Fast simulation of transient temperature distributions in power modules using multi-parameter model reduction

In this study, a three-dimensional model with multi-parameter order reduction is applied to the thermal modelling of power electronics modules with complex geometries. Finite element or finite difference method can be used to establish accurate mathematical models for thermal analyses. Unfortunately, the resulting computational complexity hinders the analysis in parametric studies. This study proposes a parametric order reduction technique that can significantly increase simulation efficiency without significant penalty in the prediction accuracy. The method, based on the block Arnoldi method, is illustrated with reference to a multi-chip SiC power module mounted on a forced air-cooled finned heat sink with a variable mass flow rate

A First Assessment of the Elemental Composition of Atmospheric Aerosols in the Canadian Oil Sands Region

Canadian Oil Sands, which comprise 97% of Canada’s 176 billion barrels of proven oil reserves, are located beneath 140,200 km2 of boreal forests, prairies and wetlands, and are the second largest known deposit of crude oil in the world. As such, this region has experienced rapid industrial development, which resulted also in increasing industrial air emissions, primarily from bitumen upgrading and mine vehicle fleet operations. This rapid development has led to concerns regarding health risk to humans, and other terrestrial and aquatic wildlife associated with exposure to toxic contaminants, especially metals and polycyclic aromatic compounds (PACs) particularly along the Athabasca River and its watershed. Canada’s Minister of the Environment announced that Environment Canada (EC) will jointly lead, in collaboration with Government of Alberta and relevant stakeholders, the development and implementation of an enhanced monitoring system in the Oil Sands region to provide information on the state of the air, water, land andbiodiversity. This work presents preliminary data on the first assessment of elemental composition of fine particulate matter (particles<2.5 mm in diameter; PM2.5) at 3 air quality sites in close proximity to Oil Sands processing activities. Since December 2010, integrated 24 hour air samples were collected every sixth day on a 47-mm Teflon filters using Thermo Fisher Partisol 2000-FRM samplers operated by the National Air Pollution Surveillance (NAPS) network that involves EC and the Canadian provinces and territories. All samples including laboratory, travel and field blanks were subjected to gravimetric determination of PM2.5 mass and energy dispersive X-ray fluorescence (ED-XRF) analysis for 46 elements. Since ED-XRF is a non-destructive technique, PM2.5 samples were subsequently analyzed for 37 trace elements including rare earth elements using inductively-coupled plasma mass spectrometry (ICP-MS) combined with microwave-assisted acid digestion. The resulting data will be discussed

Concentrations of Platinum Group Elements (Pt, Pd, Rh) in Airborne Particulate Matter (PM2.5 and PM10-2.5) Collected at Selected Canadian Urban Sites: a Case Study

Increasing environmental concentrations of platinum group elements (PGEs), in particular platinum (Pt), palladium (Pd) and rhodium (Rh), from catalytic converters has been reported worldwide. Initially it was believed that the emitted PGEs remain in the roadside environment, but recent studies have shown that fine PGE-containing particles can be transported and distributed at regional and long-range levels. Therefore, the monitoring of PGEs in airborne particulate matter (PM) is important for the estimation of potential risks to human health and to the ecosystem. The aim of this study is to present the first results from an analysis on the concentration and distribution of Pt, Pd and Rh in PM collected on Teflon filters at two selected urban sites (Toronto, Ontario; Edmonton, Alberta) collected within the Canadian National Air Pollution Surveillance (NAPS) network. In this work, a quadruple inductively coupled plasma mass spectrometry (ICP-MS), combined with microwave assisted acid digestion using aqua regia was used. A cation exchange separation was used to alleviate the matrix-induced spectral and nonspectral interferences prior to ICP-MS analysis. To obtain sufficient material needed for PGEs analysis, fine PM (particles with aerodynamic diameter less than 2.5 mm; PM2.5) and coarse PM (with aerodynamic diameter between 2.5 and 10 mm; PM10-2.5) samples were combined into composite samples on a seasonal basis. The obtained results will be discussed and compared with literature data