SURE: Chemical Engineering

Click on the title for full description of SURE 2017 projects in Chemical Engineering.

CHEM-001: CO2 methanation - Experimental and theoretical study.
Professor: Jan Kopyscinski
E-mail: jan.kopyscinski [at] mcgill.ca
Telephone: 514-398-4276
Website

Research Area: Reaction Kinetic, Chemical Reaction Engineering, Catalysis, Methanation, Renewable natural gas, Power to Gas process


Description:  The 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 this work, the students will work on the CO2 methanation reaction. In detail the tasks include catalysts preparation (e.g., impregnation methods, sieving) and characterization, activity test with a newly developed fixed bed reactor and modeling with Athena Visual Studio. In addition, the work include data analysis, literature review and preparation of a final report and poster presentation. The students will work closely together with other graduate students from the laboratory.

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

Deliverables:  Bi-Weekly reports, final report and and SURE poster presentation.

Number of positions: 2
Academic Level: Year 3

CHEM-002: Oilsands Pickering Emulsions
Professor: Reghan Hill
E-mail:reghan.hill [at] mcgill.ca
Telephone:514-668-9134
Website

Research Area:Nanoscience


Description:  Fundamental studies of nanoparticle-stabilized emulsions with application to Canadian oil-sands desalting operations. Cryo-electron microscopy, interfacial energy measurements, and electrokinetic-sonic-amplitude measurements.

Tasks:The assistant learn one or more of the following techniques: cryo-electron microscopy, interfacial energy measurement, electrokinetic-sonic-amplitude measurement. They will work under the direct supervision of an experienced graduate student, and will report to the PI in an effort to uncover the fundamental mechanism by which oil and water emulsions in Canadian oilsands desalting operations are stabilized by nanoparticulates.

Deliverables:  1) A detailed report summarizing the data and its interpretation on the foregoing laboratory experimental studies. The assistant must be collaborative, detail orientated, have a professional work ethic with excellent organization and communication skills, and posses a strong command of the English language.

Number of positions: 1
Academic Level: Year 3

CHEM-003: Block copolymers via controlled radical polymerization derived from renewably sourced monomers
Professor: Milan Maric
E-mail:milan.maric [at] mcgill.ca
Telephone:514-398-4272
Website

Research Area:Polymers


Description:  Controlled radical polymerization has allowed the development of new polymeric materials with the control of microstructure and chain length only previously accessible by ionic polymerization or other “living” techniques. Controlled radical polymerization techniques such as nitroxide mediated polymerization (NMP), atom transfer radical polymerization (ATRP) and reversible addition/fragmentation transfer polymerization (RAFT) do not require the stringent purification of monomers, solvents and protection of functional groups required by ionic polymerization. Further, controlled radical polymerization methods can be done in aqueous media and can combine different polymer sequences, which may not be possible using ionic polymerization. Consequently, such controlled or “pseudo-living” radical polymerizations have become increasingly popular for the production of novel polymeric materials for controlled release, separations applications, nano-wires nano-bushings and electronic materials. Block copolymers are prominently featured in such materials, particularly for their ability to self-assemble at the nm scale. The use of block copolymers, via directed self-assembly, to form patterns at nm-scale is seen as a new method to overtake conventional photolithographic approaches for microelectronics. We will examine specifically the formation of block copolymers using monomers that are renewably sourced such as itaconic acid derivatives, myrcene and others for thermoplastic elastomers, coating materials and thin films for microelectronics.

Tasks:The students will be responsible for the following:1) polymerization of renewably-sourced monomers using nitroxide mediated polymerization (one student will focus on itaconates, the other on myrcene)2) characterization of homo and block copolymer composition and microstructure 3) processing of block copolymers into desired application (rheology for thermoplastic elastomers; films for coatings - scratch testing)

Deliverables:  1) students will present findings regularly at group meetings 2) final oral report 3) final written report

Number of positions: 2
Academic Level: Year 2

CHEM-004: Thermal plasma generation and testing of graphene nanomaterials for platinum replacement in PEM fuel cells.
Professor: Jean-Luc Meunier
E-mail:jean-luc.meunier [at] mcgill.ca
Telephone:514-398-8331

Research Area:Energy (Fuel Cells): Plasma-based generation of non-noble metal catalysts


Description:  Inductively coupled thermal plasmas (ICP-TP) are used to nucleate graphene nanoflakes (GNF) on which chemical functionalizations of N, O, and Fe are added. These nanostructures act as catalyst materials for the oxygen reduction reaction (ORR) in polymer electrolyte membrane fuel cells (PEM-FC). The project involves the generation of the f-GNF following the protocols already established, and testing the performance of a series of f-GNF on our fuel cell test bench.

Tasks:-Following a formation on the ICP-TP system, running the synthesis reactor for the generation of specific f-GNF nanomaterials -Assembling the f-GNF catalyst into a PEM-FC stack -Running test protocols on the PEM Fuel Cell to evaluate the performance of the catalyst.

Deliverables:  -Demonstrate the technical knowledge and ability to run safely the ICP-TP reactor -Generate f-GNF catatalyst materials -Fuel Cell Performance evaluations of specific f-GNF materials having various amounts of atomic Fe"

Number of positions: 1
Academic Level: Year 3

CHEM-005: Study of carbon nanofibers (CNF) growth on Ni-foam and Ni-sheet structures
Professor: Jean-Luc Meunier
E-mail:jean-luc.meunier [at] mcgill.ca
Telephone:514-398-8331

Research Area:Energy (Supercapacitors) and nanomaterials


Description:  Nickel foams are used to enhance the active surface area of electrodes in supercapacitor applications, these structures being in the micrometer size range. We developed a method to grow carbon nanofibers (CNF, diameters around 50 nm) on these foams to further enhance the active area and minimize contact electrical resistances. The project is based on specific studies of CNF and possibly carbon nanotube (CNT) growth on flat Ni-foils of comparable thickness to the Ni-foam internal membranes, with an objective to better understand the driving mechanisms controlling the growth and fiber/tube diameters.

Tasks:-Apply the CNF growth protocol to Ni-foils having various pre-treatments (chemical etching and/or mechanical) -Analyse the level of CNF or CNT growth using various techniques such as microscopy, mass gain, possibly micro-Raman and TGA. -Evaluate the volumetric changes of the sample under varous carbon loading conditions

Deliverables: -Verification if CNF can be obtained on the Ni-foil under similar conditions as with Ni-foam -Etching, temperature, and mechanical strain hardening conditions that correlate with CNF or CNT growth on Ni-foils

Number of positions: 1
Academic Level: Year 2

CHEM-006: Baseline studies for environmental exposure and pre-treatment conditions.
Professor: Viviane Yargeau
E-mail:viviane.yargeau [at] mcgill.ca
Telephone:514-398-2273

Research Area:Chemical and environmental engineering


Description:  Baselines studies are currently required for two recently funded projects. 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 impacts on aquatic organism in receiving waters. Pilot studies will be conducted at two remote sites and baseline studies will be conducted in summer 2017 to characterize the current efficiency of the lagoon. The role of the research group in the second project is to assess the presence in food, water and breast milk of emerging replacement chemicals (organophosphate flame retardants, alternate plasticizers, and BPA analogues) to determine the extent to which humans are exposed, especially during critical windows of development. In 2017, sampling campaign will be conducted to optimize the experimental methods and determine expected levels in various matrices. 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 perform a literature review on data already reported in literature on one of these two topics, then will be trained on the various sample preparation and analysis methods relevant to the project, which will later be applied to the samples collected. The student will work in close collaboration with graduate students to develop an experimental plan for the summer. The student will also participate in weekly research meetings and on a regular exchange with other members of the group, including our industrial partner.

Deliverables: A report summarizing the results of the assessment of the wastewater quality in the unmodified lagoon or of the exposure to target contaminants through various sources of water. Presentation of the results at the end of the summer.

Number of positions: 3
Academic Level: Year 2

CHEM-007: Microengineered smart materials for tissue engineering
Professor: Christopher Moraes
E-mail: chris.moraes [at] mcgill.ca
Telephone: 514-398-4278
Website

Research Area: Biomedical, Chemical Engineering


Description:  Engineering biological tissues, either for replacement in humans or to develop controlled study platforms in the lab requires careful positioning of cells within a three-dimensional hydrogel matrix. Scaling these approaches up to allow positioning of individual cells at the tissue level is extremely challenging, and of vital importance in both understanding diseases and developing solutions. Smart materials respond to applied stimuli, and can be microfabricated to create a broad range of shapes on demand. Although these materials have been studied for decades, the possibility of using them to engineer better tissues has not yet been explored. In this project, the student will investigate various methods of processing smart materials on the micro-scale, and use the resulting ‘smart scaffolds’ to engineer a contractile tissue with spatial control over individual cells. These precisely-designed tissues will be used immediately to study how disease progress through tissue remodeling, but more generally, this project will explore and develop new tools to engineer artificial tissues and organs.

Tasks:  The student will gain experience in materials processing, characterization, cell culture, and microscopy; and will require the student to work closely with materials scientists, engineers and biologists.

Deliverables:  The student will design, characterize and test a novel tissue microfabrication technique capable of scaled-up production of precision-engineered biological tissues.

Number of positions: 2
Academic Level: Year 2

CHEM-008: Engineered microscale bioreactors for organ-on-a-chip technologies
Professor: Christopher Moraes
E-mail: chris.moraes [at] mcgill.ca
Telephone: 514-398-4278
Website

Research Area: Biomedical, Chemical Engineering


Description:  Fibrosis of the lungs currently affects 1 in every 2500 people, and causes stiffening of the tissue, making it difficult to breathe. The causes for this ultimately fatal disease remain unknown, and although several treatment options are now being developed to slow down disease progression, the only cure is a complete lung transplant. Developing therapies is complicated by the fact that the mechanical act of breathing itself may protect us from the disease, by influencing activity at the cellular level. Hence, identifying new therapies is challenging, when culturing cells in standard flat, plastic and mechanically static dishes. To address this challenge, this project aims to develop a microengineered bioreactor capable of applying dynamic breathing patterns of stress to high-throughput engineered human lung cultures. These bioreactors will ultimately be used to identify high-value therapeutic targets for further study and development.

Tasks:  AutoCAD, 3D printing, cell culture, immunostaining, microscopy.

Deliverables:  The student will design, build and test a programmable mechanically-dynamic cell culture bioreactor, able to accept disposable microfluidic cell culture ‘cartridges’ containing engineered human lung tissues.

Number of positions: 2
Academic Level: Year 2

CHEM-009: Investigating the environmental impacts of engineered nanoparticles in model groundwaters
Professor: Nathalie Tufenkji
E-mail: nathalie.tufenkji [at] mcgill.ca
Telephone: 514-398-2999
Website

Research Area: Environmental nanotechnology


Description:  Engineered nanoparticles (ENPs) are being increasingly incorporated into commercial products. The primary driver for their use is related to the special properties of ENPs that set them apart from their bulk counterparts, such as increased catalytic, optical, magnetic or electronic capacity. These same properties that enhance the ENPs may lead to unintended consequences should ENPs be released into the environment. Given this, it’s important to examine the fate and transport of ENPs in environmentally relevant scenarios. Much of the research on environmental impacts of ENPs has been performed with pristine ENPs and represents ideal conditions. The incorporation of ENPs into commercial products however will alter these pristine nanoparticles through processes such as functionalization of the surface or embedding ENPs into polymers or other matrices. In most cases, it remains unclear how these processes will impact the ENP properties as well as their fate and transport. The objective of this project is to investigate commercially relevant ENPs to understand how their incorporation into products may change their physicochemical properties and influence their stability in aqueous systems and their transport in porous media representative of groundwater environments.

Tasks:  The student will be trained in a range of processing and analytical/laboratory techniques that will include, for example: ENP dispersion and stabilization, determination of aggregate size via dynamic light scattering (DLS), characterization of ENP surface charge via electrophoretic mobility, and assessment of ENP mobility via laboratory 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.

Deliverables:  A written report containing all relevant methods and results, as well as a brief literature review will be submitted. Additionally, the student will give a brief presentation to the lab group summarizing their work at the conclusion of the project.

Number of positions: 1
Academic Level: No Preference

CHEM-010: Designing self-assembled 3D nanostructures for water treatment
Professor: Nathalie Tufenkji
E-mail: nathalie.tufenkji [at] mcgill.ca
Telephone: 514-398-2999
Website

Research Area: Environmental nanotechnology


Description:  2D nanomaterials such as graphene oxide (GO) are gaining increased attention due to their superior specific surface area, as well as the ability to self-assemble into 3D structures such as layered paper-like materials and sponges due to their unique geometry. The rational assembly of nanosheets into 3D structures not only boosts their mechanical properties and durability, but also opens the door to an entire host of applications which would be unattainable using individual nanosheets. Recently, it has been shown that 3D nanostructures such as GO sponges can be used for advanced water and wastewater treatment; however, sponges solely comprised of GO do not possess the required chemical functionalities to tackle real-life situations due to the complex nature and ever increasing variety of industrial and domestic contaminants. The main objective of this project is to process nanocomposite sponges with superior mechanical properties and a wide variety of chemical functionalities for efficient and fast adsorption of classical and emerging water contaminants. A special emphasis will be put on functionalizing the sponges using various chemical and physical methods to tailor their surface for adsorption of contaminants of concern.

Tasks:  The student will be trained in a range of processing and analytical/laboratory techniques that will include: synthesis of graphene sponges, mechanical testing of synthesized sponges, testing of adsorption potential for a range of water contaminants. After receiving the required training in the lab (first month), the student will start working more independently in processing of NPs and nanostructures and studying their capacity to adsorb water contaminants. The student will be introduced to a range of new areas including materials chemistry and environmental nanotechnology. There will be opportunities to continue this research as a graduate project in the future.

Deliverables:  A written report containing all relevant methods and results, as well as a brief literature review will be submitted. The student will also be asked to present his/her work to the lab group or in a departmental research conference.

Number of positions: 2
Academic Level: No Preference

CHEM-011: Green synthesis of gold nanoparticles using cellulose nanocrystals
Professor: Nathalie Tufenkji
E-mail: nathalie.tufenkji [at] mcgill.ca
Telephone: 514-398-2999
Website

Research Area: Nanomaterials


Description:  Nanomaterials are currently being used or developed for many applications such as consumer goods, in drug delivery, and in building materials. The controlled synthesis of nanomaterials is important to make use of the interesting properties which makes them very attractive to the industry. It is challenging to scale current processes of synthesis while maintaining control of the properties of the particles. Additionally, there is a need to synthesize particles with specific properties such as controlled shape and size in an environmentally friendly way. These nanoscale properties have high impact on the characteristics exhibited at the macroscale. This project will explore the possibility of controlling the size, shape and crystallinity of gold nanoparticles, using a green chemistry approach (low energy and non-toxic starting materials). Furthermore, toxicity will be evaluated and compared with that of commercial products. The results of this work will be of great interest for biomedical and commercial applications.

Tasks:  1. The student will become familiar with the literature related to gold nanoparticle synthesis using green methods. 2. The student will be trained in a range of areas that include: nanoparticle synthesis, nanoparticle characterization techniques (e.g. Dynamic Light Scattering: for measuring hydrodynamic radius of the particles, UV-VIS spectroscopy: for defining the plasmon bands and electromagnetic absorption of the particles, Transmission Electron Microscopy: for imaging at the nanoscale), basic microbiology and general laboratory practices. The student will be given ample guidance in improving their written and oral presentation skills, which will be valuable for any future study/work environment. 3. After receiving the required initial training/skills in the lab (first month), the student will start working independently under the guidance of a PhD candidate. This project is part of a study on synthesis of nanomaterials using cellulose nanocrystals. The student will be introduced to a range of new research areas in nanotechnology. There will be opportunities to continue this research as a graduate research project in the future

Deliverables:  A final written report containing all relevant methods, brief literature review and results, as well as weekly progress reports will be submitted. The student will be required to give a short presentation of the work at the end of the summer.

Number of positions: 2
Academic Level: No Preference

CHEM-012: Rheological investigations of phase change systems
Professor: Phillip Servio
E-mail: phillip.servio [at] mcgill.ca
Telephone:514-398-1026
Website

Research Area: Rheology


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.

Deliverables:  Collection and analysis of experimental data for submission to his or her supervisor. The student may contribute to the writing of portions of a manuscript that may result in a publication.

Number of positions: 1
Academic Level: Year 2

CHEM-013: Nucleation Phenomena of Gas Hydrate-Forming Systems
Professor: Phillip Servio
E-mail: phillip.servio [at] mcgill.ca
Telephone:514-398-1026
Website

Research Area: Energy


Description:  Clathrate hydrates are ice-like solids composed of a guest gas encaged within a lattice of water molecules. Also known as gas hydrates, these crystalline solids have long been a source of trouble for the oil and gas industry, particularly in offshore projects. When light hydrocarbons, such as methane, ethane and propane, are contacted with water under high pressures and low temperatures, gas hydrates form. These solids form in blowout preventers, choke-lines, kill-lines and gas transmission lines. Gas hydrates that form in gas pipelines may accumulate and plug the pipe entirely, resulting in severe environmental, infrastructural, and economical consequences, in addition to jeopardizing the safety of working personnel. In order to better predict and understand hydrate formation, its crystallization process must be studied. Nucleation, which is the formation of microscopic clusters of hydrates that precedes the crystal growth event, is an intrinsically random event that has not been studied systematically. However, since nucleation is often the rate-limiting step in hydrate crystallization, it is imperative that engineers gain a better and more complete understanding of this phenomenon.

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 gas hydrate nucleation, both at atmospheric and high pressures. The time taken for a sample to nucleate (induction time) will be detected via thermal imaging. The effect of various factors, such as degree of sub-cooling and inhibitor addition, that influence the induction time of a sample will be investigated. He/she will work closely with a graduate student on this project but must also be able to work independently and diligently.

Deliverables:  Collection and analysis of experimental data for submission to his or her supervisor. The student may contribute to the writing of portions of a manuscript that may result in a publication.

Number of positions: 1
Academic Level: Year 2

CHEM-014: Competitive Protein Adhesion to Functional Plasma Polymer Films
Professor: Pierre-Luc Girard-Lauriault
E-mail: pierre-luc.girard-lauriault [at] mcgill.ca
Telephone:514-398-4006
Website

Research Area: Plasma Science


Description:  Synthetic Polymers are used in several technological applications due to their many desirable properties: low cost, good mechanical properties, resistance to corrosion and durability. However, their surfaces are typically hydrophobic which limits their wettability and biocompatibility. This issue can be addressed using surface engineering: selectively tailoring the surface properties of materials without affecting the desirable bulk properties. 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. A critical parameter influencing the performance of plasma deposited functional layers, generally know as plasma polymers, is the adhesion of proteins contained in a biological media to their surfaces. The adhesion is a competitive process between the different proteins present. The project will first involve the preparation of plasma deposited organic coatings on gold sensors and their surface chemical characterization. The project will then involve the use of surface plasmon resonance to characterize the adhesion of protein mixtures to surfaces. 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 - Evaluation of protein adhesion

Deliverables:  Plasma deposited set of samples and the characterization of protein adhesion.

Number of positions: 1
Academic Level: No Preference

CHEM-015: Engineering vascular biomaterials that promote regeneration
Professor: Corinne Hoesli
E-mail: corinne.hoesli [at] mcgill.ca
Telephone:514-398-4275
Website

Research Area: Bioengineering


Description:  Around 80% of coronary artery disease patients are treated by the implantation of a vascular scaffold in the diseased area. The lack of adequate endothelial coverage on the surface of vascular scaffolds leads to re-narrowing of the artery and can promote thrombus formation in the implant. Modifying the surface of such scaffolds with extracellular matrix (ECM)-derived peptides can potentially enhance the endothelialization of the scaffold by recruiting endothelial progenitor cells (EPCs) to the surface. The objective of this project is to assess the ability of surface conjugated ECM-derived peptides to promote the re-endothelialization of vascular substitutes. The short term goal of the project is to compare the ability of different poly-styrene conjugated ECM-derived peptides in promoting the adhesion of adult peripheral blood EPC-derived cells under static conditions. The peptide-modified surfaces will be prepared by a two step wet chemistry technique using a linker. Cells derived from adult peripheral blood will be seeded on the different surfaces to assess EPC adhesion. 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: Preparation of peptide-modified culture surfaces, mammalian cell culture, immunocytochemistry, fluorescence microscopy, image analysis, experimental design, data analysis, data presentation at group meetings, collaboration with research groups in chemical engineering and medicine at McGill, Université Laval, and the Montreal Heart Institute

Deliverables:  Lab meeting presentation and final report

Number of positions: 1
Academic Level: No Preference

CHEM-016: Pancreatic cell encapsulation using microchannel emulsification to treat diabetes
Professor: Corinne Hoesli
E-mail: corinne.hoesli [at] mcgill.ca
Telephone:514-398-4275
Website

Research Area: Bioengineering


Description:  Islet transplantation has emerged as a potential long-term treatment for type 1 diabetes. One of the main limitations to this approach is the need for chronic immunosuppression. To overcome this limitation, islets can be encapsulated in microbeads that create a barrier between the graft and the host immune system. Our laboratory has developed a highly scalable and robust cell encapsulation process that is based on stirred emulsification and internal gelation to create alginate beads. However, the beads obtained via the stirred process have a broad bead size distribution. Microchannel emulsification has been used in other chemical engineering fields to produce emulsions with narrow size distribution. Our laboratory has demonstrated proof-of-concept of alginate bead production using microchannel emulsification. The objective of this project is to further optimize this process and to implement a commercially-available membrane emulsification cell to generate the beads in a batch process. The results of this project could significantly impact diabetes research. The process could also be applied to other encapsulated products in the food and drug industries.

Tasks: Mammalian cell culture, cell encapsulation, cell viability assays, method development, mechanical testing, experimental planning, data analysis, coordination of communication with collaborators, lab meeting presentations

Deliverables:  Lab meeting presentation and final report

Number of positions: 1
Academic Level: No Preference

Follow us