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• The global uniform exponential stability is established for zero-order delayed systems. • The stability results for impulsive dynamical networks are obtained. • The event-triggered impulsive control (ETIC) is designed to stabilize dynamical networks. • ETIC has lower impulse frequency and control cost than the classic impulsive control. • A non-instantaneous ETIC is proposed to improve the instantanity and discontinuity of ETIC. This paper studies the stability for impulsive dynamical networks (IDN) where different nodes may have different impulse time sequences. By deriving the conditions of global uniform exponential stability for zero-order delayed systems, the criteria of stability for IDN are established. The stability results for IDN are then used to design event-triggered impulsive control (ETIC) for stabilization of continuous-time dynamical networks (CDN). In every node of CDN, three levels of event-triggering conditions are set for ETIC. The exponential stabilization of CDN is shown to be achieved by the designed ETIC and it also shows that the ETIC is robust w.r.t. time-delays. Moreover, a non-instantaneous ETIC (NI-ETIC) is proposed for the stabilization of CDN. Three examples with numerical simulations are given to show that the designed ETIC has lower impulse frequency and cost of control than the classic time-triggered impulsive control. It is also shown that the discontinuity and the instantanity of ETIC are improved by the NI-ETIC. [ABSTRACT FROM AUTHOR]

Steam-Assisted Gravity Drainage (SAGD) has been the preferred thermal method for bitumen recovery from reservoirs in western Canada. To save energy and to be more environmentally friendly, Expanding-Solvent SAGD (ES-SAGD) is herein proposed by adding solvent into the injection vapor. The addition of solvent gives rise to different phase behavior (solvent–steam–bitumen) characteristics than that of the steam-only injection (steam–bitumen) process. Early steam condensation, solvent accumulation in the vapor phase, and convective oil flow near the steam boundary are critical mechanisms of the ES-SAGD process. In this paper, the phase behavior of the steam–solvent–bitumen system and solvent mass transfer in oil are studied through a numerical simulation method. Results show that the dominant mechanism of solvent dissolution in oil is by gas–oil equilibrium, rather than condensate mixing. The dissolved solvent is further convectively delivered into the mobile oil zone by gravity drainage. Under high solvent injection concentration, oil production rate is improved by the significant amount of solvent dissolution in oil. The high injection pressure enhances oil production rate through enlarging the mobile oil zone. In addition, this study proposes a steam–solvent injection strategy to improve the ES-SAGD process. [ABSTRACT FROM AUTHOR]

• A feasibility simulation study of bitumen recovery by applying supercritical water. • Aquathermolysis reaction was considered as the in-situ upgrading mechanism. • Sensitivity analysis was performed considering both geological and operational constraints. As the demand of crude oil is increasing along with depletion of conventional oil, unconventional oil is being extracted to meet the demand worldwide. Heavy oil is one of the largest unconventional crude oil resources, especially in Canada and Venezuela. Thermal recovery is a promising technology developed over the past decades. Particularly, steam injection is considered one of the most effective thermal recovery processes, but it is energy-intensive and is not environmentally friendly. Unlike steam injection, supercritical water flooding (SCWF) is a miscible flooding and in-situ upgrading process and has been experimentally proven as a more effective process than steam injection. However, it has not been field-proven yet. Therefore, numerical simulation is necessary to show its feasibility. In this paper, we present a numerical simulation workflow for SCWF by utilizing CMG-STARS and study its sensitive parameters based on simulation outputs. Simulation results show that SCWF has a better performance due to its gas production from aquathermolysis. Its recovery efficiency can double when compared to steam injection owing to its in-situ upgrading feature within the same production window. SCWF is more suitable in thinner, lower porosity and higher permeability reservoirs. Operational parameters are slightly influencing its reservoir performance, and the influence is negligible as long as a minimum miscible pressure (MMP) is achieved. [ABSTRACT FROM AUTHOR]

Abstract: Anaerobic digestion applied to the organic waste produced in urban environments could provide a critical solution to growing garbage problems while simultaneously reducing external energy requirements. As landfills across Canada and the rest of the world are filled to their limits, a carbon-neutral process which can locally generate electricity and heat while providing up to 50% volatile solid reduction is something to be seriously considered. This paper investigates the feasibility of urban anaerobic digestion, presents four techniques for biogas estimation – ultimate analysis, yield from molecular formula analysis, a novel computer simulation technique using Anaerobic Digestion Model #1 (ADM1), and a literature review of experimentally determined biogas yields. In addition, a case study for small-scale anaerobic digestion system design is presented for an urban building. [Copyright &y& Elsevier]

Abstract: Traditional geostatistical modelling of orebodies and estimation of grade–tonnage curves do not account for the uncertainty of the orebody grades and tonnages. Geological interpretations of complex shapes are often over-constrained, and therefore do not properly identify the location of the ore. In these situations, tonnage is often under-estimated and grade is over-estimated, resulting in orebody models used for mine planning that lead to costly financial decisions. This paper presents an approach aiming to better assess the uncertainty in an orebody model. The approach is applied to Vale''s West Orebody of the Coleman McCreedy Mine, a poly-metallic deposit containing nickel, copper, gold, platinum and palladium. To encapsulate the orebody''s variability and uncertainty, the nickel–copper sulphide mineralized zone is simulated using the single normal equation simulation method. The realizations serve as the orebody models from which the grades of multiple elements are jointly simulated using Min/Max Autocorrelation Factors. The final result is a series of equiprobable representations of the mineralization that incorporates both grade and tonnage uncertainty. The case study indicates that had conventional orebody estimations been used, there would have been a 10% over-estimation of orebody volume, along with significant over-estimation of low-grade material and under-estimation of high-grade material. [Copyright &y& Elsevier]

Abstract: The use of solar passive strategies such as new solar control coatings on windows for buildings with large glazed areas, have recently become important and helpful tools, mainly because these developments help to reduce heat gains and/or losses through transparent materials, diminishing energy loads, and improving the environment inside buildings. This paper shows an assessment of the thermal performance for an office on top of a building with four different configurations of window glass, and their influence on the indoor conditions. The window glass configurations are: clear glass, glass-film (SnS–CuxS solar control coating), double-glass-film, and double clear glass. The simulations were carried out using weather data from Mexico City and Ottawa, which are a good representation of two extreme weather conditions, in order to assess the thermal behaviour inside offices, such as energy loads, costs for air conditioning, and the influence of interior heat transfer coefficient correlations. The results indicate that the glass-film proves to be the less appropriate configuration due to the high temperatures reached on the film surface, which has an impact on the air temperatures inside the office and contributes to increase the energy consumption. In general, the double glass-film configuration results to be adequate for both climates, nevertheless it shows a better performance for Ottawa than Mexico City, where a simple double clear glass would work the same way. [ABSTRACT FROM AUTHOR]

Abstract: This paper describes a detailed investigation into the effects of some of the major design features on the mobility of tracked vehicles over snow. The investigation was carried out using the latest version of an advanced computer simulation model, known as NTVPM, developed under the auspices of Vehicle Systems Development Corporation (VSDC), Ottawa, Ontario, Canada. Results show that the road wheel system configuration, initial track tension (i.e., the tension in the track system when the vehicle is stationary on a level, hard ground) and track width have significant effects on vehicle mobility over snow. On deep snow where the vehicle belly (hull) contacts the snow surface, the location of the centre of gravity (C.G.) of the sprung weight in the longitudinal direction has a noticeable effect on vehicle mobility, as it affects the attitude of the belly and the belly–snow interaction. Based on the investigation, a conceptual high-mobility tracked vehicle for over snow operations is discussed. Results of this study will provide the vehicle designer with guiding principles for the development of high-mobility tracked vehicles. It also demonstrates that NTVPM is a useful and effective tool for design and performance evaluation of tracked vehicles from a traction perspective. [Copyright &y& Elsevier]

Abstract: A dome-covered house is an example of designing sustainable buildings by learning from the optimized biological forms from the nature. The paper presents a 3-D thermal and air flow (3D-TAF) model that estimates the energy needs of a dome-covered house. The model is verified with CFD simulations under the COMSOL Multiphysics environment, experimental measurements and simulation results from similar structures published by other researchers. The use of the dome is expected to reduce the annual heating load of the house by 62.6%, compared with that of an isolated house located in Montreal at latitude. [Copyright &y& Elsevier]

Abstract: This paper describes our preliminary assessment of the system requirements (data, interface and process) for implementation of terms describing lake effects in the Canadian Regional Climate Model. We demonstrate test results for one-dimensional (1-D) and three-dimensional (3-D) models for lake hydrodynamics that have been tested and prepared for interfacing with atmospheric circulation models. We discuss the use of a physical interface model, Canadian Land Surface Scheme (CLASS), that is under consideration for the air–water interface. Our preliminary assessment indicates that it is technically feasible to apply the combination of small shallow lake (slab) model, 1-dimensional vertical model and 3-dimensional circulation model (for very large lakes), together with the current land–air linkage used in regional climate modelling in Canada. Whether we can discern the necessary conditions for invoking each of the models to the lakes present in individual regional climate grid cells is still to be determined. [Copyright &y& Elsevier]