成人VR视频

Description

High-speed droplet-solid impact testing has emerged as a method to test engineered surfaces in a manner that more closely matches the real-world scenarios said surfaces will be used in. In these tests, a surface is accelerated to high speeds and is timed to meet a falling droplet in the field of view of a high-speed camera. Much research is published on the results of high-speed droplet impact testing under ambient conditions. The experimental apparatus used in these tests employ some form of syringe tip to produce the droplet, which then falls downward to meet the accelerating surface. Droplet production with a typical syringe involves a burst of gas to overcome the solid-liquid surface tension force and dislodge the hanging pendant (often referred to as drop-on-demand, or inkjet, technology). This burst of energy introduces variability into the size, shape, and trajectory of the produced droplets. Further, any droplet impact tests in sub-freezing environments become extremely difficult, as the solid syringe introduces a solid surface upon which ice nucleation can occur, causing the liquid droplet to freeze. We have adapted an acoustic levitation device to allow for the handling of water droplets without the introduction of a solid surface. Proof-of-concept experiments show that droplets manipulated with the acoustic levitator have reproducible size, trajectory and shape. Installing the acoustic levitating device inside a cooling coil is hypothesized to allow for the supercooling of the levitating droplets, which would allow for high-speed droplet impact tests to be performed under conditions mimicking freezing rain.

Tasks

- understand the functioning of the acoustic levitator - design and build a cooling coil (heat exchanger) to integrate with the levitator - determine the achievable drop temperatures - calibrate the developed setup for different drop sizes - finally, integrate the drop generation setup with the drop impact apparatus

听

Number of positions

1

Academic Level

No preference

Description

The Nepenthes pitcher plant is a carnivorous plant that is said to teach insects how to 鈥渋ce-skate鈥� just before digesting them. This plant, or more precisely its highly lubricated surface, has triggered considerable biomimetic effort in creating similarly slippery and omniphobic surfaces (named SLIPS) with application in fields where non-wetting and anti-icing properties are desired. Thereby, the porosity of a substrate鈥檚 surfaces is what holds the lubricant in place. We have recently shown that femtosecond (fs) laser irradiation of polymer surfaces produces novel porous topologies with multi-scale roughness. Further, we have established the mechanisms behind the formation of femtosecond laser-induced porous structures and the parameters that control their dimensions. In fact, it turns out that the average molecular weight of the polymer is the key factor in the resulting pore size. In this project we want to explore the surface wettability of polyethylene with surface porosity resulting from femtosecond laser micromachining. Test liquids of different surface tension will be chosen with the long-term goal of fabricating extremely wetting and non-wetting surfaces.

Tasks

- prepare polymer sheets from powder using a hot press process - micromaching the polymer sheets with a femtosecond laser - assess the wetting properties of the produced surfaces by contact angle measurements with different liquids

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Number of positions

1

Academic Level

Year 2

Description

Rebuilding human tissues requires multidisciplinary engineering strategies to design the material itself, as well as the tissue engineering process that goes with it. If we can understand how cells dynamically work in tissues, we can encourage them to behave in desirable or 鈥渉ealthy鈥� ways, and address biomedical challenges in developing new therapies, rebuilding tissues to act as replacements in the body, or develop better tools to identify improved drugs. In this project, we will investigate how designing the dynamic properties of non-cell component of tissues will affect cell function. 鈥淪mart materials鈥� respond to applied stimuli, and can be microfabricated into tissue scaffolds to watch cell activity. These materials can be used to change the mechanical properties, composition, and tissue architecture presented to cells, to model various aspects of disease progression. This designer materials will be initially be used to study cancer progression; but more importantly, this project will develop new tools and knowledge needed to engineer a wide variety of artificial tissues and organs.

Tasks

The student will gain experience in materials processing, characterization, cell culture, and microscopy; and this project will require students to work across disciplines and collaborate closely with materials scientists, engineers, and biologists. Solving these broad problems requires highly-motivated, independent and driven individuals, who are unafraid to learn new fields and try new techniques

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Number of positions

3

Academic Level

Year 3

Description

Rebuilding tissues on a dish in the lab allows us to watch in high-resolution how cells orchestrate tissue progression through development, homeostasis and disease. However, cells are typically cultured on hard, flat, plastic devices that look nothing like the environment cells would see inside the body. In our lab, we build miniaturized organs 鈥渙n a chip鈥�, using microfluidic and microfabrication strategies to create culture conditions that replicate dynamic features of organs. For example, the breathing process of lungs generates a cyclic stretch which affects how lung tissues function, and we build a miniaturized bioreactor that recreates the breathing motion, while allowing us to look very closely at cells in these realistic tissues. The students involved in these projects will develop microengineered bioreactors capable of recreating dynamic culture conditions present in cancer, the placenta, and the brain, using an interdisciplinary and integrative engineering approach. These bioreactors will ultimately be used to identify high-value therapeutic strategies for further study and development.

Tasks

The student will gain experience in microfabrication, cell culture design, simulation, cell culture, and microscopy; and this project will require students to work across disciplines and collaborate closely with biologists. Solving these broad problems requires highly-motivated, independent and driven individuals, who are unafraid to learn new fields and try new techniques

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Number of positions

2

Academic Level

Year 2

Description

Approximately 12% of worldwide mortality is directly linked to coronary artery disease, characterized by narrowing of the arteries nourishing the heart. This necessitates the implantation of a vascular stent, a cylindrical mesh that is implanted in the narrowed area to allow maximum blood flow. Due to biocompatibility issues, the stented artery can re-narrow, putting the patient at risk of heart attack and myocardial infarction. Endothelial cells create the most biocompatible blood contacting surface known to man. Modifying the surface of stents with specific biomolecules can potentially enhance the endothelial coverage of the stent. The biomolecules would target the recruitment of endothelial progenitor cells (EPCs) to the surface, protecting against stent failure and causing regeneration of the arterial tissue. The stents we are interested in are biodegradable stents made from polylactic acid (PLA). The objective of this project is to develop a realistic in vitro stent model that will be used to optimize surface modification strategies. Specifically, the goal of the internship project is to optimize a PLA-based tubular system that can be biofunctionalized and tested under flow conditions to study cell recruitment. The results of this work could play a key role in designing a new generation of surface modified vascular scaffolds that has superior long-term performance.

Tasks

Develop micro-design of a vascular stent (CAD); optimize and produce biodegradable tubular flow models; test flow dynamics of tubular models; cell culture; fluorescence microscopy; image analysis, experimental design; data analysis; data presentation at group meetings; collaboration with research groups in chemical engineering and medicine at 成人VR视频, Universit茅 Laval, and the Montreal Heart Institute.

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Number of positions

1

Academic Level

No preference

Description

Immunotherapy using engineered and cultured immune cells has the potential to revolutionize the treatment of cancer. The principle of immunotherapy is to 鈥渢rain鈥� immune cells to detect and attack cancer cells specifically. One approach used in our lab is to harvest monocytes from blood and differentiate these cells into dendritic cells in culture vessels. These dendritic cells can then be injected into patients to activate an immune response against a specific cancer cell type. The efficacy of this approach is however highly dependent on the manufacturing process used to culture and manipulate immune cells in vitro, including culture surfaces and culture media. Culture media currently used in cell processing laboratories contain proteins that adsorb onto culture surface, which impacts cell adhesion and immunotherapy product quality. In the context of current good manufacturing practice, dendritic cell immunotherapy products are cultured in specific animal component-free media containing proteins such as albumin, transferrin and insulin. The objective of this project is to quantify protein adsorption to different cell culture surfaces, and to study the impact of these proteins on cell adhesion. This project will be conducted in collaboration with a company involved in the development of products used to manufacture therapeutic cells. The results of this project will help develop better cell manufacturing devices for medical applications such as cancer immunotherapy. Note: please corinne.hoesli [at] mcgill.ca directly (cover letter, CV, transcript) before submitting your SURE form.

Tasks

The trainee will measure and quantify the amount and the nature of the protein adlayer adsorbed on the surfaces developed in the laboratory, develop techniques to visualize cell interactions with the surface and develop a protocol to block cell adhesion receptors. The trainee will also participate in bi-weekly meetings with our industrial collaborator.

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Number of positions

1

Academic Level

No preference

Description

Type 1 diabetes is an autoimmune disease in which the insulin-producing beta cells of the pancreas are destroyed. To regulate blood glucose levels, most type 1 diabetic patients require several daily doses of exogenous insulin. Islet transplantation has emerged as an alternatie long term treatment to insulin therapy: instead of replacing insulin, the insulin-producing beta cells found in clusters called islets of Langerhans are isolated from donors and administered to patients. Currently, this treatment can eliminate the need for insulin injections in 40% of type 1 diabetic recipients for at least 3 years. Unfortunatly, the islet supply from human donors is vastly insufficient to treat all type 1 diabetic patients. Also, recipients must take immune suppressive drugs for the rest of their life to limit graft rejection. The long-term goal of this project is to develop a transplantation device allowing the transplantation of stem cell-derived islets while avoiding the need for immune suppression. Currently, our device consists in a vessel irrigated by vessels created using 3D printed carbohydrate glass (sugar) lattices. The objective of this project will be to optimize the coating applied to the 3D printed carbohydrate glass networks, including preliminary thrombogenicity tests in animals. This project is expected to lead to the design of an improved islet transplantation device to treat diabetes. Note: please e-mail corinne.hoesli [at] mcgill.ca directly (cover letter, CV, transcript) before submitting your SURE form.

Tasks

Aseptic cell culture of beta cell lines and primary islets; carbohydrate glass casting, coating & characterization (e.g. thickness, permeability, thrombogenicity); participation in animal studies; literature search; design of experiments; data analysis; oral and written presentation of results; presentation of research progress in bi-weekly JDRF team meetings; contribution to lab duties.

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Number of positions

2

Academic Level

No preference

Description

Catalytic Process Engineering (CPE) laboratory is engaged in the development and understanding of catalyzed processes and reactor engineering concepts dedicated to sustainable energy conversion technologies. In detail, we focus on the synthesis of novel catalysts for the direct non-oxidative methane conversion to valuable chemicals as as well CO2 conversion to renewable natural gas. The UG student will work closely together with PhD students.

Tasks

1. Catalyst preparation 2. Catalyst characterization 3. Catalyst activity measurements 4. Data analysis and kinetic modeling.

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Number of positions

1

Academic Level

Year 2

Description

The properties of self-healing materials have long fascinated polymer scientists and have increasingly been the focus for any application requiring re-forming after mechanical fracture. This is obviously a desirable property for coatings. Dynamic covalent linkages will be the mode used for self-healing in this project via retro Diels-Alder chemistry via furan/maleimide coupling. Here, furanyl:maleimide ratios will be varied and scratch tests will be performed in conjunction with evaluation of temperature required for retro Diels-Alder for our base formulation. If lower temperatures are required, boronic ester exchange catalyzed only with moisture will be attempted using commercially available monomers introduced into the copolymer.

Tasks

The student is expected to learn how to synthesize polymers with self-healing functionality as well as to characterize the resulting materials for composition and chain length and conditions required for self-healing.

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Number of positions

1

Academic Level

No preference

Description

The project's goal is to eliminate the use of toxic diisocyanates in polyurethane sealant/coating materials (non-isocyanate polyurethanes (NIPUs)) using sustainably sourced feedstocks as much as possible. New NIPUs will be formulated and tested with emphasis on curing chemistry to obtain the desired mechanical properties.

Tasks

The student will learn how to make monomers from renewable feedstocks and then make polyurethanes and perform curing and rheological tests of the resulting formulation.

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Number of positions

1

Academic Level

No preference

Description

Nanomaterials (NMs) are natural or artificial materials with a feature that is on the scale of 1 to 100 nm in at least one dimension. These small features grant novel and useful optical, electrical and mechanical properties. As a result, nanomaterials are now used in applications that span all sectors from energy to medicine and can even be found in commercial products such as cosmetics, textiles and paints. However, like many other products, NMs are eventually released into the environment where their impact on ecosystems and human health remains largely unknown as toxicity data is scarce. The majority of available toxicity studies focus on marine organisms and indicate that nanoparticles can readily pass through biological barriers and accumulate in tissues and organs of exposed organisms, triggering physiological distress, diminished reproductive fitness and early mortality. In contrast, research on the effects of NMs in the terrestrial environment is limited. The main goal of this project is to produce toxicity data on NMs from a commercial product in terrestrial organisms and identify toxicity mechanisms in a well-established model.

Tasks

The student will be introduced to the field of nanotoxicology by being trained to perform standard toxicity tests in addition to material characterization techniques including hyperspectral microscopy and dynamic light scattering. After receiving the required training in the lab (first month), the student will start working more independently to perform a series of acute toxicity tests.

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Number of positions

2

Academic Level

No preference

Description

Engineered microstructures (EMs) are being increasingly incorporated into commercial products in many different industries including pharmaceuticals, cosmetics, and environment protection. The primary driver for EM use is related to their special properties that set them apart from their bulk counterparts, such as increased catalytic, optical, magnetic or electronic capacity. Graphene-based microstructures are one of the most popular structures in several different applications, due to their outstanding specific surface area. Much research has been carried out to optimize the properties of graphene-based structures, to date. Some processes such as functionalization of the surface or embedding graphene sheets into polymers or other matrices are known to improve the desired properties of these EMs. The primary objectives of this project are to develop novel graphene-based engineered microstructures to be utilized in removal of emerging contaminants from the wastewater.

Tasks

The student will be trained in a range of nanotechnology and analytical/laboratory techniques that will include, for example: graphene oxide synthesis, dispersion and EM processing, determination of aggregate size via dynamic light scattering, and assessment of EM adsorption capacity via laboratory batch and column tests. After receiving the required training in the lab (first month), the student will start working more independently. The student will be introduced to a range of new areas including colloidal chemistry, aggregation theory, and environmental nanotechnology.

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Number of positions

1

Academic Level

No preference

Description

Wastewater treatment plants are an important source of microplastics through discharge of treatment effluent. However, the fate of such released microplastics is not yet well known. The objective of this project is to evaluate the effect of UV weathering on microplastics properties. Two weathering states will be studied: pristine and weathered after 6 months of exposure in a controlled UV weathering chamber. The properties of pristine and weathered microplastics will be compared.

Tasks

The student will be in charge of conducting sorption experiments including preparation of microplastics and contaminant solutions, setting up and monitoring the sorption tests, and sampling. The student will be involved in monitoring the progression of weathering and contaminant sorption behavior on the microplastics.

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Number of positions

1

Academic Level

No preference

Description

Wearable devices can allow for continuous or on-demand monitoring of someone鈥檚 condition, health and surrounding environment in a non-invasive manner. Biocompatible lightweight materials could be incorporated in clothing or worn directly onto the skin. While biosensors and wearable electronics have become more and more portable in the past decade, challenges remain, such as the production cost, the design of biocompatible interfaces between biological tissues and electronics, and the ease of use. In order to produce entirely biocompatible and biodegradable wearable items in an environmentally-friendly manner, here we propose to fabricate protein-based wearable materials. Proteins can serve two functions as part of wearable devices; 1) they can act as a biopolymer scaffold that holds the material together, and that confers its flexibility and mechanical properties, 2) they can simultaneously act as the sensing or responsive element in the device. There exist several self-assembling proteins that can be used to form protein fibers, self-assembling gels, or other three-dimensional matrices. This project aims at identifying biocompatible protein candidates that can be used as matrix for the fabrication of wearable devices, and at developing methods to easily produce functional protein patches.

Tasks

The student will be involved in all steps of the fabrication process of protein-based materials; from the rational design of proteins and genetic engineering portion, to the protein production, purification, and materials assembly. If time permits, the student will contribute to the design of a functional device.

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Number of positions

2

Academic Level

No preference

Description

Soft and biocompatible materials capable of electron transfer are attractive for several applications, including biosensors, electrobiosynthetic systems, flexible electronics and low-cost energy conversion and storage devices. Using proteins and peptides to fabricate soft electronics allows for the production of multifunctional bioactive and environmentally-friendly devices. This project aims at modifying proteins that self-assemble into nanofibers to confer them with novel functionalities such as electron transport or light harvesting. These engineered conductive or light-sensitive fibers can then be used to fabricate functional coatings or thin films, and can be incorporated into devices like batteries and solar cells. Modifications of the protein fibers will be carried out through genetic engineering, self-assembly with nanomaterials, or covalent bioconjugation reactions. The electrical and optical properties of the protein nanofibers will then be characterized under different conditions.

Tasks

The student will be involved in all steps of the fabrication process of protein-based materials; from the rational design of proteins and genetic engineering portion, to the protein production, purification, and electrical/optical characterization. If time permits, the student will contribute to the design of a functional device.

听

Number of positions

2

Academic Level

No preference

Description

Water is one of the most significant compounds in nature that is not only responsible for life but also plays a significant role in many processes related to energy and safety. Water can undergo two significant phase changes when it is exposed to the proper thermodynamic conditions and components: Ice and Gas Hydrate. Ice accretion on modern infrastructure such as aircrafts, ships, offshore oil platforms, wind turbines, telecommunications and power transmission lines jeopardize their integrity and pose a significant safety hazard to operators and civilians alike. Gas hydrates on the other hand, are viewed as a new/alternative method to sustain our increasing energy demands and hence, our quality of life. Naturally occurring gas hydrates have enormous amounts of stored energy that exceeds conventional carbon reserves and mostly contain natural gas. Rheometry experiments will provide a unique insight into the flow of water, in a liquid state, but also as a slurry with soft-solids (ice and hydrate). This information is essential for the design of safe, economical, and environmentally responsible processes and facilities to deal with ice and hydrate-forming systems, as well as for the exploitation of in-situ methane hydrate as a future energy resource. A novel approach will be undertaken in this work, exploring the effects of nanomaterial surfaces and polymeric additives on both ice and gas hydrate forming systems. The goal is to elucidate the behavior of the flow of water in the presence of these surfaces and additives as it transitions to either ice or hydrate. The outcome of such work has the potential to place Canada at the forefront of technologies related to de-icing techniques that preclude ice accretion and natural gas recovery, storage and transportation.

Tasks

The student should have a strong background in multi-phase thermodynamics and crystallization processes. He/she will design and carry out experiments related to ice and gas hydrate nucleation, both at atmospheric and high pressures and measure rheological properties. The student will investigate the effect of various factors, such as degree of sub-cooling and inhibitor addition, that influence the rheology of the phase change. He/she will work closely with a graduate student on this project but must also be able to work independently and diligently.

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Number of positions

2

Academic Level

No preference

Description

Surface engineering is used to selectively tailor the surface properties of materials (to render it hydrophobic or hydrophilic, for example) without affecting the desirable bulk properties (low cost, good mechanical properties, resistance to corrosion and durability). Cold reactive plasmas (ionized gases produced by an electrical discharge) have been used to alter a surface by the addition of functional groups or a functional layer. Plasma deposited organic coatings have been deposited on a wide range of solid surfaces. However, hydrogels, which are used directly in several applications or that could be used as models for food related applications, have had less attention. The project will involve the investigations of a methodology for the preparation of plasma deposited organic coatings on hydrogels and their surface chemical characterization. The candidate should demonstrate scientific curiosity as well as maturity and autonomy.

Tasks

- Deposition of thin organic coatings using plasma technology. - Surface analysis and characterization of the deposits - Literature search

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Number of positions

1

Academic Level

No preference

Description

This project for the first time combines CO2-conversion-into-fuels and biomass-upgrading through an electrochemical system. This efficient system addresses the issues of energy consumption and CO2 mitigation via a single unified goal: The efficient conversion of intermittent renewable energy into stored chemical energy. Electrochemical CO2 reduction reaction (CO2RR) holds promise for energy conversion by providing relatively high energy conversion efficiency. Very selective cathode electrocatalysts for CO2RR have been recently developed, but the practical realization of this reaction still requires the development of electrocatalysts and new electrochemical systems that require low overpotentials. A big portion of the overpotential comes through the counter electrode reaction (i.e. oxidation reaction in anode) which is currently oxygen evolution reaction (OER) with oxygen as the product. In this project we aim to replace OER with biomass upgrading, to not only decrease the total overpotential of the electrochemical system, but also to produce more valuable chemicals in the anode side rather than oxygen.

Tasks

The project has 2 parts: experiment and computation Part 1) Students will run electrochemical reactions including CO2 reduction reaction in cathode and biomass upgrading in anode within a single homemade electrochemical cell. They will need to optimize the reaction conditions such type and concentration of the electrolyte, membrane type, and applied voltage to achieve the highest energy conversion efficiency. Part 2) Students will run quantum chemistry computation to study different electrocatalysts for these two cathodic and anodic reactions. The goal of these computation is to discover new electrocatalysts with superior catalytic activity and selectivity and also to shed light on our understanding of the reaction mechanism on each electrocatalyst.

Number of positions

2

Academic Level

No preference

Description

Various strategies can be used to minimize exposure of human and aquatic organisms to environmental contaminants. Two of our on-going research projects approach this issue from different perspectives. The first project aims at integrating ozone treatment with biological treatment to improve the overall performance of wastewater lagoon treatment for remote and First Nations communities in order to reduce discharges of contaminants in receiving waters, to protect the ecosystem as well as the quality of our water resources. The objective of the second project is to determine the extent to which humans are exposed to legacy and replacement compounds, such as phthalates and their replacements, through drinking water and to evaluate the efficiency of drinking water treatment technologies in minimizing exposure to environmental contaminants. These two projects offer an opportunity to be familiarized with various environmental issues, sampling procedures and sample preparation methods and to learn different ways of assessing the quality of water.

Tasks

The student will first get familiarized with the background information as well as the context of these projects, then will be trained on the various sample collection, preparation and analysis methods relevant to the projects, which will later be applied to the samples collected. The student will work in close collaboration with the team members to develop an experimental plan for the summer. The student will also participate in weekly research meetings and on a regular basis exchange with members of the other research groups involved in these projects, including our industrial partner.

Number of positions

2

Academic Level

Year 2