ARM Climate Research Facility Quarterly Value-Added Product Report First Quarter: October 01-December 31, 2011 (open access)

ARM Climate Research Facility Quarterly Value-Added Product Report First Quarter: October 01-December 31, 2011

The purpose of this report is to provide a concise status update for value-added products (VAP) implemented by the Atmospheric Radiation Measurement (ARM) Climate Research Facility. The report is divided into the following sections: (1) new VAPs for which development has begun, (2) progress on existing VAPs, (3) future VAPs that have been recently approved, (4) other work that leads to a VAP, and (5) top requested VAPs from the archive.
Date: February 28, 2012
Creator: Sivaraman, C
Object Type: Text
System: The UNT Digital Library
Autonomous Demand Response for Primary Frequency Regulation (open access)

Autonomous Demand Response for Primary Frequency Regulation

The research documented within this report examines the use of autonomous demand response to provide primary frequency response in an interconnected power grid. The work builds on previous studies in several key areas: it uses a large realistic model (i.e., the interconnection of the western United States and Canada); it establishes a set of metrics that can be used to assess the effectiveness of autonomous demand response; and it independently adjusts various parameters associated with using autonomous demand response to assess effectiveness and to examine possible threats or vulnerabilities associated with the technology.
Date: February 28, 2012
Creator: Donnelly, Matt; Trudnowski, Daniel J.; Mattix, S. & Dagle, Jeffery E.
Object Type: Report
System: The UNT Digital Library
FINAL TECHNICAL REPORT: 20% Wind by 2030: Overcoming the Challenges (open access)

FINAL TECHNICAL REPORT: 20% Wind by 2030: Overcoming the Challenges

The funds allocated through the Wind Powering America (WPA) grant were utilized by the State of Montana to support broad outreach activities communicating the benefits and opportunities of increased wind energy and transmission development. The challenges to increased wind development were also clearly communicated with the understanding that a clearer comprehension of the challenges would be beneficial in overcoming the obstacles to further development. The ultimate purpose of these activities was to foster the increased development of Montana's rich wind resources through increased public acceptance and wider dissemination of technical resources.
Date: February 28, 2012
Creator: Kaiserski, Tom & Lloyd, Dan
Object Type: Report
System: The UNT Digital Library
Final Technical Report Power through Policy: "Best Practices" for Cost-Effective Distributed Wind (open access)

Final Technical Report Power through Policy: "Best Practices" for Cost-Effective Distributed Wind

Power through Policy: 'Best Practices' for Cost-Effective Distributed Wind is a U.S. Department of Energy (DOE)-funded project to identify distributed wind technology policy best practices and to help policymakers, utilities, advocates, and consumers examine their effectiveness using a pro forma model. Incorporating a customized feed from the Database of State Incentives for Renewables and Efficiency (DSIRE), the Web-based Distributed Wind Policy Comparison Tool (Policy Tool) is designed to assist state, local, and utility officials in understanding the financial impacts of different policy options to help reduce the cost of distributed wind technologies. The project's final products include the Distributed Wind Policy Comparison Tool, found at www.windpolicytool.org, and its accompanying documentation: Distributed Wind Policy Comparison Tool Guidebook: User Instructions, Assumptions, and Case Studies. With only two initial user inputs required, the Policy Tool allows users to adjust and test a wide range of policy-related variables through a user-friendly dashboard interface with slider bars. The Policy Tool is populated with a variety of financial variables, including turbine costs, electricity rates, policies, and financial incentives; economic variables including discount and escalation rates; as well as technical variables that impact electricity production, such as turbine power curves and wind speed. The Policy Tool allows …
Date: February 28, 2012
Creator: Rhoads-Weaver, Heather; Gagne, Matthew; Sahl, Kurt; Orrell, Alice & Banks, Jennifer
Object Type: Report
System: The UNT Digital Library
Full Life Wind Turbine Gearbox Lubricating Fluids (open access)

Full Life Wind Turbine Gearbox Lubricating Fluids

Industrial gear box lubricants typically are hydrocarbon based mineral oils with considerable amounts of additives to overcome the lack of base fluid properties like wear protection, oxidation stability, load carrying capacity, low temperature solidification and drop of viscosity at higher temperatures. For today's wind turbine gearboxes, the requirements are more severe and synthetic hydrocarbon oils are used to improve on this, but all such hydrocarbon based lubricants require significant amounts of Extreme Pressure (EP) additives to meet performance requirements. Perfluoropolyether (PFPE) fluids provide load carrying capacity as an inherent property. During the course of the project with the main tasks of 'Establish a Benchmark', 'Lubricant Evaluation', 'Full Scale Gearbox Trial' and 'Economic Evaluation', the PAO Reference oil exhibited significant changes after laboratory gear testing, in service operation in the field and full scale gearbox trial. Four hydrocarbon base oils were selected for comparison in the benchmarking exercise and showed variation with respect to meeting the requirements for the laboratory micro-pitting tests, while the PFPE fluid exceeded the requirements even with the material taken after the full scale gear box trial. This is remarkable for a lubricant without EP additives. Laboratory bearing tests performed on the PFPE fluids before and after …
Date: February 28, 2012
Creator: Lutz, Glenn A.; Jungk, Manfred; Bryant, Jonathan J.; Lauer, Rebecca S.; Chobot, Anthony; Mayer, Tyler et al.
Object Type: Report
System: The UNT Digital Library
International Review of the Development and Implementation of Energy Efficiency Standards and Labeling Programs (open access)

International Review of the Development and Implementation of Energy Efficiency Standards and Labeling Programs

Appliance energy efficiency standards and labeling (S&L) programs have been important policy tools for regulating the efficiency of energy-using products for over 40 years and continue to expand in terms of geographic and product coverage. The most common S&L programs include mandatory minimum energy performance standards (MEPS) that seek to push the market for efficient products, and energy information and endorsement labels that seek to pull the market. This study seeks to review and compare some of the earliest and most well-developed S&L programs in three countries and one region: the U.S. MEPS and ENERGY STAR, Australia MEPS and Energy Label, European Union MEPS and Ecodesign requirements and Energy Label and Japanese Top Runner programs. For each program, key elements of S&L programs are evaluated and comparative analyses across the programs undertaken to identify best practice examples of individual elements as well as cross-cutting factors for success and lessons learned in international S&L program development and implementation. The international review and comparative analysis identified several overarching themes and highlighted some common factors behind successful program elements. First, standard-setting and programmatic implementation can benefit significantly from a legal framework that stipulates a specific timeline or schedule for standard-setting and revision, product …
Date: February 28, 2012
Creator: Zhou, Nan; Zheng, Nina & Fridley, David
Object Type: Report
System: The UNT Digital Library
Modular Energy Storage System for Alternative Energy Vehicles (open access)

Modular Energy Storage System for Alternative Energy Vehicles

An electrical vehicle environment was established to promote research and technology development in the area of high power energy management. The project incorporates a topology that permits parallel development of an alternative energy delivery system and an energy storage system. The objective of the project is to develop technologies, specifically power electronics, energy storage electronics and controls that provide efficient and effective energy management between electrically powered devices in alternative energy vehicles – plugin electric vehicles, hybrid vehicles, range extended vehicles, and hydrogen-based fuel cell vehicles. In order to meet the project objectives, the Vehicle Energy Management System (VEMS) was defined and subsystem requirements were obtained. Afterwards, power electronics, energy storage electronics and controls were designed. Finally, these subsystems were built, tested individually, and integrated into an electric vehicle system to evaluate and optimize the subsystems’ performance. Phase 1 of the program established the fundamental test bed to support development of an electrical environment ideal for fuel cell application and the mitigation of many shortcomings of current fuel cell technology. Phase 2, continued development from Phase 1, focusing on implementing subsystem requirements, design and construction of the energy management subsystem, and the integration of this subsystem into the surrogate electric …
Date: February 28, 2012
Creator: Thomas, Janice & Ervin, Frank
Object Type: Report
System: The UNT Digital Library
Nevada National Security Site Waste Acceptance Criteria (open access)

Nevada National Security Site Waste Acceptance Criteria

This document establishes the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Site Office (NNSA/NSO), Nevada National Security Site Waste Acceptance Criteria (NNSSWAC). The NNSSWAC provides the requirements, terms, and conditions under which the Nevada National Security Site (NNSS) will accept DOE non-radioactive classified waste, DOE non-radioactive hazardous classified waste, DOE low-level radioactive waste (LLW), DOE mixed low-level waste (MLLW), and U.S. Department of Defense (DOD) classified waste for permanent disposal. Classified waste is the only waste accepted for disposal that may be non-radioactive and will be required to meet the waste acceptance criteria for radioactive waste as specified in this document. The NNSA/NSO and support contractors are available to assist you in understanding or interpreting this document. For assistance, please call the NNSA/NSO Waste Management Project (WMP) at (702) 295-7063, and your call will be directed to the appropriate contact.
Date: February 28, 2012
Creator: National Security Technologies, LLC
Object Type: Report
System: The UNT Digital Library
PTRANSP Tests Of TGLF And Predictions For ITER (open access)

PTRANSP Tests Of TGLF And Predictions For ITER

One of the physics goals for ITER is to achieve high fusion power PDT at a high gain QDT. This goal is important for studying the physics of reactor-relevant burning plasmas. Simulations of plasma performance in ITER can help achieve this goal by aiding in the design of systems such as diagnostics and in planning ITER plasma regimes. Simulations can indicate areas where further research in theory and experiments is needed. To have credible simulations integrated modeling is necessary since plasma profiles and applied heating, torque, and current drive are strongly coupled.
Date: February 28, 2012
Creator: Budny, Robert V.; Yuan, Xingqiu; Jardin, S.; Hammett, G. & Staebler, G.
Object Type: Article
System: The UNT Digital Library
Rapid, Low-Cost Noble Gas Tracer Monitoring to Determine Travel Times at Recharge Operations (open access)

Rapid, Low-Cost Noble Gas Tracer Monitoring to Determine Travel Times at Recharge Operations

None
Date: February 28, 2012
Creator: Visser, A.; Singleton, M.; Hillegonds, D.; Velsko, C.; Moran, J. E. & Esser, B. K.
Object Type: Report
System: The UNT Digital Library
Report for Treating Hanford LAW and WTP SW Simulants: Pilot Plant Mineralizing Flowsheet (open access)

Report for Treating Hanford LAW and WTP SW Simulants: Pilot Plant Mineralizing Flowsheet

The US Department of Energy is responsible for managing the disposal of radioactive liquid waste in underground storage tanks at the Hanford site in Washington State. The Hanford waste treatment and immobilization plant (WPT) will separate the waste into a small volume of high level waste (HLW), containing most of the radioactive constituents, and a larger volume of low activity waste (LAW), containing most of the non-radioactive chemical and hazardous constituents. The HLW and LAW will be converted into immobilized waste forms for disposal. Currently there is inadequate LAW vitrification capacity planned at the WTP to complete the mission within the required timeframe. Therefore additional LAW capacity is required. One candidate supplemental treatment technology is the fluidized bed steam reformer process (FBSR). This report describes the demonstration testing of the FBSR process using a mineralizing flowsheet for treating simulated Hanford LAW and secondary waste from the WTP (WTP SW). The FBSR testing project produced leach-resistant solid products and environmentally compliant gaseous effluents. The solid products incorporated normally soluble ions into an alkali alumino-silicate (NaS) mineral matrix. Gaseous emissions were found to be within regulatory limits. Cesium and rhenium were captured in the mineralized products with system removal efficiencies of 99.999% …
Date: February 28, 2012
Creator: Olson, Arlin
Object Type: Report
System: The UNT Digital Library
Siting Study Framework and Survey Methodology for Marine and Hydrokinetic Energy Project in Offshore Southeast Florida (open access)

Siting Study Framework and Survey Methodology for Marine and Hydrokinetic Energy Project in Offshore Southeast Florida

Dehlsen Associates, LLC was awarded a grant by the United States Department of Energy (DOE) Golden Field Office for a project titled 'Siting Study Framework and Survey Methodology for Marine and Hydrokinetic Energy Project in Offshore Southeast Florida,' corresponding to DOE Grant Award Number DE-EE0002655 resulting from DOE funding Opportunity Announcement Number DE-FOA-0000069 for Topic Area 2, and it is referred to herein as 'the project.' The purpose of the project was to enhance the certainty of the survey requirements and regulatory review processes for the purpose of reducing the time, efforts, and costs associated with initial siting efforts of marine and hydrokinetic energy conversion facilities that may be proposed in the Atlantic Ocean offshore Southeast Florida. To secure early input from agencies, protocols were developed for collecting baseline geophysical information and benthic habitat data that can be used by project developers and regulators to make decisions early in the process of determining project location (i.e., the siting process) that avoid or minimize adverse impacts to sensitive marine benthic habitat. It is presumed that such an approach will help facilitate the licensing process for hydrokinetic and other ocean renewable energy projects within the study area and will assist in clarifying …
Date: February 28, 2012
Creator: Vinick, Charles; Riccobono, Antonino; Messing, Charles G.; Walker, Brian K. & Reed, John K.
Object Type: Report
System: The UNT Digital Library
User's Guide to the Energy Charting and Metrics Tool (ECAM) (open access)

User's Guide to the Energy Charting and Metrics Tool (ECAM)

The intent of this user guide is to provide a brief description of the functionality of the Energy Charting and Metrics (ECAM) tool, including the expanded building re-tuning functionality developed for Pacific Northwest National laboratory (PNNL). This document describes the tool's general functions and features, and offers detailed instructions for PNNL building re-tuning charts, a feature in ECAM intended to help building owners and operators look at trend data (recommended 15-minute time intervals) in a series of charts (both time series and scatter) to analyze air-handler, zone, and central plant information gathered from a building automation system (BAS).
Date: February 28, 2012
Creator: Taasevigen, Danny J. & Koran, William
Object Type: Report
System: The UNT Digital Library
CRITICAL ASSUMPTIONS IN THE F-TANK FARM CLOSURE OPERATIONAL DOCUMENTATION REGARDING WASTE TANK INTERNAL CONFIGURATIONS (open access)

CRITICAL ASSUMPTIONS IN THE F-TANK FARM CLOSURE OPERATIONAL DOCUMENTATION REGARDING WASTE TANK INTERNAL CONFIGURATIONS

The intent of this document is to provide clarification of critical assumptions regarding the internal configurations of liquid waste tanks at operational closure, with respect to F-Tank Farm (FTF) closure documentation. For the purposes of this document, FTF closure documentation includes: (1) Performance Assessment for the F-Tank Farm at the Savannah River Site (hereafter referred to as the FTF PA) (SRS-REG-2007-00002), (2) Basis for Section 3116 Determination for Closure of F-Tank Farm at the Savannah River Site (DOE/SRS-WD-2012-001), (3) Tier 1 Closure Plan for the F-Area Waste Tank Systems at the Savannah River Site (SRR-CWDA-2010-00147), (4) F-Tank Farm Tanks 18 and 19 DOE Manual 435.1-1 Tier 2 Closure Plan Savannah River Site (SRR-CWDA-2011-00015), (5) Industrial Wastewater Closure Module for the Liquid Waste Tanks 18 and 19 (SRRCWDA-2010-00003), and (6) Tank 18/Tank 19 Special Analysis for the Performance Assessment for the F-Tank Farm at the Savannah River Site (hereafter referred to as the Tank 18/Tank 19 Special Analysis) (SRR-CWDA-2010-00124). Note that the first three FTF closure documents listed apply to the entire FTF, whereas the last three FTF closure documents listed are specific to Tanks 18 and 19. These two waste tanks are expected to be the first two tanks to …
Date: March 28, 2012
Creator: Hommel, S. & Fountain, D.
Object Type: Report
System: The UNT Digital Library
Dark Matter Jets at the LHC (open access)

Dark Matter Jets at the LHC

We argue that dark matter particles which have strong interactions with the Standard Model particles are not excluded by current astrophysical constraints. These dark matter particles have unique signatures at colliders; instead of missing energy, the dark matter particles produce jets. We propose a new search strategy for such strongly interacting particles by looking for a signal of two trackless jets. We show that suitable cuts can plausibly allow us to find these signals at the LHC even in early data.
Date: March 28, 2012
Creator: Bai, Yang & Rajaraman, Arvind
Object Type: Article
System: The UNT Digital Library
Effect of Terrestrial and Marine Organic Aerosol on Regional and Global Climate: Model Development, Application, and Verification with Satellite Data (open access)

Effect of Terrestrial and Marine Organic Aerosol on Regional and Global Climate: Model Development, Application, and Verification with Satellite Data

In this DOE project the improvements to parameterization of marine primary organic matter (POM) emissions, hygroscopic properties of marine POM, marine isoprene derived secondary organic aerosol (SOA) emissions, surfactant effects, new cloud droplet activation parameterization have been implemented into Community Atmosphere Model (CAM 5.0), with a seven mode aerosol module from the Pacific Northwest National Laboratory (PNNL)’s Modal Aerosol Model (MAM7). The effects of marine aerosols derived from sea spray and ocean emitted biogenic volatile organic compounds (BVOCs) on microphysical properties of clouds were explored by conducting 10 year CAM5.0-MAM7 model simulations at a grid resolution 1.9°×2.5° with 30 vertical layers. Model-predicted relationship between ocean physical and biological systems and the abundance of CCN in remote marine atmosphere was compared to data from the A-Train satellites (MODIS, CALIPSO, AMSR-E). Model simulations show that on average, primary and secondary organic aerosol emissions from the ocean can yield up to 20% increase in Cloud Condensation Nuclei (CCN) at 0.2% Supersaturation, and up to 5% increases in droplet number concentration of global maritime shallow clouds. Marine organics were treated as internally or externally mixed with sea salt. Changes associated with cloud properties reduced (absolute value) the model-predicted short wave cloud forcing from -1.35 …
Date: March 28, 2012
Creator: Meskhidze, Nicholas; Zhang, Yang & Kamykowski, Daniel
Object Type: Report
System: The UNT Digital Library
An Experimental and Theoretical Investigation of Micropiiting in Wind Turbine Gears and Bearings (open access)

An Experimental and Theoretical Investigation of Micropiiting in Wind Turbine Gears and Bearings

In this research study, the micro-pitting related contact failures of wind turbine gearbox components were investigated both experimentally and theoretically. On the experimental side, a twin-disk type test machine was used to simulate wind turbine transmission contacts in terms of their kinematic (rolling and sliding speeds), surface roughnesses, material parameters and lubricant conditions. A test matrix that represents the ranges of contact conditions of the wind turbine gear boxes was defined and executed to bring an empirical understanding to the micro-pitting problem in terms of key contact parameters and operating conditions. On the theoretical side, the first deterministic micro-pitting model based on a mixed elastohydrodynamic lubrication formulations and multi-axial near-surface crack initiation model was developed. This physics-based model includes actual instantaneous asperity contacts associated with real surface roughness profiles for predicting the onset of the micro-pit formation. The predictions from the theoretical model were compared to the experimental data for validation of the models. The close agreement between the model and measurements was demonstrated. With this, the proposed model can be deemed suitable for identifying the mechanisms leading to micro-pitting of gear and bearing surfaces of wind turbine gear boxes, including all key material, lubricant and surface engineering aspects of …
Date: March 28, 2012
Creator: Kahraman, Ahmet
Object Type: Report
System: The UNT Digital Library
Final Report of Research Conducted For DE-AI02-08ER64546 (open access)

Final Report of Research Conducted For DE-AI02-08ER64546

Research was conducted for 3-4 years to use ARM data to validate satellite cloud retrievals and help the development of improved techniques for remotely sensing clouds and radiative fluxes from space to complement the ARM surface measurement program. This final report summarizes the results and publications during the last 2 years of the studies. Since our last report covering the 2009 period, we published four papers that were accepted during the previous reporting period and revised and published a fifth one. Our efforts to intercalibrate selected channels on several polar orbiting and geostationary satellite imagers, which are funded in part by ASR, resulted in methods that were accepted as part of the international Global Space-based Intercalibration System (GSICS) calibration algorithms. We developed a new empirical method for correcting the spectral differences between comparable channels on various imagers that will be used to correct the calibrations of the satellite data used for ARM. We documented our cloud retrievals for the VAMOS Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-Rex; ARM participated with an AAF contribution) in context of the entire experiment. We used our VOCALS satellite data along with the aircraft measurements to better understand the relationships between aerosols and liquid water path in …
Date: March 28, 2012
Creator: Minnis, Patrick
Object Type: Report
System: The UNT Digital Library
HIGH-DENSITY, BIO-COMPATIBLE, AND HERMETIC ELECTRICAL FEEDTHROUGHS USING EXTRUDED METAL VIAS (open access)

HIGH-DENSITY, BIO-COMPATIBLE, AND HERMETIC ELECTRICAL FEEDTHROUGHS USING EXTRUDED METAL VIAS

Implanted medical devices such as pacemakers and neural prosthetics require that the electronic components that power these devices are protected from the harsh chemical and biological environment of the body. Typically, the electronics are hermetically sealed inside a bio-compatible package containing feedthroughs that transmit electrical signals, while being impermeable to particles or moisture. We present a novel approach for fabricating one of the highest densities of biocompatible hermetic feedthroughs in alumina (Al{sub 2}O{sub 3}). Alumina substrates with laser machined vias of 200 {micro}m pitch were conformally metallized and lithographically patterned. Hermetic electrical feedthroughs were formed by extruding metal stud-bumps partially through the vias. Hermeticity testing showed leak rates better than 9 x 10{sup -10} torr-l/s. Based on our preliminary results and process optimization, this extruded metal via approach is a high-density, low temperature, cost-effective, and robust method of miniaturizing electrical feedthroughs for a wide range of implantable bio-medical device applications.
Date: March 28, 2012
Creator: Shah, K G; Delima, T; Felix, S; Sheth, H; Tolosa, V; Tooker, A et al.
Object Type: Article
System: The UNT Digital Library
Intra-Beam Scattering, Impedance, and Instabilities in Ultimate Storage Rings (open access)

Intra-Beam Scattering, Impedance, and Instabilities in Ultimate Storage Rings

We have investigated collective effects in an ultimate storage ring, i.e. one with diffraction limited emittances in both planes, using PEP-X as an example. In an ultimate ring intra-beam scattering (IBS) sets the limit of current that can be stored. In PEP-X, a 4.5 GeV ring running round beams at 200 mA in 3300 bunches, IBS doubles the emittances to 11.5 pm at the design current. The Touschek lifetime is 11 hours. Impedance driven collective effects tend not to be important since the beam current is relatively low. We have investigated collective effects in PEP-X, an ultimate storage ring, i.e. one with diffraction limited emittances (at one angstrom wavelength) in both planes. In an ultimate ring intra-beam scattering (IBS) sets the limit of current that can be stored. In PEP-X, IBS doubles the emittances to 11.5 pm at the design current of 200 mA, assuming round beams. The Touschek lifetime is quite large in PEP-X, 11.6 hours, and - near the operating point - increases with decreasing emittance. It is, however, a very sensitive function of momentum acceptance. In an ultimate ring like PEP-X impedance driven collective effects tend not to be important since the beam current is relatively low. …
Date: March 28, 2012
Creator: Bane, Karl
Object Type: Article
System: The UNT Digital Library
Joint NMR and Diffraction Studies of Catalyst Structure and Binding (open access)

Joint NMR and Diffraction Studies of Catalyst Structure and Binding

See uploaded final report.
Date: March 28, 2012
Creator: Grey, Clare P.
Object Type: Report
System: The UNT Digital Library
Laser Phase Errors in Seeded FELs (open access)

Laser Phase Errors in Seeded FELs

Harmonic seeding of free electron lasers has attracted significant attention from the promise of transform-limited pulses in the soft X-ray region. Harmonic multiplication schemes extend seeding to shorter wavelengths, but also amplify the spectral phase errors of the initial seed laser, and may degrade the pulse quality. In this paper we consider the effect of seed laser phase errors in high gain harmonic generation and echo-enabled harmonic generation. We use simulations to confirm analytical results for the case of linearly chirped seed lasers, and extend the results for arbitrary seed laser envelope and phase.
Date: March 28, 2012
Creator: Ratner, D.; Fry, A.; Stupakov, G. & White, W.
Object Type: Article
System: The UNT Digital Library
Methanol Synthesis over Cu/ZnO/Al2O3: The Active Site in Industrial Catalysis (open access)

Methanol Synthesis over Cu/ZnO/Al2O3: The Active Site in Industrial Catalysis

Unlike homogeneous catalysts, heterogeneous catalysts that have been optimized through decades are typically so complex and hard to characterize that the nature of the catalytically active site is not known. This is one of the main stumbling blocks in developing rational catalyst design strategies in heterogeneous catalysis. We show here how to identify the crucial atomic structure motif for the industrial Cu/ZnO/Al{sub 2}O{sub 3} methanol synthesis catalyst. Using a combination of experimental evidence from bulk-, surface-sensitive and imaging methods collected on real high-performance catalytic systems in combination with DFT calculations. We show that the active site consists of Cu steps peppered with Zn atoms, all stabilized by a series of well defined bulk defects and surface species that need jointly to be present for the system to work.
Date: March 28, 2012
Creator: Behrens, Malte
Object Type: Article
System: The UNT Digital Library
A RECOMMENDED PASQUILL-GIFFORD STABILITY CLASSIFICATION METHOD FOR SAFETY BASIS ATMOSPHERIC DISPERSION MODELING AT SRS (open access)

A RECOMMENDED PASQUILL-GIFFORD STABILITY CLASSIFICATION METHOD FOR SAFETY BASIS ATMOSPHERIC DISPERSION MODELING AT SRS

Several of the most common methods for estimating Pasquill-Gifford (PG) stability (turbulence) class were evaluated for use in modeling the radiological consequences of SRS accidental releases using the MELCOR Accident Consequence Code System, Ver. 2 (MACCS2). Evaluation criteria included: (1) the ability of the method to represent diffusion characteristics above a predominantly forested landscape at SRS, (2) suitability of the method to provide data consistent with the formulation of the MACCS2 model, and (3) the availability of onsite meteorological data to support implementation of the method The evaluation resulted in a recommendation that PG stability classification for regulatory applications at SRS should be based on measurements of the standard deviation of the vertical component of wind direction fluctuations, {sigma}{sub e}, collected from the 61-m level of the SRS meteorological towers, and processed in full accordance with EPA-454/R-99-005 (EPA, 2000). This approach provides a direct measurement that is fundamental to diffusion and captures explicitly the turbulence generated by both mechanical and buoyant forces over the characteristic surface (forested) of SRS. Furthermore, due to the potentially significant enhancement of horizontal fluctuations in wind direction from the occurrence of meander at night, the use of {sigma}{sub e} will ensure a reasonably conservative estimate …
Date: March 28, 2012
Creator: Hunter, C.
Object Type: Report
System: The UNT Digital Library