Development & Optimization of Materials and Processes for a Cost Effective Photoelectrochemical Hydrogen Production System (open access)

Development & Optimization of Materials and Processes for a Cost Effective Photoelectrochemical Hydrogen Production System

The overall project objective was to apply high throughput experimentation and combinatorial methods together with novel syntheses to discover and optimize efficient, practical, and economically sustainable materials for photoelectrochemical production of bulk hydrogen from water. Automated electrochemical synthesis and photoelectrochemical screening systems were designed and constructed and used to study a variety of new photoelectrocatalytic materials. We evaluated photocatalytic performance in the dark and under illumination with or without applied bias in a high-throughput manner and did detailed evaluation on many materials. Significant attention was given to -Fe2O3 based semiconductor materials and thin films with different dopants were synthesized by co-electrodeposition techniques. Approximately 30 dopants including Al, Zn, Cu, Ni, Co, Cr, Mo, Ti, Pt, etc. were investigated. Hematite thin films doped with Al, Ti, Pt, Cr, and Mo exhibited significant improvements in efficiency for photoelectrochemical water splitting compared with undoped hematite. In several cases we collaborated with theorists who used density functional theory to help explain performance trends and suggest new materials. The best materials were investigated in detail by X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet-visual spectroscopy (UV-Vis), X-ray photoelectron spectroscopy (XPS). The photoelectrocatalytic performance of the thin films was evaluated and their incident photon
Date: January 17, 2011
Creator: McFarland, Eric W.
Object Type: Text
System: The UNT Digital Library
V5 AND V10 CONTACTOR TESTING WITH THE NEXT GENERATION (CSSX) SOLVENT FOR THE SAVANNAH RIVER SITE INTEGRATED SALT DISPOSITION PROCESS (open access)

V5 AND V10 CONTACTOR TESTING WITH THE NEXT GENERATION (CSSX) SOLVENT FOR THE SAVANNAH RIVER SITE INTEGRATED SALT DISPOSITION PROCESS

A solvent extraction system for removal of cesium (Cs) from alkaline solutions was developed utilizing a novel solvent invented at the Oak Ridge National Laboratory (ORNL). This solvent consists of a calix[4]arene-crown-6 extractant dissolved in an inert hydrocarbon matrix. A Modifier is added to the solvent to enhance the extraction power of the calixarene and to prevent the formation of a third phase. An additional additive, called a suppressor, is used to improve stripping performance. The process that deploys this solvent system is known as Caustic Side Solvent Extraction (CSSX). The solvent system has been deployed at the Savannah River Site (SRS) in the Modular CSSX Unit (MCU) since 2008. Subsequent development efforts by ORNL identified an improved solvent system that can raise the expected decontamination factor (DF) in MCU from {approx}200 to more than 40,000. The improved DF is attributed to an improved distribution ratio for cesium [D(Cs)] in extraction from {approx}15 to {approx}60, an increased solubility of the calixarene in the solvent from 0.007 M to >0.050 M, and use of boric acid (H{sub 3}BO{sub 3}) stripping that also yields improved D(Cs) values. Additionally, the changes incorporated into the Next Generation CSSX Solvent (NGS) are intended to reduce …
Date: January 17, 2012
Creator: Restivo, M.; Peters, T.; Pierce, R.; Fondeur, F.; Steeper, T.; Williams, M. et al.
Object Type: Report
System: The UNT Digital Library
Tri-Cities Index of Innovation and Technology (open access)

Tri-Cities Index of Innovation and Technology

In 2001 and 2004, the Economic Development Office of Pacific Northwest National Laboratory published companion reports to the Washington Technology Center Index studies that provided additional information on the Tri-Cities (Kennewick-Richland-Pasco) area of the state, its technology businesses, and important advantages that the Tri-Cities have as places to live and do business. These reports also compared the Tri-Cities area to other technology-based metropolitan areas in the Pacific Northwest and nation along critical dimensions known to be important to technology firms. This report updates the material in these earlier reports, and highlights a growing Tri-Cities metropolitan area.
Date: January 17, 2011
Creator: Fowler, Richard A.; Scott, Michael J. & Butner, Ryan S.
Object Type: Report
System: The UNT Digital Library
Temperature, Humidity, Wind and Pressure Sensors (THWAPS) Handbook (open access)

Temperature, Humidity, Wind and Pressure Sensors (THWAPS) Handbook

The temperature, humidity, wind, and pressure system (THWAPS) provide surface reference values of these measurements for balloon-borne sounding system (SONDE) launches. The THWAPS is located adjacent to the SONDE launch site at the Southern Great Plains (SGP) Central Facility. The THWAPS system is a combination of calibration-quality instruments intended to provide accurate measurements of meteorological conditions near the surface. Although the primary use of the system is to provide accurate surface reference values of temperature, pressure, relative humidity (RH), and wind velocity for comparison with radiosonde readings, the system includes a data logger to record time series of the measured variables.
Date: January 17, 2011
Creator: Ritsche, MT
Object Type: Report
System: The UNT Digital Library
VEGETATION COVER ANALYSIS OF HAZARDOUS WASTE SITES IN UTAH AND ARIZONA USING HYPERSPECTRAL REMOTE SENSING (open access)

VEGETATION COVER ANALYSIS OF HAZARDOUS WASTE SITES IN UTAH AND ARIZONA USING HYPERSPECTRAL REMOTE SENSING

Remote sensing technology can provide a cost-effective tool for monitoring hazardous waste sites. This study investigated the usability of HyMap airborne hyperspectral remote sensing data (126 bands at 2.3 x 2.3 m spatial resolution) to characterize the vegetation at U.S. Department of Energy uranium processing sites near Monticello, Utah and Monument Valley, Arizona. Grass and shrub species were mixed on an engineered disposal cell cover at the Monticello site while shrub species were dominant in the phytoremediation plantings at the Monument Valley site. The specific objectives of this study were to: (1) estimate leaf-area-index (LAI) of the vegetation using three different methods (i.e., vegetation indices, red-edge positioning (REP), and machine learning regression trees), and (2) map the vegetation cover using machine learning decision trees based on either the scaled reflectance data or mixture tuned matched filtering (MTMF)-derived metrics and vegetation indices. Regression trees resulted in the best calibration performance of LAI estimation (R{sup 2} > 0.80). The use of REPs failed to accurately predict LAI (R{sup 2} < 0.2). The use of the MTMF-derived metrics (matched filter scores and infeasibility) and a range of vegetation indices in decision trees improved the vegetation mapping when compared to the decision tree classification …
Date: January 17, 2012
Creator: Serrato, M.; Jungho, I.; Jensen, J.; Jensen, R.; Gladden, J. & Waugh, J.
Object Type: Article
System: The UNT Digital Library
A Note on Neutron Capture Correlation Signals, Backgrounds, and Efficiencies (open access)

A Note on Neutron Capture Correlation Signals, Backgrounds, and Efficiencies

None
Date: January 17, 2012
Creator: Bowden, N; Dazeley, S & Sweany, M
Object Type: Article
System: The UNT Digital Library
Wide Bandgap Extrinsic Photoconductive Switches (open access)

Wide Bandgap Extrinsic Photoconductive Switches

Photoconductive semiconductor switches (PCSS) have been investigated since the late 1970s. Some devices have been developed that withstand tens of kilovolts and others that switch hundreds of amperes. However, no single device has been developed that can reliably withstand both high voltage and switch high current. Yet, photoconductive switches still hold the promise of reliable high voltage and high current operation with subnanosecond risetimes. Particularly since good quality, bulk, single crystal, wide bandgap semiconductor materials have recently become available. In this chapter we will review the basic operation of PCSS devices, status of PCSS devices and properties of the wide bandgap semiconductors 4H-SiC, 6H-SiC and 2H-GaN.
Date: January 17, 2012
Creator: Sullivan, J S
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Creep Rupture Testing of Alloy 617 and A508/533 Base Metals and Weldments. (open access)

Creep Rupture Testing of Alloy 617 and A508/533 Base Metals and Weldments.

The NGNP, which is an advanced HTGR concept with emphasis on both electricity and hydrogen production, involves helium as the coolant and a closed-cycle gas turbine for power generation with a core outlet/gas turbine inlet temperature of 750-1000 C. Alloy 617 is a prime candidate for VHTR structural components such as reactor internals, piping, and heat exchangers in view of its resistance to oxidation and elevated temperature strength. However, lack of adequate data on the performance of the alloy in welded condition prompted to initiate a creep test program at Argonne National Laboratory. In addition, Testing has been initiated to evaluate the creep rupture properties of the pressure vessel steel A508/533 in air and in helium environments. The program, which began in December 2009, was certified for quality assurance NQA-1 requirements during January and February 2010. Specimens were designed and fabricated during March and the tests were initiated in April 2010. During the past year, several creep tests were conducted in air on Alloy 617 base metal and weldment specimens at temperatures of 750, 850, and 950 C. Idaho National Laboratory, using gas tungsten arc welding method with Alloy 617 weld wire, fabricated the weldment specimens. Eight tests were conducted …
Date: January 17, 2012
Creator: Natesan, K.; Li, M.; Soppet, W.K. & Rink, D.L. (Nuclear Engineering Division)
Object Type: Report
System: The UNT Digital Library
Field Campaign Guidelines (ARM Climate Research Facility) (open access)

Field Campaign Guidelines (ARM Climate Research Facility)

The purpose of this document is to establish a common set of guidelines for the Atmospheric Radiation Measurement (ARM) Climate Research Facility for planning, executing, and closing out field campaigns. The steps that guide individual field campaigns are described in the Field Campaign Tracking database tool and are tailored to meet the scope of each specific field campaign.
Date: January 17, 2011
Creator: Voyles, JW
Object Type: Text
System: The UNT Digital Library
Radiation Protection Aspects in the Design of the Linac Coherent Light Source II (open access)

Radiation Protection Aspects in the Design of the Linac Coherent Light Source II

None
Date: January 17, 2013
Creator: Santana Leitner, Mario; Liu, James C.; Mao, Stan X.; Nicolas, Ludovic; Rokni, Sayed H. & Xiao, Shanjie
Object Type: Report
System: The UNT Digital Library
LED Surgical Task Lighting Scoping Study: A Hospital Energy Alliance Project (open access)

LED Surgical Task Lighting Scoping Study: A Hospital Energy Alliance Project

Tungsten-halogen (halogen) lamps have traditionally been used to light surgical tasks in hospitals, even though they are in many respects ill-suited to the application due to the large percentage of radiant energy outside the visible spectrum and issues with color rendering/quality. Light-emitting diode (LED) technology offers potential for adjustable color and improved color rendition/quality, while simultaneously reducing side-effects from non-visible radiant energy. It also has the potential for significant energy savings, although this is a fairly narrow application in the larger commercial building energy use sector. Based on analysis of available products and Hospital Energy Alliance member interest, it is recommended that a product specification and field measurement procedure be developed for implementation in demonstration projects.
Date: January 17, 2011
Creator: Tuenge, Jason R.
Object Type: Report
System: The UNT Digital Library
UV Laser Radiation: Skin Hazards and Skin Protection Controls (open access)

UV Laser Radiation: Skin Hazards and Skin Protection Controls

None
Date: January 17, 2013
Creator: Corbett, Jeff & Woods, Michael
Object Type: Article
System: The UNT Digital Library
A One System Integrated Approach to Simulant Selection for Hanford High Level Waste Mixing and Sampling Tests (open access)

A One System Integrated Approach to Simulant Selection for Hanford High Level Waste Mixing and Sampling Tests

The Hanford Tank Operations Contractor (TOC) and the Hanford Waste Treatment and Immobilization Plant (WTP) contractor are both engaged in demonstrating mixing, sampling, and transfer system capabilities using simulated Hanford High-Level Waste (HLW) formulations. This represents one of the largest remaining technical issues with the high-level waste treatment mission at Hanford. Previous testing has focused on very specific TOC or WTP test objectives and consequently the simulants were narrowly focused on those test needs. A key attribute in the Defense Nuclear Facilities Safety Board (DNFSB) Recommendation 2010-2 is to ensure testing is performed with a simulant that represents the broad spectrum of Hanford waste. The One System Integrated Project Team is a new joint TOC and WTP organization intended to ensure technical integration of specific TOC and WTP systems and testing. A new approach to simulant definition has been mutually developed that will meet both TOC and WTP test objectives for the delivery and receipt of HLW. The process used to identify critical simulant characteristics, incorporate lessons learned from previous testing, and identify specific simulant targets that ensure TOC and WTP testing addresses the broad spectrum of Hanford waste characteristics that are important to mixing, sampling, and transfer performance are …
Date: January 17, 2013
Creator: Thien, Mike G. & Barnes, Steve M.
Object Type: Article
System: The UNT Digital Library
ARM Climate Research Facility Quarterly Instrument Report Fourth Quarter: October 1–December 30, 2010 (open access)

ARM Climate Research Facility Quarterly Instrument Report Fourth Quarter: October 1–December 30, 2010

The purpose of this report is to provide a concise but comprehensive overview of Atmospheric Radiation Measurement Climate Research Facility instrumentation status. The report is divided into the following sections: (1) new instrumentation in the process of being acquired and deployed, (2) existing instrumentation and progress on improvements or upgrades, (3) proposed future instrumentation, and (4) Small Business Innovation Research instrument development.
Date: January 17, 2011
Creator: Voyles, JW
Object Type: Report
System: The UNT Digital Library
Harnessing the Department of Energy’s High-Performance Computing Expertise to Strengthen the U.S. Chemical Enterprise (open access)

Harnessing the Department of Energy’s High-Performance Computing Expertise to Strengthen the U.S. Chemical Enterprise

High-performance computing (HPC) is one area where the DOE has developed extensive expertise and capability. However, this expertise currently is not properly shared with or used by the private sector to speed product development, enable industry to move rapidly into new areas, and improve product quality. Such use would lead to substantial competitive advantages in global markets and yield important economic returns for the United States. To stimulate the dissemination of DOE's HPC expertise, the Council for Chemical Research (CCR) and the DOE jointly held a workshop on this topic. Four important energy topic areas were chosen as the focus of the meeting: Biomass/Bioenergy, Catalytic Materials, Energy Storage, and Photovoltaics. Academic, industrial, and government experts in these topic areas participated in the workshop to identify industry needs, evaluate the current state of expertise, offer proposed actions and strategies, and forecast the expected benefits of implementing those strategies.
Date: January 17, 2012
Creator: Dixon, David A.; Dupuis, Michel; Garrett, Bruce C.; Neaton, Jeffrey B.; Plata, Charity; Tarr, Matthew A. et al.
Object Type: Report
System: The UNT Digital Library
Performance Metrics for Safe Laser Operations at SLAC National Accelerator Laboratory (open access)

Performance Metrics for Safe Laser Operations at SLAC National Accelerator Laboratory

None
Date: January 17, 2013
Creator: Woods, Michael
Object Type: Article
System: The UNT Digital Library
An Accurate Model of Beam Ion Instability with Nonlinear Space Charge, Realistic Beam Optics and Multiple Gas Species Vacuum (open access)

An Accurate Model of Beam Ion Instability with Nonlinear Space Charge, Realistic Beam Optics and Multiple Gas Species Vacuum

None
Date: January 17, 2013
Creator: Wang, L.; Pivi, M.; Raubenheimer, T. O. & Safranek, J.
Object Type: Report
System: The UNT Digital Library
Multi-Objective Optimization for the National Ignition Facility's Gamma Reaction History Diagnostic (open access)

Multi-Objective Optimization for the National Ignition Facility's Gamma Reaction History Diagnostic

None
Date: January 17, 2013
Creator: Labaria, G R; Liebman, J A; Sayre, D B; Herrmann, H W; Bond, E J & Church, J A
Object Type: Article
System: The UNT Digital Library
Quantum mechanical approaches to in silico enzyme characterization and drug design (open access)

Quantum mechanical approaches to in silico enzyme characterization and drug design

The astonishing, exponentially increasing rates of genome sequencing has led to one of the most significant challenges for the biological and computational sciences in the 21st century: assigning the likely functions of the encoded proteins. Enzymes represent a particular challenge, and a critical one, because the universe of enzymes is likely to contain many novel functions that may be useful for synthetic biology, or as drug targets. Current approaches to protein annotation are largely based on bioinformatics. At the simplest level, this annotation involves transferring the annotations of characterized enzymes to related sequences. In practice, however, there is no simple, sequence based criterion for transferring annotations, and bioinformatics alone cannot propose new enzymatic functions. Structure-based computational methods have the potential to address these limitations, by identifying potential substrates of enzymes, as we and others have shown. One successful approach has used in silico 'docking' methods, more commonly applied in structure-based drug design, to identify possible metabolite substrates. A major limitation of this approach is that it only considers substrate binding, and does not directly assess the potential of the enzyme to catalyze a particular reaction using a particular substrate. That is, substrate binding affinity is necessary but not sufficient to …
Date: January 17, 2012
Creator: Nilmeier, J P; Fattebert, J L; Jacobson, M P & Kalyanaraman, C
Object Type: Report
System: The UNT Digital Library
Post-Closure Report for Closed Resource Conservation and Recovery Act Corrective Action Units, Nevada National Security Site, Nevada For Fiscal Year 2012 (October 2011–September 2012) (open access)

Post-Closure Report for Closed Resource Conservation and Recovery Act Corrective Action Units, Nevada National Security Site, Nevada For Fiscal Year 2012 (October 2011–September 2012)

This report serves as the combined annual report for post-closure activities for the following closed Corrective Action Units (CAUs): · CAU 90, Area 2 Bitcutter Containment · CAU 91, Area 3 U-3fi Injection Well · CAU 92, Area 6 Decon Pond Facility · CAU 110, Area 3 WMD U-3ax/bl Crater · CAU 111, Area 5 WMD Retired Mixed Waste Pits · CAU 112, Area 23 Hazardous Waste Trenches This report covers fiscal year 2012 (October 2011–September 2012).
Date: January 17, 2013
Creator: National Security Technologies, LLC
Object Type: Report
System: The UNT Digital Library
Aerosol Observing System (AOS) Handbook (open access)

Aerosol Observing System (AOS) Handbook

The Aerosol Observing System (AOS) is a suite of in situ surface measurements of aerosol optical and cloud-forming properties. The instruments measure aerosol properties that influence the earth’s radiative balance. The primary optical measurements are those of the aerosol scattering and absorption coefficients as a function of particle size and radiation wavelength and cloud condensation nuclei (CCN) measurements as a function of percent supersaturation. Additional measurements include those of the particle number concentration and scattering hygroscopic growth. Aerosol optical measurements are useful for calculating parameters used in radiative forcing calculations such as the aerosol single-scattering albedo, asymmetry parameter, mass scattering efficiency, and hygroscopic growth. CCN measurements are important in cloud microphysical models to predict droplet formation.
Date: January 17, 2011
Creator: Jefferson, A
Object Type: Report
System: The UNT Digital Library
Multi-unit Operations in Non-Nuclear Systems: Lessons Learned for Small Modular Reactors (open access)

Multi-unit Operations in Non-Nuclear Systems: Lessons Learned for Small Modular Reactors

The nuclear-power community has reached the stage of proposing advanced reactor designs to support power generation for decades to come. Small modular reactors (SMRs) are one approach to meet these energy needs. While the power output of individual reactor modules is relatively small, they can be grouped to produce reactor sites with different outputs. Also, they can be designed to generate hydrogen, or to process heat. Many characteristics of SMRs are quite different from those of current plants and may be operated quite differently. One difference is that multiple units may be operated by a single crew (or a single operator) from one control room. The U.S. Nuclear Regulatory Commission (NRC) is examining the human factors engineering (HFE) aspects of SMRs to support licensing reviews. While we reviewed information on SMR designs to obtain information, the designs are not completed and all of the design and operational information is not yet available. Nor is there information on multi-unit operations as envisioned for SMRs available in operating experience. Thus, to gain a better understanding of multi-unit operations we sought the lesson learned from non-nuclear systems that have experience in multi-unit operations, specifically refineries, unmanned aerial vehicles and tele-intensive care units. In …
Date: January 17, 2012
Creator: Ohara, J. M.; Higgins, J. & DAgostino, A.
Object Type: Article
System: The UNT Digital Library
Cimel Sunphotometer (CSPHOT) Handbook (open access)

Cimel Sunphotometer (CSPHOT) Handbook

The Cimel sunphotometer (CSPHOT) is a multi-channel, automatic sun-and-sky scanning radiometer that measures the direct solar irradiance and sky radiance at the Earth’s surface. Measurements are taken at pre-determined discrete wavelengths in the visible and near-IR parts of the spectrum to determine atmospheric transmission and scattering properties. This instrument is weather-proof and requires little maintenance during periods of adverse weather conditions. It takes measurements only during daylight hours (sun above horizon).
Date: January 17, 2011
Creator: Gregory, L
Object Type: Report
System: The UNT Digital Library
NEXT GENERATION SOLVENT-MATERIALS COMPATIBILITY WITH POLYMER COMPONENTS WITHIN MODULAR CAUSTIC-SIDE SOLVENT EXTRACTION UNIT (FINAL REPORT) (open access)

NEXT GENERATION SOLVENT-MATERIALS COMPATIBILITY WITH POLYMER COMPONENTS WITHIN MODULAR CAUSTIC-SIDE SOLVENT EXTRACTION UNIT (FINAL REPORT)

The Office of Waste Processing, within the Office of Technology Innovation and Development, is funding the development of an enhanced solvent for deployment at the Savannah River Site for removal of cesium from High Level Waste. The technical effort is collaboration between Oak Ridge National Laboratory (ORNL), Savannah River National Laboratory (SRNL), and Argonne National Laboratory. The first deployment target for the technology is within the Modular Caustic-Side Solvent Extraction Unit (MCU). Deployment of a new chemical within an existing facility requires verification that the chemical components are compatible with the installed equipment. In the instance of a new organic solvent, the primary focus is on compatibility of the solvent with organic polymers used in the facility. This report provides the data from exposing these polymers to the Next Generation Solvent (NGS). The test was conducted over six months. An assessment of the dimensional stability of polymers present in MCU (i.e., PEEK, Grafoil, Tefzel and Isolast) in the modified NGS (where the concentration of LIX{reg_sign}79 and MaxCalix was varied systematically) showed that LIX{reg_sign}79 selectively affected Tefzel and its different grades (by an increase in size and lowering its density). The copolymer structure of Tefzel and possibly its porosity allows for …
Date: January 17, 2012
Creator: Fondeur, F.; Peters, T. & Fink, S.
Object Type: Report
System: The UNT Digital Library