B2C web sites experience large sales volumes during the period prior to major gift giving occasions. The more sophisticated web sites often utilize 20 or more web services while processing orders. If one or more web services fail during these high volumes periods, it can have a significant negative impact on the profitability of the web site. The goal of this project is to construct a JAVA-based infrastructure that adapts to web service failures so that the order taking can proceed regardless. (This project is for an Industrial Engineering student specializing in Information Engineering, with strong JAVA programming skills.)

Company X is building a prototype of a service that will provide multi-media-based communication via the web. The purpose of this project is twofold: (i) To evaluate the web site's User Interface design based on wireframes, and (ii) Design and conduct an experiment to evaluate the web site's User Interface as implemented in the prototype. Wireframes will be available January 27th and the prototype will be available February 21st. (This project is for an Industrial Engineering student specializing in Human Factors.)

Research in laser photoacoustic diagnostics of bone osteoporosis detection. For more information, consult www.cadift.mie.utoronto.ca.

Development of a Facility for Advanced Biophotoacoustics: The Photoacoustic Radar, a scanning tomographic technology for early detection of breast cancer. For more information, consult www.cadift.mie.utoronto.ca.

Development of novel diffusion-wave imaging and other diagnostic techniques for industrial quality control of optoelectronic materials and devices, primarily silicon, thin-film and quantum dot solar cells. For more information, consult www.cadift.mie.utoronto.ca.

A Technology for Non-Contact Hardness and Case-Depth Inspection of Industrial Steels using Laser infrared Photothermal Radiometry (PTR). For more information, consult www.cadift.mie.utoronto.ca.

One major problem in aircraft safety is bird strike. The bird is digested in the engine during take-off or landing. This results in local and global damage to the aircraft and could lead to fatalities. The objective of this research is not only to evaluate that damage using finite element but also improve the fan design to accommodate birdstrikes. We have published numerous papers on this topic and we are interested in improving the material model for the striking birds as well as focus our attention to specific birds.

This study is motivated by the need to advance the concept of using mixing enhancement devices, such as chevron, to reduce jet noise. In spite of its current use in some engines, the impact of the concept of mixing enhancement to reduce jet noise remains unclear. For example, it is not clear how these devices impact jet noise and aero-performance. Furthermore, what is the effect of the number of chevrons along the jet axis, their length and angle for a given nozzle diameter and flow characteristics, upon vortex strength and ultimately noise reduction. Three aspects of the work are accordingly examined: (i) design and develop novel modular morphing chevrons using SMAs not only to reduce noise but also heat signature, (ii) develop a unified physics-based aero-thermo-acoustic prediction model that takes into account the morphed chevron geometric parameters, flow and thermal characteristics, and far-field noise, and (iii) test and develop functional prototypes capable of demonstrating the proof of concept, its strength, challenges and the associated costs.

The field of shape morphing aircraft has attracted the attention of hundreds of research groups during the past century. Although many interesting concepts have been synthesized, only a handful of such reconfigurable planes have been ever produced (all of them supersonic and consisted of pivoting wings). In the range of low speed, small aircraft no commercial product exists to our knowledge. Although several conceptual designs of small or low speed aircraft has made it to the wind tunnel testing stage, only very limited number of such shape morphing prototypes have ever been fabricated or flight tested.In this project, we are trying to copy birds in the design of unmanned aerial vehicles. This project involves design, prototyping using intelligent materials such as shape memory alloys, and proof on concept via testing.

The objective of this research is to provide greater understanding of the complex phenomena that take place at the nanoscale level in multifunctional nano-tailored composites. Specifically, attention will be given to the research activities and achievements in my laboratory in developing multifunctional nano-tailored adhesive bonds for aerospace applications. In particular, we introduce this multifunctionality, and a certain level of intelligence, by homogeneously dispersing carbon nanotubes, and other nanofillers, into high strength thermoset epoxy adhesives. Application of molecular dynamics and atomistic based continuum techniques to treat this class of intelligent multifunctional materials will be discussed and their viability for in-situ diagnostics examined.

Recent development in and utilization of materials, fillers, devices, and systems with dimensions on the order of 0.1 to 100 nanometres, exhibiting novel and significantly enhanced mechanical, physical, chemical, and biological properties, due to their nanoscale size, are attracting considerable attention from the scientific community. Fundamental understanding of synthesis, processing, and characterization of nano-tailored materials will render greater opportunities for their ultimate deployment in aerospace engineering. It is anticipated that the role-played by nanotechnology in developing multifunctional intelligent materials to be of major significance to the industrialized nations. In this project, we rely on the homogeneous dispersion of nanofillers to improve the toughness of high strength aircraft grade adhesives. Both experimental and theoretical studies will be conducted to shed light on the mechanisms involved at this length scale.

Most recently, bead foams products are replacing traditional extruded foams used for packaging and cushioning applications, due to the ability to achieve very low densities and multi-directional, whereby the product orientation does not influence performance. Expandable polystyrene (EPS), expanded polyethylene (EPE), and expanded polypropylene (EPP) are three kinds of widely used modern moldable bead foams, which are produced by different methods. However, some specific applications require the material perform good thermal stability, high chemical resistance and excellent mechanical properties. As a result, high performance polymeric foams like PES, PEI, PPSU, PEEK etc. are attracting more attention. Compared to conventional polymeric foams, one of the main requirements in high-performance polymeric foams is the availability of being continuously used at high temperatures. Poly(ether ether ketone) (PEEK) is regarded as one of the highest performing materials in the world, which has generated much interest and applications in numerous industries, such as electronics, automotives, health care, oil-well, marine, and aircraft. In order to get the end products by bead foaming technology, the following procedure should be taken. Firstly, the PEEK beads foam is produced by a batching foaming process. The unfoamed PEEK pellet is put into a chamber, heated up to a desired temperature and annealed for a fixed time under high pressure. By releasing the system pressure, phase separation between the dissolved gas and the polymer matrix occurs, the PEEK foam beads are consequently achieved. Secondly, these expanded beads are later molded or shaped into various geometries as required by the applications using a molding machine in which sintering of the foamed beads occurs to manufacture the final products with proper shape using steam or high temperature air.

Expanded polymeric bead foams are widely used in many applications that require complicated shaping. Polyethylene terephtalate (PET) is a low cost engineering plastic with good mechanical and thermal properties. PET bead foaming holds great potential for many applications such as packaging, construction, transportation, and structural panels. This is due to its high heat deflection temperature and high crystallinity. The objective of this research work is to develop bead foaming technology for PET using batch autoclave and extrusion foaming process. The mechanical properties of expanded polymeric bead foams are greatly affected by interbead bonding during the steam chest molding process, which is highly dependent on the crystallization behaviour and the double peak structure of the polymer matrix during the foaming process. Therefore, the crystallization behavior of PET is investigated in this work to evaluate the double melting peaks structure, which would enable us to improve the sintering properties of PET beads in the steam chest molding process.

Polylactide (PLA) is one of the polymers that have increased interests due to its renewable sources, biocompatibility, biodegradability, acceptable mechanical and thermal properties. One of the most challenging issues these days is the crystallization behavior of PLA, which takes place very slowly and has a significant effect on manufacturing PLA bead foams. This structural parameter is highly important for polymer foaming and consequently for expanded PLA properties. In order to achieve high property PLA beads, the crystal melting should be much broader than normal peak or have double melting peaks. The first crystal melting peak is the result of defective crystal melts at lower temperatures and in bead structures that behave as fusing of individual beads and adhesion during the processing. However, the second peak protects the shape of foamed beads. Therefore, it is highly important to improve the PLA crystallization and hence the foaming properties in order to achieve high quality beads with well cohesion.

Bead foaming technology is the only known process that can manufacture ultra-low density polymeric foam products with complex three dimensional shapes. This technology is currently limited to only a few polymers such as expanded polypropylene (EPP), expanded polystyrene (EPS), and expanded polyethylene (EPE), which are inappropriate for high temperature applications. Thermoplastic polyurethane (TPU) with two phase microstructure of hard and soft segments arising from their thermodynamic incompatibility offer a very interesting potential for bead foam applications. In this research, the batch autoclave bead foaming technology is employed to investigate a new set of high temperature thermoplastic engineering polymers ETPU (Expanded thermoplastic polyurethane) with a significant potential to develop new products.

The project is concerned with development of advanced approaches to induce high degree of crystallization into PLA through foaming process by addition of nanoparticles in order to obtain high mechanical and thermal properties in this eco-friendly material. The long-term objective of this project is to utilize the synergistic effects of microcellular and nanocomposite technologies in the development of an industrially viable, cost-effective technology for manufacturing of microcellular PLA nanocomposites with superior properties as an eco-friendly material for packaging applications. This project focuses on: (i) A comprehensive study on rheological properties of PLA and PLA Nanocomposites in presence of supercritical CO2 in order to elucidate the rheological behavior of polymer/gas solution in relation with gas pressure, gas concentration and its plasticization effect and shear induced crystallization; (ii) Investigation of isothermal and non-isothermal crystallization behaviour of PLA in presence of nanoparticles and high pressure CO2. The results of these studies will be used in production of biodegradable microcellular foams with enhanced mechanical and thermal properties in cost-effective extrusion process.

Molecular weight of the material significantly affects the crystallization behaviour of the material. The hypothesis of this research is that the crystallization may also assist in cell nucleation. The main objective is to investigate the effect of molecular weight on polypropylene foaming with a goal of achieving largely expanded (more than 25 fold), high cell density (more than 10 billion cells/cm3), small cell sizes (10-30µm), and very soft non-crosslinked polypropylene foams. The long term goal is to make the 100% recyclable, non-crosslinked polypropylene foam sheets with high elasticity, high impact strength and high toughness.

Biocomposites made of wood fibers and polylactic acid (PLA) are sustainable and environmentally friendly. They are derived from renewable resources and have low carbon footprint, compared to petroleum-based composites. Therefore, the biocomposites are expected to be used in various application areas. However, both biofibers and PLA can degrade easily during the processing. Microcellular foaming technology and processing aids can mitigate the degradation as well as improve energy efficiency of the process. In addition, microcellular foaming technology can reduce the weight of products and the use of expensive PLA. The objective of this research is to develop a cost-effective extrusion foaming technology for wood fiber/PLA biocomposites using processing aids.

Although crosslinked polyolefin foaming technology has been well applied in industry, more fundamental and thorough studies are demanded to understand the mechanism, which can serve to improve the present technology. When the degree of crosslinking keeps increasing, the molecular mobility of the polymer chains is reduced, which will influence the thermal transitions of the polyolefins, such as glass transition temperature, melting temperature and crystallization. Further study is proposed on the effects of crosslinking on the thermal transition of EVA. This is important for analyzing the deformation of the crosslinked foams during the cooling stage, and especially for the high-expansion-ratio foaming of EVA with excessive amount of crosslinking degree.

Microfibrillated cellulose (MFC) includes cellulose fibers ranging in size from nano- to micro-scaled fibres. MFC is biodegradable and is derived from renewable resources. It has low density and high aspect ratio. The objective of this project is to develop the foaming technology to produce fine-celled MFC polymer composites. The composite foams will be obtained through the extrusion foaming process with different physical blowing agents. The effect of MFC content and processing parameters on the foaming behavior of composites will be investigated.

Nano celluloses, derived from renewable resources, are nano-sized, lightweight, and biodegradable fibers. These fibers have high aspect ratios and excellent mechanical properties. Therefore, reinforcement of polymers, especially biodegradable polymers, with nano celluloses has been a hot topic in the last decade. Despite the huge potential of this new type of composites, studies reported on the foaming of nano cellulose/polymer composites are very limited. The objective of the research is to understand the fundamental aspects of the effect of nano celluloses on the foaming behaviors of biodegradable polylactic acid (PLA) polymer and develop an industrially viable cost-effective processing technology for manufacturing uniform fine-celled nano cellulose reinforced PLA biocomposites. The value-added nano cellulose/PLA biocomposite foams will have great potential in the packaging and automotive applications by reducing material cost and environmental impacts.

Plastic fibers are used in a broad range of applications such as carpet fiber, fiber for blankets and cushion fillings, as well as lining material for fabrics. The most established technique to produce plastic fiber to date is the melt spinning process. As an effort to reduce production cost of plastic fibers, foaming process is to be integrated to an otherwise traditional melt spinning process to produce foamed fibers. The main challenge at hand is to produce low expansion high cell density foam while maintaining stretchability of the fibers in the manufacturing process.

Polymeric materials with micro/nanoscale features have been of interest in a wide range of applications including scaffolds for tissue engineering, foams for building insulation, and membranes for filtration. This project aims to develop novel strategies to introduce micro/nanoscale morphologies into the most commonly used thermoplastic: polypropylene. By incorporating a small amount of a surface-treated polytetrafluoroethylene additive in polypropylene, we have succeeded in preparing microcellular close-celled foams, open-celled foams, and rigid bicontinuous macroporous monoliths using conventional foam processing techniques. Our current focus is to develop strategies to reduce the amount of the modified polytetrafluoroethylene needed for the composite to adapt the unique morphologies and to test these structures for their suitability in various applications such as sound insulation.

The objective is to utilize the state-of-the-art microcellular injection technologies in an attempt to improve the properties and functionalities of bio-based and bio-degradable poly lactide acid (PLA) plastic foams and develop new viable applications for PLA in electronics, transportation and packaging industries. Different micro- and nano-composites of PLA along with different nucleating agents and injection techniques are examined. The work spans from the morphology investigation of produced foams to the evaluation of different properties such as mechanical, thermal, electrical, barrier and surface quality.

Injection Moulding of polymers is one of the most interesting production methods which is capable to produce polymeric parts with complicated geometries. Nowadays, mechanical properties of polymers have been improved by adding nano particles; for instance, nano-clay, nano-crystalline cellulose, carbon nano-tube. Moreover, by the advent of microcellular polymers, so many defects of the final thermoplastic products such as warpage and sink marks have been disappeared. In addition, this method has decreased the amount of consuming materials significantly. This project focuses on the production of microcellular nanocomposites by injection moulding methods with higher cell density, higher expansion ratio, uniform cell distribution, and smaller cell size.

While processing polymers in continuous systems such as extrusion or injection molding, melt fracture or processing instabilities can lower the quality of the output. Instead of smooth surfaces and straight extrudates, fractured surfaces and chaotic extrudates are generated. With the integration of foaming process, processing instabilities can appear dramatically more severe or be more prone to occurring. The project investigates the melt fracture behaviour of PLA; a biobased, biodegradable polymer. For foaming processes, the blowing agent type or content; or the die geometry, can all play an effect in promoting or supressing the melt fracture behaviour. Guidelines for the manufacturing foaming dies are being developed.

Open-cell foams refer to foams with interconnected cellular morphologies. Because of the unique morphologies, applications of open-cell foams are very versatile, including sound absorption, filtration, drug delivery, fluid absorption, etc. At present, majority of the open-cell foams are synthesized with thermosetting polymers that possess limited recyclability. The objectives of this project are to investigate cell opening mechanisms of recyclable thermoplastic polymers, and to develop novel strategies to promote cell interconnectivity and reticulation of these foam structures. Approaches such as the utilization of surfactants and polymer blends will be examined, and their influences on foaming behaviours and cell wall opening will be elucidated. Fundamental studies will be carried out with a lab-scale batch-foaming apparatus and will be transferred to an extrusion process. Cellular morphologies of the extruded foam structures will be optimized for sound and fluid absorption applications.

The primary goal of this research project is to investigate the development of innovative technologies for the fabrication of open-celled plastics through injection molding. The process of injection molding is cost-effective and has low manufacturing cycle time. However, due to certain intrinsic limitations of the process hitherto, injection molded open-celled plastic products available in the market are very limited. In the present work, strategies such as template-leaching and gas-assisted injection foam molding will be examined systematically using a lab-scale injection foam molding system. The influences of processing parameters and material compositions on the cellular morphologies of the injection molded foam will be studied and optimized for acoustic applications.

The pressure–volume–temperature (PVT) data for polymer/gas solutions is an important fundamental property of which accurate measurement has not been reported until recently. The diffusivity, solubility and surface tension are critical physical properties of polymer/gas systems for understanding and controlling polymer processing such as foaming, blending, extraction reaction and so on. However, the determination of these properties relies on accurate PVT data as a prerequisite. In this study, we will measure the PVT properties of various polymer melts saturated with high pressure gas at elevated temperatures.

The research revolves around the phenomenon of crystallization in Poly(Lactic acid) (PLA). PLA is biodegradable and biocompatible, PLA is used in many products including medical supplies. A high pressure DSC results illustrate the crystallization process occurring at certain conditions, the aim of the research is to identify crystallization process through the phenomenon of solubility with the use of a magnetic suspension balance (MSB). The results will then be compared to the data obtained through High pressure DSC. The findings from MSB will also be related to the visualization setup, to have a better understanding of the crystallization phenomenon.

The topic for my research work is “Development of novel thermoplastic foams-based acoustic insulation materials for industrial and automotive applications”. There are two main reasons for this study. First we want to develop new recyclable high quality sound insulation thermoplastic materials that can replace the current non-recyclable materials. And the second reason is to improve the efficiency of currently available sound insulation devices.

Traditional blowing agents (e.g., hydrochloroflorocarbons) in plastic foaming processes has been phasing out due to environmental regulations. Plastic foaming industry is forced to employ greener alternatives (e.g., carbon dioxide, nitrogen), but their foaming processes are technologically challenging. Moreover, to improve the competitiveness of the foaming industry, it is imperative to develop a new generation of value-added plastic foams with cell structures that can be tailored to different applications. In this context, the objective of this research is to achieve a thorough understanding on cell nucleation, growth, and deterioration phenomena that determine cell structures in plastic foaming processes. The core research strategy of this research is to develop and utilize innovative visualization systems to capture and study these phenomena. To be specific, three visualization systems have been developed to investigate foaming under both static and dynamic conditions. The dynamic systems are capable induce controllable extensional and shear strain to study the effects of stresses in plastic foaming to simulate conditions in industrial foaming processes, while the static system is key to establish baseline knowledge and to study critical processing parameters in an isolated manner. The wide range of future studies made possible by the visualization systems will be valuable to the development of innovative foaming technologies and foams.

Extensive experimental studies have been conducted to optimize the processing parameters in extrusion to achieve either high cell density foam with uniform structure or large expansion ratio foams. Since flow induces many changes in the nucleation mechanism and physical properties, the fundamental mechanisms of cell nucleation and growth are difficult to be fully understood especially when semi crystalline polymers are under investigation. Beside theoretical methods, visualization techniques have been widely employed to explain these fundamentals. The purpose of this project is to give a better understanding of fundamental phenomena of foaming using visualization chamber installed before the extrusion die. For instance, the effect of crystalline structure on the cell nucleation and expansion ratio of semi crystalline polymers can be investigated.

Cell nucleation and bubble growth are the most important steps governing the ultimate morphology and properties of foamed plastics. The goal of this research is to investigate fundamental mechanisms of cell nucleation and bubbles’ dynamics in foam injection molding by means of in situ visualization methods. Furthermore, foam microstructure formation and evolution will be mathematically modeled to simulate the phenomena during the mold filling stage in different foam injection molding techniques. A better understanding of aforementioned mechanisms will significantly help in determining the optimum processing conditions which will lead to the most appropriate microstructure for desired applications.

The project will have three parts: (i) erosion measurements using existing equipment, (ii) application of an existing erosion model to compare with the measurements, (iii) CFD modeling of the particle flows.

The goal of the project is to assist in the development of a new method of micro-machining of metals, ceramics and polymers using slurry jets. The work will involve both experimentation and modeling (analytical and numerical).

(co-supervised by Hani Naguib) The goal of this research project is to design and fabricate a microfluidic device to study the effect of fluid flow on the osteogenic differentiation of human mesenchymal stromal cell (hMSCs). Microfluidics devices allow fluids to be handled and analyzed at the micrometer scale. It has found many applications in biology in the fields of macromolecular analysis and cellular analysis. Multipotent mesenchymal stromal cells (MSCs) are a population of multipotent stem cells primarily isolated from the bone marrow. They are also found in other organs such as adipose tissue, muscle, liver, and umbilical cord blood. MSCs is a popular candidate for bone tissue engineering due to their multilineage differentiation potential and immunomodulatory properties. The design entails to design and fabricate a microfluidic device that is suitable for investigating the effect of fluid flow on hMSCs.