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ADDING REALISM TO NUCLEAR MATERIAL DISSOLVING ANALYSIS (open access)

ADDING REALISM TO NUCLEAR MATERIAL DISSOLVING ANALYSIS

Two new criticality modeling approaches have greatly increased the efficiency of dissolver operations in H-Canyon. The first new approach takes credit for the linear, physical distribution of the mass throughout the entire length of the fuel assembly. This distribution of mass is referred to as the linear density. Crediting the linear density of the fuel bundles results in using lower fissile concentrations, which allows higher masses to be charged to the dissolver. Also, this approach takes credit for the fact that only part of the fissile mass is wetted at a time. There are multiple assemblies stacked on top of each other in a bundle. On average, only 50-75% of the mass (the bottom two or three assemblies) is wetted at a time. This means that only 50-75% (depending on operating level) of the mass is moderated and is contributing to the reactivity of the system. The second new approach takes credit for the progression of the dissolving process. Previously, dissolving analysis looked at a snapshot in time where the same fissile material existed both in the wells and in the bulk solution at the same time. The second new approach models multiple consecutive phases that simulate the fissile material …
Date: August 15, 2011
Creator: Williamson, B.
Object Type: Article
System: The UNT Digital Library
Anomalous transient uplift observed at the Lop Nor, China nuclear test site using satellite radar interferometry time-series analysis (open access)

Anomalous transient uplift observed at the Lop Nor, China nuclear test site using satellite radar interferometry time-series analysis

None
Date: August 15, 2011
Creator: Vincent, P; Buckley, S M; Yang, D & Carle, S F
Object Type: Article
System: The UNT Digital Library
Building Toxic Metal Characterization and Decontamination Report: Area 6, Building 914 (open access)

Building Toxic Metal Characterization and Decontamination Report: Area 6, Building 914

The purpose of this report is to outline the toxic metal characterization and decontamination efforts in Area 6, Building 914. This includes the initial building inspection, the hotspot sampling, results/findings, building cleanup, and the verification sampling. Building 914 is a steel light frame building that was constructed in 1992. It is about 16,454 square feet, and five employees are assigned to this building. According to the building's floor plan blueprints, it could be inferred that this building was once a Wiremen/Lineman shop. In 2002-2004, the National Nuclear Security Administration Nevada Site Office embarked on a broad characterization of beryllium (Be) surface concentrations throughout the North Las Vegas Facility, the Nevada National Security Site (NNSS), and ancillary facilities like the Special Technologies Laboratory, Remote Sensing Laboratory, etc. Building 914 was part of this characterization. The results of the 2002 study illustrated that the metal housekeeping limits were within acceptable limits and from a Be standpoint, the building was determined to be fit for occupancy. On March 2, 2011, based on a request from Building 914 users, National Security Technologies, LLC (NSTec) Industrial Hygiene (IH) collected bulk samples from the southwest corner of Building 914 at heights above 6 feet where black …
Date: August 15, 2011
Creator: Hygiene, NSTec Industrial
Object Type: Report
System: The UNT Digital Library
Built-in and Induced Polarization Across LaAlO3/SrTiO3 Heterojunctions (open access)

Built-in and Induced Polarization Across LaAlO3/SrTiO3 Heterojunctions

Ionic crystals terminated at oppositely charged polar surfaces are inherently unstable and expected to undergo surface reconstructions to maintain electrostatic stability. Essentially, an electric field that arises between oppositely charged atomic planes gives rise to a built-in potential that diverges with thickness. Here we present evidence of such a built-in potential across polar LaAlO{sub 3} thin films grown on SrTiO{sub 3} substrates, a system well known for the electron gas that forms at the interface. By performing tunneling measurements between the electron gas and metallic electrodes on LaAlO{sub 3} we measure a built-in electric field across LaAlO{sub 3} of 80.1 meV/{angstrom}. Additionally, capacitance measurements reveal the presence of an induced dipole moment across the heterostructure. We forsee use of the ionic built-in potential as an additional tuning parameter in both existing and novel device architectures, especially as atomic control of oxide interfaces gains widespread momentum.
Date: August 15, 2011
Creator: Guneeta, Singh-Bhalla
Object Type: Article
System: The UNT Digital Library
Campbell penetration depth in Fe-based superconductors (open access)

Campbell penetration depth in Fe-based superconductors

A 'true' critical current density, j{sub c}, as opposite to commonly measured relaxed persistent (Bean) current, j{sub B}, was extracted from the Campbell penetration depth, {lambda}{sub c}(T,H) measured in single crystals of LiFeAs, and optimally electron-doped Ba(Fe{sub 0.954}Ni{sub 0.046}){sub 2}As{sub 2} (FeNi122). In LiFeAs, the effective pinning potential is nonparabolic, which follows from the magnetic field - dependent Labusch parameter {alpha}. At the equilibrium (upon field - cooling), {alpha}(H) is non-monotonic, but it is monotonic at a finite gradient of the vortex density. This behavior leads to a faster magnetic relaxation at the lower fields and provides a natural dynamic explanation for the fishtail (second peak) effect. We also find the evidence for strong pinning at the lower fields.The inferred field dependence of the pinning potential is consistent with the evolution from strong pinning, through collective pinning, and eventually to a disordered vortex lattice. The value of j{sub c}(2 K) {approx_equal} 1.22 x 10{sup 6} A/cm{sup 2} provide an upper estimate of the current carrying capability of LiFeAs. Overall, vortex behavior of almost isotropic, fully-gapped LiFeAs is very similar to highly anisotropic d-wave cuprate superconductors, the similarity that requires further studies in order to understand unconventional superconductivity in cuprates and …
Date: August 15, 2011
Creator: Prommapan, Plegchart
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Comparison of Waste Feed Delivery Small Scale Mixing Demonstration Simulant to Hanford Waste (open access)

Comparison of Waste Feed Delivery Small Scale Mixing Demonstration Simulant to Hanford Waste

'The Hanford double-shell tank (DST) system provides the staging location for waste feed delivery to the Hanford Tank Waste Treatment and Immobilization Plant (WTP). Hall (2008) includes WTP acceptance criteria that describe physical and chemical characteristics of the waste that must be certified as acceptable before the waste is transferred from the DSTs to the WTP. One of the more challenging requirements relates to the sampling and characterization of the undissolved solids (UDS) in a waste feed DST. The objectives of Washington River Protection Solutions' (WRPS) Small Scale Mixing Demonstration (SSMD) project are to understand and demonstrate the DST sampling and batch transfer performance at multiple scales using slurry simulants comprised of UDS particles and liquid (Townson 2009). The SSMD project utilizes geometrically scaled DST feed tanks to generate mixing, sampling, and transfer test data. In Phase 2 of the testing, RPP-49740, the 5-part simulant defined in RPP-48358 was used as the waste slurry simulant. The Phase 2 test data are being used to estimate the expected performance of the prototypic systems in the full-scale DSTs. As such, understanding of the how the small-scale systems as well as the simulant relate to the full-scale DSTs and actual waste is required. …
Date: August 15, 2011
Creator: Wells, Beric E.; Gauglitz, Phillip A. & Rector, David R.
Object Type: Report
System: The UNT Digital Library
Desalination: Technologies, Use, and Congressional Issues (open access)

Desalination: Technologies, Use, and Congressional Issues

This report discusses Desalination processes that generally treat seawater or brackish water to produce a stream of freshwater, and a separate, saltier stream of water that has to be disposed.
Date: August 15, 2011
Creator: Carter, Nicole T.
Object Type: Report
System: The UNT Digital Library
Dissecting the Wjj Anomaly: Diagnostic Tests of a Leptophobic Z' (open access)

Dissecting the Wjj Anomaly: Diagnostic Tests of a Leptophobic Z'

We examine the scenario where a leptophobic Z{prime} boson accounts for the excess of events in the Wjj channel as observed by CDF. We assume generation independent couplings for the Z{prime} and obtain allowed regions for the four hadronic couplings using the measured cross section as well as constraints from dijet production at UA2. These coupling regions translate into well-determined rates for the associated production of Z/{gamma} + Z{prime} at the Tevatron and LHC, as well as W + Z{prime} at the LHC,that are directly correlated with the Wjj rate observed at the Tevatron. The Wjj rate at the LHC is large and this channel should be observed soon once the SM backgrounds are under control. The rates for Z/{gamma} + Z{prime} associated production are smaller, and these processes should not yet have been observed at the Tevatron given the expected SM backgrounds. In addition, we show that more coupling information is obtainable from the M{sub WZ{prime}} distribution. Once detected, these processes will provide further valuable information on the Z{prime} boson couplings.
Date: August 15, 2011
Creator: Hewett, J. L. & Rizzo, T. G.
Object Type: Article
System: The UNT Digital Library
Doping Dependence of the $(\pi,\pi)$ Shadow Band in La-Based Cuprates Studied by Angle-Resolved Photoemission Spectroscopy (open access)

Doping Dependence of the $(\pi,\pi)$ Shadow Band in La-Based Cuprates Studied by Angle-Resolved Photoemission Spectroscopy

The ({pi},{pi}) shadow band (SB) in La-based cuprate family (La214) was studied by angle-resolved photoemission spectroscopy (ARPES) over a wide doping range from x = 0.01 to x = 0.25. Unlike the well-studied case of the Bi-based cuprate family, an overall strong, monotonic doping dependence of the SB intensity at the Fermi level (E{sub F}) was observed. In contrast to a previous report for the presence of the SB only close to x = 1/8, we found it exists in a wide doping range, associated with a doping-independent ({pi},{pi}) wave vector but strongly doping-dependent intensity: It is the strongest at x {approx} 0.03 and systematically diminishes as the doping increases until it becomes negligible in the overdoped regime. This SB with the observed doping dependence of intensity can in principle be caused by the antiferromagnetic fluctuations or a particular form of low-temperature orthorhombic lattice distortion known to persist up to x {approx} 0.21 in the system, with both being weakened with increasing doping. However, a detailed binding energy dependent analysis of the SB at x = 0.07 does not appear to support the former interpretation, leaving the latter as a more plausible candidate, despite a challenge in quantitatively linking the …
Date: August 15, 2011
Creator: Shen, Z. X.
Object Type: Article
System: The UNT Digital Library
Electric Field Penetration in Au/Nb:SrTiO3 Schottky Junctions Probed by Bias-Dependent Internal Photoemission (open access)

Electric Field Penetration in Au/Nb:SrTiO3 Schottky Junctions Probed by Bias-Dependent Internal Photoemission

Electric field penetration into the metallic side of a Schottky junction is in principle a universal phenomenon, the magnitude of which increases with the semiconductor permittivity. Here, we quantitatively probe this effect using bias-dependent internal photoemission spectroscopy at the Schottky junction between a large dielectric permittivity semiconductor SrTiO{sub 3} and gold. A clear linear reduction of the barrier height with increasing interface electric field was observed, highlighting the importance of field penetration into the gold. The interfacial permittivity of SrTiO{sub 3} at the interface is reduced from the bulk value, reflecting intrinsic suppression at the interface.
Date: August 15, 2011
Creator: Hikita, Y.
Object Type: Article
System: The UNT Digital Library
The European Union: Foreign and Security Policy (open access)

The European Union: Foreign and Security Policy

This report provides an overview on the foreign and security policy on the European Union.
Date: August 15, 2011
Creator: Mix, Derek E.
Object Type: Report
System: The UNT Digital Library
Evaluation of the Impact of the Defense Waste Processing Facility (DWPF) Laboratory Germanium Oxide Use on Recycle Transfers to the H-Tank Farm (open access)

Evaluation of the Impact of the Defense Waste Processing Facility (DWPF) Laboratory Germanium Oxide Use on Recycle Transfers to the H-Tank Farm

When processing High Level Waste (HLW) glass, the Defense Waste Processing Facility (DWPF) cannot wait until the melt or waste glass has been made to assess its acceptability, since by then no further changes to the glass composition and acceptability are possible. Therefore, the acceptability decision is made on the upstream feed stream, rather than on the downstream melt or glass product. This strategy is known as 'feed forward statistical process control.' The DWPF depends on chemical analysis of the feed streams from the Sludge Receipt and Adjustment Tank (SRAT) and the Slurry Mix Evaporator (SME) where the frit plus adjusted sludge from the SRAT are mixed. The SME is the last vessel in which any chemical adjustments or frit additions can be made. Once the analyses of the SME product are deemed acceptable, the SME product is transferred to the Melter Feed Tank (MFT) and onto the melter. The SRAT and SME analyses have been analyzed by the DWPF laboratory using a 'Cold Chemical' method but this dissolution did not adequately dissolve all the elemental components. A new dissolution method which fuses the SRAT or SME product with cesium nitrate (CsNO{sub 3}), germanium (IV) oxide (GeO{sub 2}) and cesium …
Date: August 15, 2011
Creator: Jantzen, Carol M. & Laurinat, J. E.
Object Type: Report
System: The UNT Digital Library
Examining Uncertainty in Demand Response Baseline Models and Variability in Automated Response to Dynamic Pricing (open access)

Examining Uncertainty in Demand Response Baseline Models and Variability in Automated Response to Dynamic Pricing

Controlling electric loads to deliver power system services presents a number of interesting challenges. For example, changes in electricity consumption of Commercial and Industrial (C&I) facilities are usually estimated using counterfactual baseline models, and model uncertainty makes it difficult to precisely quantify control responsiveness. Moreover, C&I facilities exhibit variability in their response. This paper seeks to understand baseline model error and demand-side variability in responses to open-loop control signals (i.e. dynamic prices). Using a regression-based baseline model, we define several Demand Response (DR) parameters, which characterize changes in electricity use on DR days, and then present a method for computing the error associated with DR parameter estimates. In addition to analyzing the magnitude of DR parameter error, we develop a metric to determine how much observed DR parameter variability is attributable to real event-to-event variability versus simply baseline model error. Using data from 38 C&I facilities that participated in an automated DR program in California, we find that DR parameter errors are large. For most facilities, observed DR parameter variability is likely explained by baseline model error, not real DR parameter variability; however, a number of facilities exhibit real DR parameter variability. In some cases, the aggregate population of C&I …
Date: August 15, 2011
Creator: Mathieu, Johanna L.; Callaway, Duncan S. & Kiliccote, Sila
Object Type: Article
System: The UNT Digital Library
The Express-Star (Chickasha, Okla.), Ed. 1 Monday, August 15, 2011 (open access)

The Express-Star (Chickasha, Okla.), Ed. 1 Monday, August 15, 2011

Daily newspaper from Chickasha, Oklahoma that includes local, state, and national news along with advertising.
Date: August 15, 2011
Creator: DeSilver, Debi
Object Type: Newspaper
System: The Gateway to Oklahoma History
Federal Agency Authority to Contract for Electric Power and Renewable Energy Supply (open access)

Federal Agency Authority to Contract for Electric Power and Renewable Energy Supply

None
Date: August 15, 2011
Creator: Andrews, Anthony
Object Type: Report
System: The UNT Digital Library
Federal Register, Volume 76, Number 157, August 15, 2011, Pages 50403-50660 (open access)

Federal Register, Volume 76, Number 157, August 15, 2011, Pages 50403-50660

Daily publication of the U.S. Office of the Federal Register contains rules and regulations, proposed legislation and rule changes, and other notices, including "Presidential proclamations and Executive Orders, Federal agency documents having general applicability and legal effect, documents required to be published by act of Congress, and other Federal agency documents of public interest" (p. ii). Table of Contents starts on page iii.
Date: August 15, 2011
Creator: United States. Office of the Federal Register.
Object Type: Journal/Magazine/Newsletter
System: The UNT Digital Library
FINAL PROJECT REPORT: A Geophysical Characterization & Monitoring Strategy for Determining Hydrologic Processes in the Hyporheic Corridor at the Hanford 300-Area (open access)

FINAL PROJECT REPORT: A Geophysical Characterization & Monitoring Strategy for Determining Hydrologic Processes in the Hyporheic Corridor at the Hanford 300-Area

The primary objective of this research was to advance the prediction of solute transport between the Uranium contaminated Hanford aquifer and the Columbia River at the Hanford 300 Area by improving understanding of how fluctuations in river stage, combined with subsurface heterogeneity, impart spatiotemporal complexity to solute exchange along the Columbia River corridor. Our work explored the use of continuous waterborne electrical imaging (CWEI), in conjunction with fiber-optic distributed temperature sensor (FO-DTS) and time-lapse resistivity monitoring, to improve the conceptual model for how groundwater/surface water exchange regulates uranium transport. We also investigated how resistivity and induced polarization can be used to generate spatially rich estimates of the variation in depth to the Hanford-Ringold (H-R) contact between the river and the 300 Area Integrated Field Research Challenge (IFRC) site. Inversion of the CWEI datasets (a data rich survey containing ~60,000 measurements) provided predictions of the distributions of electrical resistivity and polarizability, from which the spatial complexity of the primary hydrogeologic units along the river corridor was reconstructed. Variation in the depth to the interface between the overlying coarse-grained, high permeability Hanford Formation and the underlying finer-grained, less permeable Ringold Formation, an important contact that limits vertical migration of contaminants, has been …
Date: August 15, 2011
Creator: Slater, Lee
Object Type: Report
System: The UNT Digital Library

Finish Forty and Home: the Untold World War II Story of B-24s in the Pacific

Access: Use of this item is restricted to the UNT Community
During the early years of World War II in the Pacific theatre, against overwhelming odds, young American airmen flew the longest and most perilous bombing missions of the war. They faced determined Japanese fighters without fighter escort, relentless anti-aircraft fire with no deviations from target, and thousands of miles of over-water flying with no alternative landing sites. Finish Forty and Home is the true story of the men and missions of the 11th Bombardment Group as it fought alone and unheralded in the South Central Pacific, while America had its eyes on the war in Europe. After bombing Nauru, the squadron moves on to bomb Wake Island, Tarawa, and finally Iwo Jima. These missions bring American forces closer and closer to the Japanese home islands and precede the critical American invasions of Tarawa and Iwo Jima. The 42nd Squadron’s losses through 1943 were staggering: 50 out of 110 airmen killed. “Finish Forty and Home is a treasure: poignant, thrilling, and illuminating.”—Laura Hillenbrand, best-selling author of Unbroken and Seabiscuit
Date: August 15, 2011
Creator: Scearce, Phil
Object Type: Book
System: The UNT Digital Library
[Funeral Program for Dorothy Mae Phillips, August 15, 2011] (open access)

[Funeral Program for Dorothy Mae Phillips, August 15, 2011]

Funeral program for Sister Dorothy Mae Phillips, born July 20, 1936 and died August 6, 2011. The funeral was held August 15, 2011 at Bethel African Methodist Episcopal Church, officiated by Rev. Dr. W. Raymond Bryant. Funeral arrangements were made through Lewis Funeral Home and she was buried in Fort Sam Houston National Cemetery in San Antonio, Texas.
Date: August 15, 2011
Creator: unknown
Object Type: Pamphlet
System: The Portal to Texas History
Generalized Attractor Points in Gauged Supergravity (open access)

Generalized Attractor Points in Gauged Supergravity

The attractor mechanism governs the near-horizon geometry of extremal black holes in ungauged 4D N=2 supergravity theories and in Calabi-Yau compactifications of string theory. In this paper, we study a natural generalization of this mechanism to solutions of arbitrary 4D N=2 gauged supergravities. We define generalized attractor points as solutions of an ansatz which reduces the Einstein, gauge field, and scalar equations of motion to algebraic equations. The simplest generalized attractor geometries are characterized by non-vanishing constant anholonomy coefficients in an orthonormal frame. Basic examples include Lifshitz and Schroedinger solutions, as well as AdS and dS vacua. There is a generalized attractor potential whose critical points are the attractor points, and its extremization explains the algebraic nature of the equations governing both supersymmetric and non-supersymmetric attractors.
Date: August 15, 2011
Creator: Kachru, Shamit; /Stanford U., Phys. Dept. /SLAC; Kallosh, Renata; /Stanford U., Phys. Dept.; Shmakova, Marina & /KIPAC, Menlo Park /SLAC /Stanford U., Phys. Dept.
Object Type: Article
System: The UNT Digital Library

[Helen Snapp Wearing Uniform]

Photograph of Helen Snapp gazing off camera. She wears a Santiago Blue uniform and holds the Gold Congressional Medal around her neck.
Date: August 15, 2011
Creator: unknown
Object Type: Photograph
System: The Portal to Texas History
Higgs Properties in the Fourth Generation MSSM: Boosted Signals Over the 3G Plan (open access)

Higgs Properties in the Fourth Generation MSSM: Boosted Signals Over the 3G Plan

The generalization of the MSSM to the case of four chiral fermion generations (4GMSSM) can lead to significant changes in the phenomenology of the otherwise familiar Higgs sector. In most of the 3GMSSM parameter space, the lighter CP-even h is {approx} 115-125 GeV and mostly Standard Model-like while H,A,H{sup {+-}} are all relatively heavy. Furthermore, the ratio of Higgs vevs, tan {beta}, is relatively unconstrained. In contrast to this, in the 4GMSSM, heavy fourth generation fermion loops drive the masses of h,H,H{sup {+-}} to large values while the CP-odd boson, A, can remain relatively light and tan {beta} is restricted to the range 1/2 {approx}< tan {beta} {approx}< 2 due to perturbativity requirements on Yukawa couplings. We explore this scenario in some detail, concentrating on the collider signatures of the light CP-odd Higgs at both the Tevatron and LHC. We find that while gg {yields} A may lead to a potential signal in the {tau}{sup +}{tau}{sup -} channel at the LHC, A may first be observed in the {gamma}{gamma} channel due to a highly loop-enhanced cross section that can be more than an order of magnitude greater than that of a SM Higgs for A masses of {approx} 115-120 and …
Date: August 15, 2011
Creator: Cotta, R. C.; Hewett, J. L.; Ismail, A.; Le, M. -P. & Rizzo, T. G.
Object Type: Article
System: The UNT Digital Library
Improving the phase stability and oxidation resistance of B-NiAl (open access)

Improving the phase stability and oxidation resistance of B-NiAl

High temperature alloys are essential to many industries that require a stable material to perform in harsh oxidative environments. Many of these alloys are suited for specific applications such as jet engine turbine blades where most other materials would either melt or oxidize and crumble (1). These alloys must have a high melting temperature, excellent oxidation resistance, good creep resistance, and decent fracture toughness to be successfully used in such environments. The discovery of Ni based superalloys in the 1940s revolutionized the high temperature alloy industry and there has been continued development of these alloys since their advent (2). These materials are capable of operating in oxidative environments in the presence of combustion gases, water vapor and at temperatures around 1050 C. Demands for increased f uel efficiency, however, has highlighted the need for materials that can be used under similar atmospheres and at temperatures in excess of 1200 C. The current Ni based superalloys are restricted to lower temperatures due to the presence of a number of low melting phases that result in softening of the alloys above 1000 C. Therefore, recent research has been aimed at exploring and developing newer alloy systems that can meet the escalating requirements. …
Date: August 15, 2011
Creator: Brammer, Travis
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Improving the Top Quark Forward-Backward Asymmetry Measurement at the LHC (open access)

Improving the Top Quark Forward-Backward Asymmetry Measurement at the LHC

At the LHC, top quark pairs are dominantly produced from gluons, making it difficult to measure the top quark forward-backward asymmetry. To improve the asymmetry measurement, we study variables that can distinguish between top quarks produced from quarks and those from gluons: the invariant mass of the top pair, the rapidity of the top-antitop system in the lab frame, the rapidity of the top quark in the top-antitop rest frame, the top quark polarization and the top-antitop spin correlation. We combine all the variables in a likelihood discriminant method to separate quark-initiated events from gluon-initiated events. We apply our method on models including G-prime's and W-prime's motivated by the recent observation of a large top quark forward-backward asymmetry at the Tevatron. We have found that the significance of the asymmetry measurement can be improved by 10% to 30%. At the same time, the central values of the asymmetry increase by 40% to 100%. We have also analytically derived the best spin quantization axes for studying top quark polarization as well as spin-correlation for the new physics models.
Date: August 15, 2011
Creator: Bai, Yang & Han, Zhenyu
Object Type: Article
System: The UNT Digital Library