SOWFA Super-Controller: A High-Fidelity Tool for Evaluating Wind Plant Control Approaches (open access)

SOWFA Super-Controller: A High-Fidelity Tool for Evaluating Wind Plant Control Approaches

This paper presents a new tool for testing wind plant controllers in the Simulator for Offshore Wind Farm Applications (SOWFA). SOWFA is a high-fidelity simulator for the interaction between wind turbine dynamics and the fluid flow in a wind plant. The new super-controller testing environment in SOWFA allows for the implementation of the majority of the wind plant control strategies proposed in the literature.
Date: January 1, 2013
Creator: Fleming, P.; Gebraad, P.; van Wingerden, J. W.; Lee, S.; Churchfield, M.; Scholbrock, A. et al.
System: The UNT Digital Library
Comparison between the United States and United Kingdom Criticality Safety Personnel Training Program Guidance (open access)

Comparison between the United States and United Kingdom Criticality Safety Personnel Training Program Guidance

None
Date: January 9, 2013
Creator: Wysong, A R; Heinrichs, D P & Tancock, N P
System: The UNT Digital Library
A geomechanical mechanism that counteracts flow channeling induced by reservoir thermal drawdown (open access)

A geomechanical mechanism that counteracts flow channeling induced by reservoir thermal drawdown

None
Date: January 30, 2013
Creator: Fu, P; Hao, Y & Carrigan, C R
System: The UNT Digital Library
Physics of Radiation-driven Islands Near the Tokamak Density Limit (open access)

Physics of Radiation-driven Islands Near the Tokamak Density Limit

In previous work [1], the onset criterion for radiation driven islands [2] in combination with a simple cylindrical model of tokamak current channel behavior was shown to be consistent with the empirical scaling of the tokamak density limit [3]. A number of the unexplained phenomena at the density limit are consistent with this novel physics mechanism. In this work, a more formal theoretical underpinning, consistent with cylindrical tearing mode theory, is developed for the onset criteria of these modes. The appropriate derivation of the radiation-driven addition to the modified Rutherford equation is discussed. Additionally, the ordering of the terms in the MRE is examined in a regime near the density limit. It is hoped that given the apparent success of this simple model in explaining the observed global scalings will lead to a more comprehensive analysis of the possibility that radiation driven islands are the physics mechanism responsible for the density limit. In particular, with modern diagnostic capabilities detailed measurements of current densities, electron densities and impurity concentrations at rational surfaces should be possible, enabling verification of the concepts described above.
Date: January 10, 2013
Creator: D.A. Gates, L. Delgado-Apricio and R.B. White
System: The UNT Digital Library
Reversible Graphene-metal Contact through Hydrogenation (open access)

Reversible Graphene-metal Contact through Hydrogenation

None
Date: January 8, 2013
Creator: Rajasekaran, Srivats; Kaya, Sarp; Abild-Pedersen, Frank; Anniyev, Toyli; Yang, Fan; Stacchiola, Dario et al.
System: The UNT Digital Library
Electron neutrino and antineutrino appearance in the full MINOS data sample (open access)

Electron neutrino and antineutrino appearance in the full MINOS data sample

None
Date: January 1, 2013
Creator: Adamson, P. & al., et
System: The UNT Digital Library
Reevaluation Of Vitrified High-Level Waste Form Criteria For Potential Cost Savings At The Defense Waste Processing Facility (open access)

Reevaluation Of Vitrified High-Level Waste Form Criteria For Potential Cost Savings At The Defense Waste Processing Facility

At the Savannah River Site (SRS) the Defense Waste Processing Facility (DWPF) has been immobilizing SRS's radioactive high level waste (HLW) sludge into a durable borosilicate glass since 1996. Currently the DWPF has poured over 3,500 canisters, all of which are compliant with the U. S. Department of Energy's (DOE) Waste Acceptance Product Specifications for Vitrified High-Level Waste Forms (WAPS) and therefore ready to be shipped to a federal geologic repository for permanent disposal. Due to DOE petitioning to withdraw the Yucca Mountain License Application (LA) from the Nuclear Regulatory Commission (NRC) in 2010 and thus no clear disposal path for SRS canistered waste forms, there are opportunities for cost savings with future canister production at DWPF and other DOE producer sites by reevaluating high-level waste form requirements and compliance strategies and reducing/eliminating those that will not negatively impact the quality of the canistered waste form.
Date: January 9, 2013
Creator: Ray, J. W.; Marra, S. L. & Herman, C. C.
System: The UNT Digital Library
Advances in Glass Formulations for Hanford High-Alumimum, High-Iron and Enhanced Sulphate Management in HLW Streams - 13000 (open access)

Advances in Glass Formulations for Hanford High-Alumimum, High-Iron and Enhanced Sulphate Management in HLW Streams - 13000

The current estimates and glass formulation efforts have been conservative in terms of achievable waste loadings. These formulations have been specified to ensure that the glasses are homogenous, contain essentially no crystalline phases, are processable in joule-heated, ceramic-lined melters and meet Hanford Tank Waste Treatment and Immobilization Plant (WTP) Contract terms. The WTP?s overall mission will require the immobilization of tank waste compositions that are dominated by mixtures of aluminum (Al), chromium (Cr), bismuth (Bi), iron (Fe), phosphorous (P), zirconium (Zr), and sulphur (S) compounds as waste-limiting components. Glass compositions for these waste mixtures have been developed based upon previous experience and current glass property models. Recently, DOE has initiated a testing program to develop and characterize HLW glasses with higher waste loadings and higher throughput efficiencies. Results of this work have demonstrated the feasibility of increases in waste loading from about 25 wt% to 33-50 wt% (based on oxide loading) in the glass depending on the waste stream. In view of the importance of aluminum limited waste streams at Hanford (and also Savannah River), the ability to achieve high waste loadings without adversely impacting melt rates has the potential for enormous cost savings from reductions in canister count and …
Date: January 16, 2013
Creator: Kruger, Albert A.
System: The UNT Digital Library
Lessons Learned from the 200 West Pump and Treatment Facility Construction Project at the US DOE Hanford Site - A Leadership for Energy and Environmental Design (LEED) Gold-Certified Facility (open access)

Lessons Learned from the 200 West Pump and Treatment Facility Construction Project at the US DOE Hanford Site - A Leadership for Energy and Environmental Design (LEED) Gold-Certified Facility

CH2M Hill Plateau Remediation Company (CHPRC) designed, constructed, commissioned, and began operation of the largest groundwater pump and treatment facility in the U.S. Department of Energy’s (DOE) nationwide complex. This one-of-a-kind groundwater pump and treatment facility, located at the Hanford Nuclear Reservation Site (Hanford Site) in Washington State, was built to an accelerated schedule with American Recovery and Reinvestment Act (ARRA) funds. There were many contractual, technical, configuration management, quality, safety, and Leadership in Energy and Environmental Design (LEED) challenges associated with the design, procurement, construction, and commissioning of this $95 million, 52,000 ft groundwater pump and treatment facility to meet DOE’s mission objective of treating contaminated groundwater at the Hanford Site with a new facility by June 28, 2012. The project team’s successful integration of the project’s core values and green energy technology throughout design, procurement, construction, and start-up of this complex, first-of-its-kind Bio Process facility resulted in successful achievement of DOE’s mission objective, as well as attainment of LEED GOLD certification, which makes this Bio Process facility the first non-administrative building in the DOE Office of Environmental Management complex to earn such an award.
Date: January 11, 2013
Creator: Dorr, Kent A.; Ostrom, Michael J. & Freeman-Pollard, Jhivaun R.
System: The UNT Digital Library
RAPID DETERMINATION OF RADIOSTRONTIUM IN SEAWATER SAMPLES (open access)

RAPID DETERMINATION OF RADIOSTRONTIUM IN SEAWATER SAMPLES

A new method for the determination of radiostrontium in seawater samples has been developed at the Savannah River National Laboratory (SRNL) that allows rapid preconcentration and separation of strontium and yttrium isotopes in seawater samples for measurement. The new SRNL method employs a novel and effective pre-concentration step that utilizes a blend of calcium phosphate with iron hydroxide to collect both strontium and yttrium rapidly from the seawater matrix with enhanced chemical yields. The pre-concentration steps, in combination with rapid Sr Resin and DGA Resin cartridge separation options using vacuum box technology, allow seawater samples up to 10 liters to be analyzed. The total {sup 89}Sr + {sup 90}Sr activity may be determined by gas flow proportional counting and recounted after ingrowth of {sup 90}Y to differentiate {sup 89}Sr from {sup 90}Sr. Gas flow proportional counting provides a lower method detection limit than liquid scintillation or Cerenkov counting and allows simultaneous counting of samples. Simultaneous counting allows for longer count times and lower method detection limits without handling very large aliquots of seawater. Seawater samples up to 6 liters may be analyzed using Sr Resin for {sup 89}Sr and {sup 90}Sr with a Minimum Detectable Activity (MDA) of 1-10 mBq/L, …
Date: January 16, 2013
Creator: Maxwell, S.
System: The UNT Digital Library
Advanced Platform for Development and Evaluation of Grid Interconnection Systems Using Hardware-in-the-Loop: Part III -- Grid Interconnection System Evaluator: Preprint (open access)

Advanced Platform for Development and Evaluation of Grid Interconnection Systems Using Hardware-in-the-Loop: Part III -- Grid Interconnection System Evaluator: Preprint

This paper, presented at the IEEE Green Technologies Conference 2013, describes a Grid Interconnection System Evaluator (GISE) that leverages hardware-in-the-loop (HIL) simulation techniques to rapidly evaluate the grid interconnection standard conformance of an ICS according to the procedures in IEEE Std 1547.1 (TM). The architecture and test sequencing of this evaluation tool, along with a set of representative ICS test results from three different photovoltaic (PV) inverters, are presented. The GISE adds to the National Renewable Energy Laboratory's (NREL) evaluation platform that now allows for rapid development of ICS control algorithms using controller HIL (CHIL) techniques, the ability to test the dc input characteristics of PV-based ICSs through the use of a PV simulator capable of simulating real-world dynamics using power HIL (PHIL), and evaluation of ICS grid interconnection conformance.
Date: January 1, 2013
Creator: Lundstrom, B.; Shirazi, M.; Coddington, M. & Kroposki, B.
System: The UNT Digital Library
An Initial Evaluation Of Characterization And Closure Options For Underground Pipelines Within A Hanford Site Single-Shell Tank Farm (open access)

An Initial Evaluation Of Characterization And Closure Options For Underground Pipelines Within A Hanford Site Single-Shell Tank Farm

The Hanford Site includes 149 single-shell tanks, organized in 12 'tank farms,' with contents managed as high-level mixed waste. The Hanford Federal Facility Agreement and Consent Order requires that one tank farm, the Waste Management Area C, be closed by June 30, 2019. A challenge to this project is the disposition and closure of Waste Management Area C underground pipelines. Waste Management Area C contains nearly seven miles of pipelines and 200 separate pipe segments. The pipelines were taken out of service decades ago and contain unknown volumes and concentrations of tank waste residuals from past operations. To understand the scope of activities that may be required for these pipelines, an evaluation was performed. The purpose of the evaluation was to identify what, if any, characterization methods and/or closure actions may be implemented at Waste Management Area C for closure of Waste Management Area C by 2019. Physical and analytical data do not exist for Waste Management Area C pipeline waste residuals. To develop estimates of residual volumes and inventories of contamination, an extensive search of available information on pipelines was conducted. The search included evaluating historical operation and occurrence records, physical attributes, schematics and drawings, and contaminant inventories associated …
Date: January 10, 2013
Creator: Badden, Janet W.; Connelly, Michael P.; Seeley, Paul N. & Hendrickson, Michelle L.
System: The UNT Digital Library
Sideband Algorithm for Automatic Wind Turbine Gearbox Fault Detection and Diagnosis: Preprint (open access)

Sideband Algorithm for Automatic Wind Turbine Gearbox Fault Detection and Diagnosis: Preprint

Improving the availability of wind turbines (WT) is critical to minimize the cost of wind energy, especially for offshore installations. As gearbox downtime has a significant impact on WT availabilities, the development of reliable and cost-effective gearbox condition monitoring systems (CMS) is of great concern to the wind industry. Timely detection and diagnosis of developing gear defects within a gearbox is an essential part of minimizing unplanned downtime of wind turbines. Monitoring signals from WT gearboxes are highly non-stationary as turbine load and speed vary continuously with time. Time-consuming and costly manual handling of large amounts of monitoring data represent one of the main limitations of most current CMSs, so automated algorithms are required. This paper presents a fault detection algorithm for incorporation into a commercial CMS for automatic gear fault detection and diagnosis. The algorithm allowed the assessment of gear fault severity by tracking progressive tooth gear damage during variable speed and load operating conditions of the test rig. Results show that the proposed technique proves efficient and reliable for detecting gear damage. Once implemented into WT CMSs, this algorithm can automate data interpretation reducing the quantity of information that WT operators must handle.
Date: January 1, 2013
Creator: Zappala, D.; Tavner, P.; Crabtree, C. & Sheng, S.
System: The UNT Digital Library
Role of internal gases and creep of Ag in controlling the critical current density of Ag-sheathed Bi2Sr2CaCu2Ox wires (open access)

Role of internal gases and creep of Ag in controlling the critical current density of Ag-sheathed Bi2Sr2CaCu2Ox wires

None
Date: January 1, 2013
Creator: Shen, T.; Cooley, L.; Ghosh, A. & Jiang, J.
System: The UNT Digital Library
Quantification Of Aluminum Increase Factors for Curtainwall Design Using Finite Element Methods (open access)

Quantification Of Aluminum Increase Factors for Curtainwall Design Using Finite Element Methods

None
Date: January 11, 2013
Creator: Leininger, L D & Gallant, S M
System: The UNT Digital Library
Traverse Focusing of Intense Charged Particle Beams with Chromatic Effects for Heavy Ion Fusion (open access)

Traverse Focusing of Intense Charged Particle Beams with Chromatic Effects for Heavy Ion Fusion

A fi nal focusing scheme designed to minimize chromatic effects is discussed. The Neutralized Drift Compression Experiment-II (NDCX-II) will apply a velocity tilt for longitudinal bunch compression, and a fi nal focusing solenoid (FFS) for transverse bunch compression. In the beam frame, neutralized drift compression causes a suffi#14;ciently large spread in axial momentum, pz , resulting in chromatic effects to the fi nal focal spot during transverse bunch compression. Placing a weaker solenoid upstream of a stronger fi nal focusing solenoid (FFS) mitigates chromatic effects and improves transverse focusing by a factor of approximately 2-4 for appropriate NDCX-II parameters.
Date: January 28, 2013
Creator: James M. Mitrani, Igor D. Kaganovich, Ronald C. Davidson
System: The UNT Digital Library
Is It Time for a Class 5 Laser? (open access)

Is It Time for a Class 5 Laser?

None
Date: January 3, 2013
Creator: King, J. J.
System: The UNT Digital Library
The Component Slope Linear Model for Calculating Intensive Partial Molar Properties: Application to Waste Glasses (open access)

The Component Slope Linear Model for Calculating Intensive Partial Molar Properties: Application to Waste Glasses

Partial molar properties are the changes occurring when the fraction of one component is varied while the fractions of all other component mole fractions change proportionally. They have many practical and theoretical applications in chemical thermodynamics. Partial molar properties of chemical mixtures are difficult to measure because the component mole fractions must sum to one, so a change in fraction of one component must be offset with a change in one or more other components. Given that more than one component fraction is changing at a time, it is difficult to assign a change in measured response to a change in a single component. In this study, the Component Slope Linear Model (CSLM), a model previously published in the statistics literature, is shown to have coefficients that correspond to the intensive partial molar properties. If a measured property is plotted against the mole fraction of a component while keeping the proportions of all other components constant, the slope at any given point on a graph of this curve is the partial molar property for that constituent. Actually plotting this graph has been used to determine partial molar properties for many years. The CSLM directly includes this slope in a model …
Date: January 11, 2013
Creator: Reynolds, Jacob G.
System: The UNT Digital Library
CO Oxidation at the Interface of Au Nanoclusters and the Stepped-CeO2(111) Surface (open access)

CO Oxidation at the Interface of Au Nanoclusters and the Stepped-CeO2(111) Surface

To reveal the richer chemistry of CO oxidation by CeO2 supported Au Nanoclusters NCs)/Nanoparticles, we design a Au12 supported on a stepped-CeO2 model (Au/CeO2-step) and study various kinds of CO oxidation mechanisms at the interface of the Au/CeO2-step: oxygen spillover from the CeO2 to the Au NCs;2 CO oxidation by the O2 bound to the Au-Ce3+ interface;3 and CO oxidation by the Mars-van Krevelen (M-vK) mechanism.4 DFT+U calculations show that lattice oxygen at the CeO2 step edge oxidizes CO bound to Au NCs by the M-vK mechanism. CO2 desorption determines the rate of CO oxidation and the vacancy formation energy (Evac) is a reactivity descriptor for CO oxidation. The maximum Evac that insures spontaneous CO2 production is higher for the Au/CeO2-step than the Au/CeO2-surface suggesting that the CeO2-step is a better supporting material than the CeO2-surface for CO oxidation by the Au/CeO2. Our results also suggest that for CO oxidation by Au NCs supported on nano- or meso-structured CeO2, which is the case of industrial catalysts, the M-vK mechanism accounts for a large portion of the total activity.
Date: January 14, 2013
Creator: Y., Kim H. & Henkelman, G.
System: The UNT Digital Library
Accounting for the Variation of Driver Aggression in the Simulation of Conventional and Advanced Vehicles (open access)

Accounting for the Variation of Driver Aggression in the Simulation of Conventional and Advanced Vehicles

Hybrid electric vehicles, plug-in hybrid electric vehicles, and battery electric vehicles offer the potential to reduce both oil imports and greenhouse gases, as well as to offer a financial benefit to the driver. However, assessing these potential benefits is complicated by several factors, including the driving habits of the operator. We focus on driver aggression, i.e., the level of acceleration and velocity characteristic of travel, to (1) assess its variation within large, real-world drive datasets, (2) quantify its effect on both vehicle efficiency and economics for multiple vehicle types, (3) compare these results to those of standard drive cycles commonly used in the industry, and (4) create a representative drive cycle for future analyses where standard drive cycles are lacking.
Date: January 1, 2013
Creator: Neubauer, J. & Wood, E.
System: The UNT Digital Library
A microscopic theory of low energy fission: fragment properties (open access)

A microscopic theory of low energy fission: fragment properties

None
Date: January 11, 2013
Creator: Younes, W.; Gogny, D. & Schunck, N.
System: The UNT Digital Library
Expediting Groundwater Sampling at Hanford and Making It Safer (open access)

Expediting Groundwater Sampling at Hanford and Making It Safer

The CH2M HILL Plateau Remediation Company (CHPRC) manages the groundwatermonitoring programs at the Department of Energy's 586-square-mile Hanford site in southeastern Washington state. These programs are regulated by the Resource Conservation and Recovery Act (RCRA), the Comprehensive Environmental Response Compensation and Liability Act (CERCLA), and the Atomic Energy Act (AEA). The purpose of monitoring is to track existing groundwater contamination from past practices, as well as other potential contamination that might originate from RCRA treatment, storage, and disposal (TSD) facilities. An integral part of the groundwater-monitoring program involves taking samples of the groundwater and measuring the water levels in wells scattered across the site. Each year, more than 1,500 wells are accessed for a variety of reasons.
Date: January 22, 2013
Creator: Connell, Carl W. Jr.; Carr, Jennifer S.; Hildebrand, R. Douglas; Schatz, Aaron L.; Conley, S. F. & Brown, W. L.
System: The UNT Digital Library
Energetics of Oxygen Adatoms, Hydroxyl Species and Water Dissociation on Pt(111) (open access)

Energetics of Oxygen Adatoms, Hydroxyl Species and Water Dissociation on Pt(111)

None
Date: January 18, 2013
Creator: Karp, Eric M.; Campbell, Charles T.; /Washington U., Dept. Chem.; Studt, Felix; Abild-Pedersen, Frank; Norskov, Jens K. et al.
System: The UNT Digital Library
CatApp: A Web Application for Surface Chemistry and Heterogeneous Catalysis (open access)

CatApp: A Web Application for Surface Chemistry and Heterogeneous Catalysis

None
Date: January 8, 2013
Creator: Hummelshoj, J.S.; Abild-Pedersen, F.; Studt, F.; Bligaard, T. & Norskov, J.K.
System: The UNT Digital Library