The growing interest in industrial applications of the hemp plant requires alternative solutions for disposing of hemp waste. At the same time, the concrete industry is seeking ways to reduce its environmental impact, which could be realized by partially replacing Portland cement with more sustainable materials. In this study, a two-step valorization strategy of hemp waste is explored, including the use of hemp waste as biofuel and the addition to concrete of the biofuel by-product, hemp ash, as partial cement replacement. Hemp waste was incinerated in a muffle furnace at different combustion regimes and the residual hemp ash was analyzed before being added to some concrete mixes. Concretes with different hemp ash replacements (5–25% by cement weight) were tested for compression strength, air content, workability, and water absorption. Results showed that hemp ash has the potential to be added to concrete as a filler to reduce environmental impact and costs at 5% cement replacement., Peer reviewed, Article, Received: December 10, 2019. Accepted: March 27, 2020. Published online: April 2, 2020., Incineration, Hemp biomass, Biofuel, Hemp ash, Supplementary cementing materials, Cement, Concrete
Carbonation in concrete is a natural chemical process by which atmospheric CO2 reacts with calcium oxide in the Ca(OH)2 and CSH phases in hydrated cement paste to form CaCO3. The carbonation rate in the atmosphere is too slow for laboratory testing, and therefore, it is usually accelerated by using relatively higher CO2 concentrations. However, there exists some disagreement as to what CO2 concentration, humidity and temperature should be specified when conducting an accelerated carbonation test. In this study, samples of hydrated cement paste were carbonated at different CO2 concentrations, and analysed using the x-ray diffraction technique. The results show that the morphology of CaCO3 formed at higher CO2 concentrations is different from that of CaCO3 formed at natural concentrations. It should be recognized that the diffusion coefficient measured at higher concentrations will not be exactly the same as that from naturally carbonating concrete due to the formation of these morphologically different products., Article, Published.
General report about exploratory study of how post-secondary students with mathematics learning disabilities use and adapt their use of their personal electronic devices to support their academic studies., Not peer reviewed, Article
For better or for worse, many of the simple, unprocessed, and easily identifiable herbs of a bygone era can be found in retail commerce only rarely and with some degree of difficulty. Many modern botanical products intended for health-related purposes are, for the most part, quite complicated, often requiring additional testing for authentication of identity and for the presence of accidental or intentional adulterants, including contaminants such as heavy metals, pesticides, noxious microbes, and mycotoxins. As knowledge on the composition and properties of herbs has evolved, so too has the ability to evaluate those properties (e.g., marker compounds) using technology. The modern world also superimposes itself on commerce in the form of smelters, internal combustion engines, fecal coliforms, leaded gasoline, pesticides, prescription drugs, and other noxious substances that necessitate testing in addition to evaluating the inherent properties of the raw materials and finished products. No evaluation of herbal quality would be complete without some means of assuring that these and other unintentional contaminants are absent. In addition to an individual manufacturer’s desire to create and sell only the highest quality products, there are significant regulatory requirements surrounding the sale of botanical goods. Whether they are called natural health products (Canada), therapeutic goods (Australia), dietary supplements (United States), or phytomedicines (Europe), there are regulatory requirements to set specifications and to test for conformity with those specifications. Thus, the laboratory enters the scene., Article, Published.
Proceedings of 3rd International Building Physics Conference: 27 August 2006, Montreal, QC. A two-dimensional heat, air and moisture transport model called hygIRC is adapted to simulate a well-documented field exposure of an aerated concrete wall section. Difficulties are encountered due to a few missing information on boundary conditions of the exposure and hygrothermal properties of aerated con-crete. The paper presents how these inadequacies were overcome to simulate the hygrothermal behavior of the wall section. Appropriate assumptions were made due to justifiable reasons. Then the model provides temporal and spatial distributions of temperature and relative humidity for an extended period that are in ex-cellent agreement with the documented field data. The paper presents the justifications for the assumptions and the comparison of experimental and simulation results., Conference paper, Published. A version of this document is published in: 3rd International Building Physics Conference, Montreal, QC., August 27, 2006, pp. 321-328.
Proceedings of Thermal Performance of the Exterior Envelopes of Whole Buildings XII International Conference, At Clearwater Beach, Florida, USA, December 2013.
Based on analysis of the drying and wetting potentials of a particular local climate, designers choose wall systems with or without an air gap between a sheathing membrane and a cladding layer. In addition to the capillary break that the air gap provides, thereby reducing the moisture transfer from wet cladding to the interior of the wall, the airspace will add the thermal resistance of the wall system and reduce the heat flow across the wall system. These moisture and thermal performances are straightforward to understand if the air in the air cavity is assumed to be a “still air.” In this paper, an experimental study is undertaken to under-stand the impact of airflow through an air cavity on the moisture and thermal performance of wall systems. To achieve this objective three test panels are instrumented and monitored in the field-experimental setting: one with no air gap, another one with an air gap but restricted airflow, and the third one with an air gap and open for airflow. The second and third wall systems have the same air gap width but different top flashing designs creating vented and ventilated wall systems. For the wall systems’ orientation and boundary conditions considered in this study, the wall with no air gap accumulates relatively high moisture content on the sheathing board, stud, and bottom plate and also has high moisture content changes in a year cycle when compared to the vented and ventilated wall systems. In general, the hygrothermal performances of vented and ventilated wall systems are comparable. During the winter period when relatively high moisture accumulation occurs, the upper section of the ventilated wall system shows slightly lower moisture content compared to that of the vented wall system. The temperature readings of the sheathing boards in the vented and ventilated wall systems are slightly warmer than that of the wall with no air gap for 85.5% and 73% of the time (based on hourly data of a year), respectively. For the balance of a period of time, the sheathing boards in the walls with an air cavity are slightly cooler than that of the wall with an air gap. Although the low temperature on the sheathing board, which is caused by solar radiation-induced airflow, is beneficial during a cooling season, the air gap and the associated airflow may reduce the heat gain that may be obtained from solar radiation during the heating season. The implications of air cavity and flashing design (airflow rate) on the heating and cooling load calculations of different orientations, wall configurations, and climate require further investigation., Conference paper, Published.
Proceeding of the 4th International Building Physics Conference: 15 June 2009, Istanbul, Turkey.
This paper provides highlights of the research work carried out at the National Research Council Canada, Institute for Research in Construction on assessing the hygrothermal performance of wall systems that included this innovative vapour retarder (Note: Vapour Barrier in Canadian terminology is equivalent to Vapor retarder in US terminology). The performance of walls was assessed when subjected to eastern coastal climate conditions of Halifax, one of the four Canadian climatic locations used in this study. A wood-framed stucco clad wall was the reference assembly. Results from different cases based on the variation of vapour control strategies and their effect on the hygrothermal performance of the wall systems are analysed. The results for the Halifax climate location indicate that the installation of a humidity controlled, innovative vapour retarder is a recommendable solution for the envelope design of residential buildings of these locations with moderate or high water vapour permeance of the interior paint. In this study, the advanced hygrothermal tool, hygIRC, was used to perform the hygrothermal performance analysis of the wall systems., Peer reviewed article, Published. A version of this document is published in: 4th International Building Physics Conference, Istanbul, Turkey, June 15-18, 2009, pp. 1-8.
Proceedings of 12th Canadian Conference of Building Science and Technology: 06 May 2009, Montreal, QC.
The hygrothermal performance of wood-frame wall with stucco cladding exposed to the coastal climate of Vancouver, BC, is studied. The primary objective of the study is to compare the moisture management performance of two vapour barriers: the relatively new SmartVapour Retarder (SVR) and commonly used Polyethylene sheet. For a reference purpose a wood-frame wall with no vapour barrier is considered as well. The performances of these three walls, which are exposed to the same indoor and outdoor climatic loads, are compared with respect to their dynamic responses to two simulation variables: interior moisture load (simulated water intrusion in the stud cavity) and paint on the interior gypsum board. The water intrusion is assumed to be through defect areas and the quantity is correlated with the amount of wind-driven rain that the wall is exposed to. The hygrothermal simulation results suggest that adoption of SVR as a vapour barrier yields better moisture management of the sheathing board (OSB) for any conditions considered in this paper including internal moisture load and interior paint. But, in coastal climate, it may have adverse effect on the moisture management of the interior gypsum board, in cases where water leaks into the cavity and the interior gypsum board is painted with low-vapour permeance paint., Peer reviewed article, Published. A version of this document is published in: 12th Canadian Conference of Building Science and Technology, Montreal, QC, May 6-8, 2009, pp. 1-12
14th International Conference on Indoor Air Quality and Climate (Indoor Air 2016), July 3-8, 2016, Ghent, Belgium. An indoor to attic air leakage and vice-versa significantly affect indoor air, thermal comfort and the hygrothermal performance in both living space and unconditioned space. In cold and marine climates an air leakage from living space to an attic brings a relatively high relative humidity to the attic space. This effect is primarily responsible for condensation in attic structural parts such as roof sheathings. In this paper, the hygrothermal performance of a ventilated attic in wet costal climates under different ceiling air leakage is studied. A benchmarked whole building Heat-Air-Moisture model named HAMFit is used to study hygrothermal performance of ventilated attics in marine climates. The attic is modelled as 2-dimensional geometry with coupled heat transfer, moisture transport and a turbulence Computational Fluid Dynamics through attic space and porous structural parts of the attic. A vent ratio of 1/300 and three types normalized leakage area (tight, normal and leaky) are used to analyse how the moisture transport behaves in ventilated space. A winter weather data of city of Vancouver, BC is used to represent a wet marine climate. Our findings show specific locations in the attic structure are more exposed to moisture related problems and the air circulation and temperature distribution due to ventilation under multiple ceiling air leakage scenarios are presented. Hygrothermal performance of ventilated attic in marine climate under different ceiling air tightness., Conference paper, Published.
Proceedings of Thermal Performance of the Exterior Envelopes of Whole Buildings X International Conference: 02 December 2007, Clearwater, Florida. Testing was conducted to determine those construction material properties that affect the movement of heat, air, and moisture in building envelopes. The paper reports the density, thermal conductivity, equilibrium moisture content, water vapor permeability, water absorption coefficient, liquid diffusivity, and air permeability of twenty-three building materials commonly used in North American including: exterior claddings, exterior sheathing boards, membranes and insulations. The paper also discusses the experimental and analytical procedures used to determine these properties., Conference paper, Published. A version of this document is published in: Proceedings of Thermal Performance of the Exterior Envelopes of Whole Buildings X, Clearwater, Florida, Dec. 2-7, 2007, pp. 1-16.
Fibre properties and the biochemical composition of cell walls are important traits in many applications. For example, the lengths of fibres define the strength and quality of paper, and lignin content is a critical parameter for the use of biomass in biofuel production. Identifying genes controlling these traits is comparatively difficult in woody species, because of long generation times and limited amenability to high-resolution genetic mapping. To address this problem, this study mapped quantitative trait loci (QTLs) defining fibre length and lignin content in the Arabidopsis recombinant inbred line population Col-4×Ler-0. Adapting high-throughput phenotyping techniques for both traits for measurements in Arabidopsis inflorescence stems identified significant QTLs for fibre length on chromosomes 2 and 5, as well as one significant QTL affecting lignin content on chromosome 2. For fibre length, total variation within the population was 208% higher than between parental lines and the identified QTLs explained 50.58% of the observed variation. For lignin content, the values were 261 and 26.51%, respectively. Bioinformatics analysis of the associated intervals identified a number of candidate genes for fibre length and lignin content. This study demonstrates that molecular mapping of QTLs pertaining to wood and fibre properties is possible in Arabidopsis, which substantially broadens the use of Arabidopsis as a model species for the functional characterization of plant genes., Peer-reviewed article, Published. Received 3 April 2012; Revised 11 October 2012; Accepted 15 October 2012.
This study investigates the potential cost and emissions reductions that result from an increase in electricity transmission capacity between Canada's two westernmost provinces: Alberta, a fossil fuel dominated jurisdiction, and British Columbia, a predominantly hydroelectric jurisdiction. A bottom-up model is used to find the least cost electricity generation mix in Alberta and British Columbia under different carbon policies. The long-term evolution of the electricity system is determined by minimizing net present cost of electricity generation for the time span of 2010–2060. Different levels of intertie capacity expansion are considered together with a variety of carbon tax and carbon cap scenarios. Results indicate that increased intertie capacity reduces the cost of electricity and emissions under carbon pricing policies. However, the expandable intertie does not encourage greater adoption of variable renewable generation. Instead, it is used to move low-cost energy from the United States to Alberta. The optimal intertie capacity and cost reduction of increased interconnectivity increases with more restrictive carbon policies., Peer-reviewed article, Published. Received 3 March 2016, Revised 23 September 2016, Accepted 12 October 2016, Available online 15 November 2016.