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Sustainable Cooling and Lubrication Strategies in Machining Processes: A Comparative Study
No full textApplying an adequate cooling and lubrication technique during machining processes is an important issue which affects the machining system efficiency. Flood cooling offers an effective solution to reduce the effect of the high heat generated during cutting processes; however, it is not a sustainable strategy because of the health and environmental concerns associated with its utilization. Therefore, several cooling and lubrication strategies have been suggested and used as alternatives to the flood cooling. These strategies include; dry cutting, cryogenic approach, minimum quantity lubrication (MQL), nano-cutting fluids, and MQL-nano-fluids. In this work, a comparative study is presented to evaluate the sustainability effectiveness of these strategies. In order to evaluate the strategies effectiveness, five sustainability indicators are used; namely, energy consumption, personal safety and health, waste management, machining costs, and environmental impact. A weighted decision matrix is developed to assess the studied strategies in terms of the employed sustainable indicators
The Optimization of Modified Composite Nano-materials as a Novel Approach to Dental Hygiene Remediation
No full textA Master of Science thesis in Chemical Engineering by Marah Mazen Mahmoud entitled, “The Optimization of Modified Composite Nano-materials as a Novel Approach to Dental Hygiene Remediation”, submitted in December 2019. Thesis advisor is Dr. Taleb Ibrahim and thesis co-advisor is Dr. Sarah Dalibalta. Soft copy is available (Thesis, Approval Signatures, Completion Certificate, and AUS Archives Consent Form).Oral diseases have always been a challenge to contend with in the modern world, especially with the adoption of unhealthy lifestyles. These habits have contributed to the growth of S. mutans, P. gingivalis, and H. pylori, among other oral bacteria that encourage the development of dental caries, periodontal diseases, and cancer. To battle these diseases, conventional methods such as toothpastes and mouthwashes have been used and unconventional methods such as carbon compounds and nanoparticles have been developed. The complexation of cationic surfactants and smectite clays has been explored and an example of such an organoclay is the one made of cetylpyridinium chloride (CPC) and montmorillonite (Mt). In this study, the aforementioned organoclay was prepared and optimized with respect to CPC uptake by varying the contact time between 1 hour and 3 days, varying the CPC concentration between 5.11 × 10&'M and 4.52 × 10&*M, and varying the temperature between 25°C and 55°C. The experiments showed that shaking the complex was a better approach to intercalation than using the magnetic stirring plate, and that a 24-hour contact period at a moderate concentration of 1.44 × 10&*M at 25°C provided the highest level of intercalation and relatively low levels of desorption. Additionally, UV radiation had no effect on the intercalation extent of CPC with montmorillonite. The prepared solids were then tested on saliva samples plated in nutrient agar. These experiments showed that the prepared complex retained its antibacterial behavior through a likely combination of adsorption and lysis.College of EngineeringDepartment of Chemical EngineeringMaster of Science in Chemical Engineering (MSChE
Doxorubicin-encapsulated Albumin liposomes with acoustic triggering for cancer treatment
No full textA Master of Science thesis in Biomedical Engineering by Afifa Farooq entitled, “Doxorubicin-encapsulated Albumin liposomes with acoustic triggering for cancer treatment”, submitted in May 2019. Thesis advisor is Dr. Ghaleb Husseini. Soft and hard copy available.With cancer being the leading cause of death worldwide, increasing economic and social resources are being directed by researchers and healthcare professionals to treat the disease, or at least provide palliative care to patients that cannot be treated due to advanced cancerous growth. While the end goal of all the cancer-related research is its cure, current technology is focused on the creation of smart drug delivery systems (DDS) that aims to diagnose and treat cancer. For effective design of these systems, chemotherapeutic agents are combined with carriers, which evade the immune response, to achieve desired drug release amounts and rates through ligand-targeting and external release stimuli. This work provides a literature review that aims to lay the groundwork for development of the following DDS: Albumin-bound stealth liposomes encapsulated in the chemotherapeutic drug, doxorubicin, with ultrasound-triggered drug release for the treatment of breast and pancreatic cancer. Experimental work was carried out involving the synthesis and characterization of the liposomes, along with nine model fitting exercises to determine the best fits for experimental data. Large unilamellar vesicles for control and albumin-bound liposomes, with sizes of 86.01 ± 2.97 nm and 86.17 ± 2.956 nm, respectively, were synthesized. Drug release by 20 kHz pulsed ultrasound release was carried out at low intensities with maximum releases of 90.25% at 20% intensity, 95% at 25% intensity, and 99.7% at 30% intensity for control liposomes, followed by 78.53%, 88.41%, 96.27% at the respective intensities for albumin-liposomes obtained over a period of 3 minutes. Albumin-liposomes were found to be more stable with doxorubicin encapsulation as opposed to calcein encapsulation. In addition, model fitting revealed the Korsmeyer-Peppas and Higuchi models as the best fits for doxorubicin-liposomes; while the Korsmeyer-Peppas and Weibull models were found to better predict calcein-liposome drug release behavior. Analysis of the release exponents, from Korsmeyer-Peppas linear regression, showed that both doxorubicin and calcein liposomes exhibited anomalous drug release kinetics.College of EngineeringMultidisciplinary ProgramsMaster of Science in Biomedical Engineering (MSBME
TCAD Simulation and Analysis of Selective Buried Oxide MOSFET Dynamic Power
No full textLow power consumption has become one of the major requirements for most microelectronic devices and systems. Increasing power dissipation may lead to decreasing system effciency and lifetime. The BULK metal oxide semiconductor field-effect transistor (MOSFET) has relatively high power dissipation and low frequency response due to its internal capacitances. Although the silicon-on-insulator (SOI) MOSFET was introduced to resolve these limitations, other challenges were introduced including the kink effect in the current-voltage characteristics. The selective buried oxide (SELBOX) MOSFET was then suggested to resolve the problem of the kink effect. The authors have previously investigated and reported the characteristics of the SELBOX structure in terms of kink effect, frequency, thermal and static power characteristics. In this paper, we continue our investigation by presenting the dynamic power characteristics of the SELBOX structure and compare that with the BULK and SOI structures. The simulated fabrication of the three devices was conducted using Silvaco TCAD tools in 90 nm complementary metal oxide semiconductor (CMOS) technology. Simulation results show that the average dynamic power dissipation of the CMOS BULK, SOI and SELBOX are compatible at high frequencies with approximately 54.5 μW. At low frequencies, the SOI and SELBOX showed comparable dynamic power dissipation but with lower values than the BULK structure. The difference in power dissipation between the SELBOX and BULK is in the order of nano watts. This power difference becomes significant at the chip level. For instance, at 1 MHz, SOI and SELBOX exhibit an average dynamic power consumption of 0.0026 μWless than that of the BULK structure. This value cannot be ignored when a chip operates using thousands or millions of SOI or SELBOX MOSFETs
Proton-Exchange Membrane Fuel Cell Stack Model Parameters Estimation and Model Validation
No full textA Master of Science thesis in Electrical Engineering by Aya Mohamad Taieb entitled, “Proton-Exchange Membrane Fuel Cell Stack Model Parameters Estimation and Model Validation”, submitted in April 2019. Thesis advisor is Dr. Shayok Mukhopadhyay and thesis co-advisor is Dr. Amani Al-Othman. Soft and hard copy available.A proton-exchange membrane fuel cell (PEMFC) is a promising, clean, and efficient power device that converts the chemical energy stored in a fuel into electricity directly. Hydrogen is supplied from an external tank and it is oxidized at the anode of the fuel cell, this activity releases electrons, which are made to flow through an external circuit. Oxygen is supplied at the cathode where it is reduced by the electrons flowing in the external circuit. The growing popularity of using PEMFC stacks in stationary, portable, and transportation applications is driving researchers to develop dynamic models to accurately capture the electrical characteristics and runtime performance. These characteristics are critical when integrating a fuel cell stack with power conditioning units (PCUs), and power electronics onboard fuel cell powered systems. Conventional PEMFC models may be complex and substantial effort is required to estimate parameters of such models. This work establishes a simple equivalent electrical circuit model of a PEMFC stack that captures the voltage-current (V-I) runtime characteristics under different load, and under different hydrogen flow rate conditions. It proposes a well-known equivalent circuit model of a battery, to be modified and used, as a model for a PEMFC stack. The existing adaptive parameters estimation (APE) technique is used to estimate the proposed PEMFC stack’s model parameters. Also, the concept of the state of charge (SoC) of a battery is thought as analogous to the amount of hydrogen available in a PEMFC stack’s supply tank. In this work, an existing battery model is modified to model the electrical performance of a 200-W PEMFC stack. All the model parameters are estimated using the APE technique that is known to require few experiments. The model is validated experimentally under different load conditions for the 200-W PEMFC stack. In addition, the model is validated with a different fuel cell stack of a smaller size, i.e. a 30-W PEMFC stack. All results show reasonably accurate terminal voltage estimation with error in the order of millivolts, and 95.84% of the all samples of estimated terminal voltage have between ± 0.1% error compared to the actual terminal voltage.College of EngineeringDepartment of Electrical EngineeringMaster of Science in Electrical Engineering (MSEE
Vigilance Decrement and Enhancement Techniques: A Review
No full textThis paper presents the first comprehensive review on vigilance enhancement using both conventional and unconventional means, and further discusses the resulting contradictory findings. It highlights the key differences observed between the research findings and argues that variations of the experimental protocol could be a significant contributing factor towards such contradictory results. Furthermore, the paper reveals the effectiveness of unconventional means of enhancement in significant reduction of vigilance decrement compared to conventional means. Meanwhile, a discussion on the challenges of enhancement techniques is presented, with several suggested recommendations and alternative strategies to maintain an adequate level of vigilance for the task at hand. Additionally, this review provides evidence in support of the use of unconventional means of enhancement on vigilance studies, regardless of their practical challenges
Automation in Construction Project Execution – A Theoretical Framework
No full textA Master of Science thesis in Engineering Systems Management by Yousef Awni Alsheikh entitled, “Automation in Construction Project Execution – A Theoretical Framework”, submitted in July 2019. Thesis advisor is Dr. Salwa Beheiry. Soft and hard copy available.Technology utilization and digitization is the new trend in the construction industry. It ensures a smooth flow of information and exchange of data among different stakeholders in construction projects. Construction automation can be defined as a self-regulating process where the use of self-governing mechanical and electrical devices in addition to computer software, programs and data-acquiring technologies in order to carry out jobsite activities and operations automatically or with minimal human intervention [1]. The aim of this thesis is to develop an Automation in Construction Index (AICI) to measure the level of adoption of automation in construction project execution, in terms of the cost and time of the project. Furthermore, factors from the literature were highlighted to best represent AICI which are Internet of Things, Building Information Modelling, Robotics and 3D Printing. To validate the factors that were drawn from the literature, a panel of eleven construction industry professionals and ten academics was consulted. The Relative Importance Index (RII) methodology was used out as a quantitative approach to rank the importance of applications/technologies to the automation process in terms of time and cost. All factors obtained from the literature were deemed important by the panel, in varying degrees. The results ranged from RII values equal to 0.819 and 0.848 in terms of cost and time respectively for the integration of Building Information Modelling and Augmented Reality to RII values equal to 0.495 and 0.571 in terms of cost and time for the 3D printing. In addition, results from RII were used to assign weights for each application in terms of cost and time in order to develop the AICI. These weights are essential as they indicate the level of contribution of each factor/application to the overall project’s automation level. Hence, anticipating the cost and time deviation of the construction projects.College of EngineeringDepartment of Industrial EngineeringMaster of Science in Engineering Systems Management (MSESM
Multiple Proposals for Continuous Arabic Sign Language Recognition
No full textThe deaf community relies on sign language as the primary means of communication. For the millions of people around the world who suffer from hearing loss, interaction with hearing people is quite difficult. The main objective of Sign language recognition (SLR) is the development of automatic SLR systems to facilitate communication with the deaf community. Arabic SLR (ArSLR) specifically did not receive much attention until recent years. This work presents a comprehensive comparison between two different recognition techniques for continuous ArSLR, namely a Modified k-Nearest Neighbor (MKNN) which is suitable for sequential data and Hidden Markov Models (HMMs) techniques based on two different toolkits. Additionally, in this work, two new ArSL datasets composed of 40 Arabic sentences are collected using Polhemus G4 motion tracker and a camera. An existing glove-based dataset is employed in this work as well. The three datasets are made publicly available to the research community. The advantages and disadvantages of each data acquisition approach and classification technique are discussed in this paper. In the experimental results section, it is shown that classification accuracy for sign sentences acquired using a motion tracker are very similar the classification accuracy for sentences acquired using sensor gloves. The modified KNN solution is inferior to HMMs in terms of the computational time required for classification
Analysis of macro and micro elemental composition of different extracts and finished products of the medicinal Herb – Terminalia bellirica
No full textTerminalina bellirica is considered to be a sacred plant with five distinctive tastes (sweet, sour, salty, bitter, and pungent). It stimulates the proper functioning of the digestive system, sensory organs and it is very effective in treating several medical conditions. Four types of extracts were prepared (aqueous extracts of T. bellirica fruit, alcoholic extract of T. bellirica fruit, alcoholic extract of seed oil from T. bellirica nuts, and alcoholic extract of T. bellirica seed kernel). The elemental composition of T. bellirica was determined by ICP-OES. Macro elements like Ca (calcium), Na (sodium), and K (potassium) were found to be abundant in the studies samples. The quantity of Ca, Na, and K in the aqueous extracts of T. bellirica fruit, finished products of T. bellirica, alcoholic extract of T. bellirica fruit, alcoholic extract of seed oil from T. bellirica nuts, and alcoholic extract of T. bellirica seed kernel was found to be (723.51-787.39, 347.80-478.90, 50.72, 120, and 300 mg/kg), (603.45-636.79, 241.76-370.00, 9.58, 180, and 200 mg/kg), and (151.23-165.73, 132.70-154.40, 4.26, 200, and 1,150 mg/kg), respectively. An Na/K ratio 1.0 is biologically relevant as a Ca/P ratio < 0.5 correlates with several health problems. The Ca/P ratio in the alcoholic extract of T. bellirica fruit was found to be 6.68. Hence, the measured Na/K and Ca/P ratios are in agreement with the recommended ratios. Our study supports the claims that T. bellirica extracts and finished products are of considerable therapeutic value for the prevention and/or treatment of various medical conditions. Moreover, the findings of our study will be helpful to ensure the quality and verify purification of natural products in different ayurvedic formulations
Durability Study of Basalt Fiber-reinforced Bars Exposed to Harsh Environments
No full textA Master of Science thesis in Civil Engineering by Mohamad Mazen Alrifai entitled, “Durability Study of Basalt Fiber-reinforced Bars Exposed to Harsh Environments”, submitted in April 2019. Thesis advisor is Dr. Farid Abed and thesis co-advisor is Dr. Tamer El Maaddawy. Soft and hard copy available.In this research, the durability of Basalt Fiber Reinforced Polymers (BFRP) bars of 10 mm diameter is studied after direct exposure to severe conditions. The main aim is to investigate the degradation performance of the microstructure and tensile properties of these BFRP bars under accelerated conditionings that simulate the concrete’s environment. A set of BFRP bars was wrapped by concrete prisms that were immersed in tap water. Another set of BFRP bars was exposed to alkaline solution. In concrete-wrapped and alkaline exposures, temperatures of 20oC, 40oC, 60oC were applied in isolated tanks for durations of 2880, 5760, and 8760 hours. The experimental program included Uniaxial Tensile Tests, Scanning Electron Microscopy (SEM), Water Absorption, Differential Scanning Calorimetry Analysis (DSC), Fourier Transform Infrared Spectrometry (FTIR), Matrix Digestion, and Fiber Volume Fraction Analysis. This combination of tests was selected to validate the tensile strength values. The output of these tests is a comprehensive microstructural characterization and tensile behavior evaluation before and after exposure to harsh environments. As a result, the effect of temperature was more distinct than the effect of exposure periods. Higher temperatures and greater durations in a harsh environment tend to cause impairments on the structural and microstructural levels. These impairments are represented by tensile loss, debonding, matrix loss, moisture impregnation, and micro-cracking at the fiber-matrix interface. Maximum tensile loss, moisture loss, and matrix loss were recorded to be 29%, 1%, 29.8%, respectively, for the samples that were conditioned for 9 months at 60oC in alkaline environment.College of EngineeringDepartment of Civil EngineeringMaster of Science in Civil Engineering (MSCE