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STATUS OF CHEMICAL CLEANING OF WASTE TANKS AT THE SAVANNAH RIVER SITE F TANK FARM CLOSURE PROJECT - 9114 (open access)

STATUS OF CHEMICAL CLEANING OF WASTE TANKS AT THE SAVANNAH RIVER SITE F TANK FARM CLOSURE PROJECT - 9114

Chemical Cleaning is currently in progress for Tanks 5 and 6 at the Savannah River Site. The Chemical Cleaning process is being utilized to remove the residual waste heel remaining after completion of Mechanical Sludge Removal. This work is required to prepare the tanks for closure. Tanks 5 and 6 are 1950s vintage carbon steel waste tanks that do not meet current containment standards. These tanks are 22.9 meters (75 feet) in diameter, 7.5 meters (24.5 feet) in height, and have a capacity of 2.84E+6 liters (750,000 gallons). Chemical Cleaning adds 8 wt % oxalic acid to the carbon steel tank to dissolve the remaining sludge heel. The resulting acidic waste solution is transferred to Tank 7 where it is pH adjusted to minimize corrosion of the carbon steel tank. The Chemical Cleaning flowsheet includes multiple strikes of acid in each tank. Acid is delivered by tanker truck and is added to the tanks through a hose assembly connected to a pipe penetration through the tank top. The flowsheet also includes spray washing with acid and water. This paper includes an overview of the configuration required for Chemical Cleaning, the planned flowsheet, and an overview of technical concerns associated with …
Date: December 31, 2008
Creator: Thaxton, D; Geoff Clendenen, G; Willie Gordon, W; Samuel Fink, S & Michael Poirier, M
Object Type: Article
System: The UNT Digital Library
RADIATION HEAT TRANSFER ENVIRONMENT IN FIRE AND FURNACE TESTS OF RADIOACTIVE MATERIALS PAKCAGES (open access)

RADIATION HEAT TRANSFER ENVIRONMENT IN FIRE AND FURNACE TESTS OF RADIOACTIVE MATERIALS PAKCAGES

The Hypothetical Accident Conditions (HAC) sequential test of radioactive materials packages includes a thermal test to confirm the ability of the package to withstand a transportation fire event. The test specified by the regulations (10 CFR 71) consists of a 30 minute, all engulfing, hydrocarbon fuel fire, with an average flame temperature of at least 800 C. The requirements specify an average emissivity for the fire of at least 0.9, which implies an essentially black radiation environment. Alternate test which provide equivalent total heat input at the 800 C time averaged environmental temperature may also be employed. When alternate tests methods are employed, such as furnace or gaseous fuel fires, the equivalence of the radiation environment may require justification. The effects of furnace and open confinement fire environments are compared with the regulatory fire environment, including the effects of gases resulting from decomposition of package overpack materials. The results indicate that furnace tests can produce the required radiation heat transfer environment, i.e., equivalent to the postulated pool fire. An open enclosure, with transparent (low emissivity) fire does not produce an equivalent radiation environment.
Date: December 31, 2008
Creator: Smith, A
Object Type: Article
System: The UNT Digital Library
ALUMINUM HYDRIDE: A REVERSIBLE MATERIAL FOR HYDROGEN STORAGE (open access)

ALUMINUM HYDRIDE: A REVERSIBLE MATERIAL FOR HYDROGEN STORAGE

Hydrogen storage is one of the greatest challenges for implementing the ever sought hydrogen economy. Here we report a novel cycle to reversibly form high density hydrogen storage materials such as aluminium hydride. Aluminium hydride (AlH{sub 3}, alane) has a hydrogen storage capacity of 10.1 wt% H{sub 2}, 149 kg H{sub 2}/m{sup 3} volumetric density and can be discharged at low temperatures (< 100 C). However, alane has been precluded from use in hydrogen storage systems because of the lack of practical regeneration methods; the direct hydrogenation of aluminium to form AlH{sub 3} requires over 10{sup 5} bars of hydrogen pressure at room temperature and there are no cost effective synthetic means. Here we show an unprecedented reversible cycle to form alane electrochemically, using alkali alanates (e.g. NaAlH{sub 4}, LiAlH{sub 4}) in aprotic solvents. To complete the cycle, the starting alanates can be regenerated by direct hydrogenation of the dehydrided alane and the alkali hydride being the other compound formed in the electrochemical cell. The process of forming NaAlH{sub 4} from NaH and Al is well established in both solid state and solution reactions. The use of adducting Lewis bases is an essential part of this cycle, in the isolation …
Date: December 31, 2008
Creator: Fewox, C; Ragaiy Zidan, R & Brenda Garcia-Diaz, B
Object Type: Article
System: The UNT Digital Library
Curved mesh generation and mesh refinement using Lagrangian solid mechanics (open access)

Curved mesh generation and mesh refinement using Lagrangian solid mechanics

We propose a method for generating well-shaped curved unstructured meshes using a nonlinear elasticity analogy. The geometry of the domain to be meshed is represented as an elastic solid. The undeformed geometry is the initial mesh of linear triangular or tetrahedral elements. The external loading results from prescribing a boundary displacement to be that of the curved geometry, and the final configuration is determined by solving for the equilibrium configuration. The deformations are represented using piecewise polynomials within each element of the original mesh. When the mesh is sufficiently fine to resolve the solid deformation, this method guarantees non-intersecting elements even for highly distorted or anisotropic initial meshes. We describe the method and the solution procedures, and we show a number of examples of two and three dimensional simplex meshes with curved boundaries. We also demonstrate how to use the technique for local refinement of non-curved meshes in the presence of curved boundaries.
Date: December 31, 2008
Creator: Persson, P.-O. & Peraire, J.
Object Type: Article
System: The UNT Digital Library
MEASUREMENT AND CALCULATION OF RADIONUCLIDE ACTIVITIES IN SAVANNAH RIVER SITE HIGH LEVEL WASTE SLUDGE FOR ACCEPTANCE OF DEFENSE WASTE PROCESSING FACILITY GLASS IN A FEDERAL REPOSITORY (open access)

MEASUREMENT AND CALCULATION OF RADIONUCLIDE ACTIVITIES IN SAVANNAH RIVER SITE HIGH LEVEL WASTE SLUDGE FOR ACCEPTANCE OF DEFENSE WASTE PROCESSING FACILITY GLASS IN A FEDERAL REPOSITORY

This paper describes the results of the analyses of High Level Waste (HLW) sludge slurry samples and of the calculations necessary to decay the radionuclides to meet the reporting requirement in the Waste Acceptance Product Specifications (WAPS) [1]. The concentrations of 45 radionuclides were measured. The results of these analyses provide input for radioactive decay calculations used to project the radionuclide inventory at the specified index years, 2015 and 3115. This information is necessary to complete the Production Records at Savannah River Site's Defense Waste Processing Facility (DWPF) so that the final glass product resulting from Macrobatch 5 (MB5) can eventually be submitted to a Federal Repository. Five of the necessary input radionuclides for the decay calculations could not be measured directly due to their low concentrations and/or analytical interferences. These isotopes are Nb-93m, Pd-107, Cd-113m, Cs-135, and Cm-248. Methods for calculating these species from concentrations of appropriate other radionuclides will be discussed. Also the average age of the MB5 HLW had to be calculated from decay of Sr-90 in order to predict the initial concentration of Nb-93m. As a result of the measurements and calculations, thirty-one WAPS reportable radioactive isotopes were identified for MB5. The total activity of MB5 …
Date: December 31, 2008
Creator: Bannochie, C; David Diprete, D & Ned Bibler, N
Object Type: Article
System: The UNT Digital Library
Feasibility Study of Hydrogen Production from Existing Nuclear Power Plants Using Alkaline Electrolysis (open access)

Feasibility Study of Hydrogen Production from Existing Nuclear Power Plants Using Alkaline Electrolysis

The mid-range industrial market currently consumes 4.2 million metric tons of hydrogen per year and has an annual growth rate of 15% industries in this range require between 100 and 1000 kilograms of hydrogen per day and comprise a wide range of operations such as food hydrogenation, electronic chip fabrication, metals processing and nuclear reactor chemistry modulation.
Date: December 31, 2008
Creator: Swalla, Dana R.
Object Type: Report
System: The UNT Digital Library
Scalable parallel Newton-Krylov solvers for discontinuous Galerkin discretizations (open access)

Scalable parallel Newton-Krylov solvers for discontinuous Galerkin discretizations

We present techniques for implicit solution of discontinuous Galerkin discretizations of the Navier-Stokes equations on parallel computers. While a block-Jacobi method is simple and straight-forward to parallelize, its convergence properties are poor except for simple problems. Therefore, we consider Newton-GMRES methods preconditioned with block-incomplete LU factorizations, with optimized element orderings based on a minimum discarded fill (MDF) approach. We discuss the difficulties with the parallelization of these methods, but also show that with a simple domain decomposition approach, most of the advantages of the block-ILU over the block-Jacobi preconditioner are still retained. The convergence is further improved by incorporating the matrix connectivities into the mesh partitioning process, which aims at minimizing the errors introduced from separating the partitions. We demonstrate the performance of the schemes for realistic two- and three-dimensional flow problems.
Date: December 31, 2008
Creator: Persson, P.-O.
Object Type: Article
System: The UNT Digital Library
Greensheet (Houston, Tex.), Vol. 39, No. 570, Ed. 1 Wednesday, December 31, 2008 (open access)

Greensheet (Houston, Tex.), Vol. 39, No. 570, Ed. 1 Wednesday, December 31, 2008

Free weekly newspaper that includes business and classified advertising.
Date: December 31, 2008
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History
Cherokeean Herald (Rusk, Tex.), Vol. 159, No. 45, Ed. 1 Wednesday, December 31, 2008 (open access)

Cherokeean Herald (Rusk, Tex.), Vol. 159, No. 45, Ed. 1 Wednesday, December 31, 2008

Weekly newspaper from Rusk, Texas that includes local, state and national news along with extensive advertising.
Date: December 31, 2008
Creator: Whitehead, Marie
Object Type: Newspaper
System: The Portal to Texas History
Greenhouse Gas Emission Drivers: Population, Economic Development and Growth, and Energy Use (open access)

Greenhouse Gas Emission Drivers: Population, Economic Development and Growth, and Energy Use

The interactions of three variables underlie debates on the issue of climate change and what responses might be justified: the magnitude and rates of change of (1) population growth, (2) incomes, and (3) intensity of greenhouse gas emissions relative to economic activities. This report examines the interrelationships of the variables to explore their implications for policies that address climate change.
Date: December 31, 2008
Creator: Blodgett, John & Parker, Larry
Object Type: Report
System: The UNT Digital Library
300 Area Integrated Field-Scale Subsurface Research Challenge (IFRC) Field Site Management Plan (open access)

300 Area Integrated Field-Scale Subsurface Research Challenge (IFRC) Field Site Management Plan

Pacific Northwest National Laboratory (PNNL) has established the 300 Area Integrated Field-Scale Subsurface Research Challenge (300 Area IFRC) on the Hanford Site in southeastern Washington State for the U.S. Department of Energy’s (DOE) Office of Biological and Environmental Research (BER) within the Office of Science. The project is funded by the Environmental Remediation Sciences Division (ERSD). The purpose of the project is to conduct research at the 300 IFRC to investigate multi-scale mass transfer processes associated with a subsurface uranium plume impacting both the vadose zone and groundwater. The management approach for the 300 Area IFRC requires that a Field Site Management Plan be developed. This is an update of the plan to reflect the installation of the well network and other changes.
Date: December 31, 2008
Creator: Freshley, Mark D.
Object Type: Report
System: The UNT Digital Library
Advanced Hybrid Propulsion and Energy Management System for High Efficiency, Off Highway, 240 Ton Class, Diesel Electric Haul Trucks (open access)

Advanced Hybrid Propulsion and Energy Management System for High Efficiency, Off Highway, 240 Ton Class, Diesel Electric Haul Trucks

The objective of this project is to reduce the fuel consumption of off-highway vehicles, specifically large tonnage mine haul trucks. A hybrid energy storage and management system will be added to a conventional diesel-electric truck that will allow capture of braking energy normally dissipated in grid resistors as heat. The captured energy will be used during acceleration and motoring, reducing the diesel engine load, thus conserving fuel. The project will work towards a system validation of the hybrid system by first selecting an energy storage subsystem and energy management subsystem. Laboratory testing at a subscale level will evaluate these selections and then a full-scale laboratory test will be performed. After the subsystems have been proven at the full-scale lab, equipment will be mounted on a mine haul truck and integrated with the vehicle systems. The integrated hybrid components will be exercised to show functionality, capability, and fuel economy impacts in a mine setting.
Date: December 31, 2008
Creator: Richter, Tim; Slezak, Lee; Johnson, Chris; Young, Henry & Funcannon, Dan
Object Type: Report
System: The UNT Digital Library
Evaluation of the Emission, Transport, and Deposition of Mercury and Fine Particulate Matter from Coal-Based Power Plants in the Ohio River Valley Region (open access)

Evaluation of the Emission, Transport, and Deposition of Mercury and Fine Particulate Matter from Coal-Based Power Plants in the Ohio River Valley Region

As stated in the proposal: Ohio University, in collaboration with CONSOL Energy, Advanced Technology Systems, Inc (ATS) and Atmospheric and Environmental Research, Inc. (AER) as subcontractors, evaluated the impact of emissions from coal-fired power plants in the Ohio River Valley region as they relate to the transport and deposition of mercury and associated fine particulate matter. This evaluation involved two interrelated areas of effort: ambient air monitoring and regional-scale modeling analysis. The scope of work for the ambient air monitoring included the deployment of a surface air monitoring (SAM) station in southeastern Ohio. The SAM station contains sampling equipment to collect and measure mercury (including speciated forms of mercury and wet and dry deposited mercury), particulate matter (PM) mass, PM composition, and gaseous criteria pollutants (CO, NOx, SO2, O3, etc.). Laboratory analyses of time-integrated samples were used to obtain chemical speciation of ambient PM composition and mercury in precipitation. Nearreal- time measurements were used to measure the ambient concentrations of PM mass and all gaseous species including Hg0 and RGM. Approximately 30 months of field data were collected at the SAM site to validate the proposed regional model simulations for episodic and seasonal model runs. The ambient air quality data …
Date: December 31, 2008
Creator: Crist, Kevin
Object Type: Report
System: The UNT Digital Library
Fly Ash and Mercury Oxidation/Chlorination Reactions (open access)

Fly Ash and Mercury Oxidation/Chlorination Reactions

Mercury is a known pollutant that has detrimental effect on human health and environment. The anthropogenic emissions of mercury account for 10 to 30% of worldwide mercury emissions. There is a need to control/reduce anthropogenic mercury emissions. Many mercury control technologies are available but their effectiveness is dependent on the chemical form of mercury, because different chemical forms of mercury have different physical and chemical properties. Mercury leaves the boiler in its elemental form but goes through various transformations in the post-combustion zone. There is a need to understand how fly ash and flue gas composition affect speciation, partitioning, and reactions of mercury under the full range of post-combustion zone conditions. This knowledge can then be used to predict the chemical transformation of mercury (elemental, oxidized or particulate) in the post combustion zone and thus help with the control of mercury emissions from coal-burning power plants. To accomplish this goal present study was conducted using five coal fly ashes. These ashes were characterized and their catalytic activity was compared under selected reaction conditions in a fixed bed reactor. Based on the results from these fly ash experiments, three key components (carbon, iron oxide and calcium oxide) were chosen. These three …
Date: December 31, 2008
Creator: Sidhu, Sukh & Varanasi, Patanjali
Object Type: Report
System: The UNT Digital Library
Energy Dense, Lighweight, Durable, Systems for Storage and Delivery of Hydrogen (open access)

Energy Dense, Lighweight, Durable, Systems for Storage and Delivery of Hydrogen

The work presented in this report summarizes the current state-of-the-art in on-board storage on compressed gaseous hydrogen as well as the development of analysis tools, methods, and theoretical data for devising high performance design configurations for hydrogen storage. The state-of-the-art in the area of compressed hydrogen storage reveals that the current configuration of the hydrogen storage tank is a seamless cylindrical part with two end domes. The tank is composed of an aluminum liner overwrapped with carbon fibers. Such a configuration was proved to sustain internal pressures up to 350 bars (5,000 psi). Finite-element stress analyses were performed on filament-wound hydrogen storage cylindrical tanks under the effect of internal pressure of 700 bars (10,000 psi). Tank deformations, stress fields, and intensities induced at the tank wall were examined. The results indicated that the aluminum liner can not sustain such a high pressure and initiate the tank failure. Thus, hydrogen tanks ought to be built entirely out of composite materials based on carbon fibers or other innovative composite materials. A spherical hydrogen storage tank was suggested within the scope of this project. A stress reduction was achieved by this change of the tank geometry, which allows for increasing the amount of …
Date: December 31, 2008
Creator: Pruez, Jacky; Shoukry, Samir; William, Gergis; Evans, Thomas & Alcazar, Hermann
Object Type: Report
System: The UNT Digital Library
The Greensheet (Dallas, Tex.), Vol. 32, No. 267, Ed. 1 Wednesday, December 31, 2008 (open access)

The Greensheet (Dallas, Tex.), Vol. 32, No. 267, Ed. 1 Wednesday, December 31, 2008

Free weekly newspaper that includes business and classified advertising.
Date: December 31, 2008
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History
Greensheet (Houston, Tex.), Vol. 39, No. 569, Ed. 1 Wednesday, December 31, 2008 (open access)

Greensheet (Houston, Tex.), Vol. 39, No. 569, Ed. 1 Wednesday, December 31, 2008

Free weekly newspaper that includes business and classified advertising.
Date: December 31, 2008
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History
Evaluation of Wax Deposition and Its Control During Production of Alaska North Slope Oils (open access)

Evaluation of Wax Deposition and Its Control During Production of Alaska North Slope Oils

Due to increasing oil demand, oil companies are moving into arctic environments and deep-water areas for oil production. In these regions of lower temperatures, wax deposits begin to form when the temperature in the wellbore falls below wax appearance temperature (WAT). This condition leads to reduced production rates and larger pressure drops. Wax problems in production wells are very costly due to production down time for removal of wax. Therefore, it is necessary to develop a solution to wax deposition. In order to develop a solution to wax deposition, it is essential to characterize the crude oil and study phase behavior properties. The main objective of this project was to characterize Alaskan North Slope crude oil and study the phase behavior, which was further used to develop a dynamic wax deposition model. This report summarizes the results of the various experimental studies. The subtasks completed during this study include measurement of density, molecular weight, viscosity, pour point, wax appearance temperature, wax content, rate of wax deposition using cold finger, compositional characterization of crude oil and wax obtained from wax content, gas-oil ratio, and phase behavior experiments including constant composition expansion and differential liberation. Also, included in this report is the …
Date: December 31, 2008
Creator: Zhu, Tao; Walker, Jack A. & Liang, J.
Object Type: Report
System: The UNT Digital Library
Arctic Energy Technology Development Laboratory (Part 2) (open access)

Arctic Energy Technology Development Laboratory (Part 2)

Methane (CH{sub 4}) in natural gas is a major energy source in the U.S., and is used extensively on Alaska's North Slope, including the oilfields in Prudhoe Bay, the community of Barrow, and the National Petroleum Reserve, Alaska (NPRA). Smaller villages, however, are dependent on imported diesel fuel for both power and heating, resulting in some of the highest energy costs in the U.S. and crippling local economies. Numerous CH{sub 4} gas seeps have been observed on wetlands near Atqasuk, Alaska (in the NPRA), and initial measurements have indicated flow rates of 3,000-5,000 ft{sup 3} day{sup -1} (60-100 kg CH{sub 4} day{sup -1}). Gas samples collected in 1996 indicated biogenic origin, although more recent sampling indicated a mixture of biogenic and thermogenic gas. In this study, we (1) quantified the amount of CH{sub 4} generated by several seeps and evaluated their potential use as an unconventional gas source for the village of Atqasuk; (2) collected gas and analyzed its composition from multiple seeps several miles apart to see if the source is the same, or if gas is being generated locally from isolated biogenic sources; and (3) assessed the potential magnitude of natural CH{sub 4} gas seeps for future use …
Date: December 31, 2008
Creator: 960443, See OSTI ID Number
Object Type: Report
System: The UNT Digital Library
Sustainable Scientists (open access)

Sustainable Scientists

Scientists are front and center in quantifying and solving environmental problems. Yet, as a spate of recent news articles in scientific journals point out, much can be done to enhance sustainability within the scientific enterprise itself, particularly by trimming the energy use associated with research facilities and the equipment therein (i,ii,iii, iv). Sponsors of research unwittingly spend on the order of $10 billion each year on energy in the U.S. alone, and the underlying inefficiencies drain funds from the research enterprise while causing 80 MT CO2-equivalent greenhouse-gas emissions (see Box). These are significant sums considering the opportunity costs in terms of the amount of additional research that could be funded and emissions that could be reduced if the underlying energy was used more efficiently. By following commercially proven best practices in facility design and operation, scientists--and the sponsors of science--can cost-effectively halve these costs, while doing their part to put society on alow-carbon diet.
Date: December 31, 2008
Creator: Mills, Evan
Object Type: Article
System: The UNT Digital Library
Results Of The Excreta Bioassay Quality Control Program For April 1, 2007 Through March 31, 2008 (open access)

Results Of The Excreta Bioassay Quality Control Program For April 1, 2007 Through March 31, 2008

A total of 79 urine samples, 3 blank fecal and 5 spiked artificial fecal samples were submitted during the report period (April 1, 2007 through March 31, 2008) to General Engineering Laboratories, South Carolina by the Hanford Internal Dosimetry Program (IDP) to check the accuracy, precision, and detection levels of their analyses. Urine analyses for tritium, Sr, 238Pu, 239Pu, 241Am, 243Am 235U, 238U, elemental uranium and fecal analyses for 241Am, 238Pu and 239Pu were tested this year. The number of QC urine samples submitted during the report period represented 1.8% of the total samples submitted. In addition to the samples provided by IDP, GEL was also required to conduct their own QC program, and submit the results of analyses to IDP. About 35% of the analyses processed by GEL during the third year of this contract were quality control samples. GEL tested the performance of 24 radioisotopes, all of which met or exceeded the specifications in the Statement of Work within statistical uncertainty (Table 4). IDP concluded that GEL was performing well for all analyses tested, and concerns identified earlier were satisfactorily resolved.
Date: December 31, 2008
Creator: Antonio, Cheryl L.
Object Type: Report
System: The UNT Digital Library
Galena Electric Power A Situational Analysis (open access)

Galena Electric Power A Situational Analysis

The purpose of the investigation is to compare the economics of various electrical power generation options for the City of Galena. Options were assessed over a 30-year project period, beginning in 2010, and the final results were compared on the basis of residential customer electric rates ($/kWh). Galena's electric utility currently generates power using internal combustion diesel engines and generator sets. Nearby, there is an exposed coal seam, which might provide fuel for a power plant. Contributions to the energy mix might come from solar, municipal solid waste, or wood. The City has also been approached by Toshiba, Inc., as a demonstration site for a small (Model 4S) nuclear reactor power plant. The Yukon River is possibly a site for in-river turbines for hydroelectric power. This report summarizes the comparative economics of various energy supply options. This report covers: (1) thermal and electric load profiles for Galena; (2) technologies and resources available to meet or exceed those loads; (3) uses for any extra power produced by these options; (4) environmental and permitting issues and then; and (5) the overall economics of each of the primary energy options.
Date: December 31, 2008
Creator: Chaney, Robert E.; Colt, Stephen G.; Johnson, Ronald A.; Wiles, Richard W. & White, Gregory J.
Object Type: Report
System: The UNT Digital Library
Phase Behavior, Solid Organic Precipitation, and Mobility Characterization Studies in Support of Enhanced Heavy Oil Recovery on the Alaska North Slope (open access)

Phase Behavior, Solid Organic Precipitation, and Mobility Characterization Studies in Support of Enhanced Heavy Oil Recovery on the Alaska North Slope

The medium-heavy oil (viscous oil) resources in the Alaska North Slope are estimated at 20 to 25 billion barrels. These oils are viscous, flow sluggishly in the formations, and are difficult to recover. Recovery of this viscous oil requires carefully designed enhanced oil recovery processes. Success of these recovery processes is critically dependent on accurate knowledge of the phase behavior and fluid properties, especially viscosity, of these oils under variety of pressure and temperature conditions. This project focused on predicting phase behavior and viscosity of viscous oils using equations of state and semi-empirical correlations. An experimental study was conducted to quantify the phase behavior and physical properties of viscous oils from the Alaska North Slope oil field. The oil samples were compositionally characterized by the simulated distillation technique. Constant composition expansion and differential liberation tests were conducted on viscous oil samples. Experiment results for phase behavior and reservoir fluid properties were used to tune the Peng-Robinson equation of state and predict the phase behavior accurately. A comprehensive literature search was carried out to compile available compositional viscosity models and their modifications, for application to heavy or viscous oils. With the help of meticulously amassed new medium-heavy oil viscosity data from …
Date: December 31, 2008
Creator: Patil, Shirish; Dandekar, Abhijit & Khataniar, Santanu
Object Type: Report
System: The UNT Digital Library
Effects of Village Power Quality on Fuel Consumption and Operating Expenses (open access)

Effects of Village Power Quality on Fuel Consumption and Operating Expenses

Alaska's rural village electric utilities are isolated from the Alaska railbelt electrical grid intertie and from each other. Different strategies have been developed for providing power to meet demand in each of these rural communities. Many of these communities rely on diesel electric generators (DEGs) for power. Some villages have also installed renewable power sources and automated generation systems for controlling the DEGs and other sources of power. For example, Lime Village has installed a diesel battery photovoltaic hybrid system, Kotzebue and Wales have wind-diesel hybrid systems, and McGrath has installed a highly automated system for controlling diesel generators. Poor power quality and diesel engine efficiency in village power systems increases the cost of meeting the load. Power quality problems may consist of poor power factor (PF) or waveform disturbances, while diesel engine efficiency depends primarily on loading, the fuel type, the engine temperature, and the use of waste heat for nearby buildings. These costs take the form of increased fuel use, increased generator maintenance, and decreased reliability. With the cost of bulk fuel in some villages approaching $1.32/liter ($5.00/gallon) a modest 5% decrease in fuel use can result in substantial savings with short payback periods depending on the village's …
Date: December 31, 2008
Creator: Wies, Richard & Johnson, Ron
Object Type: Report
System: The UNT Digital Library