598 research outputs found
DOs and DON'Ts for using climate change information for water resource planning and management: guidelines for study design
Water managers are actively incorporating climate change information into their long- and short-term planning processes. This is generally seen as a step in the right direction because it supplements traditional methods, providing new insights that can help in planning for a non-stationary climate. However, the continuous evolution of climate change information can make it challenging to use available information appropriately. Advice on how to use the information is not always straightforward and typically requires extended dialogue between information producers and users, which is not always feasible. To help navigate better the ever-changing climate science landscape, this review is organized as a set of nine guidelines for water managers and planners that highlight better practices for incorporating climate change information into water resource planning and management. Each DOs and DON'Ts recommendation is given with context on why certain strategies are preferable and addresses frequently asked questions by exploring past studies and documents that provide guidance, including real-world examples mainly, though not exclusively, from the United States. This paper is intended to provide a foundation that can expand through continued dialogue within and between the climate science and application communities worldwide, a two-way information sharing that can increase the actionable nature of the information produced and promote greater utility and appropriate use
End point determination for spent nuclear fuel drying operations
When spent nuclear fuel is being dried ahead of either interim storage or long term disposal it is necessary to be able to confirm that the required level of dryness has been achieved. This has typically involved a vacuum rebound test however this method has certain limitations in terms of both reliability of the result and also by introducing an additional step that is time consuming and depending on the drying system used requires additional equipment at high system cost. It would be preferable if the end point and requisite dryness could be confirmed from online data readings recorded during the drying process. This paper presents the results of a number of vacuum drying tests using a benchtop drying rig in which online dew point, temperature, pressure and mass flow rate readings were compared to the results of vacuum rebound tests. Mass flow rate, pressure and dew point readings all showed cliff edge behaviour as the drying process progressed. Flow rate provided a good indicator of progress however it was clear from the behaviour that the resolution of the instrument was not sufficient to confirm dryness. Neither pressure nor dew point readings alone were capable of indicating whether a test would be passed successfully however it was found that in combination an envelope existed in which a vacuum rebound test was always passed. Testing of the same techniques for flowed gas drying methods was limited due to the lack of a suitable way of confirming whether dryness was achieved however there was an indication that dew point measurements would be capable of confirming that a set level of dryness had been achieved
Methane emissions from oil and gas transport facilities – exploring innovative ways to mitigate environmental consequences
Allergic sensitization: screening methods
Experimental in silico, in vitro, and rodent models for screening and predicting protein sensitizing potential are discussed, including whether there is evidence of new sensitizations and allergies since the introduction of genetically modified crops in 1996, the importance of linear versus conformational epitopes, and protein families that become allergens. Some common challenges for predicting protein sensitization are addressed: (a) exposure routes; (b) frequency and dose of exposure; (c) dose-response relationships; (d) role of digestion, food processing, and the food matrix; (e) role of infection; (f) role of the gut microbiota; (g) influence of the structure and physicochemical properties of the protein; and (h) the genetic background and physiology of consumers. The consensus view is that sensitization screening models are not yet validated to definitively predict the de novo sensitizing potential of a novel protein. However, they would be extremely useful in the discovery and research phases of understanding the mechanisms of food allergy development, and may prove fruitful to provide information regarding potential allergenicity risk assessment of future products on a case by case basis. These data and findings were presented at a 2012 international symposium in Prague organized by the Protein Allergenicity Technical Committee of the International Life Sciences Institute’s Health and Environmental Sciences Institute
Scientific Opinion on the safety and efficacy of iron compounds (E1) as feed additives for all species: Ferrous sulphate monohydrate based on a dossier submitted by Kronos International, Inc.
Ferrous sulphate monohydrate is safe when supplied up to a maximum iron content per kilogram complete feedingstuff of 450 mg for bovines and poultry, 500 mg for ovines, 600 mg for pets, and 750 mg for other species/categories, except horses and fish; for piglets up to one week before weaning a maximum of 250 mg Fe/day is considered safe. Because of insufficient data on horses and fish, as a provisional measure, the current value (750 mg Fe/kg) could be maintained. The values for total dietary iron for pigs, ovines, horses, fish and other species/categories (except poultry, bovines and pets) are in line with those currently authorised. Iron from ferrous sulphate monohydrate is unlikely to modify the iron concentration in edible tissues and products of animal origin. Consumer exposure in the EU is not associated with a risk of excess iron intake to the general population. Therefore, the FEEDAP Panel does not foresee any concern for consumer safety resulting from the use of ferrous sulphate monohydrate in animal nutrition, provided that the maximum iron content in complete feedingstuffs is respected. Ferrous sulphate monohydrate is irritant and corrosive to the skin, eyes and respiratory tract. The additive contains up to 109 mg Ni/kg. Nickel is a dermal and respiratory sensitiser, and inhalation may cause lung cancer. Thus, handling the additive poses a risk to the user/worker. Considering the high concentration of iron and sulphur in soil and water, the supplementation of feed with the additive is not expected to pose an environmental risk. Ferrous sulphate monohydrate is an effective iron source for all animal species and categories. The FEEDAP Panel recommends that the currently authorised maximum iron content in complete feed be reduced for bovines and poultry from 750 to 450 mg Fe/kg, and for pets from 1250 to 600 mg Fe/kg
Coupled biogeochemical cycles : eutrophication and hypoxia in temperate estuaries and coastal marine ecosystems
Author Posting. © Ecological Society of America, 2011. This article is posted here by permission of Ecological Society of America for personal use, not for redistribution. The definitive version was published in Frontiers in Ecology and the Environment 9 (2011): 18–26, doi:10.1890/100008.Nutrient fluxes to coastal areas have risen in recent decades, leading to widespread hypoxia and other ecological damage, particularly from nitrogen (N). Several factors make N more limiting in estuaries and coastal waters than in lakes: desorption (release) of phosphorus (P) bound to clay as salinity increases, lack of planktonic N fixation in most coastal ecosystems, and flux of relatively P-rich, N-poor waters from coastal oceans into estuaries. During eutrophication, biogeochemical feedbacks further increase the supply of N and P, but decrease availability of silica – conditions that can favor the formation and persistence of harmful algal blooms. Given sufficient N inputs, estuaries and coastal marine ecosystems can be driven to P limitation. This switch contributes to greater far-field N pollution; that is, the N moves further and contributes to eutrophication at greater distances. The physical oceanography (extent of stratification, residence time, and so forth) of coastal systems determines their sensitivity to hypoxia, and recent changes in physics have made some ecosystems more sensitive to hypoxia. Coastal hypoxia contributes to ocean acidification, which harms calcifying organisms such as mollusks and some crustaceans.Funding
was supplied in part by NOAA through the Coastal
Hypoxia Research Program, by the NSF through the
Biocomplexity Coupled Biogeochemical Cycles competition,
and by DR Atkinson through an endowment given
to Cornell University
Structural Stability Analysis of Waste Packages Containing Low- and Intermediate-Level Radioactive Waste in a Silo-type Repository
The structural stability of a waste package is essential for containing radioactive waste for the long term in a repository. A silo-type disposal facility would require more severe verification for the structural integrity, because of radioactive waste packages staked with several tens of meters and overburdens of crushed rocks and shotcretes. In this study, structural safety was analyzed for a silo-type repository, located approximately 100 m below sea level in Gyeongju, Korea. Finite element simulation was per -formed to investigate the influence of the loads from the backfilling materials and waste package stacks on the mechanical stress of the disposed of wastes and containers. It was identified that the current design of the waste package and the compressive strength criterion for the solidified waste would not be enough to maintain structural stability. Therefore, an enhanced criterion for the compressive strength of the solidified waste and several reinforced structural designs for the disposal concrete container were proposed to prevent failure of the waste package based on the results of parametric studies
Reproductive ecology of interior least tern and piping plover in relation to Platte River hydrology and sandbar dynamics
Historical and contemporary use of large, economically important rivers by threatened and/or endangered species in the United States is a subject of great interest to a wide range of stakeholders. In a recent study of the Platte River in Nebraska, Farnsworth et al. (2017) (hereinafter referred to as “the authors” or “Farnsworth et al.”) used distributions of nest initiation dates taken mostly from human-created, off-channel habitats and a model of emergent sandbar habitat to evaluate the hypothesis that least terns (Sternula antillarum) and piping plovers (Charadrius melodus) are physiologically adapted to initiate nests concurrent with the cessation of spring river flow rises. The authors conclude that (1) these species are not now, nor were they in the past, physiologically adapted to the hydrology of the Platte River, (2) habitats in the Platte River did not, and cannot support reproductive levels sufficient to maintain species subpopulations, (3) the gap in local elevation between peak river stage and typical sandbar height, in combination with the timing of the average spring flood, creates a physical environment which limits opportunities for successful nesting and precludes persistence by either species, and (4) the presence of off-channel habitats, including human-created sand and gravel mines, natural lakes, and a playa wetland, allowed the species to expand into the Platte River basin
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