Research

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  • A changing landscape in collection development
    A changing landscape in collection development
    Ryerson University Library has been exploring different just-in-time acquisition models that provide us with cost-effective ways to purchase monograph titles with guaranteed usage. Based on our experience with Ebrary on the PDA (Patron Driven Acquisitions) Pilot, and with YBP on the DDA (Demand Driven Acquisitions) project, this discussion will focus on the theory behind our approach, the technicalities of implementation, and implications for future collection development strategies.
    A computational study of soot formation and flame structure of coflow laminar methane/air diffusion flames under microgravity and normal gravity
    A computational study of soot formation and flame structure of coflow laminar methane/air diffusion flames under microgravity and normal gravity
    A numerical study is conducted of methane-air coflow diffusion flames at microgravity (μg) and normal gravity (lg), and comparisons are made with experimental data in the literature. The model employed uses a detailed gas phase chemical kinetic mechanism that includes PAH formation and growth, and is coupled to a sectional soot particle dynamics model. The model is able to accurately predict the trends observed experimentally with reduction of gravity without any tuning of the model for different flames. The microgravity sooting flames were found to have lower temperatures and higher volume fraction than their normal gravity counterparts. In the absence of gravity, the flame radii increase due to elimination of buoyance forces and reduction of flow velocity, which is consistent with experimental observations. Soot formation along the wings is seen to be surface growth dominated, while PAH condensation plays a more major role on centerline soot formation. Surface growth and PAH growth increase in microgravity primarily due to increases in the residence time inside the flame. The rate of increase of surface growth is more significant compared to PAH growth, which causes soot distribution to shift from the centerline of the flame to the wings in microgravity. Keywords: laminar diffusion flame,methane-air,microgravity, soot formation, numerical modelling, Veshkini, R., & Dworkin, S. B. (2017). A computational study of soot formation and flame structure of coflow laminar methane/air diffusion flames under microgravity and normal gravity. Combustion Theory and Modelling. http://dx.doi.org/10.1080/13647830.2017.1308558
    A dynamic coefficient matrix method for the free vibration of thin rectangular isotropic plates
    A dynamic coefficient matrix method for the free vibration of thin rectangular isotropic plates
    The free flexural vibration of thin rectangular plates is revisited. A new, quasi-exact solution to the governing differential equation is formed by following a unique method of decomposing the governing equation into two beam-like expressions. Using the proposed quasi-exact solution, a Dynamic Coefficient Matrix (DCM) method is formed and used to investigate the free lateral vibration of a rectangular thin plate, subjected to various boundary conditions. Exploiting a special code written on MATLAB, the flexural natural frequencies of the plate are found by sweeping the frequency domain in search of specific frequencies that yield a zero determinant. Results are validated extensively both by the limited exact results available in the open literature and by numerical studies using ANSYS and in-house conventional FEM programs using both 12- and 16-DOF plate elements. The accuracy of all methods for lateral free vibration analysis is assessed and critically examined through benchmark solutions. It is envisioned that the proposed quasi-exact solution and the DCM method will allow engineers to more conveniently investigate the vibration behaviour of two-dimensional structural components during the preliminary design stages, before a detailed design begins., Supun Jayasinghe and Seyed M. Hashemi, “A Dynamic Coefficient Matrix Method for the Free Vibration of Thin Rectangular Isotropic Plates,” Shock and Vibration, vol. 2018, Article ID 1071830, 8 pages, 2018. https://doi.org/10.1155/2018/1071830.
    A finite element formulation for bending-torsion coupled vibration analysis of delaminated beams under combined axial load and end moment
    A finite element formulation for bending-torsion coupled vibration analysis of delaminated beams under combined axial load and end moment
    Free vibration analysis of beams with single delamination undergoing bending-torsion coupling is made, using traditional finite element technique. The Galerkin weighted residual method is applied to convert the coupled differential equations of motion into to a discrete problem, where, in addition to the conventional mass and stiffness matrices, a delamination stiffness matrix, representing the extra stiffening effects at the delamination tips, is introduced. The linear eigenvalue problem resulting from the discretization along the length of the beam is solved to determine the frequencies and modes of free vibration. Both “free mode” and “constrained mode” delamination models are considered in formulation, and it is shown that the continuity (both kinematic and force) conditions at the beam span-wise locations corresponding to the extremities of the delaminated region, in particular, play a great role in “free mode” model formulation. Current trends in the literature are examined, and insight into different types of modeling techniques and constraint types are introduced. In addition, the data previously available in the literature and those obtained from a finite element-based commercial software are utilized to validate the presented modeling scheme and to verify the correctness of natural frequencies of the systems analyzed here. The paper ends with general discussions and conclusions on the presented theories and modeling approaches., Mir Tahmaseb Kashani and Seyed M. Hashemi, “A Finite Element Formulation for Bending-Torsion Coupled Vibration Analysis of Delaminated Beams under Combined Axial Load and End Moment,” Shock and Vibration, vol. 2018, Article ID 1348970, 12 pages, 2018. https://doi.org/10.1155/2018/1348970.
    A human-health risk assessment of dietary methylmercury exposure in Fort Albany First Nation
    A human-health risk assessment of dietary methylmercury exposure in Fort Albany First Nation
    In Northern First Nations communities, traditional diets are a primary pathway for essential nutrients and exposures to environmental contaminants. Due to long-range transport and industry pollution, Fort Albany First Nation is a community at risk of methylmercury exposures through fish. It’s ability to bioaccumulate, and its neurotoxic and developmental impacts, make its presence a concern. This study assessed five fish species for methylmercury from the Albany River. All species, except for Pike, demonstrated a positive relationship with mercury concentrations increasing with length. A human health risk assessment was conducted and demonstrated twice the risk of exceeding the reference dose for children ages 3 to 6 for all species, and 6 to 11 for all species, excluding Whitefish. It is recommended that vulnerable populations consuming certain species of fish reduce their intakes or encourage community trading. Furthermore, there is a need for more thorough testing for mercury along the river basin
    A hybrid method to design and optimize a battery closed-loop supply chain:  multi-objective approach
    A hybrid method to design and optimize a battery closed-loop supply chain: multi-objective approach
    There are a variety of prominent factors associated with total expected profit of a closed-loop supply chain (CLSC). In a forward flow, volatility in transportation cost, inventory cost, and forecasting the market’s demand are the most challenging issues for decision makers, while determining the rate of returned products and efficiency in recycling the returned products are crucial parameters to predict in reverse flow. In this thesis, it is aimed to develop and apply mixed-integer linear programming (MILP), scenario-based analysis, and fully fuzzy programming (FFP) methods to maximize the profit for a multi-echelon, multi-components, multi-product, multi-period battery CLSC in Vancouver, Canada. Furthermore, the proposed model is extended to multi-objective to consider the green factors related to plants and battery recovery centers. Fuzzy analytic network process (Fuzzy ANP) is utilized to convert the qualitative factors to the measurable parameters. Then, distance technique and ℇ-constraint method are utilized for solving the multi-objective problem.
    A mega-index for the Americas and its underlying sustainable development correlations
    A mega-index for the Americas and its underlying sustainable development correlations
    Indicators and their composite indices have been embraced as development tools for guiding humanity toward a sustainable destination. In response, public and private organizations have generated hundreds of these metrics, making their application overwhelming to policymakers, planners, and scientists. Past reviews have revealed that a majority of common development indices have theoretical or quantitative shortcomings, supporting that there is no consensus regarding their theoretical basis, design, use, thresholds-of-effect, or validation. In response, this study was designed around four guiding research questions: (i) What are the underlying development themes within a collection of established sustainability indices, and what distinguishes winning locations from losing ones? (ii) Are the three major divisions of sustainability (economic growth, social equity, environmental integrity) equally represented by current sustainable development measuring initiatives? (iii) Could just a few common and freely available indicators capture all present dimensions of sustainable development? (iv) Would a new sustainable development mega-index research paradigm improve humanity’s ability to assess progress toward sustainability? Those questions were investigated using data from 30 mostly contiguous Western Hemisphere nations and three amassing methodological objectives. First, 31 known indices were reduced into underlying dimensions (factors) of sustainable development. Next, those factors were combined (aggregated) into the first mega-index of sustainable development (MISD). Finally, 11 common development indicators were explored regarding collinearity and explanatory power of the sustainable development dimensions and MISD. Seven latent dimensions (sub-metrics) captured over 85% of the variation of the original 31 indices, with socioeconomic themes dwarfing environmental ones. The factors conveyed: (F1) socioeconomic well-being synergies; (F2) economic freedom and democracy; (F3) environmentally efficient happiness; (F4) ecosystem wellbeing; (F5) peace to economic vulnerability tradeoff; (F6) natural resources protection; and (F7) environmental stewardship and risk resilience. MISD is the geometric mean of the seven sub-metrics,which were directed toward sustainability, and rescaled (normalized) 0 (worst case) to 100 (best case). Geographically, this study ranked Belize best overall, followed by Guyana, Panama, Uruguay, and Canada; Barbados ranked worst, preceded by Haiti, Trinidad and Tobago, Mexico, and Cuba. Winning countries were characterized by low population density, increased forestland, decreased urban, and larger country area. Child mortality and population growth rate remained negative predictors of socioeconomic conditions; however per-capita CO2 sacrificed ecological integrity for improved human well-being. Mega-index creation will serve as an important scientific stepping-stone for improving accuracy and simplifying valuations of sustainable development, thus others should follow., Shaker, R. R. (2018). A mega-index for the Americas and its underlying sustainable development correlations. Ecological Indicators, 89, 466-479.
    A methodology for predicting hybrid solar panel performance in different operating modes
    A methodology for predicting hybrid solar panel performance in different operating modes
    When a hybrid solar panel produces thermal energy, it can operate in either hybrid mode, or thermal-only mode. In hybrid mode, the panel produces both electrical power and thermal power, and in thermal-only mode, only thermal power is produced. It has been shown that the thermal performance of a hybrid panel can vary by 15% on average between these two modes, but panel manufacturers are only required to publish performance data for one mode. Other studies in the literature have found a difference in panel thermal performance between these two modes, but they do not discuss a methodology to estimate alternate mode performance using manufacturer-supplied data. To alleviate this gap in the literature, this study presents a novel methodology to estimate alternate mode thermal performance of a hybrid solar panel only using manufacturer-supplied data. To match the panel information that is typically available, the second-order thermal efficiency model is used to estimate thermal performance, and temperature dependent electrical characteristics are used to estimate electrical performance. Indoor testing using a solar simulator was carried out, and the detailed test results are included. Results show that using the proposed modification technique can estimate thermal performance within 4% of actual values on average. Keywords: Solar; Hybrid Panel; PVT Panel; Experimental Data; Efficiency, J. P. Fine, S. B. Dworkin, J. Friedman, “A methodology for predicting hybrid solar panel performance in different operating modes,” Renew. Energ., 130 (2019) 1198-1206
    A mixed methods study of the work patterns of full-time nurse practitioners in Canadian nursing homes
    A mixed methods study of the work patterns of full-time nurse practitioners in Canadian nursing homes
    The aim of this study was to explore the integration of the nurse practitioner role in Canadian nursing homes to enable its full potential to be realised for resident and family care. The objective was to determine nurse practitioners' patterns of work activities. Nurse practitioners were introduced in Canadian nursing homes a decade ago on a pilot basis. In recent years, government and nursing home sector interest in the role has grown along with the need for data to inform planning efforts. The study used a sequential mixed methods design using a national survey followed by case studies. A national survey of nurse practitioners included demographic items and the EverCare Nurse Practitioner Role and Activity Scale. Following the survey, case studies were conducted in four nursing homes. Data were collected using individual and focus group interviews, document reviews and field notes. Twenty-three of a target population of 26 nurse practitioners responded to the survey, two-thirds of whom provided services in nursing homes with one site and the remainder in nursing homes with as many as four sites. On average, nurse practitioners performed activities in communicator, clinician, care manager/coordinator and coach/educator subscales at least three to four times per week and activities in the collaborator subscale once a week. Of the 43 activities, nurse practitioners performed daily, most were in the clinician and communicator subscales. Case study interviews involved 150 participants. Findings complemented those of the survey and identified additional leadership activities. Nurse practitioners undertake a range of primary health care and advanced practice activities which they adapt to meet the unique needs of nursing homes. Knowledge of work patterns enables nursing homes to implement the full range of nurse practitioner roles and activities to enhance resident and family care., Martin‐Misener, R., Donald, F., Wickson‐Griffiths, A., Akhtar‐Danesh, N., Ploeg, J., Brazil, K., . . . Taniguchi, A. (2015). A mixed methods study of the work patterns of full‐time nurse practitioners in nursing homes. Journal of Clinical Nursing, 24(9-10), 1327-1337. doi:10.1111/jocn.12741
    A multidisciplinary collaborative web site for cardiovascular surgery
    A multidisciplinary collaborative web site for cardiovascular surgery
    Key Points: * Patients, healthcare providers, and students have differing information needs in regard to surgical procedures. * Often, separate information sources are designed for each group, resulting in fragmented information. * Interactive, multidisciplinary, collaborative Web site is being developed to address the needs of all members of the healthcare team. Cardiovascular surgical (CVS) settings encompass shared physical spaces that are accessible to patients, physicians, nurses, residents, and other members of the healthcare team.1 Dynamic, fluid interactions are constantly occurring among various members of the team at any point in time.1 Within these interactions, each member seeks to meet unique information and communication needs. For example, patients require information and support for learning and application of new self-care behavior skills, residents and students require mentorship to guide practice, and nurses and physicians require up-to-date empirical and theoretical information to revise and evaluate existing care endeavors. Traditionally, separate resources have been designed and administered for each member of the healthcare team; however, a single intervention that addresses the needs of each member of a multidisciplinary team has not been designed or evaluated.2,3 We developed an interactive, multidisciplinary, collaborative Web site as an intervention designed to address the needs of all members of the healthcare team, including patients. The Web site addresses the needs of postoperative patients, cardiovascular medical residents, nursing students, and other trainees, as well as nurses and physicians. In doing so, the site mimics the collective functioning of the existing healthcare teams within a shared physical space. The Web site can be accessed by different members of the healthcare team anywhere there is a wireless connection, and so it does not depend on shared physical space. Furthermore, it allows for interactive discussion through online chat rooms and open forums. As a result of this Web site, we anticipate an increase in the quality of patient care that is delivered within the CVS setting., Fredericks, S. (2015). A multidisciplinary collaborative web site for cardiovascular surgery. Computers Informatics Nursing, 33(7), 273-277. DOI: 10.1097/CIN.0000000000000167.
    A new life for Old City Hall
    A new life for Old City Hall
    Possible future uses for Toronto’s iconic Old City Hall with case studies from around town and across the globe. In 2015, City of Toronto staff embarked on a study to determine future uses for Old City Hall, a beloved landmark in the heart of Canada’s largest city. This report does not put forth recommendations, but intends to spark creative thinking and inspire a public discussion., Carter-Shamai, S., & Nelischer, C. (2016). A new life for Old City Hall. Toronto: Ryerson University, City Building Institute, Faculty of Community Services.