Energy Saving Melting and Revert Reduction Technology: Aging of Graphitic Cast Irons and Machinability (open access)

Energy Saving Melting and Revert Reduction Technology: Aging of Graphitic Cast Irons and Machinability

The objective of this task was to determine whether ductile iron and compacted graphite iron exhibit age strengthening to a statistically significant extent. Further, this effort identified the mechanism by which gray iron age strengthens and the mechanism by which age-strengthening improves the machinability of gray cast iron. These results were then used to determine whether age strengthening improves the machinability of ductile iron and compacted graphite iron alloys in order to develop a predictive model of alloy factor effects on age strengthening. The results of this work will lead to reduced section sizes, and corresponding weight and energy savings. Improved machinability will reduce scrap and enhance casting marketability. Technical Conclusions: • Age strengthening was demonstrated to occur in gray iron ductile iron and compacted graphite iron. • Machinability was demonstrated to be improved by age strengthening when free ferrite was present in the microstructure, but not in a fully pearlitic microstructure. • Age strengthening only occurs when there is residual nitrogen in solid solution in the Ferrite, whether the ferrite is free ferrite or the ferrite lamellae within pearlite. • Age strengthening can be accelerated by Mn at about 0.5% in excess of the Mn/S balance Estimated energy savings …
Date: September 19, 2012
Creator: Richards, Von L.
Object Type: Report
System: The UNT Digital Library
Summary of operations and performance of the Utica aquifer and North Lake Basin Wetlands restoration project in December 2010-November 2011. (open access)

Summary of operations and performance of the Utica aquifer and North Lake Basin Wetlands restoration project in December 2010-November 2011.

None
Date: September 19, 2012
Creator: LaFreniere, L. M.
Object Type: Report
System: The UNT Digital Library
Fiber Lasers X: Technology, Systems and Aplications (open access)

Fiber Lasers X: Technology, Systems and Aplications

None
Date: July 19, 2012
Creator: Drachenberg, D
Object Type: Article
System: The UNT Digital Library
Linac Alignment Algorithm: Analysis on 1-to-1 Steering (open access)

Linac Alignment Algorithm: Analysis on 1-to-1 Steering

In a linear accelerator, it is important to achieve a good alignment between all of its components (such as quadrupoles, RF cavities, beam position monitors et al.), in order to better preserve the beam quality during acceleration. After the survey of the main linac components, there are several beam-based alignment (BBA) techniques to be applied, to further optimize the beam trajectory and calculate the corresponding steering magnets strength. Among these techniques the most simple and straightforward one is the one-to-one (1-to-1) steering technique, which steers the beam from quad center to center, and removes the betatron oscillation from quad focusing. For a future linear collider such as the International Linear Collider (ILC), the initial beam emittance is very small in the vertical plane (flat beam with {gamma}{epsilon}{sub y} = 20-40nm), which means the alignment requirement is very tight. In this note, we evaluate the emittance growth with one-to-one correction algorithm employed, both analytically and numerically. Then the ILC main linac accelerator is taken as an example to compare the vertical emittance growth after 1-to-1 steering, both from analytical formulae and multi-particle tracking simulation. It is demonstrated that the estimated emittance growth from the derived formulae agrees well with the results …
Date: August 19, 2011
Creator: Sun, Yipeng & Adolphsen, Chris
Object Type: Report
System: The UNT Digital Library
Emittance and Phase Space Exchange (open access)

Emittance and Phase Space Exchange

Alternative chicane-type beam lines are proposed for exact emittance exchange between horizontal phase space (x; x{prime}) and longitudinal phase space (z; {delta}). Methods to achieve exact phase space exchanges, i.e. mapping x to z, x{prime} to {delta}, z to x and {delta} to x{prime} are suggested. Methods to mitigate the thick-lens effect of the transverse cavity on emittance exchange are discussed. Some applications of the phase space exchanger and the feasibility of an emittance exchange experiment with the proposed chicane-type beam line at SLAC are discussed.
Date: August 19, 2011
Creator: Xiang, Dao & Chao, Alex
Object Type: Article
System: The UNT Digital Library
Density Functional Theory in Surface Chemistry and Catalysis (open access)

Density Functional Theory in Surface Chemistry and Catalysis

Recent advances in the understanding of reactivity trends for chemistry at transition metal surfaces have enabled in silico design of heterogeneous catalysts in a few cases. Current status of the field is discussed with an emphasis on the role of coupling between theory and experiment and future challenges.
Date: May 19, 2011
Creator: Norskov, Jens
Object Type: Article
System: The UNT Digital Library
Fully Integrated Applications of Thin Films on Low Temperature Cofired Ceramic (LTCC) (open access)

Fully Integrated Applications of Thin Films on Low Temperature Cofired Ceramic (LTCC)

Thin film multilayers have previously been introduced on multilayer low temperature cofired ceramic (LTCC), as well as initial thin film capacitors on LTCC. The ruggedness of a multipurpose Ti-Cu-Pt-Au stack for connectivity and RF conductivity has continued to benefit fabrication and reliability in state of-the-art modules, while the capacitors have followed the traditional Metal-Insulator-Metal (MIM) style. The full integration of thin film passives with thin film connectivity traces is presented. Certain passives, such as capacitors, require specifically tailored and separately patterned thin film (multi-)layers, including a dielectric. Different capacitance values are achieved by variation of both the insulator layer thickness and the active area of the capacitor. Other passives, such as filters, require only the conductor - a single thin film multilayer. This can be patterned from the same connectivity thin film material (Ti-Cu-Pt-Au), or a specially tailored thin film material (e.g. Ti-Cu-Au) can be deposited. Both versions are described, including process and integration details. Examples are discussed, ranging from patterning for maximum tolerances, to space and performance-optimized designs. Cross-sectional issues associated with integration are also highlighted in the discussion.
Date: April 19, 2012
Creator: Wolf, Ambrose; Peterson, Ken; O'Keefe, Matt; Huebner, Wayne & Kuhn, Bill
Object Type: Article
System: The UNT Digital Library
Super symmetry Without Prejudice at the LHC (open access)

Super symmetry Without Prejudice at the LHC

The discovery and exploration of Supersymmetry in a model-independent fashion will be a daunting task due to the large number of soft-breaking parameters in the MSSM. In this paper, we explore the capability of the ATLAS detector at the LHC ({radical}s = 14 TeV, 1 fb{sup -1}) to find SUSY within the 19-dimensional pMSSM subspace of the MSSM using their standard transverse missing energy and long-lived particle searches that were essentially designed for mSUGRA. To this end, we employ a set of {approx} 71k previously generated model points in the 19-dimensional parameter space that satisfy all of the existing experimental and theoretical constraints. Employing ATLAS-generated SM backgrounds and following their approach in each of 11 missing energy analyses as closely as possible, we explore all of these 71k model points for a possible SUSY signal. To test our analysis procedure, we first verify that we faithfully reproduce the published ATLAS results for the signal distributions for their benchmark mSUGRA model points. We then show that, requiring all sparticle masses to lie below 1(3) TeV, almost all(two-thirds) of the pMSSM model points are discovered with a significance S > 5 in at least one of these 11 analyses assuming a 50% …
Date: August 19, 2011
Creator: Conley, John A.; Gainer, James S.; Hewett, JoAnne L.; Le, My Phuong & Rizzo, Thomas G.
Object Type: Article
System: The UNT Digital Library
Hollow-Core Photonic Band Gap Fibers for Particle Acceleration (open access)

Hollow-Core Photonic Band Gap Fibers for Particle Acceleration

Photonic band gap (PBG) dielectric fibers with hollow cores are being studied both theoretically and experimentally for use as laser driven accelerator structures. The hollow core functions as both a longitudinal waveguide for the transverse-magnetic (TM) accelerating fields and a channel for the charged particles. The dielectric surrounding the core is permeated by a periodic array of smaller holes to confine the mode, forming a photonic crystal fiber in which modes exist in frequency pass-bands, separated by band gaps. The hollow core acts as a defect which breaks the crystal symmetry, and so-called defect, or trapped modes having frequencies in the band gap will only propagate near the defect. We describe the design of 2-D hollow-core PBG fibers to support TM defect modes with high longitudinal fields and high characteristic impedance. Using as-built dimensions of industrially-made fibers, we perform a simulation analysis of the first prototype PBG fibers specifically designed to support speed-of-light TM modes.
Date: August 19, 2011
Creator: Noble, Robert J.; Spencer, James E. & Kuhlmey, Boris T.
Object Type: Article
System: The UNT Digital Library
Improved Space Charge Modeling for Simulation and Design of Photoinjectors (open access)

Improved Space Charge Modeling for Simulation and Design of Photoinjectors

Photoinjectors in advanced high-energy accelerators reduce beam energy spreads and enhance undulator photon fluxes. Photoinjector design is difficult because of the substantial differences in time and spatial scales. This Phase I program explored an innovative technique, the local Taylor polynomial (LTP) formulation, for improving finite difference analysis of photoinjectors. This included improved weighting techniques, systematic formula for high order interpolation and electric field computation, and improved handling of space charge. The Phase I program demonstrated that the approach was powerful, accurate, and efficient. It handles space charge gradients better than currently available technology.
Date: April 19, 2010
Creator: Robert H. Jackson, Thuc Bui, John Verboncoeur
Object Type: Report
System: The UNT Digital Library
Numerical Modeling of 90Sr and 137Cs Transport from a Spill in the B-Cell of the 324 Building, Hanford Site 300 Area (open access)

Numerical Modeling of 90Sr and 137Cs Transport from a Spill in the B-Cell of the 324 Building, Hanford Site 300 Area

To characterize the extent of contamination under the 324 Building, a pit was excavated on the north side of the building in 2010 by Washington Closure Hanford LLC (WCH). Horizontal closed-end steel access pipes were installed under the foundation of the building from this pit and were used for measuring temperatures and exposure rates under the B-Cell. The deployed sensors measured elevated temperatures of up to 61 C (142 F) and exposure rates of up to 8,900 R/hr. WCH suspended deactivation of the facility because it recognized that building safety systems and additional characterization data might be needed for remediation of the contaminated material. The characterization work included additional field sampling, laboratory measurements, and numerical flow and transport modeling. Laboratory measurements of sediment physical, hydraulic, and geochemical properties were performed by Pacific Northwest National Laboratory (PNNL) and others. Geochemical modeling and subsurface flow and transport modeling also were performed by PNNL to evaluate the possible extent of contamination in the unsaturated sand and gravel sediments underlying the building. Historical records suggest that the concentrated 137Cs- and 90Sr-bearing liquid wastes that were spilled in B-Cell were likely from a glass-waste repository testing program associated with the Federal Republic of Germany (FRG). …
Date: March 19, 2012
Creator: Rockhold, Mark L.; Bacon, Diana H.; Freedman, Vicky L.; Lindberg, Michael J. & Clayton, Ray E.
Object Type: Report
System: The UNT Digital Library
Techniques for correcting velocity and density fluctuations of ion beams (open access)

Techniques for correcting velocity and density fluctuations of ion beams

None
Date: June 19, 2012
Creator: Woo, K. M.; Yu, S. S. & Barnard, J. J.
Object Type: Article
System: The UNT Digital Library
Electrodeposition of U and Pu on Thin C and Ti Substrates (open access)

Electrodeposition of U and Pu on Thin C and Ti Substrates

Physics experiments aimed at deducing key parameters for use in a variety of programs critical to the mission of the National Laboratories require actinide targets placed onto various substrates. The target material quantity and the substrate desired depend upon the type of experiment being designed. The physicist(s) responsible for the experimental campaign will consult with the radiochemistry staff as to the feasibility of producing a desired target/substrate combination. In this report they discuss the production of U and Pu targets on very thin C and Ti substrates. The techniques used, plating cells designed for, tips, and limits is discussed.
Date: May 19, 2010
Creator: Henderson, R. A. & Gostic, J. M.
Object Type: Article
System: The UNT Digital Library
Optimization of the safety factor profile for high noninductive current fraction discharges in DIII-D (open access)

Optimization of the safety factor profile for high noninductive current fraction discharges in DIII-D

None
Date: January 19, 2011
Creator: Ferron, J.; Holcomb, C.; Luce, T.; Politzer, P.; Turco, F.; White, A. et al.
Object Type: Article
System: The UNT Digital Library
National Emission Standards for Hazardous Air Pollutants - Radionuclide Emissions, Calendar Year 2011 (open access)

National Emission Standards for Hazardous Air Pollutants - Radionuclide Emissions, Calendar Year 2011

The U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office operates the Nevada National Security Site (NNSS) and North Las Vegas Facility (NLVF). From 1951 through 1992, the NNSS was the continental testing location for U.S. nuclear weapons. The release of radionuclides from NNSS activities has been monitored since the initiation of atmospheric testing. Limitation to underground detonations after 1962 greatly reduced radiation exposure to the public surrounding the NNSS. After nuclear testing ended in 1992, NNSS radiation monitoring focused on detecting airborne radionuclides from historically contaminated soils. These radionuclides are derived from re-suspension of soil (primarily by wind) and emission of tritium-contaminated soil moisture through evapotranspiration. Low amounts of legacy-related tritium are also emitted to air at the NLVF, an NNSS support complex in North Las Vegas. To protect the public from harmful levels of man-made radiation, the Clean Air Act, National Emission Standards for Hazardous Air Pollutants (NESHAP) (Title 40 Code of Federal Regulations [CFR] Part 61 Subpart H) limits the release of radioactivity from a U.S. Department of Energy (DOE) facility to that which would cause 10 millirem per year (mrem/yr) effective dose equivalent to any member of the public. This limit does not include …
Date: June 19, 2012
Creator: Monitoring, NSTec Ecological and Environmental
Object Type: Report
System: The UNT Digital Library
Tank 40 Final Sludge Batch 8 Chemical Characterization Results (open access)

Tank 40 Final Sludge Batch 8 Chemical Characterization Results

A sample of Sludge Batch 8 (SB8) was pulled from Tank 40 in order to obtain radionuclide inventory analyses necessary for compliance with the Waste Acceptance Product Specifications (WAPS). The SB8 WAPS sample was also analyzed for chemical composition, including noble metals, and fissile constituents, and these results are reported here. These analyses along with the WAPS radionuclide analyses will help define the composition of the sludge in Tank 40 that is currently being fed to the Defense Waste Processing Facility (DWPF) as SB8. At SRNL, the 3-L Tank 40 SB8 sample was transferred from the shipping container into a 4-L high density polyethylene bottle and solids were allowed to settle. Supernate was then siphoned off and circulated through the shipping container to complete the transfer of the sample. Following thorough mixing of the 3-L sample, a 553 g sub-sample was removed. This sub-sample was then utilized for all subsequent slurry sample preparations. Eight separate aliquots of the slurry were digested, four with HNO{sub 3}/HCl (aqua regia) in sealed Teflon(r) vessels and four with NaOH/Na{sub 2}O{sub 2} (alkali or peroxide fusion) using Zr crucibles. Two Analytical Reference Glass - 1 (ARG-1) standards were digested along with a blank for each …
Date: September 19, 2013
Creator: Bannochie, Christopher J.
Object Type: Report
System: The UNT Digital Library
Radioactive Waste Conditioning, Immobilisation, And Encapsulation Processes And Technologies: Overview And Advances (Chapter 7) (open access)

Radioactive Waste Conditioning, Immobilisation, And Encapsulation Processes And Technologies: Overview And Advances (Chapter 7)

The main immobilization technologies that are available commercially and have been demonstrated to be viable are cementation, bituminization, and vitrification. Vitrification is currently the most widely used technology for the treatment of high level radioactive wastes (HLW) throughout the world. Most of the nations that have generated HLW are immobilizing in either alkali borosilicate glass or alkali aluminophosphate glass. The exact compositions of nuclear waste glasses are tailored for easy preparation and melting, avoidance of glass-in-glass phase separation, avoidance of uncontrolled crystallization, and acceptable chemical durability, e.g., leach resistance. Glass has also been used to stabilize a variety of low level wastes (LLW) and mixed (radioactive and hazardous) low level wastes (MLLW) from other sources such as fuel rod cladding/decladding processes, chemical separations, radioactive sources, radioactive mill tailings, contaminated soils, medical research applications, and other commercial processes. The sources of radioactive waste generation are captured in other chapters in this book regarding the individual practices in various countries (legacy wastes, currently generated wastes, and future waste generation). Future waste generation is primarily driven by interest in sources of clean energy and this has led to an increased interest in advanced nuclear power production. The development of advanced wasteforms is a …
Date: October 19, 2012
Creator: Jantzen, Carol M.; Lee, William E. & Ojovan, Michael I.
Object Type: Book
System: The UNT Digital Library
Solar Thermochemical Fuels Production: Solar Thermochemical Fuel Production via a Novel Lowe Pressure, Magnetically Stabilized, Non-volatile Iron Oxide Looping Process (open access)

Solar Thermochemical Fuels Production: Solar Thermochemical Fuel Production via a Novel Lowe Pressure, Magnetically Stabilized, Non-volatile Iron Oxide Looping Process

HEATS Project: The University of Florida is developing a windowless high-temperature chemical reactor that converts concentrated solar thermal energy to syngas, which can be used to produce gasoline. The overarching project goal is lowering the cost of the solar thermochemical production of syngas for clean and synthetic hydrocarbon fuels like petroleum. The team will develop processes that rely on water and recycled CO2 as the sole feed-stock, and concentrated solar radiation as the sole energy source, to power the reactor to produce fuel efficiently. Successful large-scale deployment of this solar thermochemical fuel production could substantially improve our national and economic security by replacing imported oil with domestically produced solar fuels.
Date: December 19, 2011
Creator: unknown
Object Type: Text
System: The UNT Digital Library
Requirements for Defining Utility Drive Cycles: An Exploratory Analysis of Grid Frequency Regulation Data for Establishing Battery Performance Testing Standards (open access)

Requirements for Defining Utility Drive Cycles: An Exploratory Analysis of Grid Frequency Regulation Data for Establishing Battery Performance Testing Standards

Battery testing procedures are important for understanding battery performance, including degradation over the life of the battery. Standards are important to provide clear rules and uniformity to an industry. The work described in this report addresses the need for standard battery testing procedures that reflect real-world applications of energy storage systems to provide regulation services to grid operators. This work was motivated by the need to develop Vehicle-to-Grid (V2G) testing procedures, or V2G drive cycles. Likewise, the stationary energy storage community is equally interested in standardized testing protocols that reflect real-world grid applications for providing regulation services. As the first of several steps toward standardizing battery testing cycles, this work focused on a statistical analysis of frequency regulation signals from the Pennsylvania-New Jersey-Maryland Interconnect with the goal to identify patterns in the regulation signal that would be representative of the entire signal as a typical regulation data set. Results from an extensive time-series analysis are discussed, and the results are explained from both the statistical and the battery-testing perspectives. The results then are interpreted in the context of defining a small set of V2G drive cycles for standardization, offering some recommendations for the next steps toward standardizing testing protocols.
Date: October 19, 2011
Creator: Hafen, Ryan P.; Vishwanathan, Vilanyur V.; Subbarao, Krishnappa & Kintner-Meyer, Michael CW
Object Type: Report
System: The UNT Digital Library
Parametric Explosion Spectral Model (open access)

Parametric Explosion Spectral Model

Small underground nuclear explosions need to be confidently detected, identified, and characterized in regions of the world where they have never before occurred. We develop a parametric model of the nuclear explosion seismic source spectrum derived from regional phases that is compatible with earthquake-based geometrical spreading and attenuation. Earthquake spectra are fit with a generalized version of the Brune spectrum, which is a three-parameter model that describes the long-period level, corner-frequency, and spectral slope at high-frequencies. Explosion spectra can be fit with similar spectral models whose parameters are then correlated with near-source geology and containment conditions. We observe a correlation of high gas-porosity (low-strength) with increased spectral slope. The relationship between the parametric equations and the geologic and containment conditions will assist in our physical understanding of the nuclear explosion source.
Date: January 19, 2012
Creator: Ford, S R & Walter, W R
Object Type: Report
System: The UNT Digital Library
The One-Loop Six-Dimensional Hexagon Integral and its Relation to MHV Amplitudes in N=4 SYM (open access)

The One-Loop Six-Dimensional Hexagon Integral and its Relation to MHV Amplitudes in N=4 SYM

We provide an analytic formula for the (rescaled) one-loop scalar hexagon integral {tilde {Phi}}{sub 6} with all external legs massless, in terms of classical polylogarithms. We show that this integral is closely connected to two integrals appearing in one- and two-loop amplitudes in planar N = 4 super-Yang-Mills theory, {Omega}{sup (1)} and {Omega}{sup (2)}. The derivative of {Omega}{sup (2)} with respect to one of the conformal invariants yields {tilde {Phi}}{sub 6}, while another first-order differential operator applied to {tilde {Phi}}{sub 6} yields {Omega}{sup (1)}. We also introduce some kinematic variables that rationalize the arguments of the polylogarithms, making it easy to verify the latter differential equation. We also give a further example of a six-dimensional integral relevant for amplitudes in N = 4 super-Yang-Mills.
Date: August 19, 2011
Creator: Dixon, Lance J.; Drummond, James M. & Henn, Johannes M.
Object Type: Article
System: The UNT Digital Library
The Cornell-SLAC Pixel Array Detector at LCLS (open access)

The Cornell-SLAC Pixel Array Detector at LCLS

None
Date: November 19, 2012
Creator: Hart, P.; Boutet, S.; Carini, G.; Dragone, A.; Duda, B.; Freytag, D. et al.
Object Type: Article
System: The UNT Digital Library
Scotts Valley Band of Pomo Indians First Steps Toward Tribal Weatherization - Human Capacity Development (open access)

Scotts Valley Band of Pomo Indians First Steps Toward Tribal Weatherization - Human Capacity Development

The objectives of this project are to create jobs and to provide tribal homes and buildings with weatherization assistance for energy efficiency. The project will establish a Tribal Multi-County Weatherization Energy Program to provide training, outreach and education on energy assistance and conservation to low-income families. The Tribes' mission, under its Strategic Energy Plan of 2008, is to promote tribal efficiency, reduce energy costs, create jobs, economic opportunities, and incorporate energy planning in construction and economic development.
Date: June 19, 2012
Creator: Ray, Irenia Quitiquit Gabriel
Object Type: Report
System: The UNT Digital Library
Generic Natural Systems Evaluation - Thermodynamic Database Development and Data Management (open access)

Generic Natural Systems Evaluation - Thermodynamic Database Development and Data Management

Thermodynamic data are essential for understanding and evaluating geochemical processes, as by speciation-solubility calculations, reaction-path modeling, or reactive transport simulation. These data are required to evaluate both equilibrium states and the kinetic approach to such states (via the affinity term or its equivalent in commonly used rate laws). These types of calculations and the data needed to carry them out are a central feature of geochemistry in many applications, including water-rock interactions in natural systems at low and high temperatures. Such calculations are also made in engineering studies, for example studies of interactions involving man-made materials such as metal alloys and concrete. They are used in a fairly broad spectrum of repository studies where interactions take place among water, rock, and man-made materials (e.g., usage on YMP and WIPP). Waste form degradation, engineered barrier system performance, and near-field and far-field transport typically incorporate some level of thermodynamic modeling, requiring the relevant supporting data. Typical applications of thermodynamic modeling involve calculations of aqueous speciation (which is of great importance in the case of most radionuclides), solubilities of minerals and related solids, solubilities of gases, and stability relations among the various possible phases that might be present in a chemical system at …
Date: September 19, 2011
Creator: Wolery, T W & Sutton, M
Object Type: Report
System: The UNT Digital Library