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1

Argonne's GREET Model - Driving Transportation Solutions  

NLE Websites -- All DOE Office Websites (Extended Search)

Driving Driving Transportation Solutions Model Argonne's GREET D r i v i n g Tr a n s p o r t a t i o n S o l u t i o n s ARGONNE'S GREET Argonne's GREET model is widely recognized as the "gold standard" for evaluating and comparing the energy and environmental impacts of transportation fuels and advanced vehicles. The Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) model is a one-of-a-kind analytical tool that simulates the energy use and emissions output of various vehicle and fuel combinations. Sponsored by the U.S. Department of Energy's (DOE) Office of Energy Efficiency and Renewable Energy, the free software program gives researchers the unique ability to analyze technologies over an entire life cycle - from well to wheels and from raw material mining to vehicle disposal.

2

Argonne GREET Model  

NLE Websites -- All DOE Office Websites (Extended Search)

Laboratory Transportation Technology R&D Center DOE Logo Laboratory Transportation Technology R&D Center DOE Logo About TTRDC Mission Experts Facilities Tools Publications Awards Media Center Site Index Search TTRDC ... Search Argonne Home > Transportation Technology R & D Center > Modeling_simulation > Alternative Fuels Autonomie Batteries Engines Green Racing ... ... GREET * Fuel-Cycle Model * Power Water Model * Copyright Statement * Mini-tool and Results * Vehicle-Cycle Model * Publications * AFLEET Tool * Fleet Footprint Calculator * Travel Carbon Calculator * Workshops * Contact ... ... Hybrid Electric Vehicles Hydrogen & Fuel Cells Materials Modeling, Simulation & Software Plug-In Hybrid Electric Vehicles PSAT Smart Grid Student Competitions Transportation Research and Analysis Computing Center

3

Development and applications of GREET 2.7 -- The Transportation Vehicle-CycleModel.  

DOE Green Energy (OSTI)

Argonne National Laboratory has developed a vehicle-cycle module for the Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) model. The fuel-cycle GREET model has been cited extensively and contains data on fuel cycles and vehicle operations. The vehicle-cycle model evaluates the energy and emission effects associated with vehicle material recovery and production, vehicle component fabrication, vehicle assembly, and vehicle disposal/recycling. With the addition of the vehicle-cycle module, the GREET model now provides a comprehensive, lifecycle-based approach to compare the energy use and emissions of conventional and advanced vehicle technologies (e.g., hybrid electric vehicles and fuel cell vehicles). This report details the development and application of the GREET 2.7 model. The current model includes six vehicles--a conventional material and a lightweight material version of a mid-size passenger car with the following powertrain systems: internal combustion engine, internal combustion engine with hybrid configuration, and fuel cell with hybrid configuration. The model calculates the energy use and emissions that are required for vehicle component production; battery production; fluid production and use; and vehicle assembly, disposal, and recycling. This report also presents vehicle-cycle modeling results. In order to put these results in a broad perspective, the fuel-cycle model (GREET 1.7) was used in conjunction with the vehicle-cycle model (GREET 2.7) to estimate total energy-cycle results.

Burnham, A.; Wang, M. Q.; Wu, Y.

2006-12-20T23:59:59.000Z

4

DOE Hydrogen Analysis Repository: GREET Model  

NLE Websites -- All DOE Office Websites (Extended Search)

GREET Model GREET Model Project Summary Full Title: Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) Model Project ID: 84 Principal Investigator: Michael Wang Keywords: Well-to-wheels (WTW); emissions; greenhouse gases (GHG); fuel cell vehicles (FCV) Purpose GREET supports Milestone 24 of the Systems Analysis activity of the DOE Hydrogen Program: Complete baseline economic, energy efficiency, and environmental targets for fossil, nuclear and renewable hydrogen production and delivery technologies. GREET also supports the 3rd objective listed in the DOE Hydrogen Program's Systems Analysis Plan: Well-to-Wheels Analysis: Conduct on-going, integrated well-to-wheels analysis of hydrogen pathways for introducing hydrogen as a transportation fuel. The analysis

5

GREET 1.5 - transportation fuel-cycle model - Vol. 1 : methodology, development, use, and results.  

DOE Green Energy (OSTI)

This report documents the development and use of the most recent version (Version 1.5) of the Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model. The model, developed in a spreadsheet format, estimates the full fuel-cycle emissions and energy associated with various transportation fuels and advanced vehicle technologies for light-duty vehicles. The model calculates fuel-cycle emissions of five criteria pollutants (volatile organic compounds, carbon monoxide, nitrogen oxides, particulate matter with diameters of 10 micrometers or less, and sulfur oxides) and three greenhouse gases (carbon dioxide, methane, and nitrous oxide). The model also calculates total energy consumption, fossil fuel consumption, and petroleum consumption when various transportation fuels are used. The GREET model includes the following cycles: petroleum to conventional gasoline, reformulated gasoline, conventional diesel, reformulated diesel, liquefied petroleum gas, and electricity via residual oil; natural gas to compressed natural gas, liquefied natural gas, liquefied petroleum gas, methanol, Fischer-Tropsch diesel, dimethyl ether, hydrogen, and electricity; coal to electricity; uranium to electricity; renewable energy (hydropower, solar energy, and wind) to electricity; corn, woody biomass, and herbaceous biomass to ethanol; soybeans to biodiesel; flared gas to methanol, dimethyl ether, and Fischer-Tropsch diesel; and landfill gases to methanol. This report also presents the results of the analysis of fuel-cycle energy use and emissions associated with alternative transportation fuels and advanced vehicle technologies to be applied to passenger cars and light-duty trucks.

Wang, M. Q.

1999-10-06T23:59:59.000Z

6

GREET 1.0 -- Transportation fuel cycles model: Methodology and use  

DOE Green Energy (OSTI)

This report documents the development and use of the Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model. The model, developed in a spreadsheet format, estimates the full fuel-cycle emissions and energy use associated with various transportation fuels for light-duty vehicles. The model calculates fuel-cycle emissions of five criteria pollutants (volatile organic compounds, Co, NOx, SOx, and particulate matter measuring 10 microns or less) and three greenhouse gases (carbon dioxide, methane, and nitrous oxide). The model also calculates the total fuel-cycle energy consumption, fossil fuel consumption, and petroleum consumption using various transportation fuels. The GREET model includes 17 fuel cycles: petroleum to conventional gasoline, reformulated gasoline, clean diesel, liquefied petroleum gas, and electricity via residual oil; natural gas to compressed natural gas, liquefied petroleum gas, methanol, hydrogen, and electricity; coal to electricity; uranium to electricity; renewable energy (hydropower, solar energy, and wind) to electricity; corn, woody biomass, and herbaceous biomass to ethanol; and landfill gases to methanol. This report presents fuel-cycle energy use and emissions for a 2000 model-year car powered by each of the fuels that are produced from the primary energy sources considered in the study.

Wang, M.Q.

1996-06-01T23:59:59.000Z

7

The Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) Model  

E-Print Network (OSTI)

Flared Gas Landfill Gas Figure 1. Fuel-Cycle Pathways Included in GREET 1.5 3. Computer System in either gaseous or liquid form; either form may be selected for simulation. Pathways from flared gas CIDI vehicles: diesel Compressed natural gas vehicles: Bi-fuel Dedicated fuel Dedicated liquefied

Argonne National Laboratory

8

Development and use of the GREET model to estimate fuel-cycle energy use and emissions of various transportation technologies and fuels  

SciTech Connect

This report documents the development and use of the Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model. The model, developed in a spreadsheet format, estimates the full fuel- cycle emissions and energy use associated with various transportation fuels for light-duty vehicles. The model calculates fuel-cycle emissions of five criteria pollutants (volatile organic compounds, carbon monoxide, nitrogen oxides, sulfur oxides, and particulate matter measuring 10 microns or less) and three greenhouse gases (carbon dioxide, methane, and nitrous oxide). The model also calculates the total fuel-cycle energy consumption, fossil fuel consumption, and petroleum consumption using various transportation fuels. The GREET model includes 17 fuel cycles: petroleum to conventional gasoline, reformulated gasoline, clean diesel, liquefied petroleum gas, and electricity via residual oil; natural gas to compressed natural gas, liquefied petroleum gas, methanol, hydrogen, and electricity; coal to electricity; uranium to electricity; renewable energy (hydrogen, solar energy, and wind) to electricity; corn, woody biomass, and herbaceous biomass to ethanol; and landfill gases to methanol. This report presents fuel-cycle energy use and emissions for a 2000 model-year car powered by each of the fuels that are produced from the primary energy sources considered in the study.

Wang, M.Q.

1996-03-01T23:59:59.000Z

9

GREET Fleet | Open Energy Information  

Open Energy Info (EERE)

GREET Fleet GREET Fleet Jump to: navigation, search Tool Summary Name: The Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation Model (GREET) Agency/Company /Organization: Argonne National Laboratory Sector: Energy Focus Area: Transportation Phase: Determine Baseline, Evaluate Options Topics: Baseline projection, GHG inventory Resource Type: Online calculator, Software/modeling tools User Interface: Spreadsheet Website: greet.es.anl.gov/carbon_footprint_calculator OpenEI Keyword(s): EERE tool References: http://greet.es.anl.gov/carbon_footprint_calculator Logo: The Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation Model (GREET) The Department of Energy's Clean Cities Program has enlisted the expertise of Argonne to assist in measuring the petroleum displacement and greenhouse

10

Life-Cycle Energy Use and Greenhouse Gas Emission Implicaitons of Brazilian Sugarcane Ethanol Simulated with the GREET Model  

Alternative Fuels and Advanced Vehicles Data Center (EERE)

Life-Cycle Energy Use and Greenhouse Gas Emission Implications of Life-Cycle Energy Use and Greenhouse Gas Emission Implications of Brazilian Sugarcane Ethanol Simulated with the GREET Model Michael Wang*, May Wu, Hong Huo and Jiahong Liu Center for Transportation Research, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439, USA. *Contact author: Tel: +1 (630) 252 2819 Fax: +1 (630) 252 3443 Email: mqwang@anl.gov In International Sugar Journal 2008, Vol. 110, No. 1317 ABSTRACT By using data available in the open literature, we expanded the Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model developed by Argonne National Laboratory to include Brazilian-grown sugarcane ethanol. With the expanded GREET model, we examined the well-to-wheels (WTW) energy use and

11

Overview of GREET Model Development at  

E-Print Network (OSTI)

Production and Vehicle Use Vehicle Cycle Fuel Cycle Well to Pump PumptoWheels #12;4 WTW AnalysisVehicle (NG ) H 2 FCV (Electrolysis) GHGEmissions(g/mi.) Pump to Wheels Well to Pump #12;5 LCA Models have Motors Corporation (2000-05): produced two reports that are standard citation by auto and oil industry

Argonne National Laboratory

12

Introduction of GREET1.7 Excel Model  

E-Print Network (OSTI)

and emissions for NG-based fuels (plus flared gas to liquid fuels; landfill gas to methanol; and biomass;16 GREET Includes a Varity of Hydrogen Production Pathways NNA Flared Gas NA NG NNA NG Central Plant Flared Gas NA NG NNA NG Central Plant Production: No C Sequestration C Sequestration Central Plant

Argonne National Laboratory

13

Overview of GREET M d l D l t tModel Development at  

E-Print Network (OSTI)

(petroleum, natural gas, and coal combined) Petroleum CoalCoal Natural gas The GREET model and its documents residues FT Diesel Residual Oil Coal Nuclear Energy Hydrogen Hydrogen FT Di l Coal Natural Gas Nuclear fertilizer plants E­ Energy use ­ Natural gas vs. coal as feedstock Farmingg ­ Crop and biomass yields

Argonne National Laboratory

14

Fuel-Cycle Analysis of Hydrogen-Powered Fuel-Cell Systems with the GREET Model  

NLE Websites -- All DOE Office Websites (Extended Search)

Cycle Analysis of Hydrogen-Powered Cycle Analysis of Hydrogen-Powered Fuel-Cell Systems with the GREET Model Michael Wang Argonne National Laboratory June 10, 2008 Project ID # AN2 This presentation does not contain any proprietary, confidential, or otherwise restricted information 2 Overview * Project start date: Oct. 2002 * Project end date: Continuous * Percent complete: N/A * Inconsistent data, assumptions, and guidelines * Suite of models and tools * Unplanned studies and analyses * Total project funding from DOE: $2.04 million through FY08 * Funding received in FY07: $450k * Funding for FY08: $840k Budget * H2A team * PSAT team * NREL * Industry stakeholders Partners Timeline Barriers to Address 3 Objectives * Expand and update the GREET model for hydrogen production pathways and for applications of FCVs and other FC systems

15

Well-to-wheels analysis of fast pyrolysis pathways with the GREET model.  

Science Conference Proceedings (OSTI)

The pyrolysis of biomass can help produce liquid transportation fuels with properties similar to those of petroleum gasoline and diesel fuel. Argonne National Laboratory conducted a life-cycle (i.e., well-to-wheels [WTW]) analysis of various pyrolysis pathways by expanding and employing the Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model. The WTW energy use and greenhouse gas (GHG) emissions from the pyrolysis pathways were compared with those from the baseline petroleum gasoline and diesel pathways. Various pyrolysis pathway scenarios with a wide variety of possible hydrogen sources, liquid fuel yields, and co-product application and treatment methods were considered. At one extreme, when hydrogen is produced from natural gas and when bio-char is used for process energy needs, the pyrolysis-based liquid fuel yield is high (32% of the dry mass of biomass input). The reductions in WTW fossil energy use and GHG emissions relative to those that occur when baseline petroleum fuels are used, however, is modest, at 50% and 51%, respectively, on a per unit of fuel energy basis. At the other extreme, when hydrogen is produced internally via reforming of pyrolysis oil and when bio-char is sequestered in soil applications, the pyrolysis-based liquid fuel yield is low (15% of the dry mass of biomass input), but the reductions in WTW fossil energy use and GHG emissions are large, at 79% and 96%, respectively, relative to those that occur when baseline petroleum fuels are used. The petroleum energy use in all scenarios was restricted to biomass collection and transportation activities, which resulted in a reduction in WTW petroleum energy use of 92-95% relative to that found when baseline petroleum fuels are used. Internal hydrogen production (i.e., via reforming of pyrolysis oil) significantly reduces fossil fuel use and GHG emissions because the hydrogen from fuel gas or pyrolysis oil (renewable sources) displaces that from fossil fuel natural gas and the amount of fossil natural gas used for hydrogen production is reduced; however, internal hydrogen production also reduces the potential petroleum energy savings (per unit of biomass input basis) because the fuel yield declines dramatically. Typically, a process that has a greater liquid fuel yield results in larger petroleum savings per unit of biomass input but a smaller reduction in life-cycle GHG emissions. Sequestration of the large amount of bio-char co-product (e.g., in soil applications) provides a significant carbon dioxide credit, while electricity generation from bio-char combustion provides a large energy credit. The WTW energy and GHG emissions benefits observed when a pyrolysis oil refinery was integrated with a pyrolysis reactor were small when compared with those that occur when pyrolysis oil is distributed to a distant refinery, since the activities associated with transporting the oil between the pyrolysis reactors and refineries have a smaller energy and emissions footprint than do other activities in the pyrolysis pathway.

Han, J.; Elgowainy, A.; Palou-Rivera, I.; Dunn, J.B.; Wang, M.Q. (Energy Systems)

2011-12-01T23:59:59.000Z

16

Life-Cycle Water Impacts of U.S. Transportation Fuels  

E-Print Network (OSTI)

Water Intensity of Transportation. Environmental Science &and Energy Use in Transportation (GREET) Model, Version 1.5.Water Intensity of Transportation. Environmental Science &

Scown, Corinne Donahue

2010-01-01T23:59:59.000Z

17

What is the GREET Fleet Footprint Calculator  

Alternative Fuels and Advanced Vehicles Data Center (EERE)

GREET Fleet Calculator can estimate petroleum and carbon GREET Fleet Calculator can estimate petroleum and carbon footprints of both on-road vehicles and off-road equipment. What is the GREET Fleet Footprint Calculator? As early adopters of new vehicle technologies, fleets are vital to the success of alternative fuels and advanced vehicles (AFVs). The Greenhouse gases, Regulated Emis- sions, and Energy use in Transportation (GREET) Fleet Foot- print Calculator can help fleets decide on the AFVs that will best help them meet a variety of organizational goals and legal requirements, including reducing their petroleum use and greenhouse gas (GHG) emissions. Currently, the United States imports nearly half of its oil. 1 Because the United States uses about 70% of its oil for transportation, decreasing petroleum consumption in vehicles can substantially

18

Well-to-Wheels analysis of landfill gas-based pathways and their addition to the GREET model.  

SciTech Connect

Today, approximately 300 million standard cubic ft/day (mmscfd) of natural gas and 1600 MW of electricity are produced from the decomposition of organic waste at 519 U.S. landfills (EPA 2010a). Since landfill gas (LFG) is a renewable resource, this energy is considered renewable. When used as a vehicle fuel, compressed natural gas (CNG) produced from LFG consumes up to 185,000 Btu of fossil fuel and generates from 1.5 to 18.4 kg of carbon dioxide-equivalent (CO{sub 2}e) emissions per million Btu of fuel on a 'well-to-wheel' (WTW) basis. This compares with approximately 1.1 million Btu and 78.2 kg of CO{sub 2}e per million Btu for CNG from fossil natural gas and 1.2 million Btu and 97.5 kg of CO{sub 2}e per million Btu for petroleum gasoline. Because of the additional energy required for liquefaction, LFG-based liquefied natural gas (LNG) requires more fossil fuel (222,000-227,000 Btu/million Btu WTW) and generates more GHG emissions (approximately 22 kg CO{sub 2}e /MM Btu WTW) if grid electricity is used for the liquefaction process. However, if some of the LFG is used to generate electricity for gas cleanup and liquefaction (or compression, in the case of CNG), vehicle fuel produced from LFG can have no fossil fuel input and only minimal GHG emissions (1.5-7.7 kg CO{sub 2}e /MM Btu) on a WTW basis. Thus, LFG-based natural gas can be one of the lowest GHG-emitting fuels for light- or heavy-duty vehicles. This report discusses the size and scope of biomethane resources from landfills and the pathways by which those resources can be turned into and utilized as vehicle fuel. It includes characterizations of the LFG stream and the processes used to convert low-Btu LFG into high-Btu renewable natural gas (RNG); documents the conversion efficiencies and losses of those processes, the choice of processes modeled in GREET, and other assumptions used to construct GREET pathways; and presents GREET results by pathway stage. GREET estimates of well-to-pump (WTP), pump-to-wheel (PTW), and WTW energy, fossil fuel, and GHG emissions for each LFG-based pathway are then summarized and compared with similar estimates for fossil natural gas and petroleum pathways.

Mintz, M.; Han, J.; Wang, M.; Saricks, C.; Energy Systems

2010-06-30T23:59:59.000Z

19

Well-to-Wheels analysis of landfill gas-based pathways and their addition to the GREET model.  

SciTech Connect

Today, approximately 300 million standard cubic ft/day (mmscfd) of natural gas and 1600 MW of electricity are produced from the decomposition of organic waste at 519 U.S. landfills (EPA 2010a). Since landfill gas (LFG) is a renewable resource, this energy is considered renewable. When used as a vehicle fuel, compressed natural gas (CNG) produced from LFG consumes up to 185,000 Btu of fossil fuel and generates from 1.5 to 18.4 kg of carbon dioxide-equivalent (CO{sub 2}e) emissions per million Btu of fuel on a 'well-to-wheel' (WTW) basis. This compares with approximately 1.1 million Btu and 78.2 kg of CO{sub 2}e per million Btu for CNG from fossil natural gas and 1.2 million Btu and 97.5 kg of CO{sub 2}e per million Btu for petroleum gasoline. Because of the additional energy required for liquefaction, LFG-based liquefied natural gas (LNG) requires more fossil fuel (222,000-227,000 Btu/million Btu WTW) and generates more GHG emissions (approximately 22 kg CO{sub 2}e /MM Btu WTW) if grid electricity is used for the liquefaction process. However, if some of the LFG is used to generate electricity for gas cleanup and liquefaction (or compression, in the case of CNG), vehicle fuel produced from LFG can have no fossil fuel input and only minimal GHG emissions (1.5-7.7 kg CO{sub 2}e /MM Btu) on a WTW basis. Thus, LFG-based natural gas can be one of the lowest GHG-emitting fuels for light- or heavy-duty vehicles. This report discusses the size and scope of biomethane resources from landfills and the pathways by which those resources can be turned into and utilized as vehicle fuel. It includes characterizations of the LFG stream and the processes used to convert low-Btu LFG into high-Btu renewable natural gas (RNG); documents the conversion efficiencies and losses of those processes, the choice of processes modeled in GREET, and other assumptions used to construct GREET pathways; and presents GREET results by pathway stage. GREET estimates of well-to-pump (WTP), pump-to-wheel (PTW), and WTW energy, fossil fuel, and GHG emissions for each LFG-based pathway are then summarized and compared with similar estimates for fossil natural gas and petroleum pathways.

Mintz, M.; Han, J.; Wang, M.; Saricks, C.; Energy Systems

2010-06-30T23:59:59.000Z

20

The Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation  

Open Energy Info (EERE)

Gases, Regulated Emissions, and Energy Use in Transportation Gases, Regulated Emissions, and Energy Use in Transportation Model (GREET) Jump to: navigation, search Tool Summary Name: The Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation Model (GREET Fleet) Agency/Company /Organization: Argonne National Laboratory Sector: Energy Focus Area: Greenhouse Gas, Transportation Phase: Determine Baseline, Evaluate Options Topics: Baseline projection, GHG inventory Resource Type: Software/modeling tools User Interface: Spreadsheet Website: greet.es.anl.gov/main Cost: Free OpenEI Keyword(s): EERE tool, The Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation Model, GREET References: GREET Fleet Main Page[1] Logo: The Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation Model (GREET Fleet)

Note: This page contains sample records for the topic "transportation greet model" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Waste-to-wheel analysis of anaerobic-digestion-based renewable natural gas pathways with the GREET model.  

SciTech Connect

In 2009, manure management accounted for 2,356 Gg or 107 billion standard cubic ft of methane (CH{sub 4}) emissions in the United States, equivalent to 0.5% of U.S. natural gas (NG) consumption. Owing to the high global warming potential of methane, capturing and utilizing this methane source could reduce greenhouse gas (GHG) emissions. The extent of that reduction depends on several factors - most notably, how much of this manure-based methane can be captured, how much GHG is produced in the course of converting it to vehicular fuel, and how much GHG was produced by the fossil fuel it might displace. A life-cycle analysis was conducted to quantify these factors and, in so doing, assess the impact of converting methane from animal manure into renewable NG (RNG) and utilizing the gas in vehicles. Several manure-based RNG pathways were characterized in the GREET (Greenhouse gases, Regulated Emissions, and Energy use in Transportation) model, and their fuel-cycle energy use and GHG emissions were compared to petroleum-based pathways as well as to conventional fossil NG pathways. Results show that despite increased total energy use, both fossil fuel use and GHG emissions decline for most RNG pathways as compared with fossil NG and petroleum. However, GHG emissions for RNG pathways are highly dependent on the specifics of the reference case, as well as on the process energy emissions and methane conversion factors assumed for the RNG pathways. The most critical factors are the share of flared controllable CH{sub 4} and the quantity of CH{sub 4} lost during NG extraction in the reference case, the magnitude of N{sub 2}O lost in the anaerobic digestion (AD) process and in AD residue, and the amount of carbon sequestered in AD residue. In many cases, data for these parameters are limited and uncertain. Therefore, more research is needed to gain a better understanding of the range and magnitude of environmental benefits from converting animal manure to RNG via AD.

Han, J.; Mintz, M.; Wang, M. (Energy Systems)

2011-12-14T23:59:59.000Z

22

Life-Cycle Water Impacts of U.S. Transportation Fuels  

E-Print Network (OSTI)

Transportation (GREET) Model, Version 1.5. Argonne NationalLaboratory: Argonne, IL, 1999; http://and Petroleum Gasoline. Argonne National Laboratory:

Scown, Corinne Donahue

2010-01-01T23:59:59.000Z

23

Life-cycle analysis of alternative aviation fuels in GREET  

SciTech Connect

The Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) model, developed at Argonne National Laboratory, has been expanded to include well-to-wake (WTWa) analysis of aviation fuels and aircraft. This report documents the key WTWa stages and assumptions for fuels that represent alternatives to petroleum jet fuel. The aviation module in GREET consists of three spreadsheets that present detailed characterizations of well-to-pump and pump-to-wake parameters and WTWa results. By using the expanded GREET version (GREET1{_}2011), we estimate WTWa results for energy use (total, fossil, and petroleum energy) and greenhouse gas (GHG) emissions (carbon dioxide, methane, and nitrous oxide) for (1) each unit of energy (lower heating value) consumed by the aircraft or (2) each unit of distance traveled/ payload carried by the aircraft. The fuel pathways considered in this analysis include petroleum-based jet fuel from conventional and unconventional sources (i.e., oil sands); Fisher-Tropsch (FT) jet fuel from natural gas, coal, and biomass; bio-jet fuel from fast pyrolysis of cellulosic biomass; and bio-jet fuel from vegetable and algal oils, which falls under the American Society for Testing and Materials category of hydroprocessed esters and fatty acids. For aircraft operation, we considered six passenger aircraft classes and four freight aircraft classes in this analysis. Our analysis revealed that, depending on the feedstock source, the fuel conversion technology, and the allocation or displacement credit methodology applied to co-products, alternative bio-jet fuel pathways have the potential to reduce life-cycle GHG emissions by 55-85 percent compared with conventional (petroleum-based) jet fuel. Although producing FT jet fuel from fossil feedstock sources - such as natural gas and coal - could greatly reduce dependence on crude oil, production from such sources (especially coal) produces greater WTWa GHG emissions compared with petroleum jet fuel production unless carbon management practices, such as carbon capture and storage, are used.

Elgowainy, A.; Han, J.; Wang, M.; Carter, N.; Stratton, R.; Hileman, J.; Malwitz, A.; Balasubramanian, S. (Energy Systems)

2012-07-23T23:59:59.000Z

24

Mobility chains analysis of technologies for passenger cars and light duty vehicles fueled with biofuels : application of the Greet model to project the role of biomass in America's energy future (RBAEF) project.  

DOE Green Energy (OSTI)

The Role of Biomass in America's Energy Future (RBAEF) is a multi-institution, multiple-sponsor research project. The primary focus of the project is to analyze and assess the potential of transportation fuels derived from cellulosic biomass in the years 2015 to 2030. For this project, researchers at Dartmouth College and Princeton University designed and simulated an advanced fermentation process to produce fuel ethanol/protein, a thermochemical process to produce Fischer-Tropsch diesel (FTD) and dimethyl ether (DME), and a combined heat and power plant to co-produce steam and electricity using the ASPEN Plus{trademark} model. With support from the U.S. Department of Energy (DOE), Argonne National Laboratory (ANL) conducted, for the RBAEF project, a mobility chains or well-to-wheels (WTW) analysis using the Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) model developed at ANL. The mobility chains analysis was intended to estimate the energy consumption and emissions associated with the use of different production biofuels in light-duty vehicle technologies.

Wu, M.; Wu, Y.; Wang, M; Energy Systems

2008-01-31T23:59:59.000Z

25

Mobility chains analysis of technologies for passenger cars and light duty vehicles fueled with biofuels : application of the Greet model to project the role of biomass in America's energy future (RBAEF) project.  

SciTech Connect

The Role of Biomass in America's Energy Future (RBAEF) is a multi-institution, multiple-sponsor research project. The primary focus of the project is to analyze and assess the potential of transportation fuels derived from cellulosic biomass in the years 2015 to 2030. For this project, researchers at Dartmouth College and Princeton University designed and simulated an advanced fermentation process to produce fuel ethanol/protein, a thermochemical process to produce Fischer-Tropsch diesel (FTD) and dimethyl ether (DME), and a combined heat and power plant to co-produce steam and electricity using the ASPEN Plus{trademark} model. With support from the U.S. Department of Energy (DOE), Argonne National Laboratory (ANL) conducted, for the RBAEF project, a mobility chains or well-to-wheels (WTW) analysis using the Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) model developed at ANL. The mobility chains analysis was intended to estimate the energy consumption and emissions associated with the use of different production biofuels in light-duty vehicle technologies.

Wu, M.; Wu, Y.; Wang, M; Energy Systems

2008-01-31T23:59:59.000Z

26

Life Cycle Regulation of Transportation Fuels: Uncertainty and its Policy Implications  

E-Print Network (OSTI)

62 Default ethanol biorefineries modeled in GREET. Energyethanol facility. Corn biorefineries are generally built5.1: Default ethanol biorefineries modeled in GREET. Energy

Plevin, Richard Jay

2010-01-01T23:59:59.000Z

27

DOE Hydrogen and Fuel Cells Program: Macro System Model  

NLE Websites -- All DOE Office Websites (Extended Search)

and Energy Use in Transportation (GREET; versions 1 and 2) H2A Production H2A Delivery Scenario Analysis Model (HDSAM) Hydrogen Demand and Resource Analysis (HyDRA) HyPro...

28

Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation  

Open Energy Info (EERE)

Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) Model Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) Model Agency/Company /Organization: Argonne National Laboratory Focus Area: GHG Inventory Development Topics: Analysis Tools Website: greet.es.anl.gov/ This full life-cycle model evaluates the energy and emission impacts of advanced vehicle technologies and new transportation fuels. The model allows users to evaluate various vehicle and fuel combinations. How to Use This Tool This tool is most helpful when using these strategies: Shift - Change to low-carbon modes Improve - Enhance infrastructure & policies Learn more about the avoid, shift, improve framework for limiting air

29

Transportation Network Modeling in Passenger Transportation  

E-Print Network (OSTI)

. Summary & Future work 2 #12;NETPLAN Energy and Transportation Integration model A modeling frameworkTransportation Network Modeling in NETPLAN Passenger Transportation Venkat Krishnan Eirini;Outline 1. Introduction to NETPLAN 2. Transportation modeling- A review Freight Passenger 3. Developed

Daniels, Thomas E.

30

Rail-transportation modeling  

Science Conference Proceedings (OSTI)

Many different types of transportation models are used to model coal transportation by rail. To obtain realistic results, it is usually necessary to consider other modes in addition to rail and other commodities in addition to coal. For example, to know the potential bottlenecks on the rail system it is necessary to predict the total level of freight movement on the rail system. This requires modeling the movements of other commodities in addition to coal. To predict the levels of flows of both coal and non-coal commodities on the rail system, it is necessary to predict the share of total flows carried by rail. This requires accurate modeling of competing modes. To develop accurate rate models it is also necessary to have information on competing modes. This paper presents a collection of transportation models used to model the various aspects of coal transportation by rail and shows how they interact.

Tobin, R.L.

1982-01-01T23:59:59.000Z

31

Transport Model with Quasipions  

E-Print Network (OSTI)

We extend the normal transport model to include the medium effect on pions by treating them as quasiparticles. The property of the quasipion is determined using the delta-hole model. Modelling heavy-ion collisions at intermediate energies with the new transport equations, we find that it leads to an enhanced production of pions with low kinetic energies. This gives a plausible explanation for the observed enhancement of soft pions in the Bevalac experiments.

Xiong, L.; Ko, Che Ming; Koch, V.

1993-01-01T23:59:59.000Z

32

Transport Properties for Combustion Modeling  

NLE Websites -- All DOE Office Websites (Extended Search)

Transport Properties for Combustion Modeling Title Transport Properties for Combustion Modeling Publication Type Journal Article Year of Publication 2011 Authors Brown, Nancy J.,...

33

Transport Properties for Combustion Modeling  

E-Print Network (OSTI)

a critical role in combustion processes just as chemicalparameters are essential for combustion modeling; molecularwith Application to Combustion. Transport Theor Stat 2003;

Brown, N.J.

2010-01-01T23:59:59.000Z

34

Transportation Analysis, Modeling, and Simulation (TAMS) Application  

E-Print Network (OSTI)

Transportation Analysis, Modeling, and Simulation (TAMS) Application Center for Transportation Passenger Flows Supply Chain Efficiency Transportation: Energy Environment Safety Security Vehicle Technologies T he Center for Transportation Analysis (CTA) TAMS application is a web-based tool that supports

35

Transport Properties for Combustion Modeling  

E-Print Network (OSTI)

PRACTICE FOR CALCULATING TRANSPORT PROPERTIES V. 1. T HEcases; (4) performing more transport property measurementsFOR THE CALCULATION OF TRANSPORT PROPERTIES: III. EVALUATION

Brown, N.J.

2010-01-01T23:59:59.000Z

36

Model Recovery Procedure for Response to a Radiological Transportation...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

for Response to a Radiological Transportation Incident Model Recovery Procedure for Response to a Radiological Transportation Incident This Transportation Emergency...

37

Transportation Sector Module 2003, Model Documentation  

Reports and Publications (EIA)

Documents the objectives, analytical approach and development of the National Energy Modeling System (NEMS) Transportation Model (TRAN). The report catalogues and describes the model assumptions, computational methodology, parameter estimation techniques, model source code, and forecast results generated by the model.

John Maples

2003-02-01T23:59:59.000Z

38

Transportation Sector Module 2009, Model Documentation  

Reports and Publications (EIA)

Documents the objectives, analytical approach and development of the National Energy Modeling System (NEMS) Transportation Model (TRAN). The report catalogues and describes the model assumptions, computational methodology, parameter estimation techniques, model source code, and forecast results generated by the model.

John Maples

2009-06-02T23:59:59.000Z

39

Transportation Sector Module 2006, Model Documentation  

Reports and Publications (EIA)

Documents the objectives, analytical approach and development of the National Energy Modeling System (NEMS) Transportation Model (TRAN). The report catalogues and describes the model assumptions, computational methodology, parameter estimation techniques, model source code, and forecast results generated by the model.

John Maples

2006-09-01T23:59:59.000Z

40

Transportation Sector Module 2007, Model Documentation  

Reports and Publications (EIA)

Documents the objectives, analytical approach and development of the National Energy Modeling System (NEMS) Transportation Model (TRAN). The report catalogues and describes the model assumptions, computational methodology, parameter estimation techniques, model source code, and forecast results generated by the model.

John Maples

2007-05-09T23:59:59.000Z

Note: This page contains sample records for the topic "transportation greet model" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Transportation Sector Module 2002, Model Documentation  

Reports and Publications (EIA)

Documents the objectives, analytical approach and development of the National Energy Modeling System (NEMS) Transportation Model (TRAN). The report catalogues and describes the model assumptions, computational methodology, parameter estimation techniques, model source code, and forecast results generated by the model.

John Maples

2002-05-01T23:59:59.000Z

42

Transportation Sector Module 2001, Model Documentation  

Reports and Publications (EIA)

Documents the objectives, analytical approach and development of the National Energy Modeling System (NEMS) Transportation Model (TRAN). The report catalogues and describes the model assumptions, computational methodology, parameter estimation techniques, model source code, and forecast results generated by the model.

John Maples

2001-02-01T23:59:59.000Z

43

Transportation Sector Module 2004, Model Documentation  

Reports and Publications (EIA)

Documents the objectives, analytical approach and development of the National Energy Modeling System (NEMS) Transportation Model (TRAN). The report catalogues and describes the model assumptions, computational methodology, parameter estimation techniques, model source code, and forecast results generated by the model.

John Maples

2004-03-01T23:59:59.000Z

44

Transportation Sector Module 2005, Model Documentation  

Reports and Publications (EIA)

Documents the objectives, analytical approach and development of the National Energy Modeling System (NEMS) Transportation Model (TRAN). The report catalogues and describes the model assumptions, computational methodology, parameter estimation techniques, model source code, and forecast results generated by the model.

John Maples

2005-06-01T23:59:59.000Z

45

Transportation Sector Module 2008, Model Documentation  

Reports and Publications (EIA)

Documents the objectives, analytical approach and development of the National Energy Modeling System (NEMS) Transportation Model (TRAN). The report catalogues and describes the model assumptions, computational methodology, parameter estimation techniques, model source code, and forecast results generated by the model.

John Maples

2008-11-04T23:59:59.000Z

46

Scalability Modeling For Deterministic Particle Transport Solvers  

Science Conference Proceedings (OSTI)

In this paper, we propose a new parallel solver for the large-scale 3D neutron transport problems used in nuclear reactor simulations. Modern large-memory computers have made possible direct application of transport methods to large-scale computational ... Keywords: method of characteristics, performance model, scalability analysis, transport theory

Mohamed Dahmani; Robert Roy

2006-11-01T23:59:59.000Z

47

Argonne Transportation Current News  

NLE Websites -- All DOE Office Websites (Extended Search)

Current News November 21, 2013 -- Pixelligent Technologies Working with Argonne to Develop Nanoadditives under DOE SBIR Grant November 4, 2013 -- New GREET Model Released October 25, 2013 -- Argonne Creates IdleBox Toolkit for DOE's Clean Cities Initiative to Help Reduce Vehicle Idling September 23, 2013 -- New VISION Model Released for Estimating Potential Energy Use, Oil Use and Carbon Emission Impacts September 17, 2013 -- Water Assessment for Transportation Energy Resources (WATER) Tool Released September 9, 2013 -- Dileep Singh to Receive Prestigious Lee Hsun Award July 17, 2013 -- Summer 2013 TransForum now available July 10, 2013 -- Argonne Wins Four R&D 100 Awards March 23, 2013 -- White House Women's Leadership Summit on Climate and Energy recognizes Argonne scientists

48

Hydrogen Macro System Model User Guide, Version 1.2.1  

NLE Websites -- All DOE Office Websites (Extended Search)

Model (HDSAM), and GREET models, thus allowing analysis of the economics, primary energy-source requirements, and emissions of hydrogen production and delivery pathways....

49

Nutrient transport model in CHAHNIMEH manmade reservoirs  

Science Conference Proceedings (OSTI)

A Model for predicting nutrient transport to CHAHNIMEH reservoir is developed in this paper. Nitrogen and phosphorous have been simulated as the important parameters in evaluating water quality in the reservoir. Solar radiation and wind flow are considered ... Keywords: CHAHNIMEH, modeling, nutrient, reservoir, transport, water movement

Seyyed Ahmad Mirbagheri; Seyyed Arman Hashemi Monfared

2008-08-01T23:59:59.000Z

50

Transportation Sector Module 1999, Model Documentation  

Reports and Publications (EIA)

This report documents the objectives, analytical approach and development of the National Energy Modeling System (NEMS) Transportation Model (TRAN). The report catalogues and describes the model assumptions, computational methodology, parameter estimation techniques, model source code, and forecast results generated by the model.

John Maples

1999-01-01T23:59:59.000Z

51

Transportation Sector Module 1994, Model Documentation  

Reports and Publications (EIA)

This report documents the objectives, analytical approach and development of the National Energy Modeling System (NEMS) Transportation Model (TRAN). The report catalogues and describes the model assumptions, computational methodology, parameter estimation techniques, model source code, and forecast results generated by the model.

John Maples

1994-03-01T23:59:59.000Z

52

Highway and interline transportation routing models  

Science Conference Proceedings (OSTI)

The potential impacts associated with the transportation of hazardous materials are important issues to shippers, carriers, and the general public. Since transportation routes are a central characteristic in most of these issues, the prediction of likely routes is the first step toward the resolution of these issues. In addition, US Department of Transportation requirements (HM-164) mandate specific routes for shipments of highway controlled quantities of radioactive materials. In response to these needs, two routing models have been developed at Oak Ridge National Laboratory under the sponsorship of the U.S. Department of Energy (DOE). These models have been designated by DOE`s Office of Environmental Restoration and Waste Management, Transportation Management Division (DOE/EM) as the official DOE routing models. Both models, HIGHWAY and INTERLINE, are described.

Joy, D.S.; Johnson, P.E.

1994-06-01T23:59:59.000Z

53

Modeling Sea Ice Transport Using Incremental Remapping  

Science Conference Proceedings (OSTI)

Sea ice models contain transport equations for the area, volume, and energy of ice and snow in various thickness categories. These equations typically are solved with first-order-accurate upwind schemes, which are very diffusive; with second-...

William H. Lipscomb; Elizabeth C. Hunke

2004-06-01T23:59:59.000Z

54

Fuel Cell Technologies Office: Transport Modeling Working Group  

NLE Websites -- All DOE Office Websites (Extended Search)

Transport Modeling Transport Modeling Working Group to someone by E-mail Share Fuel Cell Technologies Office: Transport Modeling Working Group on Facebook Tweet about Fuel Cell Technologies Office: Transport Modeling Working Group on Twitter Bookmark Fuel Cell Technologies Office: Transport Modeling Working Group on Google Bookmark Fuel Cell Technologies Office: Transport Modeling Working Group on Delicious Rank Fuel Cell Technologies Office: Transport Modeling Working Group on Digg Find More places to share Fuel Cell Technologies Office: Transport Modeling Working Group on AddThis.com... Key Activities Plans, Implementation, & Results Accomplishments Organization Chart & Contacts Quick Links Hydrogen Production Hydrogen Delivery Hydrogen Storage Fuel Cells Technology Validation

55

Life-cycle assessment of corn-based butanol as a potential transportation fuel.  

Science Conference Proceedings (OSTI)

Butanol produced from bio-sources (such as corn) could have attractive properties as a transportation fuel. Production of butanol through a fermentation process called acetone-butanol-ethanol (ABE) has been the focus of increasing research and development efforts. Advances in ABE process development in recent years have led to drastic increases in ABE productivity and yields, making butanol production worthy of evaluation for use in motor vehicles. Consequently, chemical/fuel industries have announced their intention to produce butanol from bio-based materials. The purpose of this study is to estimate the potential life-cycle energy and emission effects associated with using bio-butanol as a transportation fuel. The study employs a well-to-wheels analysis tool--the Greenhouse Gases, Regulated Emissions and Energy Use in Transportation (GREET) model developed at Argonne National Laboratory--and the Aspen Plus{reg_sign} model developed by AspenTech. The study describes the butanol production from corn, including grain processing, fermentation, gas stripping, distillation, and adsorption for products separation. The Aspen{reg_sign} results that we obtained for the corn-to-butanol production process provide the basis for GREET modeling to estimate life-cycle energy use and greenhouse gas emissions. The GREET model was expanded to simulate the bio-butanol life cycle, from agricultural chemical production to butanol use in motor vehicles. We then compared the results for bio-butanol with those of conventional gasoline. We also analyzed the bio-acetone that is coproduced with bio-butanol as an alternative to petroleum-based acetone. Our study shows that, while the use of corn-based butanol achieves energy benefits and reduces greenhouse gas emissions, the results are affected by the methods used to treat the acetone that is co-produced in butanol plants.

Wu, M.; Wang, M.; Liu, J.; Huo, H.; Energy Systems

2007-12-31T23:59:59.000Z

56

World Energy Projection System Plus Model Documentation: Transportation Model  

Reports and Publications (EIA)

This report documents the objectives, analytical approach and development of the World Energy Projection System Plus (WEPS+) International Transportation model. It also catalogues and describes critical assumptions, computational methodology, parameter estimation techniques, and model source code.

Victoria Zaretskaya

2011-09-29T23:59:59.000Z

57

Canonical suppression in microscopic transport models  

E-Print Network (OSTI)

We demonstrate the occurrence of canonical suppression associated with the conservation of an U(1)-charge in current transport models. For this study a pion gas is simulated within two different transport approaches by incorporating inelastic and volume-limited collisions $\\pi\\pi\\leftrightarrow K\\bar{K}$ for the production of kaon pairs. Both descriptions can dynamically account for the suppression in the yields of rare strange particles in a limited box, being in full accordance with a canonical statistical description.

O. Fochler; S. Vogel; M. Bleicher; C. Greiner; P. Koch-Steinheimer; Z. Xu

2006-01-20T23:59:59.000Z

58

Transportation Sector Module 1997, Model Documentation  

Reports and Publications (EIA)

Over the past year, several modifications have been made to the NEMS Transportation Model,incorporating greater levels of detail and analysis in modules previously represented in the aggregate or under a profusion of simplifying assumptions. This document is intended to amend those sections of the Model Documentation Report (MDR) which describe these superseded modules.

John Maples

1997-02-01T23:59:59.000Z

59

Hydrogen recycle modeling in transport codes  

DOE Green Energy (OSTI)

The hydrogen recycling models now used in Tokamak transport codes are reviewed and the method by which realistic recycling models are being added is discussed. Present models use arbitrary recycle coefficients and therefore do not model the actual recycling processes at the wall. A model for the hydrogen concentration in the wall serves two purposes: (1) it allows a better understanding of the density behavior in present gas puff, pellet, and neutral beam heating experiments; and (2) it allows one to extrapolate to long pulse devices such as EBT, ISX-C and reactors where the walls are observed or expected to saturate. Several wall models are presently being studied for inclusion in transport codes.

Howe, H.C.

1979-01-01T23:59:59.000Z

60

Transportation Sector Module 1995 - Model Developer's Report, Model Documentation  

Reports and Publications (EIA)

As the description in Section 4 and Appendix B shows, the NEMS Transportation Model is made up of seven semi-independent submodules which address different vehicular modes of the transportation sector. Each submodule also contains methods to deal with the impacts of policyinitiatives and legislative mandates which affect individual modes of travel. The transportation sector energy consumption is the sum of the energy consumption forecasts generated through the separate submodules.

John Maples

1995-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "transportation greet model" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Climate Impact of Transportation A Model Comparison  

Science Conference Proceedings (OSTI)

Transportation contributes to a significant and rising share of global energy use and GHG emissions. Therefore modeling future travel demand, its fuel use, and resulting CO2 emission is highly relevant for climate change mitigation. In this study we compare the baseline projections for global service demand (passenger-kilometers, ton-kilometers), fuel use, and CO2 emissions of five different global transport models using harmonized input assumptions on income and population. For four models we also evaluate the impact of a carbon tax. All models project a steep increase in service demand over the century. Technology is important for limiting energy consumption and CO2 emissions, but quite radical changes in the technology mix are required to stabilize or reverse the trend. While all models project liquid fossil fuels dominating up to 2050, they differ regarding the use of alternative fuels (natural gas, hydrogen, biofuels, and electricity), because of different fuel price projections. The carbon tax of US$200/tCO2 in 2050 stabilizes or reverses global emission growth in all models. Besides common findings many differences in the model assumptions and projections indicate room for improvement in modeling and empirical description of the transport system.

Girod, Bastien; Van Vuuren, Detlef; Grahn, Maria; Kitous, Alban; Kim, Son H.; Kyle, G. Page

2013-06-01T23:59:59.000Z

62

E-model for Transportation Problem of Linear Stochastic Fractional ...  

E-Print Network (OSTI)

studied stochastic transportation model for petroleum transport as well ... homogenous commodity from m sources to n of destinations, where the demand for the.

63

Model Recovery Procedure for Response to a Radiological Transportation Incident  

Energy.gov (U.S. Department of Energy (DOE))

This Transportation Emergency Preparedness Program (TEPP) Model Recovery Procedure contains the recommended elements for developing and conducting recovery planning at transportation incident scene...

64

Impact of Transport Schemes on Modeled Dust Concentrations  

Science Conference Proceedings (OSTI)

A sensitivity study is performed with the CHIMERE-DUST chemistry transport model in order to evaluate the modeled mineral dust spread due to the horizontal transport scheme accuracy. Three different schemes are implemented in the model: the ...

Maria Raffaella Vuolo; Laurent Menut; Hlne Chepfer

2009-06-01T23:59:59.000Z

65

Modeling of nearshore hydrodynamics for sediment transport calculations  

E-Print Network (OSTI)

This thesis analyzes and improves Tajima's (2004) nearshore hydrodynamic model. Tajima's simple model accurately predicts long-shore sediment transport along long, straight beaches, while cross-shore transport predictions ...

Gonzalez-Rodriguez, David, Ph. D. Massachusetts Institute of Technology

2006-01-01T23:59:59.000Z

66

A Model for Long-Range Transport of Desert Dust  

Science Conference Proceedings (OSTI)

An Eulerian model for dust transport in the atmosphere is designed, and a new parameterization scheme for dust uptake is developed. The model results are quantitatively compared with satellite observations for an intense dust transport event that ...

Slobodan Ni?kovi?; Srdjan Dobri?i?

1996-11-01T23:59:59.000Z

67

Transportation Sector Module 2000 Vol 2, Model Documentation  

Reports and Publications (EIA)

Documents the objectives, analytical approach and development of the National Energy Modeling System (NEMS) Transportation Model (TRAN). The report catalogues and describes the model assumptions, computational methodology, parameter estimation techniques, model source code, and forecast results generated by the model.

John Maples

2000-01-01T23:59:59.000Z

68

Transportation Sector Module 2000 Vol 1, Model Documentation  

Reports and Publications (EIA)

Documents the objectives, analytical approach and development of the National Energy Modeling System (NEMS) Transportation Model (TRAN). The report catalogues and describes the model assumptions, computational methodology, parameter estimation techniques, model source code, and forecast results generated by the model.

John Maples

2000-01-01T23:59:59.000Z

69

Transportation Energy Model of the World Energy Projection System ...  

U.S. Energy Information Administration (EIA)

The WEPS Transportation Energy Model is a structural accounting model for road, rail, air, domestic shipping, international shipping, and pipeline energy use.

70

The Zonally Averaged Transport Characteristics of the GFDL General Circulation/Transport Model  

Science Conference Proceedings (OSTI)

The GFDL general circulation/tracer model has been used to generate the transport coefficients required in two-dimensional (zonally averaged) transport formulations. This was done by assuming a flux-gradient relationship and then, given gradient ...

R. A. Plumb; J. D. Mahlman

1987-01-01T23:59:59.000Z

71

A framework for modeling rail transport vulnerability  

Science Conference Proceedings (OSTI)

Railroads represent one of the most efficient methods of long-haul transport for bulk commodities, from coal to agricultural products. Over the past fifty years, the rail network has contracted while tonnage has increased. Service, geographically, has been abandoned along short haul routes and increased along major long haul routes, resulting in a network that is more streamlined. The current rail network may be very vulnerable to disruptions, like the failure of a trestle. This paper proposes a framework to model rail network vulnerability and gives an application of this modeling framework in analyzing rail network vulnerability for the State of Washington. It concludes with a number of policy related issues that need to be addressed in order to identify, plan, and mitigate the risks associated with the sudden loss of a bridge or trestle.

Peterson, Steven K [ORNL; Church, Richard L. [University of California, Santa Barbara

2008-01-01T23:59:59.000Z

72

Poleward Heat Transport in a Barotropic Ocean Model  

Science Conference Proceedings (OSTI)

A barotropic ocean circulation model coupled to a mixed-layer temperature equation is used to study the poleward heat transport by the horizontal wind-driven ocean currents. Through scaling analyses, two different regimes of the heat transport ...

Xiaoli Wang; Peter H. Stone; Jochem Marotzke

1995-02-01T23:59:59.000Z

73

8:00-8:30 Registration. Coffee 8:30-9:50 Opening Session. Chair E. Elias, Technion. Greetings by  

E-Print Network (OSTI)

Research) - Hiroshima & Nagasaki bombings: the radio-epidemiological aspect 10:50- 11:10 Y. Socol (AFNA. Greetings by representatives of Technion, Mechanical Engineering Faculty, Israel Atomic Energy Commission 9 nuclear threat 11:50-12:15 I. Levanon (Israel Atomic Energy Commission - IAEC)­ Threat from malicious acts

Rimon, Elon

74

Device Scale Model Development for Transport Reactor  

NLE Websites -- All DOE Office Websites (Extended Search)

Gary J. stiegel Gary J. stiegel Gasification Technology Manager National Energy Technology Laboratory 626 Cochrans Mill Road P.O. Box 10940 Pittsburgh, PA 15236 412-386-4499 gary.stiegel@netl.doe.gov Chris Guenther Computational Science Division National Energy Technology Laboratory 3610 Collins Ferry Road P. O. Box 880 Morgantown, WV 26507 304-285-4483 chris.guenther@netl.doe.gov 8/2006 Gasification Technologies Device Scale MoDel DevelopMent for tranSport reactor Background Coal gasification is an efficient and environmentally acceptable technology that can utilize the vast coal reserves in the United States to produce clean affordable power and reduce dependence on foreign oil. Coal and other carbon containing materials can be gasified to produce a synthesis gas. This syngas can be fed to a

75

On EOQ Cost Models with Arbitrary Purchase and Transportation ...  

E-Print Network (OSTI)

Abstract: We analyze an economic order quantity cost model with unit ... For the remaining purchase-transportation cost functions, when this problem becomes a ...

76

Water Transport in PEM Fuel Cells: Advanced Modeling, Material...  

NLE Websites -- All DOE Office Websites (Extended Search)

against * steady state and transient operational cell data. Complete fuel cell water transport model improvements * and code package development to include two phase flow....

77

Discrete second order adjoints in atmospheric chemical transport modeling  

Science Conference Proceedings (OSTI)

Atmospheric chemical transport models (CTMs) are essential tools for the study of air pollution, for environmental policy decisions, for the interpretation of observational data, and for producing air quality forecasts. Many air quality studies require ... Keywords: 65, Chemical transport models, Hessian singular vectors, Optimization, Second order adjoints, Sensitivity analysis, Stiff equations

Adrian Sandu; Lin Zhang

2008-06-01T23:59:59.000Z

78

A Review of Long-Range Transport Modeling  

Science Conference Proceedings (OSTI)

The various approaches to long-range transport modeling are outlined, and some of their virtues and shortcomings are discussed. Emphasis is put on models describing sulphur transport on the synoptic scale or from a few hundred up to 1000 km. Long-...

Anton Eliassen

1980-03-01T23:59:59.000Z

79

A Model for Transport across the Tropical Tropopause  

Science Conference Proceedings (OSTI)

A model of convective and advective transport across the tropical tropopause is described. In this model overshooting convective turrets inject dehydrated tropospheric air into a tropical tropopause layer (TTL) bounded approximately by the 50- ...

Steven C. Sherwood; Andrew E. Dessler

2001-04-01T23:59:59.000Z

80

An Eulerian Limited-Area Atmospheric Transport Model  

Science Conference Proceedings (OSTI)

A limited-area, offline, Eulerian atmospheric transport model has been developed. The model is based on a terrain-following vertical coordinate and a mass-conserving, positive definite advection scheme with small phase and amplitude errors. The ...

Lennart Robertson; Joakim Langner; Magnuz Engardt

1999-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "transportation greet model" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

A Small Aircraft Transportation System (SATS) Demand Model  

Science Conference Proceedings (OSTI)

The Small Aircraft Transportation System (SATS) demand modeling is a tool that will be useful for decision makers to analyze SATS demands in both airport and airspace. We constructed a series of models following the general top- down, modular principles ...

Long Dou; Lee David; Johnson Jesse; Kostiuk Peter

2001-06-01T23:59:59.000Z

82

Argonne Transportation Technology R&D Center - Lithium-ion Batteries,  

NLE Websites -- All DOE Office Websites (Extended Search)

Alternative Fuels Autonomie Batteries Downloadable Dynamometer Database Engines Green Racing GREET Hybrid Electric Vehicles Hydrogen & Fuel Cells Materials Modeling, Simulation & Software Plug-In Hybrid Electric Vehicles PSAT Smart Grid Student Competitions Technology Analysis Transportation Research and Analysis Computing Center Working With Argonne Contact TTRDC Photo of battery developers that links to story Press Coverage What's New Multimedia Logo of the Wharton School of Business Dec. 13. Knowledge@Wharton. Green SPorts and Transportation: The Elephant in the Room Logo of Crain's Chicago Business Dec. 10. Crain's Chicago Business. Argonne chemist Pete Chupas named one of Crain's 2013 "40 under 40" Logo of the Sioux City Journal Dec. 2. Sioux City Journal. Ethanol Supporters Say the Numbers Support Their Industry

83

Transportation Sector Module 1998 - Volume I, Model Documentation  

Reports and Publications (EIA)

This report documents the objectives, analytical approach and development of the National Energy Modeling System (NEMS) Transportation Model (TRAN). The report catalogues and describes the model assumptions, computational methodology, parameter estimation techniques, model source code, and forecast results generated by the model.

John Maples

1998-01-01T23:59:59.000Z

84

Modeling the impact of complexity on transportation  

E-Print Network (OSTI)

This thesis aimed to understand the drivers of total transportation costs during supply chain complexity events, in particular new product launches, in a fast moving consumer goods company in the United States. The research ...

Fernandez, Jose A. (Jose Antonio Fernandez Chavira)

2012-01-01T23:59:59.000Z

85

Modeling Arsenic Fate and Transport in Groundwater  

Science Conference Proceedings (OSTI)

The fate of arsenic in the environment depends on a variety of geochemical factors, including pH, oxidation and reduction potential, and the presence of competing solutes such as phosphates. Methods of predicting arsenic fate and transport are evolving to incorporate sophisticated geochemical simulations. While contaminant transport codes that utilize adsorption isotherm equations may be inadequate for arsenic prediction in certain cases, they may be very powerful tools in others. This report describes t...

2006-08-16T23:59:59.000Z

86

Modeling of concentrated aqueous solutions: Efficient implementation of Pitzer equations in geochemical and reactive transport models  

Science Conference Proceedings (OSTI)

Modeling concentrated solutions demands the use of ion-interaction models such as Pitzer equations, which involve a large number of operations. Implementation of these models in large reactive transport simulations significantly increases the computation ... Keywords: Concentrated solutions, Evaporation of seawater, Geochemical modeling, HMW model, Invariant points, Object-oriented programming, Pitzer, Reactive transport modeling

S. A. Bea; J. Carrera; C. Ayora; F. Batlle

2010-04-01T23:59:59.000Z

87

Fuel Cell Technologies Office: Transport Modeling Working Group  

NLE Websites -- All DOE Office Websites (Extended Search)

Transport Modeling Working Group Transport Modeling Working Group The Transport Modeling Working Group meets twice per year to exchange information, create synergies, share experimental and computational results, and collaboratively develop methodologies for and understanding of transport phenomena in polymer electrolyte fuel cell stacks. Its members include principle investigators and supporting personnel from transport-related projects funded by the U.S. Department of Energy (DOE). Learn more about DOE research activities can be found in the Multi-Year Research, Development, and Demonstration Plan. Description Technical Targets Meetings Contacts Description Fuel cell operation relies on effective mass transport of species through individual components and across the interfaces between components. Among these species are hydrogen, oxygen, water, protons, and electrons. Transport behavior is a function of operating conditions and component properties such as microstructure and surface properties. Understanding and optimizing the controlling transport phenomena are critical to the efficient and cost-effective operation of polymer electrolyte fuel cells. A better understanding of mass transport in the fuel cell, especially of water, has the potential to lead to improved designs and more efficient systems.

88

System of models for transport processes in layered strata  

Science Conference Proceedings (OSTI)

In this paper the normalized form of the generalized integral parabolic spline is described, which interpolates the integral averaged values of piecewise-smooth function. The three-dimensional system of partial differential equations as model of transport ... Keywords: conservative averaging, integral spline, layered media, three-dimensional, transport processes

Margarita Buike; Andris Buikis

2006-12-01T23:59:59.000Z

89

Hawking radiation via Landauer transport model  

E-Print Network (OSTI)

Recently, Nation et al confirmed that fluxes of Hawking radiation energy and entropy from a black hole can be regarded as a one-dimensional (1D) Landauer transport process. Their work can be extended to background spacetimes with gauge potential. The result shows that the energy flux, which is indicated to be equal to the energy-momentum tensor flux, contains not only the contribution of thermal flux but also that of particle flux. We find that the charge can also be regarded as transporting via a 1D quantum channel and the charge flux is equal to the gauge flux.

Xiao-Xiong Zeng; Wen-Biao Liu

2011-06-03T23:59:59.000Z

90

Airflow and Pollutant Transport Modeling In Indoor and Built...  

NLE Websites -- All DOE Office Websites (Extended Search)

Airflow and Pollutant Transport Modeling In Indoor and Built Environment Speaker(s): Teshome Edae Jiru Date: October 12, 2009 - 12:12pm Location: 90-3122 Computer simulation is...

91

Volcanic Ash Forecast Transport And Dispersion (VAFTAD) Model  

Science Conference Proceedings (OSTI)

The National Oceanic and Atmospheric Administration (NOAA) Air Resources Laboratory (ARL) has developed a Volcanic Ash Forecast Transport And Dispersion (VAFTAD) model for emergency response use focusing on hazards to aircraft flight operations. ...

Jerome L. Heffter; Barbara J. B. Stunder

1993-12-01T23:59:59.000Z

92

A Compositional Mathematical Model of Machines Transporting Rigid Objects  

Science Conference Proceedings (OSTI)

We present models of various elements of a plant that involves the transportation of lumped material. An application context is provided by a project on diagnosing disturbances in food packaging plants and, more specifically, bottling plants. While there ...

Peter Struss; Axel Kather; Dominik Schneider; Tobias Voigt

2008-06-01T23:59:59.000Z

93

Factors Affecting Heat Transport in an Ocean General Circulation Model  

Science Conference Proceedings (OSTI)

A global ocean general circulation model with idealized geometry and coupled to a simple representation of atmospheric energy fluxes is used to investigate which physical factors determine meridional heat transport. A particular focus is on ...

Igor Kamenkovich; Jochem Marotzke; Peter H. Stone

2000-01-01T23:59:59.000Z

94

Singular Vector Analysis for Atmospheric Chemical Transport Models  

Science Conference Proceedings (OSTI)

The singular vectors of a chemical transport model are the directions of maximum perturbation growth over a finite time interval. They have proved useful for the estimation of error growth, the initialization of ensemble forecasts, and the ...

Wenyuan Liao; Adrian Sandu; Gregory R. Carmichael; Tianfeng Chai

2006-09-01T23:59:59.000Z

95

What Determines Meridional Heat Transport in Climate Models?  

Science Conference Proceedings (OSTI)

The annual mean maximum meridional heat transport (MHTMAX) differs by approximately 20% among coupled climate models. The value of MHTMAX can be expressed as the difference between the equator-to-pole contrast in absorbed solar radiation (ASR*) ...

Aaron Donohoe; David S. Battisti

2012-06-01T23:59:59.000Z

96

Statistical modelling of delays in a rail freight transportation network  

Science Conference Proceedings (OSTI)

This study analyzes the transportation network of a major rail freight operator in order to obtain a model of delay propagation of trains connecting intermodal terminals. Operational management of a rail freight operator needs to take into account deviations ...

Jnos Barta; Andrea Emilio Rizzoli; Matteo Salani; Luca Maria Gambardella

2012-12-01T23:59:59.000Z

97

Decision-making models for reproducing intelligence in transportation...  

NLE Websites -- All DOE Office Websites (Extended Search)

Decision-making models for reproducing intelligence in transportation January 01, 2013 It could be the start of a good riddle: How many syn-apses of the brain does it take to...

98

Modeling and Simulation - Center for Transportation Analysis  

NLE Websites -- All DOE Office Websites (Extended Search)

and route airlift (CAMPS), and key components for the Department of Energy's National Energy Modeling System. We have designed and developed models for personal computers,...

99

Transportation Sector Model of the National Energy Modeling System. Volume 2 -- Appendices: Part 1  

Science Conference Proceedings (OSTI)

This volume contains input data and parameters used in the model of the transportation sector of the National Energy Modeling System. The list of Transportation Sector Model variables includes parameters for the following: Light duty vehicle modules (fuel economy, regional sales, alternative fuel vehicles); Light duty vehicle stock modules; Light duty vehicle fleet module; Air travel module (demand model and fleet efficiency model); Freight transport module; Miscellaneous energy demand module; and Transportation emissions module. Also included in these appendices are: Light duty vehicle market classes; Maximum light duty vehicle market penetration parameters; Aircraft fleet efficiency model adjustment factors; and List of expected aircraft technology improvements.

NONE

1998-01-01T23:59:59.000Z

100

Solids transportation model of an industrial rotary dryer  

SciTech Connect

A complete simulation model has been developed for an industrial rotary dryer to account for the heat and mass exchange between the solids and the gas. This simulator is mainly composed of three models: solids transportation model, furnace model, and gas model. The solids transportation model is the modified Cholette-Cloutier model. It consists of a series of interactive reservoirs which are subdivided into an active and dead compartments to account for the characteristic extended tail of the residence time distribution (RTD) curves observed in industrial dryers. To expand the validity of the model, experiments have been performed in an industrial rotary dryer to obtain RTD curves under different mineral concentrate and gas flow rates. This paper describes these experiments and presents the variation of the average residence time and model parameters as function of solids and gas flow rates.

Renaud, M.; Thibault, J.; Trusiak, A.

2000-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "transportation greet model" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Chemical Kinetic Modeling of Advanced Transportation Fuels  

DOE Green Energy (OSTI)

Development of detailed chemical kinetic models for advanced petroleum-based and nonpetroleum based fuels is a difficult challenge because of the hundreds to thousands of different components in these fuels and because some of these fuels contain components that have not been considered in the past. It is important to develop detailed chemical kinetic models for these fuels since the models can be put into engine simulation codes used for optimizing engine design for maximum efficiency and minimal pollutant emissions. For example, these chemistry-enabled engine codes can be used to optimize combustion chamber shape and fuel injection timing. They also allow insight into how the composition of advanced petroleum-based and non-petroleum based fuels affect engine performance characteristics. Additionally, chemical kinetic models can be used separately to interpret important in-cylinder experimental data and gain insight into advanced engine combustion processes such as HCCI and lean burn engines. The objectives are: (1) Develop detailed chemical kinetic reaction models for components of advanced petroleum-based and non-petroleum based fuels. These fuels models include components from vegetable-oil-derived biodiesel, oil-sand derived fuel, alcohol fuels and other advanced bio-based and alternative fuels. (2) Develop detailed chemical kinetic reaction models for mixtures of non-petroleum and petroleum-based components to represent real fuels and lead to efficient reduced combustion models needed for engine modeling codes. (3) Characterize the role of fuel composition on efficiency and pollutant emissions from practical automotive engines.

PItz, W J; Westbrook, C K; Herbinet, O

2009-01-20T23:59:59.000Z

102

A fracture network model for water flow and solute transport  

DOE Green Energy (OSTI)

This paper summarizes code development work and sample calculations for FRACNET, a two-dimensional steady state simulator of fluid flow and solute transport in fractured porous media. The model analyzes flow and transport by generating a fracture network based on statistical characteristics of fractures obtained from well logs and other data. After a network is generated, flow and tracer transport are computed for appropriate boundary conditions and wellbore source/sink terms. In addition, for a given realization, the code can be used to indicate whether the medium can be treated as an equivalent porous medium. 18 refs., 7 figs.

Robinson, B.A.

1989-01-01T23:59:59.000Z

103

Generating seamless surfaces for transport and dispersion modeling in GIS  

Science Conference Proceedings (OSTI)

A standard use of triangulation in GIS is to model terrain surface using TIN. In many simulation models of physical phenomena, triangulation is often used to depict the entire spatial domain, which may include buildings, landmarks and other surface objects ... Keywords: CAD, Computational fluid dynamics, Computational geometry, GIS, Mesh generation, Transport and dispersion

Fernando Camelli; Jyh-Ming Lien; Dayong Shen; David W. Wong; Matthew Rice; Rainald Lhner; Chaowei Yang

2012-04-01T23:59:59.000Z

104

Multimodal accessibility modeling from coarse transportation networks in Africa  

Science Conference Proceedings (OSTI)

Accessibility is a key driving factor for economic development, social welfare, resources management, and land use planning. In many studies, modeling accessibility relies on proxy variables such as estimated travel time to selected destinations. In ... Keywords: African countries, coarse transportation networks, multimodal travel-time modeling, travel-time surface

Jean-Paul Kibambe Lubamba, Julien Radoux, Pierre Defourny

2013-05-01T23:59:59.000Z

105

Physics models in the toroidal transport code PROCTR  

DOE Green Energy (OSTI)

The physics models that are contained in the toroidal transport code PROCTR are described in detail. Time- and space-dependent models are included for the plasma hydrogenic-ion, helium, and impurity densities, the electron and ion temperatures, the toroidal rotation velocity, and the toroidal current profile. Time- and depth-dependent models for the trapped and mobile hydrogenic particle concentrations in the wall and a time-dependent point model for the number of particles in the limiter are also included. Time-dependent models for neutral particle transport, neutral beam deposition and thermalization, fusion heating, impurity radiation, pellet injection, and the radial electric potential are included and recalculated periodically as the time-dependent models evolve. The plasma solution is obtained either in simple flux coordinates, where the radial shift of each elliptical, toroidal flux surface is included to maintain an approximate pressure equilibrium, or in general three-dimensional torsatron coordinates represented by series of helical harmonics. The detailed coupling of the plasma, scrape-off layer, limiter, and wall models through the neutral transport model makes PROCTR especially suited for modeling of recycling and particle control in toroidal plasmas. The model may also be used in a steady-state profile analysis mode for studying energy and particle balances starting with measured plasma profiles.

Howe, H.C.

1990-08-01T23:59:59.000Z

106

The National Energy Modeling System: An Overview 2000 - Transportation  

Gasoline and Diesel Fuel Update (EIA)

transportation demand module (TRAN) forecasts the consumption of transportation sector fuels by transportation mode, including the use of renewables and alternative fuels, subject to delivered prices of energy fuels and macroeconomic variables, including disposable personal income, gross domestic product, level of imports and exports, industrial output, new car and light truck sales, and population. The structure of the module is shown in Figure 8. transportation demand module (TRAN) forecasts the consumption of transportation sector fuels by transportation mode, including the use of renewables and alternative fuels, subject to delivered prices of energy fuels and macroeconomic variables, including disposable personal income, gross domestic product, level of imports and exports, industrial output, new car and light truck sales, and population. The structure of the module is shown in Figure 8. Figure 8. Transportation Demand Module Structure NEMS projections of future fuel prices influence the fuel efficiency, vehicle-miles traveled, and alternative-fuel vehicle (AFV) market penetration for the current fleet of vehicles. Alternative-fuel shares are projected on the basis of a multinomial logit vehicle attribute model, subject to State and Federal government mandates.

107

Gas transport model for chemical vapor infiltration  

Science Conference Proceedings (OSTI)

A node-bond percolation model is presented for the gas permeability and pore surface area of the coarse porosity in woven fiber structures during densification by chemical vapor infiltration (CVI). Model parameters include the number of nodes per unit volume and their spatial distribution, and the node and bond radii and their variability. These parameters relate directly to structural features of the weave. Some uncertainty exists in the proper partition of the porosity between ``node`` and ``bond`` and between intra-tow and inter-tow, although the total is constrained by the known fiber loading in the structure. Applied to cloth layup preforms the model gives good agreement with the limited number of available measurements.

Starr, T.L. [School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0245 (United States)

1995-09-01T23:59:59.000Z

108

Agent-Based Modeling of Intracellular Transport  

E-Print Network (OSTI)

We develop an agent-based model of the motion and pattern formation of vesicles. These intracellular particles can be found in four different modes of (undirected and directed) motion and can fuse with other vesicles. While the size of vesicles follows a log-normal distribution that changes over time due to fusion processes, their spatial distribution gives rise to distinct patterns. Their occurrence depends on the concentration of proteins which are synthesized based on the transcriptional activities of some genes. Hence, differences in these spatio-temporal vesicle patterns allow indirect conclusions about the (unknown) impact of these genes. By means of agent-based computer simulations we are able to reproduce such patterns on real temporal and spatial scales. Our modeling approach is based on Brownian agents with an internal degree of freedom, $\\theta$, that represents the different modes of motion. Conditions inside the cell are modeled by an effective potential that differs for agents dependent on their...

Birbaumer, Mirko; 10.1140/epjb/e2011-20283-x

2011-01-01T23:59:59.000Z

109

Modeling studies of mountain-scale radionuclide transport in the unsaturated zone at Yucca Mountain, Nevada  

E-Print Network (OSTI)

Wu, and G.S. Bodvarsson, Radionuclide Transport Models Underdaughters of certain radionuclides. Increasing infiltrationOF MOUNTAIN-SCALE RADIONUCLIDE TRANSPORT IN THE UNSATURATED

Moridis, George J.; Seol, Yongkoo; Wu, Yu-Shu

2003-01-01T23:59:59.000Z

110

Mass-Consistent Wind Model as a Meteorological Preprocessor for Tracer Transport Models  

Science Conference Proceedings (OSTI)

Atmospheric transport models usually require the mass conservation of the advective meteorological field. Even if the advection field is provided by sophisticated initialization or prediction models of meteorological centers, some mass imbalance ...

Hirohiko Ishikawa

1994-06-01T23:59:59.000Z

111

Some Effects of Different Cloud Parameterizations in a Mesoscale Model and a Chemistry Transport Model  

Science Conference Proceedings (OSTI)

Chemistry transport models often ignore the cloud parameters that can be provided by meteorological pre-processors like mesoscale meteorological models. They often recalculate these parameters with algorithms that differ from those used in the ...

Nicole Mlders; Heinz Hass; Hermann J. Jakobs; Manfred Laube; Adolf Ebel

1994-04-01T23:59:59.000Z

112

Multiscale modeling for fluid transport in nanosystems.  

SciTech Connect

Atomistic-scale behavior drives performance in many micro- and nano-fluidic systems, such as mircrofludic mixers and electrical energy storage devices. Bringing this information into the traditionally continuum models used for engineering analysis has proved challenging. This work describes one such approach to address this issue by developing atomistic-to-continuum multi scale and multi physics methods to enable molecular dynamics (MD) representations of atoms to incorporated into continuum simulations. Coupling is achieved by imposing constraints based on fluxes of conserved quantities between the two regions described by one of these models. The impact of electric fields and surface charges are also critical, hence, methodologies to extend finite-element (FE) MD electric field solvers have been derived to account for these effects. Finally, the continuum description can have inconsistencies with the coarse-grained MD dynamics, so FE equations based on MD statistics were derived to facilitate the multi scale coupling. Examples are shown relevant to nanofluidic systems, such as pore flow, Couette flow, and electric double layer.

Lee, Jonathan W.; Jones, Reese E.; Mandadapu, Kranthi Kiran; Templeton, Jeremy Alan; Zimmerman, Jonathan A.

2013-09-01T23:59:59.000Z

113

Analytical model for flux saturation in sediment transport  

E-Print Network (OSTI)

The transport of sediment by a fluid along the surface is responsible for dune formation, dust entrainment and for a rich diversity of patterns on the bottom of oceans, rivers, and planetary surfaces. Most previous models of sediment transport have focused on the equilibrium (or saturated) particle flux. However, the morphodynamics of sediment landscapes emerging due to surface transport of sediment is controlled by situations out-of-equilibrium. In particular, it is controlled by the saturation length characterizing the distance it takes for the particle flux to reach a new equilibrium after a change in flow conditions. The saturation of mass density of particles entrained into transport and the relaxation of particle and fluid velocities constitute the main relevant relaxation mechanisms leading to saturation of the sediment flux. Here we present a theoretical model for sediment transport which, for the first time, accounts for both these relaxation mechanisms and for the different types of sediment entrainment prevailing under different environmental conditions. Our analytical treatment allows us to derive a closed expression for the saturation length of sediment flux, which is general and can thus be applied under different physical conditions.

T. Phtz; J. F. Kok; E. J. R. Parteli; H. J. Herrmann

2012-12-13T23:59:59.000Z

114

Airflow and Pollutant Transport Modeling In Indoor and Built Environment  

NLE Websites -- All DOE Office Websites (Extended Search)

Airflow and Pollutant Transport Modeling In Indoor and Built Environment Airflow and Pollutant Transport Modeling In Indoor and Built Environment Speaker(s): Teshome Edae Jiru Date: October 12, 2009 - 12:12pm Location: 90-3122 Computer simulation is based on mathematical models developed mostly from theoretical science and helps for studying and prediction of the behavior of engineered systems. The advantages of computer simulation are the ease of varying the desired parameters to investigate various possible design scenarios, explore new theories, and design new experiments to test these theories. It also provides detailed information and serves as a powerful alternative to experimental science and observation when phenomena are not observable or when measurements are impractical or too expensive. This seminar presents the different types of mechanistic modeling approaches

115

Model documentation report: Transportation sector model of the National Energy Modeling System  

SciTech Connect

This report documents the objectives, analytical approach and development of the National Energy Modeling System (NEMS) Transportation Model (TRAN). The report catalogues and describes the model assumptions, computational methodology, parameter estimation techniques, model source code, and forecast results generated by the model. This document serves three purposes. First, it is a reference document providing a detailed description of TRAN for model analysts, users, and the public. Second, this report meets the legal requirements of the Energy Information Administration (EIA) to provide adequate documentation in support of its statistical and forecast reports (Public Law 93-275, 57(b)(1)). Third, it permits continuity in model development by providing documentation from which energy analysts can undertake model enhancements, data updates, and parameter refinements.

Not Available

1994-03-01T23:59:59.000Z

116

U.S. OpenLabs - Climate Change | Open Energy Information  

Open Energy Info (EERE)

Gas Analysis 2005 Baseline Model The Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation Model (GREET) Transparent Cost Database Retrieved from...

117

Greenhouse Gases, Regulated Emissions, and Energy Use in Transportatio...  

Open Energy Info (EERE)

Regulated Emissions, and Energy Use in Transportation (GREET) Model Abstract This full life-cycle model evaluates the energy and emission impacts of advanced vehicle technologies...

118

Sediment and radionuclide transport in rivers: radionuclide transport modeling for Cattaraugus and Buttermilk Creeks, New York  

Science Conference Proceedings (OSTI)

SERATRA, a transient, two-dimensional (laterally-averaged) computer model of sediment-contaminant transport in rivers, satisfactorily resolved the distribution of sediment and radionuclide concentrations in the Cattaraugus Creek stream system in New York. By modeling the physical processes of advection, diffusion, erosion, deposition, and bed armoring, SERATRA routed three sediment size fractions, including cohesive soils, to simulate three dynamic flow events. In conjunction with the sediment transport, SERATRA computed radionuclide levels in dissolved, suspended sediment, and bed sediment forms for four radionuclides (/sup 137/Cs, /sup 90/Sr, /sup 239/ /sup 240/Pu, and /sup 3/H). By accounting for time-dependent sediment-radionuclide interaction in the water column and bed, SERATA is a physically explicit model of radionuclide fate and migration. Sediment and radionuclide concentrations calculated by SERATA in the Cattaraugus Creek stream system are in reasonable agreement with measured values. SERATRA is in the field performance phase of an extensive testing program designed to establish the utility of the model as a site assessment tool. The model handles not only radionuclides but other contaminants such as pesticides, heavy metals and other toxic chemicals. Now that the model has been applied to four field sites, including the latest study of the Cattaraugus Creek stream system, it is recommended that a final model be validated through comparison of predicted results with field data from a carefully controlled tracer test at a field site. It is also recommended that a detailed laboratory flume be tested to study cohesive sediment transport, deposition, and erosion characteristics. The lack of current understanding of these characteristics is one of the weakest areas hindering the accurate assessment of the migration of radionuclides sorbed by fine sediments of silt and clay.

Onishi, Y.; Yabusaki, S.B.; Kincaid, C.T.; Skaggs, R.L.; Walters, W.H.

1982-12-01T23:59:59.000Z

119

Transportation  

NLE Websites -- All DOE Office Websites (Extended Search)

Transportation banner Home Agenda Awards Exhibitors Lodging Posters Registration T-Shirt Contest Transportation Workshops Contact Us User Meeting Archives Users' Executive...

120

Transportation  

NLE Websites -- All DOE Office Websites (Extended Search)

Transportation Print banner Home Agenda Awards Exhibitors Lodging Posters Registration T-Shirt Contest Transportation Workshops Contact Us User Meeting Archives Users' Executive...

Note: This page contains sample records for the topic "transportation greet model" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Transportation  

NLE Websites -- All DOE Office Websites (Extended Search)

Links Transportation and Air Quality Transportation Energy Policy Analysis Batteries and Fuel Cells Buildings Energy Efficiency Electricity Grid Energy Analysis Appliance Energy...

122

Fuel-Cycle Analysis of Hydrogen-Powered Fuel-Cell Systems with the GREET Model  

E-Print Network (OSTI)

W gasoline SOFC technology development program APU applications can provide entry markets for fuel cell & Select APU Systems 2 · Summarize PEM and SOFC performance parameters · Determine most promising future Task 3: Develop design concepts · Truck Cab/SOFC/diesel · Transit bus/SOFC/CNG or diesel · Police

123

Introduction toIntroduction to GREET1.8 Excel Model  

E-Print Network (OSTI)

.8 (Cont'd.) NG: Calculations of well-to-pump energy use and emissions for NG-based fuels (plus flared gas:NA NG Central Plant Production: Central Plant Production: NNA Flared Gas NA NG NNA NG Central Plant-Generation Electric Co-Generation Distributed Production Gaseous H2 Liquid H2 NNA Flared Gas NA NG NNA NG Central

Argonne National Laboratory

124

COMPARISON OF RF CAVITY TRANSPORT MODELS FOR BBU SIMULATIONS  

Science Conference Proceedings (OSTI)

The transverse focusing effect in RF cavities plays a considerable role in beam dynamics for low-energy beamline sections and can contribute to beam breakup (BBU) instability. The purpose of this analysis is to examine RF cavity models in simulation codes which will be used for BBU experiments at Jefferson Lab and improve BBU simulation results. We review two RF cavity models in the simulation codes elegant and TDBBU (a BBU simulation code developed at Jefferson Lab). elegant can include the Rosenzweig-Serafini (R-S) model for the RF focusing effect. Whereas TDBBU uses a model from the code TRANSPORT which considers the adiabatic damping effect, but not the RF focusing effect. Quantitative comparisons are discussed for the CEBAF beamline. We also compare the R-S model with the results from numerical simulations for a CEBAF-type 5-cell superconducting cavity to validate the use of the R-S model as an improved low-energy RF cavity transport model in TDBBU. We have implemented the R-S model in TDBBU. It will improve BBU simulation results to be more matched with analytic calculations and experimental results.

Ilkyoung Shin,Byung Yunn,Todd Satogata,Shahid Ahmed

2011-03-01T23:59:59.000Z

125

A hybrid model for particle transport and electron energy distributions in positive column electrical discharges using equivalent species transport  

E-Print Network (OSTI)

A hybrid model for particle transport and electron energy distributions in positive column the fluid portion of the model. Transport coefficients, source functions, and energy distributions for all field has motivated a num- ber of investigations into its effect on the `electron energy distribution

Kushner, Mark

126

Argonne Transportation - 2005 R&D Award  

NLE Websites -- All DOE Office Websites (Extended Search)

GREETing a Cleaner, More Energy-Efficient Future GREETing a Cleaner, More Energy-Efficient Future With gas prices soaring, the fuel and vehicle options open to Americans are more varied than ever. But what fuel and vehicle combination provides the lowest total emissions with the highest energy efficiency? Researchers at Argonne's Center for Transportation Research (CTR) have been studying these questions and others for a quarter of century and have developed software that is now the government and industry standard for evaluating various vehicle and fuel combinations on a consistent fuel-cycle basis from extracting the energy feedstocks -petroleum and natural gas - through fuel production to final vehicle operation. Called GREET- for Greenhouse gases, Regulated Emissions and Energy use in Transportation - the software "evaluates the energy and emission facts from the beginning of the whole process," explained Michael Wang, section leader for Systems Assessment. "For gasoline, the fuel cycle starts with petroleum recovery, followed by petroleum transportation, refining to produce gasoline, transportation, and distribution to refueling stations, and finally gasoline used in vehicles."

127

Transportation  

NLE Websites -- All DOE Office Websites (Extended Search)

Transportation Transportation Transportation of Depleted Uranium Materials in Support of the Depleted Uranium Hexafluoride Conversion Program Issues associated with transport of depleted UF6 cylinders and conversion products. Conversion Plan Transportation Requirements The DOE has prepared two Environmental Impact Statements (EISs) for the proposal to build and operate depleted uranium hexafluoride (UF6) conversion facilities at its Portsmouth and Paducah gaseous diffusion plant sites, pursuant to the National Environmental Policy Act (NEPA). The proposed action calls for transporting the cylinder at ETTP to Portsmouth for conversion. The transportation of depleted UF6 cylinders and of the depleted uranium conversion products following conversion was addressed in the EISs.

128

A fractional dispersion model for overland solute transport  

E-Print Network (OSTI)

Using the kinematic-wave overland flow equation and a fractional dispersion-advection equation, a process-oriented, physically-based model is developed for overland solute transport. Two scenarios, one consisting of downslope and the other of upslope rainstorm movements, are considered for numerical computations. Under these conditions, the hydrograph displays a long-tailed distribution due to the variation in flow velocity in both time and distance. The solute transport exhibits a complex behavior. Pollutographs are characterized by a steep rising limb, with a peak, and a long, stretched receding limb; whereas the solute concentration distributions feature a rapid receding limb followed by a long stretched rising limb. Downslope moving storms cause much higher peak in both hydrographs and pollutographs than do upslope moving storms. Both hydrographs and the pollutographs predicted by the fractional dispersion model are in good agreement with the data measured experimentally using a soil flume and a moving rainfall simulator.

Deng, Zhi-Qiang; de Lima, M. Isabel P.; Singh, Vijay P.; de Lima, Jo??o L. M. P.

2006-03-18T23:59:59.000Z

129

A numerical model simulation of longshore transport for Galveston Island  

E-Print Network (OSTI)

The shoreline changes, deposition patterns, and longshore transport rates were calculated for the coast of Galveston Island using a numerical model simulation. The model only simulated changes due to waves creating longshore currents. East Beach showed a net accretion pattern, with erosion confined to the eastern section of the area. Large accretion was found near the first groin indicating transport from east to west. The groin field fluctuated with erosion and accretion, with a net gain of shoreline. The unprotected beach in front of the seawall eroded almost completely away. West Beach had a net loss of shoreline overall. This was largely due to the shoreline erosion found at San Luis Pass. The majority of West Beach was frequently unstable, fluctuating between erosion and accretion.

Gilbreath, Stephen Alexander

1995-01-01T23:59:59.000Z

130

Lessons Learned from Alternative Transportation Fuels: Modeling Transition Dynamics  

Alternative Fuels and Advanced Vehicles Data Center (EERE)

Lessons Learned from Lessons Learned from Alternative Transportation Fuels: Modeling Transition Dynamics C. Welch Technical Report NREL/TP-540-39446 February 2006 Lessons Learned from Alternative Transportation Fuels: Modeling Transition Dynamics C. Welch Prepared under Task Nos. HS04.2000 and HS06.1002 Technical Report NREL/TP-540-39446 February 2006 National Renewable Energy Laboratory 1617 Cole Boulevard, Golden, Colorado 80401-3393 303-275-3000 * www.nrel.gov Operated for the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy by Midwest Research Institute * Battelle Contract No. DE-AC36-99-GO10337 NOTICE This report was prepared as an account of work sponsored by an agency of the United States government. Neither the United States government nor any agency thereof, nor any of their employees, makes any

131

Modeling of contaminant transport in underground coal gasification  

Science Conference Proceedings (OSTI)

In order to study and discuss the impact of contaminants produced from underground coal gasification on groundwater, a coupled seepage-thermodynamics-transport model for underground gasification was developed on the basis of mass and energy conservation and pollutant-transport mechanisms, the mathematical model was solved by the upstream weighted multisell balance method, and the model was calibrated and verified against the experimental site data. The experiment showed that because of the effects of temperature on the surrounding rock of the gasification panel the measured pore-water-pressure was higher than the simulated one; except for in the high temperature zone where the simulation errors of temperature, pore water pressure, and contaminant concentration were relatively high, the simulation values of the overall gasification panel were well fitted with the measured values. As the gasification experiment progressed, the influence range of temperature field expanded, the gradient of groundwater pressure decreased, and the migration velocity of pollutant increased. Eleven months and twenty months after the test, the differences between maximum and minimum water pressure were 2.4 and 1.8 MPa, respectively, and the migration velocities of contaminants were 0.24-0.38 m/d and 0.27-0.46 m/d, respectively. It was concluded that the numerical simulation of the transport process for pollutants from underground coal gasification was valid. 42 refs., 13 figs., 1 tab.

Lanhe Yang; Xing Zhang [China University of Mining and Technology, Xuzhou (China). College of Resources and Geosciences

2009-01-15T23:59:59.000Z

132

Model Development and Analysis of the Fate and Transport of Water...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Model Development and Analysis of the Fate and Transport of Water in a Salt Based Repository Model Development and Analysis of the Fate and Transport of Water in a Salt Based...

133

A Lagrangian Long-Range Transport Model with Atmospheric Boundary Layer Chemistry  

Science Conference Proceedings (OSTI)

The present paper reports on the combination of a chemical model for the gas phase chemistry of the atmospheric boundary layer, with a Lagrangian model for the long-range transport of air pollutants. The resulting combined chemistry/transport ...

Anton Eliassen; Jrgen Saltbones; Frode Stordal; ystein Hov; Ivar S. A. Isaksen; Frode Stordal

1982-11-01T23:59:59.000Z

134

3-D numerical modelling of coastal currents and suspended sediment transport  

Science Conference Proceedings (OSTI)

A three dimensional hydrodynamic and suspended sediment transport model (HYDROTAM-3) has been developed and applied to Fethiye Bay. Model can simulate the transport processes due to tidal or nontidal forcing which may be barotropic or baroclinic. The ...

Lale Balas; Alp Kkosmano?lu; Umut Yegl

2006-05-01T23:59:59.000Z

135

Radiation transport phenomena and modeling - part A: Codes  

Science Conference Proceedings (OSTI)

The need to understand how particle radiation (high-energy photons and electrons) from a variety of sources affects materials and electronics has motivated the development of sophisticated computer codes that describe how radiation with energies from 1.0 keV to 100.0 GeV propagates through matter. Predicting radiation transport is the necessary first step in predicting radiation effects. The radiation transport codes that are described here are general-purpose codes capable of analyzing a variety of radiation environments including those produced by nuclear weapons (x-rays, gamma rays, and neutrons), by sources in space (electrons and ions) and by accelerators (x-rays, gamma rays, and electrons). Applications of these codes include the study of radiation effects on electronics, nuclear medicine (imaging and cancer treatment), and industrial processes (food disinfestation, waste sterilization, manufacturing.) The primary focus will be on coupled electron-photon transport codes, with some brief discussion of proton transport. These codes model a radiation cascade in which electrons produce photons and vice versa. This coupling between particles of different types is important for radiation effects. For instance, in an x-ray environment, electrons are produced that drive the response in electronics. In an electron environment, dose due to bremsstrahlung photons can be significant once the source electrons have been stopped.

Lorence, L.J.

1997-06-01T23:59:59.000Z

136

Transportation  

NLE Websites -- All DOE Office Websites (Extended Search)

Health Risks » Transportation Health Risks » Transportation DUF6 Health Risks line line Accidents Storage Conversion Manufacturing Disposal Transportation Transportation A discussion of health risks associated with transport of depleted UF6. Transport Regulations and Requirements In the future, it is likely that depleted uranium hexafluoride cylinders will be transported to a conversion facility. For example, it is currently anticipated that the cylinders at the ETTP Site in Oak Ridge, TN, will be transported to the Portsmouth Site, OH, for conversion. Uranium hexafluoride has been shipped safely in the United States for over 40 years by both truck and rail. Shipments of depleted UF6 would be made in accordance with all applicable transportation regulations. Shipment of depleted UF6 is regulated by the

137

Transportation Sector Module 1998 - Volume 2, Model Documentation  

Reports and Publications (EIA)

This appendix provides a detailed mathematical description of the transportation model. Equationsare presented in the order in which they are encountered in the code, identified by subroutine and model component. The equations follow the logic of the FORTRAN source code very closely to facilitate an understanding of the code and its structure. In several instances, a variable name will appear on both sides of an equation. This is a FORTRAN programming device t hat allows a previouscalculation to be updated (for example, multiplied by a factor) and re-stored under the same variable name.

John Maples

1998-01-01T23:59:59.000Z

138

Stochastic Models for Transport in a Fluidized Bed  

E-Print Network (OSTI)

In this paper we study stochastic models for the transport of particles in a fluidized bed reactor, and compute the associated residence time distribution (RTD). Our main model is basically a diffusion process in [0; A] with reflecting/absorbing boundary conditions, modified by allowing jumps to the origin as a result of transport of particles in the wake of rising fluidization bubbles. We study discrete time birth-death Markov chains as approximations to our diffusion model. For these we can compute the particle distribution inside the reactor as well as the RTD by simple and fast matrix calculations. It turns out that discretization of the reactor into a moderate number of segments already gives excellent numerical approximations to the continuous model. From the forward equation for the particle distribution in the discrete model we obtain in the diffusion limit a partial differential equation for the particle density p(t; x) @ @t p(t; x) = 1 2 @ 2 @x 2 [D(x)p(t; x)] \\Gamma @ @...

H. G. Dehling; A. C. Hoffmann; H. W. Stuut

1998-01-01T23:59:59.000Z

139

The importance of transport parameter cross correlations in natural systems radioactive transport models  

Science Conference Proceedings (OSTI)

Transport parameter cross correlations are rarely considered in models used to predict radionuclide transport in natural systems. In this paper, it is shown that parameter cross correlations could have a significant impact on radionuclide transport predictions in saturated media. In fractured rock, the positive correlation between fracture apertures and groundwater residence times is shown to result in significantly less retardation due to matrix diffusion than is predicted without the correlation. The suppression of matrix diffusion is further amplified by a tendency toward larger apertures, smaller matrix diffusion coefficients, and less sorption capacity in rocks of lower matrix porosity. In a hypothetical example, strong cross correlations between these parameters result in a decrease in predicted radionuclide travel times of an order of magnitude or more relative to travel times calculated with uncorrelated parameters. In porous media, expected correlations between permeability, porosity, and sorption capacity also result in shorter predicted travel times than when the parameters are assumed to be uncorrelated. Individual parameter standard deviations can also have a significant influence on predicted radionuclide travel times, particularly when cross correlations are considered.

Reimus, Paul W [Los Alamos National Laboratory

2011-01-03T23:59:59.000Z

140

Building 235-F Goldsim Fate And Transport Model  

Science Conference Proceedings (OSTI)

Savannah River National Laboratory (SRNL) personnel, at the request of Area Completion Projects (ACP), evaluated In-Situ Disposal (ISD) alternatives that are under consideration for deactivation and decommissioning (D&D) of Building 235-F and the Building 294-2F Sand Filter. SRNL personnel developed and used a GoldSim fate and transport model, which is consistent with Musall 2012, to evaluate relative to groundwater protection, ISD alternatives that involve either source removal and/or the grouting of portions or all of 235-F. This evaluation was conducted through the development and use of a Building 235-F GoldSim fate and transport model. The model simulates contaminant release from four 235-F process areas and the 294-2F Sand Filter. In addition, it simulates the fate and transport through the vadose zone, the Upper Three Runs (UTR) aquifer, and the Upper Three Runs (UTR) creek. The model is designed as a stochastic model, and as such it can provide both deterministic and stochastic (probabilistic) results. The results show that the median radium activity concentrations exceed the 5 ?Ci/L radium MCL at the edge of the building for all ISD alternatives after 10,000 years, except those with a sufficient amount of inventory removed. A very interesting result was that grouting was shown to basically have minimal effect on the radium activity concentration. During the first 1,000 years grouting may have some small positive benefit relative to radium, however after that it may have a slightly deleterious effect. The Pb-210 results, relative to its 0.06 ?Ci/L PRG, are essentially identical to the radium results, but the Pb-210 results exhibit a lesser degree of exceedance. In summary, some level of inventory removal will be required to ensure that groundwater standards are met.

Taylor, G. A.; Phifer, M. A.

2012-09-14T23:59:59.000Z

Note: This page contains sample records for the topic "transportation greet model" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Reactive transport model for the ambient unsaturated hydrogeochemical system at Yucca mountain, Nevada  

Science Conference Proceedings (OSTI)

To assist a technical review of a potential application for a geologic repository, a reactive transport model is presented for the ambient hydrogeochemical system at Yucca Mountain (YM). The model simulates two-phase, nonisothermal, advective and diffusive ... Keywords: Yucca mountain, geochemistry, groundwater chemistry, groundwater flow and transport, hydrology, reactive transport model, unsaturated zone

Lauren Browning; William M. Murphy; Chandrika Manepally; Randall Fedors

2003-04-01T23:59:59.000Z

142

Benchmarking a Visual-Basic based multi-component one-dimensional reactive transport modeling tool  

Science Conference Proceedings (OSTI)

We present the details of a comprehensive numerical modeling tool, RT1D, which can be used for simulating biochemical and geochemical reactive transport problems. The code can be run within the standard Microsoft EXCEL Visual Basic platform, and it does ... Keywords: Bioremediation, Geochemical transport, Groundwater models, Numerical model, Reactive transport

Jagadish Torlapati; T. Prabhakar Clement

2013-01-01T23:59:59.000Z

143

Transportation Sector Module 1999 Appendix A. Input Data and Parameters, Model Documentation  

Reports and Publications (EIA)

As a component of the National Energy Modeling System integrated forecasting tool, thetransportation model generates mid-term forecasts of transportation sector energy consumption. The transportation model facilitates policy analysis of energy markets, technological development, environmental issues, and regulatory development as they impact transportation sector energy consumption.

John Maples

1999-01-01T23:59:59.000Z

144

Transportation Sector Model of the National Energy Modeling System. Volume 1  

SciTech Connect

This report documents the objectives, analytical approach and development of the National Energy Modeling System (NEMS) Transportation Model (TRAN). The report catalogues and describes the model assumptions, computational methodology, parameter estimation techniques, model source code, and forecast results generated by the model. The NEMS Transportation Model comprises a series of semi-independent models which address different aspects of the transportation sector. The primary purpose of this model is to provide mid-term forecasts of transportation energy demand by fuel type including, but not limited to, motor gasoline, distillate, jet fuel, and alternative fuels (such as CNG) not commonly associated with transportation. The current NEMS forecast horizon extends to the year 2010 and uses 1990 as the base year. Forecasts are generated through the separate consideration of energy consumption within the various modes of transport, including: private and fleet light-duty vehicles; aircraft; marine, rail, and truck freight; and various modes with minor overall impacts, such as mass transit and recreational boating. This approach is useful in assessing the impacts of policy initiatives, legislative mandates which affect individual modes of travel, and technological developments. The model also provides forecasts of selected intermediate values which are generated in order to determine energy consumption. These elements include estimates of passenger travel demand by automobile, air, or mass transit; estimates of the efficiency with which that demand is met; projections of vehicle stocks and the penetration of new technologies; and estimates of the demand for freight transport which are linked to forecasts of industrial output. Following the estimation of energy demand, TRAN produces forecasts of vehicular emissions of the following pollutants by source: oxides of sulfur, oxides of nitrogen, total carbon, carbon dioxide, carbon monoxide, and volatile organic compounds.

NONE

1998-01-01T23:59:59.000Z

145

IMPACTT5A model : enhancements and modifications since December 1994 - with special reference to the effect of tripled-fuel-economy vehicles on fuel-cycle energy and emissions.  

DOE Green Energy (OSTI)

Version 5A of the Integrated Market Penetration and Anticipated Cost of Transportation Technologies (IMPACTT5A) model is a spreadsheet-based set of algorithms that calculates the effects of advanced-technology vehicles on baseline fuel use and emissions. Outputs of this Argonne National Laboratory-developed model include estimates of (1) energy use and emissions attributable to conventional-technology vehicles under a baseline scenario and (2) energy use and emissions attributable to advanced- and conventional-technology vehicles under an alternative market-penetration scenario. Enhancements to IMPACIT made after its initial documentation in December 1994 have enabled it to deal with a wide range of fuel and propulsion system technologies included in Argonne's GREET model in a somewhat modified three-phased approach. Vehicle stocks are still projected in the largely unchanged STOCK module. Vehicle-miles traveled, fuel use, and oil displacement by advanced-technology vehicles are projected in an updated USAGE module. Now, both modules can incorporate vehicle efficiency and fuel share profiles consistent with those of the Partnership for a New Generation of Vehicles. Finally, fuel-cycle emissions of carbon monoxide, volatile organic compounds, nitrogen oxides, toxics, and greenhouse gases are computed in the EMISSIONS module via an interface with the GREET model that was developed specifically to perform such calculations. Because of this interface, results are now more broadly informative than were results from earlier versions of IMPACTT.

Mintz, M. M.; Saricks, C. L.

1999-08-28T23:59:59.000Z

146

Transportation  

Science Conference Proceedings (OSTI)

Transportation systems are an often overlooked critical infrastructure component. These systems comprise a widely diverse elements whose operation impact all aspects of society today. This chapter introduces the key transportation sectors and illustrates ...

Mark Hartong; Rajn Goel; Duminda Wijesekera

2012-01-01T23:59:59.000Z

147

Model documentation report: Transportation sector model of the National Energy Modeling System  

DOE Green Energy (OSTI)

Over the past year, several modifications have been made to the NEMS Transportation Model, incorporating greater levels of detail and analysis in modules previously represented in the aggregate or under a profusion of simplifying assumptions. This document is intended to amend those sections of the Model Documentation Report (MDR) which describe these superseded modules. Significant changes have been implemented in the LDV Fuel Economy Model, the Alternative Fuel Vehicle Model, the LDV Fleet Module, and the Highway Freight Model. The relevant sections of the MDR have been extracted from the original document, amended, and are presented in the following pages. A brief summary of the modifications follows: In the Fuel Economy Model, modifications have been made which permit the user to employ more optimistic assumptions about the commercial viability and impact of selected technological improvements. This model also explicitly calculates the fuel economy of an array of alternative fuel vehicles (AFV`s) which are subsequently used in the estimation of vehicle sales. In the Alternative Fuel Vehicle Model, the results of the Fuel Economy Model have been incorporated, and the program flows have been modified to reflect that fact. In the Light Duty Vehicle Fleet Module, the sales of vehicles to fleets of various size are endogenously calculated in order to provide a more detailed estimate of the impacts of EPACT legislation on the sales of AFV`s to fleets. In the Highway Freight Model, the previous aggregate estimation has been replaced by a detailed Freight Truck Stock Model, where travel patterns, efficiencies, and energy intensities are estimated by industrial grouping. Several appendices are provided at the end of this document, containing data tables and supplementary descriptions of the model development process which are not integral to an understanding of the overall model structure.

NONE

1997-02-01T23:59:59.000Z

148

Argonne Transportation 2005 News  

NLE Websites -- All DOE Office Websites (Extended Search)

5 Transportation News & Highlights 5 Transportation News & Highlights Recycling Automotive Plastics Is Profitable and Good for the Environment November 15, 2005 -- Recycling is not just good for the environment, it is good for business. Argonne researchers have developed a technology to successfully recover plastic from obsolete automobiles that may add plastic to the list of valuable materials recycled from old cars and trucks. (More...) GREETing a Cleaner, More Energy-Efficient Future November 3, 2005 -- Argonne researchers have developed software that is now the government and industry standard for evaluating various vehicle and fuel combinations on a consistent fuel-cycle basis from extracting the energy feedstocks -petroleum and natural gas - through fuel production to final vehicle operation. (More...)

149

Measure of Diffusion Model Error for Thermal Radiation Transport  

E-Print Network (OSTI)

The diffusion approximation to the equation of transfer (Boltzmann transport equation) is usually applied to media where scattering dominates the interactions. Diffusion approximation helps in significant savings in terms of code complexity and computational time. However, this approximation often has significant error. Error due to the inherent nature of a physics model is called model error. Information about the model error associated with the diffusion approximation is clearly desirable. An indirect measure of model error is a quantity that is related in some way to the error but not equal to the error. In general, indirect measures of error are expected to be less costly than direct measures. Perhaps the most well-known indirect measure of the diffusion model error is the variable-Eddington tensor. This tensor provides a great deal of information about the angular dependence of the angular intensity solution, but it is not always simple to interpret. We define a new indirect measure of the diffusion model error called the diffusion model error source (DME source). When this DME source is added to the diffusion equation, the transport solution for the angular-integrated intensity is obtained. In contrast to the variable-Eddington tensor, our DME source is a scalar that is conceptually easy to interpret. In addition to defining the DME source analytically, we show how to generate this source numerically relative to the Sn radiative transfer equations with linear-discontinuous spatial discretization. This numerical source is computationally tested and shown to reproduce the Sn solution for a number of problems. Our radiative transfer model solves a coupled, time dependent, multi-frequency, 1-D slab equation and material heat transfer equation. We then use diffusion approximation to solve the same problem. The difference due to this approximation can be modelled by a diffusion source. The diffusion source is defined as an amount of inhomogeneous source that, when added to a diffusion calculation, gives a solution for the angle-integrated intensity that is equal to the transport solution.

Kumar, Akansha

2013-05-01T23:59:59.000Z

150

MODELING TRITIUM TRANSPORT, DEPOSITION AND RE-EMISSION  

Science Conference Proceedings (OSTI)

The atmospheric release of tritium oxide (HTO) potentially impacts human health, typically through inhalation or absorption. Due to HTO's similarity to water, vegetation will absorb HTO by solution in the leaf water and then re-emit it, creating a number of secondary sources of HTO. Currently, models used for emergency response at Savannah River Site incorporate the transport and deposition of HTO but do not provide estimates for its potential re-emission from vegetation or soil surface though re-emission could result in prolonged exposure and greater than predicted dose for an individual downwind. A simple model of HTO transport, deposition and re-emission has been developed to examine the potential increase in exposure and dose. The model simulates an initial release of HTO that moves with a mean wind and expands through diffusion as a Gaussian puff. Deposition is modeled using previous estimates of deposition velocity for HTO and re-emission is modeled using a time constant that describes how quickly HTO is transferred between the surface and atmosphere. Additional puffs are created to simulate re-emission of HTO as well as horizontal diffusion across model grid cells. An evaluation of field data indicates that the use of a re-emission module tends to improve model predictions through improved prediction of peak concentration magnitude and location. When considering dose, nearly all of the released material is included in the dose calculation when re-emission is included. Although exposure to HTO through re-emission occurs over a few hours, the incremental increase in dose is relatively small because the atmospheric concentration of re-emitted HTO is much lower than the initial release.

Viner, B.

2012-04-03T23:59:59.000Z

151

Upscaling reactive transport in porous media : laboratory visualization and stochastic models  

E-Print Network (OSTI)

Solute transport models are essential tools for understanding and forecasting chemical concentrations in groundwater. Advection-dispersion based models can adequately predict spatial averages of conservative solute ...

Oates, Peter M. (Peter Michael), 1977-

2007-01-01T23:59:59.000Z

152

Aerosols and clouds in chemical transport models and climate models.  

Science Conference Proceedings (OSTI)

Clouds exert major influences on both shortwave and longwave radiation as well as on the hydrological cycle. Accurate representation of clouds in climate models is a major unsolved problem because of high sensitivity of radiation and hydrology to cloud properties and processes, incomplete understanding of these processes, and the wide range of length scales over which these processes occur. Small changes in the amount, altitude, physical thickness, and/or microphysical properties of clouds due to human influences can exert changes in Earth's radiation budget that are comparable to the radiative forcing by anthropogenic greenhouse gases, thus either partly offsetting or enhancing the warming due to these gases. Because clouds form on aerosol particles, changes in the amount and/or composition of aerosols affect clouds in a variety of ways. The forcing of the radiation balance due to aerosol-cloud interactions (indirect aerosol effect) has large uncertainties because a variety of important processes are not well understood precluding their accurate representation in models.

Lohmann,U.; Schwartz, S. E.

2008-03-02T23:59:59.000Z

153

Mathematical models of thermal and chemical transport in geologic media  

DOE Green Energy (OSTI)

Semi-analytical and numerical methods are used to investigate thermal and chemical transport processes in geologic media. The work is divided into two parts: (1) development of semi-analytical models for the analysis of uncoupled isothermal and nonisothermal fluid flow in naturally fractured media, and (2) development of a high resolution numerical code to address coupled nonisothermal chemical transport in geologic media. A semi-analytical model is developed for well test data analysis in naturally fractured reservoirs. A simple approximate analytical solution for pressure buildup and drawdown tests is developed. Methods based on the approximate solution are developed for the evaluation of important reservoir properties. Type curves for nonisothermal fluid flow in naturally fractured media are developed to design injection systems for maximum energy in hydrothermal systems. An accurate finite difference method for the solution of a convection-diffusion type equation is developed. The method is incorporated in a two-dimensional code to investigate free convection in a porous slab and kinetic silica-water reactions in geothermal systems. A multicomponent model considering the variations of pressure, temperature and silica concentration is developed to interpret the evolution of geothermal systems during exploitation.

Lai, C.-H.

1985-12-01T23:59:59.000Z

154

A concurrent, multigroup, discrete ordinates model of neutron transport  

SciTech Connect

The authors present an algorithm for the concurrent solution of the linear system arising from a multigroup, discrete ordinates model of neutron transport. The target architectures consist of distributed memory computers ranging from workstation clusters to massively parallel computers. Based on an analysis of the memory requirement and floating point complexity of matrix-vector multiplication in the iterative solution of the linear system, the authors propose a data layout and communication strategy designed to achieve scalability with respect to all phase space variables. Numerical results are presented to demonstrate the performance of the algorithm on the nCUBE/2.

Dorr, M.R.; Still, C.H.

1993-10-22T23:59:59.000Z

155

Mobile model and transportation planning: A brief overview  

Science Conference Proceedings (OSTI)

MOBILE is a computer model developed by the U.S. Environmental Protection Agency (EPA) for estimating emissions of air pollutants by motor vehicles. Using information on the types and ages of vehicles and on local driving conditions, MOBILE estimates emissions of various pollutants during each mile that different types of vehicles are driven. These emissions rates are combined with transportation planners` estimated of the number of miles vehicles are driven within the region to estimate area-wide total emissions of each pollutant by highway vehicles, usually during a day or year.

NONE

1996-04-01T23:59:59.000Z

156

Transport Diagnostics of GCMs and Implications for 2D Chemistry-Transport Model of Troposphere and Stratosphere  

Science Conference Proceedings (OSTI)

The middle atmosphere version of NCAR Community Climate Model (MACCM2) and the GEOS-STRATAN data assimilation system (DAS) of NASA/GSFC have been used to generate a zonally averaged set of transport parameters (meridional circulation and resolved ...

Valery A. Yudin; Sergey P. Smyshlyaev; Marvin A. Geller; Victor L. Dvortsov

2000-03-01T23:59:59.000Z

157

Zinc Uptake and Radial Transport in Roots of Arabidopsis thaliana: A Modelling Approach to Understand Accumulation  

E-Print Network (OSTI)

Zinc uptake in roots is believed to be mediated by ZIP (ZRT-, IRT- like Proteins) transporters. Once inside the symplast, zinc is transported to the pericycle, where it exits by means of HMA (Heavy Metal ATPase) transporters. The combination of symplastic transport and spatial separation of influx and efflux produces a pattern in which zinc accumulates in the pericycle. Here, mathematical modelling was employed to study the importance of ZIP regulation, HMA level and symplastic transport in creation of the radial pattern of zinc in primary roots of Arabidopsis thaliana. A comprehensive one-dimensional dynamical model of radial zinc transport in roots was developed and used to conduct simulations. The model accounts for the structure of the root consisting of symplast and apoplast and includes effects of water flow, diffusion, and cross-membrane transport via transporters. It also incorporates the radial geometry and varying porosity of root tissues, as well as regulation of ZIP transporters. Steady state patt...

Claus, Juliane; Chavarra-Krauser, Andrs

2012-01-01T23:59:59.000Z

158

Reactive transport in aquatic ecosystems: Rapid model prototyping in the open source software R  

Science Conference Proceedings (OSTI)

The concentrations of many natural compounds are altered by chemical and biological transformations, and physical processes such as adsorption and transport. Their fate can be predicted using reactive transport models that describe reaction and advective ... Keywords: Model, Open source, R, Reactive transport, Software

Karline Soetaert; Filip Meysman

2012-06-01T23:59:59.000Z

159

Transportation  

NLE Websites -- All DOE Office Websites (Extended Search)

Meier AKMeier@lbl.gov (510) 486-4740 Links Transportation and Air Quality Batteries and Fuel Cells Buildings Energy Efficiency Electricity Grid Energy Analysis Energy...

160

Modeling of thermal transport properties of multiphase porous materials  

Science Conference Proceedings (OSTI)

This work presents a numerical framework for modeling thermal transport properties of multiphase porous materials with complex internal microstructures. The framework includes two steps. First, a random generation-growth algorithm is highlighted for reproducing multiphase microstructures, statistically equivalent to the actual systems, based on the geometrical and morphological information obtained from measurements and experimental estimations. Then a high-efficiency lattice Boltzmann solver for the corresponding governing equations is described, which, while assuring energy conservation and appropriate continuities at the interfaces in a complex system, has demonstrated its numerical power in yielding accurate solutions. Various applications are provided to validate the feasibility, effectiveness and robustness of this new framework by comparing the predictions with existing experimental data for different transport processes, accounting for the effects due to internal morphology, microstructural anisotropy, and multi phase interactions. The examples given also suggest potential applicability of this methodology to other problems as long as they are governed by similar partial differential equation(s). Thus, for given composition and structure, this numerical methodology is in essence a model built on sound physics principles with prior validity, without resorting to any ad hoc empirical treatment. Therefore, it is useful for design and optimization of new materials, beyond just predicting and analyzing the existing ones.

Wang, Moran [Los Alamos National Laboratory; Kang, Qinjun [Los Alamos National Laboratory; Robinson, Bruce [Los Alamos National Laboratory; Ning, Pan [UC DAVIS

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "transportation greet model" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Azimuthal Anisotropies as Stringent Test for Nuclear Transport Models  

E-Print Network (OSTI)

Azimuthal distributions of charged particles and intermediate mass fragments emitted in Au+Au collisions at 600AMeV have been measured using the FOPI facility at GSI-Darmstadt. Data show a strong increase of the in-plane azimuthal anisotropy ratio with the charge of the detected fragment. Intermediate mass fragments are found to exhibit a strong momentum-space alignment with respect of the reaction plane. The experimental results are presented as a function of the polar center-of-mass angle and over a broad range of impact parameters. They are compared to the predictions of the Isospin Quantum Molecular Dynamics model using three different parametrisations of the equation of state. We show that such highly accurate data provide stringent test for microscopic transport models and can potentially constrain separately the stiffness of the nuclear equation of state and the momentum dependence of the nuclear interaction.

P. Crochet; F. Rami; R. Dona; the FOPI Collaboration

1997-09-15T23:59:59.000Z

162

Stochastic Models for the Kinematics of Moisture Transport and Condensation in Homogeneous Turbulent Flows  

Science Conference Proceedings (OSTI)

The transport of a condensing passive scalar is studied as a prototype model for the kinematics of moisture transport on isentropic surfaces. Condensation occurs whenever the scalar concentration exceeds a specified local saturation value. Since ...

Paul A. OGorman; Tapio Schneider

2006-11-01T23:59:59.000Z

163

Kinetic modelling of molecular hydrogen transport in microporous carbon materials.  

DOE Green Energy (OSTI)

The proposal of kinetic molecular sieving of hydrogen isotopes is explored by employing statistical rate theory methods to describe the kinetics of molecular hydrogen transport in model microporous carbon structures. A Lennard-Jones atom-atom interaction potential is utilized for the description of the interactions between H{sub 2}/D{sub 2} and the carbon framework, while the requisite partition functions describing the thermal flux of molecules through the transition state are calculated quantum mechanically in view of the low temperatures involved in the proposed kinetic molecular sieving application. Predicted kinetic isotope effects for initial passage from the gas phase into the first pore mouth are consistent with expectations from previous modeling studies, namely, that at sufficiently low temperatures and for sufficiently narrow pore mouths D{sub 2} transport is dramatically favored over H{sub 2}. However, in contrast to expectations from previous modeling, the absence of any potential barrier along the minimum energy pathway from the gas phase into the first pore mouth yields a negative temperature dependence in the predicted absolute rate coefficients - implying a negative activation energy. In pursuit of the effective activation barrier, we find that the minimum potential in the cavity is significantly higher than in the pore mouth for nanotube-shaped models, throwing into question the common assumption that passage through the pore mouths should be the rate-determining step. Our results suggest a new mechanism that, depending on the size and shape of the cavity, the thermal activation barrier may lie in the cavity rather than at the pore mouth. As a consequence, design strategies for achieving quantum-mediated kinetic molecular sieving of H{sub 2}/D{sub 2} in a microporous membrane will need, at the very least, to take careful account of cavity shape and size in addition to pore-mouth size in order to ensure that the selective step, namely passage through the pore mouth, is also the rate determining step.

Hankel, M.; Zhang, H.; Nguyen, T. X.; Bhatia, S. K.; Gray, S. K.; Smith, S. C. (Center for Nanoscale Materials); (The Univ. of Queensland)

2011-01-01T23:59:59.000Z

164

Coupled MHD-Monte Carlo transport model for dense plasmas  

SciTech Connect

A two-dimensional, two fluid model of the MHD equations has been coupled to a Monte Carlo transport model of high energy, non-Maxwellian ions. The MHD part of the model assumes complete ionization and includes a perfect gas law for a scalar pressure, a tensor artificial viscosity, electron and ion thermal conduction, electron-ion coupling, and a radiation loss term. A simple Ohm's Law is used with a B/sub theta/ magnetic field. The MHD equations were solved in Lagrangian coordinates. The conservation equations were differenced explicitly and the diffusion-type equations implicitly using the splitting technique. The Monte Carlo model solves the equation of motion for high energy ions, moving through and suffering small and large angle collisions with the fluid Maxwellian plasma. The source of high energy ions is the thermonuclear reactions of the hydrogen isotopes, or it may be an externally injected beam of neutralized ions. In addition to using the usual Maxwell averaged thermonuclear cross sections for calculating the number of reactions taking place within the Maxwellian plasma, the high energy ions may suffer collisions resulting in a reaction. In the Monte Carlo model all neutrons are assumed to escape, and all energetic ions of Z less than or equal to 2 are followed. (auth)

Chandler, W.P.

1975-06-01T23:59:59.000Z

165

Modeling of the solids transportation within an industrial rotary dryer: A simple model  

SciTech Connect

To better understand the underlying phenomena taking place in an industrial rotary dryer and to determine the optimum operating conditions, a simulator in which the solids transportation, the gas flow, and the heat and mass transfer are modeled is currently being developed. This paper describes the use of interactive perfect mixers in series to model the solids transportation within an industrial rotary dryer, on the basis of an experimental residence time distribution curve (RTD). Two simple models are proposed: a series of perfect well-mixed interacting tanks and a modified Cholette-Cloutier model. The first model is not able to account for the nonideal behavior of the solids transportation in the rotary dryer. To account for the characteristic extended tail of the RTD curves observed in industrial dryers, in a second model, the solid phase is divided between an active and a dead zone. This model, with 36 cells and 25% of the volume occupied by the dead zones, modeled very well the industrial RTD curve. In addition, the model produces bed depth and axial velocity profiles that are consistent with those reported in the literature.

Duchesne, C.; Thibault, J.; Bazin, C. [Laval Univ., Sainte-Foy, Quebec (Canada)] [Laval Univ., Sainte-Foy, Quebec (Canada)

1996-07-01T23:59:59.000Z

166

TOUGH2. Unsaturated Groundwater and Heat Transport Model  

DOE Green Energy (OSTI)

TOUGH2 is a new and improved version of TOUGH. TOUGH2 offers added capabilities and user features, including the flexibility to handle different fluid mixtures (water, water with tracer; water, CO2; water, air; water, air, with vapor pressure lowering and water, hydrogen), facilities for processing of geometric data (computational grids), and an internal version control system to ensure referenceability of code applications. TOUGH2 is a multi-dimensional numerical model for simulating the coupled transport of water, vapor, air, and heat in porous and fractured media. The program provides options for specifying injection or withdrawal of heat and fluids. Although primarily designed for studies of high-level nuclear waste isolation in partially saturated geological media, it should also be useful for a wider range of problems in heat and moisture transfer, and in the drying of porous materials. For example, geothermal reservoir simulation problems can be handled simply by setting the air mass function equal to zero on input. The TOUGH2 simulator was developed for problems involving strongly heat-driven flow. To describe these phenomena a multi-phase approach to fluid and heat flow is used, which fully accounts for the movement of gaseous and liquid phases, their transport of latent and sensible heat, and phase transitions between liquid and vapor. TOUGH2 takes account of fluid flow in both liquid and gaseous phases occurring under pressure, viscous, and gravity forces according to Darcy`s law. Interference between the phases is represented by means of relative permeability functions. The code handles binary, but not Knudsen, diffusion in the gas phase and capillary and phase adsorption effects for the liquid phase. Heat transport occurs by means of conduction with thermal conductivity dependent on water saturation, convection, and binary diffusion, which includes both sensible and latent heat.

Pruess, K. [Lawrence Berkeley National Lab., CA (United States)

1991-05-01T23:59:59.000Z

167

Compendium of Material Composition Data for Radiation Transport Modeling  

Science Conference Proceedings (OSTI)

Introduction Meaningful simulations of radiation transport applications require realistic definitions of material composition and densities. When seeking that information for applications in fields such as homeland security, radiation shielding and protection, and criticality safety, researchers usually encounter a variety of materials for which elemental compositions are not readily available or densities are not defined. Publication of the Compendium of Material Composition Data for Radiation Transport Modeling, Revision 0, in 2006 was the first step toward mitigating this problem. Revision 0 of this document listed 121 materials, selected mostly from the combined personal libraries of staff at the Pacific Northwest National Laboratory (PNNL), and thus had a scope that was recognized at the time to be limited. Nevertheless, its creation did provide a well-referenced source of some unique or hard-to-define material data in a format that could be used directly in radiation transport calculations being performed at PNNL. Moreover, having a single common set of material definitions also helped to standardize at least one aspect of the various modeling efforts across the laboratory by providing separate researchers the ability to compare different model results using a common basis of materials. The authors of the 2006 compendium understood that, depending on its use and feedback, the compendium would need to be revised to correct errors or inconsistencies in the data for the original 121 materials, as well as to increase (per users suggestions) the number of materials listed. This 2010 revision of the compendium has accomplished both of those objectives. The most obvious change is the increased number of materials from 121 to 372. The not-so-obvious change is the mechanism used to produce the data listed here. The data listed in the 2006 document were compiled, evaluated, entered, and error-checked by a group of individuals essentially by hand, providing no library file or mechanism for revising the data in a consistent and traceable manner. The authors of this revision have addressed that problem by first compiling all of the information (i.e., numbers and references) for all the materials into a single database, maintained at PNNL, that was then used as the basis for this document.

McConn, Ronald J.; Gesh, Christopher J.; Pagh, Richard T.; Rucker, Robert A.; Williams III, Robert

2011-03-04T23:59:59.000Z

168

Greetings from Kyoto-U AUTUMN 2008 C O N T E N T S  

E-Print Network (OSTI)

of Methodologies Used by Less-Than-Truckload (LTL) Motor Carriers to Determine Fuel Surcharges 5. Report Date of this and other research reports. 16. Abstract Fuel surcharge policies are utilized by transportation companies to transfer the expense associated with fuel prices to their customers. As fuel surcharges have become

Takada, Shoji

169

Transportation planning for mega events : a model of urban change  

E-Print Network (OSTI)

My study is about opportunities for revolutionary developments in urban transport. Often, we think of transport and urban development as an evolutionary process, yet there exist a few opportunities for cities to revolutionize ...

Kassens, Eva

2009-01-01T23:59:59.000Z

170

Model Development and Analysis of the Fate and Transport of Water in a Salt  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Model Development and Analysis of the Fate and Transport of Water Model Development and Analysis of the Fate and Transport of Water in a Salt Based Repository Model Development and Analysis of the Fate and Transport of Water in a Salt Based Repository The study summarizes the initial work on numerical modeling, simulations, and experimental results related to nuclear waste storage in a salt repository. The study reflects the project's preliminary effort at simulating the fluid flow and heat transport processes, before treating the fully coupled thermal-mechanical-hydrologic-chemical (TMHC) coupled processes in the future. Model Development and Analysis of the Fate and Transport of Water in a Salt Based Repository More Documents & Publications Coupled Model for Heat and Water Transport in a High Level Waste Repository

171

Modeling the Prospects for Hydrogen Powered Transportation Through 2100  

E-Print Network (OSTI)

Hydrogen fueled transportation has been proposed as a low carbon alternative to the current gasoline-powered

Sandoval, Reynaldo.

172

Three-dimensional model for multi-component reactive transport with variable density groundwater flow  

Science Conference Proceedings (OSTI)

PHWAT is a new model that couples a geochemical reaction model (PHREEQC-2) with a density-dependent groundwater flow and solute transport model (SEAWAT) using the split-operator approach. PHWAT was developed to simulate multi-component reactive transport ... Keywords: Cation exchange, Coastal groundwater flow and chemical transport/reaction, Density-dependent flow, MODFLOW, MT3DMS, PHREEQC-2, PHWAT, SEAWAT, Seawater intrusion, Snow-plough effect

X. Mao; H. Prommer; D. A. Barry; C. D. Langevin; B. Panteleit; L. Li

2006-05-01T23:59:59.000Z

173

Flow Allocation Model and Algorithm Based on Multi-target Coal Transportation Network  

Science Conference Proceedings (OSTI)

Coal transportation network consists of multiple logistics nodes and transportation paths. As the node capacity and cost factors is limited, its flow distribution is a multi-target and multi-constraint problem. Through the use of multi-target planning ... Keywords: flow allocation, model, algorithm, multi-target, coal transportation network

Tingting Zhu; Tianjun Hu; Xifu Wang; Yalong Zhao

2012-04-01T23:59:59.000Z

174

Lessons learned from reactive transport modeling of a low-activity waste glass disposal system  

Science Conference Proceedings (OSTI)

A set of reactive chemical transport calculations were conducted with the Subsurface Transport Over Reactive Multiphases (STORM) code to evaluate the long-term performance of a representative low-activity waste glass in a shallow subsurface disposal ... Keywords: chemical transport, low-level waste, numerical model, unsaturated flow, vadose zone

Diana H. Bacon; B. Peter McGrail

2003-04-01T23:59:59.000Z

175

Efficient Schemes for Reducing Numerical Dispersion in Modeling Multiphase Transport through Porous and Fractured Media  

E-Print Network (OSTI)

within a fluid in a multiphase- porous-medium system isand radiation in a multiphase, multicomponent, porous mediumModeling Multiphase Transport through Porous and Fractured

Wu, Yu-Shu; Forsyth, Peter A.

2006-01-01T23:59:59.000Z

176

Modeling Gas Transport in the Shallow Subsurface During the ZERT CO2 Release Test  

E-Print Network (OSTI)

Research Forum (PERF) Dense Gas Dispersion Modeling Project,Atmospheric dispersion of dense gases, Ann. Rev. Fluidgas (LNG) terminals and transport, and emphasize atmospheric dispersion

Oldenburg, Curtis M.

2009-01-01T23:59:59.000Z

177

Heat Transport in Groundwater Systems--Laboratory Model  

E-Print Network (OSTI)

Solar energy is a possible alternate energy source for space heating. A method of economic long term solar energy storage is needed. Researchers have proposed storing solar energy by heating water using solar collectors and injecting the hot water into groundwater aquifers for long term energy storage. Of paramount importance to the success of such a system is the quality and the behavior of the aquifer used for hot water storage. In general, the problem is to obtain an accurate prediction of the response of an aquifer system and its basic components to the operation of a system of injection and pumping wells which are transporting water at a notably different temperature than the natural groundwater. The injection of hot water into a groundwater storage system will have a pronounced effect on the specific storage and mass flow within the aquifer. These effects will result from differences in viscosity, density, specific heat, and thermal conductivity between the injected water and the natural groundwater. A complex system of energy and mass transport will result, making analytical solutions unattainable or very complex. The objective of this study was to develop a numerical simulation which would predict the pressure and temperature of water in a groundwater system at any time in response to the pumping and injecting of hot and cold water. A numerical model was developed in which the groundwater flow equation and the energy transport equation are solved simultaneously using a finite difference approximation for the time derivative and three-dimensional Galerkin-finite element approximations for the space derivatives. The use of a strict Galerkin approach led to unacceptable solution oscillations in sharp temperature front problems (i.e., problems where the temperature changes quickly over a small distance or time). Several techniques were tried in an attempt to correct the problem. Reduction of element and time step size proved ineffective in eliminating the sharp temperature front oscillation problem. An upstream weighting scheme corrected the oscillation problem, but resulted in an unacceptable smear of the sharp temperature front. A mass lumping scheme resulted in the best solution to sharp temperature front problems. The mass lumping scheme yielded solutions without the oscillation problem and with less smear than the upstream weighting scheme.

Reed, D. B.; Reddell, D. L.

1980-08-01T23:59:59.000Z

178

FEMA: a Finite Element Model of Material Transport through Aquifers  

Science Conference Proceedings (OSTI)

This report documents the construction, verification, and demonstration of a Finite Element Model of Material Transport through Aquifers (FEMA). The particular features of FEMA are its versatility and flexibility to deal with as many real-world problems as possible. Mechanisms included in FEMA are: carrier fluid advection, hydrodynamic dispersion and molecular diffusion, radioactive decay, sorption, source/sinks, and degradation due to biological, chemical as well as physical processes. Three optional sorption models are embodied in FEMA. These are linear isotherm and Freundlich and Langmuir nonlinear isotherms. Point as well as distributed source/sinks are included to represent artificial injection/withdrawals and natural infiltration of precipitation. All source/sinks can be transient or steady state. Prescribed concentration on the Dirichlet boundary, given gradient on the Neumann boundary segment, and flux at each Cauchy boundary segment can vary independently of each other. The aquifer may consist of as many formations as desired. Either completely confined or completely unconfined or partially confined and partially unconfined aquifers can be dealt with effectively. FEMA also includes transient leakage to or from the aquifer of interest through confining beds from or to aquifers lying below and/or above.

Yeh, G.T.; Huff, D.D.

1985-01-01T23:59:59.000Z

179

Transportation Sector Model of the National Energy Modeling System. Volume 2 -- Appendices: Part 2  

Science Conference Proceedings (OSTI)

The attachments contained within this appendix provide additional details about the model development and estimation process which do not easily lend themselves to incorporation in the main body of the model documentation report. The information provided in these attachments is not integral to the understanding of the model`s operation, but provides the reader with opportunity to gain a deeper understanding of some of the model`s underlying assumptions. There will be a slight degree of replication of materials found elsewhere in the documentation, made unavoidable by the dictates of internal consistency. Each attachment is associated with a specific component of the transportation model; the presentation follows the same sequence of modules employed in Volume 1. The following attachments are contained in Appendix F: Fuel Economy Model (FEM)--provides a discussion of the FEM vehicle demand and performance by size class models; Alternative Fuel Vehicle (AFV) Model--describes data input sources and extrapolation methodologies; Light-Duty Vehicle (LDV) Stock Model--discusses the fuel economy gap estimation methodology; Light Duty Vehicle Fleet Model--presents the data development for business, utility, and government fleet vehicles; Light Commercial Truck Model--describes the stratification methodology and data sources employed in estimating the stock and performance of LCT`s; Air Travel Demand Model--presents the derivation of the demographic index, used to modify estimates of personal travel demand; and Airborne Emissions Model--describes the derivation of emissions factors used to associate transportation measures to levels of airborne emissions of several pollutants.

NONE

1998-01-01T23:59:59.000Z

180

Optimizing U.S. Mitigation Strategies for the Light-Duty Transportation Sector: What We Learn from a Bottom-Up Model  

E-Print Network (OSTI)

types of ethanol: corn ethanol and cellulosic ethanol. ManyInput assumptions for corn ethanol and cellulosic ethanolMost of the values for corn ethanol are extracted from GREET

Yeh, Sonia; Farrell, Alexander E.; Plevin, Richard J; Sanstad, Alan; Weyant, John

2008-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "transportation greet model" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

The National Energy Modeling System: An Overview 1998 - Transportation  

Gasoline and Diesel Fuel Update (EIA)

TRANSPORTATION DEMAND MODULE TRANSPORTATION DEMAND MODULE blueball.gif (205 bytes) Fuel Economy Submodule blueball.gif (205 bytes) Regional Sales Submodule blueball.gif (205 bytes) Alternative-Fuel Vehicle Submodule blueball.gif (205 bytes) Light-Duty Vehicle Stock Submodule blueball.gif (205 bytes) Vehicle-Miles Traveled (VMT) Submodule blueball.gif (205 bytes) Light-Duty Vehicle Commercial Fleet Submodule blueball.gif (205 bytes) Commercial Light Truck Submodule blueball.gif (205 bytes) Air Travel Demand Submodule blueball.gif (205 bytes) Aircraft Fleet Efficiency Submodule blueball.gif (205 bytes) Freight Transport Submodule blueball.gif (205 bytes) Miscellaneous Energy Use Submodule The transportation demand module (TRAN) forecasts the consumption of transportation sector fuels by transportation mode, including the use of

182

Model Development and Analysis of the Fate and Transport of Water in a Salt  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Development and Analysis of the Fate and Transport of Water Development and Analysis of the Fate and Transport of Water in a Salt Based Repository Model Development and Analysis of the Fate and Transport of Water in a Salt Based Repository The study summarizes the initial work on numerical modeling, simulations, and experimental results related to nuclear waste storage in a salt repository. The study reflects the project's preliminary effort at simulating the fluid flow and heat transport processes, before treating the fully coupled thermal-mechanical-hydrologic-chemical (TMHC) coupled processes in the future. Model Development and Analysis of the Fate and Transport of Water in a Salt Based Repository More Documents & Publications Coupled Model for Heat and Water Transport in a High Level Waste Repository in Salt

183

City-Scale Transport Modeling: An Approach for Nairobi, Kenya  

E-Print Network (OSTI)

Public Transport Patterns in Kenya: A Case S tudy of NairobiCity. Special Report No. 7. Nairobi, Kenya:Kenya Institute for Public Policy Research and Analysis.

Daganzo, C. F.; Li, Yuwei; Gonzales, Eric J.; Geroliminis, Nikolas

2007-01-01T23:59:59.000Z

184

Toward an understanding of vertical momentum transports in cloud system resolving model simulations of multiscale tropical convection  

Science Conference Proceedings (OSTI)

This study examines the characteristics of convective momentum transport (CMT) and gravity wave momentum transport (GWMT) in two-dimensional cloud-system resolving model simulations, including the relationships between the two transports. A linear ...

Tiffany A. Shaw; Todd P. Lane

185

Ensemble modeling of transport and dispersion simulations guided by machine learning hypotheses generation  

Science Conference Proceedings (OSTI)

In this article an approach is presented where machine learning classifiers are used to drive an ensemble modeling method of multiple atmospheric transport and dispersion simulations. The goal is to achieve a higher spread of the results with a lower ... Keywords: Ensemble modeling, Machine learning, Transport and dispersion simulations

Andreas D. Lattner; Guido Cervone

2012-11-01T23:59:59.000Z

186

Pacific Ocean Heat Transport at 24N in a High-Resolution Global Model  

Science Conference Proceedings (OSTI)

Meridional heat transport in the North Pacific Ocean in a seasonally forced high-resolution global ocean general circulation model is compared to observations. At 24N, annual mean heat transport in the model of 0.371011W is half the most recent ...

John L. Wilkin; James V. Mansbridge; J. Stuart Godfrey

1995-10-01T23:59:59.000Z

187

Transportation Network Routing Models RNL has a staff with extensive  

E-Print Network (OSTI)

Analysis Geo-Spatial Information Tools Defense Transportation Energy Policy Analysis Environmental Policy is a representation of the North American railroad system that contains every active railroad route in the US, Canada are the effects of changes in transportation costs, demands, or policies? ORNL's Comparative Advantage

188

Distributed decision evaluation model in public transportation systems  

Science Conference Proceedings (OSTI)

Due to several external and internal disturbances affecting public transportation systems, some regulation measures have to be undertaken. In the regulation process, the regulator has to evaluate a number of possible decisions in order to determine best ... Keywords: Multi-agent systems, Multicriteria optimization, Pareto optimality, Plurality voting, Public transportation systems, Traffic regulation, a-efficiency

Imen Boudali; Ins Ben Jaafar; Khaled Ghedira

2008-04-01T23:59:59.000Z

189

Atmospheric Transports, the Thermohaline Circulation, and Flux Adjustments in a Simple Coupled Model  

Science Conference Proceedings (OSTI)

A theoretical analysis of the interactions between atmospheric meridional transports and the thermohaline circulation is presented, using a four-box ocean-atmosphere model in one hemisphere. The model is a simplified version of that developed by ...

Jochem Marotzke; Peter H. Stone

1995-06-01T23:59:59.000Z

190

Design and Validation of an Offline Oceanic Tracer Transport Model for a Carbon Cycle Study  

Science Conference Proceedings (OSTI)

An offline passive tracer transport model with self-operating diagnostic-mode vertical mixing and horizontal diffusion parameterizations is used with assimilated ocean currents to find the chlorofluorocarbon (CFC-11) cycle in oceans. This model ...

Vinu Valsala; Shamil Maksyutov; Ikeda Motoyoshi

2008-06-01T23:59:59.000Z

191

The Role of the Nonlocal Transport in Modeling the Shear-Driven Atmospheric Boundary Layer  

Science Conference Proceedings (OSTI)

In this work the role played by the transport equations including nonlocal terms in simulating the atmospheric turbulence is investigated. Two different models are compared: the first one is a standard E? model solving two dynamical equations ...

E. Ferrero; M. Racca

2004-06-01T23:59:59.000Z

192

Modeling Pollutant Transport during High-Ozone Episodes in the Southern Appalachian Mountains  

Science Conference Proceedings (OSTI)

Airflow patterns and pollution transport in the southern Appalachian Mountains region of the southeastern United States are examined using mesoscale meteorological models and a Lagrangian particle dispersion model (LPDM). The two primary goals of ...

Stephen F. Mueller; Aaron Song; William B. Noms; Shekar Gupta; Richard T. McNider

1996-11-01T23:59:59.000Z

193

Implied Ocean Heat Transports in the Standard and Superparameterized Community Atmospheric Models  

Science Conference Proceedings (OSTI)

Implied ocean heat transport (To) based on net surface energy budgets is computed for two versions of the Community Atmospheric Model (CAM, version 3.0) general circulation model (GCM). The first version is the standard CAM with parameterized ...

Charlotte A. DeMott; David A. Randall; Marat Khairoutdinov

2010-04-01T23:59:59.000Z

194

A Diagnostic Analysis of a Long-Term Regional Air Pollutant Transport Model  

Science Conference Proceedings (OSTI)

Predicted concentrations from the Regional Air Pollutant Transport (RAPT) model are compared with the corresponding observed values of sulfate, and the results used to define strengths and weaknesses in the model formulation.

Daniel J. McNaughton; Carl M. Berkowitz; Robert C. Williams

1981-07-01T23:59:59.000Z

195

A Two-Cylinder Model of Cumulus Cells and Its Application in Computing Cumulus Transports  

Science Conference Proceedings (OSTI)

A two-cylinder model suitable for computing vertical transports in cumulus cells is formulated. The model includes explicit computation of perturbation pressure and allows the study of the evolution of raindrop size spectra. Sensitivity tests ...

Man Kong Yau

1980-11-01T23:59:59.000Z

196

Modeling of Transport in Lithium Ion Battery Electrodes  

E-Print Network (OSTI)

Lithium ion battery systems are promising solutions to current energy storage needs due to their high operating voltage and capacity. Numerous efforts have been conducted to model these systems in order to aid the design process and avoid expensive and time consuming prototypical experiments. Of the numerous processes occurring in these systems, solid state transport in particular has drawn a large amount of attention from the research community, as it tends to be one of the rate limiting steps in lithium ion battery performance. Recent studies have additionally indicated that purposeful design of battery electrodes using 3D microstructures offers new freedoms in design, better use of available cell area, and increased battery performance. The following study is meant to serve as a first principles investigation into the behaviors of 3D electrode architectures by monitoring concentration and cycle behaviors under realistic operating conditions. This was accomplished using computational tools to model the solid state diffusion behavior in several generated electrode morphologies. Developed computational codes were used to generate targeted structures under prescribed conditions of particle shape, size, and overall morphology. The diffusion processes in these morphologies were simulated under conditions prescribed from literature. Primary results indicate that parameters usually employed to describe electrode geometry, such as volume to surface area ratio, cannot be solely relied upon to predict or characterize performance. Additionally, the interaction between particle shapes implies some design aspects that may be exploited to improve morphology behavior. Of major importance is the degree of particle isolation and overlap in 3D architectures, as these govern gradient development and lithium depletion within the electrode structures. The results of this study indicate that there are optimum levels of these parameters, and so purposeful design must make use of these behaviors.

Martin, Michael

2012-05-01T23:59:59.000Z

197

Location Analysis Model for Belgian Intermodal Terminals: Importance of the value of time in the intermodal transport chain  

Science Conference Proceedings (OSTI)

Intermodal transport, the combination and integration of several transport modes, with the use of loading units, is in most cases more environmentally friendly than unimodal road transport for the carriage of goods. The LAMBIT-model (Location Analysis ... Keywords: Empty returns, GIS network model, Intermodal transport, Value of time

Ethem Pekin; Cathy Macharis; Dries Meers; Piet Rietveld

2013-02-01T23:59:59.000Z

198

Transportation  

NLE Websites -- All DOE Office Websites (Extended Search)

Due to limited parking, all visitors are strongly encouraged to: Due to limited parking, all visitors are strongly encouraged to: 1) car-pool, 2) take the Lab's special conference shuttle service, or 3) take the regular off-site shuttle. If you choose to use the regular off-site shuttle bus, you will need an authorized bus pass, which can be obtained by contacting Eric Essman in advance. Transportation & Visitor Information Location and Directions to the Lab: Lawrence Berkeley National Laboratory is located in Berkeley, on the hillside directly above the campus of University of California at Berkeley. The address is One Cyclotron Road, Berkeley, California 94720. For comprehensive directions to the lab, please refer to: http://www.lbl.gov/Workplace/Transportation.html Maps and Parking Information: On Thursday and Friday, a limited number (15) of barricaded reserved parking spaces will be available for NON-LBNL Staff SNAP Collaboration Meeting participants in parking lot K1, in front of building 54 (cafeteria). On Saturday, plenty of parking spaces will be available everywhere, as it is a non-work day.

199

Model Annex for Preparedness and Response to Radiological Transportation Incidents  

Energy.gov (U.S. Department of Energy (DOE))

This part should contain a general statement of the intent of this Annex. To provide for the planning, preparedness and coordination of emergency service efforts to respond to a transportation...

200

Modeling and Optimization for Transportation Systems Planning and Operations  

E-Print Network (OSTI)

In this paper, we focus on a number of applications of network optimization techniques to transportation systems analysis. In particular, network analysis problems, network design problems, and network management problems ...

Gartner, Nathan H.

Note: This page contains sample records for the topic "transportation greet model" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Human and modeling approaches for humanitarian transportation planning  

E-Print Network (OSTI)

Recent disasters have highlighted the need for more effective supply chain management during emergency response. Planning and prioritizing the use of trucks and helicopters to transport humanitarian aid to affected communities ...

Gralla, Erica Lynn

2012-01-01T23:59:59.000Z

202

Life Cycle Regulation of Transportation Fuels: Uncertainty and its Policy Implications  

E-Print Network (OSTI)

simply reshuffle biofuel markets . . . . . . . . . . . . .3.6. Biofuel production . . . . . . . . . . . . . . . . . .for cellulosic biofuel GWI in GREET. . . . . . . . . .

Plevin, Richard Jay

2010-01-01T23:59:59.000Z

203

Worldwide transportation/energy demand, 1975-2000. Revised Variflex model projections  

SciTech Connect

The salient features of the transportation-energy relationships that characterize the world of 1975 are reviewed, and worldwide (34 countries) long-range transportation demand by mode to the year 2000 is reviewed. A worldwide model is used to estimate future energy demand for transportation. Projections made by the forecasting model indicate that in the year 2000, every region will be more dependent on petroleum for the transportation sector than it was in 1975. This report is intended to highlight certain trends and to suggest areas for further investigation. Forecast methodology and model output are described in detail in the appendices. The report is one of a series addressing transportation energy consumption; it supplants and replaces an earlier version published in October 1978 (ORNL/Sub-78/13536/1).

Ayres, R.U.; Ayres, L.W.

1980-03-01T23:59:59.000Z

204

Development, calibration and evaluation of two mathematical models for pollutant transport in a small river  

Science Conference Proceedings (OSTI)

The present research has two main objectives (1) to build two models for concentration prediction in a stream subject to a pollutant release and (2) to investigate options for estimating the parameters of the models. The models rely on the fundamental ... Keywords: Advection-dispersion equation, Dispersion coefficient estimation, Murray Burn, Pollutant transport modelling, River water quality, Tracer experiments, Velocity estimation

Elisabeta-Cristina Ani; Steve Wallis; Andrzej Kraslawski; Paul Serban Agachi

2009-10-01T23:59:59.000Z

205

A Long-Range Transport Model for East Asia to Estimate Sulfur Deposition in Japan  

Science Conference Proceedings (OSTI)

A long-range transport model for East Asia was developed to estimate the sulfur deposition in Japan. The model is a hybrid type that combines a trajectory model for distant sources with a Eulerian model for nearby sources. The processes of ...

Yoichi Ichikawa; Hiroshi Hayami; Shin-ichi Fujita

1998-10-01T23:59:59.000Z

206

Representation of Boundary Layer Moisture Transport in Cloud-Resolving Models  

Science Conference Proceedings (OSTI)

One of the important roles of the PBL is to transport moisture from the surface to the cloud layer. However, how this transport process can be accounted for in cloud-resolving models (CRMs) is not sufficiently clear and has rarely been examined. A ...

Chin-Hoh Moeng; Akio Arakawa

2012-11-01T23:59:59.000Z

207

Computers & Geosciences 29 (2003) 351359 A case against Kd-based transport models: natural attenuation  

E-Print Network (OSTI)

)-based transport model. The study site is a contaminated groundwater aquifer underneath a uranium mill tailings prediction of the fate and transport of regulated metals and radionuclides in the subsurface of abandoned mining sites is critical to the assessment of environmental impact and to the development of effective

Polly, David

208

Generalized linear model-based expert system for estimating the cost of transportation projects  

Science Conference Proceedings (OSTI)

Timely effective cost management requires reliable cost estimates at every stage of project development. While underestimation of transportation costs seems to be a global trend, improving early cost prediction accuracy in estimates is difficult. This ... Keywords: Cost management, Expert system, Generalized linear model, Relational database, Transportation projects

Jui-Sheng Chou

2009-04-01T23:59:59.000Z

209

A 3-D hydrodynamic dispersion model for modeling tracer transport in Geothermal Reservoirs  

E-Print Network (OSTI)

diffusion of a tracer or a radionuclide. This new module ofsimulate processes of tracer/radionuclide transport using ana) a tracer or a radionuclide is present and transported

Wu, Yu-Shu; Pruess, Karsten

1998-01-01T23:59:59.000Z

210

Cathode porous transport irreversibility model for PEM fuel cell design  

Science Conference Proceedings (OSTI)

The influence is studied of slip-irreversibility at the interface between the gas diffusion layer, also referred to here as the porous transport layer, and the catalyst layer of a proton exchange membrane fuel cell (PEMFC). A two-dimensional cathode ... Keywords: catalyst layer, exergy, gas diffusion layer, slip flow irreversibility

E. O. B. Ogedengbe; M. A. Rosen

2009-02-01T23:59:59.000Z

211

Modeling diffusional transport in the interphase cell nucleus Annika Wedemeier  

E-Print Network (OSTI)

of Physics, Xiamen University, Xiamen 361005, People's Republic of China and ITPA Xiamen University, Xiamen 361005, People's Republic of China Jörg Langowski Deutsches Krebsforschungszentrum, D-69120 Heidelberg alive:1,2 Molecules transported through cell membranes, drugs on their way to their protein recep- tors

Langowski, Jörg

212

Modelling Prospects for Hydrogen-powered Transportation Until 2100  

E-Print Network (OSTI)

from transportation are: replacement of gasoline and diesel with biofuels, all-electric cars or near improvements, such as those promised by further penetration of electric­gasoline hybrid vehicles, are probably all-electric plug-in hybrids, and hydrogen fuel cell vehicles. Although large-scale

213

Modeling flow and transport in unsaturated fractured rock: An evaluation of the continuum approach  

Science Conference Proceedings (OSTI)

Because the continuum approach is relatively simple and straightforward to implement, it has been commonly used in modeling flow and transport in unsaturated fractured rock. However, the usefulness of this approach can be questioned in terms of its adequacy for representing fingering flow and transport in unsaturated fractured rock. The continuum approach thus needs to be evaluated carefully by comparing simulation results with field observations directly related to unsaturated flow and transport processes. This paper reports on such an evaluation, based on a combination of model calibration and prediction, using data from an infiltration test carried out in a densely fractured rock within the unsaturated zone of Yucca Mountain, Nevada. Comparisons between experimental and modeling results show that the continuum approach may be able to capture important features of flow and transport processes observed from the test. The modeling results also show that matrix diffusion may have a significant effect on the overall transport behavior in unsaturated fractured rocks, which can be used to estimate effective fracture-matrix interface areas based on tracer transport data. While more theoretical, numerical, and experimental studies are needed to provide a conclusive evaluation, this study suggests that the continuum approach is useful for modeling flow and transport in unsaturated, densely fractured rock.

Liu, Hui-Hai; Haukwa, Charles B.; Ahlers, C. Fredrik; Bodvarsson, Gudmundur S.; Flint, Alan L.; Guertal, William B.

2002-09-01T23:59:59.000Z

214

Seasonal Heat Transport in a Primitive Equations Model of the Tropical Indian Ocean  

Science Conference Proceedings (OSTI)

This work analyses seasonal heat transport in an ocean-only numerical simulation of the Indian Ocean forced by realistic seasonal winds and surface heat fluxes north of 15S, assuming no Indonesian Throughflow. The seasonal changes in the model ...

S. Wacongne; R. Pacanowski

1996-12-01T23:59:59.000Z

215

Technology detail in a multi-sector CGE model : transport under climate policy  

E-Print Network (OSTI)

A set of three analytical models is used to study the imbedding of specific transport technologies within a multi-sector, multi-region evaluation of constraints on greenhouse emissions. Key parameters of a computable general ...

Schafer, Andreas.

216

Aerosol Influence on Cloud Microphysics Examined by Satellite Measurements and Chemical Transport Modeling  

Science Conference Proceedings (OSTI)

Anthropogenic aerosols are hypothesized to decrease cloud drop radius and increase cloud droplet number concentration enhancing cloud optical depth and albedo. Here results have been used from a chemical transport model driven by the output of a ...

Harshvardhan; S. E. Schwartz; C. M. Benkovitz; G. Guo

2002-02-01T23:59:59.000Z

217

An Objective Method for Determining the Generalized Transport Tensor for Two-Dimensional Eulerian Models  

Science Conference Proceedings (OSTI)

An objective method for deriving the components of a generalized transport tensor for a two-dimensional model is presented. The method uses representative meridional and vertical velocities and thermodynamic scalars at a uniform grid to reduce ...

Edwin F. Danielsen

1981-07-01T23:59:59.000Z

218

Improving parameterization of scalar transport through vegetation in a coupled ecosystem-atmosphere model  

E-Print Network (OSTI)

Several regional-scale ecosystem models currently parameterize subcanopy scalar transport using a rough-wall boundary eddy diffusivity formulation. This formulation predicts unreasonably high soil evaporation beneath tall, ...

Link, Percy Anne

2008-01-01T23:59:59.000Z

219

Inversion of long-lived trace gas emissions using combined Eulerian and Lagrangian chemical transport models  

E-Print Network (OSTI)

We present a method for estimating emissions of long-lived trace gases from a sparse global network of high-frequency observatories, using both a global Eulerian chemical transport model and Lagrangian particle dispersion ...

Manning, A. J.

220

Comparisons of Transport and Dispersion Model Predictions of the URBAN 2000 Field Experiment  

Science Conference Proceedings (OSTI)

The tracer releases of the URBAN 2000 urban tracer and meteorological field experiment conducted in Salt Lake City, Utah, in October 2000 provided a wealth of data for comparison with the predictions of transport and dispersion models. ...

Steve Warner; Nathan Platt; James F. Heagy

2004-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "transportation greet model" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Underground Test Area Subproject Phase I Data Analysis Task. Volume VII - Tritium Transport Model Documentation Package  

SciTech Connect

Volume VII of the documentation for the Phase I Data Analysis Task performed in support of the current Regional Flow Model, Transport Model, and Risk Assessment for the Nevada Test Site Underground Test Area Subproject contains the tritium transport model documentation. Because of the size and complexity of the model area, a considerable quantity of data was collected and analyzed in support of the modeling efforts. The data analysis task was consequently broken into eight subtasks, and descriptions of each subtask's activities are contained in one of the eight volumes that comprise the Phase I Data Analysis Documentation.

None

1996-12-01T23:59:59.000Z

222

Time-dependent 2-D modeling of edge plasma transport with high intermittency due to blobs  

SciTech Connect

The results on time-dependent 2-D fluid modeling of edge plasmas with non-diffusive intermittent transport across the magnetic field (termed cross-field) based on the novel macro-blob approach are presented. The capability of this approach to simulate the long temporal evolution ({approx}0.1 s) of the background plasma and simultaneously the fast spatiotemporal dynamics of blobs ({approx}10{sup -4} s) is demonstrated. An analysis of a periodic sequence of many macro-blobs (PSMB) is given showing that the resulting plasma attains a dynamic equilibrium. Plasma properties in the dynamic equilibrium are discussed. In PSMB modeling, the effect of macro-blob generation frequency on edge plasma parameters is studied. Comparison between PSMB modeling and experimental profile data is given. The calculations are performed for the same plasma discharge using two different models for anomalous cross-field transport: time-average convection and PSMB. Parametric analysis of edge plasma variation with transport coefficients in these models is presented. The capability of the models to accurately simulate enhanced transport due to blobs is compared. Impurity dynamics in edge plasma with macro-blobs is also studied showing strong impact of macro-blob on profiles of impurity charge states caused by enhanced outward transport of high-charge states and simultaneous inward transport of low-charge states towards the core. Macro-blobs cause enhancement of sputtering rates, increase radiation and impurity concentration in plasma, and change erosion/deposition patterns.

Pigarov, A. Yu.; Krasheninnikov, S. I. [University of California at San Diego, La Jolla, California 92093 (United States); Rognlien, T. D. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States)

2012-07-15T23:59:59.000Z

223

Exact results for parallel-chain kinetic models of biological transport Anatoly B. Kolomeisky  

E-Print Network (OSTI)

-state models. Thus, the application of phenomenological simple chemical kinetic models20­22,25 which provide ``chemical'' approach is based on a kinetic multistate description of the molecular motor transport.17 or conformations leads to the motion of motor proteins. In the simplest chemical kinetic model see Fig. 1 , a motor

224

Evaluation of Long-Range Transport Models for Acidic Deposition in East Asia  

Science Conference Proceedings (OSTI)

A comparison between transport models is done to study the sulfur deposition in East Asia. A single-layer Lagrangian model with simple chemistry is compared to a multilayered 3D Eulerian model. The comparison is done for two-month-long episodes ...

Mahesh J. Phadnis; Gregory R. Carmichael; Yoichi Ichikawa; Hiroshi Hayami

1998-10-01T23:59:59.000Z

225

Coupling geological and numerical models to simulate groundwater flow and contaminant transport in fractured media  

Science Conference Proceedings (OSTI)

A new modeling approach is presented to improve numerical simulations of groundwater flow and contaminant transport in fractured geological media. The approach couples geological and numerical models through an intermediate mesh generation phase. As ... Keywords: Fractures, Geomodel, Influence coefficient technique, Numerical modeling, Tetrahedra

Daniela Blessent; Ren Therrien; Kerry MacQuarrie

2009-09-01T23:59:59.000Z

226

Dynamical modeling of transport in MOS structures containing silicon nanocrystals for memory applications  

Science Conference Proceedings (OSTI)

A compact model that can be used to reproduce both quasi-static and dynamic characteristics of basic MOS cells with embedded Si-nc is presented. The structure is modeled through a device-like complex matrix of tunnel junctions, resulting in a time-dependent ... Keywords: Flash memories, Nanocrystals, Nonvolatile memories, Silicon, Silicon nanocrystals, Transport modeling

Josep Carreras; O. Jambois; M. Perlvarez; Y. Lebour; B. Garrido

2008-12-01T23:59:59.000Z

227

Streamtube Fate and Transport Modeling of the Source Term for the Old Radioactive Waste  

SciTech Connect

The modeling described in this report is an extension of previous fate and transport modeling for the Old Radioactive Waste Burial Ground Corrective Measures Study/Feasibility Study. The purpose of this and the previous modeling is to provide quantitative input to the screening of remedial alternatives for the CMS/FS for this site.

Brewer, K.

2000-11-16T23:59:59.000Z

228

Analytical modelling of hydrogen transport in reactor containments  

E-Print Network (OSTI)

There are two diffusion processes, molecular and turbulent, which should be modelled in different ways. Molecular diffusion is modelled by Wilke's formula for the multi-component gas diffusion, where the diffusion constants ...

Manno, V.

1983-01-01T23:59:59.000Z

229

Proceedings: Workshop on CO2 Transport/Storage Cost Modeling  

Science Conference Proceedings (OSTI)

If reductions in CO2 emissions are needed in the utility industry, one of the potential solutions is application of CO2 capture and storage. In order to make informed decisions on applying CO2 capture and storage to the utility industry, high quality estimates of the costs are needed. While significant efforts have been made to evaluate the costs of CO2 capture from power plants, relatively little has been done to develop costs of transport and storage of CO2. This report presents the results of a worksh...

2009-03-27T23:59:59.000Z

230

TRANSPORTATION TRANSPORTATION  

E-Print Network (OSTI)

TEXASTRANS TEXAS TRANSPORTATION HALL HONOR OF HALL HONOR OF TEXASTRAN HALL HONOR OF TEXASTRAN HALL HONOR OF Inductees #12;2 TEXAS TRANSPORTATION HALL HONOR OF L NOR OF Texas is recognized as having one of the finest multimodal transportation systems in the world. The existence of this system has been key

231

Anomalous radial transport in tokamak edge plasma  

E-Print Network (OSTI)

1.2 Transport in tokamakAnomalous radial transport model for edge plasma . . . . . .Anomalous transport . . . . . . . . . . . . . . . . . . . .

Bodi, Vasudeva Raghavendra Kowsik

2010-01-01T23:59:59.000Z

232

The Seasonal Cycle of Meridional Heat Transport in a Numerical Model of the Pacific Equatorial Upwelling Zone  

Science Conference Proceedings (OSTI)

The seasonal heat transport mechanisms important in the Pacific equatorial upwelling zone are investigated using the primitive equation, reduced gravity model developed by Gent and Cane. Mechanisms of meridional heat transport are shown and ...

Esther C. Brady; Peter R. Gent

1994-12-01T23:59:59.000Z

233

A technical modeler's interface for urbansim, a system for integrated land use, transportation, and environmental modeling  

Science Conference Proceedings (OSTI)

Patterns of land use and available transportation systems play a critical role in determining the economic vitality, livability, and sustainability of urban areas. Transportation interacts strongly with land use. For example, automobile-oriented development ...

Alan Borning; Paul Waddell

2004-05-01T23:59:59.000Z

234

Lessons Learned from Alternative Transportation Fuels: Modeling Transition Dynamics  

DOE Green Energy (OSTI)

Report focuses on understanding how analytical system modeling and data from AFV experiences could improve our understanding of the dynamic forces governing the transition to a hydrogen future.

Welch, C.

2006-02-01T23:59:59.000Z

235

Modeling electron transport in the presence of electric and magnetic fields.  

SciTech Connect

This report describes the theoretical background on modeling electron transport in the presence of electric and magnetic fields by incorporating the effects of the Lorentz force on electron motion into the Boltzmann transport equation. Electromagnetic fields alter the electron energy and trajectory continuously, and these effects can be characterized mathematically by differential operators in terms of electron energy and direction. Numerical solution techniques, based on the discrete-ordinates and finite-element methods, are developed and implemented in an existing radiation transport code, SCEPTRE.

Fan, Wesley C.; Drumm, Clifton Russell; Pautz, Shawn D.; Turner, C. David

2013-09-01T23:59:59.000Z

236

Coupled Model for Heat and Water Transport in a High Level Waste Repository  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Coupled Model for Heat and Water Transport in a High Level Waste Coupled Model for Heat and Water Transport in a High Level Waste Repository in Salt Coupled Model for Heat and Water Transport in a High Level Waste Repository in Salt This report summarizes efforts to simulate coupled thermal-hydrological-chemical (THC) processes occurring within a generic hypothetical high-level waste (HLW) repository in bedded salt; chemical processes of the system allow precipitation and dissolution of salt with elevated temperatures that drive water and water vapor flow around hot waste packages. Characterizing salt backfill processes is an important objective of the exercise. An evidence-based algorithm for mineral dehydration is also applied in the modeling. The Finite Element Heat and Mass transfer code (FEHM) is used to simulate coupled thermal,

237

The Variation of Transport Through the Straits of Florida: A Barotropic Model Study  

Science Conference Proceedings (OSTI)

A high-resolution, barotropic model of the North Atlantic is used to study the variation of transport through the Straits of Florida on timescales from a few days to seasonal. The model is driven by wind and atmospheric pressure forcing derived ...

Richard J. Greatbatch; Youyu Lu; Brad DeYoung; Jimmy C. Larsen

1995-11-01T23:59:59.000Z

238

Software realization problems of mathematical models of pollutants transport in rivers  

Science Conference Proceedings (OSTI)

A software package of realization of mathematical models of pollutants transport in rivers is offered. This package is designed as a up-to-date convenient, reliable tool for specialists of various areas of knowledge such as ecology, hydrology, building, ... Keywords: Difference scheme, Mathematical model, Software package, Solution accuracy, Time of solution

K. J. Kachiashvili; D. I. Melikdzhanian

2009-10-01T23:59:59.000Z

239

Review of the shear-stress transport turbulence model experience from an industrial perspective  

Science Conference Proceedings (OSTI)

The present author was asked to provide an update on the status and the more recent developments around the shear-stress transport (SST) turbulence model for this special issue of the journal. The article is therefore not intended as a comprehensive ... Keywords: SAS, SST turbulence model, engineering flows, laminar-turbulent transition, scale-adaptive simulation, unsteady flows

Florian R. Menter

2009-04-01T23:59:59.000Z

240

Revised rail-stop exposure model for incident-free transport of nuclear waste  

SciTech Connect

This report documents a model for estimating railstop doses that occur during incident-free transport of nuclear waste by rail. The model, which has been incorporated into the RADTRAN III risk assessment code, can be applied to general freight and dedicated train shipments of waste.

Ostmeyer, R.M.

1986-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "transportation greet model" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Baseline requirements of the proposed action for the Transportation Management Division routing models  

Science Conference Proceedings (OSTI)

The potential impacts associated with the transportation of hazardous materials are important to shippers, carriers, and the general public. This is particularly true for shipments of radioactive material. The shippers are primarily concerned with safety, security, efficiency, and equipment requirements. The carriers are concerned with the potential impact that radioactive shipments may have on their operations--particularly if such materials are involved in an accident. The general public has also expressed concerns regarding the safety of transporting radioactive and other hazardous materials through their communities. Because transportation routes are a central concern in hazardous material transport, the prediction of likely routes is the first step toward resolution of these issues. In response to these routing needs, several models have been developed over the past fifteen years at Oak Ridge National Laboratory (ORNL). The HIGHWAY routing model is used to predict routes for truck transportation, the INTERLINE routing model is used to predict both rail and barge routes, and the AIRPORT locator model is used to determine airports with specified criteria near a specific location. As part of the ongoing improvement of the US Department of Energy`s (DOE) Environmental Management Transportation Management Division`s (EM-261) computer systems and development efforts, a Baseline Requirements Assessment Session on the HIGHWAY, INTERLINE, and AIRPORT models was held at ORNL on April 27, 1994. The purpose of this meeting was to discuss the existing capabilities of the models and data bases and to review enhancements of the models and data bases to expand their usefulness. The results of the Baseline Requirements Assessment Section will be discussed in this report. The discussions pertaining to the different models are contained in separate sections.

Johnson, P.E.; Joy, D.S.

1995-02-01T23:59:59.000Z

242

Phase II Contaminant Transport Parameters for the Groundwater Flow and Contaminant Transport Model of Corrective Action Unit 98: Frenchman Flat, Nye County, Nevada, Rev. No.: 0  

Science Conference Proceedings (OSTI)

This report documents pertinent transport data and data analyses as part of the Phase II Corrective Action Investigation (CAI) for Frenchman Flat (FF) Corrective Action Unit (CAU) 98. The purpose of this data compilation and related analyses is to provide the primary reference to support parameterization of the Phase II FF CAU transport model.

DeNovio, Nicole M.; Bryant, Nathan; King, Chrissi B.; Bhark, Eric; Drellack, Sigmund L.; Pickens, John F.; Farnham, Irene; Brooks, Keely M.; Reimus, Paul; Aly, Alaa

2005-04-01T23:59:59.000Z

243

Development and feasibility of a waste package coupled reactive transport model (AREST-CT)  

Science Conference Proceedings (OSTI)

Most models that analyze the waste package and engineered barrier system (near-field) of an underground geologic repository assume constant boundary conditions at the waste form surface and constant chemical properties of the groundwater. These models are useful for preliminary modeling, iterative modeling to estimate uncertainties, and as a source for a total systems analysis. However, the chemical behavior of the system is a very important factor in the containment and release of radionuclides, and one needs to understand the underlying processes involved. Therefore, the authors are developing a model to couple the calculation of the chemical properties with the reactive transport which can be used to assess the near-field. This report describes the models being implemented and presents some simple analyses demonstrating the feasibility of the chemical and coupled transport models.

Engel, D.W.; McGrail, B.P.; Fort, J.A.; Roberts, J.S.

1994-05-01T23:59:59.000Z

244

MATHEMATICAL MODELS OF THERMAL AND CHEMICAL TRANSPORT IN GEOLOGIC MEDIA  

E-Print Network (OSTI)

for Modeling Fluid and Heat Flow in Fractured Porous Media,Fluid Flow in a Single Fracture Because the topology of fractured media is different from that of porous media,

Lai, C.-H.

2010-01-01T23:59:59.000Z

245

Energy Balance Models Incorporating Transport of Thermal and Latent Energy  

Science Conference Proceedings (OSTI)

Standard latitudinally resolved energy balance models describe conservation of energy on a sphere subject to solar heating, cooling by infrared radiation and diffusive redistribution of energy according to a Fourier type heat flow with flux ...

Brian P. Flannery

1984-02-01T23:59:59.000Z

246

Horizontal Dispersion Parameters for Long-Range Transport Modeling  

Science Conference Proceedings (OSTI)

A computer model using actual meteorological data is developed to simulate the effects of wind shear on an instantaneous pollutant puff. The effect of wind shear on dispersion is obtained by subdividing, during the nocturnal phase, the previous ...

Roland R. Draxler; Albion D. Taylor

1982-03-01T23:59:59.000Z

247

Realistic modeling of chamber transport for heavy-ion fusion  

E-Print Network (OSTI)

3-m pipe lined with a molten-salt vortex to protect thesurface. This molten-salt layer is modeled as an insulatorand LiF vapor from the molten salt jets used to protect the

2003-01-01T23:59:59.000Z

248

Extended three-dimensional ADCIRC hydrodynamic model to include baroclinic flow and sediment transport  

E-Print Network (OSTI)

The objective of this research is to identify the circulation patterns of the water and sediment fluxes in coastal and estuarine zones, where the shoaling processes correlate with tide generating flow patterns. The research provides a better understanding of the characteristics of spatial and temporal variability of currents. An important deviation from previous research is the inclusion of the baroclinic term, which becomes very important in density driven flows. The understanding of this process provides a basis for determining how the water circulation three-dimensionally controls the hydrodynamics of the system and ultimately transports the suspended and soluble materials due to combined currents and waves. A three-dimensional circulation model is used to calculate the water circulation. The model is based on the three-dimensional (3D) version of Advanced Circulation (AD-CIRC) Hydrodynamic Model with extending the Sediment Transport module. The model is based on the finite element method on unstructured grids. The output of the hydrody-namic model is used to estimate spatial and temporal advections, dispersions and bottom shear stress for the erosion, suspension, deposition and transport of sediment. The model development includes extending the existing three-dimensional (3D) ADCIRC Model with (1) baroclinic forcing term and (2) transport module of suspended and soluble materials. The transport module covers the erosion, material suspension and deposition processes for both cohesive and non-cohesive type sediments. The inclusion of the baroclinic demonstrates the potential of over or underpredicting the total net transport of suspended cohesive sediment under influence of currents. The model provides less than 6% error of theoretical mass conservation for eroded, suspended and deposited sediment material. The inclusion of the baroclinic term in stratified water demonstrates the prevailing longshore sediment transport. It is shown that the model has an application to the transport of the cohesive sediments from the mouth of the Mississippi River along the north shore of the Gulf of Mexico towards and along the Texas coast. The model is also applicable to determine the design erosion thickness of a cap for isolating contaminated dredged material and to evaluate the appro-priate grain size of cap sediments to minimize the erosion.

Pandoe, Wahyu Widodo

2003-05-01T23:59:59.000Z

249

A model of hyphal tip growth involving microtubule-based transport  

E-Print Network (OSTI)

We propose a simple model for mass transport within a fungal hypha and its subsequent growth. Inspired by the role of microtubule-transported vesicles, we embody the internal dynamics of mass inside a hypha with mutually excluding particles progressing stochastically along a growing one-dimensional lattice. The connection between long range transport of materials for growth, and the resulting extension of the hyphal tip has not previously been addressed in the modelling literature. We derive and analyse mean-field equations for the model and present a phase diagram of its steady state behaviour, which we compare to simulations. We discuss our results in the context of the filamentous fungus, Neurospora crassa.

K. E. P. Sugden; M. R. Evans; W. C. K. Poon; N. D. Read

2006-05-09T23:59:59.000Z

250

Conceptual model for regional radionuclide transport from a salt dome repository: a technical memorandum  

Science Conference Proceedings (OSTI)

Disposal of high-level radioactive wastes is a major environmental problem influencing further development of nuclear energy in this country. Salt domes in the Gulf Coast Basin are being investigated as repository sites. A major concern is geologic and hydrologic stability of candidate domes and potential transport of radionuclides by groundwater to the biosphere prior to their degradation to harmless levels of activity. This report conceptualizes a regional geohydrologic model for transport of radionuclides from a salt dome repository. The model considers transport pathways and the physical and chemical changes that would occur through time prior to the radionuclides reaching the biosphere. Necessary, but unknown inputs to the regional model involve entry and movement of fluids through the repository dome and across the dome-country rock interface and the effect on the dome and surrounding strata of heat generated by the radioactive wastes.

Kier, R.S.; Showalter, P.A.; Dettinger, M.D.

1980-05-30T23:59:59.000Z

251

Heat Transport in Groundwater Systems--Finite Element Model  

E-Print Network (OSTI)

Solar energy is a promising alternate energy source for space heating. A method of economic long term solar energy storage is needed. Researchers have proposed storing solar energy by injecting hot water heated using solar collectors into groundwater aquifers for long term energy storage. Analytical solutions are available that predict water temperatures as hot water is injected into a groundwater aquifer, but little field and laboratory data are available to verify these models. The objectives of this study were to construct a laboratory model to simulate hot water injection into a confined aquifer, to use data from the model to verify analytical solutions modeling this process, and to evaluate the effects of physical properties and design parameters on thermal recovery efficiency. Initial studies of hot water injection into underground reservoirs were done by the petroleum industry while studying secondary and tertiary oil recovery methods. These studies involved small laboratory models. Advances in computer technology made it possible to model these systems numerically. Many assumptions must be made to predict temperature distributions and thermal efficiencies using analytical models which are not required in numerical solutions. To simulate hot water injection into a confined aquifer, a laboratory model (a 1.8288 m deep, 0.2 radian sector tank, that was 7.01 m in the radial direction) was constructed. There were 39 temperature and 15 fluid pressure measuring locations through the model. Water was supplied to the model at a constant temperature and flow rate. The flow layer was composed of a fine grained Texblast blasting sand. Four runs were made. During the initial run, no heat transfer took place and the hydraulic conductivity was measured. Three runs were made where the heat transfer was monitored. Water level data from the heat transfer runs showed that as the temperature of the aquifer increased, the hydraulic conductivity increased. Temperature data indicated that the three radii closest to the well bore reached thermal equilibrium. The equilibrium temperature decreased as radius increased. From Run 1 to Run 2, the equilibrium temperature increased at each radius because a larger flow rate was used. A vertical thermal gradient existed in the flow layer with the less dense warm water floating out over the cooler more dense water initially in the model. During the pumping cycle, the temperatures gradually decreased. The temperature of the water as it was pumped out of the model was measured and the energy recovered was computed using the initial temperature as a reference. Various other temperatures were used as a base reference to calculate recovery efficiency. There were heat losses out the sides of the model. The assumption of angular symmetry made in all analytical solutions was therefore not met. For this reason, the analytical solutions showed adequate, but not great, agreement with the experimental temperature distributions. Using the analytical solutions, the effects of changing system design parameters were evaluated. Increasing thermal conductivity in the flow layer caused the temperature distribution to spread out but had no effect on thermal efficiency. Increasing the thermal conductivity in the confining layers caused the temperature profile to not move as far from the well, and decreased thermal efficiency. Injection rates are only indirectly related to thermal efficiency. The physical parameter having the greatest effect on thermal efficiency was the flow layer thickness. As thickness increased, thermal efficiency increased.

Grubaugh, E. K.; Reddell, D. L.

1980-08-01T23:59:59.000Z

252

Gas transport model for chemical vapor infiltration. Topical report  

Science Conference Proceedings (OSTI)

A node-bond percolation model is presented for the gas permeability and pore surface area of the coarse porosity in woven fiber structures during densification by chemical vapor infiltration (CVI). Model parameters include the number of nodes per unit volume and their spatial distribution, and the node and bond radii and their variability. These parameters relate directly to structural features of the weave. Some uncertainty exists in the proper partition of the porosity between {open_quotes}node{close_quotes} and{open_quote}bond{close_quotes} and between intra-tow and inter-tow, although the total is constrained by the known fiber loading in the structure. Applied to cloth layup preforms the model gives good agreement with the limited number of available measurements.

Starr, T.L. [Georgia Institute of Technology, Atlanta, GA (United States). School of Materials Science and Engineering

1995-05-01T23:59:59.000Z

253

Lattice-gas model for active vesicle transport by molecular motors with opposite polarities  

E-Print Network (OSTI)

We introduce a multi-species lattice gas model for motor protein driven collective cargo transport on cellular filaments. We use this model to describe and analyze the collective motion of interacting vesicle cargoes being carried by oppositely directed molecular motors, moving on a single biofilament. Building on a totally asymmetric exclusion process (TASEP) to characterize the motion of the interacting cargoes, we allow for mass exchange with the environment, input and output at filament boundaries and focus on the role of interconversion rates and how they affect the directionality of the net cargo transport. We quantify the effect of the various different competing processes in terms of non-equilibrium phase diagrams. The interplay of interconversion rates, which allow for flux reversal and evaporation/deposition processes introduce qualitatively new features in the phase diagrams. We observe regimes of three-phase coexistence, the possibility of phase re-entrance and a significant flexibility in how the different phase boundaries shift in response to changes in control parameters. The moving steady state solutions of this model allows for different possibilities for the spatial distribution of cargo vesicles, ranging from homogeneous distribution of vesicles to polarized distributions, characterized by inhomogeneities or {\\it shocks}. Current reversals due to internal regulation emerge naturally within the framework of this model. We believe this minimal model will clarify the understanding of many features of collective vesicle transport, apart from serving as the basis for building more exact quantitative models for vesicle transport relevant to various {\\it in-vivo} situations.

Sudipto Muhuri; Ignacio Pagonabarraga

2010-09-09T23:59:59.000Z

254

Transport modeling of ECH and neutral-beam-heated plasmas in the advanced toroidal facility  

SciTech Connect

Results of time-dependent transport modeling of the ATF plasmas are compared with a typical ungettered, neutral-beam-heated discharge. A summary of ATF machine parameters is given by Murakami. The model is adjusted to give agreement between measured diagnostics signals and the corresponding values inferred from the model plasma. With this agreement, the main features of the discharge are reproduced including the radiation-induced temperature collapse. 7 refs., 6 figs.

Howe, H.C.; Horton, L.D.; Crume, E.C.; Harris, J.H.; Isler, R.C.; Wilgen, J.B.; Wing, W.R.

1989-01-01T23:59:59.000Z

255

STEADY STATE MODEL OF HYDROGEN INFRASTRUCTURE FOR US URBAN Christopher Yang and Joan M. Ogden  

E-Print Network (OSTI)

production from a number of feedstocks including coal, natural gas, biomass and electrolysis, hydrogen a little differently than other energy resources. While natural gas, coal, electricity and diesel and feedstocks (coal, natural gas and diesel) are obtained from the GREET model [19, 20]. However

California at Davis, University of

256

The Transportation Revenue Estimator and Needs Determination System (TRENDS) Model  

E-Print Network (OSTI)

.......................................................... 15 3.3 Indexing the Motor Fuels Tax, inflation rates, taxes, fees and other elements. The output is a set of tables and graphs showing a forecast................................................................................................. 12 TRENDS Model Revenue Enhancements Tab 3.1 State Gasoline and Diesel Fuel Variables

257

Transported PDF Modeling of Nonpremixed Turbulent CO/H-2/N-2 Jet Flames  

Science Conference Proceedings (OSTI)

Turbulent CO/H{sub 2}/N{sub 2} (syngas) flames are simulated using a transported composition probability density function (PDF) method. A consistent hybrid Lagrangian particle/Eulerian mesh algorithm is used to solve the modeled PDF transport equation. The model includes standard k? turbulence, gradient transport for scalars, and Euclidean minimum spanning tree (EMST) mixing. Sensitivities of model results to variations in the turbulence model, the treatment of radiation heat transfer, the choice of chemical mechanism, and the PDF mixing model are explored. A baseline model reproduces the measured mean and rms temperature, major species, and minor species profiles reasonably well, and captures the scaling that is observed in the experiments. Both our results and the literature suggest that further improvements can be realized with adjustments in the turbulence model, the radiation heat transfer model, and the chemical mechanism. Although radiation effects are relatively small in these flames, consideration of radiation is important for accurate NO prediction. Chemical mechanisms that have been developed specifically for fuels with high concentrations of CO and H{sub 2} perform better than a methane mechanism that was not designed for this purpose. It is important to account explicitly for turbulencechemistry interactions, although the details of the mixing model do not make a large difference in the results, within reasonable limits.

Zhao, xinyu; Haworth, D. C.; Huckaby, E. David

2012-01-01T23:59:59.000Z

258

Simulating Aerosols Using a Chemical Transport Model with Assimilation of Satellite Aerosol Retrievals: Methodology for INDOEX  

E-Print Network (OSTI)

A system for simulating aerosols has been developed using a chemical transport model together with an assimilation of satellite aerosol retrievals. The methodology and model components are described in this paper, and the modeled distribution of aerosols for the Indian Ocean Experiment (INDOEX) is presented by Rasch et al. [this issue]. The system generated aerosol forecasts to guide deployment of ships and aircraft during INDOEX. The system consists of the Model of Atmospheric Transport and Chemistry (MATCH) combined with an assimilation package developed for applications in atmospheric chemistry. MATCH predicts the evolution of sulfate, carbonaceous, and mineral dust aerosols, and it diagnoses the distribution of sea salt aerosols. The model includes a detailed treatment of the sources, chemical transformation, transport, and deposition of the aerosol species. The aerosol forecasts involve a two-stage process. During the assimilation phase the total column aerosol optical depth (AOD) is estimated from the model aerosol fields. The model state is then adjusted to improve the agreement between the simulated AOD and satellite retrievals of AOD. During the subsequent integration phase the aerosol fields are evolved using meteorological fields from an external model. Comparison of the modeled AOD against estimates of the AOD from INDOEX Sun photometer data show that the differences in daily means are #0.03 # 0.06. Although the initial application is limited to the Indian Ocean, the methodology could be extended to derive global aerosol analyses combining in situ and remotely sensed aerosol observations.

William D. Collins; Phillip J. Rasch; Brian E. Eaton; Boris V. Khattatov; Jean-francois Lamarque; C. Zender

2001-01-01T23:59:59.000Z

259

Analytical risk-based model of gaseous and liquid-phase radon transport in landfills with radium sources  

Science Conference Proceedings (OSTI)

An analytical model of gaseous and liquid-phase radon transport through soils is derived for environmental modeling of landfills containing uranium mill tailings or Ra-226 sources. Processes include radon diffusion in both the gas and liquid phases, ... Keywords: Landfill, Multiphase, Performance assessment, Probabilistic modeling, Radium, Radon, Transport

Clifford K. Ho

2008-09-01T23:59:59.000Z

260

Recent Improvements to an Advanced Atmospheric Transport Modeling System  

SciTech Connect

The Atmospheric Technologies Group (ATG) has developed an advanced atmospheric modeling capability using the Regional Atmospheric Modeling System (RAMS) and a stochastic Lagrangian particle dispersion model (LPDM) for operational use at the Savannah River Site (SRS). For local simulations concerning releases from the Central Savannah River Area (CSRA), RAMS is run in a nested grid configuration with horizontal grid spacing of 8 and 2 km for each grid, with 6-hr forecasts updated every 3 hours. An interface to allow for easy user access to LPDM had been generated, complete with post-processing results depicting surface concentration, deposition, and a variety of dose quantities. A prior weakness in this approach was that observations from the SRS tower network were only incorporated into the three-dimensional modeling effort during the initialization process. Thus, if the forecasted wind fields were in error, the resulting plume predictions would also be erroneous. To overcome this shortcoming, the procedure for generating RAMS wind fields and reading them into LPDM has been modified such that SRS wind measurements are blended with the predicted three-dimensional wind fields from RAMS using the Barnes technique. In particular, the horizontal components in RAMS are replaced with the observed values at a series of 8 towers that exist within the SRS boundary (covering {approx}300 km{sup 2}). Even though LPDM is currently configured to account only for radioactive releases, it was used in a recent chlorine gas release to generate plume concentrations based on unit releases from the site of a train accident in Graniteville, South Carolina. This information was useful to local responders as an indication of potential protective actions downwind of the release.

Buckley, R. L.; Hunter, C. H.

2005-10-24T23:59:59.000Z

Note: This page contains sample records for the topic "transportation greet model" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Modeling engine oil vaporization and transport of the oil vapor in the piston ring pack on internal combustion engines.  

E-Print Network (OSTI)

??A model was developed to study engine oil vaporization and oil vapor transport in the piston ring pack of internal combustion engines. With the assumption (more)

Cho, Yeunwoo, 1973-

2004-01-01T23:59:59.000Z

262

Geochemistry, Fate, and Three-Dimensional Transport Modeling of Subsurface Cyanide Contamination at a Manufactured Gas Plant  

Science Conference Proceedings (OSTI)

This report documents the geochemistry, fate, and three-dimensional transport modeling of subsurface cyanide contamination at a manufactured gas plant.

2001-01-26T23:59:59.000Z

263

Transport of Molecular Motor Dimers in Burnt-Bridge Models  

E-Print Network (OSTI)

Dynamics of molecular motor dimers, consisting of rigidly bound particles that move along two parallel lattices and interact with underlying molecular tracks, is investigated theoretically by analyzing discrete-state stochastic continuous-time burnt-bridge models. In these models the motion of molecular motors is viewed as a random walk along the lattices with periodically distributed weak links (bridges). When the particle crosses the weak link it can be destroyed with a probability $p$, driving the molecular motor motion in one direction. Dynamic properties and effective generated forces of dimer molecular motors are calculated exactly as a function of a concentration of bridges $c$ and burning probability $p$ and compared with properties of the monomer motors. It is found that the ratio of the velocities of the dimer and the monomer can never exceed 2, while the dispersions of the dimer and the monomer are not very different. The relative effective generated force of the dimer (as compared to the monomer) also cannot be larger than 2 for most sets of parameters. However, a very large force can be produced by the dimer in the special case of $c=1/2$ for non-zero shift between the lattices. Our calculations do not show the significant increase in the force generated by collagenase motor proteins in real biological systems as predicted by previous computational studies. The observed behavior of dimer molecular motors is discussed by considering in detail the particle dynamics near burnt bridges.

Alexander Yu. Morozov; Anatoly B. Kolomeisky

2007-09-21T23:59:59.000Z

264

Reaction-based reactive transport modeling of Fe(III)  

Science Conference Proceedings (OSTI)

This research project (started Fall 2004) was funded by a grant to Argonne National Laboratory, The Pennsylvania State University, and The University of Alabama in the Integrative Studies Element of the NABIR Program (DE-FG04-ER63914/63915/63196). Dr. Eric Roden, formerly at The University of Alabama, is now at the University of Wisconsin, Madison. Our project focuses on the development of a mechanistic understanding and quantitative models of coupled Fe(III)/U(VI) reduction in FRC Area 2 sediments. This work builds on our previous studies of microbial Fe(III) and U(VI) reduction, and is directly aligned with the Scheibe et al. NABIR FRC Field Project at Area 2.

Kemner, K.M.; Kelly, S.D.; Burgos, Bill; Roden, Eric

2006-06-01T23:59:59.000Z

265

A Lagrangian Model of Long-Range Transport of Sulphur with the Diurnal Variations of Some Model Parameters  

Science Conference Proceedings (OSTI)

A Lagrangian receptor-oriented one-layer model has been developed in order to simulate a synoptic-scale transport of airborne sulphur on a daily basis. Mass balance equations for sulphur dioxide and particulate sulphate were integrated along 3-...

Zvjewana Klai?

1996-04-01T23:59:59.000Z

266

Relations between Northward Ocean and Atmosphere Energy Transports in a Coupled Climate Model  

Science Conference Proceedings (OSTI)

The Third Hadley Centre Coupled OceanAtmosphere General Circulation Model (HadCM3) is used to analyze the relation between northward energy transports in the ocean and atmosphere at centennial time scales. In a transient water-hosing experiment, ...

Michael Vellinga; Peili Wu

2008-02-01T23:59:59.000Z

267

Accessibility analysis and modelling in public transport networks: a raster based approach  

Science Conference Proceedings (OSTI)

Accessibility is an important factor in the development of land-use patterns and urban settlements, and these two components are considered linked close together. With the increasing attention payed to reduction of CO2 emissions, focus has been turned ... Keywords: GIS, accessibility, public transportation, raster-based modelling

Morten Fuglsang; Henning Sten Hansen; Bernd Mnier

2011-06-01T23:59:59.000Z

268

Using reactive transport modeling to evaluate the source term at Yucca mountain  

Science Conference Proceedings (OSTI)

The conventional approach of source-term evaluation for performance assessment of nuclear waste repositories uses the dissolution rate of waste form and the solubility of pure phases of radioactive elements to constrain radionuclide concentrations. This ... Keywords: neptunium, nuclear waste, radionuclide solubility, reactive-transport modeling, secondary phases, spent nuclear fuel, uranium

Yueting Chen

2003-04-01T23:59:59.000Z

269

Transport Modeling of Reactive and Non-Reactive Constituents from Summitville,  

E-Print Network (OSTI)

Survey (USGS) began water- quality investigations at Summitville, Terrace #12;Figure 2. Aerial photographTransport Modeling of Reactive and Non- Reactive Constituents from Summitville, Colorado in the Wightman Fork/Alamosa River system downstream of the Summitville Mine, south-central Colorado, were

270

Multicomponent reactive transport modeling at the Ratones uranium mine, Cceres (Spain)  

E-Print Network (OSTI)

management. The Ratones uranium mine was abandoned and flooded in 1974. Due to its reducing undergroundMulticomponent reactive transport modeling at the Ratones uranium mine, Cáceres (Spain) Modelación/06/05 / Accepted: 02/10/05 Abstract Flooding of abandoned mines may have a major impact in groundwater quality

Politècnica de Catalunya, Universitat

271

Modelling uncertainty in the sustainability of Intelligent Transport Systems for highways using probabilistic data fusion  

Science Conference Proceedings (OSTI)

The implementation of ITS to increase the efficiency of saturated highways has become increasingly prevalent. It is a high level objective for many international governments and operators that highways should be managed in a way that is both sustainable ... Keywords: Intelligent Transport Systems, Low carbon-energy policy, Uncertainty modelling

Ben Kolosz, Susan Grant-Muller, Karim Djemame

2013-11-01T23:59:59.000Z

272

A screening model for simulating DNAPL flow and transport in porous media: theoretical development  

Science Conference Proceedings (OSTI)

In the last two decades there has been an increased awareness of the contamination of groundwater due to the presence of denser-than-water nonaqueous phase liquids (DNAPLs). Numerous theoretical, experimental and numerical investigations have been conducted ... Keywords: Contaminant transport, Multiphase flow, Screening model

Clinton S. Willson; James W. Weaver; Randall J. Charbeneau

2006-01-01T23:59:59.000Z

273

Ocean Heat Transport, Sea Ice, and Multiple Climate States: Insights from Energy Balance Models  

Science Conference Proceedings (OSTI)

Several extensions of energy balance models (EBMs) are explored in which (i) sea ice acts to insulate the atmosphere from the ocean and (ii) ocean heat transport is allowed to have some meridional structure controlled by the wind, with minima at ...

Brian E. J. Rose; John Marshall

2009-09-01T23:59:59.000Z

274

Preface: Nonclassical Transport  

E-Print Network (OSTI)

models of solute transport in highly heterogeneous geologicSemenov. 2008b. Nonclassical transport processes in geologicand L. Matveev. 2008. Transport regimes and concentration

Bolshov, L.

2010-01-01T23:59:59.000Z

275

Some thermal transport properties of the FPU model with quadratic pinning  

E-Print Network (OSTI)

Thermal transport properties of the FPU $\\beta$ model with a quadratic pinning term are investigated for various couplings and temperatures. In particular, the size dependence of the thermal conductivity, $\\kappa\\propto L^\\alpha$, is studied. $\\alpha$ agrees with that of the FPU $\\beta$ model (with no pinning) at high temperatures but decreases at low temperatures. This crossover behavior occurs at a temperature depending on the strength of the quadratic pinning.

Kenichiro Aoki

2008-01-02T23:59:59.000Z

276

Verifying the Accuracy of Land Use Models Used in Transportation and Air Quality: A Case Study in the Sacramento, California Region  

E-Print Network (OSTI)

simulations for a future transportation plan that uses fixedfuture regional land use projections and transportationFutures for Tansportation and Land UseIntegrated Models Contrasted with Trend Delphi Methods: The Portland Metro Results, Transportation

Rodier, Caroline J.

2005-01-01T23:59:59.000Z

277

Uncertainty Analysis Framework - Hanford Site-Wide Groundwater Flow and Transport Model  

Science Conference Proceedings (OSTI)

Pacific Northwest National Laboratory (PNNL) embarked on a new initiative to strengthen the technical defensibility of the predictions being made with a site-wide groundwater flow and transport model at the U.S. Department of Energy Hanford Site in southeastern Washington State. In FY 2000, the focus of the initiative was on the characterization of major uncertainties in the current conceptual model that would affect model predictions. The long-term goals of the initiative are the development and implementation of an uncertainty estimation methodology in future assessments and analyses using the site-wide model. This report focuses on the development and implementation of an uncertainty analysis framework.

Cole, Charles R.; Bergeron, Marcel P.; Murray, Christopher J.; Thorne, Paul D.; Wurstner, Signe K.; Rogers, Phillip M.

2001-11-09T23:59:59.000Z

278

Cloud-radiative effects on implied oceanic energy transports as simulated by atmospheric general circulation models  

DOE Green Energy (OSTI)

This paper reports on energy fluxes across the surface of the ocean as simulated by fifteen atmospheric general circulation models in which ocean surface temperatures and sea-ice boundaries are prescribed. The oceanic meridional energy transport that would be required to balance these surface fluxes is computed, and is shown to be critically sensitive to the radiative effects of clouds, to the extent that even the sign of the Southern Hemisphere ocean energy transport can be affected by the errors in simulated cloud-radiation interactions.

Gleckler, P.J. [Lawrence Livermore National Lab., CA (United States); Randall, D.A. [Colorado State Univ., Fort Collins, CO (United States); Boer, G. [Canadian Climate Centre, Victoria (Canada)

1994-03-01T23:59:59.000Z

279

Leaking method approach to surface transport in the Mediterranean Sea from a numerical ocean model  

E-Print Network (OSTI)

We use Lagrangian diagnostics (the leaking and the exchange methods) to characterize surface transport out of and between selected regions in the Western Mediterranean. Velocity fields are obtained from a numerical model. Residence times of water of Atlantic origin in the Algerian basin, with a strong seasonal dependence, are calculated. Exchange rates between these waters and the ones occupying the northern basin are also evaluated. At surface, northward transport is dominant, and involves filamental features and eddy structures that can be identified with the Algerian eddies. The impact on these results of the presence of small scale turbulent motions is evaluated by adding Lagrangian diffusion.

Judit Schneider; Vicente Fernandez; Emilio Hernandez-Garcia

2004-10-01T23:59:59.000Z

280

A critical view on transport and entanglement in models of photosynthesis  

E-Print Network (OSTI)

Quantum effects in biological light-harvesting molecules, such as quantum coherence of excitonic states and entanglement have recently gained much attention. We observe a certain discrepancy between the original experimental work and several theoretical treatments of coherent excitation transport in light-harvesting molecules. Contrary to what is generally stated, we argue that entanglement in such molecules is generally not equivalent to the presence of coherence but mostly introduced by initial assumptions underlying the models, and that entanglement, as opposite to coherence, seems to play no role in the transport efficiency.

Tiersch, Markus; Briegel, Hans J

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "transportation greet model" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Analysis of Passive Tracer Transport as Modeled by an Atmospheric General Circulation Model  

Science Conference Proceedings (OSTI)

Tracers without feedback on the atmosphere are used to probe tropospheric transport. Such passive tracers are considered for two important anthropogenic sources, Europe and eastern North America. The linearity of passive tracer continuity allows ...

Mark Holzer

1999-06-01T23:59:59.000Z

282

Modeling the global freight transportation system: a multi-level modeling perspective  

Science Conference Proceedings (OSTI)

The interconnectedness of different actors in the global freight transportation industry has rendered such a system as a large complex system where different sub-systems are interrelated. On such a system, policy-related- exploratory analyses which have ...

Ronald Apriliyanto Halim; Lorant A. Tavasszy; Mamadou D. Seck

2012-12-01T23:59:59.000Z

283

Efficient Numerical Methods for an Anisotropic, Nonisothermal, Two-Phase Transport Model of Proton Exchange Membrane Fuel Cell  

Science Conference Proceedings (OSTI)

We carry out model and numerical studies for a three-dimensional, anisotropic, nonisothermal, two-phase steady state transport model of proton exchange membrane fuel cell (PEMFC) in this paper. Besides fully addressing the conservation equations of mass, ... Keywords: Anisotropy, Combined finite element-upwind finite volume, Kirchhoff transformation, Newton's linearization, Nonisothermality, Proton exchange membrane fuel cell (PEMFC), Two-phase transport

Pengtao Sun

2012-04-01T23:59:59.000Z

284

Modeling engine oil vaporization and transport of the oil vapor in the piston ring pack on internal combustion engines  

E-Print Network (OSTI)

A model was developed to study engine oil vaporization and oil vapor transport in the piston ring pack of internal combustion engines. With the assumption that the multi-grade oil can be modeled as a compound of several ...

Cho, Yeunwoo, 1973-

2004-01-01T23:59:59.000Z

285

Inert Trace Constituent Transport in Sigma and Hybrid IsentropicSigma Models. Part I: Nine Advection Algorithms  

Science Conference Proceedings (OSTI)

The University of Wisconsin hybrid isentropicsigma (??) coordinate channel model and the nominally identical sigma (?) model are used to test the relative capabilities of nine trace constituent transport algorithms. The nine are standard ...

Fred M. Reames; Tom H. Zapotocny

1999-02-01T23:59:59.000Z

286

Carlsbad Area Office unveils full-scale model of new WIPP waste transportation cask  

NLE Websites -- All DOE Office Websites (Extended Search)

Carlsbad Area Office Unveils Full-Scale Model Carlsbad Area Office Unveils Full-Scale Model Of New WIPP Waste Transportation Cask CARLSBAD, N.M., February 23, 2000 - The U.S. Department of Energy's (DOE) Carlsbad Area Office today unveiled a full-scale model of its newest waste transportation cask, the RH-72B, during a ceremony at the local DOE offices. "This is another milestone for the Department of Energy," said Dr. Inés Triay, Manager of the Carlsbad Area Office, describing the importance of the new container for those attending the ceremony. "After we receive approval from the U.S. Nuclear Regulatory Commission (NRC), we plan to add the RH-72B to our fleet, which will help the Department meet its continuing mission to remove transuranic waste from the accessible environment and

287

Incorporating Radiation Effects into Edge Plasma Transport Models with Extended Atomic Data Tables  

DOE Green Energy (OSTI)

Plasmas at the tokamak edge can be very optically thick to hydrogen resonance lines. The resulting strong line radiation can significantly affect the ionization and energy balance in these plasmas. One method of account for effects is to self-consistently couple a partially ionized plasma transport model with a nonlocal thermodynamic equilibrium (NLTE) model incorporating line radiation transfer. This approach has been implemented in one dimension, but would be computationally challenging and expensive to implement in multiple dimensions. Approximate treatments of radiation transfer can decrease the computational time, but would still require coupling to a multidimensional plasma transport model to address realistic geometries, e.g. the tokamak divertor. Here, we consider the development of atomic hydrogen data tables that include radiation interactions and can be easily applied to multidimensional geometries.

Scott, H A; Adams, M L

2004-06-14T23:59:59.000Z

288

Pore-Scale Modeling of Two-Phase Transport in Polymer Electrolyte Fuel Cells - Progress and Perspective  

Science Conference Proceedings (OSTI)

Recent years have witnessed an explosion of research and development efforts in the area of polymer electrolyte fuel cells (PEFC), perceived as the next generation clean energy source for automotive, portable and stationary applications. Despite significant progress, a pivotal performance/durability limitation in PEFCs centers on two-phase transport and mass transport loss originating from suboptimal liquid water transport and flooding phenomena. Liquid water blocks the porous pathways in the gas diffusion layer (GDL) and the catalyst layer (CL), thus hindering oxygen transport from the flow field to the electrochemically actives sites in the catalyst layer. Different approaches have been examined to model the underlying transport mechanisms in the PEFC with different levels of complexities. Due to the macroscopic nature, these two-phase models fail to resolve the underlying structural influence on the transport and performance. Mesoscopic modeling at the pore-scale offers great promise in elucidating the underlying structure-transport-performance interlinks in the PEFC porous components. In this article, a systematic review of the recent progress and prospects of pore-scale modeling in the context of two-phase transport in the PEFC is presented. Specifically, the efficacy of lattice Boltzmann (LB), pore morphology (PM) and pore network (PN) models coupled with realistic delineation of microstructures in fostering enhanced insight into the underlying liquid water transport in the PEFC GDL and CL is highlighted.

Mukherjee, Partha P [ORNL

2010-01-01T23:59:59.000Z

289

Directed transport in equilibrium : analysis of the dimer model with inertial terms  

E-Print Network (OSTI)

We have previously shown an analysis of our dimer model in the over-damped regime to show directed transport in equilibrium. Here we analyze the full model with inertial terms present to establish the same result. First we derive the Fokker-Planck equation for the system following a Galilean transformation to show that a uniformly translating equilibrium distribution is possible. Then, we find out the velocity selection for the centre of mass motion using that distribution on our model. We suggest generalization of our calculations for soft collision potentials and indicate to interesting situation with possibility of oscillatory non-equilibrium state within equilibrium.

A. Bhattacharyay

2011-08-15T23:59:59.000Z

290

Conceptual model for regional radionuclide transport from a basalt repository site. Final draft, technical memorandum  

SciTech Connect

This technical memorandum was prepared to: (1) describe a typical basalt radionuclide repository site, (2) describe geologic and hydrologic processes associated with regional radionuclide transport in basalts, (3) define the parameters required to model regional radionuclide transport from a basalt repository site, and (4) develop a ''conceptual model'' of radionuclide transport from a basalt repository site. In a general hydrological sense, basalts may be described as layered sequences of aquifers and aquitards. The Columbia River Basalt, centered near the semi-arid Pasco Basin, is considered by many to be typical basalt repository host rock. Detailed description of the flow system including flow velocities with high-low hydraulic conductivity sequences are not possible with existing data. However, according to theory, waste-transport routes are ultimately towards the Columbia River and the lengths of flow paths from the repository to the biosphere may be relatively short. There are many physical, chemical, thermal, and nuclear processes with associated parameters that together determine the possible pattern of radionuclide migration in basalts and surrounding formations. Brief process descriptions and associated parameter lists are provided. Emphasis has been placed on the use of the distribution coefficient in simulating ion exchange. The use of the distribution coefficient approach is limited because it takes into account only relatively fast mass transfer processes. In general, knowledge of hydrogeochemical processes is primitive.

Walton, W.C.; Voorhees, M.L.; Prickett, T.A.

1980-05-23T23:59:59.000Z

291

Modeling transport and deposition of level 1 substances to the great lakes  

E-Print Network (OSTI)

of Persistence and Long-Range Transport Potential amongassessment of potential for transport and deposition to theE. "Assessing Long-Range Transport Potential of Persistent

MacLeod, Matthew; Riley, William J.; McKone, Thomas E.

2005-01-01T23:59:59.000Z

292

Transportation Models In the Policy-Making Process: Uses, Misuses, And Lessons For The Future  

E-Print Network (OSTI)

of alternative futures and how transportation decisions36 Panel 5: Future Innovations in TransportationForum Panel 5 Future Innovations in Transportation Analysis

Brinkman, Anthony; Goldman, Todd

1998-01-01T23:59:59.000Z

293

Transport coefficients from the Nambu-Jona-Lasinio model for $SU(3)_f$  

E-Print Network (OSTI)

We calculate the shear $\\eta(T)$ and bulk viscosities $\\zeta(T)$ as well as the electric conductivity $\\sigma_e(T)$ and heat conductivity $\\kappa(T)$ within the Nambu-Jona-Lasinio model for 3 flavors as a function of temperature as well as the entropy density $s(T)$, pressure $P(T)$ and speed of sound squared $c_s^2(T)$. We compare the results with other models such as the Polyakov-Nambu-Jona-Lasinio (PNJL) model and the dynamical quasiparticle model (DQPM) and confront these results with lattice QCD data whenever available. We find the NJL model to have a limited predictive power for the thermodynamic variables and various transport coefficients above the critical temperature whereas the PNJL model and DQPM show acceptable results for the quantities of interest.

Rudy Marty; Elena Bratkovskaya; Wolfgang Cassing; Jrg Aichelin; Hamza Berrehrah

2013-11-13T23:59:59.000Z

294

Transport coefficients from the Nambu-Jona-Lasinio model for $SU(3)_f$  

E-Print Network (OSTI)

We calculate the shear $\\eta(T)$ and bulk viscosities $\\zeta(T)$ as well as the electric conductivity $\\sigma_e(T)$ and heat conductivity $\\kappa(T)$ within the Nambu-Jona-Lasinio model for 3 flavors as a function of temperature as well as the entropy density $s(T)$, pressure $P(T)$ and speed of sound $c_s^2(T)$. We compare the results with other models such as the Polyakov-Nambu-Jona-Lasinio (PNJL) model and the dynamical quasiparticle model (DQPM) and confront these results with lattice QCD data whenever available. We find the NJL model to have a limited predictive power for the thermodynamic variables and various transport coefficients above the critical temperature whereas the PNJL model and DQPM show acceptable results for the quantities of interest.

Rudy Marty; Elena Bratkovskaya; Wolfgang Cassing; Jrg Aichelin; Hamza Berrehrah

2013-05-30T23:59:59.000Z

295

Delocalized and Resonant Quantum Transport in Nonlinear Generalizations of the Kicked Rotor Model  

E-Print Network (OSTI)

We analyze the effects of a nonlinear cubic perturbation on the delta-Kicked Rotor. We consider two different models, in which the nonlinear term acts either in the position or in the momentum representation. We numerically investigate the modifications induced by the nonlinearity in the quantum transport in both localized and resonant regimes and a comparison between the results for the two models is presented. Analyzing the momentum distributions and the increase of the mean square momentum, we find that the quantum resonances asymptotically are very stable with respect to the nonlinear perturbation of the rotor's phase evolution. For an intermittent time regime, the nonlinearity even enhances the resonant quantum transport, leading to superballistic motion.

Laura Rebuzzini; Sandro Wimberger; Roberto Artuso

2004-10-12T23:59:59.000Z

296

A computer model of gas generation and transport within TRU waste drums  

DOE Green Energy (OSTI)

A computer model has been developed to predict radiolytic gas generation and transport within Transuranic (TRU) waste drums and surrounding enclosures. Gas generation from the radiolytic decomposition of organic material contaminated with plutonium is modeled and the concentrations of gas throughout the waste drum and enclosures are determined using a diffusional transport model. The model accurately reproduces experimentally measured gas concentrations. With polyethylene waste in unvented drums, the model predicts that the concentration of hydrogen gas can exceed 4 mole percent (lower flammable limit) with only about 5 curies of plutonium. If the drum liner is punctured and an unrestricted 0.75-in. carbon composite filter vent is installed in the drum lid, the plutonium loading can be increased to 240 Ci without generating flammable gas mixtures. Larger diameter filters can be used to increase the curie loading. The model has been used to show that shipments of 1000 Ci of plutonium-238 contaminated waste from Savannah River to the WIPP site are feasible using the TRUPACT shipping container. 10 refs., 17 figs., 6 tabs.

Smith, F.G. III

1988-06-01T23:59:59.000Z

297

Final Report Coupling in silico microbial models with reactive transport models to predict the fate of contaminants in the subsurface.  

Science Conference Proceedings (OSTI)

This project successfully accomplished its goal of coupling genome-scale metabolic models with hydrological and geochemical models to predict the activity of subsurface microorganisms during uranium bioremediation. Furthermore, it was demonstrated how this modeling approach can be used to develop new strategies to optimize bioremediation. The approach of coupling genome-scale metabolic models with reactive transport modeling is now well enough established that it has been adopted by other DOE investigators studying uranium bioremediation. Furthermore, the basic principles developed during our studies will be applicable to much broader investigations of microbial activities, not only for other types of bioremediation, but microbial metabolism in diversity of environments. This approach has the potential to make an important contribution to predicting the impact of environmental perturbations on the cycling of carbon and other biogeochemical cycles.

Lovley, Derek R.

2012-10-31T23:59:59.000Z

298

Using a scalable modeling and simulation framework to evaluate the benefits of intelligent transportation systems.  

SciTech Connect

A scalable, distributed modeling and simulation framework has been developed at Argonne National Laboratory to study Intelligent Transportation Systems. The framework can run on a single-processor workstation, or run distributed on a multiprocessor computer or network of workstations. The framework is modular and supports plug-in models, hardware, and live data sources. The initial set of models currently includes road network and traffic flow, probe and smart vehicles, traffic management centers, communications between vehicles and centers, in-vehicle navigation systems, roadway traffic advisories. The modeling and simulation capability has been used to examine proposed ITS concepts. Results are presented from modeling scenarios from the Advanced Driver and Vehicle Advisory Navigation Concept (ADVANCE) experimental program to demonstrate how the framework can be used to evaluate the benefits of ITS and to plan future ITS operational tests and deployment initiatives.

Ewing, T.; Tentner, A.

2000-03-21T23:59:59.000Z

299

Predictability of Total Ozone Using a Global Three-Dimensional Chemical Transport Model Coupled with the MRI/JMA98 GCM  

Science Conference Proceedings (OSTI)

A global three-dimensional chemical transport model is being developed for forecasting total ozone. The model includes detailed stratospheric chemistry and transport and couples with a dynamical module of the Meteorological Research Institute/...

T. T. Sekiyama; K. Shibata

2005-08-01T23:59:59.000Z

300

TransCom model simulations of CH? and related species: linking transport, surface flux and chemical loss with CH? variability in the troposphere and lower stratosphere  

E-Print Network (OSTI)

A chemistry-transport model (CTM) intercomparison experiment (TransCom-CH?) has been designed to investigate the roles of surface emissions, transport and chemical loss in simulating the global methane distribution. Model ...

Patra, P. K.

Note: This page contains sample records for the topic "transportation greet model" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

A reaction-based paradigm to model reactive chemical transport in groundwater with general kinetic and equilibrium reactions  

Science Conference Proceedings (OSTI)

This paper presents a reaction-based water quality transport model in subsurface flow systems. Transport of chemical species with a variety of chemical and physical processes is mathematically described by M partial differential equations (PDEs). Decomposition via Gauss-Jordan column reduction of the reaction network transforms M species reactive transport equations into two sets of equations: a set of thermodynamic equilibrium equations representing NE equilibrium reactions and a set of reactive transport equations of M-NE kinetic-variables involving no equilibrium reactions (a kinetic-variable is a linear combination of species). The elimination of equilibrium reactions from reactive transport equations allows robust and efficient numerical integration. The model solves the PDEs of kinetic-variables rather than individual chemical species, which reduces the number of reactive transport equations and simplifies the reaction terms in the equations. A variety of numerical methods are investigated for solving the coupled transport and reaction equations. Simulation comparisons with exact solutions were performed to verify numerical accuracy and assess the effectiveness of various numerical strategies to deal with different application circumstances. Two validation examples involving simulations of uranium transport in soil columns are presented to evaluate the ability of the model to simulate reactive transport with complex reaction networks involving both kinetic and equilibrium reactions.

Zhang, Fan [ORNL; Yeh, Gour-Tsyh [University of Central Florida, Orlando; Parker, Jack C [ORNL; Brooks, Scott C [ORNL; Pace, Molly [ORNL; Kim, Young Jin [ORNL; Jardine, Philip M [ORNL; Watson, David B [ORNL

2007-01-01T23:59:59.000Z

302

A critical view on transport and entanglement in models of photosynthesis  

E-Print Network (OSTI)

We revisit critically the recent claims, inspired by quantum optics and quantum information, that there is entanglement in the biological pigment protein complexes, and that it is responsible for the high transport efficiency. While unexpectedly long coherence times were experimentally demonstrated, the existence of entanglement is, at the moment, a purely theoretical conjecture; it is this conjecture that we analyze. As demonstrated by a toy model, a similar transport phenomenology can be obtained without generating entanglement. Furthermore, we also argue that even if entanglement does exist, it is purely incidental and seems to plays no essential role for the transport efficiency. We emphasize that our paper is not a proof that entanglement does not exist in light-harvesting complexes - this would require a knowledge of the system and its parameters well beyond the state of the art. Rather, we present a counter-example to the recent claims of entanglement, showing that the arguments, as they stand at the moment, are not sufficiently justified and hence cannot be taken as proof for the existence of entanglement, let alone of its essential role, in the excitation transport.

Markus Tiersch; Sandu Popescu; Hans J. Briegel

2011-04-19T23:59:59.000Z

303

Multimodal Transport Modeling for Nairobi, Kenya: Insights and Recommendations with an Evidence-Based Model  

E-Print Network (OSTI)

An approach for Nairobi, Kenya. Working Paper UCB-ITS-VWP-Modeling for Nairobi, Kenya: Insights and RecommendationsModeling for Nairobi, Kenya: Insights and Recommendations

Gonzales, Eric J.; Chavis, Celeste; Li, Yuwei; Daganzo, Carlos F.

2009-01-01T23:59:59.000Z

304

Life Cycle Regulation of Transportation Fuels: Uncertainty and its Policy Implications  

E-Print Network (OSTI)

or as a chemical feedstock. Cellulosic and sugarcane ethanolcellulosic feed- stocks, a GREET parameter declares the fraction of the feedstock

Plevin, Richard Jay

2010-01-01T23:59:59.000Z

305

Satellite data assimilation and estimation of a 3D coastal sediment transport model using error-subspace emulators  

Science Conference Proceedings (OSTI)

This paper describes sequential assimilation of data into a three-dimensional coastal ocean model using fast and cheap statistical surrogates of the model (emulators). The model simulates resuspension and deposition of fine sediments in a macro-tidal ... Keywords: Coastal, Data assimilation, Emulator, Model, Remote sensing, Sediment transport

N. Margvelashvili; J. Andrewartha; M. Herzfeld; B. J. Robson; V. E. Brando

2013-02-01T23:59:59.000Z

306

Exact Solutions of Burnt-Bridge Models for Molecular Motor Transport  

E-Print Network (OSTI)

Transport of molecular motors, stimulated by interactions with specific links between consecutive binding sites (called ``bridges''), is investigated theoretically by analyzing discrete-state stochastic ``burnt-bridge'' models. When an unbiased diffusing particle crosses the bridge, the link can be destroyed (``burned'') with a probability $p$, creating a biased directed motion for the particle. It is shown that for probability of burning $p=1$ the system can be mapped into one-dimensional single-particle hopping model along the periodic infinite lattice that allows one to calculate exactly all dynamic properties. For general case of $pmotor proteins.

Alexander Yu. Morozov; Ekaterina Pronina; Anatoly B. Kolomeisky; Maxim N. Artyomov

2006-10-24T23:59:59.000Z

307

Triangular flow in heavy ion collisions in a multiphase transport model  

E-Print Network (OSTI)

We obtain a new set of parameters in a multiphase transport (AMPT) model that are able to describe both the charged particle multiplicity density and the elliptic flow measured in Au + Au collisions at center-of-mass energy root(S)NN = 200 GeV at the Relativistic Heavy Ion Collider, although they still give somewhat softer transverse momentum spectra. We then use the model to predict the triangular flow due to fluctuations in the initial collision geometry and study its effect relative to those from other harmonic components of anisotropic flows on the dihadron azimuthal correlations in both central and midcentral collisions.

Xu, Jun; Ko, Che Ming.

2011-01-01T23:59:59.000Z

308

Performance Assessment Transport Modeling of Uranium at the Area 5 Radioactive Waste Management Site at the Nevada National Security Site  

SciTech Connect

Following is a brief summary of the assumptions that are pertinent to the radioactive isotope transport in the GoldSim Performance Assessment model of the Area 5 Radioactive Waste Management Site, with special emphasis on the water-phase reactive transport of uranium, which includes depleted uranium products.

NSTec Radioactive Waste

2010-10-12T23:59:59.000Z

309

First-principles quantum transport modeling of thermoelectricity in single-molecule nanojunctions with graphene nanoribbon electrodes  

Science Conference Proceedings (OSTI)

We overview the nonequilibrium Green function combined with density functional theory (NEGF-DFT) approach to modeling of independent electronic and phononic quantum transport in nanoscale thermoelectrics with examples focused on a new class of devices ... Keywords: First-principles quantum transport, Graphene nanoribbons, Molecular electronics, Thermoelectrics

Branislav K. Nikoli?; Kamal K. Saha; Troels Markussen; Kristian S. Thygesen

2012-03-01T23:59:59.000Z

310

Importance of considering intraborehole flow in solute transport modeling under highly dynamic flow conditions  

SciTech Connect

Correct interpretation of tracer test data is critical for understanding transport processes in the subsurface. This task can be greatly complicated by the presence of intraborehole flows in a highly dynamic flow environment. At a new tracer test site (Hanford IFRC) a dynamic flow field created by changes in the stage of the adjacent Columbia River, coupled with a heterogeneous hydraulic conductivity distribution, leads to considerable variations in vertical hydraulic gradients. These variations, in turn, create intraborehole flows in fully-screened (6.5 m) observation wells with frequently alternating upward and downward movement. This phenomenon, in conjunction with a highly permeable aquifer formation and small horizontal hydraulic gradients, makes modeling analysis and model calibration a formidable challenge. Groundwater head data alone were insufficient to define the flow model boundary conditions, and the movement of the tracer was highly sensitive to the dynamics of the flow field. This study shows that model calibration can be significantly improved by explicitly considering (a) dynamic flow model boundary conditions and (b) intraborehole flow. The findings from this study underscore the difficulties in interpreting tracer tests and understanding solute transport under highly dynamic flow conditions.

Ma, Rui; Zheng, Chunmiao; Tonkin, Matthew J.; Zachara, John M.

2011-04-01T23:59:59.000Z

311

Estimating Bacteria Emissions from Inversion of Atmospheric Transport: Sensitivity to Modelled Particle Characteristics  

SciTech Connect

Model-simulated transport of atmospheric trace components can be combined with observed concentrations to obtain estimates of ground-based sources using various inversion techniques. These approaches have been applied in the past primarily to obtain source estimates for long-lived trace gases such as CO2. We consider the application of similar techniques to source estimation for atmospheric aerosols, by using as a case study the estimation of bacteria emissions from different ecosystem regions in the global atmospheric chemistry and climate model ECHAM5/MESSy-Atmospheric Chemistry (EMAC). Simulated particle concentrations in the tropopause region and at high latitudes, as well as transport of particles to tundra and land ice regions are shown to be highly sensitive to scavenging in mixed-phase clouds, which is poorly characterized in most global climate models. This may be a critical uncertainty in correctly simulating the transport of aerosol particles to the Arctic. Source estimation via Monte Carlo Markov Chain is applied to a suite of sensitivity simulations and the global mean emissions are estimated. We present an analysis of the partitioning of uncertainties in the global mean emissions that are attributable to particle size, CCN activity, the ice nucleation scavenging ratios for mixed-phase and cold clouds, and measurement error. Uncertainty due to CCN activity or to a 1 um error in particle size is typically between 10% and 40% of the uncertainty due to data uncertainty, as measured by the 5%-ile to 95%-ile range of the Monte Carlo ensemble. Uncertainty attributable to the ice nucleation scavenging ratio in mized-phase clouds is as high as 10% to 20% of the data uncertainty. Taken together, the four model 20 parameters examined contribute about half as much to the uncertainty in the estimated emissions as do the measurements. This was a surprisingly large contribution from model uncertainty in light of the substantial data uncertainty, which ranges from 81% to 870% for each of ten ecosystems for this case study. The effects of these and other model parameters in contributing to the uncertainties in the transport of atmospheric aerosol particles should be treated explicitly and systematically in both forward and inverse modelling studies.

Burrows, Susannah M.; Rayner, Perter; Butler, T.; Lawrence, M.

2013-06-04T23:59:59.000Z

312

Environmental fate and transport of chemical signatures from buried landmines -- Screening model formulation and initial simulations  

Science Conference Proceedings (OSTI)

The fate and transport of chemical signature molecules that emanate from buried landmines is strongly influenced by physical chemical properties and by environmental conditions of the specific chemical compounds. Published data have been evaluated as the input parameters that are used in the simulation of the fate and transport processes. A one-dimensional model developed for screening agricultural pesticides was modified and used to simulate the appearance of a surface flux above a buried landmine, estimate the subsurface total concentration, and show the phase specific concentrations at the ground surface. The physical chemical properties of TNT cause a majority of the mass released to the soil system to be bound to the solid phase soil particles. The majority of the transport occurs in the liquid phase with diffusion and evaporation driven advection of soil water as the primary mechanisms for the flux to the ground surface. The simulations provided herein should only be used for initial conceptual designs of chemical pre-concentration subsystems or complete detection systems. The physical processes modeled required necessary simplifying assumptions to allow for analytical solutions. Emerging numerical simulation tools will soon be available that should provide more realistic estimates that can be used to predict the success of landmine chemical detection surveys based on knowledge of the chemical and soil properties, and environmental conditions where the mines are buried. Additional measurements of the chemical properties in soils are also needed before a fully predictive approach can be confidently applied.

Phelan, J.M.; Webb, S.W.

1997-06-01T23:59:59.000Z

313

Effects of modeled terms in the Reynolds-stress transport equations  

DOE Green Energy (OSTI)

A discussion of the origins and interpretation of various previously proposed models for the terms in the incompressible Reynolds-stress equation is given. It is hoped that the interpretations will provoke thoughts that will help in the future modeling of Reynolds-stress transport equations. Different forms of the closed Reynolds-stress equation have been solved numerically for the given mean velocity field of the wake flow behind a flat plate at a Reynolds number of 1000. A finite-difference/finite-volume collocation scheme was used to approximate the spatial derivatives, which were implemented in a time-marching scheme. The numerical time integration produced values for the six independent Reynolds-stress components, the turbulent kinetic energy decay rate, and the turbulent length scale for each of the models tried. The results of the different cases were compared and some conclusions were drawn on the effects of the various investigated modeled terms.

Linn, R.R.

1993-12-31T23:59:59.000Z

314

An Integrated Computer Modeling Environment For Regional Land Use, Air Quality, And Transportation Planning  

E-Print Network (OSTI)

The Land Use, Air Quality, and Transportation Integrated Modeling Environment (LATIME) represents an integrated approach to computer modeling and simulation of land use allocation, travel demand, and mobile source emissions for the Albuquerque, New Mexico, area. This environment provides predictive capability combined with a graphical and geographical interface. The graphical interface shows the causal relationships between data and policy scenarios and supports alternative model formulations. Scenarios are launched from within a Geographic Information System (GIS), and data produced by each model component at each time step within a simulation is stored in the GIS. A menudriven query system is utilized to review link-based results and regional and areawide results. These results can also be compared across time or between alternative land use scenarios. Using this environment, policies can be developed and implemented based on comparative analysis, rather than on single-step future pr...

Charles Hanley Renewable; Norman L. Marshall; Charles J. Hanley; Charles J. Hanley

1997-01-01T23:59:59.000Z

315

Water Transport in PEM Fuel Cells: Advanced Modeling, Material Selection, Testing, and Design Optimization  

NLE Websites -- All DOE Office Websites (Extended Search)

in PEM Fuel Cells: in PEM Fuel Cells: Advanced Modeling, Material Selection, Testing, and Design Optimization J. Vernon Cole and Ashok Gidwani CFDRC Prepared for: DOE Hydrogen Fuel Cell Kickoff Meeting February 13, 2007 This presentation does not contain any proprietary or confidential information. Background Water Management Issues Arise From: ƒ Generation of water by cathodic reaction ƒ Membrane humidification requirements ƒ Capillary pressure driven transport through porous MEA and GDL materials ƒ Scaling bipolar plate channel dimensions J.H. Nam and M. Kaviany, Int. J. Heat Mass Transfer, 46, pp. 4595-4611 (2003) Relevant Barriers and Targets ƒ Improved Gas Diffusion Layer, Flow Fields, Membrane Electrode Assemblies Needed to Improve Water Management: * Flooding blocks reactant transport

316

Groundwater Fate and Transport Modeling for Texarkana Wood Preserving Company Superfund Site, Texarkana, Texas  

SciTech Connect

Fate and transport model results are presented for the Texarkana Wood Preserving Company (TWPC)superfund site. The conceptual model assumes two sources of contamination, specifically, the areas around the old and new process areas. Recent data show the presence of non-aqueous phase liquids (NAPL) in the aquifer that are also sources of dissolved contamination in the aquifer. A flow model was constructed and calibrated against measured hydraulic heads at permanent monitoring wells. Good matches were obtained between model simulated heads and most measured heads. An unexplained exception occurs at monitoring well MW-13 down gradient of the site beyond the measured contaminant plume where the model predicts heads that are more than 2 ft. lower than reported field measurements. Adjusting hydraulic parameters in the model could not account for this anomaly and still preserve the head matches at other wells. There is likely a moderate deficiency in the conceptual model or perhaps a data error. Other information such as substantial amounts of infiltrating surface water in the area or a correction in surveyed elevation would improve the flow model. A particle tracking model calculated a travel time from the new process area to the Days Creek discharge location on the order of 40 years. Travel times from the old process area to Days Creek were calculated to be on the order of 80 years. While these calculations are subject to some uncertainty, travel times of decades are indicated.

Arnett, Ronald Chester

1999-08-01T23:59:59.000Z

317

Influence of Wind Stress, Wind Stress Curl, and Bottom Friction on the Transport of a Model Antarctic Circumpolar Current  

Science Conference Proceedings (OSTI)

Eddy-permitting simulations of a wind-driven quasigeostrophic model in an idealized Southern Ocean setting are used to attempt to describe what sets the wind-driven circumpolar transport of the Antarctic Circumpolar Current (ACC). For weak forcing,...

Louis-Philippe Nadeau; David N. Straub

2012-01-01T23:59:59.000Z

318

Modeled Downward Transport of a Passive Tracer over Western North America during an Asian Dust Event in April 1998  

Science Conference Proceedings (OSTI)

An intense Gobi Desert dust storm in April 1998 loaded the midtroposphere with dust that was transported across the Pacific to western North America. The Mesoscale Compressible Community (MC2) model was used to investigate mechanisms causing ...

Joshua P. Hacker; Ian G. McKendry; Roland B. Stull

2001-09-01T23:59:59.000Z

319

Anisotropic Material Transport by Eddies and Eddy-Driven Currents in a Model of the North Atlantic  

Science Conference Proceedings (OSTI)

This study analyzes anisotropic properties of the material transport by eddies and eddy-driven zonal jets in a general circulation model of the North Atlantic through the analysis of Lagrangian particle trajectories. Spreading ratesdefined here ...

Igor Kamenkovich; Pavel Berloff; Joseph Pedlosky

2009-12-01T23:59:59.000Z

320

User-Oriented Two-Dimensional Measure of Effectiveness for the Evaluation of Transport and Dispersion Models  

Science Conference Proceedings (OSTI)

A two-dimensional measure of effectiveness for comparing hazardous material transport and dispersion model predictions and field observations has been developed. This measure is used for comparing predictions and observations paired in space and ...

Steve Warner; Nathan Platt; James F. Heagy

2004-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "transportation greet model" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Influence of Low-Frequency Indonesian Throughflow Transport on Temperatures in the Indian Ocean in a Coupled Model  

Science Conference Proceedings (OSTI)

The relationship between 3- and 10-yr variability in Indian Ocean temperatures and Indonesian throughflow (ITF) volume transport is examined using results from a 300-yr integration of the coupled NCAR Parallel Climate Model (PCM). Correlation and ...

James T. Potemra; Niklas Schneider

2007-04-01T23:59:59.000Z

322

Importance of Using Observations of Mixing Depths in order to Avoid Large Prediction Errors by a Transport and Dispersion Model  

Science Conference Proceedings (OSTI)

The mixing depth of the boundary layer is an input to most atmospheric transport and dispersion (ATD) models, which obtain mixing depths in one of four ways: 1) observations by radiosondes, sodars, or other devices; 2) simulations by regional or ...

J. M. White; J. F. Bowers; S. R. Hanna; J. K. Lundquist

2009-01-01T23:59:59.000Z

323

Prediction of continental shelf sediment transport using a theoretical model of the wave-current boundary layer  

E-Print Network (OSTI)

This thesis presents an application of the Grant-Madsen-Glenn bottom boundary layer model (Grant and Madsen, 1979; Glenn and Grant, 1987) to predictions of sediment transport on the continental shelf. The analysis is a ...

Goud, Margaret R

1987-01-01T23:59:59.000Z

324

A Comparison of Two Types of Atmospheric Transport ModelsUse of Observed Winds Versus Dynamically Predicted Winds  

Science Conference Proceedings (OSTI)

Dynamic and kinematic trajectory Models were used to diagnose long-range transport during a 24-b period of the NEROS (1979) field study. The dynamic model consisted of a three-dimensional primitive equation model which predicted winds on a 25-km ...

Thomas T. Warner; Roderick R. Fizz; Nelson L. Seaman

1983-03-01T23:59:59.000Z

325

Shock of three-state model for intracellular transport of kinesin KIF1A  

E-Print Network (OSTI)

Recently, a three-state model is presented to describe the intracellular traffic of unconventional (single-headed) kinesin KIF1A [Phys. Rev. Lett. {\\bf 95}, 118101 (2005)], in which each motor can bind strongly or weakly to its microtubule track, and each binding site of the track might be empty or occupied by one motor. As the usual two-state model, i.e. the totally asymmetric simple exclusion process (TASEP) with motor detachment and attachment, in steady state of the system, this three-state model also exhibits shock (or domain wall separating the high-density and low density phases) and boundary layers. In this study, using mean-field analysis, the conditions of existence of shock and boundary layers are obtained theoretically. Combined with numerical calculations, the properties of shock are also studied. This study will be helpful to understand the biophysical properties of the collective transport of kinesin KIF1A.

Yunxin Zhang

2011-05-16T23:59:59.000Z

326

Angular momentum transport modeling: achievements of a gyrokinetic quasi-linear approach  

E-Print Network (OSTI)

QuaLiKiz, a model based on a local gyrokinetic eigenvalue solver is expanded to include momentum flux modeling in addition to heat and particle fluxes. Essential for accurate momentum flux predictions, the parallel asymmetrization of the eigenfunctions is successfully recovered by an analytical fluid model. This is tested against self-consistent gyrokinetic calculations and allows for a correct prediction of the ExB shear impact on the saturated potential amplitude by means of a mixing length rule. Hence, the effect of the ExB shear is recovered on all the transport channels including the induced residual stress. Including these additions, QuaLiKiz remains ~10 000 faster than non-linear gyrokinetic codes allowing for comparisons with experiments without resorting to high performance computing. The example is given of momentum pinch calculations in NBI modulation experiments.

Cottier, P; Camenen, Y; Gurcan, O D; Casson, F J; Garbet, X; Hennequin, P; Tala, T

2014-01-01T23:59:59.000Z

327

Using toughreact to model reactive fluid flow and geochemical transport in hydrothermal systems  

E-Print Network (OSTI)

multiphase flow, solute transport and reactive chemistry in porousmultiphase fluid flow, mass transport and chemical reactions, (2) reactive fluid flow and transport in fractured rocks as well as porous

Xu, Tianfu; Sonnenthal, Eric; Spycher, Nicolas; Pruess, Karsten

2003-01-01T23:59:59.000Z

328

Modeling heat conduction and radiation transport with the diffusion equation in  

NLE Websites -- All DOE Office Websites (Extended Search)

heat conduction and radiation transport with the diffusion equation in NIF ALE-AMR heat conduction and radiation transport with the diffusion equation in NIF ALE-AMR This article has been downloaded from IOPscience. Please scroll down to see the full text article. 2010 J. Phys.: Conf. Ser. 244 022075 (http://iopscience.iop.org/1742-6596/244/2/022075) Download details: IP Address: 50.136.219.251 The article was downloaded on 18/04/2013 at 01:36 Please note that terms and conditions apply. View the table of contents for this issue, or go to the journal homepage for more Home Search Collections Journals About Contact us My IOPscience Modeling Heat Conduction and Radiation Transport with the Diffusion Equation in NIF ALE-AMR A.C. Fisher 1 , D.S. Bailey 1 , T.B. Kaiser 1 , B.T.N. Gunney 1 , N.D. Masters 1 , A.E. Koniges 2 , D.C. Eder 1 , R.W. Anderson 1 1: Lawrence Livermore National Laboratory,

329

Multiphase Modeling of Flow, Transport, and Biodegradation in a Mesoscale Landfill Bioreactor  

DOE Green Energy (OSTI)

The need to control gas and leachate production and minimize refuse volume in municipal solid waste landfills has motivated the development of landfill simulation models to predict and design optimal treatment processes. We have developed a multiphase and multicomponent nonisothermal module called T2LBM for the three-dimensional TOUGH2 flow and transport simulator. T2LBM can be used to simulate aerobic or anaerobic biodegradation of municipal solid waste and the associated flow and transport of gas and liquid through the refuse mass. Acetic acid is used as a proxy for all biodegradable substrates in the refuse. T2LBM incorporates a Monod kinetic rate law for the biodegradation of acetic acid by either aerobic or anaerobic microbes as controlled by the local oxygen concentration. We have verified the model against published data, and applied it to our own mesoscale laboratory aerobic landfill bioreactor experiments. We observe spatial variability of flow and biodegradation consistent with permeability heterogeneity and the geometry of the radial grid. The model is capable of matching results of a shut-in test where the respiration of the system is measured over time.

Oldenburg, Curtis M.; Borglin, Sharon E.; Hazen, Terry C.

2002-02-01T23:59:59.000Z

330

Overview of research and development in subsurface fate and transport modeling  

Science Conference Proceedings (OSTI)

The US Department of Energy is responsible for the remediation of over 450 different subsurface-contaminated sites. Contaminant plumes at these sites range in volume from several to millions of cubic yards. The concentration of contaminants also ranges over several orders of magnitude. Contaminants include hazardous wastes such as heavy metals and organic chemicals, radioactive waste including tritium, uranium, and thorium, and mixed waste, which is a combination of hazardous and radioactive wastes. The physical form of the contaminants includes solutes, nonaqueous phase liquids (NAPLs), and vapor phase contaminants such as volatilized organic chemicals and radon. The subject of contaminant fate and transport modeling is multi-disciplinary, involving hydrology, geology, microbiology, chemistry, applied mathematics, computer science, and other areas of expertise. It is an issue of great significance in the United States and around the world. As such, many organizations have substantial programs in this area. In gathering data to prepare this report, a survey was performed of research and development work that is funded by US government agencies to improve the understanding and mechanistic modeling of processes that control contaminant movement through subsurface systems. Government agencies which fund programs that contain fate and transport modeling components include the Environmental Protection Agency, Nuclear Regulatory Commission, Department of Agriculture, Department of Energy, National Science Foundation, Department of Defense, United States Geological Survey, and National Institutes of Health.

Sullivan, T.M. [Brookhaven National Lab., Upton, NY (United States); Chehata, M. [Science Applications Internationa Corp. (United States)

1995-05-01T23:59:59.000Z

331

Geophysical monitoring and reactive transport modeling of ureolytically-driven calcium carbonate precipitation  

SciTech Connect

Ureolytically-driven calcium carbonate precipitation is the basis for a promising in-situ remediation method for sequestration of divalent radionuclide and trace metal ions. It has also been proposed for use in geotechnical engineering for soil strengthening applications. Monitoring the occurrence, spatial distribution, and temporal evolution of calcium carbonate precipitation in the subsurface is critical for evaluating the performance of this technology and for developing the predictive models needed for engineering application. In this study, we conducted laboratory column experiments using natural sediment and groundwater to evaluate the utility of geophysical (complex resistivity and seismic) sensing methods, dynamic synchrotron x-ray computed tomography (micro-CT), and reactive transport modeling for tracking ureolytically-driven calcium carbonate precipitation processes under site relevant conditions. Reactive transport modeling with TOUGHREACT successfully simulated the changes of the major chemical components during urea hydrolysis. Even at the relatively low level of urea hydrolysis observed in the experiments, the simulations predicted an enhanced calcium carbonate precipitation rate that was 3-4 times greater than the baseline level. Reactive transport modeling results, geophysical monitoring data and micro-CT imaging correlated well with reaction processes validated by geochemical data. In particular, increases in ionic strength of the pore fluid during urea hydrolysis predicted by geochemical modeling were successfully captured by electrical conductivity measurements and confirmed by geochemical data. The low level of urea hydrolysis and calcium carbonate precipitation suggested by the model and geochemical data was corroborated by minor changes in seismic P-wave velocity measurements and micro-CT imaging; the latter provided direct evidence of sparsely distributed calcium carbonate precipitation. Ion exchange processes promoted through NH{sub 4}{sup +} production during urea hydrolysis were incorporated in the model and captured critical changes in the major metal species. The electrical phase increases were potentially due to ion exchange processes that modified charge structure at mineral/water interfaces. Our study revealed the potential of geophysical monitoring for geochemical changes during urea hydrolysis and the advantages of combining multiple approaches to understand complex biogeochemical processes in the subsurface.

Wu, Y.; Ajo-Franklin, J.B.; Spycher, N.; Hubbard, S.S.; Zhang, G.; Williams, K.H.; Taylor, J.; Fujita, Y.; Smith, R.

2011-07-15T23:59:59.000Z

332

Geophysical Monitoring and Reactive Transport Modeling of Ureolytically-Driven Calcium Carbonate Precipitation  

Science Conference Proceedings (OSTI)

Ureolytically-driven calcium carbonate precipitation is the basis for a promising in-situ remediation method for sequestration of divalent radionuclide and trace metal ions. It has also been proposed for use in geotechnical engineering for soil strengthening applications. Monitoring the occurrence, spatial distribution, and temporal evolution of calcium carbonate precipitation in the subsurface is critical for evaluating the performance of this technology and for developing the predictive models needed for engineering application. In this study, we conducted laboratory column experiments using natural sediment and groundwater to evaluate the utility of geophysical (complex resistivity and seismic) sensing methods, dynamic synchrotron x-ray computed tomography (micro-CT), and reactive transport modeling for tracking ureolytically-driven calcium carbonate precipitation processes under site relevant conditions. Reactive transport modeling with TOUGHREACT successfully simulated the changes of the major chemical components during urea hydrolysis. Even at the relatively low level of urea hydrolysis observed in the experiments, the simulations predicted an enhanced calcium carbonate precipitation rate that was 3-4 times greater than the baseline level. Reactive transport modeling results, geophysical monitoring data and micro-CT imaging correlated well with reaction processes validated by geochemical data. In particular, increases in ionic strength of the pore fluid during urea hydrolysis predicted by geochemical modeling were successfully captured by electrical conductivity measurements and confirmed by geochemical data. The low level of urea hydrolysis and calcium carbonate precipitation suggested by the model and geochemical data was corroborated by minor changes in seismic P-wave velocity measurements and micro-CT imaging; the latter provided direct evidence of sparsely distributed calcium carbonate precipitation. Ion exchange processes promoted through NH4+ production during urea hydrolysis were incorporated in the model and captured critical changes in the major metal species. The electrical phase increases were potentially due to ion exchange processes that modified charge structure at mineral/water interfaces. Our study revealed the potential of geophysical monitoring for geochemical changes during urea hydrolysis and the advantages of combining multiple approaches to understand complex biogeochemical processes in the subsurface.

Yuxin Wu; Jonathan B. Ajo-Franklin; Nicolas Spycher; Susan S. Hubbard; Guoxiang Zhang; Kenneth H. Williams; Joanna Taylor; Yoshiko Fujita; Robert Smith

2011-09-01T23:59:59.000Z

333

Mesoscopic modeling of multi-physicochemical transport phenomena in porous media  

SciTech Connect

We present our recent progress on mesoscopic modeling of multi-physicochemical transport phenomena in porous media based on the lattice Boltzmann method. Simulation examples include injection of CO{sub 2} saturated brine into a limestone rock, two-phase behavior and flooding phenomena in polymer electrolyte fuel cells, and electroosmosis in homogeneously charged porous media. It is shown that the lattice Boltzmann method can account for multiple, coupled physicochemical processes in these systems and can shed some light on the underlying physics occuning at the fundamental scale. Therefore, it can be a potential powerful numerical tool to analyze multi-physicochemical processes in various energy, earth, and environmental systems.

Kang, Qinjin [Los Alamos National Laboratory; Wang, Moran [Los Alamos National Laboratory; Mukherjee, Partha P [Los Alamos National Laboratory; Lichtner, Peter C [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

334

Constructing Soliton and Kink Solutions of PDE Models in Transport and Biology  

E-Print Network (OSTI)

We present a review of our recent works directed towards discovery of a periodic, kink-like and soliton-like travelling wave solutions within the models of transport phenomena and the mathematical biology. Analytical description of these wave patterns is carried out by means of our modification of the direct algebraic balance method. In the case when the analytical description fails, we propose to approximate invariant travelling wave solutions by means of an infinite series of exponential functions. The effectiveness of the method of approximation is demonstrated on a hyperbolic modification of Burgers equation.

Vsevolod A. Vladimirov; Ekaterina V. Kutafina; Anna Pudelko

2006-06-19T23:59:59.000Z

335

Coupled modeling of groundwater flow solute transport, chemical reactions and microbial processes in the 'SP' island  

Science Conference Proceedings (OSTI)

The Redox Zone Experiment was carried out at the Aespoe HRL in order to study the redox behavior and the hydrochemistry of an isolated vertical fracture zone disturbed by the excavation of an access tunnel. Overall results and interpretation of the Redox Zone Project were reported by /Banwart et al, 1995/. Later, /Banwart et al, 1999/ presented a summary of the hydrochemistry of the Redox Zone Experiment. Coupled groundwater flow and reactive transport models of this experiment were carried out by /Molinero, 2000/ who proposed a revised conceptual model for the hydrogeology of the Redox Zone Experiment which could explain simultaneously measured drawdown and salinity data. The numerical model was found useful to understand the natural system. Several conclusions were drawn about the redox conditions of recharge waters, cation exchange capacity of the fracture zone and the role of mineral phases such as pyrite, calcite, hematite and goethite. This model could reproduce the measured trends of dissolved species, except for bicarbonate and sulfate which are affected by microbially-mediated processes. In order to explore the role of microbial processes, a coupled numerical model has been constructed which accounts for water flow, reactive transport and microbial processes. The results of this model is presented in this report. This model accounts for groundwater flow and reactive transport in a manner similar to that of /Molinero, 2000/ and extends the preliminary microbial model of /Zhang, 2001/ by accounting for microbially-driven organic matter fermentation and organic matter oxidation. This updated microbial model considers simultaneously the fermentation of particulate organic matter by yeast and the oxidation of dissolved organic matter, a product of fermentation. Dissolved organic matter is produced by yeast and serves also as a substrate for iron-reducing bacteria. Model results reproduce the observed increase in bicarbonate and sulfate concentration, thus adding additional evidence for the possibility of organic matter oxidation as the main source of bicarbonate. Model results indicate that pH and Eh are relatively stable. The dissolution-precipitation trends of hematite, pyrite and calcite also coincide with those indicated by the conceptual model. A thorough sensitivity analysis has been performed for the most relevant microbial parameters as well as for initial and boundary POC and DOC concentrations. The results of such analysis indicate that computed concentrations of bicarbonate, sulfate and DOC are sensitive to most of the microbial parameters, including specific growth rates, half-saturation constants, proportionality coefficients and yield coefficients. Model results, however, are less sensitive to the yield coefficient of DOC to iron-reducer bacteria. The sensitivity analysis indicates that changes in fermentation microbial parameters affect the growth of the iron-reducer, thus confirming the interconnection of both microbial processes. Computed concentrations of bicarbonate and sulfate are found to be sensitive to changes in the initial concentration of POC and the boundary concentration of DOC, but they lack sensitivity to the initial concentration of DOC and the boundary concentration of POC. The explanation for such result is related to the fact that POC has a low mobility due to its large molecular weight. DOC, however, can migrate downwards. Although a coupled hydro-bio-geochemical 1-D model can reproduce the observed ''unexpected'' increase of concentrations of bicarbonate and sulfate at a depth of 70 m, further modeling work is required in order to obtain a similar conclusion under the more realistic two dimensional conditions of the fracture zone.

Samper, Javier; Molinero, Jorg; Changbing, Yang; Zhang, Guoxiang

2003-12-01T23:59:59.000Z

336

A triple-continuum approach for modeling flow and transport processes in fractured rock  

E-Print Network (OSTI)

Multiphase Tracer Transport in Heterogeneous Fractured Porousmultiphase, nonisothermal flow and solute transport in fractured porousmultiphase fluid flow, heat transfer, and chemical migration in a fractured porous

Wu, Yu-Shu; Liu, H.H.; Bodvarsson, G.S; Zellmer, K .E.

2001-01-01T23:59:59.000Z

337

Urban airshed modeling of air quality impacts of alternative transportation fuel use in Los Angeles and Atlanta  

DOE Green Energy (OSTI)

The main objective of NREL in supporting this study is to determine the relative air quality impact of the use of compressed natural gas (CNG) as an alternative transportation fuel when compared to low Reid vapor pressure (RVP) gasoline and reformulated gasoline (RFG). A table lists the criteria, air toxic, and greenhouse gas pollutants for which emissions were estimated for the alternative fuel scenarios. Air quality impacts were then estimated by performing photochemical modeling of the alternative fuel scenarios using the Urban Airshed Model Version 6.21 and the Carbon Bond Mechanism Version IV (CBM-IV) (Geary et al., 1988) Using this model, the authors examined the formation and transport of ozone under alternative fuel strategies for motor vehicle transportation sources for the year 2007. Photochemical modeling was performed for modeling domains in Los Angeles, California, and Atlanta, Georgia.

NONE

1997-12-01T23:59:59.000Z

338

Reactive transport modelling of the interaction of fission product ground contamination with alkaline and cementitious leachates  

Science Conference Proceedings (OSTI)

The fission products Cs-137 and Sr-90 are amongst the most common radionuclides occurring in ground contamination at the UK civil nuclear sites. Such contamination is often associated with alkaline liquids and the mobility of these fission products may be affected by these chemical conditions. Similar geochemical effects may also result from cementitious leachate associated with building foundations and the use of grouts to remediate ground contamination. The behaviour of fission products in these scenarios is a complex interaction of hydrogeological and geochemical processes. A suite of modelling tools have been developed to investigate the behaviour of a radioactive plume containing Cs and Sr. Firstly the effects of sorption due to cementitious groundwater is modelled using PHREEQC. This chemical model is then incorporated into PHAST for the 3-D reactive solute transport modeling. Results are presented for a generic scenario including features and processes that are likely to be relevant to a number of civil UK nuclear sites. Initial results show that modelling can be a very cost-effective means to study the complex hydrogeological and geochemical processes involved. Modelling can help predict the mobility of contaminants in a range of site end point scenarios, and in assessing the consequences of decommissioning activities. (authors)

Kwong, S.; Small, J. [Nexia Solutions Ltd, The British Technology Centre, Sellafield, Seascale, CA20 1PG (United Kingdom)

2007-07-01T23:59:59.000Z

339

THREE-DIMENSIONAL MAGNETOHYDRODYNAMIC MODELING OF THE SOLAR WIND INCLUDING PICKUP PROTONS AND TURBULENCE TRANSPORT  

Science Conference Proceedings (OSTI)

To study the effects of interstellar pickup protons and turbulence on the structure and dynamics of the solar wind, we have developed a fully three-dimensional magnetohydrodynamic solar wind model that treats interstellar pickup protons as a separate fluid and incorporates the transport of turbulence and turbulent heating. The governing system of equations combines the mean-field equations for the solar wind plasma, magnetic field, and pickup protons and the turbulence transport equations for the turbulent energy, normalized cross-helicity, and correlation length. The model equations account for photoionization of interstellar hydrogen atoms and their charge exchange with solar wind protons, energy transfer from pickup protons to solar wind protons, and plasma heating by turbulent dissipation. Separate mass and energy equations are used for the solar wind and pickup protons, though a single momentum equation is employed under the assumption that the pickup protons are comoving with the solar wind protons. We compute the global structure of the solar wind plasma, magnetic field, and turbulence in the region from 0.3 to 100 AU for a source magnetic dipole on the Sun tilted by 0 Degree-Sign -90 Degree-Sign and compare our results with Voyager 2 observations. The results computed with and without pickup protons are superposed to evaluate quantitatively the deceleration and heating effects of pickup protons, the overall compression of the magnetic field in the outer heliosphere caused by deceleration, and the weakening of corotating interaction regions by the thermal pressure of pickup protons.

Usmanov, Arcadi V.; Matthaeus, William H. [Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States); Goldstein, Melvyn L., E-mail: arcadi.usmanov@nasa.gov [Code 673, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

2012-07-20T23:59:59.000Z

340

A Complete Transport Validated Model on a Zeolite Membrane for Carbon Dioxide Permeance and Capture  

E-Print Network (OSTI)

The CO2 emissions from major industries cause serious global environment problems and their mitigation is urgently needed. The use of zeolite membranes is a very efficient way in order to capture CO2 from some flue gases. The dominant transport mechanism at low temperature andor high pressure is the diffusion through the membrane. This procedure can be divided in three steps: Adsorption of the molecules of the species in the surface of the membrane, then a driving force gives a path where the species follow inside the membrane and finally the species desorbed from the surface of the membrane. The current work is aimed at developing a simulation model for the CO2 transport through a zeolite membrane and estimate the diffusion phenomenon through a very thin membrane of 150 nm in a Wicke-Kallenbach cell. The cell is cylindrical in shape with diameter of 19 mm and consists of a retentate gas chamber, a permeate gas chamber which are separated by a cylindrical zeolite membrane. This apparatus have been modeled wit...

Gkanas, Evangelos I; Stubos, Athanasios K; Makridis, Sofoklis S

2013-01-01T23:59:59.000Z

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341

Modeling Studies on the Transport of Benzene and H2S in CO2-Water Systems  

Science Conference Proceedings (OSTI)

In this study, reactive transport simulations were used to assess the mobilization and transport of organics with supercritical CO{sub 2} (SCC), and the co-injection and transport of H{sub 2}S with SCC. These processes were evaluated at conditions of typical storage reservoirs, and for cases of hypothetical leakage from a reservoir to an overlying shallower fresh water aquifer. Modeling capabilities were developed to allow the simulation of multiphase flow and transport of H{sub 2}O, CO{sub 2}, H{sub 2}S, as well as specific organic compounds (benzene), coupled with multicomponent geochemical reaction and transport. This included the development of a new simulator, TMVOC-REACT, starting from existing modules of the TOUGH2 family of codes. This work also included an extensive literature review, calculation, and testing of phase-partitioning properties for mixtures of the phases considered. The reactive transport simulations presented in this report are primarily intended to illustrate the capabilities of the new simulator. They are also intended to help evaluate and understand various processes at play, in a more qualitative than quantitative manner, and only for hypothetical scenarios. Therefore, model results are not intended as realistic assessments of groundwater quality changes for specific locations, and they certainly do not provide an exhaustive evaluation of all possible site conditions, especially given the large variability and uncertainty in hydrogeologic and geochemical parameter input into simulations. The first step in evaluating the potential mobilization and transport of organics was the identification of compounds likely to be present in deep storage formations, and likely to negatively impact freshwater aquifers if mobilized by SCC. On the basis of a literature review related to the occurrence of these organic compounds, their solubility in water and SCC, and their toxicity (as reflected by their maximum contaminant levels MCL), benzene was selected as a key compound for inclusion into numerical simulations. Note that considering additional organic compounds and/or mixtures of such compounds in the simulations was beyond the scope of this study, because of the effort required to research, calculate, and validate the phase-partitioning data necessary for simulations. The injection of CO{sub 2} into a deep saline aquifer was simulated, followed by modeling the leaching of benzene by SCC and transport of benzene to an overlying aquifer along a hypothetical leakage pathway. One- and two-dimensional models were set up for this purpose. The target storage formation was assumed to initially contain about 10{sup -4} ppm benzene. Model results indicate that: (1) SCC efficiently extracts benzene from the storage formation. (2) Assuming equilibrium, the content of benzene in SCC is roportional to the concentration of benzene in the aqueous and solid phases. (3) Benzene may co-migrate with CO{sub 2} into overlying aquifers if a leakage pathway is present. Because the aqueous solubility of benzene in contact with CO{sub 2} is lower than the aqueous solubility of CO{sub 2}, benzene is actually enriched in the CO{sub 2} phase as the plume advances. (4) For the case studied here, the resulting aqueous benzene concentration in the overlying aquifer is on the same order of magnitude as the initial concentration in the storage formation. This generic modeling study illustrates, in a semi-quantitative manner, the possible mobilization of benzene by SCC. The extent to which the mobilization of this organic compound evolves temporally and spatially depends on a large number of controlling parameters and is largely site specific. Therefore, for more 'truly' predictive work, further sensitivity studies should be conducted, and further modeling should be integrated with site-specific laboratory and/or field experimental data. The co-injection of H{sub 2}S with CO{sub 2} into a deep saline aquifer was also simulated. In addition, the model considered leakage of the supercritical CO{sub 2}+H{sub 2}S mixture along a preferential p

Zheng, L.; Spycher, N.; Xu, T.; Apps, J.; Kharaka, Y.; Birkholzer, J.T.

2010-11-05T23:59:59.000Z

342

DEGAS 2 Neutral Transport Modeling of High Density, Low Temperature Plasmas  

E-Print Network (OSTI)

Neutral transport in the high density, low temperature plasma regime is examined using the degas 2 Monte Carlo neutral transport code. Degas 2 is shown to agree with an analytic fluid neutral model valid in this regime as long as the grid cell spacing is less than twice the neutral mean-free path. Using new atomic physics data provided by the collisional radiative code cramd, degas 2 is applied to a detached Alcator C-Mod discharge. A model plasma with electron temperature # 1 eV along detached flux tubes, between the target and the ionization front, is used to demonstrate that recombination is essential to matching the experimental data. With the cramd data, # 20% of the total recombination is due to molecular activated recombination. # Massachusetts Institute of Technology , Plasma Fusion Center, 167 Albany Street, Cambridge, MA 02139, USA + Also at I. V. Kurchatov Institute of Atomic Energy 1 Kurchatov Sq., Moscow 123098, Russia # Presently at McKinsey & Company, Inc., London...

D. P. Stotler; A. Yu. Pigarov; C. F. F. Karney; S. I. Krasheninnikov; B. LaBombard; B. Lipschultz; G. M. McCracken; A. Niemczewski; J. A. Snipes; J. L. Terry; R. A. Vesey

1997-01-01T23:59:59.000Z

343

Analysing the impact of disruptions in intermodal transport networks: A micro simulation-based model  

Science Conference Proceedings (OSTI)

Transport networks have to provide carriers with time-efficient alternative routes in case of disruptions. It is, therefore, essential for transport network planners and operators to identify sections within the network which, if broken, have a considerable ... Keywords: Intermodal transport network, Network vulnerability, Supply chain disruption, Traffic micro simulation, Transport network analysis

Wolfgang Burgholzer; Gerhard Bauer; Martin Posset; Werner Jammernegg

2013-03-01T23:59:59.000Z

344

Final report on LDRD project: A phenomenological model for multicomponent transport with simultaneous electrochemical reactions in concentrated solutions  

DOE Green Energy (OSTI)

A phenomenological model was developed for multicomponent transport of charged species with simultaneous electrochemical reactions in concentrated solutions, and was applied to model processes in a thermal battery cell. A new general framework was formulated and implemented in GOMA (a multidimensional, multiphysics, finite-element computer code developed and being enhanced at Sandia) for modeling multidimensional, multicomponent transport of neutral and charged species in concentrated solutions. The new framework utilizes the Stefan-Maxwell equations that describe multicomponent diffusion of interacting species using composition-insensitive binary diffusion coefficients. The new GOMA capability for modeling multicomponent transport of neutral species was verified and validated using the model problem of ternary gaseous diffusion in a Stefan tube. The new GOMA-based thermal battery computer model was verified using an idealized battery cell in which concentration gradients are absent; the full model was verified by comparing with that of Bernardi and Newman (1987) and validated using limited thermal battery discharge-performance data from the open literature (Dunning 1981) and from Sandia (Guidotti 1996). Moreover, a new Liquid Chemkin Software Package was developed, which allows the user to handle manly aspects of liquid-phase kinetics, thermodynamics, and transport (particularly in terms of computing properties). Lastly, a Lattice-Boltzmann-based capability was developed for modeling pore- or micro-scale phenomena involving convection, diffusion, and simplified chemistry; this capability was demonstrated by modeling phenomena in the cathode region of a thermal battery cell.

CHEN,KEN S.; EVANS,GREGORY H.; LARSON,RICHARD S.; NOBLE,DAVID R.; HOUF,WILLIAM G.

2000-01-01T23:59:59.000Z

345

Transportation Sector Model of the National Energy Modeling System. Volume 2 -- Appendices: Part 3  

SciTech Connect

This Appendix consists of two unpublished reports produced by Energy and Environmental Analysis, Inc., under contract to Oak Ridge National Laboratory. These two reports formed the basis for the subsequent development of the Fuel Economy Model described in Volume 1. They are included in order to document more completely the efforts undertaken to construct a comprehensive model of automobile fuel economy. The supplemental reports are as follows: Supplement 1--Documentation Attributes of Technologies to Improve Automotive Fuel Economy; Supplement 2--Analysis of the Fuel Economy Boundary for 2010 and Comparison to Prototypes.

NONE

1998-01-01T23:59:59.000Z

346

Assessment of Mercury Emissions, Transport, Fate, and Cycling for the Continental United States: Model Structure and Evaluation  

Science Conference Proceedings (OSTI)

New findings on mercury emissions, cycling, and fate have allowed the development of improved simulation tools and the assembly of verification data sets for modeling mercury transport and deposition. This report describes new simulations of mercury emissions, transport, and deposition from the atmosphere that form an important first step in for relating mercury concentrations and deposition rates at particular geographic locations to their ultimate source regions.

2000-12-15T23:59:59.000Z

347

ACCELERATION OF LOW-ENERGY IONS AT PARALLEL SHOCKS WITH A FOCUSED TRANSPORT MODEL  

SciTech Connect

We present a test particle simulation on the injection and acceleration of low-energy suprathermal particles by parallel shocks with a focused transport model. The focused transport equation contains all necessary physics of shock acceleration, but avoids the limitation of diffusive shock acceleration (DSA) that requires a small pitch angle anisotropy. This simulation verifies that the particles with speeds of a fraction of to a few times the shock speed can indeed be directly injected and accelerated into the DSA regime by parallel shocks. At higher energies starting from a few times the shock speed, the energy spectrum of accelerated particles is a power law with the same spectral index as the solution of standard DSA theory, although the particles are highly anisotropic in the upstream region. The intensity, however, is different from that predicted by DSA theory, indicating a different level of injection efficiency. It is found that the shock strength, the injection speed, and the intensity of an electric cross-shock potential (CSP) jump can affect the injection efficiency of the low-energy particles. A stronger shock has a higher injection efficiency. In addition, if the speed of injected particles is above a few times the shock speed, the produced power-law spectrum is consistent with the prediction of standard DSA theory in both its intensity and spectrum index with an injection efficiency of 1. CSP can increase the injection efficiency through direct particle reflection back upstream, but it has little effect on the energetic particle acceleration once the speed of injected particles is beyond a few times the shock speed. This test particle simulation proves that the focused transport theory is an extension of DSA theory with the capability of predicting the efficiency of particle injection.

Zuo, Pingbing; Zhang, Ming; Rassoul, Hamid K. [Department of Physics and Space Sciences, Florida Institute of Technology, Melbourne, FL 32901 (United States)] [Department of Physics and Space Sciences, Florida Institute of Technology, Melbourne, FL 32901 (United States)

2013-04-10T23:59:59.000Z

348

The Relation of Seafloor Voltages to Ocean Transports in North Atlantic Circulation Models: Model Results and Practical Considerations for Transport Monitoring  

Science Conference Proceedings (OSTI)

Motionally induced voltage differences offer one of the few observational methods sensitive to changes in large-scale ocean transports. They present a useful contrast to most oceanographic data by virtue of their natural spatial integration, ...

H. Flosadttir; J. C. Larsen; J. T. Smith

1997-08-01T23:59:59.000Z

349

Correcting transport errors during advection of aerosol and cloud moment sequences in eulerian models  

SciTech Connect

Moment methods are finding increasing usage for simulations of particle population balance in box models and in more complex flows including two-phase flows. These highly efficient methods have nevertheless had little impact to date for multi-moment representation of aerosols and clouds in atmospheric models. There are evidently two reasons for this: First, atmospheric models, especially if the goal is to simulate climate, tend to be extremely complex and take many man-years to develop. Thus there is considerable inertia to the implementation of novel approaches. Second, and more fundamental, the nonlinear transport algorithms designed to reduce numerical diffusion during advection of various species (tracers) from cell to cell, in the typically coarse grid arrays of these models, can and occasionally do fail to preserve correlations between the moments. Other correlated tracers such as isotopic abundances, composition of aerosol mixtures, hydrometeor phase, etc., are subject to this same fate. In the case of moments, this loss of correlation can and occasionally does give rise to unphysical moment sets. When this happens the simulation can come to a halt. Following a brief description and review of moment methods, the goal of this paper is to present two new approaches that both test moment sequences for validity and correct them when they fail. The new approaches work on individual grid cells without requiring stored information from previous time-steps or neighboring cells.

McGraw R.

2012-03-01T23:59:59.000Z

350

Tritium transport in the NuMI decay pipe region - modeling and comparison with experimental data  

DOE Green Energy (OSTI)

The NuMI (Neutrinos at Main Injector) beam facility at Fermilab is designed to produce an intense beam of muon neutrinos to be sent to the MINOS underground experiment in Soudan, Minnesota. Neutrinos are created by the decay of heavier particles. In the case of NuMI, the decaying particles are created by interaction of high-energy protons in a target, creating mostly positive pions. These particles can also interact with their environment, resulting in production of a variety of short-lived radionuclides and tritium. In the NuMI beam, neutrinos are produced by 120 GeV protons from the Fermilab Main Injector accelerator which are injected into the NuMI beam line using single turn extraction. The beam line has been designed for 400 kW beam power, roughly a factor of 2 above the initial (2005-06) running conditions. Extracted protons are bent downwards at a 57mr angle towards the Soudan Laboratory. The meson production target is a 94 cm segmented graphite rod, cooled by water in stainless tubes on the top and bottom of the target. The target is followed by two magnetic horns which are pulsed to 200 kA in synchronization with the passage of the beam, producing focusing of the secondary hadron beam and its daughter neutrinos. Downstream of the second horn the meson beam is transported for 675 m in an evacuated 2 m diameter beam (''decay'') pipe. Subsequently, the residual mesons and protons are absorbed in a water cooled aluminum/steel absorber immediately downstream of the decay pipe. Some 200 m of rock further downstream ranges out all of the residual muons. During beam operations, after installation of the chiller condensate system in December 2005, the concentration of tritiated water in the MINOS sump flow of 177 gpm was around 12 pCi/ml, for a total of 0.010 pCi/day. A simple model of tritium transport and deposition via humidity has been constructed to aid in understanding how tritium reaches the sump water. The model deals with tritium transported as HTO, water in which one hydrogen atom has been replaced with tritium. Based on concepts supported by the modeling, a dehumidification system was installed during May 2006 that reduced the tritium level in the sump by a factor of two. This note is primarily concerned with tritium that was produced in the NuMI target pile, carried by air flow into the target hall and down the decay pipe passageway (where most of it was deposited). The air is exhausted through the existing air vent shaft EAV2 (Figure 1).

Hylen, J.; Plunkett, R.; /Fermilab

2007-03-01T23:59:59.000Z

351

Numerical modeling of species transport in turbulent flow and experimental study on aerosol sampling  

E-Print Network (OSTI)

Numerical simulations were performed to study the turbulent mixing of a scalar species in straight tube, single and double elbow flow configurations. Different Reynolds Averaged Navier Stokes (RANS) and Large Eddy Simulation (LES) models were used to model the turbulence in the flow. Conventional and dynamic Smagorinsky sub-grid scale models were used for the LES simulations. Wall functions were used to resolve the near wall boundary layer. These simulations were run with both two-dimensional and three-dimensional geometries. The velocity and tracer gas concentration Coefficient of Variations were compared with experimental results. The results from the LES simulations compared better with experimental results than the results from the RANS simulations. The level of mixing downstream of a S-shaped double elbow was higher than either the single elbow or the U-shaped double elbow due to the presence of counter rotating vortices. Penetration of neutralized and non-neutralized aerosol particles through three different types of tubing was studied. The tubing used included standard PVC pipes, aluminum conduit and flexible vacuum hose. Penetration through the aluminum conduit was unaffected by the presence or absence of charge neutralization, whereas particle penetrations through the PVC pipe and the flexible hosing were affected by the amount of particle charge. The electric field in a space enclosed by a solid conductor is zero. Therefore charged particles within the conducting aluminum conduit do not experience any force due to ambient electric fields, whereas the charged particles within the non-conducting PVC pipe and flexible hose experience forces due to the ambient electric fields. This increases the deposition of charged particles compared to neutralized particles within the 1.5� PVC tube and 1.5� flexible hose. Deposition 2001a (McFarland et al. 2001) software was used to predict the penetration through transport lines. The prediction from the software compared well with experiments for all cases except when charged particles were transported through non-conducting materials. A Stairmand cyclone was designed for filtering out large particles at the entrance of the transport section.

Vijayaraghavan, Vishnu Karthik

2006-12-01T23:59:59.000Z

352

A coarse-grained transport model for neutral particles in turbulent plasmas  

Science Conference Proceedings (OSTI)

The transport of neutral particles in turbulent plasmas is addressed from the prospect of developing coarse-grained transport models which can be implemented in code suites like B2-EIRENE, currently used for designing the ITER divertor. The statistical properties of turbulent fluctuations are described by a multivariate Gamma distribution able to retain space and time correlations through a proper choice of covariance function. We show that in the scattering free case, relevant for molecules and impurity atoms, the average neutral particle density obeys a Boltzmann equation with an ionization rate renormalized by fluctuations. This result lends itself to a straightforward implementation in the EIRENE Monte Carlo solver for neutral particles. Special emphasis is put on the inclusion of time correlations, and in particular on the ballistic motion of coherent turbulent structures. The role of these time dependent effects is discussed for D{sub 2} molecules and beryllium atoms. The sensitivity of our results to the assumptions on the statistical properties of fluctuations is investigated.

Mekkaoui, A.; Reiter, D.; Boerner, P. [IEK-4 Plasmaphysik, Forschungszentrum Juelich GmbH, Euratom Association, D-52425 Juelich (Germany); Marandet, Y.; Genesio, P.; Rosato, J.; Capes, H.; Koubiti, M.; Godbert-Mouret, L.; Stamm, R. [Aix-Marseille Universite, CNRS, PIIM, UMR 7345, F-13397 Marseille Cedex 20 (France)

2012-12-15T23:59:59.000Z

353

MODELING TRANSPORT IN THE DOWN GRADIENT PORTION OF THE 200-PO-1 OPERABLE UNIT AT THE HANFORD SITE  

SciTech Connect

Remedial Investigations are underway for the 200-PO-l Operable Unit (OU) at the U.S. Department of Energy's Hanford Site in Washington State. To support the baseline risk assessment and evaluation of remedial alternatives, fate and transport modeling is being conducted to predict the future concentration of contaminants of potential concern in the 200-PO-1 OU. This study focuses on modeling the 'down gradient' transport of those contaminants that migrate beyond the 3-D model domain selected for performing detailed 'source area' modeling within the 200-PO-1 OU. The down gradient portion is defined as that region of the 200-PO-1 OU that is generally outside the 200 Area (considered 'source area') of the Hanford Site. A 1-D transport model is developed for performing down gradient contaminant fate and transport modeling. The 1-D transport model is deemed adequate based on the inferred transport pathway of tritium in the past and the observation that most of the contaminant mass remains at or near the water table within the unconfined aquifer of the Hanford Formation and the Cold-Creek/Pre-Missoula Gravel unit. The Pipe Pathway feature of the GoldSim software is used to perform the calculations. The Pipe Pathway uses a Laplace transform approach to provide analytical solutions to a broad range of advection-dominated mass transport systems involving one-dimensional advection, longitudinal dispersion, retardation, decay and ingrowth, and exchanges with immobile storage zones. Based on the historical concentration distribution data for the extensive tritium plume in this area, three Pipe Pathways are deemed adequate for modeling transport of contaminants. Each of these three Pipe Pathways is discretized into several zones, based on the saturated thickness variation in the unconfined aquifer and the location of monitoring wells used for risk assessment calculation. The mass fluxes of contaminants predicted to exit the source area model domain are used as an input to the down gradient model, while the flow velocities applied are based on the present-day hydraulic gradients and estimation of hydraulic conductivity in the unconfined aquifer. The results of the calculation indicate that the future concentrations of contaminants of potential concern in the down gradient portion of the 200-PO-1 OU declines with time and distance.

MEHTA S; ALY AH; MILLER CW; MAYENNA A

2009-12-03T23:59:59.000Z

354

The Development and Application of Reactive Transport Modeling Techniques to Study Radionuclide Migration at Yucca Mountain, NV  

SciTech Connect

Yucca Mountain, Nevada has been chosen as a possible site for the first high level radioactive waste repository in the United States. As part of the site investigation studies, we need to make scientifically rigorous estimations of radionuclide migration in the event of a repository breach. Performance assessment models used to make these estimations are computationally intensive. We have developed two reactive transport modeling techniques to simulate radionuclide transport at Yucca Mountain: (1) the selective coupling approach applied to the convection-dispersion-reaction (CDR) model and (2) a reactive stream tube approach (RST). These models were designed to capture the important processes that influence radionuclide migration while being computationally efficient. The conventional method of modeling reactive transport models is to solve a coupled set of multi-dimensional partial differential equations for the relevant chemical components in the system. We have developed an iterative solution technique, denoted the selective coupling method, that represents a versatile alternative to traditional uncoupled iterative techniques and the filly coupled global implicit method. We show that selective coupling results in computational and memory savings relative to these approaches. We develop RST as an alternative to the CDR method for solving large two- or three-dimensional reactive transport simulations for cases in which one is interested in predicting the flux across a specific control plane. In the RST method, the multidimensional problem is reduced to a series of one-dimensional transport simulations along streamlines. The key assumption with RST is that mixing at the control plane approximates the transverse dispersion between streamlines. We compare the CDR and RST approaches for several scenarios that are relevant to the Yucca Mountain Project. For example, we apply the CDR and RST approaches to model an ongoing field experiment called the Unsaturated Zone Transport Test.

Hari Selvi Viswanathan

1999-09-01T23:59:59.000Z

355

Chombo-Crunch: Modeling Pore-Scale Reactive Transport in Carbon  

NLE Websites -- All DOE Office Websites (Extended Search)

Transient pH on calcite grains in capillary tube experiment. 1 billion grid points computed on 48K cores. 1 micron resolution. Transient pH on calcite grains in capillary tube experiment. 1 billion grid points computed on 48K cores. 1 micron resolution. Transient pH on calcite grains in capillary tube experiment. 1 billion grid points computed on 48K cores. 1 micron resolution. David Trebotich, Lawrence Berkeley National Laboratory Chombo-Crunch: Modeling Pore-Scale Reactive Transport in Carbon Sequestration PI Name: David Trebotich PI Email: treb@lbl.gov Institution: Lawrence Berkeley National Laboratory Allocation Program: INCITE Allocation Hours at ALCF: 80 Million Year: 2014 Research Domain: Earth Science Carbon sequestration, the process of capturing carbon dioxide (CO2) before it enters the atmosphere and transferring it into the earth, is a promising technique to help control greenhouse gas emissions. Researchers from the

356

Validation Analysis of the Groundwater Flow and Transport Model of the Central Nevada Test Area  

Science Conference Proceedings (OSTI)

The Central Nevada Test Area (CNTA) is a U.S. Department of Energy (DOE) site undergoing environmental restoration. The CNTA is located about 95 km northeast of Tonopah, Nevada, and 175 km southwest of Ely, Nevada (Figure 1.1). It was the site of the Faultless underground nuclear test conducted by the U.S. Atomic Energy Commission (DOE's predecessor agency) in January 1968. The purposes of this test were to gauge the seismic effects of a relatively large, high-yield detonation completed in Hot Creek Valley (outside the Nevada Test Site [NTS]) and to determine the suitability of the site for future large detonations. The yield of the Faultless underground nuclear test was between 200 kilotons and 1 megaton (DOE, 2000). A three-dimensional flow and transport model was created for the CNTA site (Pohlmann et al., 1999) and determined acceptable by DOE and the Nevada Division of Environmental Protection (NDEP) for predicting contaminant boundaries for the site.

A. Hassan; J. Chapman; H. Bekhit; B. Lyles; K. Pohlmann

2006-09-30T23:59:59.000Z

357

On the Requirements for Realistic Modeling of Neutrino Transport in Simulations of Core-collapse Supernovae  

SciTech Connect

We have conducted a series of numerical experiments with the spherically-symmetric, general-relativistic neutrino radiation hydrodynamics code Agile-BOLTZTRAN to examine the effects of several approximations used in multidimensional core-collapse supernova simulations. Our code permits us to examine the effects of these approximations quantitatively by removing, or substituting for, the pieces of supernova physics of interest. These approximations include: (1) using Newtonian versus general-relativistic gravity, hydrodynamics, and transport; (2) using older weak interactions, including the omission of non-isoenergetic neutrino scattering, versus up-to-date weak interactions; and (3) omitting the velocity-dependent terms, or observer corrections, from the neutrino Boltzmann kinetic equation. We demonstrate that each of these changes has non-negligible effects on the outcomes of our simulations. Finally, we discuss the impact these results have for current, and future, multidimensional models.

Lentz, Eric J [ORNL; Mezzacappa, Anthony [ORNL; Messer, Bronson [ORNL; Liebendoerfer, Matthias [Universitat Basel, Switzerland; Hix, William Raphael [ORNL; Bruenn, S. W. [Florida Atlantic University

2012-01-01T23:59:59.000Z

358

Transport and seismoelectric properties of porous permeable rock : numerical modeling and laboratory measurements  

E-Print Network (OSTI)

The objective of this thesis is to better understand the transport and seismoelectric (SE) properties of porous permeable rock. Accurate information of rock transport properties, together with pore geometry, can aid us to ...

Zhan, Xin, Ph. D. Massachusetts Institute of Technology

2010-01-01T23:59:59.000Z

359

MODELING U TRANSPORT IN THE UNSATURATED ZONE AT PENA BLANCA, MEXICO  

SciTech Connect

We present a quantitative model to describe transport of radionuclides underground. Applicable to unsaturated (vadose) as well as saturated (phreatic) layers, the model provides constraints on the in-situ migratory behavior of radioisotopes in dissolved and colloidal pools of a groundwater system. It shows, for examples, that uranium in water percolating through the vadose zone will have its concentration and ratio {sup 234}U/{sup 238}U linearly correlated under the ideal condition of a constant removal of the two U isotopes from vadose-zone solids. The intercept and slope of the linearity serve to constrain removal rates of the two uranium isotopes from solids to the solution through dissolution and alpha recoil. The model also allows estimation of the fluid transit time in the vadose zone. At Pena Blanca, the uneven distribution of rainfall between winter (wet) and summer (dry) results in a conspicuous seasonal variability in uranium removal rate, hence dissolved uranium signals, within the unsaturated zone. Our data indicate a much higher uranium dissolution rate during the dry season than during the wet season, possibly reflecting a condition of increased oxygenation in the zone during the dry period.

T.L. Ku; S. Luo; M. Murrell; S. Goldstein

2005-07-01T23:59:59.000Z

360

HYDROBIOGEOCHEM: A coupled model of HYDROlogic transport and mixed BIOGEOCHEMical kinetic/equilibrium reactions in saturated-unsaturated media  

Science Conference Proceedings (OSTI)

The computer program HYDROBIOGEOCHEM is a coupled model of HYDROlogic transport and BIOGEOCHEMical kinetic and/or equilibrium reactions in saturated/unsaturated media. HYDROBIOGEOCHEM iteratively solves the two-dimensional transport equations and the ordinary differential and algebraic equations of mixed biogeochemical reactions. The transport equations are solved for all aqueous chemical components and kinetically controlled aqueous species. HYDROBIOGEOCHEM is designed for generic application to reactive transport problems affected by both microbiological and geochemical reactions in subsurface media. Input to the program includes the geometry of the system, the spatial distribution of finite elements and nodes, the properties of the media, the potential chemical and microbial reactions, and the initial and boundary conditions. Output includes the spatial distribution of chemical and microbial concentrations as a function of time and space, and the chemical speciation at user-specified nodes.

Yeh, G.T.; Salvage, K.M. [Pennsylvania State Univ., University Park, PA (United States). Dept. of Civil and Environmental Engineering] [Pennsylvania State Univ., University Park, PA (United States). Dept. of Civil and Environmental Engineering; Gwo, J.P. [Oak Ridge National Lab., TN (United States)] [Oak Ridge National Lab., TN (United States); Zachara, J.M.; Szecsody, J.E. [Pacific Northwest National Lab., Richland, WA (United States)] [Pacific Northwest National Lab., Richland, WA (United States)

1998-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "transportation greet model" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Laboratory And Lysimeter Experimentation And Transport Modeling Of Neptunium And Strontium In Savannah River Site Sediments  

Science Conference Proceedings (OSTI)

The Savannah River Site (SRS) conducts performance assessment (PA) calculations to determine the appropriate amount of low-level radiological waste that can be safely disposed on site. Parameters are included in these calculations that account for the interaction between the immobile solid phase and the mobile aqueous phase. These parameters are either the distribution coefficient (K{sub d} value) or the apparent solubility value (K{sub sp}). These parameters are readily found in the literature and are used throughout the DOE complex. One shortcoming of K{sub d} values is that they are only applicable to a given set of solid and aqueous phase conditions. Therefore, a given radionuclide may have several K{sub d} values as it moves between formations and comes into contact with different solids and different aqueous phases. It is expected that the K{sub d} construct will be appropriate to use for a majority of the PA and for a majority of the radionuclides. However, semi-mechanistic models would be more representative in isolated cases where the chemistry is especially transitory or the radionuclide chemistry is especially complex, bringing to bear multiple species of varying sorption tendencies to the sediment. Semi-mechanistic models explicitly accommodate the dependency of K{sub d} values, or other sorption parameters, on contaminant concentration, competing ion concentrations, pH-dependent surface charge on the adsorbent, and solute species distribution. Incorporating semi-mechanistic concepts into geochemical models is desirable to make the models more robust and technically defensible. Furthermore, these alternative models could be used to augment or validate a Kd?based DOE Order 435.1 Performance Assessment. The objectives of this study were to: 1) develop a quantitative thermodynamically-based model for neptunium sorption to SRS sediments, and 2) determine a sorption constant from an SRS 11-year lysimeter study. The modeling studies were conducted with existing data sets. The first data set used laboratory generated Np sorption data as a function of concentration (three orders of magnitude) and as a function of pH (four orders of magnitude of proton concentration). In this modeling exercise, a very simple solution was identified by assuming that all sorption occurred only to the iron oxides in the sediment and that all the added NpO{sub 4}{sup -} remained in the oxidized state and was not reduced to the Np(IV) state (as occurs rapidly with Pu(V)). With rather limited input data, very good agreement between experimental and modeling results was observed. This modeling approach would be easy to add to the PA with little additional data requirements. This model would be useful in a system where pH is expected to change greatly, such as directly beneath a grout or concrete structure. The second model discussed in the report was to derive strontium K{sub d} values from data collected in an 11-year-old field transport study. In this controlled lysimeter study, a sensitivity analysis was conducted of hydrological and chemical processes that influence contaminant transport, including diffusion coefficients, seepage velocity, and K{sub d} value. The best overall K{sub d} derived from the model fit to the data was 32 L kg{sup -1}, which was the same value that was previously measured in traditional laboratory batch sorption studies. This was an unexpected result given the differences in experimental conditions between the batch test and the lysimeter flow through test, in particular the differences between strontium adsorption and desorption processes occurring in the latter test and not in the former. There were some trends in the lysimeter strontium data that were not predicted by the K{sub d} model, which suggest that other geochemical processes are likely also controlling strontium transport. Strontium release and cation exchange are being evaluated. These results suggest that future modeling efforts (e.g., PAs) could be improved by employing a more robust semi-empirical modeling approach to transient or complex conditio

Kaplan, Daniel I.; Powell, B. A.; Miller, Todd J.

2012-09-24T23:59:59.000Z

362

Variably Saturated Flow and Multicomponent Biogeochemical Reactive Transport Modeling of a Uranium Bioremediation Field Experiment  

Science Conference Proceedings (OSTI)

Field experiments at a former uranium mill tailings site have identified the potential for stimulating indigenous bacteria to catalyze the conversion of aqueous uranium in the +6 oxidation state to immobile solid-associated uranium in the +4 oxidation state. This effectively removes uranium from solution resulting in groundwater concentrations below actionable standards. Three-dimensional, coupled variably-saturated flow and biogeochemical reactive transport modeling of a 2008 in situ uranium bioremediation field experiment is used to better understand the interplay of transport rates and biogeochemical reaction rates that determine the location and magnitude of key reaction products. A comprehensive reaction network, developed largely through previous 1-D modeling studies, was used to simulate the impacts on uranium behavior of pulsed acetate amendment, seasonal water table variation, spatially-variable physical (hydraulic conductivity, porosity) and geochemical (reactive surface area) material properties. A principal challenge is the mechanistic representation of biologically-mediated terminal electron acceptor process (TEAP) reactions whose products significantly alter geochemical controls on uranium mobility through increases in pH, alkalinity, exchangeable cations, and highly reactive reduction products. In general, these simulations of the 2008 Big Rusty acetate biostimulation field experiment in Rifle, Colorado confirmed previously identified behaviors including (1) initial dominance by iron reducing bacteria that concomitantly reduce aqueous U(VI), (2) sulfate reducing bacteria that become dominant after {approx}30 days and outcompete iron reducers for the acetate electron donor, (3) continuing iron-reducer activity and U(VI) bioreduction during dominantly sulfate reducing conditions, and (4) lower apparent U(VI) removal from groundwater during dominantly sulfate reducing conditions. New knowledge on simultaneously active metal and sulfate reducers has been incorporated into the modeling. In this case, an initially small population of slow growing sulfate reducers is active from the initiation of biostimulation. Three-dimensional, variably saturated flow modeling was used to address impacts of a falling water table during acetate injection. These impacts included a significant reduction in aquifer saturated thickness and isolation of residual reactants and products, as well as unmitigated uranium, in the newly unsaturated vadose zone. High permeability sandy gravel structures resulted in locally high flow rates in the vicinity of injection wells that increased acetate dilution. In downgradient locations, these structures created preferential flow paths for acetate delivery that enhanced local zones of TEAP reactivity and subsidiary reactions. Conversely, smaller transport rates associated with the lower permeability lithofacies (e.g., fine) and vadose zone were shown to limit acetate access and reaction. Once accessed by acetate, however, these same zones limited subsequent acetate dilution and provided longer residence times that resulted in higher concentrations of TEAP products when terminal electron donors and acceptors were not limiting. Finally, facies-based porosity and reactive surface area variations were shown to affect aqueous uranium concentration distributions; however, the ranges were sufficiently small to preserve general trends. Large computer memory and high computational performance were required to simulate the detailed coupled process models for multiple biogeochemical components in highly resolved heterogeneous materials for the 110-day field experiment and 50 days of post-biostimulation behavior. In this case, a highly-scalable subsurface simulator operating on 128 processor cores for 12 hours was used to simulate each realization. An equivalent simulation without parallel processing would have taken 60 days, assuming sufficient memory was available.

Yabusaki, Steven B.; Fang, Yilin; Williams, Kenneth H.; Murray, Christopher J.; Ward, Anderson L.; Dayvault, Richard; Waichler, Scott R.; Newcomer, Darrell R.; Spane, Frank A.; Long, Philip E.

2011-11-01T23:59:59.000Z

363

Transportation Demand  

Gasoline and Diesel Fuel Update (EIA)

page intentionally left blank page intentionally left blank 69 U.S. Energy Information Administration | Assumptions to the Annual Energy Outlook 2011 Transportation Demand Module The NEMS Transportation Demand Module estimates transportation energy consumption across the nine Census Divisions (see Figure 5) and over ten fuel types. Each fuel type is modeled according to fuel-specific technology attributes applicable by transportation mode. Total transportation energy consumption is the sum of energy use in eight transport modes: light-duty vehicles (cars and light trucks), commercial light trucks (8,501-10,000 lbs gross vehicle weight), freight trucks (>10,000 lbs gross vehicle weight), buses, freight and passenger aircraft, freight and passenger rail, freight shipping, and miscellaneous

364

Modeling Bimolecular Reactions and Transport in Porous Media Via Particle Tracking  

Science Conference Proceedings (OSTI)

We use a particle-tracking method to simulate several one-dimensional bimolecular reactive transport experiments. In this numerical method, the reactants are represented by particles: advection and dispersion dominate the flow, and molecular diffusion dictates, in large part, the reactions. The particle/particle reactions are determined by a combination of two probabilities dictated by the physics of transport and energetics of reaction. The first is that reactant particles occupy the same volume over a short time interval. The second is the conditional probability that two collocated particles favorably transform into a reaction. The first probability is a direct physical representation of the degree of mixing in an advancing displacement front, and as such lacks empirical parameters except for the user-defined number of particles. This number can be determined analytically from concentration autocovariance, if this type of data is available. The simulations compare favorably to two physical experiments. In one, the concentration of product, 1,2-naphthoquinoe-4-aminobenzene (NQAB) from reaction between 1,2-naphthoquinone-4-sulfonic acid (NQS) and aniline (AN), was measured at the outflow of a column filled with glass beads at different times. In the other, the concentration distribution of reactants (CuSO_4 and EDTA^{4-}) and products (CuEDTA^{4-}) were quantified by snapshots of transmitted light through a column packed with cryloite sand. The thermodynamic rate coefficient in the latter experiment was 10^7 times greater than the former experiment, making it essentially instantaneous. When compared to the solution of the advection-dispersion-reaction equation (ADRE) with the well-mixed reaction coefficient, the experiments and the particle-tracking simulations showed on the order of 20% to 40% less overall product, which is attributed to poor mixing. The poor mixing also leads to higher product concentrations on the edges of the mixing zones, which the particle model simulates more accurately than the ADRE.

Dong Ding; David Benson; Amir Paster; Diogo Bolster

2012-01-01T23:59:59.000Z

365

Reaction-Based Reactive Transport Modeling of Fe(III) and U(V) Reduction  

SciTech Connect

Our new research project (started Fall 2004) was funded by a grant to The Pennsylvania State University, University of Central Florida, and The University of Alabama in the Integrative Studies Element of the NABIR Program (DE-FG04-ER63914/63915/63196). Our previous NABIR project (DE-FG02-01ER63180/63181/63182, funded within the Biotransformation Element) focused on (1) microbial reduction of Fe(III) and U(VI) individually, and concomitantly in natural sediments, (2) Fe(III) oxide surface chemistry, specifically with respect to reactions with Fe(II) and U(VI), (3) the influence of humic substances on Fe(III) and U(VI) bioreduction, and on U(VI) complexation, and (4) the development of reaction-based reactive transport biogeochemical models to numerically simulate our experimental results. The new project focuses on the development of a mechanistic understanding and quantitative models of coupled Fe(III)/U(VI) reduction in FRC Area 2 sediments. This work builds on our previous studies of microbial Fe(III) and U(VI) reduction, and is directly aligned with the Scheibe et al. NABIR FRC Field Project at Area 2.

Burgos, William D.; Roden, Eric E.; Yeh, Gour-Tsyh

2005-06-01T23:59:59.000Z

366

MODELLING OF COUPLED GROUNDWATER FLOW AND RADIONUCLIDE TRANSPORT IN CRYSTALLINE BASEMENT USING FEFLOW 5.0  

E-Print Network (OSTI)

Abstract. The strategy of radioactive waste management of Lithuania provides for evaluating the possibilities of disposal of spent nuclear fuel and long-lived radioactive waste originated from Ignalina NPP in deep geological formations. The initial studies performed in Lithuania during 20012004 focused on screening of all potentially prospective geological formations as host formations. Since most information is available on crystalline basement, this formation was selected for the model case studies. Taking into account the assumptions (canister defect scenario proposed by Swedish experts and evaluated by LEI experts), groundwater flow and radionuclide (iodine-129 as mobile and long-lived one) transport modelling using computer code FEFLOW was performed according to geosphere conditions and parameters characteristic of the southern part of Lithuania (0,80,60,52 km far-field block). The upward groundwater flow through defected canister located in tectonically damaged zone was simulated. The main results of calculations are the following: in the case of upward groundwater flow, the maximum I-129 volumetric activity in single tectonic fracture above defected canister will not exceed 1 Bq/l, and in the active water exchange zone, it is close to 10-2 Bq/l. These figures show that doses obtained by human recipient via aquatic pathway should be below the dose constraint (0,2 mSv/y). More complicated scenarios and assumptions should be investigated in future studies.

Vaidot? Jakimavi?i?t?-maselien?; Jonas Maeika; Rimantas Petroius

2006-01-01T23:59:59.000Z

367

Effect of turbulent transport models and grid spacing on pans calculations of a lid-driven cavity  

E-Print Network (OSTI)

The three-dimensional lid-driven cavity flow is investigated at Reynolds Number(Re)=10,000 for a wide range of spanwise-aspect ratios of 3:1:1, 0.5:1:1, and 1:1:1 using the Partially Averaged Navier-Stokes(PANS) turbulence closure model. The PANS turbulence model is a variable resolution turbulence closure model, where the unresolved-to-total ratios of kinetic energy (fk) and dissipation (fe), serve as resolution control parameters. This study focuses on two main aspects of PANS: (i) the evaluation of Turbulent transport models and (ii) the effect of grid spacing on accuracy of the numerical solution. PANS calculations are tested against LES and experimental results of Jordan (1994), in terms of both qualitative and quantitative quantities. The main coclusions are are: (i) for a given fk value, the Zero-Transport model is superior to the Maximum-Transport model for unresolved dissipation, (ii) both models are adequate for unresolved kinetic energy, and (iii) for a given grid size, the results depend heavily on grid spacing especially for larger fk values.

Murthi, Aditya

2004-08-01T23:59:59.000Z

368

Unstructured finite volume discretisation of bed friction and convective flux in solute transport models linked to the shallow water equations  

Science Conference Proceedings (OSTI)

The finite volume discretisation of the shallow water equations has been the subject of many previous studies, most of which deal with a well-balanced conservative discretisation of the convective flux and bathymetry. However, the bed friction discretisation ... Keywords: Bed friction, Depth averaged models, Finite volume method, High order schemes, Scalar transport, Shallow water equations, Unstructured mesh

L. Cea; M. E. Vzquez-Cendn

2012-04-01T23:59:59.000Z

369

A reactive transport modeling approach to simulate biogeochemical processes in pore structures with pore-scale heterogeneities  

Science Conference Proceedings (OSTI)

Redox processes, including degradation of organic contaminants, are often controlled by microorganisms residing in natural porous media like soils or aquifers. These environments are characterized by heterogeneities at various scales which influence ... Keywords: Bioavailability, Biodegradation, Pore networks, Pore-scale heterogeneity, Reactive transport models, Spatial distributions

Mehdi Gharasoo; Florian Centler; Pierre Regnier; Hauke Harms; Martin Thullner

2012-04-01T23:59:59.000Z

370

Evaluation of the integrated application of intelligent transportation system technologies using stochastic incident generation and resolution modeling  

Science Conference Proceedings (OSTI)

This paper presents the use of the microscopic vehicle traffic simulation software PARAMICS to evaluate different incident management implementation alternatives in South Carolina. This study customized the simulation model for random spatial and temporal ... Keywords: freeway service patrol, intelligent transportation systems, traffic incident management, traffic simulation

Yongchang Ma; Ryan Fries; Mashrur Chowdhury; Imran Inamdar

2012-01-01T23:59:59.000Z

371

Comparison of Average Transport and Dispersion Among a Gaussian Model, a Two-Dimensional Model and a Three-Dimensional Model  

Science Conference Proceedings (OSTI)

The Nuclear Regulatory Commission uses MACCS2 (MELCOR Accident Consequence Code System, Version 2) for regulatory purposes such as planning for emergencies and cost-benefit analyses. MACCS2 uses a straight-line Gaussian model for atmospheric transport and dispersion. This model has been criticized as being overly simplistic, although only expected values of metrics of interest are used in the regulatory arena. To test the assumption that averaging numerous weather results adequately compensates for the loss of structure in the meteorology that occurs away from the point of release, average MACCS2 results have been compared with average results from a state-of-the-art, 3-dimensional LODI (Lagrangian Operational Dispersion Integrator)/ADAPT (Atmospheric Data Assimilation and Parameterization Technique) and a Lagrangian trajectory, Gaussian puff transport and dispersion model from RASCAL (Radiological Assessment System for consequence Analysis). The weather sample included 610 weather trials representing conditions for a hypothetical release at the Central Facility of the Department of Energy's Atmospheric Radiation Measurement site. The values compared were average ground concentrations and average surface-level air concentrations at several distances out to 100 miles (160.9 km) from the assumed release site.

Mitchell, J A; Molenkamp, C R; Bixler, N E; Morrow, C W; Ramsdell, Jr., J V

2004-05-10T23:59:59.000Z

372

Evaluation of the existing performance models used for pavement management by the Texas Department of Transportation  

E-Print Network (OSTI)

The pavement management information system (PMIS) and hics. the flexible pavement design software, FPS-19, used by the Texas Department of Transportation (TxDOT) for pavement management at network and project level respectively, generally do not give the same answer when the same set of data are used. This thesis is a part of the study to develop an approach for integrating pavement management systems at the two levels. The objective of the study is to identify which performance models were working satisfactorily and which needed to be modified. The performance models for ride quality (serviceability index for FPS-19), shallow rutting, deep rutting, and alligator cracking, which are the fundamental performance measures of the flexible pavements, were selected for evaluation. From the family of flexible pavements, the newly constructed pavements with untreated base were considered in the evaluation. A sensitivity analysis was performed to determine the relative importance of the input variables to FPS-I9 program. To reduce the number of problems to a manageable size, a one factor at a time approach was used. The F-statistics corresponding to the relevant input variables were used to determine the ranks. It was found that reliability level is the most important factor in FPS-19, followed by twenty-year projected axle repetition (ESAL). A research database was created by extracting data from the Long Term Pavement Performance (LTPP) database for pavement sections in Texas. A11 data items except rutting data were extracted using the software, Database 97. Rutting data was obtained from the LTPP regional office. Data from sixteen pavement sections were available for the evaluation. Elastic moduli of pavement layers and subgrades were back-calculated using MODULUS software. The selected performance models were evaluated using trend analyses, statistical hypotheses tests, percent difference, and estimated reliability. Due to the lack of data, all members of the performance model families could not be checked. It was observed that none of the selected performance models of PMIS and FPS-I9 is predicting the values observed at the LTPP sites though some of them are predicting better than others. Therefore, improvements are recommended for all the evaluated performance models.

Mukherjee, Biswajit

1998-01-01T23:59:59.000Z

373

Phase I Contaminant Transport Parameters for the Groundwater Flow and Contaminant Transport Model of Corrective Action Unit 99: Rainier Mesa/Shoshone Mountain, Nevada Test Site, Nye County, Nevada, Revision 1  

SciTech Connect

This document presents a summary and framework of available transport data and other information directly relevant to the development of the Rainier Mesa/Shoshone Mountain (RMSM) Corrective Action Unit (CAU) 99 groundwater transport model. Where appropriate, data and information documented elsewhere are briefly summarized with reference to the complete documentation.

Nathan Bryant

2008-05-01T23:59:59.000Z

374

Modeling the Canadian Electric System to Analyze the CO2 Content of Electric Transportation Fuel  

Science Conference Proceedings (OSTI)

Replacing fossil fuel with electricity for transportation can play an important role in reducing CO2 emissions provided the electricity can be used efficiently and can be produced without emitting significant amounts of CO2. Canada offers a particularly attractive opportunity to replace fossil fuels with electricity in the transportation sector because Canada has historically generated electricity with low emissions of CO2 and because the transportation sector is responsible for a larger percentage of na...

2010-12-17T23:59:59.000Z

375

Laboratory, Field, and Modeling Analysis of Solute Transport Behavior at the Shale Hills Critical Zone Observatory.  

E-Print Network (OSTI)

??We collected and analyzed breakthrough curve (BTC) data to identify the parameters controlling transport from a series of undisturbed fully saturated soil cores and a (more)

Kuntz, Brad

2010-01-01T23:59:59.000Z

376

Efficient Schemes for Reducing Numerical Dispersion in Modeling Multiphase Transport through Porous and Fractured Media  

E-Print Network (OSTI)

involved. These heat-transfer processes are complicated byprocesses of multiphase flow, chemical transport, and heat transfertransport, and heat transfer, we assume that these processes

Wu, Yu-Shu; Forsyth, Peter A.

2006-01-01T23:59:59.000Z

377

Argonne Transportation - Clean Cities Area of Interest 4: Alternative Fuel,  

NLE Websites -- All DOE Office Websites (Extended Search)

Clean Cities Area of Interest 4: Alternative Fuel and Advanced Technology Vehicles Pilot Program Emissions Benefit Tool Download Clean Cities Area of Interest 4 Emissions Benefit Tool (Excel 57 KB) This tool has been created for the Clean Cities Funding Opportunity Announcement for Area of Interest 4: Alternative Fuel and Advanced Technology Vehicles Pilot Program. The tool is based off the AirCRED model's methodology using EPA's MOBILE6 model and light duty vehicle and heavy duty engine certification data to generate criteria air pollutant emission credits. However, for this tool, the GREET model is also used to generate data for vehicles not certified and well-to-wheel greenhouse gas emissions. This tool requires the user to input: The number of vehicles planned to be purchased

378

A Reaction-Transport Model for Calcite Precipitation andEvaluation of Infiltration Fluxes in unsaturated fractured rock  

Science Conference Proceedings (OSTI)

The percolation flux in the unsaturated zone (UZ) is an important parameter addressed in site characterization and flow and transport modeling of the potential nuclear-waste repository at Yucca Mountain, NV, USA. The US Geological Survey (USGS) has documented hydrogenic calcite abundances in fractures and lithophysal cavities at Yucca Mountain to provide constraints on percolation fluxes in the UZ. The purpose of this study was to investigate the relationship between percolation flux and measured calcite abundances using reactive transport modeling. Our model considers the following essential factors affecting calcite precipitation: (1) infiltration, (2) the ambient geothermal gradient, (3) gaseous CO2 diffusive transport and partitioning in liquid and gas phases, (4) fracture matrix interaction for water flow and chemical constituents, and (5) water rock interaction. Over a bounding range of 2 20 mm/year infiltration rate, the simulated calcite distributions capture the trend in calcite abundances measured in a deep borehole (WT-24) by the USGS. The calcite is found predominantly in fractures in the welded tuffs, which is also captured by the model simulations. Simulations showed that from about 2 to 6 mm/year, the amount of calcite precipitated in the welded Topopah Spring tuff is sensitive to the infiltration rate. This dependence decreases at higher infiltration rates owing to a modification of the geothermal gradient from the increased percolation flux. The model also confirms the conceptual model for higher percolation fluxes in the fractures compared to the matrix in the welded units, and the significant contribution of Ca from water rock interaction. This study indicates that reactive transport modeling of calcite deposition can yield important constraints on the unsaturated zone infiltration-percolation flux and provide useful insight into processes such as fracture matrix interaction as well as conditions and parameters controlling calcite deposition.

Xu, Tianfu; Sonnenthal, Eric; Bodvarsson, Gudmundur

2001-06-15T23:59:59.000Z

379

The modeling of mode choices of intercity freight transportation with the artificial neural networks and adaptive neuro-fuzzy inference system  

Science Conference Proceedings (OSTI)

Mode choice modeling is probably the most important element of transportation planning. It affects the general efficiency of travel and the allocation of resources. The development of mode choice models has recently witnessed significant advances in ... Keywords: Freight transportation, Fuzzy logic, Hybrid algorithm, Inference system, Mode choices, Neural networks, Neuro-fuzzy

Ahmet Tortum; Nadir Yayla; Mahir Gkda?

2009-04-01T23:59:59.000Z

380

ON THE REQUIREMENTS FOR REALISTIC MODELING OF NEUTRINO TRANSPORT IN SIMULATIONS OF CORE-COLLAPSE SUPERNOVAE  

SciTech Connect

We have conducted a series of numerical experiments with the spherically symmetric, general relativistic, neutrino radiation hydrodynamics code AGILE-BOLTZTRAN to examine the effects of several approximations used in multidimensional core-collapse supernova simulations. Our code permits us to examine the effects of these approximations quantitatively by removing, or substituting for, the pieces of supernova physics of interest. These approximations include: (1) using Newtonian versus general relativistic gravity, hydrodynamics, and transport; (2) using a reduced set of weak interactions, including the omission of non-isoenergetic neutrino scattering, versus the current state-of-the-art; and (3) omitting the velocity-dependent terms, or observer corrections, from the neutrino Boltzmann kinetic equation. We demonstrate that each of these changes has noticeable effects on the outcomes of our simulations. Of these, we find that the omission of observer corrections is particularly detrimental to the potential for neutrino-driven explosions and exhibits a failure to conserve lepton number. Finally, we discuss the impact of these results on our understanding of current, and the requirements for future, multidimensional models.

Lentz, Eric J. [Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996-1200 (United States); Mezzacappa, Anthony; Hix, W. Raphael [Physics Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6354 (United States); Messer, O. E. Bronson [Computer Science and Mathematics Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6164 (United States); Liebendoerfer, Matthias [Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland); Bruenn, Stephen W., E-mail: elentz@utk.edu, E-mail: mezzacappaa@ornl.gov [Department of Physics, Florida Atlantic University, 777 Glades Road, Boca Raton, FL 33431-0991 (United States)

2012-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "transportation greet model" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

TACK: a program coupling chemical kinetics with a two-dimensional transport model in geochemical systems  

Science Conference Proceedings (OSTI)

The Transport And Chemical Kinetics (TACK) program has been designed to make predictions of the chemistry in the vicinity of a planned repository for nuclear waste, i.e. SFL 3-5, where SFL is the Swedish abbreviation for "Swedish repository for long-lived ... Keywords: coupled, diffusion, dispersion, reaction, transport, two-dimensional

Gran Kllvenius; Christian Ekberg

2003-05-01T23:59:59.000Z

382

Developing model-based software to optimise wheat storage and transportation: A real-world application  

Science Conference Proceedings (OSTI)

This paper investigates a real-world case of a logistical management problem. We determine the optimal amounts of wheat to be transported from each producing province to each consuming province per month across the year. The problem was formulated as ... Keywords: Agriculture, Genetic algorithm, Inventory, Linear integer programming, Transportation

Nasrin Asgari; Reza Zanjirani Farahani; Hannaneh Rashidi-Bajgan; Mohsen S. Sajadieh

2013-02-01T23:59:59.000Z

383

IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS, VOL. 10, NO. 1, JANUARY/FEBRUARY 2004 37 Monte Carlo Modeling of the Light Transport in  

E-Print Network (OSTI)

absorption, thin-film coatings, and uneven or irregular surfaces by tracking the photon polarization aerogel layer [10]. Several models have also been proposed for modeling optical transport in organic light

Kanicki, Jerzy

384

Life-Cycle Analysis of Vehicle and Fuel Systems with the GREET Model - DOE Hydrogen and Fuel Cells Program FY 2012 Annual Progress Report  

NLE Websites -- All DOE Office Websites (Extended Search)

5 5 FY 2012 Annual Progress Report DOE Hydrogen and Fuel Cells Program Michael Wang (Primary Contact), Amgad Elgowainy, Jeongwoo Han and Hao Cai Argonne National Laboratory (ANL) ESD362 9700 South Cass Avenue Argonne, IL 60439 Phone: (630) 252-2819 Email: mqwang@anl.gov DOE Manager HQ: Fred Joseck Phone: (202) 586-7932 Email: Fred.Joseck@ee.doe.gov Project Start Date: October 2009 Project End Date: Project continuation and direction determined annually by DOE Fiscal Year (FY) 2012 Objectives Evaluate environmental benefits of hydrogen fuel * cell electric vehicles (FCEVs) with various renewable hydrogen production pathways relative to baseline gasoline pathways. Conduct vehicle-cycle analysis of hydrogen FCEVs. *

385

A mountain-scale model for characterizing unsaturated flow and transport in fractured tuffs of Yucca Mountain  

E-Print Network (OSTI)

development and analysis of radionuclide transport in theinvestigate fluid flow and radionuclide transport processeson moisture flow and radionuclide transport within or near

Wu, Yu-Shu; Lu, Guoping; Zhang, Keni; Bodvarsson, G.S.

2003-01-01T23:59:59.000Z

386

Transportation Sector Module  

Reports and Publications (EIA)

Documents the objectives, analytical approach and development of the National Energy Modeling System (NEMS) Transportation Model (TRAN). The report catalogues and describes the model assumptions, computational methodology, parameter estimation techniques, model source code, and forecast results generated by the model.

John Maples

2012-10-31T23:59:59.000Z

387

Transportation Sector Module  

Reports and Publications (EIA)

Documents the objectives, analytical approach and development of the National Energy Modeling System (NEMS) Transportation Model (TRAN). The report catalogues and describes the model assumptions, computational methodology, parameter estimation techniques, model source code, and forecast results generated by the model.

John Maples

2013-09-05T23:59:59.000Z

388

Modeling of the Coastal Boundary Layer and Pollutant Transport in New England  

Science Conference Proceedings (OSTI)

Concentrations of ozone exceeding regulatory standards are regularly observed along the coasts of New Hampshire and Maine in summer. These events are primarily caused by the transport of pollutants from urban areas in Massachusetts and farther ...

Wayne M. Angevine; Michael Tjernstrm; Mark agar

2006-01-01T23:59:59.000Z

389

Simulating groundwater transport process using a vertical heterogeneity model: a case study  

Science Conference Proceedings (OSTI)

It is important to simulate a groundwater transport process, e.g., pollutant migration, through the vadose zone and subsequent mixing within the saturated zone to assess potential impacts of contaminants in the subsurface in preliminary stages. It is ...

Samuel S. Lee; Hoh Peter In

2004-10-01T23:59:59.000Z

390

Modeling the Transport Sector: The Role of Existing Fuel Taxes in Climate Policy  

E-Print Network (OSTI)

Existing fuel taxes play a major role in determining the welfare effects of exempting the transportation sector from measures to control greenhouse gases. To study this phenomenon we modify the MIT Emissions Prediction and ...

Paltsev, Sergey.

391

Effects of Convective Momentum Transport on the Atmospheric Circulation in the Community Atmosphere Model, Version 3  

Science Conference Proceedings (OSTI)

Transport of momentum by convection is an important process affecting global circulation. Owing to the lack of global observations, the quantification of the impact of this process on the tropospheric climate is difficult. Here an implementation ...

Jadwiga H. Richter; Philip J. Rasch

2008-04-01T23:59:59.000Z

392

Efficient Conservative Global Transport Schemes for Climate and Atmospheric Chemistry Models  

Science Conference Proceedings (OSTI)

A computationally efficient mass-conservative transport scheme over the sphere is proposed and tested. The scheme combines a conservative finite-volume method with an efficient semi-Lagrangian scheme based on the dimension splitting cascade ...

Ramachandran D. Nair; Jeffrey S. Scroggs; Fredrick H. M. Semazzi

2002-08-01T23:59:59.000Z

393

Transportation Secure Data Center: Real-World Data for Planning, Modeling and Analysis (Fact Sheet)  

SciTech Connect

The National Renewable Energy Laboratory (NREL) and the U.S. Department of Transportation (DOT) have launched the free, web-based Transportation Secure Data Center (TSDC). The TSDC (www.nrel.gov/tsdc) preserves respondent anonymity while making vital transportation data available to a broad group of users through secure, online access. The TSDC database gives, metropolitan planning organizations, universities, national laboratories, air quality management districts, disaster planning agencies and auto manufacturers free-of-charge web-based access to valuable transportation data. The TSDC's two levels of access make composite data available with simple online registration, and allow researchers to use detailed spatial data after completing a straight forward application process.

Not Available

2013-01-01T23:59:59.000Z

394

The Use of Spline Interpolation in Semi-Lagrangian Transport Models  

Science Conference Proceedings (OSTI)

The accuracy of interpolating semi-Lagrangian (SL) discretization methods depends on the choice of the interpolating function. Results from barotropic transport simulations on the sphere are presented, using either bicubic Lagrangian or bicubic ...

L. P. Riishjgaard; S. E. Cohn; Y. Li; R. Mnard

1998-07-01T23:59:59.000Z

395

Flow and solute transport in random cylinder arrays : a model for emergent aquatic plant canopies  

E-Print Network (OSTI)

With wetlands constituting about 6% of earth's land surface, aquatic vegetation plays a significant role in defining mean flow patterns and in the transport of dissolved and particulate material in the environment. However, ...

Tanino, Yukie, 1980-

2008-01-01T23:59:59.000Z

396

Comparisons of Transport and Dispersion Model Predictions of the Joint Urban 2003 Field Experiment  

Science Conference Proceedings (OSTI)

For a hazardous material release in a city or densely populated area, effective mitigation requires an understanding of the transport and dispersion of these hazards in the complex urban environment. Improved characterization and understanding of ...

Steve Warner; Nathan Platt; Jeffry T. Urban; James F. Heagy

2008-07-01T23:59:59.000Z

397

The Effects of Cumulus Moisture Transports on the Simulation of Climate with a General Circulation Model  

Science Conference Proceedings (OSTI)

A hybrid cumulus parameterization was developed to study the effects of cumulus heat and moisture transports on climate simulations. This parameterization consists of a cumulus mass flux representation of the convective fluxes of heat and ...

Bruce A. Albrecht; V. Ramanathan; Byron A. Boville

1986-11-01T23:59:59.000Z

398

Phase I Contaminant Transport Parameters for the Groundwater Flow and Contaminant Transport Model of Corrective Action Unit 97: Yucca Flat/Climax Mine, Nevada Test Site, Nye County, Nevada, Revision 0  

Science Conference Proceedings (OSTI)

This report documents transport data and data analyses for Yucca Flat/Climax Mine CAU 97. The purpose of the data compilation and related analyses is to provide the primary reference to support parameterization of the Yucca Flat/Climax Mine CAU transport model. Specific task objectives were as follows: Identify and compile currently available transport parameter data and supporting information that may be relevant to the Yucca Flat/Climax Mine CAU. Assess the level of quality of the data and associated documentation. Analyze the data to derive expected values and estimates of the associated uncertainty and variability. The scope of this document includes the compilation and assessment of data and information relevant to transport parameters for the Yucca Flat/Climax Mine CAU subsurface within the context of unclassified source-term contamination. Data types of interest include mineralogy, aqueous chemistry, matrix and effective porosity, dispersivity, matrix diffusion, matrix and fracture sorption, and colloid-facilitated transport parameters.

John McCord

2007-09-01T23:59:59.000Z

399

Phase II Transport Model of Corrective Action Unit 98: Frenchman Flat, Nevada Test Site, Nye County, Nevada, Revision 1  

Science Conference Proceedings (OSTI)

This document, the Phase II Frenchman Flat transport report, presents the results of radionuclide transport simulations that incorporate groundwater radionuclide transport model statistical and structural uncertainty, and lead to forecasts of the contaminant boundary (CB) for a set of representative models from an ensemble of possible models. This work, as described in the Federal Facility Agreement and Consent Order (FFACO) Underground Test Area (UGTA) strategy (FFACO, 1996; amended 2010), forms an essential part of the technical basis for subsequent negotiation of the compliance boundary of the Frenchman Flat corrective action unit (CAU) by Nevada Division of Environmental Protection (NDEP) and National Nuclear Security Administration Nevada Site Office (NNSA/NSO). Underground nuclear testing via deep vertical shafts was conducted at the Nevada Test Site (NTS) from 1951 until 1992. The Frenchman Flat area, the subject of this report, was used for seven years, with 10 underground nuclear tests being conducted. The U.S. Department of Energy (DOE), NNSA/NSO initiated the UGTA Project to assess and evaluate the effects of underground nuclear tests on groundwater at the NTS and vicinity through the FFACO (1996, amended 2010). The processes that will be used to complete UGTA corrective actions are described in the Corrective Action Strategy in the FFACO Appendix VI, Revision No. 2 (February 20, 2008).

Gregg Ruskuaff

2010-01-01T23:59:59.000Z

400

PRISM 2.0: Personal Transportation Module of the U.S. Regional Economy, Greenhouse Gas, and Energy (US-REGEN) Model: A Guide to Operation and Development  

Science Conference Proceedings (OSTI)

The personal transportation/electric vehicle penetration module (Transportation Module) of the U.S. Regional Economy, Greenhouse Gas, and Energy (US-REGEN) integrated regional macroeconomic model is a structural economic model of personal vehicle purchase and driving behaviors that focuses on the adoption of electric vehicles. The module employs a representation of consumers demographics, existing vehicles, vehicle choices, and preferences for vehicle characteristics to model personal vehicle ...

2013-09-26T23:59:59.000Z

Note: This page contains sample records for the topic "transportation greet model" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Numerical Modeling of Coupled Variably-Saturated Fluid Flow and Reactive Transport with Fast and Slow Chemical Reactions  

SciTech Connect

The couplings among chemical reaction rates, advective and diffusive transport in fractured media or soils, and changes in hydraulic properties due to precipitation and dissolution within fractures and in rock matrix are important for both nuclear waste disposal and remediation of contaminated sites. This paper describes the development and application of LEHGC2.0, a mechanistically-based numerical model for simulation of coupled fluid flow and reactive chemical transport including both fast and slow reactions invariably saturated media. Theoretical bases and numerical implementations are summarized, and two example problems are demonstrated. The first example deals with the effect of precipitation-dissolution on fluid flow and matrix diffusion in a two-dimensional fractured media. Because of the precipitation and decreased diffusion of solute from the fracture into the matrix, retardation in the fractured medium is not as large as the case wherein interactions between chemical reactions and transport are not considered. The second example focuses on a complicated but realistic advective-dispersive-reactive transport problem. This example exemplifies the need for innovative numerical algorithms to solve problems involving stiff geochemical reactions.

LI, MING-HSU; SIEGEL, MALCOLM D.; YEH, GOUR-TSYH (GEORGE)

1999-09-20T23:59:59.000Z

402

Modeling Three-Dimensional Groundwater Flow and Advective Contaminant Transport at a Heterogeneous Mountainous Site in Support of Remediation Strategy  

SciTech Connect

A calibrated groundwater flow model for a contaminated site can provide substantial information for assessing and improving hydraulic measures implemented for remediation. A three-dimensional transient groundwater flow model was developed for a contaminated mountainous site, at which interim corrective measures were initiated to limit further spreading of contaminants. This flow model accounts for complex geologic units that vary considerably in thickness, slope, and hydrogeologic properties, as well as large seasonal fluctuations of the groundwater table and flow rates. Other significant factors are local recharge from leaking underground storm drains and recharge from steep uphill areas. The zonation method was employed to account for the clustering of high and low hydraulic conductivities measured in a geologic unit. A composite model was used to represent the bulk effect of thin layers of relatively high hydraulic conductivity found within bedrock of otherwise low conductivity. The inverse simulator ITOUGH2 was used to calibrate the model for the distribution of rock properties. The model was initially calibrated using data collected between 1994 and 1996. To check the validity of the model, it was subsequently applied to predicting groundwater level fluctuation and groundwater flux between 1996 and 1998. Comparison of simulated and measured data demonstrated that the model is capable of predicting the complex flow reasonably well. Advective transport was approximated using pathways of particles originating from source areas of the plumes. The advective transport approximation was in good agreement with the trend of contaminant plumes observed over the years. The validated model was then refined to focus on a subsection of the large system. The refined model was subsequently used to assess the efficiency of hydraulic measures implemented for remediation.

Zhou, Quanlin; Birkholzer, Jens T.; Javandel, Iraj; Jordan, Preston D.

2004-01-14T23:59:59.000Z

403

Life-Cycle Water Impacts of U.S. Transportation Fuels  

E-Print Network (OSTI)

GREET Pathway for Corn Ethanol. California Air Resourcesthat for each m 3 of corn ethanol produced in the Unitedthe water footprint of corn ethanol production will be on

Scown, Corinne Donahue

2010-01-01T23:59:59.000Z

404

Grand challenge problems in environmental modeling and remediation: Groundwater contaminant transport. Final project report 1998  

SciTech Connect

The over-reaching goal of the Groundwater Grand Challenge component of the Partnership in Computational Science (PICS) was to develop and establish the massively parallel approach for the description of groundwater flow and transport and to address the problem of uncertainties in the data and its interpretation. This necessitated the development of innovative algorithms and the implementation of massively parallel computational tools to provide a suite of simulators for groundwater flow and transport in heterogeneous media. This report summarizes the activities and deliverables of the Groundwater Grand Challenge project funded through the High Performance Computing grand challenge program of the Department of Energy from 1995 through 1997.

NONE

1998-04-01T23:59:59.000Z

405

Landauer transport model for Hawking radiation from a Reissner-Nordstrom black hole  

E-Print Network (OSTI)

The recent work of Nation et al in which Hawking radiation energy and entropy flow from a black hole can be regarded as a one-dimensional (1D) Landauer transport process is extended to the case of a Reissner-Nordstrom (RN) black hole. It is found that the flow of charge current can also be transported via a 1D quantum channel except the current of Hawking radiation. The maximum entropy current, which is shown to be particle statistics independence, is also obtained.

Xiao-Xiong Zeng; Shi-Wei Zhou; Wen-Biao Liu

2011-06-03T23:59:59.000Z

406

Regional groundwater flow and tritium transport modeling and risk assessment of the underground test area, Nevada Test Site, Nevada  

Science Conference Proceedings (OSTI)

The groundwater flow system of the Nevada Test Site and surrounding region was evaluated to estimate the highest potential current and near-term risk to the public and the environment from groundwater contamination downgradient of the underground nuclear testing areas. The highest, or greatest, potential risk is estimated by assuming that several unusually rapid transport pathways as well as public and environmental exposures all occur simultaneously. These conservative assumptions may cause risks to be significantly overestimated. However, such a deliberate, conservative approach ensures that public health and environmental risks are not underestimated and allows prioritization of future work to minimize potential risks. Historical underground nuclear testing activities, particularly detonations near or below the water table, have contaminated groundwater near testing locations with radioactive and nonradioactive constituents. Tritium was selected as the contaminant of primary concern for this phase of the project because it is abundant, highly mobile, and represents the most significant contributor to the potential radiation dose to humans for the short term. It was also assumed that the predicted risk to human health and the environment from tritium exposure would reasonably represent the risk from other, less mobile radionuclides within the same time frame. Other contaminants will be investigated at a later date. Existing and newly collected hydrogeologic data were compiled for a large area of southern Nevada and California, encompassing the Nevada Test Site regional groundwater flow system. These data were used to develop numerical groundwater flow and tritium transport models for use in the prediction of tritium concentrations at hypothetical human and ecological receptor locations for a 200-year time frame. A numerical, steady-state regional groundwater flow model was developed to serve as the basis for the prediction of the movement of tritium from the underground testing areas on a regional scale. The groundwater flow model was used in conjunction with a particle-tracking code to define the pathlines followed by groundwater particles originating from 415 points associated with 253 nuclear test locations. Three of the most rapid pathlines were selected for transport simulations. These pathlines are associated with three nuclear test locations, each representing one of the three largest testing areas. These testing locations are: BOURBON on Yucca Flat, HOUSTON on Central Pahute Mesa, and TYBO on Western Pahute Mesa. One-dimensional stochastic tritium transport simulations were performed for the three pathlines using the Monte Carlo method with Latin hypercube sampling. For the BOURBON and TYBO pathlines, sources of tritium from other tests located along the same pathline were included in the simulations. Sensitivity analyses were also performed on the transport model to evaluate the uncertainties associated with the geologic model, the rates of groundwater flow, the tritium source, and the transport parameters. Tritium concentration predictions were found to be mostly sensitive to the regional geology in controlling the horizontal and vertical position of transport pathways. The simulated concentrations are also sensitive to matrix diffusion, an important mechanism governing the migration of tritium in fractured carbonate and volcanic rocks. Source term concentration uncertainty is most important near the test locations and decreases in importance as the travel distance increases. The uncertainty on groundwater flow rates is as important as that on matrix diffusion at downgradient locations. The risk assessment was performed to provide conservative and bounding estimates of the potential risks to human health and the environment from tritium in groundwater. Risk models were designed by coupling scenario-specific tritium intake with tritium dose models and cancer and genetic risk estimates using the Monte Carlo method. Estimated radiation doses received by individuals from chronic exposure to tritium, and the corre

None

1997-10-01T23:59:59.000Z

407

Development of a physically-based model for transport of Cryptosporidium parvum in overland flow  

Science Conference Proceedings (OSTI)

Surface runoff from animal production facilities contains numerous microbial pathogens which pose a direct health hazard to both humans and animals. In order to preserve safe water resources and sustainable agriculture by reducing runoff-mediated contamination ... Keywords: Flow, Hydrology, Pathogen, Transport, Watersheds

R. Bhattarai; P. Kalita; J. Trask; M. S. Kuhlenschmidt

2011-11-01T23:59:59.000Z

408

Charge transport through bio-molecular wires in a solvent: Bridging molecular dynamics and model Hamiltonian approaches  

E-Print Network (OSTI)

We present a hybrid method based on a combination of quantum/classical molecular dynamics (MD) simulations and a mod el Hamiltonian approach to describe charge transport through bio-molecular wires with variable lengths in presence o f a solvent. The core of our approach consists in a mapping of the bio-molecular electronic structure, as obtained f rom density-functional based tight-binding calculations of molecular structures along MD trajectories, onto a low di mensional model Hamiltonian including the coupling to a dissipative bosonic environment. The latter encodes fluctuat ion effects arising from the solvent and from the molecular conformational dynamics. We apply this approach to the c ase of pG-pC and pA-pT DNA oligomers as paradigmatic cases and show that the DNA conformational fluctuations are essential in determining and supporting charge transport.

R. Gutierrez; R. Caetano; P. B. Woiczikowski; T. Kubar; M. Elstner; G. Cuniberti

2009-01-22T23:59:59.000Z

409

Modeling most likely pathways for smuggling radioactive and special nuclear materials on a worldwide multi-modal transportation network  

Science Conference Proceedings (OSTI)

Nuclear weapons proliferation is an existing and growing worldwide problem. To help with devising strategies and supporting decisions to interdict the transport of nuclear material, we developed the Pathway Analysis, Threat Response and Interdiction Options Tool (PATRIOT) that provides an analytical approach for evaluating the probability that an adversary smuggling radioactive or special nuclear material will be detected during transit. We incorporate a global, multi-modal transportation network, explicit representation of designed and serendipitous detection opportunities, and multiple threat devices, material types, and shielding levels. This paper presents the general structure of PATRIOT, all focuses on the theoretical framework used to model the reliabilities of all network components that are used to predict the most likely pathways to the target.

Saeger, Kevin J [Los Alamos National Laboratory; Cuellar, Leticia [Los Alamos National Laboratory

2010-10-28T23:59:59.000Z

410

Modeling most likely pathways for smuggling radioactive and special nuclear materials on a worldwide multimodal transportation network  

Science Conference Proceedings (OSTI)

Nuclear weapons proliferation is an existing and growing worldwide problem. To help with devising strategies and supporting decisions to interdict the transport of nuclear material, we developed the Pathway Analysis, Threat Response and Interdiction Options Tool (PATRIOT) that provides an analytical approach for evaluating the probability that an adversary smuggling radioactive or special nuclear material will be detected during transit. We incorporate a global, multi-modal transportation network, explicit representation of designed and serendipitous detection opportunities, and multiple threat devices, material types, and shielding levels. This paper presents the general structure of PATRIOT, and focuses on the theoretical framework used to model the reliabilities of all network components that are used to predict the most likely pathways to the target.

Saeger, Kevin J [Los Alamos National Laboratory; Cuellar, Leticia [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

411

Using laboratory flow experiments and reactive chemical transport modeling for designing waterflooding of the Agua Fria Reservoir, Poza Rica-Altamira Field, Mexico  

E-Print Network (OSTI)

transport modeling of injection well scaling and acidizingrecovery program. U S A M Injection well Observation wellFig. 1Location of 5 injection wells and 18 monitoring wells

Birkle, P.

2009-01-01T23:59:59.000Z

412

Analysis of Convective Transport and Parameter Sensitivity in a Single Column Version of the Goddard Earth Observation System, Version 5, General Circulation Model  

Science Conference Proceedings (OSTI)

Convection strongly influences the distribution of atmospheric trace gases. General circulation models (GCMs) use convective mass fluxes calculated by parameterizations to transport gases, but the results are difficult to compare with trace gas ...

L. E. Ott; J. Bacmeister; S. Pawson; K. Pickering; G. Stenchikov; M. Suarez; H. Huntrieser; M. Loewenstein; J. Lopez; I. Xueref-Remy

2009-03-01T23:59:59.000Z

413

Southward Eddy Heat Transport Occurring along Southern Flanks of the Kuroshio Extension and the Gulf Stream in a 1/10 Global Ocean General Circulation Model  

Science Conference Proceedings (OSTI)

The present study investigates meridional heat transport induced by oceanic mesoscale variability in the World Ocean using a 1/10 global Ocean General Circulation Model (OGCM) running on the Earth Simulator. The results indicate prominent ...

Kunihiro Aoki; Shoshiro Minobe; Youichi Tanimoto; Yoshikazu Sasai

414

Introducing a Partitioning Mechanism for PAHs into the Community Multiscale Air Quality Modeling System and Its Application to Simulating the Transport of Benzo(a)pyrene over Europe  

Science Conference Proceedings (OSTI)

Into the Community Multiscale Air Quality modeling system (CMAQ) that is widely used for simulating the transport and fate of air pollutants, a new module was inserted that accounts for the partitioning of semivolatile organic compoundsin ...

Armin Aulinger; Volker Matthias; Markus Quante

2007-11-01T23:59:59.000Z

415

Use of the CAPTEX Data for Evaluations of a Long-Range Transport Numerical Model with a Four-Dimensional Data Assimilation Technique  

Science Conference Proceedings (OSTI)

A four-dimensional data assimilation technique is employed in a time-dependent, three-dimensional mesoscale model to simulate long-range pollutant transport and diffusion in the eastern United States using the 1983 Cross-Appalachian Tracer ...

Chih-Yue Jim Kao; Tetsuji Yamada

1988-02-01T23:59:59.000Z

416

User Guide for the GREET Fleet Footprint Calculator 1.0 Beginning in 1998, the Department of Energy's (DOE's) Clean Cities Program enlisted expertise  

E-Print Network (OSTI)

Gas (LNG) Landfill Gas (LFG) Liquifed Petroleum Gas/ Propane (LPG) Electricity Gaseous Hydrogen (G.H2 in accordance with the desire to measure the petroleum displacement and greenhouse gas (GHG) emissions of medium represents the vehicle's operation activities. It is important to examine transportation fuels

Argonne National Laboratory

417

Modeling Tritium Transport in PbLi Breeder Blankets Under Steady State  

SciTech Connect

Tritium behavior in the breeder/coolant plays a crucial role in keeping the tritium loss under an allowable limit and realizing high tritium recovery efficiency. In this paper, progress toward the development of a comprehensive 3D predictive capability is discussed and presented. The sequence of transport processes leading to tritium release includes diffusion and convection through the PbLi, transfer across the liquid/solid interface, diffusion of atomic tritium through the structure, and dissolution-recombination at the solid/gas interface. Numerical simulation of the coupled individual physics phenomena of tritium transport is performed for DCLL/HCLL type breeder blankets under realistic reactor-like conditions in this paper. Tritium concentration and permeation are presented and the MHD effects are evaluated. Preliminary results shows that the MHD velocity profile has the significant effect in preventing tritium permeation due to the higher convection effects near the wall.

H. Zhang; A. Ying; M. Abdou; B. Merrill

2011-08-01T23:59:59.000Z

418

HydroTrend v.3.0: A climate-driven hydrological transport model that simulates discharge and sediment load leaving a river system  

Science Conference Proceedings (OSTI)

HydroTrend v.3.0 is a climate-driven hydrological water balance and transport model that simulates water discharge and sediment load at a river outlet, by incorporating drainage basin properties (river networks, hypsometry, relief, reservoirs) together ... Keywords: Human impacts, Modeling distributary channels, River model, Sediment concentration, Sediment discharge

Albert J. Kettner; James P. M. Syvitski

2008-10-01T23:59:59.000Z

419

Visualization of a Deterministic Radiation Transport Model Using Standard Visualization Tools  

SciTech Connect

Output from a deterministic radiation transport code running on a CRAY SV1 is imported into a standard distributed, parallel, visualization tool for analysis. Standard output files, consisting of tetrahedral meshes, are imported to the visualization tool through the creation of a application specific plug-in module. Visualization samples are included, providing visualization of steady state results. Different plot types and operators are utilized to enhance the analysis and assist in reporting the results of the analysis.

James A. Galbraith; L. Eric Greenwade

2004-05-01T23:59:59.000Z

420

A model to assess the relative impact of policy in transportation energy expenditures  

Science Conference Proceedings (OSTI)

The research reported in this paper uses the 1977 and 1983 Nationwide Personal Transportation Study surveys (NPTS's) to estimate the cross-section and time responses of minority and majority households in terms of variations in vehicles held by the household, VMT per household vehicle, 1983 dollar income of the household, education and age of the household head, transit availability to the household, workers and nonworkers per household, and urban vs rural location.

Santini, D.J.; Vyas, A.D.

1987-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "transportation greet model" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Modeling heat and mass transport phenomena at higher temperatures in solar distillation systems - The Chilton-Colburn analogy  

Science Conference Proceedings (OSTI)

In the present investigation efforts have been devoted towards developing an analysis suitable for heat and mass transfer processes modeling in solar distillation systems, when they are operating at higher temperatures. For this purpose the use of Lewis relation is not new although its validity is based on the assumptions of identical boundary layer concentration and temperature distributions, as well as low mass flux conditions, which are not usually met in solar distillation systems operating at higher temperatures associated with considerable mass transfer rates. The present analysis, taking into consideration these conditions and the temperature dependence of all pertinent thermophysical properties of the saturated binary mixture of water vapor and dry air, leads to the development of an improved predictive accuracy model. This model, having undergone successful first order validation against earlier reported measurements from the literature, appears to offer more accurate predictions of the transport processes and mass flow rate yield of solar stills when operated at elevated temperatures. (author)

Tsilingiris, P.T. [Department of Energy Engineering, Heat Transfer Laboratory, Technological Education Institution of Athens, A. Spyridonos Street, GR 122 10 Egaleo, Athens (Greece)

2010-02-15T23:59:59.000Z

422

Multiphase Reactive Transport modeling of Stable Isotope Fractionation of Infiltrating Unsaturated Zone Pore Water and Vapor Using TOUGHREACT  

Science Conference Proceedings (OSTI)

Numerical simulations of transport and isotope fractionation provide a method to quantitatively interpret vadose zone pore water stable isotope depth profiles based on soil properties, climatic conditions, and infiltration. We incorporate the temperature-dependent equilibration of stable isotopic species between water and water vapor, and their differing diffusive transport properties into the thermodynamic database of the reactive transport code TOUGHREACT. These simulations are used to illustrate the evolution of stable isotope profiles in semiarid regions where recharge during wet seasons disturbs the drying profile traditionally associated with vadose zone pore waters. Alternating wet and dry seasons lead to annual fluctuations in moisture content, capillary pressure, and stable isotope compositions in the vadose zone. Periodic infiltration models capture the effects of seasonal increases in precipitation and predict stable isotope profiles that are distinct from those observed under drying (zero infiltration) conditions. After infiltration, evaporation causes a shift to higher 18O and D values, which are preserved in the deeper pore waters. The magnitude of the isotopic composition shift preserved in deep vadose zone pore waters varies inversely with the rate of infiltration.

Singleton, Michael J.; Sonnenthal, Eric L.; Conrad, Mark E.; DePaolo, Donald J.

2003-08-28T23:59:59.000Z

423

Transportation Routing Analysis Geographic Information System (TRAGIS)  

E-Print Network (OSTI)

Transportation Routing Analysis Geographic Information System (TRAGIS) Model and Network Databases The Transportation Routing Analysis Geographic Information System (TRAGIS) model is a geographic information system tool for modeling transportation routing. TRAGIS offers numerous options for route calculation

424

A Hybrid Cellular Automaton Model of Solid Tumor Growth and Bioreductive Drug Transport  

Science Conference Proceedings (OSTI)

Bioreductive drugs are a class of hypoxia selective drugs that are designed to eradicate the hypoxic fraction of solid tumors. Their activity depends upon a number of biological and pharmacological factors and we used a mathematical modeling approach ... Keywords: Tumors,Biological system modeling,Drugs,Mathematical model,Electronic countermeasures,Computational modeling,Solids,microenvironment and Tirapazamine,Extra cellular matrix,Hypoxia,mathematical modeling

N. Kazmi; M. A. Hossain; R. M. Phillips

2012-11-01T23:59:59.000Z

425

Basing Transport Planning on Principles of Social Justice  

E-Print Network (OSTI)

M. Frost, et al. (2000). Transport and Social Exclusion inG. Willumsen. (1994). Modelling Transport. Chichester: JohnG. Willumsen. (2001). Modelling Transport. Chichester: John

Martens, Karel

2006-01-01T23:59:59.000Z

426

A unified numerical framework model for simulating flow, transport, and heat transfer in porous and fractured media  

E-Print Network (OSTI)

Flow, Transport, and Heat Transfer in Porous and Fracturedtransport, and heat transfer in porous and fracturedflow, chemical transport, and heat transfer in rock. These

Wu, Yu-Shu

2004-01-01T23:59:59.000Z

427

A unified numerical framework model for simulating flow, transport, and heat transfer in porous and fractured media  

E-Print Network (OSTI)

transport, and heat transfer processes in porous media. 2.1.mass transport, and heat-transfer processes through porousinvolved. These heat-transfer processes are complicated by

Wu, Yu-Shu

2004-01-01T23:59:59.000Z

428

Preliminary testing of turbulence and radionuclide transport modeling in deep ocean environment  

Science Conference Proceedings (OSTI)

Pacific Northwest Laboratory (PNL) performed a study for the US Environmental Protection Agency's Office of Radiation Programs to (1) identify candidate models for regional modeling of low-level waste ocean disposal sites in the mid-Atlantic ocean; (2) evaluate mathematical representation of the model's eddy viscosity/dispersion coefficients; and (3) evaluate the adequacy of the k-{epsilon} turbulence model and the feasibility of one of the candidate models, TEMPEST{copyright}/FLESCOT{copyright}, to deep-ocean applications on a preliminary basis. PNL identified the TEMPEST{copyright}/FLESCOT{copyright}, FLOWER, Blumberg's, and RMA 10 models as appropriate candidates for the regional radionuclide modeling. Among these models, TEMPEST/FLESCOT is currently the only model that solves distributions of flow, turbulence (with the k-{epsilon} model), salinity, water temperature, sediment, dissolved contaminants, and sediment-sorbed contaminants. Solving the Navier-Stokes equations using higher order correlations is not practical for regional modeling because of the prohibitive computational requirements; therefore, the turbulence modeling is a more practical approach. PNL applied the three-dimensional code, TEMPEST{copyright}/FLESCOT{copyright} with the k-{epsilon} model, to a very simple, hypothetical, two-dimensional, deep-ocean case, producing at least qualitatively appropriate results. However, more detailed testing should be performed for the further testing of the code. 46 refs., 39 figs., 6 tabs.

Onishi, Y.; Dummuller, D.C.; Trent, D.S. (Pacific Northwest Lab., Richland, WA (USA); Washington State Univ., Pullman, WA (USA); Pacific Northwest Lab., Richland, WA (USA))

1989-03-01T23:59:59.000Z

429

Heavy Duty Diesel Particulate Matter and Fuel Consumption Modeling for Transportation Analysis  

E-Print Network (OSTI)

fuel use. Mesoscale Modeling Data Set and Mesoscale Modelobserved, quantified in the data set, and modeled to improveerrors for the validation data set are less than 2% for fuel

Scora, George Alexander

2011-01-01T23:59:59.000Z

430

Modeling Unsaturated Flow and Transport Processes in Fractured Tuffs of Yucca Mountain  

E-Print Network (OSTI)

zone site-scale model, Yucca Mountain Site Characterizationsite-scale model, Yucca Mountain Project Milestone 3GLM105M,unsaturated zone, Yucca Mountain, Nevada. Water-Resources

Wu, Yu-Shu; Lu, Guoping; Zhang, Keni; Bodvarsson, G.S.

2003-01-01T23:59:59.000Z

431

Application of Snowfall and Wind Statistics to Snow Transport Modeling for Snowdrift Control in Minnesota  

Science Conference Proceedings (OSTI)

Models were utilized to determine the snow accumulation season (SAS) and to quantify windblown snow for the purpose of snowdrift control for locations in Minnesota. The models require mean monthly temperature, snowfall, density of snow, and wind ...

Martha D. Shulski; Mark W. Seeley

2004-11-01T23:59:59.000Z

432

The Role of Wave Breaking, Linear Instability, and PV Transports in Model Block Onset  

Science Conference Proceedings (OSTI)

To understand mechanisms responsible for the onset of atmospheric blocks, the authors study model blocks that form in a two-layer isentropic primitive equation model. The latter includes diabatic heating, parameterized as a Newtonian relaxation ...

Manuel S. F. V. de Pondeca; Albert Barcilon; Xiaolei Zou

1998-09-01T23:59:59.000Z

433

Interannual Variability of Meridional Heat Transport in a Numerical Model of the Upper Equatorial Pacific ocean  

Science Conference Proceedings (OSTI)

The interannual heat budget of the Pacific equatorial upwelling zone is studied using a primitive equation, a reduced gravity model of the upper Pacific equatorial ocean. The model is forced with monthly mean FSU winds from 1971 to 1990. A ...

Esther C. Brady

1994-12-01T23:59:59.000Z

434

AN ANALYTICAL MODEL FOR FISSION-PRODUCT TRANSPORT AND DEPOSITION FROM GAS STREAMS  

SciTech Connect

An important mechanism in the transport and deposition of very small particles from gas streams to the surfaces of a conduit is diffusion due to the Brownian movement of particles. The heat-mass analogy is used to describe the diffusion, and equations are derived for the deposition of fission products from a gas stream to wall surfaces as a function of the distance along the conduit. Effects of radioactive decay on the validity of the heat-mass analogy in applying standard heat transfer relations to predict material transfer to wall surfaces are discussed. (auth)

Ozisik, M. N.

1963-08-01T23:59:59.000Z

435

A groundwater flow and transport model of long-term radionuclide migration in central Frenchman flat, Nevada test site  

Science Conference Proceedings (OSTI)

A set of groundwater flow and transport models were created for the Central Testing Area of Frenchman Flat at the former Nevada Test Site to investigate the long-term consequences of a radionuclide migration experiment that was done between 1975 and 1990. In this experiment, radionuclide migration was induced from a small nuclear test conducted below the water table by pumping a well 91 m away. After radionuclides arrived at the pumping well, the contaminated effluent was discharged to an unlined ditch leading to a playa where it was expected to evaporate. However, recent data from a well near the ditch and results from detailed models of the experiment by LLNL personnel have convincingly demonstrated that radionuclides from the ditch eventually reached the water table some 220 m below land surface. The models presented in this paper combine aspects of these detailed models with concepts of basin-scale flow to estimate the likely extent of contamination resulting from this experiment over the next 1,000 years. The models demonstrate that because regulatory limits for radionuclide concentrations are exceeded only by tritium and the half-life of tritium is relatively short (12.3 years), the maximum extent of contaminated groundwater has or will soon be reached, after which time the contaminated plume will begin to shrink because of radioactive decay. The models also show that past and future groundwater pumping from water supply wells within Frenchman Flat basin will have negligible effects on the extent of the plume.

Kwicklis, Edward Michael [Los Alamos National Laboratory; Becker, Naomi M [Los Alamos National Laboratory; Ruskauff, Gregory [NAVARRO-INTERA, LLC.; De Novio, Nicole [GOLDER AND ASSOC.; Wilborn, Bill [US DOE NNSA NSO

2010-11-10T23:59:59.000Z

436

Modeling of Groundwater Flow and Radionuclide Transport at the Climax Mine sub-CAU, Nevada Test Site  

SciTech Connect

The Yucca Flat-Climax Mine Corrective Action Unit (CAU) on the Nevada Test Site comprises 747 underground nuclear detonations, all but three of which were conducted in alluvial, volcanic, and carbonate rocks in Yucca Flat. The remaining three tests were conducted in the very different hydrogeologic setting of the Climax Mine granite stock located in Area 15 at the northern end of Yucca Flat. As part of the Corrective Action Investigation (CAI) for the Yucca Flat-Climax Mine CAU, models of groundwater flow and radionuclide transport will be developed for Yucca Flat. However, two aspects of these CAU-scale models require focused modeling at the northern end of Yucca Flat beyond the capability of these large models. First, boundary conditions and boundary flows along the northern reaches of the Yucca Flat-Climax Mine CAU require evaluation to a higher level of detail than the CAU-scale Yucca Flat model can efficiently provide. Second, radionuclide fluxes from the Climax tests require analysis of flow and transport in fractured granite, a unique hydrologic environment as compared to Yucca Flat proper. This report describes the Climax Mine sub-CAU modeling studies conducted to address these issues, with the results providing a direct feed into the CAI for the Yucca Flat-Climax Mine CAU. Three underground nuclear detonations were conducted for weapons effects testing in the Climax stock between 1962 and 1966: Hard Hat, Pile Driver, and Tiny Tot. Though there is uncertainty regarding the position of the water table in the stock, it is likely that all three tests were conducted in the unsaturated zone. In the early 1980s, the Spent Fuel Test-Climax (SFT-C) was constructed to evaluate the feasibility of retrievable, deep geologic storage of commercial nuclear reactor wastes. Detailed mapping of fractures and faults carried out for the SFT-C studies greatly expanded earlier data sets collected in association with the nuclear tests and provided invaluable information for subsequent modeling studies at Climax. The objectives of the Climax Mine sub-CAU work are to (1) provide simulated heads and groundwater flows for the northern boundaries of the Yucca Flat-Climax Mine CAU model, while incorporating alternative conceptualizations of the hydrogeologic system with their associated uncertainty, and (2) provide radionuclide fluxes from the three tests in the Climax stock using modeling techniques that account for groundwater flow in fractured granite. Meeting these two objectives required two different model scales. The northern boundary groundwater fluxes were addressed using the Death Valley Regional Flow System (DVRFS) model (Belcher, 2004) developed by the U.S. Geological Survey as a modeling framework, with refined hydrostratigraphy in a zone north of Yucca Flat and including Climax stock. Radionuclide transport was simulated using a separate model confined to the granite stock itself, but linked to regional groundwater flow through boundary conditions and calibration targets.

K. Pohlmann; M. Ye; D. Reeves; M. Zavarin; D. Decker; J. Chapman

2007-09-28T23:59:59.000Z

437

Grand Challenge Problems in Environmental Modeling and Remediation: Groundwater Contaminant Transport (Partnerships in Computational Science)  

SciTech Connect

The over-reaching goal of the Groundwater Grand Challenge component of the Partnership in Computational Science (PICS) was to develop and establish the massively parallel approach for the description of groundwater flow and transport and to address the problem of uncertainties in the data and its interpretation. This necessitated the development of innovative algorithms and the implementation of massively parallel computational tools to provide a suite of simulators for groundwater flow and transport in heterogeneous media. This report summarizes the activities and deliverables of the University of South Carolina component of the Groundwater Grand Challenge project funded through the High Performance Computing grand challenge program of the Department of Energy from 1995 through 1997. Seven institutions were primarily involved in this project: Brookhaven National Laboratory, Oak Ridge National Laboratory, Princeton University, SUNY at Stony Brook, Texas A&M University, The University of South Carolina, and the University of Texas at Austin, with contributing efforts from the Westinghouse Savannah River Technology Center. Each institution had primary responsibility for specific research components, but strong collaboration among all institutions was essential for the success of the project and in producing the final deliverables. PICS deliverables include source code for the suite of research simulators and auxiliary HPC tools, associated documentation, and test problems. These materials will be available as indicated from each institution's web page or from the Center for Computational Sciences Oak Ridge National Laboratory in January 1998.

Sharpley, Robert C.

1997-12-01T23:59:59.000Z

438

Subsurface Pathway Flow and Transport Modeling for the Idaho National Engineering and Environmental Laboratory's Subsurface Disposal Area  

SciTech Connect

Migration of contaminants through the complex subsurface at the Idaho National Engineering and Environmental Laboratory's Subsurface Disposal Area was simulated for an ongoing Comprehensive Environmental Response, Compensation, and Liability (CERCLA) assessment. A previously existing model for simulating flow and transport through the vadose zone for this site was updated to incorporate information obtained from recent characterization activities. Given the complexity of the subsurface at this site, the simulation results were acknowledged to be uncertain. Rather than attempt parametric approaches to quantify uncertainty, it was recognized that conceptual uncertainty involving the controlling processes was likely dominant. So, the effort focused on modeling different scenarios to evaluate the impact of the conceptual uncertainty.

Magnuson, S.O.

2002-05-10T23:59:59.000Z

439

Reaction-based Transport Modeling of Iron Reduction and Uranium Immobilization at Area 2 of the NABIR Field Research Center  

Science Conference Proceedings (OSTI)

This research sought to examine biogeochemical processes likely to take place in the less conductive materials above and below the gravel during the in situ ethanol biostimulation experiment conducted at Area 2 during 2005-2006. The in situ experiment in turn examined the hypothesis that injection of electron donor into this layer would induce formation of a redox barrier in the less conductive materials, resulting in decreased mass transfer of uranium out these materials and attendant declines in groundwater U(VI) concentration. Our project focuses on the development of a mechanistic understanding and quantitative models of coupled Fe(III)/U(VI) reduction in FRC Area 2 sediments. This report summarizes research activities conducted at The University of Central Florida (2004-2007), the development of biogeochemical and reactive transport models and the conduction of numerical simulations at laboratory, column, and field scales.

Tsyh Yeh, Gour

2007-12-21T23:59:59.000Z

440

Sustainable Transport  

E-Print Network (OSTI)

THOUGHT PIECE Sustainable Transport by Melvin M. Webberwant to sustain any mode of transport only if we judge it todraconian in rejecting transport modes that have failed in

Webber, Melvin

2006-01-01T23:59:59.000Z

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441

Development of Alternate Soil Clean-Up Goals for Hanford Waste Sites Using Fate and Transport Modeling  

SciTech Connect

Remedial Action Goals (RAGs) for soil contaminant levels that are protective of groundwater have been determined for the Removal/Treatment/Disposal (RTD) sites at the 200-UW-1 Operable Unit on the Hanford Site. The RAG values were determined using a methodology involving the back-calculation of soil contaminant levels protective of groundwater (i.e., resulting groundwater concentrations are {<=} MCLs) in conjunction with the fate and transport modeling as a risk-based alternative to the currently prescribed use of background or detection limit default values. This methodology is important for waste management activities at the Hanford Site because it provides risk-based metrics and a technical basis for determining the levels of contamination 'left in place' in the Hanford Site vadose zone that are protective of human health and the environment. The methodology and the use of fate and transport modeling described here comply with federal guidelines for the use of environmental models. This approach is also consistent with one of several allowable methods identified in State guidelines for deriving soil concentrations for ground water protection. Federal and state guidelines recommend the use of site-specific information and data in risk-based assessments of risk and/or protectiveness. The site-specific characteristics of the Hanford Site, which include consideration of the semi-arid climate, an unsaturated zone thickness of over 80 m (262 feet), and associated/other site features and processes, are integral for the risk-based assessments associated with the protection of groundwater pathway. This methodology yields soil cleanup values (RAGs) for the 200-UW-1 OU waste sites selected for the removal/treatment/disposal (RTD) remedy. These proposed RAGs for uranium, nitrate, and technetium-99 are derived from soil concentrations calculated not to cause contamination of groundwater at levels that exceed the ground water MCLs, and are 40 to 200 times greater than currently prescribed default values. The proposed RAG soil concentration values derive from the results of the fate and transport modeling for a reference volume of contaminated soil extending to a depth of 15 feet, and also for a depth extending from 15 feet to 30 feet. The site-specific parameters for the 200-UW-1 OU RTD waste sites used to calculate the proposed RAG values, and the fate and transport modeling are also described. The assessment of uncertainties, assumptions, and model limitations indicate that the model is capable of adequately representing the Hanford vadose zone system and that the estimated soil cleanup levels are conservatively biased toward over-estimation of groundwater impacts. The risk-based metrics provided by this methodology can potentially greatly reduce the amount of excavation needed at the hundreds of RTD waste sites, and also have significant implications for deeper vadose zone applications. These implications include an improved technical basis for remedy selection, decisions, characterization, and stakeholder communication and cost savings in the range of hundreds of millions of dollars. (authors)

Hoover, J.D. [Fluor Hanford, Inc. (United States); McMahon, W.J. [CH2M Hill Hanford Group (United States); Leary, K.D. [DOE/RL (United States)

2008-07-01T23:59:59.000Z

442

Upscaling of Long-Term U9VI) Desorption from Pore Scale Kinetics to Field-Scale Reactive Transport Models  

Science Conference Proceedings (OSTI)

Environmental systems exhibit a range of complexities which exist at a range of length and mass scales. Within the realm of radionuclide fate and transport, much work has been focused on understanding pore scale processes where complexity can be reduced to a simplified system. In describing larger scale behavior, the results from these simplified systems must be combined to create a theory of the whole. This process can be quite complex, and lead to models which lack transparency. The underlying assumption of this approach is that complex systems will exhibit complex behavior, requiring a complex system of equations to describe behavior. This assumption has never been tested. The goal of the experiments presented is to ask the question: Do increasingly complex systems show increasingly complex behavior? Three experimental tanks at the intermediate scale (Tank 1: 2.4m x 1.2m x 7.6cm, Tank 2: 2.4m x 0.61m x 7.6cm, Tank 3: 2.4m x 0.61m x 0.61m (LxHxW)) have been completed. These tanks were packed with various physical orientations of different particle sizes of a uranium contaminated sediment from a former uranium mill near Naturita, Colorado. Steady state water flow was induced across the tanks using constant head boundaries. Pore water was removed from within the flow domain through sampling ports/wells; effluent samples were also taken. Each sample was analyzed for a variety of analytes relating to the solubility and transport of uranium. Flow fields were characterized using inert tracers and direct measurements of pressure head. The results show that although there is a wide range of chemical variability within the flow domain of the tank, the effluent uranium behavior is simple enough to be described using a variety of conceptual models. Thus, although there is a wide range in variability caused by pore scale behaviors, these behaviors appear to be smoothed out as uranium is transported through the tank. This smoothing of uranium transport behavior transcends many of the physical and chemical heterogeneities added to the tank experiments.

Andy Miller

2009-01-25T23:59:59.000Z

443

Modeling of Electronic and Ionic Transport Resistances Within Lithium-Ion Battery Cathodes.  

E-Print Network (OSTI)

??In this work, a mathematical model is reported and validated, which describes the performance of porous electrodes under low and high rates of discharge. This (more)

Stephenson, David E 1983-

2008-01-01T23:59:59.000Z

444

A model of transport of fuel gases in a charring solid and its ...  

Science Conference Proceedings (OSTI)

... [6,7]. Several models of pyrolysis of charring materi- als have been developed in the past motivated either by fires or biomass pyrolysis. ...

2007-10-03T23:59:59.000Z

445

Modeling and analysis of a heat transport transient test facility for space nuclear systems.  

E-Print Network (OSTI)

??The purpose of this thesis is to design a robust test facility for a small space nuclear power system and model its physical behavior under (more)

[No author

2013-01-01T23:59:59.000Z

446

Coupled modeling of non-isothermal multiphase flow, solute transport and reactive chemistry in porous and fractured media: 1. Model Development and Validation  

E-Print Network (OSTI)

multiphase reactive transport, in Reactive transport in porousporous and fractured media under non-isothermal multiphaseporous and fractured media under non-isothermal multiphase

Xu, Tianfu; Pruess, Karsten

1998-01-01T23:59:59.000Z

447

MELCOR 1.8.5 modeling aspects of fission product release, transport and deposition an assessment with recommendations.  

Science Conference Proceedings (OSTI)

The Phebus and VERCORS data have played an important role in contemporary understanding and modeling of fission product release and transport from damaged light water reactor fuel. The data from these test programs have allowed improvement of MELCOR modeling of release and transport processes for both low enrichment uranium fuel as well as high burnup and mixed oxide (MOX) fuels. This paper discusses the synthesis of these findings in the MELCOR severe accident code. Based on recent assessments of MELCOR 1.8.5 fission product release modeling against the Phebus FPT-1 test and on observations from the ISP-46 exercise, modifications to the default MELCOR 1.8.5 release models are recommended. The assessments identified an alternative set of Booth diffusion parameters recommended by ORNL (ORNL-Booth), which produced significantly improved release predictions for cesium and other fission product groups. Some adjustments to the scaling factors in the ORNL-Booth model were made for selected fission product groups, including UO{sub 2}, Mo and Ru in order to obtain better comparisons with the FPT-1 data. The adjusted model, referred to as 'Modified ORNL-Booth,' was subsequently compared to original ORNL VI fission product release experiments and to more recently performed French VERCORS tests, and the comparisons was as favorable or better than the original CORSOR-M MELCOR default release model. These modified ORNL-Booth parameters, input to MELCOR 1.8.5 as 'sensitivity coefficients' (i.e. user input that over-rides the code defaults) are recommended for the interim period until improved release models can be implemented into MELCOR. For the case of ruthenium release in air-oxidizing conditions, some additional modifications to the Ru class vapor pressure are recommended based on estimates of the RuO{sub 2} vapor pressure over mildly hyperstoichiometric UO{sub 2}. The increased vapor pressure for this class significantly increases the net transport of Ru from the fuel to the gas stream. A formal model is needed. Deposition patterns in the Phebus FPT-1 circuit were also significantly improved by using the modified ORNL-Booth parameters, where retention of lower volatile Cs{sub 2}MoO{sub 4} is now predicted in the heated exit regions of the FPT-1 test, bringing down depositions in the FPT-1 steam generator tube to be in closer alignment with the experimental data. This improvement in 'RCS' deposition behavior preserves the overall correct release of cesium to the containment that was observed even with the default CORSOR-M model. Not correctly treated however is the release and transport of Ag to the FPT-1 containment. A model for Ag release from control rods is presently not available in MELCOR. Lack of this model is thought to be responsible for the underprediction by a factor of two of the total aerosol mass to the FPT-1 containment. It is suggested that this underprediction of airborne mass led to an underprediction of the aerosol agglomeration rate. Underprediction of the agglomeration rate leads to low predictions of the aerosol particle size in comparison to experimentally measured ones. Small particle size leads low predictions of the gravitational settling rate relative to the experimental data. This error, however, is a conservative one in that too-low settling rate would result in a larger source term to the environment. Implementation of an interim Ag release model is currently under study. In the course of this assessment, a review of MELCOR release models was performed and led to the identification of several areas for future improvements to MELCOR. These include upgrading the Booth release model to account for changes in local oxidizing/reducing conditions and including a fuel oxidation model to accommodate effects of fuel stoichiometry. Models such as implemented in the French ELSA code and described by Lewis are considered appropriate for MELCOR. A model for ruthenium release under air oxidizing conditions is also needed and should be included as part of a fuel oxidation model since fuel stoichiometry is a fundamen

Gauntt, Randall O.

2010-04-01T23:59:59.000Z

448

Using toughreact to model reactive fluid flow and geochemical transport in hydrothermal systems  

DOE Green Energy (OSTI)

The interaction between hydrothermal fluids and the rocks through which they migrate alters the earlier formed primary minerals and leads to the formation of secondary minerals, resulting in changes in the physical and chemical properties of the system. We have developed a comprehensive numerical simulator, TOUGHREACT, which considers nonisothermal multi-component chemical transport in both liquid and gas phases. A variety of subsurface thermo-physical-chemical processes is considered under a wide range of conditions of pressure, temperature, water saturation, and ionic strength. The code can be applied to problems in fundamental analysis of the hydrothermal systems and in the exploration of geothermal reservoirs including chemical evolution, mineral alteration, mineral scaling, changes of porosity and permeability, and mineral recovery from geothermal fluids.

Xu, Tianfu; Sonnenthal, Eric; Spycher, Nicolas; Pruess, Karsten

2003-07-31T23:59:59.000Z

449

Single event induced charge transport modeling of GaAs MESFETs  

SciTech Connect

Previous studies examining single event charge collection in GaAs MESFETs have revealed enhanced charge collection, in which the drain charge collection can be as high as 8 times the amount of charge deposited in the device. The understanding of these charge amplifying mechanisms requires correlation between experimental and simulation analysis. Two-dimensional computer simulations of charge collection phenomena in GaAs MESFETs have been performed for alpha and laser ionization. In both cases more charge is collected than is created by the ionizing event. The simulations indicate that a bipolar transport mechanism (t < 60 ps) and a channel modulation mechanism (t > 40 ps) are responsible for this enhanced charge collection.

Weatherford, T.R.; Knudson, A.R. (SFA Inc., Landover, MD (United States)); McMorrow, D.; Campbell, A.B. (Naval Research Lab., Washington, DC (United States)); Curtice, W.R. (W.R. Curtice Consulting, Princeton Junction, NJ (United States))

1993-12-01T23:59:59.000Z

450

PAT-2 (Plutonium Air-Transportable Model 2) safety analysis report  

Science Conference Proceedings (OSTI)

The PAT-2 package is designed for the safe transport of plutonium and/or uranium in small quantities. The PAT-2 package is resistant to severe accidents, including that of a high-speed jet aircraft crash, and is designed to withstand such environments as extreme impact, crushing, puncturing and slashing loads, severe hydrocarbon-fueled fires, and deep underwater immersion, with no escape of contents. The package meets the requirements of 10 CFR 71 for Fissile Class I packages with a cargo of 15 grams of Pu-239, or other isotopic forms described herein, not to exceed 2 watts of thermal activity. This SAR presents design and oprational information including evaluations and analyses, test results, operating procedures, maintenance, and quality assurance information.

Andersen, J.A.; Davis, E.J.; Duffey, T.A.; Dupree, S.A.; George, O.L. Jr.; Ortiz, Z.

1981-07-01T23:59:59.000Z

451

Macro-System Model for Hydrogen Energy Systems Analysis in Transportation: Preprint  

DOE Green Energy (OSTI)

The Hydrogen Macro System Model (MSM) is a simulation tool that links existing and emerging hydrogen-related models to perform rapid, cross-cutting analysis. It allows analysis of the economics, primary energy-source requirements, and emissions of hydrogen production and delivery pathways.

Diakov, V.; Ruth, M.; Sa, T. J.; Goldsby, M. E.

2012-06-01T23:59:59.000Z

452

Annual Cycle of Poleward Heat Transport in the Ocean: Results from High-Resolution Modeling of the North and Equatorial Atlantic  

Science Conference Proceedings (OSTI)

The annual cycle of meridional heat transport in the North and equatorial Atlantic Ocean is studied by means of the high-resolution numerical model that had been developed in recent years as a Community Modeling Effort for the World Ocean ...

Claus W. Bning; Peter Herrmann

1994-01-01T23:59:59.000Z

453

The Atlantic Meridional Heat Transport at 26.5N and Its Relationship with the MOC in the RAPID Array and the GFDL and NCAR Coupled Models  

Science Conference Proceedings (OSTI)

The link at 26.5N between the Atlantic meridional heat transport (MHT) and the Atlantic meridional overturning circulation (MOC) is investigated in two climate models, the GFDL Climate Model version 2.1 (CM2.1) and the NCAR Community Climate ...

Rym Msadek; William E. Johns; Stephen G. Yeager; Gokhan Danabasoglu; Thomas L. Delworth; Anthony Rosati

2013-06-01T23:59:59.000Z

454

Recent Advances in Detailed Chemical Kinetic Models for Large Hydrocarbon and Biodiesel Transportation Fuels  

DOE Green Energy (OSTI)

n-Hexadecane and 2,2,4,4,6,8,8-heptamethylnonane represent the primary reference fuels for diesel that are used to determine cetane number, a measure of the ignition property of diesel fuel. With the development of chemical kinetics models for these two