91 research outputs found
Pilot bioreactors commission and operation at Minto Mine: 2014 & 2015 preliminary results
No full textFour (4) pilot anaerobic bioreactors were commissioned at the Minto mine site in the summer of 2014 by Amelie Janin, NSERC Industrial Research Chair at Yukon College, and Capstone staff. Installation was completed on August 7th, 2014 and operation started on August 20th, 2014. Bioreactor substrate composition varied among the bioreactors and included mixtures of creek sediments, low-grade or river gravel, wood chips or biochar (a coal made out of wood). During the first year the bioreactors were monitored until September 23rd, 2014, after which they were dismantled and stored for the winter. In the following year, the bioreactors resumed operation on June 2nd and were monitored between June 20th, 2015 and September 26th, 2015.Peer reviewedPublication is an outcome of the Bioremediation in Cold Climate project
Photochemical behavior of poly(organophosphazenes). Part XV Light-induced crosslinking of [(4-benzoylphenoxy)x(methoxy-ethoxy-ethoxy)2-x]phosphazene copolymers
No full texthe synthesis of a new, highly photosensitive, phosphazene copolymer containing an almost-equimolecular quantity of benzophenone and methoxyethoxyethoxy substituents is reported in this paper, together with the photochemical behavior of this material when irradiated in film both in oxygen and in an argon atmosphere. It has been detected that the photoreactivity of the phosphazene material strongly depends on the light absorption process by the benzophenone moieties, whose selective excitation predominantly brings about an intramolecular hydrogen abstraction reaction from the ethylene oxide units, thus producing highly reactive phosphazene macroradicals. The coupling reactions of these species results in the complete cross-linking of the polyphosphazene substrate and in its total insolubilization. Moreover, the influence of molecular oxygen on the overall photochemical process of the benzophenone/ethyleneoxide-substituted phosphazene copolymer is investigated. The implications of the light-induced reticulation process in the controlled insolubilization of poly[bis(methoxyethoxyethoxy)phosphazene] are also discussed
A survey of bird use of the wetlands of the Tatchun-to-Minto Yukon Valley
No full text"The 48-km stretch of the Yukon Valley from the mouth of Tatchun Creek to Minto Crossing was surveyed. 110 islands, just over 50 back channels, plus 14 off-channel ponds constitute the wetland habitat most used by birds. Two key areas were groupings of islands and mid-channel bars, one near Yukon Crossing and one near the mouth of McCabe creek. We found 31 species of water birds using the area. Vegetation on river bars and islands was key. In constant successional stage, riparian willow bordered by a grass
and sedge community with horsetail as the key emergent was used principally by migrating waterfowl. Breeding by waterfowl was a minor use, (5 species). A relatively dense assemblage of birds of prey indicate a highly productive area: 6 pairs of Bald eagles and 3 pairs of peregrine falcons were recorded. The inordinate mix of islands and cut off channels in the region with its obvious use by spawning salmon are key to the reason the area has such high local value. Moose, wolves, bears and a variety of small mammals along with 95 species of birds were found using the habitats of this river reach. Protecting the ecology of the area will involve maintaining the current hydrologic regime, protecting critical habitats from disturbance and avoiding contaminating the key back channels and inflow streams."--from Summary
Definition of a tolerable upper intake level of niacin: a systematic review and meta-analysis of the dose-dependent effects of nicotinamide and nicotinic acid supplementation
No full textContext: Nicotinic acid and nicotinamide are soluble compounds of the vitamin B group, widely used to regulate the lipid profile in hyperlipidemic individuals. Higher doses of nicotinic acid are associated with adverse effects, especially flushing. A unique tolerable upper intake level (UL) of nicotinic acid has not been defined.
Objective: This meta-analysis aims to evaluate adverse effects and their incidence after supplementation with different doses of nicotinic acid and nicotinamide, comparing results with current ULs in Europe and the United States.
Data Sources: PubMed was searched for articles providing detailed information about nicotinic acid or nicotinamide supplementation and related outcomes.
Study Selection: A total of 2670 citations were selected for screening. Two primary outcomes were considered: occurrence of adverse effects following nicotinic acid or nicotinamide supplementation, and dose at which adverse effects occurred.
Data extraction: Details on study population, type and duration of treatment, dosage of vitamins, association with lipid-influencing drugs, length of follow-up, and incidence and type of adverse events were extracted.
Results: After screening, 47 articles involving 11 741 individuals were included. Meta-analysis was based on estimation of benchmark doses for the probability of adverse effects after supplementation. In individuals with dyslipidemia or cardiovascular disease, nicotinic acid monotherapy seems to be protective against any adverse effects considered, as adverse events occurred at doses above those used with other treatments. In healthy individuals treated with nicotinic acid alone, major adverse effects occurred at doses below 1000 mg/d.
Conclusions: Results may indicate a high degree of conservativeness in the UL of nicotinic acid, fixed at 35 mg/d in United States and 10 mg/d in Europe. Reconsideration of the UL of nicotinic acid for nutritional supplements, possibly differentiating between ULs in healthy and unhealthy individuals, may be warranted. © The Author(s) 2017. Published by Oxford University Press on behalf of the International Life Sciences Institute. All rights reserved. For Permissions, please e-mail: [email protected]
Risk Assessment of Induced Currents and Voltages Under Maintenance Conditions Supported by Measurement Campaigns on HV/EHV OHLs
No full textThis paper deals with the risk assessment and the procedure to be followed to plan the maintenance interventions on HV/EHV overhead lines (OHLs). The possible occurrence of induced current and voltage phenomena, due to the proximity with other power lines, makes the procedure for maintenance intervention more rigorous. The maintenance protocol is also supported by the results of a measurement campaign carried out on a 380 kV double-circuit OHL of the Italian Transmission Grid, with the aim of evaluating the induced voltages and currents on one circuit, under maintenance, due to the normal operation of the second one in parallel
Experimental Validation of Multiconductor Cell Analysis by Overhead Line Field Measurements
No full textMulticonductor Cell Analysis (MCA) is a matrix algorithm computing the electrical steady-state regime of any asymmetrical multiconductor system. This paper presents an experimental validation of MCA, which is carried out by a measurement campaign performed on the Extra High Voltage (EHV) Dolo-Venezia Nord 18 km long double-circuit OverHead Line (OHL). By considering the double-circuit configuration of this line, it has been assessed the impact of one inducing circuit, kept in service, on the other circuit, kept out of service, for the evaluation of induced voltages and currents. One more time, comparisons between computations and measurements confirm the good agreement between MCA and the physical behavior of multiconductor systems
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