Entity

Time filter

Source Type

Bells Corners, Canada

Rissafi Y.,Canada Revenue Agency | Talbi L.,University of Quebec at Outaouais | Ghaddar M.,University of Quebec at Outaouais
IEEE Transactions on Antennas and Propagation | Year: 2012

An experimental characterization of the ultrawideband (UWB) propagation channel in an underground mine environment over the frequency range from 3 GHz to 10 GHz is reported in this paper. Two kinds of antennas, directional and omnidirectional, were used to investigate the effect of the antenna directivity on the path loss propagation and on the time dispersion parameters in both line-of-sight (LOS) and no-line-of-sight (NLOS) underground galleries. The measurement and simulation results show that the path loss exponents in an underground environment are larger than their counterparts in an indoor environment. In NLOS, the directional-directional (Direct-Direct) antenna combination showed better radiation efficiency for reducing the time dispersion parameters while the omnidirectional-omni directional (Omni-Omni) case resulted better performance in term of path loss. After extracting the channel parameters, a statistical modeling of the UWB underground channel based on data measurements was conducted. © 2006 IEEE. Source


Ensign P.C.,Wilfrid Laurier University | Lin C.-D.,Canada Revenue Agency | Chreim S.,University of Ottawa | Persaud A.,University of Ottawa
International Journal of Technology Management | Year: 2014

This paper presents the findings from a qualitative study on the extent to which three dimensions of proximity - geographic, cognitive, and organisational - impact knowledge transfer and innovation post-merger and acquisition (M&A). Findings show that the elements of proximity substantially influence both knowledge transfer and innovation although the nature of the impact varies and is influenced by the type of management interventions or lack thereof post-M&A. Copyright © 2014 Inderscience Enterprises Ltd. Source


Gao J.,Canada Revenue Agency | Martinez D.M.,Pulp and Paper Research Institute of Canada | Martinez D.M.,University of British Columbia | Olson J.A.,Research and Industrial Partnerships | Olson J.A.,University of British Columbia
Tappi Journal | Year: 2016

Latency removal in the mechanical pulping process occurs in a continuous stirred-tank reactor and non-ideal mixing lowers the performance. In order to optimize the latency removal process and reduce the energy consumption in the operation, a kinetic study was carried out. In the study, the phenomenon of latency and knowledge related to latency removal were critically reviewed and discussed. Latency removal was characterized by the change of Canadian Standard Freeness (or freeness), and its dependences on treatment conditions, i.e., disintegration temperature, power input, pulp consistency and time, were determined. Kinetic models of latency removal for secondary refiner thermomechanical (TMP) and bleached chemithermomechanical (BCTMP) pulps have been developed, which were based on the rate of latency elimination characterized by the decrease of freeness. Application: These original models are available for use as a tool to predict the change of freeness in the industrial latency removal process for the purpose of optimizing the latency removal process and reducing the energy consumption in the operation. Source


Di Ciano M.,University of Waterloo | Caron E.J.F.R.,University of Waterloo | Caron E.J.F.R.,Canada Revenue Agency | Weckman D.C.,University of Waterloo | Wells M.A.,University of Waterloo
Metallurgical and Materials Transactions B: Process Metallurgy and Materials Processing Science | Year: 2015

Fusion™ casting is a unique Direct Chill continuous casting process whereby two different alloys can be cast simultaneously, producing a laminated ingot for rolling into clad sheet metal such as AA3003/AA4045 brazing sheet. Better understanding of the wetting and interface formation process during Fusion™ casting is required to further improve process yields and also explore use of other alloy systems for new applications. In this research, AA3003-core/AA4045-clad ingots were cast using a well-instrumented lab-scale Fusion™ casting system. As-cast Fusion™ interfaces were examined metallurgically and by mechanical testing. Computational fluid dynamic analyses of the FusionTM casts were also performed. It was shown that the liquid AA4045-clad alloy was able to successfully wet and create an oxide-free, metallurgical, and mechanically sound interface with the lightly oxidized AA3003-core shell material. Based on the results of this study, it is proposed that the bond formation process at the alloys interface during casting is a result of discrete penetration of AA4045 liquid at defects in the preexisting AA3003 oxide, dissolution of underlying AA3003 by liquid AA4045, and subsequent bridging between penetration sites. Spot exudation on the AA3003 chill cast surface due to remelting and inverse segregation may also improve the wetting and bonding process. © 2015, The Minerals, Metals & Materials Society and ASM International. Source


Di Ciano M.,University of Waterloo | Caron E.J.F.R.,University of Waterloo | Caron E.J.F.R.,Canada Revenue Agency | Weckman D.C.,University of Waterloo | Wells M.A.,University of Waterloo
Metallurgical and Materials Transactions B: Process Metallurgy and Materials Processing Science | Year: 2015

Fusion™ casting is a unique Direct Chill continuous casting process whereby two different alloys can be cast simultaneously, producing a laminated ingot for rolling into clad sheet metal such as AA3003/AA4045 brazing sheet. Better understanding of the wetting and interface formation process during Fusion™ casting is required to further improve process yields and also explore use of other alloy systems for new applications. In this research, AA3003-core/AA4045-clad ingots were cast using a well-instrumented lab-scale Fusion™ casting system. As-cast Fusion™ interfaces were examined metallurgically and by mechanical testing. Computational fluid dynamic analyses of the FusionTM casts were also performed. It was shown that the liquid AA4045-clad alloy was able to successfully wet and create an oxide-free, metallurgical, and mechanically sound interface with the lightly oxidized AA3003-core shell material. Based on the results of this study, it is proposed that the bond formation process at the alloys interface during casting is a result of discrete penetration of AA4045 liquid at defects in the preexisting AA3003 oxide, dissolution of underlying AA3003 by liquid AA4045, and subsequent bridging between penetration sites. Spot exudation on the AA3003 chill cast surface due to remelting and inverse segregation may also improve the wetting and bonding process. © 2015 The Minerals, Metals & Materials Society and ASM International Source

Discover hidden collaborations