Overview and details of the sessions of this conference. Please select a date or location to show only sessions at that day or location. Please select a single session for detailed view (with abstracts and downloads if available).
Session Chair: Kris Dick Session Chair: Qiang Zhang
1:50pm - 2:10pm
Effectiveness of negative air ionization for removing viral bioaerosols in an enclosed space
Desmond Essien, Kevin Coombs, David Levin, Qiang Zhang
University of Manitoba
Air ionization is gaining acceptance as a method of choice for the purification of air. The method has been applied successfully to remove non-pathogenic particulates, such as smoke, dust, and pollen, from air. However, little is known on its effectiveness for the purification of air laden with pathogenic microorganisms. This study aimed to investigate the effectiveness of air ionization in removing aerosols loaded with viral pathogens. Reovirus bioaerosols were first generated into an airtight chamber. Subsequently, an air ionization system located within the chamber was activated to generate negative ions. Using biosamplers, samples were taken from within the chamber at predetermined time intervals (5 minutes, 10 minutes, and 30 minutes). A laser particle analyzer was utilized to monitor the size distribution and concentration of the bioaerosols prior and after generation of negative ions. Plaque assays were conducted to determine the infectivity of the sampled air. Preliminary results indicated that the air ionization system significantly reduced the infectivity of reovirus.
2:10pm - 2:30pm
Evaluation of Cloud Cover Based Model for Simulation of Hourly Global Solar Radiation in Western Canada
Md Shamim Ahamed, Huiqing Guo, Karen Tanino
University of Saskachewan, Canada
The solar radiation data are very important for building thermal performance and solar application analysis. However, the continuous time series solar radiation data are not available for the most part of the world and the measured data available from a solar station become less accurate for a given location beyond 50 km from the measuring station. Cloud cover based solar radiation models (CRM) are very simple and convenient as the models require only cloud cover data which are mostly available from the meteorological stations. In this study, the performance of a cloud cover based solar radiation model (Kasten-Czeplak model) with original and locally fitted coefficient were evaluated for estimating the hourly global solar radiation for four different locations of Western Canada. The average R2, MBE, and RMSE are 0.82, -28.1 W m-2, and 109 W m-2, respectively, for the model with original coefficients, and 0.89, 1.2 W m-2, 76 W m-2 with locally fitted coefficients. Results show that Kasten-Czeplak model quit successfully estimate the hourly solar radiation of four different locations in Western Canada, but the use of local coefficient significantly improves the model accuracy. Also, the analysis of model performance indicates that the model with original coefficients has limited accuracy under intermediate cloud cover condition.
2:30pm - 2:50pm
Specific pressure value fo design safe loose hay storage cells
Eric Nadeau1, Virginia Mercier-Giguere1, François Turcotte1, Stephane Godbout2, Frédéric Peleltier2, Joahnn Palacios2, Yves Bédard3, Jocelyn Marceau3
1Université Laval; 2IRDA; 3MAPAQ
The concept of loose hay storage is being brought forward in Quebec. Traditionally, hay is cut and left in the field for a period of 72 hours..Consequently, the farmer must rely on favourable weather conditions for a period of 3 subsequent days.and recent weather observations illustrate that such ideal conditions are rare. The idea of harvesting hay after only 36 hours in the field and then drying it in a storage cell has been proposed. Once the drying is complete, the hay is removed from the cell and compressed into hay bales. This drying cell is equipped with a system which forces an air circulation of either positive or negative pressure from bottom to top of the cell. The bottom of the cell is constructed of a metal grating to let air circulate through the cell. Currently, the literature does not provide values that can be used directly by engineers to design wall and flooring sytem. The objective of the present study is to bring available data to design a cell wall capable of resisting the lateral load caused by the loose hay while keeping the costs of materials to a minimum. Using the values presented in the literature, the estimated lateral loads vary between 4.75 and 6.87 kPa for an average value of 5.6 kPa. The paper will suggest calculation methodology taking into account the limit state design and the value variability for designing adequate and safe structure.
2:50pm - 3:10pm
Thermal environment modelling of the Chinese mono-slope solar greenhouse for cold regions
Shuyao Dong, Huiqing Guo
University of Saskatchewan, Canada
The high heating cost of greenhouse production in winter continues to be a barrier for the greenhouse growers, thus limiting the growth of greenhouse industry in Saskatchewan which has 60-million-acre farmland. On the other side, mono-slope solar greenhouses do not primarily rely on supplemental heating but on solar energy to maintain indoor temperature. Fortunately, Saskatchewan has the highest sunshine hours all the year round which provides a favorable environmental condition for the establishment and development of mono-slope solar greenhouses, cutting down heating cost greatly.
This research project intends to simulate energy consumption of solar greenhouse production established in Saskatchewan using a simulation model. This model has limited uses with its existing setup. The first step is to modify this model to make it applicable to the cold climate in Saskatchewan, including meteorological year data input, double-layer front roof structure, inner and outer thermal blanket cover during the night, and so on. Next, the modified model will be run under various climatic and greenhouse operating conditions to obtain energy consumption results. Finally, TRNSYS software will be used to simulate the same type of mono-slope solar greenhouse and then the energy consumption results of the two models will be compared.
Expected result for this greenhouse heating simulation model is satisfactory simulation results which include energy consumption, indoor thermal environment, etc. With these results, greenhouse growers will know the difference in energy consumption between gutter-connected greenhouses and solar greenhouses, thus making winter local greenhouse vegetable production economical for Canadian Prairies.