show how ADOPT is an environmentally friendly system without compromising the safety of midblock pedestrians by utilizing parked cars along the street.26 0Item Restricted RedEye-1: A New Short-Wavelength Infrared Hyperspectral Imager for Atmospheric Observation(University of Sydney, 2024-05-22) Alsalem, Naif; Cairns, Iver H.; Betters, Christopher H.; Leon-Saval, Sergio G.Efficient monitoring of atmospheric constituents, particularly methane (CH4) and carbon dioxide (CO2), is of paramount importance in addressing the challenges posed by global warming and its repercussions for climate change. Presently, the field of hyperspectral imaging for atmospheric measurement/reconnaissance is characterised by two predominant categories: large-scale, high-resolution systems and their miniaturised, lower-resolution counterparts. Additionally, the development of hyperspectral systems, particularly in the short-wavelength infrared (SWIR) and beyond, often entails substantial costs due to the necessity of specialised optics and dedicated detectors. In response to these challenges, this thesis presents a compromise solution, RedEye-1, a compact, cost-effective SWIR hyperspectral imager designed with off-the-shelf optical components to bridge the gap between these existing paradigms. RedEye-1 operates within a spectral range of 1588-1673 nm, offering a relatively high spectral resolution of approximately 0.5 nm. This capability, combined with a Ground Sampling Distance (GSD) of roughly 2.4 metres from an altitude of 3 kilometers, positions RedEye-1 as a suitable tool for the measurement and quantification of CH4 and CO2 within the atmospheric layer of the Earth. The development process of RedEye-1 encompassed several stages, including design, construction, assembly, spectral and radiometric calibration, as well as ground and airborne tests. In particular, RedEye-1 embarked on its initial airborne reconnaissance mission on a light aircraft, providing new data that confirm its successful operation and valuable insights into the challenges encountered during airborne operations. Using an inversion model and a Line-by-Line radiative transfer algorithm, the ground-based single path measurement near 1645 nm estimated the CH4 concentration to be around 1912 ppb, indicating a reduction of approximately 5 ppb compared to the standard atmospheric CH4 level. However, the airborne double-path measurement at the same wavelength yielded a higher concentration of approximately 5229 ppb, implying significant CH4 emissions from the coal mine flown over.17 0Item Restricted CO2 and Greenhouse Gas Emissions and their effect on Global Land Temperatures Using Machine Learning Models(University of Exeter, 2024-03-04) Alharbi, Naif; Siegert, StefenCO2 and Greenhouse Gas Emissions and their effect on Global Land Temperatures Using Machine Learning Models26 0Item Restricted Study on Reducing Dioxide Carbon Emissions of Rubber from Modified Asphalt Materials(Saudi Digital Library, 2023-08-15) Alsharari, Fawaz; Fangyuan, GongThe construction of new asphalt pavements has resulted in the release of greenhouse gases into the atmosphere. However, recent advancements have introduced products like Sasobit®, which can lower asphalt viscosity at lower temperatures compared to conventional mixtures. This temperature reduction has the potential to effectively reduce greenhouse gas emissions. The objective of this study was to evaluate the emissions reduction potential of warm mix asphalt (WMA) compared to hot mix asphalt (HMA) produced at higher temperatures, as well as to assess any improvements in material properties. Additionally, the study aimed to determine the economic benefits associated with producing mixtures at lower temperatures. To conduct the study, emissions testing was performed on pure asphalt and asphalt mixes. Samples of HMA and WMA were mixed and compacted to evaluate material properties. Three different mixes were tested: HMA with 7.3% asphalt, WMA with 7.3% asphalt and 1% Sasobit® (by mass of asphalt), and WMA with 6.8% asphalt and 1% Sasobit® (by mass of asphalt). Emission tests were carried out using Drager test equipment, including flasks, ovens, a Drager pump, and Drager tubes. The Drager pump required 10 full strokes to measure carbon dioxide (CO2), and the concentration of CO2 in parts per million (ppm) was indicated by the color change in the tube. Preliminary testing was conducted on emissions from pure asphalt to establish a testing procedure since no existing standards were available. The emissions testing involved approximately sixty grams of WMA and HMA asphalt mixtures, as well as approximately twenty-five grams of pure asphalt. The three asphalt mixtures were subjected to tests under controlled conditions and aged to evaluate their material properties according to standards set by the American Society for Testing and Materials. The tests included analysis of bulk specific gravity, theoretical maximum density, and indirect tensile strength to determine volumetric and mechanical properties. The volumetric properties assessed were the percentage of air voids, adsorption, and effective asphalt content. After comprehensive testing and analysis of the three asphalt mixes, it was concluded that the addition of Sasobit® as an additive in WMA yielded positive results. The changes in material properties led to stronger and more durable asphalt mixes, as well as an extended paving season. By incorporating Sasobit®, the production temperature of HMA could be lowered by 20°C, potentially resulting in a reduction of up to 43.9% in annual carbon dioxide emissions from the asphalt industry. This reduction VI encompasses emissions from both fuel usage and the asphalt materials used in hot mix asphalt production. Furthermore, the lower temperature requirement for Sasobit® asphalt mixes could generate energy cost savings exceeding $69 million. The environmental impact of utilizing Sasobit® asphalt mixes in the industry is significant. By reducing greenhouse gas emissions from asphalt mixing materials and production energy, it has the potential to contribute to the improvement of the Earth's atmosphere. The study estimated that annually, the use of Sasobit® could prevent 3.774 million tons of carbon dioxide emissions from asphalt mixing materials and production energy. Over a span of ten years, this would amount to preventing 37.74 million metric tons of carbon dioxide emissions. It is crucial for the asphalt industry to prioritize its environmental impact, and the incorporation of Sasobit® into asphalt mixes represents a promising step in that direction3 0Item Restricted Techno-economic Analysis of the Impurity Impact on the CO2 Transportation(Saudi Digital Library, 2023-10-17) Alfaleh, Saleh Abdullah; Chalmers, HannahThis dissertation conducts a technical and economic analysis of the impact of the impurities on the CO2 transportation in the Humber cluster over a distance of 364.5 km through onshore pipelines. This analysis aims to give an indication of whether transporting relatively impure CO2 to a shared conditioning unit at the gathering hub is more economically viable than having lots of individual conditioning facilities at the source. The analysis includes conditioning facilities after the capture process and pipeline design. Different impurity level scenarios, including major non-condensable gases O2, Ar, and N2 with CO2, were investigated. In the technical analysis the impact of impurities on the thermodynamic properties of CO2 stream including VLE region, density, compressibility factor, viscosity and speed of sound were examined. The cost model includes CAPEX, OPEX of the conditioning units and pipelines and the electricity cost influenced by the conditioning unit. The impact on power demands and pipeline diameters is examined, revealing a correlation between elevated impurity levels and raised overall power consumption as well as an increase in pipeline diameter. Several key conclusions have been drawn to demonstrate the cost effect, showing an increase in the low CO2 purity scenario compared to the ideal scenario of 21.5%. A sensitivity analysis shows the economic visibility of shared conditioning units with varying electricity costs.25 0