Polyimide Organic Solvent Nanofiltration Membranes-Formation and Function

This thesis offers a comprehensive study that analyses the relationship between polyimide (PI) organic solvent nanofiltration (OSN) membrane formation parameters, membrane structure, and membrane functional performance. The dissertation starts by addressing the structure-related problem of macrovoid formation, which arises when more open membranes are prepared. Incorporation of TiO2 nanofillers into the membrane matrix results in macrovoid-free, organic/inorganic PI/TiO2 mixed matrix membranes without compromising rejection. Subsequently, a detailed analysis of the membrane formation process, considering the dope solution composition, evaporation step, and structural properties of polyimides, was conducted. The effect of the choice of polymer/solvent/co-solvent/non-solvent was found to be very profound and qualitatively predictable through introduction of a complex solubility parameter. Increasing value of complex solubility parameter can predict higher rejections. The study of the evaporation in PI OSN membrane formation has shown that this optional step is undesirable, as its presence results in unaltered rejection and significantly lower flux. Nevertheless, the presence of a co-solvent, regardless of whether it is volatile or not, was found to be required as it promotes formation of a dense membrane top layer. We have also studied sensitivity of PI OSN membranes to small perturbations in polymer characteristics, such as: molecular weight, alternating diisocyanates to form the PI chain, and copolymerisation method (block vs random). Finally, we proposed a less hazardous route for the PI OSN membrane formation process, which would reduce environmental impact without compromising the separation performance of the existing membranes

Radiative Effects in the Processes of Hadron Electroproduction

An approach to calculate radiative corrections to unpolarized cross section of semi-inclusive electroproduction is developed. An explicit formulae for the lowest order QED radiative correction are presented. Detailed numerical analysis is performed for the kinematics of experiments at the fixed targets.Comment: 7 pages, 4 figure

Uncountably many quasi-isometry classes of groups of type FPFP

Previously one of the authors constructed uncountable families of groups of type $FP$ and of $n$-dimensional Poincar\'e duality groups for each $n\geq 4$. We strengthen these results by showing that these groups comprise uncountably many quasi-isometry classes. We deduce that for each $n\geq 4$ there are uncountably many quasi-isometry classes of acyclic $n$-manifolds admitting free cocompact properly discontinuous discrete group actions.Comment: Version 2: minor corrections made, theorems now numbered by sectio

The Role of Knowledge and Perceived Level of Self-Efficacy on Junior Division Teachers’ Implementation of Physical Literacy in Ontario

The Ontario, Health and Physical Education, Grades 1-8 (HPE) curriculum policy document identifies physical literacy as a key component of the overall vision and goal of the subject. Teachers play a primary role with the implementation of the HPE curriculum policy document and as a result can significantly influence a student’s overall physical literacy journey. The release of the HPE curriculum policy document in 2010 provided a definition of physical literacy for elementary teachers in Ontario, which has remained consistent since that time. However, there is limited data on how school boards, schools, and teachers have implemented physical literacy within the context of the Ontario HPE curriculum. This research explored the role that junior division (Grades 4-6) teachers’ knowledge of physical literacy and perceived levels of self-efficacy for teaching HPE has on their implementation of physical literacy within their classroom. Using a mixed methods design, this study examined how junior division teachers’ (n = 35) perceived levels of self-efficacy and knowledge of physical literacy influenced their ability to implement physical literacy within the classroom program. Participants completed an online survey and eight individuals participated in individual interviews for this study. Two main findings related to implementation of physical literacy were that: (a) teachers indicated a need for resources/supports and accessed them from several sources; and, (b) teachers reported several barriers for both implementation of HPE along with others that were more specifically related to COVID-19 protocols. These results have implications for how teachers in schools can be supported with the implementation of physical literacy in order to provide quality learning opportunities that contribute to a student’s physical literacy journey