Gypsy moth (Lymantria dispar L.) is one of the world's worst hardwood defoliating invasive alien species. It is currently spreading across North America, damaging forest ecosystems and posing a ...significant economic threat. Two subspecies L. d. asiatica and L. d. japonica, collectively referred to as Asian gypsy moth (AGM) are of special concern as they have traits that make them better invaders than their European counterpart (e.g. flight capability of females). We assessed the potential distribution of AGM in Canada using two presence-only species distribution models, Maximum Entropy (MaxEnt) and Genetic Algorithm for Rule-set Prediction (GARP). In addition, we mapped AGM potential future distribution under two climate change scenarios (A1B and A2) while implementing dispersal constraints using the cellular automation model MigClim. MaxEnt had higher AUC, pAUC and sensitivity scores (0.82/1.40/1.00) when compared to GARP (0.70/1.26/0.9), indicating better discrimination of suitable versus unsuitable areas for AGM. The models indicated that suitable conditions for AGM were present in the provinces of British Columbia, Ontario, Quebec, Nova Scotia and New Brunswick. The human influence index was the variable found to contribute the most in predicting the distribution of AGM. These model results can be used to identify areas at risk for this pest, to inform strategic and tactical pest management decisions.
Brochet is a remote, off-grid community located in Northern Manitoba, Canada. The existing diesel generating system is characterized by high economic and environmental cost. As the existing diesel ...generators are nearing their operational lifespan, this study uses the HOMER model to determine an optimum electricity system design at Brochet that has high electrical reliability, least cost, and low emissions. Two potential power generation options based on reduced sized diesel generator, and a wind–diesel hybrid system were evaluated and compared against the existing diesel-based electricity system at Brochet. The wind–diesel hybrid system performed best in all three (i.e. electrical, economics, and environmental) evaluation criteria. While maintaining high reliability, this hybrid system design resulted in 30% reduction in cost of electricity produced, and 18% reduction of carbon dioxide emissions when compared to the existing electricity system at Brochet. Thus, this study concludes that the wind–diesel hybrid system is the optimum electricity system design for Brochet and proposes this system to replace the existing system.
The reuse of mining waste-rocks as construction material constitutes an innovative management approach consistent with the principles of sustainable development. Nevertheless, the implementation of ...this approach is still limited by most guidelines due principally to insufficient knowledge of these materials performances and to unjustified presumptions related to their chemical instability (presence of sulfide). This paper approaches these issues by assessing the reuse potential of low-sulfide mining waste-rocks as aggregates for concrete regarding to the Quebec (Canada) recycling guidelines of non-hazardous inorganic wastes as construction materials. Toxicity characteristic leaching procedure (TCLP), comprehensive physical, chemical (XRF and ICP-AES) and mineralogical investigations (XRD and SEM) as well as modern automated mineral liberation analyses have been carried out. In addition, UCS results of various concrete mixtures using different binders were then presented to illustrate the reuse potential of the waste-rocks. The TCLP test showed the nonhazardous character of the waste rocks. They contained low sulfide content (0.5 wt%), which classify them as non-acid generating and able to meet the classification in recycling category including concrete production. Moreover, liberation analyses showed that most sulfides are concentrated in the fine fraction as pyrite occurrence with a liberated fraction of only 2%. These results influenced significantly the properties of the resulting concretes, which presented good mechanical performances especially when coarse waste rock above 20 mm and fine one below 80 μm was removed.
•TCLP test showed that waste rocks is a non-hazardous material.•Grain size distribution of coarse waste rocks fraction was similar to reference gravels used for concretes production.•Total sulfur content of waste rocks was not exceeding 0.5 wt%, classifying the material as non-acid generating.•Iron sulfides (mainly of pyrite) are almost encapsuled within gangue mineral. Only 2% of pyrite is free.•Natural sand instead of the waste rocks fine fraction improve the concrete strength.
Sponsored by the U.S. Department of Homeland Security Science & Technology (DHS S&T) Chemical Security Analysis Center (CSAC), the U.S. Department of Defense (DoD) Defense Threat Reduction Agency ...(DTRA), Transport Canada, and Defence Research and Development Canada (DRDC), the Jack Rabbit II tests were designed to release liquid chlorine at ambient temperature in quantities of 5–20 T for the purpose of quantifying the behavior and hazards of catastrophic chlorine releases at scales represented by rail and truck transport vessels. In 2015, five successful field trials were conducted in which chlorine was released in quantities of 5–10 tons through a 6-inch circular breach in the tank and directed vertically downward at 1 m elevation over a concrete pad. In 2016, three additional trials were conducted with releases of 10 tons also through 6-inch circular breaches at different release orientations. A final 20 ton test was conducted in 2016. Data from the test program is available. This paper summarizes an analysis of the available data from the concrete pad including analysis of the temperature measurements above and below grade in the concrete pad. Assessment of the chlorine rainout is estimated based on temperature measurements and available video data analysis.
•The Jack Rabbit II tests were designed to release liquid chlorine at ambient temperature in quantities of 5–20 T for the purpose of quantifying the behavior and hazards of catastrophic chlorine releases at scales represented by rail and truck transport vessels.•This paper summarizes an analysis of the available data from the underlying concrete pad including analysis of the temperature measurements above and below grade in the concrete pad.•Assessment of the chlorine rainout is estimated based on temperature measurements and available video data analysis.
•A methodology for a semi-automated pedestrian-cyclist conflict analysis is proposed.•Cyclist speed, pedestrian density, conflict severity and conflict types are related.•The relationship between ...conflict rate and pedestrian density depends on cyclist speed.•Conflict type, based on intersecting angle and road user configuration, impacts safety.
In the past decade, transportation planners worldwide have been incorporating shared space design elements as a way of creating pedestrian-friendly places. Streets incorporating shared-space principles tend to have reduced vehicle speeds and increased safety for vulnerable road users. In North American cities, a shared-space approach is rarely applied to non-motorized environments such as pedestrian malls, campuses, and parks. As cyclists and pedestrians travel at relatively slow speeds, there is an opportunity to provide safe infrastructure to both through non-motorized shared spaces. Yet, little empirical evidence exists concerning the risk of pedestrian-cyclist collisions in shared spaces. Existing surrogate methods are either difficult to automate or insufficient to describe interactions between vulnerable users. To address this research gap, a methodological framework is proposed based on the analysis of semi-automated pedestrian-cyclist interactions and the integration of surrogate methods in non-motorized shared space. Several proposed surrogate safety measures (SSMs) including cyclist speed, angle of approach, pedestrian density, and post-encroachment time are analysed to estimate the risk of pedestrian-cyclist interactions. The methodology is then applied to a case study on the McGill University campus in Montreal, Canada, where cyclists and pedestrians coexist. User trajectories are automatically extracted using a computer vision software to yield 2739 pedestrian-cyclist interactions for analysis. The derived SSMs demonstrate adequate levels of safety. For example, speed and pedestrian density are shown to be negatively correlated, while conflict rate and density are positively correlated. Statistical differences are shown between conflict types defined based on intersecting angle and road user configuration.
We analyze the introduction of highly subsidized, universally accessible child care in Quebec, addressing the impact on child care utilization, maternal labor supply, and family well‐being. We find ...strong evidence of a shift into new child care use, although some crowding out of existing arrangements is evident. Maternal labor supply increases significantly. Finally, the evidence suggests that children are worse off by measures ranging from aggression to motor and social skills to illness. We also uncover evidence that the new child care program led to more hostile, less consistent parenting, worse parental health, and lower‐quality parental relationships.
Numerous reservoirs around the world provide multiple flow regulation functions; key among these are hydroelectricity production and water releases for irrigation. These functions contribute to ...energy and food security at national, regional and global levels. While reservoir operations for hydroelectricity production might support irrigation, there are also well-known cases where hydroelectricity production reduces water availability for irrigated food production. This study assesses these relationships at the global level using machine-learning techniques and multi-source datasets. We find that 54% of global installed hydropower capacity (around 507 thousand Megawatt) competes with irrigation. Regions where such competition exists include the Central United States, northern Europe, India, Central Asia and Oceania. On the other hand, 8% of global installed hydropower capacity (around 79 thousand Megawatt) complements irrigation, particularly in the Yellow and Yangtze River Basins of China, the East and West Coasts of the United States and most river basins of Southeast Asia, Canada and Russia. No significant relationship is found for the rest of the world. We further analyze the impact of climate variables on the relationships between hydropower and irrigation. Reservoir flood control functions that operate under increased precipitation levels appear to constrain hydroelectricity production in various river basins of the United States, South China and most basins in Europe and Oceania. On the other hand, increased reservoir evaporative losses and higher irrigation requirements due to higher potential evaporation levels may lead to increased tradeoffs between irrigation and hydropower due to reduced water availability in regions with warmer climates, such as India, South China, and the Southern United States. With most reservoirs today being built for multiple purposes, it is important for policymakers to understand and plan for growing tradeoffs between key functions. This will be particularly important as climate mitigation calls for an increase in renewable energy while agro-hydrological impacts of climate change, population and economic growth and associated dietary change increase the need for irrigated food production in many regions round the world.
•TRNSYS models of six energy-efficient housing archetypes are developed.•BIPV-T systems always produce more useful energy than a BIPV system.•The break-even cost of BIPV-T compared to BIPV can be up ...to 2700CAD.•The break-even cost of BIPV‑T is around 4200CAD compared to a PV+T system.•It is estimated at 6400CAD for a price of BIPV 10% lower than PV.
The market share of building-integrated photovoltaics (BIPV) remains limited. One of the main barriers to its larger adoption is its initial capital cost, as BIPV is generally more expensive than traditional roof or façade mounted photovoltaic modules (PV). Converting BIPV systems into BIPV with thermal energy recovery (BIPV-T) can improve its benefit and competitiveness compared to other solar energy technologies. This benefit is difficult to estimate, however, as it strongly depends on the usefulness of the thermal energy produced and the incremental cost of the technology to recover the heat. This study aims at evaluating the cost-benefit of BIPV-T focusing on systems that use air as the heat recovery fluid and are integrated into all-electric energy-efficient homes located in heating dominated climates. This cost-benefit is evaluated using the concept of break-even cost defined as the maximum incremental cost to convert a BIPV system into a BIPV-T system to break-even with the cost of (a) a BIPV system and (b) side-by-side PV modules and solar thermal collectors (PV+T). To obtain this cost, the useful equivalent energy production of BIPV, BIPV-T and PV+T systems was first obtained for six energy-efficient housing archetypes located in various cities across Canada. Four different heat management scenarios were considered for the BIPV-T system: (1) fresh air preheating, (2) domestic hot water preheating through an air-to-water heat exchanger, (3) domestic hot water and space heating with an air-to-water heat pump and (4) domestic hot water heating (DHW) with a heat pump water heater. Compared to BIPV, BIPV-T systems always produce more useful energy and as a result, the break-even cost compared to a BIPV system was found to be always positive and up to 2700CAD for a medium 2-storey home located in Montreal. For that same house and considering the price of BIPV equal to that of standard roof-mounted PV modules, the break-even cost of a BIPVT system compared to a PV+T system was estimated at 4200CAD. If the price of BIPV were to get 10% lower than PV, however, this break-even cost could increase to 6400CAD.
The Atlantic mackerel (Scomber scombrus) in the Northwest Atlantic is comprised of northern and southern components that have distinct spawning sites off Canada (northern contingent) and the US ...(southern contingent), and seasonally overlap in US fished regions. Thus, assessment and management of this population can be sensitive to levels of mixing between contingents, which remain unknown. Multi-decadal trends in contingent mixing levels within the US fisheries region were assessed, and the contingent composition across seasons, locations, ages, and size classes were characterized using archived otoliths and developing a classification baseline based on juvenile otolith carbon and oxygen stable isotopes (δ
C/δ
O values). Classification of age ≥ 2 adults demonstrated that northern contingent mixing was prevalent within the US continental shelf waters during the past 2 decades (2000-2019), providing an important seasonal subsidy to the US winter fishery despite substantial depletion in spawning stock biomass of the dominant northern contingent. While the majority of older fish were of the northern contingent during the early 2000s, the southern contingent contribution increased with age/size class during the recent period (2013-2019). Spatial mixing was most prevalent during February and March when the northern contingent occurred as far south as the Delmarva Peninsula, but were mostly absent from US waters in May. A positive relationship (albeit not significant; r = 0.60, p = 0.07) occurred between northern contingent mixing and US fisheries landings, which could imply that higher contingent mixing levels might be associated with greater landings for the US winter mackerel fishery. The yield of the Northwest Atlantic mackerel depends upon the status of the northern contingent, with the southern contingent possibly more prone to depletion. Spatially explicit stock assessment models are recommended to conserve both productivity and stability in this two-component population.
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