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Proton Conductivity Studies of Zirconium Silicate/Ionic Liquids Membranes for PEM Fuel Cells Applications
No full textA Master of Science thesis in Chemical Engineering by Rana Muhammad Nauman Javed entitled, “Proton Conductivity Studies of Zirconium Silicate/Ionic Liquids Membranes for PEM Fuel Cells Applications”, submitted in December 2020. Thesis advisor is Dr. Amani Al-Othman and thesis co-advisor is Dr. Paul Nancarrow. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).This work reports the synthesis of a novel, high-temperature composite membrane for proton exchange membrane (PEM) fuel cells. High-temperature operation (> 100oC) is preferred in PEM fuel cells as it results in better water management and an enhancement to the overall kinetics of fuel cells’ electrodes. The current state of the art Nafion membrane is not suitable for high-temperature operation as their proton conductivities decline drastically. Hence, a novel Nafion-free membrane, based on zirconium silicates (ZrSi) and ionic liquids (ILs) is described in this thesis. Proton-conducting ZrSi/IL composite membranes were synthesized via precipitation of ZrSi/IL within the pores of polytetrafluoroethylene (PTFE) at room temperature. Seven different ILs were investigated to produce ZrSi/IL modified materials with ILs content ranging from 0.56% to 32% by mass. Significant enhancements in proton conductivities were observed upon the addition of the IL to ZrSi. Electrochemical impedance spectroscopy measurements showed proton conductivity values in the range of 0.1-0.2 S/cm, exceeding that of the Nafion membrane. The modified ZrSi/IL samples were further investigated by thermogravimetric analysis (TGA), scanning electron microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), and energy-dispersive X-ray spectroscopy (EDX). TGA analysis of the modified ZrSi/IL materials demonstrated an approximately 20% weight loss at around 500°C . Water uptake analysis indicated that the new composite membrane could hold more than 50% by weight of water. SEM analysis showed the changes in particles' morphology of the modified ZrSi/IL. The interactions of ILs with ZrSi were studied using FTIR & XRD. Changes in the ZrSi/IL crystalline structures in comparison with pure ZrSi were observed. The samples processed at a high-temperature (200°C ) and exhibited a high proton conductivity in the order of 0.001 S/cm. Thus, the ZrSi/IL membranes reported in this work are very promising as proton conductors for high-temperature fuel cell applications.College of EngineeringDepartment of Chemical EngineeringMaster of Science in Chemical Engineering (MSChE
Data Embedding and Extraction in Scrambled Video using Machine Learning
No full textA Master of Science thesis in Computer Engineering by Afaf Eltayeb Mohamedelbagir Ahmed entitled, “Data Embedding and Extraction in Scrambled Video using Machine Learning”, submitted in December 2020. Thesis advisor is Dr. Tamer Shanableh. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).Data embedding in videos and images has various important applications such as digital rights management (DRM), content authentication, copyright protection, error resiliency and concealment as well as law enforcement. With the high possibility of illegal access and unauthorized content manipulation in shared storage platforms such as cloud data centers and with the risk of encountering different types of attacks during network transmission, videos and other sensitive data are usually transmitted and stored in an encrypted form. Accordingly, the need for data hiding techniques that operate directly on the encrypted video domain has emerged. This work proposes a novel data hiding scheme in encrypted video streams where scrambling and data embedding are performed simultaneously at the encoder side by rotating the motion vectors of the cover video. Then a machine learning solution is proposed at the decoder side to classify the motion vectors to rotated/ unrotated, extract the hidden information bits and reconstruct the original cover video. A sequence-dependent approach is applied where the first part of the video is used for training and model generation. The proposed system is composed of two phases: firstly, the training phase where the model is trained to distinguish between the correctly reconstructed macroblocks and the macroblocks reconstructed using rotated motion vectors. Secondly, the testing phase in which the trained model is applied to identify which of the candidate macroblocks are the ones associated with the true motion vectors. Once the true motion vectors are identified, they are compared to the ones received in the bit stream and thus the embedded bits are extracted, and the video is reconstructed. Experiments are conducted on a number of well-known video sequences after compressing them once with the Moving Pictures Expert Group-2 video codec standard and then with the High-Efficiency Video Coding standard. A detailed analysis is provided based on the macroblock type, the number of motion vectors and the type of the encoding sequence. Lastly, the proposed solution is evaluated in terms of classification accuracy, embedding capacity and reconstruction quality.College of EngineeringDepartment of Computer Science and EngineeringMaster of Science in Computer Engineering (MSCoE
Fluorescent aminal linked porous organic polymer for reversible iodine capture and sensing
No full textA novel triazene-anthracene-based fuorescent aminal linked porous organic polymer (TALPOP) was prepared via metal free-Schif base polycondensation reaction of 9,10-bis-(4,6-diamino-S-triazin2-yl)anthracene and 2-furaldehyde. The polymer has exceptional chemical and thermal stabilities and exhibit good porosity with Brunauer–Emmett–Teller surface area of 401 m2 g−1. The combination of such porosity along with the highly conjugated heteroatom-rich framework enabled the polymer to exhibit exceptional iodine vapor uptake of up to 314 wt % and reversible iodine adsorption in solution. Because of the inclusion of the anthracene moieties, the TALPOP exhibited excellent detection sensitivity towards iodine via forescence quenching with Ksv value of 2.9 × 103 L mol−1. The cost effective TALPOP along with its high uptake and sensing of iodine, make it an ideal material for environmental remediation
Scale-Up of Self-Regenerating Semi-Batch Adsorption Cycles through Concurrent Adsorption and Reduction of Cr(VI) on Sheep Wool
No full textA previous publication by our group reported that adsorption of Cr(VI) on sheep wool reached 99% when allowed a long residence time, with concurrent reduction to Cr(III). In this study, the process was scaled up by optimizing a pilot plant based on semi-batch adsorption cycles. This yielded Cr(III), which is about 300 times less toxic than Cr(VI), and can be precipitated using lime at high pH. Since the reduction step is slower than the adsorption one, an adsorption column was designed to perform semi-batch operation cycles, whereby the extended “off cycle” allows reduction to take place. Since reduction of Cr(VI) frees active sites on wool, the plant acts in lieu of in situ regeneration, accompanied by additional adsorption of Cr(VI). The results show that 97% of the column efficiency can be recovered within 24 h of “off cycle”. Wastewater from a local electroplating industry was treated by this method with high removal of Cr(VI), reaching the limit permitted by environmental standards. This study also reveals that typical concentrations of heavy metals, present in wastewater produced from electroplating, had no substantial antagonistic interference with Cr(VI) adsorption
Assessment of Inventory and Transportation Collaboration in a Logistics Marketplace
No full textA Master of Science thesis in Engineering Systems Management by Saif Mohammad Shahid entitled, “Assessment of Inventory and Transportation Collaboration in A Logistics Marketplace”, submitted in March 2020. Thesis advisor is Dr. Malick Ndiaye. Soft copy is available (Thesis, Approval Signatures, Completion Certificate, and AUS Archives Consent Form).The globalization of businesses and the consequent competition introduce significant pressures on logistics systems. One such key demand on the role of logistics within organizations is the increased emphasis on time-based competition, i.e. the speedy manufacture, delivery to markets and the servicing required, as a result of increasing dependence on the ability of organizations rapidly and efficiently to deliver customer adapted products worldwide. The growing need for transparent, flexible, and easily adjustable logistics services has fostered the creation of digital brokerage platforms that match a variety of logistics demands with supply, widely known as an Electronic Logistics Marketplace (ELM). In this thesis, a comparative study was conducted for three distribution strategies with different levels of inventory collaboration. The Multi-Depot Vehicle Routing Problem (MDVRP) with supply and demand constraints were formulated for each strategy, and the mathematical models thus created were tested using random datasets generated on varied levels of customer dispersion. It was determined that the model representing the strategy of full inventory and distribution collaboration resulted in the least cost in all cases with an average savings of 76.70% as compared to the model with no collaboration. Since General Algebraic Modeling System (GAMS) was limited to small-sized problems for the models, an adaptation of the Variable Neighborhood Search (VNS) metaheuristic was developed and coded using C++ programming language. The heuristic was tested on several datasets, and had a deviation of 2% - 8% from the optimal solutions. The algorithm was further analyzed by testing larger sets, and it returned solutions for 90 nodes within 3200 seconds. Furthermore, a sensitivity analysis was conducted to assess the effect of changing some key input parameters on the total logistics costs. The input parameters were changed one at a time in a one-way sensitivity analysis study, and the effect of parameters’ variation on the total logistics cost was observed. Overall, the most influential inputs are the number of customer nodes, error in forecasted demand, last-mile cost per km, and vehicle capacity.College of EngineeringDepartment of Industrial EngineeringMaster of Science in Engineering Systems Management (MSESM
Combining Saliency with Prediction for Endoscopic Diagnosis
No full textA Master of Science thesis in Electrical Engineering by Mahmoud Rezk entitled, “Combining Saliency with Prediction for Endoscopic Diagnosis”, submitted in May 2020. Thesis advisors are Dr. Usman Tariq, Dr Abhinav Dhall and Dr Hasan Al Nashash. Soft copy is available (Thesis, Approval Signatures, Completion Certificate, and AUS Archives Consent Form).Healthcare sector has advanced tremendously in the past few years. With the advancement in technology, many image diagnostic techniques have been introduced to help doctors in identifying diseases and abnormalities inside the human body. However, the increase in population and access to affordable healthcare have increased the patient population significantly, which requires a bigger infrastructure in medical diagnostics. The demand and supply imbalance of expert doctors in the field had led to the increase in healthcare bills. As a solution to the scarcity problem, one of the advancements that has been introduced to this sector is automated diagnostics using artificial intelligence (AI). The automated systems are made to help doctors in two ways. Firstly, they decrease the time required by the doctor to diagnose the patient and, secondly, they act as a second layer of diagnostic verification. This thesis aims to automate the classification of endoscopic images to eight disease and non-disease classes using a deep network architecture that would detect the salient region and classify the images accordingly. This thesis further studies the effect of jointly performing both tasks on the overall quality of attention masks and the classification results. The automated system is achieved by concatenating a U-net architecture to a dense-net architecture to jointly predict the salient medical masks and classify them to their respective classes. Furthermore, the automated system proved that medical image masks can be achieved by transfer learning the knowledge learned from natural images. Additionally, jointly predicting the masks and reusing the masks for classification demonstrated that the joint behavior would increase the classification accuracy.College of EngineeringDepartment of Electrical EngineeringMaster of Science in Electrical Engineering (MSEE
Investigation of Friction Stir Back Extrusion
No full textA Master of Science thesis in Mechanical Engineering by Obadah Mosbah Al-Jarrah entitled, “Investigation of Friction Stir Back Extrusion”, submitted in January 2020. Thesis advisor is Dr. Mohammad Nazzal and thesis co-advisor is Dr. Bassil Darras. Soft copy is available (Thesis, Approval Signatures, Completion Certificate, and AUS Archives Consent Form).Friction Stir Back Extrusion (FSBE) is a new bulk deformation manufacturing process that utilizes severe plastic deformation to force the processed material to produce a tubular shape. To date, most of the research conducted in the field of FSBE investigates the mechanical behavior of the produced tubes without paying enough attention to the temperature history, strain rates or the material flow during deformation. In this work, a multiphysics thermomechanical model based on the coupled Eulerian Lagrangian approach was developed to simulate the FSBE process and investigate the material flow, strains, strains rates, grain size and temperature history in the formed tube during deformation. The numerical model accounts for large plastic deformation, heat generation due to friction and plastic deformation, tool-workpiece and die-workpiece mechanical and thermal interaction to accurately simulate the FSBE process. FSBE experiments for Mg AZ31 alloy were conducted to validate the numerical FSBE model. It is shown that the reactive body force in the principal loading direction and the temperature history in the die obtained from numerical modeling agree well with experiments. The numerical results show that strain rates in the range of 70 s ˉ¹ were attained at the inner surface of the formed tubes. The maximum temperature in the workpiece reaches 600 °C with no signs of material melting. Different material flow patterns were observed in the formed tube during deformation. The material in the central region of the cylindrical workpiece moves in a spiral motion with significant rotation while the material near the outer surface of the workpiece moves in a linear path.College of EngineeringDepartment of Mechanical EngineeringMaster of Science in Mechanical Engineering (MSME
RRT and Octomap based 3D environment exploration and mapping
No full textA Master of Science thesis in Mechatronics Engineering by Koshish Koirala entitled, “RRT and Octomap Based 3D Environment Exploration and Mapping”, submitted in May 2020. Thesis advisor is Dr. Shayok Mukhopadhyay. Soft copy is available (Thesis, Approval Signatures, Completion Certificate, and AUS Archives Consent Form).For autonomous navigation in an unknown environment, all robots need a map of the environment along with the robot's current location on the map. This work builds on existing rapidly-exploring random tree (RRT)-based exploration techniques and considers the mapping of three dimensional (3D) space using an Octomap. There have been previous efforts using multiple RRTs to produce map of 2D space. This work aims to utilize such efforts along with a 2D scanner mounted on a servo actuated tilting joint, to effectively generate a map of 3D space. The Gazebo simulator, present in the Robot Operating System (ROS), is used for simulations whereas the ROS Visualizer (RVIZ) is used for visualization. This work presents a 3D mapping strategy based on Octomaps and OctTrees whereas 2D Simultaneous Localization and Mapping (SLAM) running on ROS based Gmapping techniques provides robot localization information. A custom servo-based tilting platform has been designed and used for scanning 3D spaces with a traditional 2D laser scanner. The appropriate frame-transformations required to integrate such data onto the frame of a map being explored, are also shown. Further, the effects of running the proposed RRT based exploration algorithm with only a global detector, are compared explicitly with the case of using a local detector along with the global detector, and the improvements are summarized. Several experimental runs, and their results are presented to show the effectiveness of the proposed map exploration strategy.College of EngineeringMultidisciplinary ProgramsMaster of Science in Mechatronics Engineering (MSMTR
Improved-Performance Vehicle’s State Estimator Under Uncertain Model Dynamics
No full textA Master of Science thesis in Mechanical Engineering by Mohammad Avzayesh entitled, “Improved-Performance Vehicle’s State Estimator Under Uncertain Model Dynamics”, submitted in July 2020. Thesis advisors is Mamoun Abdel-Hafez and Mohammad Al-Shabi. Soft copy is available (Thesis, Approval Signatures, Completion Certificate, and AUS Archives Consent Form).This thesis demonstrates the improved-performance state estimation of the navigational system using few fusion techniques. In this study, the Smooth Variable Structure Filter (SVSF) and some of its recent forms are examined for state estimation applications under uncertainty in the model dynamics and varying environments. The developments of the SVSF in terms of robustness and optimality are investigated in this thesis. Moreover, its combinations with different filtering strategies to acquire better accuracy whilst being robust to model uncertainty are studied. State estimation techniques, such as Extended and Unscented Kalman filters (EKF & UKF), SVSF, the combination of SVSF with EKF (EK-SVSF) and the combination of UKF with SVSF (UK-SVSF), are applied on an experimental case study, which is the Partial Discharge Localization. Their performance and behavior are validated and compared. Based on the steady state results, we propose the use of UKF and SVSF in a hybrid filter, known as the UK-SVSF, as it has the combined advantage of both filters, fast convergence and low Mean Squared Error (MSE). The UK-SVSF is tested in a navigational system, where the MIDG unit and GPS antenna sensors are used with fusion techniques to combine data from the two sensors. The results are compared to the solution from the MIDG, EKF, SVSF, UKF and EK-SVSF. The results show that in the absence of added noise and model uncertainties, all the filtering strategies have almost identical performance. However, injecting uncertainties to the system causes the performance of the UKF and the EKF to degrade and to go out of bounds. On the other hand, adding noise to the system causes the path of the SVSF to become rough with oscillatory behavior around the truth path. Conclusively, the Root Mean Squared Error (RMSE) results reveal that in the presence of both: noise and modeling uncertainties, which is referred to as the worst-case scenario (large magnitude of noise and model uncertainty, and missing information), the UK-SVSF has the superior performance; it reduces the RMSE of SVSF and UKF by 20% and 33%, respectively. Moreover, its RMSE is less than the RMSEs that are obtained from EKF and EK-SVSF by 38% and 18%, respectively.College of EngineeringDepartment of Mechanical EngineeringMaster of Science in Mechanical Engineering (MSME
Nutrient Recovery from Wastewater Using Desalination Reject Brine
No full textA Master of Science thesis in Civil Engineering by Alaa Yasser Ahmed Fouad Kamel entitled, “Nutrient Recovery from Wastewater Using Desalination Reject Brine”, submitted in November 2020. Thesis advisor is Dr. Kazi Parvez Fattah. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).Reject brine, a waste by-product generated during the desalination process, is harmful when discharged into the environment, but it contains some useful minerals such as magnesium. Also, wastewater treatment plants utilizing centrifuge processing of sludge produce an effluent called centrate. This effluent is capable of causing operational problems, such as clogging of pipes and lowering biological treatment efficiency. Yet centrate is rich in nutrients such as phosphorus. This nutrient is the backbone of plant growth and is usually provided in the form of fertilizers. With diminishing availability of natural phosphorus, the cost of fertilizer production has seen rapid increase in recent years. Phosphorus recovery from centrate, with the help of an external magnesium source, can provide a sustainable alternative. Usually it is recovered in the form of struvite (magnesium ammonium phosphate) that can be used as a slow-release fertilizer. In this study, the feasibility of using the reject brine as a source of magnesium to produce struvite from centrate is studied in experiments using a bench scale jar test setup and a fluidized bed reactor. Factors affecting the precipitation of struvite, such as magnesium to phosphorus molar ratio, pH and the influence of other competing ions are investigated. Results show that around 90% of phosphorus removal can be achieved when operating at a Mg:P molar ratio of 3:1 and pH value of 9 when using both centrate or synthetic wastewater as a source of phosphorus and reject brine as a source of magnesium. Statistical analysis performed using Minitab shows that for most cases, the percentage phosphorus removal increases at higher pH and Mg:P molar ratios. The FTIR and XRD analysis shows that the precipitates formed contain primarily struvite. SEM-EDX analysis further validates presence of struvite as the precipitates have Mg:P molar ratios closer to the theoretical values of 1:1. Therefore, this study shows the potential of using reject brine as a magnesium source to efficiently recover phosphorus and produce high quality struvite.College of EngineeringDepartment of Civil EngineeringMaster of Science in Civil Engineering (MSCE