University of Saskatchewan X-ray technology, wetlands research get NSERC boost

Creed, executive director and professor at the U of S School of Environment and Sustainability, has been awarded an NSERC Strategic Partnership Grant of $827,000 to study the loss of wetlands in prairie agricultural areas and the impact it has on the sequestration of the carbon, nitrogen and phosphorus nutrients that promote algal growth in downstream lakes.

Creed’s group includes soil scientists Tim Moore from McGill University and David Lobb from the University of Manitoba, isotopic geochemist Sherry Schiff from the University of Waterloo, and algal bloom specialist Charles Trick from Western University.

“What we want to know is by removing these wetlands, have we compromised the ability of landscapes to process the nutrients that are now flowing downstream to places like Lake Winnipeg, contributing to the algal blooms which are a serious problem for people living there?” said Creed.

She notes that neurotoxins produced by some algal blooms have been linked to neurological disorders such as Alzheimer’s and Parkinson’s disease, while hepatoxins in algae cause liver disease.

“Ultimately we can reduce risk to human health and well-being by putting wetlands back on the landscape,” she said.

Creed said the NSERC award, announced today by Minister of Science and Sport Kirsty Duncan, will enable the group to unify some smaller projects in Alberta, Saskatchewan, Manitoba and Ontario, and provide a broader geographic context that will help connect wetlands to the drainage of water and nutrients, and to the risk of floods, drought and eutrophication (excessive nutrients in water bodies).

Understanding the role of wetlands will lead to scientific evidence that supports public policies to restore these areas, and provide farmers with market-based incentives (such as carbon credits) to retain or construct wetlands on their property. 

“Such action is especially important to Saskatchewan, which lags in wetlands protection and restoration policies,” Creed said.

Kelly, associate professor in chemistry and Canada Research Chair in Photovoltaics in the College of Arts and Science, was awarded $412,500 for developing new technology aimed at transforming X-ray imaging currently used in breast cancer screening––a paradigm shift in technology that will provide Canadian manufacturers an advantage over global competitors.

Kelly is an expert in the use of lead halide perovskites (a material with a crystal structure that has a particular arrangement of atoms) to develop efficient solar cells. 

His co-applicant on the project, Safa Kasap, distinguished professor of electrical and computer engineering in the U of S College of Engineering, developed the photoconductor currently used in flat panel X-ray image detectors for mammography. Their industry partner is Analogic Canada Corporation, a leading detector manufacturer.        

Lead perovskites are very good electrical semiconductors, with the added benefit of having a high stopping power and sensitivity for X-rays, Kelly said. The goal is to convert the X-rays to electricity and generate images.

The current technology requires a thick coating of amorphous selenium at the heart of the detectors. While these detectors provide good quality, high resolution images, the process used to vaporize the selenium is highly expensive because of the energy required, and is time consuming and laborious.

The goal is to replace the selenium in the detectors with perovskite. Unlike selenium, lead perovskite can be used as a paint or ink that can be applied in a thin layer on surfaces to absorb X-rays, Kelly said, and his group has been developing ink formulations for the perovskites and developing coating technology.

Kasap’s group has expertise in measurement and electrical testing of the devices after they are made. Once the teams have produced a prototype detector, Analogic will help them figure out if it’s good in terms of resolution and detection limits.

“This is a great example of a Canadian company that has a distinct technological advantage over competitors because of the technology with amorphous selenium that was developed by Safa. We’re hoping to extend that advantage with the work we’re doing on perovskites,” said Kelly.

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