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Caswell H.C.,Pacific Power | Forte V.J.,National Grid | Fraser J.C.,Nova Scotia Power Inc. | Pahwa A.,Kansas State University | And 3 more authors.
IEEE Transactions on Power Delivery | Year: 2011

Weather significantly influences distribution reliability indices, especially duration benchmarks like SAIDI. We explore correlations with various weather parameters including lightning-detection network data, and wind from weather stations. This paper explores a number of ways to account for the variability caused by weather. Approaches include regression models to normalize with weather data as inputs, using outage database indicators of weather, and modifications to the 2.5 beta method of IEEE Std. 1366. © 2010 IEEE.


Han Y.,Nova Scotia Power Inc. | Chang L.,University of New Brunswick
2nd International Symposium on Power Electronics for Distributed Generation Systems, PEDG 2010 | Year: 2010

This paper discusses the accuracy of the prediction of aggregated wind power of planned wind farms distributed in the Maritime Canada. Especially this study calculates and analyzes the aggregated regional wind power forecast error compared to single sites. Using simulated measured wind power and expected wind power from 5 planned wind farms, this research finds that the reduction of the ensemble wind power forecast error depends on the size of the region. To generate these findings, the spatial correlation function of prediction error is applied to calculate the ensemble wind forecast error based on arbitrary configurations of wind farms and wind generations, as long as the total installed wind capacity is a fixed number for selected planned wind farms. The validation of the spatial smoothing effects will provide the Maritime utilities an alternative method to reduce the regional aggregated wind power forecast errors instead of using costly wind prediction system. © 2010 IEEE.


Zheng K.,North China Electrical Power University | Boteler D.,Natural Resources Canada | Pirjola R.J.,Natural Resources Canada | Liu L.-G.,North China Electrical Power University | And 4 more authors.
IEEE Transactions on Power Delivery | Year: 2014

The geomagnetically induced currents (GICs) produced in power systems during magnetic storms are a function of the electric-field amplitude and direction, and the characteristics of the power system. This paper examines the influence of a number of power system characteristics, which include the resistances and structures of the conductors; the length of the transmission lines; the number, type, and resistances of transformers, the substation grounding resistances, and the topology of the network. It is shown that GIC grows with increasing line length but approaches an asymptotic constant value, and a more relevant parameter than the individual line length is the length of the entire system. This paper also derives the effective GIC for a conventional transformer and an autotransformer, and analyzes the behavior of GIC when the network topology changes illustrated with the GIC-Benchmark Model. The results of these studies provide a guide to estimating GIC impacts on a power network. © 1986-2012 IEEE.


Watson R.,Dalhousie University | Castleden H.,Dalhousie University | Partnership T.,Nova Scotia Power Inc. | Masuda J.,University of Manitoba | And 2 more authors.
Preventing Chronic Disease | Year: 2012

Introduction: Asthma is the most common chronic condition affecting Aboriginal youth aged 8 to 12 years in Canada. Research investigating psychosocial challenges associated with asthma is limited. This study examines support resources, support-seeking strategies, support and education needs, and intervention preferences of Aboriginal youth with asthma and their caregivers in an effort to encourage community-wide, health-promoting behaviors. Methods: We employed a community-based participatory research design to conduct interviews with 21 youths aged 8 to 12 years and 17 caregivers from 5 Mi'kmaq communities in Unama'ki (Cape Breton) Nova Scotia, Canada. After conducting interviews that explored existing and desired social, educational, and health support in participating communities, we held a 2-day asthma camp to engage participants in asthma education, social support networking, and cultural activities. At the camp, we collected data through participant observation, sharing circles, focus groups, and youth drawings of their experiences living with asthma. Results: Our study yielded 4 key findings: 1) asthma triggers included household mold, indoor smoking, pets, season change, strenuous exercise, extreme cold, and humidity; 2) social and educational support is lacking in Mi'kmaq communities despite a strong desire for these services; 3) cultural, linguistic, and geographic barriers to accessing support exist; and 4) family members are primary support resources. Conclusion: Improved support and educational resources are needed to foster effective Mi'kmaq asthma support networks. Future asthma interventions for marginalized populations must be culturally meaningful and linguistically accessible to those using and providing asthma support.


Fenton G.A.,Dalhousie University | Sutherland N.,Nova Scotia Power Inc.
IEEE Transactions on Power Delivery | Year: 2011

It is well known that environmental loads, e.g., wind and ice, acting on power transmission lines are highly uncertain, as are the structural strengths of the towers supporting the lines. The design of such systems must take uncertainty into account in order to achieve acceptable reliability at a reasonable cost. The paper presents a simulation-based methodology for the optimal design of a transmission line which considers uncertainties in both environmental loads and structural resistance. The methodology is developed and illustrated for the simple problem of determining the optimal span length required for designing against tower failure. Wind, ice, and tower resistances are simulated over the extent of the transmission line and over the design life of the transmission system. Total expected system cost, along with the estimated probability of lifetime failure, are produced for a range of possible span lengths, allowing an informed decision regarding the optimum span length for the tower strength limit state. © 2010 IEEE.


Vercaemer B.,Bedford Institute of Oceanography | Sephton D.,Bedford Institute of Oceanography | Nicolas J.M.,Nova Scotia Power Inc. | Howes S.,Bedford Institute of Oceanography | Keays J.,Canadian Coast Guard
Aquatic Invasions | Year: 2011

Life history processes, such as reproduction, survival and growth, are known to be strongly affected in ascidians by different types of environmental factors including temperature and salinity. In a field study conducted from 2005 to 2009 in southern Nova Scotia, an area affected by invasions of Ciona intestinalis, low winter and high summer temperatures were shown to be strongly associated with intra- and inter- annual variation in larval recruitment. No clear patterns of association were seen with other environmental variables such as chlorophyll and indices of nutrient concentrations. In a 12 week challenge experiment in the laboratory, survival and growth of juvenile C. intestinalis were affected by both salinity and temperature. Individuals exposed to high temperature (25°C) and low salinity (20) did not survive the sustained exposure. In addition, Individual Specific Growth Rates were shown to decrease as salinity decreased. Temperature and salinity are factors which will subsequently influence distribution, persistence and potential for spread of adult populations. New favourable temperature and salinity conditions (e.g., potentially resulting from global climate change) will likely alter the distribution patterns of C. intestinalis. Conversely, infestation management techniques or site selection could benefit from unfavourable sustained temperature and salinity conditions.© 2011 REABIC.


Sephton D.,Bedford Institute of Oceanography | Vercaemer B.,Bedford Institute of Oceanography | Nicolas J.M.,Nova Scotia Power Inc. | Keays J.,Canadian Coast Guard
Aquatic Invasions | Year: 2011

The shellfish culture industry in Atlantic Canada has been adversely affected by the presence of non-indigenous, invasive tunicates since the mid-1990's. A Fisheries and Oceans Canada Aquatic Invasive Species (DFO-AIS) monitoring program documented the presence, establishment, and spread of five tunicate species at geo-referenced coastal monitoring stations in Nova Scotian waters from 2006-2009. Styela clava (Herdman, 1881) and Didemnum vexillum (Kott, 2002) were not found in Nova Scotia during the course of this study, despite their problematic presence in Prince Edward Island and the Gulf of Maine, respectively. Botryllus schlosseri (Pallas, 1766) was the most widely distributed species, found at more than 69% of sites monitored in all years. Ciona intestinalis (Linnaeus, 1767) was present at about half of the stations in all years, and while its populations were heaviest and most persistent in the Halifax - St. Margaret's Bay, Shelburne - Port La Tour, and Canso - Isle Madame areas, there was evidence of spread on the eastern and Fundy shores, and in Cape Breton. Botrylloides violaceus (Oka, 1927), was the least common tunicate encountered, but its distribution increased from 19% of stations in 2006 to 50% of stations in 2009. Tunicates occupied a wide variety of hard substrates (natural and artificial) in waters with 13.0 to 33.2 salinity and at oxygen saturations of 32.5 to 124.8%. © 2011 REABIC.


Gao H.,CANMET Energy | Runstedtler A.,CANMET Energy | Majeski A.,CANMET Energy | Boisvert P.,CANMET Energy | Campbell D.,Nova Scotia Power Inc.
Biomass and Bioenergy | Year: 2016

A computational fluid dynamics (CFD) tool, CFX-TASCflow, with a drag force sub-model for woodchip particles was used to explore the optimization of woodchip co-firing of a Canadian utility boiler, after it was first validated by comparing the model results with field operation data when firing Colombia coal. The CFD model predicted both a small increase in NO emissions and a significant increase in unburned carbon in fly ash for the originally proposed co-firing configuration, with 85% of the unburned carbon originating from the woodchips. Improvement strategies were examined, including intensifying the swirl inside the furnace to improve oxygen availability for woodchip combustion, lowering the woodchip injection level to increase residence time, and reducing woodchip particle size to shorten burnout time. The model results revealed the importance of intensified swirl on the burnout of large woodchip particles and the sensitivity of NO emissions to the air distribution in the combustion zone. Also, the model predicted an increase in large unburned woodchip particles falling into the bottom hopper when lowering woodchip injection level, although there was an overall improvement in predicted woodchip burnout. An improvement in woodchip burnout was also observed with reduced woodchip particle size. Based on these results, a co-firing strategy is suggested that is predicted to give reasonable burnout and NOx emissions at a minimum retrofitting cost. Crown Copyright © 2016 Published by Elsevier Ltd. All rights reserved.


Clements B.R.,CANMET Energy | Zhuang Q.,CANMET Energy | Pomalis R.,CANMET Energy | Wong J.,CANMET Energy | Campbell D.,Nova Scotia Power Inc.
Fuel | Year: 2012

This study addresses ignition characteristics encountered when co-firing petroleum coke with coal and provides insight into addressing ignition problems that may occur. A pilot-scale test procedure is proposed to determine lean ignition limits and experimental results are presented. Experimental data is presented for various co-fired mixtures of petroleum coke with coal. Qualitative discussions that relate the lean ignition limit to the volatile matter and aerodynamic conditions are presented. The study extends these results to the development of a full-scale pulverized fuel steam generation unit operating procedure that has been successfully implemented within a power generation utility. The lean ignition limit is reached between 62% and 67% petroleum coke for swirl numbers of 0.35 and 0.40, respectively. Although a burner aerodynamic effect exists, it seems relatively small compared with the influence of the amount of overall volatile matter. The total volatile matter in the co-firing case was between 19.9% and 21.0% at the time of flame extinction for the two different aerodynamic conditions tested. Full-scale operating conditions had been limited to 20% petroleum coke prior to this study. This study confirmed that this level of operation was acceptable and far below where ignition problems are expected during full-scale operation. This conservative approach is well justified because it must account for extreme conditions that may be experienced during operational upset conditions.


PubMed | Nova Scotia Power Inc.
Type: Journal Article | Journal: The Journal of frailty & aging | Year: 2016

Frailty is a state of increasing vulnerability that places an individual at high risk for adverse health outcomes. The best approach for frailty measurement in clinical practice has not been resolved. Frailty can be measured by deficit accumulation and be derived from a comprehensive geriatric assessment (CGA). In busy clinical practice, it may not be feasible to gather this information entirely from patients, particularly from those with cognitive decline.We describe the feasibility of a frailty index based upon a care partner derived CGA (CP-CGA). In addition, we sought to establish the acceptability of the questionnaire and explore whether care partners felt that the provided information contribute to patient assessment.A cross-sectional data analysis of 99 community dwelling older adults attending geriatric ambulatory care clinics at a single tertiary care center.Care partners completed the CP-CGA and a Clinical Frailty Scale (CFS; Range 1 -Very fit- to 9 -Terminally ill). We evaluated the time to complete and item completeness.The mean age of patients was 81.35.7 years. Most were women (n=54), widowed, lived in their own home, with a median CFS of 5 (Mildly Frail). The care partner respondent was usually an offspring. Item completeness was 95% with a mean time to complete of 15.58.6 minutes.The CP-CGA seems feasible for gathering information that would be integral towards determining frailty by deficit accumulation. Future inquiries will evaluate its feasibility in other settings and validity as a form of frailty assessment.

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