Faculty of Engineering & Applied Science

Permanent URI for this communityhttps://hdl.handle.net/10155/390

The Faculty of Engineering & Applied Science (FEAS) offers accredited undergraduate and graduate programs as well as completes research in engineering and applied science. Areas of focus include autonomous vehicle design, electric and hybrid vehicles, robotics and automation, cloud computing, electric and autonomous vehicles, clean energy, artificial intelligence, robotics, automation, and intelligent controls, thermo-fluids, and energy systems.

Browse

Now showing 1 - 20 of 660

A Graph Neural Network for pairwise surrogate modeling in population-based algorithms with tournament selection
(2024-04-01) Gharavian, Vida; Makrehchi, Masoud; Rahnamayan, Shahryar
Optimization problems widely arise in various science and engineering fields. Optimisation involves evaluating a candidate solution, which can be computationally intensive. Machine learning-based surrogate models can contribute to learning the specific pattern among the decision variables and objective values to reduce the computation time of fitness evaluation. In this study, we have proposed a novel pairwise surrogate model to identify the superiority between candidate solutions in a pairwise comparison. We demonstrated a Graph Neural Network (GNN) to be trained on number of pairs, then utilized to compare a pair of candidate solutions. To examine the efficacy of our model, we utilized the surrogate model on CEC2017 benchmarks in different dimensions. Moreover, the result of surrogate-assisted and none-assisted form of two well-known optimization algorithms were compared. Results show that the proposed method can significantly reduce the computing cost. In the presence of higher dimensions, our model is more effective than most surrogate models for comparison-based optimizers.
A hybrid approach for intersection management in V2X-enabled connected vehicles
(2024-08-01) Elmoghazy, Ammar; Elgazzar, Khalid; AlWidian, Sanaa
Autonomous Vehicles (AVs) have the potential to revolutionize transportation by enhancing safety, efficiency, and convenience. However, AVs face significant challenges in complex urban environments, particularly in accurately perceiving and navigating through intersections mainly due to occlusions. This thesis addresses these challenges by integrating Vehicle-to-Everything (V2X) communication with onboard sensors to improve AV perception and decision-making capabilities. In particular, this thesis proposes a hybrid centralized-decentralized management system, which maximizes the benefits of centralized control for strategic traffic management and the responsiveness of decentralized decision-making, using edge nodes as a traffic coordinators helps reduces the computational needs on the vehicle. Such a system leverages V2X data to enhance situational awareness, optimize traffic flow, and improve overall safety and efficiency in urban environments. The methodology involves using Simultaneous Localisation and Mapping - SLAM for mapping, particle filters for localization, and waypoint generation for planning and control. The hybrid system’s performance was evaluated through simulations and real-world experiments using scaled-down vehicles equipped with advanced sensing and communication technologies. Compared to purely centralized or decentralized approaches, the hybrid system achieved up to a 14% reduction in average travel times through intersections and a 20% improvement in overall traffic flow efficiency. This thesis contributes to the development of intelligent transportation systems by demonstrating the efficacy of hybrid intersection management in enhancing AV performance in urban environments.
A hybrid compensation-based misalignment tolerant wireless power transfer system for e-mobility
(2024-04-01) Shrestha, Niranjan; Williamson, Sheldon
The thesis focuses on developing a hybrid compensation with a phase shift control strategy, aiming for misalignment tolerant constant current/constant voltage (CC/CV) charging through a wireless power transfer (WPT) system for e-mobility. The thesis proposes a hybrid multi-resonant compensation network (LCC-LCC and LCC-S) for CC/CV charging during perfect alignment, controlled by the secondary side only. Additionally, the thesis introduces a phase shift control technique in the inverter to maintain the corresponding CC and CV charging mode during the misalignment up to 100 mm between primary and secondary coils. Initially, the theoretical analysis of the proposed system is described in detail. Then, simulation results for 3.7 kW and 270 W peak load were carried out in MATLAB Simulink. Lastly, experimental testing and validation were conducted for the proposed hybrid compensated system for 270 W peak load, applicable to the E-bike. The experimental results show good consistency with theoretical and simulation analysis.
A multistage-constant-current, temperature-controlled, health-conscious fast charging algorithm for lithium-ion batteries
(2024-08-01) Chetri, Chandan; Williamson, Sheldon
The economical operation and wider adaptability of an electric vehicle (EV) is highly governed by the energy storage system used in the vehicle. To enhance user convenience and compete with their gasoline counterparts, EVs need fast charging methods to achieve equivalent refueling times. However, fast charging can adversely affect the health and cycle life of the battery due to excessive temperature rise resulting in accelerated degradation of the battery chemistry. Especially in subzero conditions, the chemical reactions are much slower, resulting in increased internal impedance. This leads to a higher rate of temperature rise in battery temperature and eventually faster battery degradation. This thesis proposes a closed-loop Multistage-constant-current, Temperature-controlled (MCC-TC), Health-conscious Fast Charging strategy, which modulates the charging current considering the battery temperature as feedback. The experimental validation on an automotive grade battery cell depicts lower temperature rise and rate of temperature rise following the MCC-TC charging algorithm compared to the conventional Constant-Current Constant-Voltage (CC-CV) charging algorithm.
A novel approach for route generation and real-time scheduling for public services
(2024-04-01) Baghyari, Farhad; Seo, Jaho
Snowplowing and sweeping are essential services to municipalities, which affect travel safety, environment protection, and health to residents. To provide acceptable quality services, route optimization is one of the key strategies that allow for enhancing efficiency, saving costs, and balancing workloads among operational teams. In order to address this issue and reflect on recent research trends in routing problems that require variable conditions and real-time events, this study proposes two heuristic methods: Smart Selective Navigator and a two-stage algorithm for real-time scheduling and route generation. Through two major case studies — winter operations in the City of Oshawa and autonomous street sweeping in Uchi Park —the proposed methods demonstrate superior performance in generating optimal routes that satisfy complex constraints such as turn restrictions and supply limits and handle real-time events like vehicle breakdowns.
Access control obligation specification and enforcement using behavior pattern language
(2018-01-01) Sharghigoorabi, Mohammadhassan; Liscano, Ramiro
Increasing the use of Internet-based devices offers novel opportunities for users to access and share resources anywhere and anytime so that such a collaborative environment complicates the design of an accountable resource access control system. Relying on only predefined access control policies based on an entity's attributes, as in traditional access control solutions, cannot provide enough flexibility to apply continuous adjustments in order to adapt to any kind of operative run time conditions. The limited scope and precision of the existing policy-based access control solutions have put considerable limitations on adequately satisfying the challenging security aspects of the IT enterprises. In this research, we focus on the obligatory behavior that can play an important role in access control to protect resources and services of a typical system. Since traditional access control is performed only once before the resource is accessed by the subject, the access control system is unable to control the fulfillment of obligation while the access is in progress. Practically, such a requirement is implemented in hard-coded and proprietary ways. Consequently, the lack of sophisticated means for specification and enforcement of obligation in access control system decreases its flexibility and may also lead to the security breach in sensitive environments. We provide a descriptive language that is capable of defining a variety of complex behavior patterns based on a sequence of user actions. Such a description can be used to specify different elements of the obligation in order to attach to a policy language, and it is also used to generate queries for behavior matching purposes. Moreover, we propose a behavior pattern matching framework to approve the fulfillment of the obligation by looking into the audit logs. However, this method is extremely inadequate for ongoing obligations. Therefore, we proposed a compliance engine by utilizing complex event processing in order to make a decision to revoke or continue the access in a timely manner. We implemented both frameworks that can be used to approve the obligation fulfillment as well as to evaluate the expressive power and complexity of our proposed language.
Achieving high efficiency thermoelectric heating and cooling with metal foam heat exchangers
(2014-04-01) Clark, Gavin; Rohrauer, Greg
This thesis examines the development of a high efficiency heat pump system using thermoelectric (TE) and reticulated metal foam (RMF) technologies to power a vehicle`s battery thermal management system. The focus is split into two areas: first a review of TE’s sourcing or removing heat, second an examination of compact heat exchanger (HX) design. Five TE suppliers were investigated to understand the performance and limitations of their TE modules. Testing showed the Kyrotherm product to be superior so it was used as a design basis. RMF’s are known to be an effective means to improve the performance of compact heat exchangers, thus HX’s were evaluated with RMF foams compressed to varying densities in order to understand their potential in conjunction with thermoelectric devices. Experimental results showed performance was limited due to adequate bonding, yet still on par with the highest efficiency technologies currently on the market.
Active balancing of lithium-ion cells for maximum power discharging
(2018-07-01) Capano, David; Williamson, Sheldon
The future of Electric Vehicle’s (EV) depends on the adoption of the technology. Currently the limiting factor for EV adoption is mainly the initial cost, the driving range, charging capability, and the battery life. The Battery Management System (BMS) in any Lithium chemistry battery system is used to keep the cells in the optimal operating conditions. The BMS in standard EV batteries employ series cell balancing only while charging. The discharge balancing technique can be used to increase useable capacity from an EV battery because at the end of a cycle the stronger cells have some remaining capacity which can used to assist the weaker cells. This work explores the difference in useable capacity with active cell balancing vs. passive balancing for both new and aged cells near End of Life (EOL). In this work the proposed discharge balancing technique has been researched, simulated, and implemented in hardware testing.
Active transport and concentration of analytes in microfluidic paper based analytical devices using ion concentration polarization
(2019-04-01) Crowley, Michael; MacDonald, Brendan
Microfluidic paper-based analytical devices (µPADs) have a high potential for miniaturizing complex testing functions, since they are inexpensive, disposable, and portable. Paper has the advantage over traditional fluid channel systems in that it houses capillary-driven flow, which requires no external pumps or equipment. However, these paper-based devices have one disadvantage in that they do not enable further flow of fluids after becoming fully wet. In this work, active transport and concentration of analytes in fully wet paper-based assays is demonstrated by leveraging ion concentration polarization (ICP). The efficacy of ICP-inducing µPADs is demonstrated through transporting and concentrating dye, fluorescein and immunoglobulins. The application of actively concentrating immunoglobulins - antibodies with sample concentrations that are typically below traditional limits of detection - is a novel application of ICP and can be used to create universally accessible allergy tests.
Adaptive IEEE 802.15.4e LLDN scheduler for wireless network control systems
(2015-12-01) Karimpoor, Kiana; Liscano, Ramiro
An active area of research in the automotive research community is the stability of Long Commercial Vehicles (LCVs) using active trailer steering and/or braking. These LCVs rely on sensor data located across different regions of the tractor and trailers and compose the LCV. Communication of the sensor data to the Electronic Control Unit (ECU) of the active trailer system is performed through a conventional wired bus. The benefits of wireless communication for an LCV are improved flexibility, maintenance, elimination of physical socket connections and, reduction of weight related to the wires in the vehicle. In LCVs there is a natural demarcation point between the tractor and trailers where wireless communications can replace the wired communication bus. This thesis investigates the latency and throughput of wireless communication using IEEE 802.15.4 and IEEE 802.15.4e Low Latency Deterministic Network (LLDN) protocols for different sensor sampling rates in an LCV scenario and creates a guidelines for the system designers to select the right sensor sampling times. Furthermore, it proposes a new adaptive IEEE 802.15.4e LLDN algorithm that computes the optimal timeslot and superframe duration based on the sensor node data inter-arrival times to achieve the desired LCV controller latency that will exhibit stable behaviour. Simulation results confirm that this adaptive IEEE 802.15.4e LLDN algorithm can configure the IEEE 802.15.4e LLDN that present the best results for delay as well maximum throughput for a desired latency.
Additive manufactured biodegradable and biocompatible polymeric nanocomposite scaffolds for bone tissue engineering applications
(2021-08-01) Karimipour Fard, Pedram; Rizvi, Ghaus; Pop-Iliev, Remon
In this thesis, the focus is on using the fused deposition modeling (FDM) method to manufacture functional biodegradable nanocomposite Polymeric Bone Tissue Scaffolds (PBTS). PBTSs are complex products, which have attracted significant attention in the literature in recent decades. In this study, a commercial and user-friendly FDM manufacturing technique was used to fabricate Polycaprolactone (PCL)/Nano-Hydroxyapatite (nHA)/Chitin-Nano-Whisker (CNW) nanocomposite scaffolds with advanced geometrical designs. The fabricated scaffolds were developed to have functional mechanical, biological, and biodegradation properties. Multiple stages of experimental, numerical, and analytical analyses were performed to achieve these goals. The scaffolds were manufactured in Triply Periodic Minimal Surfaces (TPMS) designs. The impacts of the advanced biomimetic designs, porosity, and biodegradation on the mechanical and morphological properties of the scaffolds were investigated. The nanocomposite filaments for the FDM method were produced using green manufacturing methods. The manufactured novel FDM filaments were characterized using Thermo-Gravimetric Analysis (TGA) and Fourier Transform Infrared Spectroscopy (FTIR) to ensure the precision of the nanocomposite contents. The FDM processing conditions of the novel nanocomposite filaments were optimized using Taguchi’s orthogonal array experimental design method to achieve the optimal mechanical properties and structural integrity. The 3D printed nanocomposite bone tissue scaffolds were characterized to assess their mechanical and biological properties. The biodegradation rates of the 3D printed Gyroid-designed nanocomposite PBTSs were estimated in sixty weeks of biodegradation, employing numerical, and experimental results. Machine learning methods were used to connect the independent experimental and numerical results and extract objective functions to model properties of the 3D printed nanocomposite PBTSs. Multi-objective optimization was performed to propose non-dominated optimal options for the PBTSs porosity and the nanocomposite fillers percentages. The results indicated that the proposed green manufacturing method successfully fabricated the nanocomposite FDM filaments with high precision. The FDM printed PCL/nHA/CNW nanocomposite PBTSs with Gyroid structure have high mechanical properties in the practical range of bone tissue scaffolds, enhance cell proliferation and attachment to the scaffolds and biodegrade in the practical period for PBTSs. The multi-objective optimization method presents a few significant non-dominated optimal options, which can be selected based on the consumer’s priorities.
Addressing electrode-specific degradation in the production and performance of electrochemical energy storage systems
(2023-08-01) Khosravinia, Kavian; Kiani, AmirKianoosh; Lin, Xianke
This thesis addresses the pressing issue of sustainable development and climate change by examining the life cycle (degradation) of electrochemical energy storage devices. Specifically, it investigates a green synthesis technique for high-performance pseudocapacitor electrodes and uses machine learning algorithms to predict and prevent degradation mechanisms in lithium-ion batteries. The research demonstrates the effectiveness of the laser irradiation technique, called ultra-short laser pulses for in situ nanostructure generation (ULPING) for fabricating a metal oxide layer on a titanium sheet under ambient conditions, as well as the potential of machine learning algorithms as a tool for constructing mathematical models to forecast the electrochemical behavior of pseudocapacitors. The thesis also highlights the importance of utilizing data-driven approaches in electrode design procedures and promoting sustainable habits in all aspects of life. In addition, the study provides insight into the modeling and prediction of the electrochemical behavior performance of pseudocapacitors, which could facilitate the development of optimal electrodes. Moreover, the research examines one of the most detrimental degradation mechanisms that occur during the fast-charging process, known as the deposition of metallic lithium or lithium plating, in lithium-ion batteries. The proposed machine learning approach based on ensemble selection accurately predicts the anode potential under various charging conditions and achieves high accuracy in preventing lithium plating. Overall, this research offers promising methods for employing ultra-short laser pulses for in situ nanostructure generation to fabricate nanostructures on transition metals that have the potential to be used in pseudocapacitor electrodes and highlights the importance of utilizing machine learning techniques in predicting and preventing degradation mechanisms in electrochemical energy storage devices.
An advanced electrospinning method of fabricating nanofibrous patterned architectures with controlled deposition and desired alignment
(2015-11-18) Rasel, Sheikh Md; Rizvi, Ghaus
We introduce a versatile advanced method of electrospinning for fabricating various kinds of nanofibrous patterns along with desired alignment, controlled amount of deposition and locally variable density into the architectures. In this method, we employed multiple electrodes whose potentials have been altered in milliseconds with the help of microprocessor based control system. Therefore, key success of this method was that the electrical field as well as charge carrying fibers could be switched shortly from one electrode’s location to another, as a result, electrospun fibers could be deposited on the designated areas with desired alignment. A wide range of nanofibrous patterned architectures were constructed using proper arrangement of multiple electrodes. By controlling the concurrent activation time of two adjacent electrodes, we demonstrated that amount of fibers going into the pattern can be adjusted and desired alignment in electrospun fibers can be obtained. We also revealed that the deposition density of electrospun fibers in different areas of patterned architectures can be varied. We showed that by controlling the deposition time between two adjacent electrodes, a number of functionally graded patterns can be generated with uniaxial alignment. We also demonstrated that this handy method was capable of producing random, aligned, and multidirectional nanofibrous mats by engaging a number of electrodes and switching them in desired patterns. A comprehensive study using finite element method was carried out to understand the effects of electrical field. Simulation results revealed that electrical field strength alters shortly based on electrode control switch patterns. Nanofibrous polyvinyl alcohol (PVA) scaffolds and its composite reinforced with wollastonite and wood flour were fabricated using rotating drum electrospinning technique. Morphological, mechanical, and thermal, properties were characterized on PVA/wollastonite and PVA/wood flour nanocomposites containing 0, 5, 10, and 20 wt % of fillers. Morphological analyses carried out by digital optical microscope, scanning electron microscopy, x-ray computed tomography, and Fourier transform infrared spectroscopy, confirmed the presence and well dispersion of fillers in the composites. In addition, improvement of mechanical properties with increased filler content further emphasized the adhesion between matrix and reinforcement. PVA with 20 wt % wollastonite composite exhibited the highest tensile strength (11.99 MPa) and tensile module (198 MPa) as compared to pure PVA (3.92 MPa and 83 MPa, respectively). Moreover, the thermal tests demonstrated that there is no major deviation in the thermal stability due to the addition of wollastonite in PVA scaffolds. Almost similar trend was observed in PVA/wood flour nanocomposites where tensile strength improved by 228 % for 20 wt % of reinforcement. The PVA/wollastonite and PVA/wood flour fibrous nanocomposite which poses higher mechanical properties might be potentially suitable for many advanced applications such as filtration, tissue engineering, and food processing. We believe, this study will contribute to further scientific understanding of the patterning mechanism of electrospun nanofibers and to allow for variety of design of specific patterned nanofibrous architectures with desired functional properties. Therefore, this improved scheme of electrospinning can have significant impact in a broad range of applications including tissue engineering scaffolds, filtrations, and nanoelectronics.
Advances in parallel robotics for flexible and reconfigurable manufacturing
(2014-04-01) Coppola, Gianmarc; Zhang, Dan; Liu, Kefu
Parallel robotic manipulators are a specific type of robot that has multiple limbs which are ultimately connected to a moving body. Within this regime, there are several sub-classes of robots characterized by certain inherent traits. Common to all sub-classes is the ability to articulate the moving platform by actuating each of the limbs. In general, it has been shown that these types of robotic manipulators possess several types of advantageous properties. Some of these properties are: good dynamic character, high stiffness, high precision, large payload to weight ratio, and high speed. Flexible and reconfigurable manufacturing regimes are new manufacturing system paradigms that aim at achieving cost-effective and rapid system changes. Essentially, a system classified as flexible or reconfigurable would be one that is adaptive to change in the market without the need to re-design or re-develop its components. The advantage of such a system is in theory very large. To date, there has been some enhancements made in the area, however there are still many open aims and possible improvements to be investigated. Much of which aims at furthering the concepts from theory to practical applications. The main objective of this dissertation is to enhance the knowledge base in flexible and reconfigurable systems through parallel robotics. Specifically, by utilizing new ideas in parallel robotics tailored to these manufacturing regimes, significant improvements in the knowledge base are attained. These can be classified under one specific regime of parallel robotics and further categorized as passive, semi-active, and active (adaptive). This thesis first focuses on a new design methodology related to flexible and reconfigurable manufacturing. Essentially, the method proposes a systematic approach to recon figure the dynamic properties of robotic devices for various functional requirements that would be part of a flexible manufacturing situation. The method is tested on an example structure and results indicate that the proposed reconfiguration method outperforms existing devices. Next, this dissertation focuses on the design of new robotic architectures that are more adaptive. Specifically, the goal is to achieve structures that can be adaptive in real-time. Existing structures are only reconfigurable passively and need to stop operation in order to reconfigure manually. To this end, a hybrid structure that is semi-active reconfigurable is first investigated. It is dubbed the ReSl-Bot. A complete engineering analysis and design is conducted illustrating its properties. To take this one step further, a novel class of hybrid adaptive parallel robots is then proposed. A 6-DOF robot belonging to this class called the HAPM mk.1 is studied in detail. It is effectively shown that this novel design has the ability to adapt properties actively. This type of adaption could be used for the performance enhancement in many applications, particularly for flexible manufacturing. Properties such as DOF, stiffness, dexterity, precision, kinetics, energy consumption, backlash, etc. could potentially be altered for varying applications and requirements. Notably, a complete theoretical analysis is conducted, ending with analytical dynamics and control.
Advancing the technology development for better quality wood plastic composites: process ability study
(2009-03-01) Semeralul, Hamid Osman; Rizvi, Ghaus
Wood Plastic Composites (WPC) have advantages over natural wood such as improved stiffness, recyclability, and waste minimization. However, issues such as the difficulty of processing WPC with conventional methods, volatile emission from the wood and the composites’ lack of strength must be addressed. A system for continuous extrusion of rectangular profiles of WPC was developed and some critical processing strategies were identified. The use of a lubricant and a calibrator also improved the profile extrusion of WPC. In this work, glass was also added to improve WPC’s mechanical strength. Generally, a glass content of 2.5% appears to improve the properties but further addition does not have a significant effect. Foaming of WPC, which can enhance their properties, was investigated through studying the effect of heating time and temperature on void fraction and cell density.
The aeroacoustics response and shear layer dynamics of confined cavities subject to low Mach number turbulent flow
(2023-04-01) Hanna, Marc; Mohany, Atef
Cavities exposed to low Mach number flow in various engineering applications are often liable for generating flow-excited acoustic oscillations, resulting in large acoustic amplitudes and vibrations. This compromises the safety and reliability of critical equipment due to a phenomenon attributed to interaction between the instability of the shear layer and the acoustic modes of a given system. This thesis experimentally investigates the aeroacoustics response of cylindrical cavities having aspect ratios of h/L = 0.5, 1, and 1.5, where h is the cavity depth and L is the shear layer impingement length, up to flow velocities of Mach 0.4. In view of the cavity confinement, the effects of the admission ratio w/W, where w is the cavity width and W is the duct width, on the aeroacoustics response and shear layer dynamics are also considered. The work extends the investigation to two-dimensional rectangular cavities and square cavities with similar aspect and admission ratios to the cylindrical cavities, as to establish the effect of the cavity shape on the resonance excitation frequencies and hydrodynamic modes of the system. Acoustic pressure measurements present Strouhal periodicities that agree well with values reported in literature. Cylindrical and square cavities with aspect ratio h/L = 0.5, however, exhibit unique behaviour due to the interference of the recirculation region within the cavity, ultimately modifying the symmetry of the shear layer. Particle image velocimetry (PIV) measurements present spatial characteristics of the shear layer dynamics, revealing improved flow modulation with increasing acoustic pressure, and significant asymmetry for shallow aspect ratios. The work presented in this thesis provides novel insight of the shear layer instability in confined cavities, and its effect on the flow-sound interaction mechanism.
An AFE based embedded system for physiological computing
(2019-11-01) Khan, Md. Nazrul Islam; Eklund, Mikael
The present hospital-based health care system will be burdened because of the growing aging population. Aging and stress result in cardiovascular diseases that cost around seventeen million lives globally every year. To control cardiovascular ailments, at-home monitoring of blood pressure is very important which helps diet control and promote medication adherence. The present health monitors are by default bulky, daunting, invasive, and not suitable for home use. The de-facto architecture of such systems entails discrete sensors and analog sub-systems known as the analog front end (AFE) for biosignal acquisition, conditioning, and vital bridging function. Being discrete and analog, signal processing is limited. Besides, with large form factor, component counts and power consumption increase with the constant need for calibration. For more than one century, the non‐invasive measurement of blood pressure has relied on the inflation of pneumatic cuffs around a limb. In addition to being occlusive and thus cumbersome, clinical cuff‐based methods, provide intermittent BP readings, hence impeding the suitable monitoring of short‐term BP regulation mechanisms. Cuff‐based methods may not be a true representative of BP. Therefore, the development of novel technologies that eliminate the use of pneumatic cuffs is justified. In this thesis, I present a highly integrated programmable AFE based biosignal computing platform, named TasDiag. TasDiag is a novel, integrated, remote platform capable of multimodal biosignal computing including non-invasive, continuous, and cuff-less BP estimation based on pulse transit time. Being integrated, and digital, TasDiag is a single board solution with an auto calibration scheme implemented through novel signal processing and computing. The developed system is validated using real-time data from human subjects and subjected to various statistical analyses for performance and accuracy. Test results show TasDiag comply with the Association for Advancement for Medical Instrumentation standard and can replace its industry-standard counterparts.
An investigation of ultraviolet and ionizing radiation on the eye-lens of rainbow trout
(2024-06-01) Kocemba, Marta; Waller, Edward; Waker, Anthony
The lens of the eye is one of the most radiosensitive tissues in the body, and the effects of radiation on the eye-lens are not fully understood. Dose limit and tissue effect threshold recommendations have been lowered due to cataracts occurring at unexpected doses, and there is therefore a need for biological experiments on the early stages of cataractogenesis. There is also a need for radiobiological evidence in the context of environmental radioprotection, since the current recommendations for dose limits to non-human biota are based on assumptions rather than evidence of radiation response. In this work, the effects of ionizing and ultraviolet radiation on the eye-lens of rainbow trout have been investigated in vitro. Eye-lenses were excised and maintained in culture, then irradiated with either X-rays or ultraviolet (UV) radiation and assessed for several types of damage response. Optical quality was quantified using laser focal analysis; the structural integrity of cell membranes was assessed by measuring protein leakage from eye-lenses; and the response of lens cells to the radiation was characterized using proteomics analysis. A dose of 0.2 J/cm² of UVB radiation was shown to produce no changes in the optical quality of intact rainbow trout eye-lenses over 30 days post-irradiation. However, there is evidence of a damage-response process that triggers cellular 'housekeeping' and results in irradiated lenses maintaining transparency longer than control lenses. Comparative studies with groups of lenses being exposed to either 1 J/cm² of UVB radiation or 2 Gy of X-rays has shown that this dose of ionizing radiation produces significant changes in the expression of proteins related to cell membranes, DNA repair, and removal of damaged proteins. The UVB dose led to elevated expression of the same types of proteins, but not in significant amounts. Combining results across damage assays and experiments has revealed trends which support the concepts of individual variation in radiosensitivity, membrane damage and bystander effect as factors in early cataractogenesis, and the relationship between stress response and lens transparency. Overall, this characterization of specific aspects of damage response in the eye-lens to ionizing and ultraviolet radiation has contributed to the understanding of cataractogenesis as well as environmental radioprotection.
Analysis and assessment of integrated waste-to-energy systems based on plastic wastes for multigeneration
(2022-04-01) Ismail, Mohamed; Dincer, Ibrahim
This thesis proposes three wastes to energy multigeneration systems that are based on plastic wastes. The three systems are coupled with renewable energy resources like solar energy, geothermal energy, and wind turbine energy. The three systems are designed to convert plastic waste into five useful outputs of electric power, heating, fresh water, domestic hot water, and hydrogen. The proposed locations for the three systems are Cordoba, Spain for the first multigeneration system, Kakkonda, Japan for the second multigeneration system and Tarfaya, Morocco for the third system. The systems are analyzed thermodynamically and studied parametrically to identify optimum operating conditions. Energy and exergy analyses are performed to identify the efficiency of each system. According to the findings, the first system has the highest overall energy efficiency at 71.43%, while the second system has the highest exergy destruction rate 8,141.58 kW at the gasifier.
Analysis and design of computationally efficient modulation schemes for Three Phase Three Switch rectifier for transportation electrification
(2018-02-01) Channegowda, Janamejaya; Williamson, Sheldon
It is a well-known fact that the transportation sector emits a large amount of pollutants to the atmosphere. The growing need for reducing the carbon footprint has led to sincere efforts being made in the direction of electrification of commercial vehicles, which conventionally run on by-products of crude oil. The Canadian government is currently aiming at reducing greenhouse emissions by 30% below the early 2000s levels by the year 2030. This goal has led to major auto manufacturers releasing their respective models of battery-powered electric vehicles (EVs) completely compliant with the SAE J1772 standards. However, the commercial success of EVs heavily relies on the presence of high-efficiency charging stations. This thesis reviews presently available, Level 3/DC fast charging systems, followed by a brief description and evaluation of DC fast-charging infrastructure. Different power converter topologies and viable configurations are presented, compared, and evaluated, based on the power level requirements, efficiency of the topology, cost, and technical specifications. In this thesis the possibility of employing the Three Phase Three Switch (TPTS) converter as a single-stage charger for DC fast charging of electric vehicles is explored. Control of contemporary three phase power converters, employed in charging infrastructures, is achieved by Space Vector (SV) based modulation schemes. This thesis proposes a novel modulation technique for TPTS rectifier. The general SV modulation scheme xxvii xxviii used to control the TPTS is reviewed in this thesis. Numerous switching combinations possible for different positions of the Zero and Active vectors are derived. Based on the positions of these vectors in different sectors of the SV diagram, several switching sequences are presented. The switching combinations are analyzed to obtain three modulating waves. The new carrier-based modulation scheme for TPTS is implemented and validated using software simulation. This new scheme is easier to implement compared to the traditional SV based modulation technique due to reduced number of mathematical computations. A 1 kW hardware prototype was built to validate the proposed modulation scheme. This thesis provides a detailed description about arriving at the proposed modulation scheme for TPTS from traditional SV modulation scheme. The implementation of the converter and its performance analysis is reported in this thesis

Browse

Browsing Faculty of Engineering & Applied Science by Title