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Climate change is driving worldwide shifts in the distribution of biodiversity, and fundamental changes to global avian migrations. Some arctic‐nesting species may shorten their migration distance as warmer temperatures allow them to winter closer to their high‐latitude breeding grounds. However, such decisions are not without risks, since this intensifies pressure on resources when they are used for greater periods of time. In this study, we used an individual‐based model to predict how future changes in food abundance, winter ice coverage, and human disturbance could impact an Arctic/sub‐Arctic breeding goose species, black brant (Branta bernicla nigricans, Lawrence 1846), and their primary food source, common eelgrass (Zostera marina L.), at the Izembek Lagoon complex in southwest Alaska. Brant use the site during fall and spring migrations, and increasingly, for the duration of winter. The model was validated by comparing predictions to empirical observations of proportion of geese surviving, proportion of geese emigrating, mean duration of stay, mean rate of mass gain/loss, percentage of time spent feeding, number of bird days, peak population numbers, and distribution across the complex. The model predicted that reductions >50% of the current decadal (2007–2015) mean of eelgrass biomass, which have been observed in some years, or increases in the number of brant, could lead to a reduction in the proportion of birds that successfully migrate to their breeding grounds from the site. The model also predicted that access to eelgrass in lagoons other than Izembek was critical for overwinter survival and spring migration of brant, if overall eelgrass biomass was 50% of the decadal mean biomass. Geese were typically predicted to be more vulnerable to environmental change during winter and spring, when eelgrass biomass is lower, and thermoregulatory costs for the geese are higher than in fall. We discuss the consequences of these predictions for goose population tr

The nature of rate controlling factors, whether thermodynamic or kinetic, has been under debate for fifty years. The arguments for both equilibrium and kinetic control are discussed using operating experience at Cominco and Broken Hill Associated Smelters (BHAS); it is maintained that the slag fuming process can approach thermodynamic equilibrium under industrial conditions and that this determines the ultimate limitation on its technical performance. Extrapolation of the equilibrium fuming model to a continuous fuming process predicts a severe reduction in average fuming rate and fuel efficiency compared with batch operation. Extrapolation of the kinetic model predicts no deterioration in fuming rate., The nature of rate controlling factors, whether thermodynamic or kinetic, has been under debate for fifty years. The arguments for both equilibrium and kinetic control are discussed using operating experience at Cominco and Broken Hill Associated Smelters (BHAS); it is maintained that the slag fuming process can approach thermodynamic equilibrium under industrial conditions and that this determines the ultimate limitation on its technical performance. Extrapolation of the equilibrium fuming model to a continuous fuming process predicts a severe reduction in average fuming rate and fuel efficiency compared with batch operation. Extrapolation of the kinetic model predicts no deterioration in fuming rate.

Pyrometallurgically produced zinc suffers from high lead and cadmium impurity contents; reflux distillation refining can produce special high-grade standard zinc, but at high costs. Previous published work on an alternative method, molten salt electrorefining of zinc metal, is critically reviewed. Recalculation of the estimated energy consumption for industrial-scale operation indicates that this is an order of magnitude lower than that of the reflux distillation method. Further laboratory and development work is required to establish the technical and commercial feasibility of the process., Pyrometallurgically produced zinc suffers from high lead and cadmium impurity contents; reflux distillation refining can produce special high-grade standard zinc, but at high costs. Previous published work on an alternative method, molten salt electrorefining of zinc metal, is critically reviewed. Recalculation of the estimated energy consumption for industrial-scale operation indicates that this is an order of magnitude lower than that of the reflux distillation method. Further laboratory and development work is required to establish the technical and commercial feasibility of the process.

Several new smelting technologies have emerged to challenge the production supremacy of the conventional sintering/blast furnace process. Although the new processes are all based on the same fundamental chemistry, the technical solutions to the several problems, together with the necessary compromises, need careful evaluation by the operator. In the refining field, there are some new developments, but there seems to be considerable potential for research arising from questioning of the perceived understanding of established processes., Several new smelting technologies have emerged to challenge the production supremacy of the conventional sintering/blast furnace process. Although the new processes are all based on the same fundamental chemistry, the technical solutions to the several problems, together with the necessary compromises, need careful evaluation by the operator. In the refining field, there are some new developments, but there seems to be considerable potential for research arising from questioning of the perceived understanding of established processes.

Climate change is driving worldwide shifts in the distribution of biodiversity, and fundamental changes to global avian migrations. Some arctic-nesting species may shorten their migration distance as warmer temperatures allow them to winter closer to their high-latitude breeding grounds. However, such decisions are not without risks, since this intensifies pressure on resources when they are used for greater periods of time. In this study, we used an individual-based model to predict how future changes in food abundance, winter ice coverage, and human disturbance could impact an Arctic/sub-Arctic breeding goose species, black brant (Branta bernicla nigricans, Lawrence 1846), and their primary food source, common eelgrass (Zostera marina L.), at the Izembek Lagoon complex in southwest Alaska. Brant use the site during fall and spring migrations, and increasingly, for the duration of winter. The model was validated by comparing predictions to empirical observations of proportion of geese surviving, proportion of geese emigrating, mean duration of stay, mean rate of mass gain/loss, percentage of time spent feeding, number of bird days, peak population numbers, and distribution across the complex. The model predicted that reductions >50% of the current decadal (2007–2015) mean of eelgrass biomass, which have been observed in some years, or increases in the number of brant, could lead to a reduction in the proportion of birds that successfully migrate to their breeding grounds from the site. The model also predicted that access to eelgrass in lagoons other than Izembek was critical for overwinter survival and spring migration of brant, if overall eelgrass biomass was 50% of the decadal mean biomass. Geese were typically predicted to be more vulnerable to environmental change during winter and spring, when eelgrass biomass is lower, and thermoregulatory costs for the geese are higher than in fall. We discuss the consequences of these predictions for goose population trend

Changes in climate, food abundance and disturbance from humans threaten the ability of species to successfully use stopover sites and migrate between non-breeding and breeding areas. To devise successful conservation strategies for migratory species we need to be able to predict how such changes will affect both individuals and populations. Such predictions should ideally be process-based, focusing on the mechanisms through which changes alter individual physiological state and behavior. In this study we use a process-based model to evaluate how Black Brant (Branta bernicla nigricans) foraging on common eelgrass (Zostera marina) at a stopover site (Humboldt Bay, USA), may be affected by changes in sea level, food abundance and disturbance. The model is individual-based, with empirically based parameters, and incorporates the immigration of birds into the site, tidal changes in availability of eelgrass, seasonal and depth-related changes in eelgrass biomass, foraging behavior and energetics of the birds, and their mass- dependent decisions to emigrate. The model is validated by comparing predictions to observations across a range of system properties including the time birds spent foraging, probability of birds emigrating, mean stopover duration, peak bird numbers, rates of mass gain and distribution of birds within the site: all 11 predictions were within 35% of the observed value, and 8 within 20%. The model predicted that the eelgrass within the site could potentially support up to five times as many birds as currently use the site. Future predictions indicated that the rate of mass gain and mean stopover duration were relatively insensitive to sea level rise over the next 100 years, primarily because eelgrass habitat could redistribute shoreward into intertidal mudflats within the site to compensate for higher sea levels. In contrast, the rate of mass gain and mean stopover duration were sensitive to changes in total eelgrass biomass and the percentage of time fo