BCIT Citations Collection
Collection of published works from BCIT researchers, faculty, and instructors.
Pages
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- Climate change-induced carbonation of concrete infrastructure
- There is a nearly unanimous consensus among scientists that increasing greenhouse gas emissions, primarily carbon dioxide generated by human activity, are effecting the Earth's climate. For many key parameters, the climate system is already moving beyond the patterns of natural variability within which our societies and economies have developed and thrived. These parameters include global mean surface temperature, sea-level, ocean and ice sheet dynamics, and extreme climatic events. There is a significant risk that many of the trends will accelerate, leading to an increasing risk of abrupt or irreversible climatic shifts. One overlooked area of research is the impact of climate change on concrete infrastructure. Concrete structures form an essential part of the world. Climate change could potentially affect the durability of concrete infrastructure. In this paper, the findings of a study at the University of British Columbia which demonstrate a long-term risk to the durability of steel-reinforced concrete structures in some parts of the world via accelerated carbonation-induced corrosion are presented. Research demonstrates that service lifespans of structures will be affected in the long term, with the need for earlier repairs unless the adverse effects of climate change are taken into account at the time of design., Peer-reviewed article, Published.
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- Communication technologies for BCIT Smart Microgrid
- Proceeding of IEEE PESConference, Washington DC, Jan 2012. This paper conducts a topical review of the requirements for end-to-end communication systems as the backbone for command and control within Smart Microgrids. The initial lab and field test results from the evaluation of WiMAX and ZigBee as BCIT Microgrid communication network are presented., Conference paper, Published.
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- Community Energy Storage impacts on smart grid adaptive Volt-VAR Optimization of distribution networks
- Accepted in 7th International Symposium on Power Electronics for Distributed Generation Systems (PEDG 2016), Jun. 2016, Vancouver, BC, Canada. This paper aims to investigate Community Energy Storage (CES) impacts on AMI-based Volt-VAR Optimization (VVO) solutions for advanced distribution networks. CES is one of the technologies employed to improve system stability, reliability and quality. As such, it could have considerable impacts on voltage control, reactive power optimization and energy conservation. Conservation Voltage Reduction (CVR) is one of the main tasks of advanced VVO engines in distribution networks. Moreover, in order to check the performance of the discussed VVO engine in the presence of CES during peak time intervals, 33-node distribution feeder is employed. The results of this paper show significant improvement in the performance of the VVO engine when CES is forced to discharge in peak times. Moreover, the results present how CES could affect Volt-VAR Control Component (VVCC) switching and how it affects the energy conservation efficiency., Conference paper, Published.
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- Comparisons of large (Vaccinium macrocarpon ait.) and small (Vaccinium oxycoccos L., Vaccinium vitis-idaea L.) cranberry in British Columbia by phytochemical determination, antioxidant potential, and metabolomic profiling with chemometric analysis
- There is a long history of use and modern commercial importance of large and small cranberries in North America. The central objective of the current research was to characterize and compare the chemical composition of 2 west coast small cranberry species traditionally used (Vaccinium oxycoccos L. and Vaccinium vitis-idaea L.) with the commercially cultivated large cranberry (Vaccinium macrocarpon Ait.) indigenous to the east coast of North America. V. oxycoccos and V. macrocarpon contained the 5 major anthocyanins known in cranberry; however, the ratio of glycosylated peonidins to cyanidins varied, and V. vitis-idaea did not contain measurable amounts of glycosylated peonidins. Extracts of all three berries were found to contain serotonin, melatonin, and ascorbic acid. Antioxidant activity was not found to correlate with indolamine levels while anthocyanin content showed a negative correlation, and vitamin C content positively correlated. From the metabolomics profiles, 4624 compounds were found conserved across V. macrocarpon, V. oxycoccos, and V. vitis-idaea with a total of approximately 8000–10 000 phytochemicals detected in each species. From significance analysis, it was found that 2 compounds in V. macrocarpon, 3 in V. oxycoccos, and 5 in V. vitis-idaea were key to the characterization and differentiation of these cranberry metabolomes. Through multivariate modeling, differentiation of the species was observed, and univariate statistical analysis was employed to provide a quality assessment of the models developed for the metabolomics data., Peer-reviewed article, Published.
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- Computations of post-inductive dynamics in axolotl heart formation
- This paper reports modelling of heart localization in the axolotl (Ambystoma mexicanum). The region of heart specification in the mesoderm defined by classical induction from the endoderm is larger than the area of final myocardial differentiation. For localizing the area of differentiation within the area of specification, we postulate a mesoderm in response to induction from the endoderm. This mechanism generates a spatial pattern for two chemicals, an activator and an inhibitor, corresponding to the area of myocardial differentiation. We postulate a diffusible chemical rescuer, which is absent in the cardiac lethal mutant, and which is a precursor to the reaction-diffusion mechanism. The activator, inhibitor, rescuer, and product of endodermal induction are presented in an enzyme mechanism with rate equations similar to the Gierer-Meinhardt equations. These equations were solved numerically in both one and two spatial dimensions. We have attained quantitative agreement with the experimental data for sizes of tissue regions and for times to heartbeat. Experiments modelled include wild-type heart localization as well as both in vitro and in vivo rescue of cardiac lethal mesoderm with wild-type mesoderm. Based upon the parameters necessary to model heart localization, we make a series of predictions. We predict: a specific profile for the endodermal inducer gradient; the possibility of producing multiple hearts in vivo; and a greater contribution to the heart from the wild-type mesoderm for in vivo transplants with cardiac lethal mesoderm. We make some suggestions as to the possible chemical nature of the substances in the model. We indicate that the inhibitory field and mechanochemical theories are probably not as promising as reaction-diffusion for the mechanism of heart localization., Peer-reviewed article, Published. Received January 24, 1994; accepted April 7, 1994.
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- Computer representation to support conceptual structural design within a building architectural context
- Computer support for conceptual design of building structures is still ineffective, mainly because existing structural engineering applications fail to recognize that structural design and architectural design are highly interdependent processes. This paper describes a computer representation called StAr (structure-architecture), aimed to act as a common basis for collaboration between architects and engineers during conceptual structural design. The StAr representation describes the structural system as a hierarchy of entities with architectural counterparts, which enables the direct integration of the structural system to the building architecture as well as engineering feedbacks to the architect at various abstraction levels. The hierarchical structural description implements a top-down design approach where high-level structural entities, which are defined first, facilitate the configuration of lower-level entities whose functions in turn contribute to those of the higher-level wholes that they belong to. The representation has been built on top of a geometric modeling kernel that allows reasoning based on the geometry and topology of the design model, which is paramount during early design stages. A proof-of-concept software prototype, called StAr prototype, has been developed and a test example demonstrates how the representation can support the different activities that take place during the conceptual design of building structures., Peer reviewed, Technical paper, Received: September 16, 2004 ; Accepted: October 27, 2004 ; Published online: March 01, 2006, StAr, Conceptual design
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- Concept proposal for a detachable exoskeleton-wheelchair to improve mobility and health
- Proceedings of 2013 IEEE International Conference on Rehabilitation Robotics, June 24-26, 2013 Seattle, Washington USA. Wheelchair use has consequences to quality of life in at least two areas: 1) health issues such as pressure sores and chronic overuse injury; and 2) access problems due to the inaccessible nature of the built and natural environments that are most amenable to upright postures. Even with these concerns, wheelchairs are still the best form of mobility for many people (e.g. they are relatively easy to transfer into and propel). However, wheelchairs are simply not transformative, i.e. they do not allow a person with a disability to attain a level of mobility performance that approaches that of their non-disabled peers, nor do they typically allow for face to face interactions and full participation in the community. Wheelchairs also do not typically support ongoing therapeutic benefits for the user. To address the inadequacy of existing wheelchairs, we are merging two evolving technologies into a coherent new mobility device. The first is dynamic wheeled mobility, which adds significant functionality to conventional wheelchairs through the use of on-the-fly adjustable positioning. The second is powered walking exoskeletons, which enable highly desired standing and walking functions, as well as therapeutic benefits associated with rehabilitation gait training. Unfortunately, exoskeletons have significant usability concerns such as slow speed, limited range, potential to cause skin issues, and difficult transfers. A new concept of docking a detachable exoskeleton to a wheeled frame has been developed to address these issues. The design goal is a single mobility device that not only optimizes daily activities (i.e. wheelchair seating and propulsion with dynamic positioning), but also serves as an easy-to-use rehabilitation tool for therapeutic benefits (i.e. a detachable powered exoskeleton for walking sojourns). This has significant potential benefits for the lives of people with mobility impairments., Conference paper, Published.
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- Condensation risk assessment of window-wall facades under the effect of various heating systems
- In northern coastal climates, surface condensation often occurs in fenestration systems during winter. The most common contributors of this phenomenon are air leakage, thermal bridging, local convection and radiation. (i.e. boundary conditions). Researchers and industry experts typically focus on improving designs of fenestration and developing different strategies to deal with air leakage and thermal bridging. However, the effects of local convection and radiation on window condensation are often overlooked. This project focuses on investigating the ways different heating systems internet with window-wall systems via convection and radiation heat exchanges, and their effects on surface condensation. The three most common heating systems for multi-unit residential building (MURB) arc considered: electric baseboard, hydronic radiant floor and forced air system. Each heating system provides vastly different indoor conditions due to differences in thermal stratification, room air distribution and location of heat sources. These differences have direct impacts on window performance and potentially increase risk of condensation. In this project, the following questions are investigated: How significant is impact of room air flow on condensation risk in window-wall systems? Are empirical film coefficients sufficient for predicting condensation risk of window-wall units' What are the differences between each of the heating systems on condensation risk? This project designed a methodology in an attempt to better understand and predict these physical phenomena and will hopefully guide further efforts to better characterize the effect of different heating systems in window condensation risk analysis., Peer reviewed, Peer reviewed article, Published.
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- Curcuminoids in turmeric roots and supplements
- Curcuma longa L. rhizomes are used extensively as a spice in food preparations and dietary supplements for their anti-inflammatory and antioxidant properties. An expert review panel (ERP) evaluated analytical methods for the quantitation of individual curcuminoids for the purpose of identifying a method for official method status. It was requested that several modifications be undertaken to improve method performance prior to subjecting the chosen method to a single-laboratory validation. Two separate Plackett-Burman factorial studies were used to identify factors that contributed to the chromatographic separation and extraction of curcuminoids. Significant factors were further optimized to produce the improved HPLC method for curcuminoid separation. This method was then subjected to a single-laboratory validation according to the AOAC International guidelines for linearity, detection limits, precision, and accuracy. The two most significant factors impacting the quantitation of curcuminoids were column temperature and extraction solvent, which were optimized to 55 °C and 100 % methanol, respectively. The validation was performed on 12 raw materials and finished products containing turmeric roots. The method precision was reported using HorRat values which were within recommended ranges of the AOAC guidelines. Overall accuracy of the method was accessed at three separate levels for each analyte and ranged from 99.3–100.9 %. The validated method is suitable for quantitation of individual curcuminoids in turmeric raw materials and finished products and is recommended for consideration as an official method by the AOAC International., Peer-reviewed article, Published. Received 13 July 2015; Accepted 21 September 2015; Published online 29 September 2015.
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- Current initiatives for the validation of analytical methods for botanicals
- The demand for validated analytical methods for botanicals has grown in response to the increasing consumer market for botanical supplements. Government initiatives to increase the availability of validated analytical methods and botanical reference material have led to the publication of numerous validation studies in scientific journals. Single laboratory validation and collaborative validation studies are structured to confirm a method's ruggedness and fit for purpose. The performance characteristics and statistical protocols followed throughout a validation study vary with the source of guidelines. Analytical techniques and priority methods are influenced by the need for fast-screening techniques, the limited availability of reference material, market value, and the prevalence of contaminants in botanical supplements., Peer-reviewed article, Published.
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- Current trends in brain-computer interface research at the Neil Squire foundation
- The Neil Squire Foundation (NSF) is a Canadian nonprofit organization whose purpose is to create opportunities for independence for individuals who have significant physical disabilities. Over the last ten years, our team in partnership with researchers at the Electrical and Computer Engineering Department, the University of British Columbia, has been working to develop a direct brain-controlled switch for individuals with significant physical disabilities. The NSF Brain Interface Project primarily focuses on the development of brain-computer interface switch technologies for intermittent (or asynchronous) control in natural environments. That is, technologies that will work when the user intends control but also remains in a stable off state when there is no intent to control. A prototype of such a switch has successfully been developed. This switch has demonstrated classification accuracies greater than 94%. The initial results are promising, but further research is required to improve switch accuracies and reliability and to test these switch technologies over a larger population of users and operating conditions. This paper provides an overview of the NSF brain-switch technologies and details our approach to future work in this area., Peer-reviewed article, Published. Manuscript received June 20, 2002; revised January 22, 2003.
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- Cyber-Security vulnerabilities: an impediment against further development of Smart Grid
- This chapter discusses anomalies which may not be attributed to expected operational deviations and/or mishaps associated with component failure and/or environmental conditions. The question here is: what are known cyber-security vulnerabilities which could be used to aid in the detection of patterns and signatures associated with various types of attacks and intrusions in the system which need to be detected and analyzed using Smart Grid's sensory data, such as Smart meter's and/or PMU's data, to help differentiate between "cyber-attacks in progress" as opposed to "expected system anomalies" due to operational failures of its components?, book chapter, published