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Western University

2013

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Articles 151 - 164 of 164

Full-Text Articles in Engineering

A Dual-Rate Model Predictive Controller For Fieldbus Based Distributed Control Systems, Mohammad Arif Hossain Feb 2013

A Dual-Rate Model Predictive Controller For Fieldbus Based Distributed Control Systems, Mohammad Arif Hossain

Electronic Thesis and Dissertation Repository

In modern Distributed Control Systems (DCS), an industrial computer network protocol known as fieldbus is used in chemical, petro-chemical and other process industries for real-time communication between digital controllers, sensors, actuators and other smart devices. In a closed-loop digital control system, data is transferred from sensor to controller and controller to actuator cyclically in a timely but discontinuous fashion at a specific rate known as sampling-rate or macrocycle through fieldbus. According to the current trend of fieldbus technology, in most industrial control systems, the sampling-rate or macrocycle is fixed at the time of system configuration. This fixed sampling-rate makes it …


Smouldering Combustion For Soil Remediation: Two-Dimensional Experiments And Modelling, Tanzeer Hasan Feb 2013

Smouldering Combustion For Soil Remediation: Two-Dimensional Experiments And Modelling, Tanzeer Hasan

Electronic Thesis and Dissertation Repository

Sustaining Treatment for Active Remediation (STAR) is a novel technology for the remediation of soils contaminated with Non-Aqueous Phase liquids (NAPLs). STAR is based upon the concept of liquid smouldering, in which NAPLs embedded in a porous medium are progressively destroyed via an exothermic oxidation reaction which propagates in a self-sustaining manner through the contaminated material. The In Situ Smouldering Model (ISSM), developed to simulate the propagation of STAR as a function of NAPL content and local air velocity, was calibrated for a suite of one-dimensional experiments (MacPhee et al., 2010). However, STAR application at field sites involves propagation of …


Ph Responsive Hydrogen Bonding Motif To Improve The Sensitivity Of Tumor Imaging, Fatimah Mohammed Algarni Jan 2013

Ph Responsive Hydrogen Bonding Motif To Improve The Sensitivity Of Tumor Imaging, Fatimah Mohammed Algarni

Electronic Thesis and Dissertation Repository

Magnetic resonance imaging (MRI) is a powerful non-invasive medical diagnostic technique. Superparamagnetic iron oxide nanoparticles (SPIO) are effective contrast agents and provide high sensitivity contrast in MRI. Recent research has demonstrated that nanoparticle clusters exhibit significantly higher relaxivity than individual nanoparticles.

In order to increase the sensitivity of tumor imaging, supramolecular chemistry was introduced to this field and a novel conjugation method was developed using click chemistry between azide functionalized nanoparticles and pH-sensitive hydrogen bonding building blocks. This pH-sensitive hydrogen bonded complex was synthesized to cluster nanoparticles under mildly acidic biological conditions.

Due to the unexpected X-ray crystal structure of …


Concrete Bridge Girders With Exposed Flexural Reinforcement, Trevor K. Scott Jan 2013

Concrete Bridge Girders With Exposed Flexural Reinforcement, Trevor K. Scott

Electronic Thesis and Dissertation Repository

Reinforced concrete highway bridge girders are regularly repaired by replacing deteriorated concrete with new concrete, temporarily exposing the flexural reinforcement. The absence of bond between the concrete and steel at this stage makes it difficult to compute the flexural capacity and the current code criteria provide no guidance to assist practitioners.

The research reported in this thesis rectifies this knowledge gap. A thorough examination is presented of experimental and analytical investigations by others to determine the typical behaviour, including probable failure modes, of reinforced concrete specimens with exposed flexural reinforcement. Based on these findings, two analytical approaches are developed to …


Simplified Tools For Performance-Based Design Of Reinforced Concrete Frames Exposed To Fire, Salah El-Din F. El-Fitiany Jan 2013

Simplified Tools For Performance-Based Design Of Reinforced Concrete Frames Exposed To Fire, Salah El-Din F. El-Fitiany

Electronic Thesis and Dissertation Repository

Fire safety of Reinforced Concrete (RC) buildings is an important design aspect that ensures structural integrity during fire events. As new codes are moving towards performance based design, practitioners are in need of rational design tools to assess the strength and serviceability of individual RC elements and the structure as a whole during fire. This thesis provides such tools for RC frames.

A previously developed sectional analysis method is extended to cover RC beams subjected to fire from three sides. An extensive parametric study is conducted to evaluate the equivalent stress-block parameters at elevated temperatures.

A novel method to track …


Self-Cleaning Polyurethane And Polyester Coatings, Yixing Tang Jan 2013

Self-Cleaning Polyurethane And Polyester Coatings, Yixing Tang

Electronic Thesis and Dissertation Repository

Self-cleaning titanium dioxide (TiO2) based polyurethane and polyester nanocomposites were synthesized, characterized and tested in this thesis. A monomer functionalization method (“grafting from” polymerization) was used for synthesizing both novel nano-TiO2 coordinated polyurethanes (nano-TiO2-PU) and nano-TiO2/polyester nanocomposites. This technique provides the advantage of directly attaching nanoparticles to the polymer backbone.

For polyurethane synthesis, two different methods (one-shot and pre-polymer) were explored. Using several characterization techniques, product from the pre-polymer method showed better mechanical properties; therefore, the pre-polymer method was chosen for subsequent nano-TiO2-PU synthesis. In the nano-TiO2-PU synthesis, the …


Precast Deck Joints Using Frp And Ultra-High Performance Concrete, Augustine K. Banson Jan 2013

Precast Deck Joints Using Frp And Ultra-High Performance Concrete, Augustine K. Banson

Electronic Thesis and Dissertation Repository

The need for rapid construction or replacement of highway bridge decks can be addressed by precast concrete elements reinforced with Glass Fiber Reinforced Polymer (GFRP) bars with cast-in-place joints made using Ultra-High Performance Concrete (UHPC). This thesis investigates the bond between GFRP bars and UHPC and splice length optimization to obtain narrow joints and simplified bar geometries. Multiple linear regression analyses of existing bond data indicate that the bar’s Young’s Modulus and embedded length are the most significant parameters that influence the average bond strength of sand-coated GFRP bars in UHPC: increasing either decreases the average bond strength. Linear-elastic uncracked …


Engineering Nanocomposites For Antimicrobial Application, Binyu Yu Jan 2013

Engineering Nanocomposites For Antimicrobial Application, Binyu Yu

Electronic Thesis and Dissertation Repository

In this thesis, active and passive antimicrobial methods have been applied to fabricate antifouling surfaces. In the first study, we reported the synthesis and characterization of neat TiO2 and Ag-TiO2 composite nanofilms prepared on silicon wafer by sol-gel method. The synthesized Ag-TiO2 thin films showed enhanced bactericidal activities compared to the neat TiO2 nanofilm both in the dark and under UV illumination. The advantage of Ag-TiO2 nano-composites is to expand the nanomaterial’s antibacterial function to a broader range of working conditions. In the second study, we reported the synthesis, characterization and environmental application of nitrogen …


Batch And Continuous Studies Of Chlorella Vulgaris In Photo-Bioreactors, Claudia Sacasa Castellanos Jan 2013

Batch And Continuous Studies Of Chlorella Vulgaris In Photo-Bioreactors, Claudia Sacasa Castellanos

Electronic Thesis and Dissertation Repository

Microalgae are unicellular, photosynthetic microorganisms, they have minimal nutrient requirements and are being used as source materials for a variety of products such as protein rich nutritional supplements, pharmaceutical chemicals and pigments (used in food and cosmetics). They also grow extremely fast, in comparison to plants and many microalgae strains are exceedingly rich in oil which makes them great candidates for the production of biodiesel. The strain Chlorella vulgaris, has shown a great promise as a source of oil and as being able to help in the treatment of wastewater. Despite all the advantages , the high cost of …


Developing Electrochemical Biosensors For Point-Of-Care Diagnostics Of Cardiovascular Biomarkers, Yang Cheng Jan 2013

Developing Electrochemical Biosensors For Point-Of-Care Diagnostics Of Cardiovascular Biomarkers, Yang Cheng

Electronic Thesis and Dissertation Repository

Troponin is known as a type of reliable biomarker for the detection of cardiac disorders. Cardiac troponin I (cTnI), as a subunit of troponin, is highly sensitive to cardiac injury; therefore, the cTnI level is used as an index to diagnose myocardial damage, particularly acute myocardial infarction. It can be also used in cardiospecific diagnosis, risk stratification therapeutic treatment and post risk management. In this research, an amperometric immunosensor was developed based on planar electrode and sandwich ELISA format. The electrical response corresponding to biological information was obtained via four main procedures, including electrode modification, immunoreaction, signal amplifications and amperometric …


Change In Pore Size Distribution Of Compacted Soil Layers And Its Effect On Solute Breakthrough Curves, Sara Karimi Jan 2013

Change In Pore Size Distribution Of Compacted Soil Layers And Its Effect On Solute Breakthrough Curves, Sara Karimi

Electronic Thesis and Dissertation Repository

It is often useful to predict contaminant migration from waste containment systems, such as landfills, as part of the assessment of the overall impact of such systems on the receptor environment. In many instances, material properties, for example, those of the liner, are assumed to be constant. This study was conducted to evaluate the accuracy of considering constant material and transport parameters in the modelling of sodium and chloride breakthrough curves through a compacted soil layer using the commercial software, Pollute v.7. Experiments were conducted with three different mixtures of glass beads and varying amounts of kaolinite (30, 40 and …


Development Of Novel Nano-Structured Materials With Low-Cost And High Stability For Pem Fuel Cell, Dongsheng Geng Jan 2013

Development Of Novel Nano-Structured Materials With Low-Cost And High Stability For Pem Fuel Cell, Dongsheng Geng

Electronic Thesis and Dissertation Repository

Polymer electrolyte membrane fuel cells (PEMFCs) are non-polluting and efficient energy conversion devices that are expected to play a dominant role in energy solutions of the future. However, due to high cost and known degradation issue of Pt electrocatalyst, more durable, efficient, and inexpensive electrocatalysts are required before fuel cells can become commercially viable. This research is revolving around the development of electrocatalysts such as non-noble metal oxygen reduction reaction (ORR) catalyst, new alternative supports, and novel Pt nanostructures to address the above-mentioned challenges in PEMFCs.

Firstly, we report the synthesis of nitrogen doped carbon nanotubes (CNx) and …


Vibration And Buckling Of Carbon Nanotube, Graphene, And Nanowire, Mohammad Hadi Mahdavi Jan 2013

Vibration And Buckling Of Carbon Nanotube, Graphene, And Nanowire, Mohammad Hadi Mahdavi

Electronic Thesis and Dissertation Repository

Nanostructured materials with superior physical properties hold promise for the development of novel nanodevices. Full potential applications of such advanced materials require accurate characterization of their physical properties, which in turn necessitates the development of computer-based simulations along with novel experimental techniques. Since controlled experiments are difficult for nanoscale materials and atomic studies are computationally expensive, continuum mechanics-based simulations of nanomaterials and nanostructures have become the focal points of computational nano-science and materials modelling.

In this study, emphasis is given to predicting the mechanical behaviour of carbon nanotube (CNT), graphene, nanowire (NW), and nanowire encapsulated in carbon nanotube (NW@CNT), which …


Tornadoes In Canada: Improving Our Understanding, David Sills Jan 2013

Tornadoes In Canada: Improving Our Understanding, David Sills

Goderich August 21 2011 F3 Tornado Associated Files

Environment Canada presentation at ICLR

  • What is a tornado?

  • How do tornadoes form?

  • How are tornadoes rated?

  • Where / when do tornadoes occur?

  • How does EC provide tornado alerts?

  • Are tornadoes in Canada increasing in frequency and/or intensity?