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Norcross, Brenda L. - One of the best experts on this subject based on the ideXlab platform.

  • Some Thoughts on Estimating Change to Arctic Cod Populations from Hypothetical Oil Spills in the Eastern Alaska Beaufort Sea
    NRC Research Press (a division of Canadian Science Publishing), 2017
    Co-Authors: Gallaway, Benny J, Konkel, Wolfgang J, Norcross, Brenda L.
    Abstract:

    We describe a fecundity-hindcast model that incorporates Arctic cod Boreogadus saida acute toxicity data, field studies of Arctic cod larval distribution and abundance, natural mortality estimates for Arctic cod eggs and larvae, and an oil spill fate model in Alaska Beaufort Sea. Three orders of magnitude of spill events (1,000 tons, 10,000 tons, 100,000 tons) were evaluated for both physically and chemically dispersed oil. Using worst-case assumptions in our model, a 100,000-ton spill of crude oil treated with dispersants resulted in 266 million m3 of water that exceeded our acute toxicity threshold, compared to a volume of 71 million m3 for a 100,000-ton spill not treated with dispersants, and resulted in exposure of about 2 million Arctic cod larvae remaining from an initial 87 million eggs. This represents the reproductive output of about 7,300 adult females. Adult Arctic cod populations in the Alaska Beaufort Number in the 10s to 100s of millions. The results show that even with an order of magnitude variation in exposure, the effect of dispersing a large oil spill on the regional cod population is expected to be insignificant (~0.7%). The recent hiatus in Arctic oil and gas development affords an opportunity to acquire additional data to further strengthen this conclusion.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Brenda L. Norcross - One of the best experts on this subject based on the ideXlab platform.

  • Some thoughts on estimating change to Arctic cod populations from hypothetical oil spills in the eastern Alaska Beaufort Sea
    Arctic Science, 2017
    Co-Authors: Benny J. Gallaway, Wolfgang J. Konkel, Brenda L. Norcross
    Abstract:

    We describe a fecundity-hindcast model that incorporates Arctic cod (Boreogadus saida) acute toxicity data, field studies of Arctic cod larval distribution and abundance, natural mortality estimates for Arctic cod eggs and larvae, and an oil spill fate model in Alaska Beaufort Sea. Three orders of magnitude of spill events (1000, 10 000, and 100 000 tons) were evaluated for both physically and chemically dispersed oil. Using worst-case assumptions in our model, a 100 000 ton spill of crude oil treated with dispersants resulted in 266 million m3 of water that exceeded our acute toxicity threshold, compared to a volume of 71 million m3 for a 100 000 ton spill not treated with dispersants, and resulted in exposure of about 2 million Arctic cod larvae remaining from an initial 87 million eggs. This represents the reproductive output of about 7300 adult females. Adult Arctic cod populations in the Alaska Beaufort Number in the tens to hundreds of millions. The results show that even with an order of magnitude ...

Gallaway, Benny J - One of the best experts on this subject based on the ideXlab platform.

  • Some Thoughts on Estimating Change to Arctic Cod Populations from Hypothetical Oil Spills in the Eastern Alaska Beaufort Sea
    NRC Research Press (a division of Canadian Science Publishing), 2017
    Co-Authors: Gallaway, Benny J, Konkel, Wolfgang J, Norcross, Brenda L.
    Abstract:

    We describe a fecundity-hindcast model that incorporates Arctic cod Boreogadus saida acute toxicity data, field studies of Arctic cod larval distribution and abundance, natural mortality estimates for Arctic cod eggs and larvae, and an oil spill fate model in Alaska Beaufort Sea. Three orders of magnitude of spill events (1,000 tons, 10,000 tons, 100,000 tons) were evaluated for both physically and chemically dispersed oil. Using worst-case assumptions in our model, a 100,000-ton spill of crude oil treated with dispersants resulted in 266 million m3 of water that exceeded our acute toxicity threshold, compared to a volume of 71 million m3 for a 100,000-ton spill not treated with dispersants, and resulted in exposure of about 2 million Arctic cod larvae remaining from an initial 87 million eggs. This represents the reproductive output of about 7,300 adult females. Adult Arctic cod populations in the Alaska Beaufort Number in the 10s to 100s of millions. The results show that even with an order of magnitude variation in exposure, the effect of dispersing a large oil spill on the regional cod population is expected to be insignificant (~0.7%). The recent hiatus in Arctic oil and gas development affords an opportunity to acquire additional data to further strengthen this conclusion.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Benny J. Gallaway - One of the best experts on this subject based on the ideXlab platform.

  • Some thoughts on estimating change to Arctic cod populations from hypothetical oil spills in the eastern Alaska Beaufort Sea
    Arctic Science, 2017
    Co-Authors: Benny J. Gallaway, Wolfgang J. Konkel, Brenda L. Norcross
    Abstract:

    We describe a fecundity-hindcast model that incorporates Arctic cod (Boreogadus saida) acute toxicity data, field studies of Arctic cod larval distribution and abundance, natural mortality estimates for Arctic cod eggs and larvae, and an oil spill fate model in Alaska Beaufort Sea. Three orders of magnitude of spill events (1000, 10 000, and 100 000 tons) were evaluated for both physically and chemically dispersed oil. Using worst-case assumptions in our model, a 100 000 ton spill of crude oil treated with dispersants resulted in 266 million m3 of water that exceeded our acute toxicity threshold, compared to a volume of 71 million m3 for a 100 000 ton spill not treated with dispersants, and resulted in exposure of about 2 million Arctic cod larvae remaining from an initial 87 million eggs. This represents the reproductive output of about 7300 adult females. Adult Arctic cod populations in the Alaska Beaufort Number in the tens to hundreds of millions. The results show that even with an order of magnitude ...

Christoph Reichel - One of the best experts on this subject based on the ideXlab platform.

  • Computational fluid dynamics study to reduce heat losses at the receiver of a solar tower plant
    Solar Energy, 2019
    Co-Authors: Alexander Schmitt, Frank Dinter, Christoph Reichel
    Abstract:

    Abstract Today, renewable energy systems are developing rapidly and are reaching economic competitiveness with conventional power plants. Due to their ability to efficiently integrate energy storage systems, concentrated solar power plants are ascribed a high potential for energy generation. Typically, the usage of molten salt as heat transfer fluid in the receiver reaches thermal efficiencies of 80–88% (de Meyer et al., 2016. Thermal Resistance Model for CSP Central Receivers). Placing the dome on top of the tower may be a measure in order to reduce the heat losses at the receiver. In the presented work, a computational fluid dynamics 1 (CFD) study with the commercial simulation package STAR-CCM+ 2 (Simulation of Turbulent flow in Arbitrary Regions - Computational Continuum Mechanics, C++ based) was executed to investigate the impact of placing the dome geometry on top of the solar tower. Mainly the potential to reduce convective and radiative heat losses at the molten salt receiver at various wind loads was analyzed. The respective Crescent Dunes plant in Las Vegas (Nevada) with an electrical net power of 110 MW was chosen as reference for generating the required input data for the simulations. Overall six simulation models were set up: two geometries, one with and one without a dome, and each of the geometries with three variable wind loads (Beaufort Number (BN 3 ) 2, 4 and 6). In the main part, the radiative and convective heat losses at the receiver were analyzed for the BN 4 and afterwards compared to the results with the models BN 2 and BN 6. The construction of the dome reduced the heat losses at the receiver by 1.92 MW (BN 4) with the radiation energy savings (1.32 MW) being higher than the reduction of convective losses (0.60 MW). Furthermore, the reduced heat losses are 1.79 MW for BN 2 and only 0.43 MW for BN 6. Besides in the last case, the convective losses actually rise and the function of the dome turns out as counterproductive. Nevertheless, the results can be fundamental for further research projects as the dependence of the heat losses on variations of the dome form and the installation of components to disturb or eliminate a convective heat flow at the receiver can be essential to future studies. However, each concept must be seen in terms of economic and technical feasibility.