麻豆AV

Description

The design of I-shape steel sections as tension, bending & shear, or tension + bending & shear load carrying members often requires that at member ends or splices a flange (and web) bolted connection be used. The flange(s) of the I-shape will be subjected to tension stress (direct or bending induced), and as such must be designed accounting for the associated net section failure modes including block shear failure. Yet, confirmation of this failure mode in I-shape sections has not been carried out through testing or numerical analyses on representative beam members. As such, questions arise. Do the proportions of typical I-shape rolled beams and tension members lead to changes in the formation of the block shear failure mode compared to the WT shapes that have been tested? Does a bending induced tension (stress gradient resulting in possible stress redistribution) result in a different block shear failure mode compared with the application of direct (uniform) tension to the cross-section? In addition to the block shear calculations as per CSA S16, engineers must also consider the bending resistance reductions for members with holes in the tension flange, under the general rules for the proportioning of beams and girders. These provisions date back to the work of Lilly & Carpenter in 1940, who investigated the effective moment of inertia of a built-up riveted plate girder, which bears no resemblance to the typical steel members and connections used in construction today.

Tasks

The research project comprises a laboratory study on the block-shear failure mode for I-shape members, specifically at the location of moment connections. These connections can be either at the beam to column joint, or at the splice of a beam. The role of the SURE student is to provide support for the graduate students responsible for the research project. The SURE student will prepare the laboratory for testing including installation of test apparati. In addition, she / he will assemble and instrument test specimens, install test specimens into the loading frame, set up instrumentation for measurements, and run the tests. Having an ASP Health and Safety on Construction Sites course certificate is advised.

听

Number of positions

2

Academic Level

Year 3

Description

Reinforced concrete bridge columns will be constructed in the structures laboratory. These test specimens will be instrumented with strain gauges to determine the stresses in the reinforcing bars. The specimens will be loaded with axial load and subjected to reversed cyclic loading to simulate earthquake loading effects. This experimental program will enable an assessment of the shear resistance of these critical structural members. Factors such as the spacing and amount of transverse reinforcement on the shear response will be investigated.

Tasks

- construction of reinforced concrete columns - instrumenting reinforcing bars - casting of concrete - simulated earthquake testing

听

Number of positions

1

Academic Level

Year 2

Description

Methane is a potent greenhouse gas and reducing its emissions can substantially combat global warming in the short term. Recent measurements have shown that abandoned oil and gas wells are sources of methane to the atmosphere. The project involves preparing one or more field trip(s) to oil and gas-producing regions and analyzing the results in the laboratory. Various methods including flux chambers and mobile instruments will be used to measure methane flow rates and other geochemical parameters. The findings from this study will provide quantitative data for evaluating and designing mitigation solutions for the millions of abandoned oil and gas wells around the world.

Tasks

Prepare for one or more field sampling trip(s), conduct field sampling, and analyze results.

听

Number of positions

1

Academic Level

No preference

Description

Deep groundwater aquifers may be a valuable resource, especially during severe droughts and in arid regions, in decades and centuries to come. It is now increasingly common to find groundwater wells drilled to several kilometer depths in California, Texas, the Middle East, and other arid regions. Therefore, we ask: which regions in the world could benefit most from analysis of their deep groundwater aquifers and what are the characteristics of these aquifers? The project involves developing and analyzing groundwater databases and for selected basins, applying numerical/analytical models. This project complements on-going research on characterizing and analyzing deep groundwater aquifers to manage and protect these resources.

Tasks

Database compilation and analysis, including using geospatial analysis tools (e.g., ArcGIS) and developing data processing tools (e.g., Matlab and Python scripts).

听

Number of positions

1

Academic Level

No preference

Description

Much of southern Ontario is covered in surficial deposits of tills and the St Lawrence Valley in marine clays. These are cohesive sediments, having a wide range of relatively low critical shear stresses, resulting in design difficulties. The aim is to better describe the spatial variation and range of soil properties of this two materials. The surficial geology of southern Ontario and the St. Lawrence valley will be reviewed to identify the deposits of till and marine clay. Rivers incised into these deposits will be identified and a field survey undertaken to observe erosion and obtain representative soil samples. Standard soil analysis will be made of these samples and a report written to summarize the work.

Tasks

Field survey of glacial deposits and soil analysis of representative soil samples collected.

听

Number of positions

1

Academic Level

Year 3

Description

Low dissolved oxygen levels downstream of hydropower stations results in damage to the riverine ecosystem. An experimental rig will be designed to investigate retrofit options to increase DO levels downstream of the hydraulic turbines. The data acquisition system will also be designed and, if time allows, implemented.

Tasks

Assistant to postdoctoral student in the design of the experimental rig based on previous work and literature review.

听

Number of positions

1

Academic Level

Year 2

Description

Eighty percent of drinking water distribution systems within both institutional and residential buildings are copper pipes with fittings and solder that contains lead. These are cytotoxic to bacterial contamination but corrosion may result in increased levels in the drinking water. A field survey will be undertaken to determine the range of metal concentrations in drinking water at the point of consumption and correlate to water quality parameters and infrastructure parameters.

Tasks

Collaborate with a doctoral student in the design and implementation of the field survey and in the sample analysis.

听

Number of positions

1

Academic Level

Year 2

Description

Perfluorooctane sulfonic acid (PFOS) and perfluorooctane carboxylic acid (PFOA) are newly recognized significant sources of persistent organic pollutants (POPs) found worldwide. They are bioaccumulative, developmentally toxic and likely carcinogenic. US EPA has proposed Provisional Health Advisory values of 70 ng/L for PFOA and PFOS in drinking water. The project aims to develop low-cost remediation technologies to remove or stabilize in situ PFOS, PFOA and related pollutants in contaminated groundwater and soil systems. Two technologies will be tested. Modified clays that resistant fouling by natural colloidal materials will be evaluated for soil remediation and water treatment. The ability of the adsorbents in reducing bioaccumulation potential of the pollutants bound in soil will be evaluated using earthworms. Microbubble technology will be evaluated for the capacity to efficiently concentrate such pollutants at a very low energy cost.

Tasks

The students will be performing the research under the supervision of Prof. Liu and with the support of two graduate students. The students will start with assisting the graduate students with laboratory experiments, and then transition to perform certain experiments independently. They are expected to perform data analysis and may participate in publication preparation.

听

Number of positions

2

Academic Level

No preference

Description

Proposals for the deep geologic disposal of heat emitting nuclear fuel waste are being investigated by the Canadian agencies responsible for developing the research background for examining the thermo-hydro-mechanical processes in a Deep Ground Repository (DGR) setting. In Canada, attention is now being re-focused on the possible siting of a DGR in the Canadian Shield, which consists of granitic rock. The temperatures to which the rock can be subjected to bu the heat-emitting stored wastes can range from 100 Deg C to 150 Deg C. In this research project, the alterations in the permeability characteristics of the Lac du Bonnet granite due to heating will be experimentally investigated. Both dry and saturated samples of the Lac du Bonnet granite will be subjected to heating to assess the role of thermally-induced pore fluid pressures in the initiation of permeability enhancement

Tasks

The student will develop the samples and perform the heating experiments and permeability experiments

Number of positions

1

Academic Level

Year 2

Description

Anaerobic digestion of waste activated sludge (WAS) is one of the most common processes used for biosolids reduction because it can convert about 50% of organic matter present in sewage sludge into valuable methane biogas. One of the important considerations in anaerobic digester design is the hydrolysis step because of anaerobes, especially methanogens, grow slowly. Typical digesters are operated at 35脗掳C to allow the fast enough hydrolysis; however, heating the waste activated sludge (WAS) from 5-20脗掳C (wastewater temperature) to 35脗掳C is a considerable energy expense. We hypothesized that ozonation can enhance the disintegration/hydrolysis rate making it feasible to operate at low mesophilic temperature (20脗掳C) instead of the conventional anaerobic digester operated at 35脗掳C while maintaining similar SRTs. This will allow the operation of the digester without heating and increase the energy produced in the form of methane. The project, for the most part, will take place in the laboratory. Three laboratory-scale anaerobic digesters will be continuously operated for the 12 weeks: One single reactor ozonated at 20脗掳C and pH 7 as control and two staged anaerobic digestions with two reactors in series; the fermentation reactor will be operated at two different pH 7 and 10 with a SRT 2-4 days. For the digesters, the SRT will be maintained at 15 days. During the internship time, several operation parameters will be tested including: TSS, COD, the temperature of operation, the dose of ozone, and the source of solids to expose to ozone (partially digested solids). The variations in operation will aim at optimizing the operation to provide the greatest energy yield from the digester.

Tasks

Perform the daily maintenance and sampling of the laboratory-scale reactors. Perform laboratory analyses to determine physico-chemical characteristics of samples. Contribute to computer data entry and trend analyses.

Number of positions

1

Academic Level

Year 2

Description

Engineered nanoparticles (ENPs), which have at least one dimension in the range of 1-100 nm, are used in the manufacture of industrial and consumer products, to enable or enhance specific functions towards delivery of high performance products. Many ENP-containing products are directly exposed to the environment. As a result, ENPs may be released to the environment, particularly to aquatic ecosystems. Recently, some estimates have been provided from model predictions based on approximate worldwide production volumes, and materials flow analyses from the products to different environmental compartments. These studies suggest that levels of ENPs in the environment are close to levels that induce toxicity in aquatic organisms, and with increased production of ENPs in future years, are likely to cause adverse impacts to aquatic ecosystem health. In this study we will assess the release of a number of commonly used ENPs in paint when these products are exposed to atmospheric precipitation or percolating water. Pristine ENPs used in the manufacture of the products ENPs released from the products to water will be characterized for size, concentration, aggregation behavior, mobility, biological uptake and toxicity to aquatic organisms will be evaluated with a suite of cutting edge techniques. The results will provide a critical assessment of the question of how the environmental risks of ENPs released from products differ from pristine ENPs. The results will be critical for informing policies on the implementation of safe nanotechnology.

Tasks

1. Develop sample preparation methods and analytical methods for characterizing metal nanoparticles released from paints 2. Assess the environmental fate of nanoparticles released from paint into surfacewaters

Number of positions

2

Academic Level

Year 3

Description

The municipal wastewater and organic solids waste industries are undergoing a resource recovery revolution. Producing useful biomaterials from wastes promises great economic and environment benefits. Important biomaterials to produce include the bioplastic precursor polyhydroxyalkanoate (PHA), and the phosphorus (P) mineral carbonate apatite (i.e., phosphate rock) used in fertilizers. The summer project will involve the operation and chemical analysis of a new bioreactor growing infrared-using photoheterotrophic purple non-sulfur bacteria (PNSB) to synthesize PHA and concentrate P. Current techno-economic studies of PHA production suggest that mixed cultures are more economical than pure cultures fed sterilized feedstocks. Thus, our project will provide cost reduction, and end-product versatility. In collaboration with a few graduate students, the PHA and phosphorous compounds accumulated will be chemically characterized and conversion rates may also be measured.

Tasks

Perform the daily maintenance and sampling of the laboratory-scale reactors. Perform laboratory analyses to determine physico-chemical characteristics of samples. Contribute to computer data entry and trend analyses.

Number of positions

1

Academic Level

Year 2

Description

The built environment characterized by urbanization is a significant forcing function on the weather-climate system because it is a heat source, a poor storage system for water, an impediment to atmospheric motion and a source of aerosols. The most common manifestation of urban climate is the urban heat island (UHI), which is characterized by warmer surface temperatures in urban landscapes due to heat-retaining materials, lack of vegetation and excessive anthropogenic heat sources. There is an emerging interest in knowing how urban environments modify weather and climate, particularly the extreme events. This can only be achieved through high-resolution modelling, using climate models that include good representation of urban regions. Such modelling work is also important to inform adaptation of urban infrastructure in a changing climate. This research, through carefully designed sensitivity experiments using a high resolution regional climate model, will assess flood mitigation strategies for different Canadian cities. Green infrastructure practices that enhance infiltration are recommended to reduce flooding. The impacts of such infrastructure on the urban weather and climate will be quantified enabling science-informed decision making. This will be crucial in the effort to build greener, sustainable, climate resilient cities. This study will be undertaken in collaboration with engineers from Ocean, Coastal and River Engineering Research Centre (OCRE) of the National Research Council Canada (NRC), who will provide access to different data sources and guidance on green infrastructure.

Tasks

Review previous flooding events, associated mechanisms for coastal and in-land Canadian cities and mitigation strategies in place or proposed.

Number of positions

2

Academic Level

No preference

Description

Wood reinforced slag composite is a new construction material that is recently developed in Civil Engineering Materials Laboratory. The composite is made of wood wool (residues from wood industry), steel slag (by-product from steel mill) and carbon dioxide (collected from steel-refinery furnace). The composite will be used to make the slag-bond particleboard to compete with well-developed and well-marketed oriented strand board (OSB) for construction industry. In comparison to resin-bond OSB, there are several advantages. The slag-bond particleboards offer sound insulation, water and frost resistance, mold/fungus resistance, fire resistance, and do not require the addition of formaldehyde. In addition the wood reinforced slag composite is totally waste-derived, consumes no virgin materials, produces much less emission, is able to sequester carbon dioxide and offers an environment-friendly and healthy building product. This SURE project is to characterize the performance of the newly-developed composite material and conduct a cost analysis.

Tasks

Tasks: 1) To learn how to make wood reinforced slag composite for particleboard application. (Confidential agreement is necessary to carry out the project.) 2) To evaluate physical and mechanical performance: Flexural strength, compressive strength, water absorption, nailability, machinability, freeze-thaw and fire resistance 3) To perform cost analysis and life-cycle emission analysis

Number of positions

1

Academic Level

Year 3

Description

Rocks constituting geological formations are characterized by defects that are created tectonic action and other geochemical processes. The bulk transport of fluids in such geological formations can be controlled by the permeability of fractures and has important applications to several areas of environmental geomechanics with relevance to groundwater resources, contaminant transport, geologic sequestration of greenhouse gases and energy extraction. The objective of this research is to examine experimentally the surface topography of fracture surfaces and to develop models for the effective permeability characteristics of the fracture based on the statistical measures of the geometry. The experiments will involve the laser scanning of fracture surfaces in large diameter cylinders of granite from Stanstead, Quebec and the Lac du Bonnet, Manitoba. The results from the scans will be used to develop elementary parallel plate models of planar fractures. The permeability of the fractures will be estimated by initiating radial flow through the planar fractures.

Tasks

1. Perform the laser scanning experiments. 2. Develop statistical measures of the scanned surfaces. 3. Perform experiments of radial flow through fractures

Number of positions

1

Academic Level

Year 2

Description

The objective is to perform measurements, perform analyses and assist in the development of a seismic microzonation map for the Greater Montreal Area. The measurements will be performed be measuring ambient noise in the field (driver license is a requirement). Analyses performed on the records will be used to determine the fundamental period as a function of the impedance ratio of soil deposits. Analyses will be performed to correlate this information with surface geology data and develop a regional seisimic microzonation map. The information will then be processed in a geographical information system to perform seismic hazard and risk analyses.

Tasks

Measuring ambient noise in the field (driver license is a requirement). Analyses performed on the records will be used to determine the fundamental period as a function of the impedance ratio of soil deposits. Analyses will be performed to correlate this information with surface geology data and develop a regional seisimic microzonation map. The information will then be processed in a geographical information system to perform seismic hazard and risk analyses.

Number of positions

1

Academic Level

No preference

Description

Residential buildings in the Greater Montreal Area are mainly wood frames structures (97%). The project consists in documenting construction practices for this type of building over time and to make measurements to determine their dynamic properties. This information will be used to classify buildings of different types and to determine the most appropriate fragility curve to perform seismic risk analyses based on previous experimental tests and by performing some structural analyses of typical buildings.

Tasks

Documenting construction practices for this type of building over time, make measurements to determine their dynamic properties. Develop classes of buildings of different types and investigate the most appropriate fragility curve for seismic risk analyses based on previous experimental tests and some structural analyses.

Number of positions

1

Academic Level

No preference