Access
Partner
UNT Libraries Government Documents Department
282
Oklahoma Historical Society
52
UNT Libraries
45
UNT Libraries Special Collections
42
National Museum of the Pacific War/Admiral Nimitz Foundation
16
Sterling Municipal Library
12
UNT Music Library
9
Archer Public Library
6
Comanche Public Library
6
San Antonio Public Library
6
45 More
Collection
Texas Digital Newspaper Program
162
Congressional Research Service Reports
132
Office of Scientific & Technical Information Technical Reports
117
Oklahoma Digital Newspaper Program
59
Tocker Foundation Grant
57
The Greensheet
36
Government Accountability Office Reports
30
Texas Daily Newspaper Association
30
National Museum of the Pacific War Oral History Collection
16
National Museum of the Pacific War Digital Archive
16
76 More
Degree Department
Degree Discipline
Degree Level
States
Year
Month
Day
Language
579 Matching Results
Results open in a new window/tab.
Force Structure: Restructuring and Rebuilding the Army Will Cost Billions of Dollars for Equipment but the Total Cost Is Uncertain
Testimony issued by the Government Accountability Office with an abstract that begins "The high pace of overseas operations is taking a heavy toll on Army equipment. Harsh combat and environmental conditions over sustained periods of time have exacerbated equipment repair, replacement, and recapitalization problems. The Army has also taken steps to restructure its forces before implementing its longer term transformation to the Future Combat System. To support ongoing operations and prepare for the future, the Army has embarked on four key initiatives: (1) restructuring from a division-based force to a modular brigade-based force, (2) expanding the Army by adding about 74,000 people and creating new units, (3) repairing, replacing, and recapitalizing new equipment through its reset program, and (4) replacing equipment borrowed from its pre-positioned equipment sets around the world. Since 2004, Congress has provided billions of dollars to support the Army's equipping needs. GAO has issued many reports on the Army's efforts to equip modular units, expand the Army, reset equipment, and manage and replace prepositioned equipment. This statement, which draws largely on these reports, will address (1) the equipment-related cost of these initiatives, and (2) the management challenges facing the Army and the actions needed to improve its …
Date:
April 10, 2008
Creator:
United States. Government Accountability Office.
Object Type:
Text
System:
The UNT Digital Library
Defense Acquisitions: 2009 Review of Future Combat System Is Critical to Program's Direction
Testimony issued by the Government Accountability Office with an abstract that begins "The Future Combat System (FCS) program--which comprises 14 integrated weapon systems and an advanced information network--is the centerpiece of the Army's effort to transition to a lighter, more agile, and more capable combat force. The substantial technical challenges, the Army's acquisition strategy, and the cost of the program are among the reasons why the program is recognized as needing special oversight and review. This testimony is based on GAO's two March 2008 reports on FCS and addresses (1) how the definition, development, and demonstration of FCS capabilities are proceeding, particularly in light of the go/no-go decision scheduled for 2009; (2) the Army's plans for making production commitments for FCS and any risks related to the completion of development; and (3) the estimated costs for developing and producing FCS."
Date:
April 10, 2008
Creator:
United States. Government Accountability Office.
Object Type:
Text
System:
The UNT Digital Library
Food Safety: Selected Countries' Systems Can Offer Insights into Ensuring Import Safety and Responding to Foodborne Illness
A letter report issued by the Government Accountability Office with an abstract that begins "Like other nations, the United States faces growing food safety challenges resulting from at least three major trends. First, imported food makes up a growing share of the food supply. Second, consumers are increasingly eating foods that are raw or have had minimal processing and that are often associated with foodborne illness. Third, changing demographic patterns mean that more of the U.S. population is, and increasingly will be, susceptible to foodborne illness. In 2005, GAO reported on the approaches and challenges seven countries faced in reorganizing and consolidating food safety functions. Since then, the European Union (EU) has taken on a larger role in overseeing food safety within its 27 member states. GAO was asked to describe how Canada, the EU, Germany, Ireland, Japan, the Netherlands, and the United Kingdom (UK) (1) ensure the safety of imported food, (2) respond to outbreaks of foodborne illness, and (3) measure the effectiveness of their reorganized food safety systems. GAO also asked experts in these countries and the EU to identify emerging food safety challenges that they expect to face over the next decade. In doing this work, GAO …
Date:
June 10, 2008
Creator:
United States. Government Accountability Office.
Object Type:
Report
System:
The UNT Digital Library
Operation Iraqi Freedom: Actions Needed to Enhance DOD Planning for Reposturing of U.S. Forces from Iraq
A letter report issued by the Government Accountability Office with an abstract that begins "The redeployment of U.S. forces from Iraq, a process the Department of Defense (DOD) refers to as "reposturing," will be a massive and expensive effort. As of March 2008, for example, there were about 173,000 pieces of equipment in Iraq, worth about $16.5 billion, that will need to be returned to the United States. The redeployment process following Operation Desert Storm in 1991, a much shorter war, lasted at least 14 months. DOD guidance emphasizes the importance of early planning for this redeployment process. GAO performed this work under the Comptroller General's Authority. GAO examined the (1) status of logistical planning for reposturing U.S. forces from Iraq and associated assumptions and (2) extent to which DOD established roles and responsibilities for managing and executing retrograde from Iraq. GAO also identified issues that DOD will need to consider in its reposture planning. GAO reviewed documents and interviewed officials from over 20 DOD organizations in the United States and Kuwait."
Date:
September 10, 2008
Creator:
United States. Government Accountability Office.
Object Type:
Report
System:
The UNT Digital Library
NASA Workforce: Briefing on National Aeronautics and Space Administration's Use of Term Appointments
Correspondence issued by the Government Accountability Office with an abstract that begins "Congress expanded the National Aeronautics and Space Administration's (NASA) ability to use term appointments to fill civil service positions in 2004. NASA sought this flexibility to ensure that it could hire and retain the workforce it desired. In a joint explanatory statement accompanying the Consolidated Appropriations Act, 2008 (Pub. L. No. 110-161), Congress asked us to review NASA's use of term appointments for civil servant positions. We briefed the committees on the results of our review. This report summarizes that briefing. As agreed to by the committees, this concludes our work performed under this mandate."
Date:
September 10, 2008
Creator:
United States. Government Accountability Office.
Object Type:
Text
System:
The UNT Digital Library
Abortion Services and Military Medical Facilities
In 1993, President Clinton modified the military policy on providing abortions at military medical facilities. Under the change directed by the President, military medical facilities were allowed to perform abortions if paid for entirely with non-Department of Defense (DOD) funds (i.e., privately funded). Over the last three decades, the availability of abortion services at military medical facilities has been subjected to numerous changes and interpretations.
Date:
July 10, 2008
Creator:
Burelli, David F.
Object Type:
Report
System:
The UNT Digital Library
Abortion Services and Military Medical Facilities
The purpose of this report is to describe and discuss the provisions for providing abortion services to military personnel, their dependents, and other military health care beneficiaries at military medical facilities. The report describes the history of these provisions, with particular emphasis on legislative actions. Finally, this report discusses a number of proposals to modify the law, as well as other related legislative and administrative actions.
Date:
July 10, 2008
Creator:
Burrelli, David F.
Object Type:
Report
System:
The UNT Digital Library
Child Pornography: Constitutional Principles and Federal Statutes
This report discusses the constitutional status of child pornography and summarizes federal statutes banning and regulating child pornography as well as selected court cases that have ruled on their constitutionality or interpreted them.
Date:
October 10, 2008
Creator:
Cohen, Henry
Object Type:
Report
System:
The UNT Digital Library
BDDC for nonsymmetric positive definite and symmetric indefinite problems
The balancing domain decomposition methods by constraints are extended to solving both nonsymmetric, positive definite and symmetric, indefinite linear systems. In both cases, certain nonstandard primal constraints are included in the coarse problems of BDDC algorithms to accelerate the convergence. Under the assumption that the subdomain size is small enough, a convergence rate estimate for the GMRES iteration is established that the rate is independent of the number of subdomains and depends only slightly on the subdomain problem size. Numerical experiments for several two-dimensional examples illustrate the fast convergence of the proposed algorithms.
Date:
December 10, 2008
Creator:
Tu, Xuemin & Li, Jing
Object Type:
Article
System:
The UNT Digital Library
Summary of Workshop: Barriers to Energy Efficient Residential Ventilation
The objectives for this workshop were to bring together those with different viewpoints on the implementation of energy efficient ventilation in homes to share their perspectives. The primary benefit of the workshop is to allow the participants to get a broader understanding of the issues involved and thereby make themselves more able to achieve their own goals in this area. In order to achieve this objective each participant was asked to address four objectives from their point of view: (1) Drivers for energy efficient residential ventilation: Why is this an important issue? Who cares about it? Where is the demand: occupants, utilities, regulation, programs, etc? What does sustainability mean in this context? (2) Markets & Technologies: What products, services and systems are out there? What kinds of things are in the pipeline? What is being installed now? Are there regional or other trends? What are the technology interactions with other equipment and the envelope? (3) Barriers to Implementation: What is stopping decision makers from implementing energy-efficient residential ventilation systems? What kind of barriers are there: technological, cost, informational, structural, etc. What is the critical path? (4) Solutions: What can be done to overcome the barriers and how can/should we do …
Date:
January 10, 2008
Creator:
Sherman, Max & Sherman, Max
Object Type:
Report
System:
The UNT Digital Library
Mg-induced increase of bandgap in Zn1-xMgxO nanorods revealed by x-ray absorption and emission spectroscopy
X-ray absorption near-edge structure (XANES) and x-ray emission spectroscopy (XES) measurements were used to investigate the effect of Mg doping in ZnO nanorods. The intensities of the features in the O K-edge XANES spectra of Zn{sub 1-x}Mg{sub x}O nanorods are lower than those of pure ZnO nanorods, suggesting that Mg doping increases the negative effective charge of O ions. XES and XANES spectra of O 2p states indicate that Mg doping raises (lowers) the conduction-band-minimum (valence-band-maximum) and increases the bandgap. The bandgap is found to increase linearly with the Mg content, as revealed by photoluminescence and combined XANES and XES measurements.
Date:
July 10, 2008
Creator:
Pong, Way-Faung; Chiou, J. W.; Tsai, H. M.; Pao, C. W.; Chien, F. Z.; Pong, W. F. et al.
Object Type:
Article
System:
The UNT Digital Library
Calculation Of Change-Changing Cross Sections Of IONS Or Atoms Colliding With Fast IONS Using The Classical Trajectory Method
Evaluation of ion-atom charge-changing cross sections is needed for many accelerator applications. A classical trajectory Monte Carlo (CTMC) simulation has been used to calculate ionization and charge exchange cross sections. For benchmarking purposes, an extensive study has been performed for the simple case of hydrogen and helium targets in collisions with various ions. Despite the fact that the simulation only accounts for classical mechanics, the calculations are comparable to experimental results for projectile velocities in the region corresponding to the vicinity of the maximum cross section. Shortcomings of the CTMC method for multielectron target atoms are discussed.
Date:
October 10, 2008
Creator:
Kaganovich, I. D., Shnidman, Ariel, Mebane, Harrison, Davidson, R.C.
Object Type:
Article
System:
The UNT Digital Library
The Absence of Plasma in"Spark Plasma Sintering"
Spark plasma sintering (SPS) is a remarkable method for synthesizing and consolidating a large variety of both novel and traditional materials. The process typically uses moderate uni-axial pressures (<100 MPa) in conjunction with a pulsing on-off DC current during operation. There are a number of mechanisms proposed to account for the enhanced sintering abilities of the SPS process. Of these mechanisms, the one most commonly put forth and the one that draws the most controversy involves the presence of momentary plasma generated between particles. This study employees three separate experimental methods in an attempt to determine the presence or absence of plasma during SPS. The methods employed include: in-situ atomic emission spectroscopy, direct visual observation and ultra-fast in-situ voltage measurements. It was found using these experimental techniques that no plasma is present during the SPS process. This result was confirmed using several different powders across a wide spectrum of SPS conditions.
Date:
April 10, 2008
Creator:
Hulbert, Dustin M.; Anders, Andre; Dudina, Dina V.; Andersson, Joakim; Jiang, Dongtao; Unuvar, Cosan et al.
Object Type:
Article
System:
The UNT Digital Library
Practical error estimates for Reynolds' lubrication approximation and its higher order corrections
Reynolds lubrication approximation is used extensively to study flows between moving machine parts, in narrow channels, and in thin films. The solution of Reynolds equation may be thought of as the zeroth order term in an expansion of the solution of the Stokes equations in powers of the aspect ratio {var_epsilon} of the domain. In this paper, we show how to compute the terms in this expansion to arbitrary order on a two-dimensional, x-periodic domain and derive rigorous, a-priori error bounds for the difference between the exact solution and the truncated expansion solution. Unlike previous studies of this sort, the constants in our error bounds are either independent of the function h(x) describing the geometry, or depend on h and its derivatives in an explicit, intuitive way. Specifically, if the expansion is truncated at order 2k, the error is O({var_epsilon}{sup 2k+2}) and h enters into the error bound only through its first and third inverse moments {integral}{sub 0}{sup 1} h(x){sup -m} dx, m = 1,3 and via the max norms {parallel} 1/{ell}! h{sup {ell}-1}{partial_derivative}{sub x}{sup {ell}}h{parallel}{sub {infinity}}, 1 {le} {ell} {le} 2k + 2. We validate our estimates by comparing with finite element solutions and present numerical evidence that suggests …
Date:
December 10, 2008
Creator:
Wilkening, Jon
Object Type:
Article
System:
The UNT Digital Library
Models of Longitudinal Space-Charge Impedance for the Study of theMicrobunching Instability
A 1D model of space-charge impedance, assuming atransversely uniform beam with circular cross-section, has been proposedand is being extensively used in the modelling of the microbunchinginstability of relevance for the beam delivery systems of x-ray FELs. Inthis paper we investigate the limitation of the model when applied tostudying the effect of shot noise--one of the sources of themicrobunching instability. We make comparison witha fully 3D calculationand identify the upper end of the frequency spectrum for applicability ofthe 1D model. Relaxation of the assumptions regarding axis-symmetry anduniformity of the transverse density is also reviewed.
Date:
March 10, 2008
Creator:
Venturini, Marco
Object Type:
Article
System:
The UNT Digital Library
Origin and Propagation of Cosmic Rays (Some Highlights)
None
Date:
April 10, 2008
Creator:
Moskalenko, Igor V. & /Stanford U., HEPL /KIPAC, Menlo Park
Object Type:
Article
System:
The UNT Digital Library
Long-term Variations of CO2 Trapped in Different Mechanisms in Deep Saline Formations: A Case Study of the Songliao Basin, China
The geological storage of CO{sub 2} in deep saline formations is increasing seen as a viable strategy to reduce the release of greenhouse gases to the atmosphere. There are numerous sedimentary basins in China, in which a number of suitable CO{sub 2} geologic reservoirs are potentially available. To identify the multi-phase processes, geochemical changes and mineral alteration, and CO{sub 2} trapping mechanisms after CO{sub 2} injection, reactive geochemical transport simulations using a simple 2D model were performed. Mineralogical composition and water chemistry from a deep saline formation of Songliao Basin were used. Results indicate that different storage forms of CO{sub 2} vary with time. In the CO{sub 2} injection period, a large amount of CO{sub 2} remains as a free supercritical phase (gas trapping), and the amount dissolved in the formation water (solubility trapping) gradually increases. Later, gas trapping decreases, solubility trapping increases significantly due to migration and diffusion of the CO{sub 2} plume, and the amount trapped by carbonate minerals increases gradually with time. The residual CO{sub 2} gas keeps dissolving into groundwater and precipitating carbonate minerals. For the Songliao Basin sandstone, variations in the reaction rate and abundance of chlorite, and plagioclase composition affect significantly the estimates of …
Date:
June 10, 2008
Creator:
Zhang, Wei; Li, Yilian; Xu, Tianfu; Cheng, Huilin; Zheng, Yan & Xiong, Peng
Object Type:
Article
System:
The UNT Digital Library
Measurement of the Branching Fraction, Polarization, and CP Asymmetries in B0->rho0rho0 Decay, and Implications for the CKM Angle alpha
We study B{sup 0} {yields} {rho}{sup 0}{rho}{sup 0} decays in a sample of 465 x 10{sup 6} {Upsilon}(4S) {yields} B{bar B} events collected with the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider located at the Stanford Linear Accelerator Center (SLAC). We measure the branching fraction {Beta} = (0.92 {+-} 0.32 {+-} 0.14) x 10{sup -6} and longitudinal polarization fraction f{sub L} = 0.75{sub -0.14}{sup +0.11} {+-} 0.04, where the first uncertainty is statistical and the second is systematic. The evidence for the B{sup 0} {yields} {rho}{sup 0}{rho}{sup 0} signal has a significance of 3.1 standard deviations, including systematic uncertainties. We investigate the proper-time dependence of the longitudinal component in the decay and measure the CP-violating coefficients S{sub L}{sup 00} = (0.3 {+-} 0.7 {+-} 0.2) and C{sub L}{sup 00} = (0.2 {+-} 0.8 {+-} 0.3). They study the implication of these results for the unitarity triangle angle {alpha}.
Date:
September 10, 2008
Creator:
Aubert, B.
Object Type:
Article
System:
The UNT Digital Library
Spin-orbit holds the heavyweight title for Pu and Am: Exchange regains it for Cm
The conclusions of this paper are: (1) The 5f electrons in Cm are near an LS coupling scheme. (2) This coupling scheme allows for a large spin polarization of the 5f electrons, which in turn stabilizes the Cm III crystal structure. (3) Results for Cm show us the recipe for magnetic stabilization of the crystal structure of metals: (A) The metal must be near the itinerant-localized transition where multiple crystal structures have close energies; (B) The metal is just on the magnetic side of the transition; and (C) There must be a magnetic moment large enough to overcome the energy difference between crystal structures, thus dictating the atomic geometry. (4) These results solidify our understanding of magnetically-stabilized metals, showing us where to look for engineered materials with magnetic applications.
Date:
January 10, 2008
Creator:
Moore, K; der Laan, G v & Soderlind, P
Object Type:
Article
System:
The UNT Digital Library
QCD Evolution of the Transverse Momentum Dependent Correlations
We study the QCD evolution for the twist-three quark-gluon correlation functions associated with the transverse momentum odd quark distributions. Different from that for the leading twist quark distributions, these evolution equations involve more general twist-three functions beyond the correlation functions themselves. They provide important information on nucleon structure, and can be studied in the semi-inclusive hadron production in deep inelastic scattering and Drell-Yan lepton pair production in pp scattering process.
Date:
December 10, 2008
Creator:
Zhou, Jian; Liang, Zuo-Tang & Yuan, Feng
Object Type:
Article
System:
The UNT Digital Library
VERTIGO (VERtical Transport In the Global Ocean): A study of particle sources and flux attenuation in the North Pacific
The VERtical Transport In the Global Ocean (VERTIGO) study examined particle sources and fluxes through the ocean's 'twilight zone' (defined here as depths below the euphotic zone to 1000 m). Interdisciplinary process studies were conducted at contrasting sites off Hawaii (ALOHA) and in the NW Pacific (K2) during 3 week occupations in 2004 and 2005, respectively. We examine in this overview paper the contrasting physical, chemical and biological settings and how these conditions impact the source characteristics of the sinking material and the transport efficiency through the twilight zone. A major finding in VERTIGO is the considerably lower transfer efficiency (T{sub eff}) of particulate organic carbon (POC), POC flux 500/150 m, at ALOHA (20%) vs. K2 (50%). This efficiency is higher in the diatom-dominated setting at K2 where silica-rich particles dominate the flux at the end of a diatom bloom, and where zooplankton and their pellets are larger. At K2, the drawdown of macronutrients is used to assess export and suggests that shallow remineralization above our 150 m trap is significant, especially for N relative to Si. We explore here also surface export ratios (POC flux/primary production) and possible reasons why this ratio is higher at K2, especially during the …
Date:
June 10, 2008
Creator:
Buesseler, K. O.; Trull, T. W.; Steinberg, D. K.; Silver, M. W.; Siegel, D. A.; Saitoh, S. I. et al.
Object Type:
Article
System:
The UNT Digital Library
A Theoretical Study of the Two-Dimensional Point Focusing by Two Multilayer Laue Lenses.
Hard x-ray point focusing by two crossed multilayer Laue lenses is studied using a full-wave modeling approach. This study shows that for a small numerical aperture, the two consecutive diffraction processes can be decoupled into two independent ones in respective directions. Using this theoretical tool, we investigated adverse effects of various misalignments on the 2D focus profile and discussed the tolerance to them. We also derived simple expressions that described the required alignment accuracy.
Date:
August 10, 2008
Creator:
Yan,H.; Maser, J.; Kang, H.C.; Macrader, A. & Stephenson, B.
Object Type:
Article
System:
The UNT Digital Library
14-MeV Neutron Generator Used as a Thermal Neutron Source
One of the most important applications of the general purpose Monte Carlo N-Particle (MCNPS and MCNPX) codes is neutron shielding design. We employed this method to simulate the shield of a 14-MeV neutron generator used as a thermal neutron source providing an external thermal neutron beam for testing large area neutron detectors developed for diffraction studies in biology and also useful for national security applications. Nuclear reactors have been the main sources of neutrons used for scientific applications. In the past decade, however, a large number of reactors have been shut down, and the importance of other, smaller devices capable of providing neutrons for research has increased. At Brookhaven National Laboratory a moderated Am-Be neutron source with shielding is used for neutron detector testing. This source is relatively weak, but provides a constant flux of neutrons, even when not in use. The use of a 14 MeV energized neutron generator, with an order of magnitude higher neutron flux has been considered to replace the Am-Be source, but the higher fast neutron yield requires a more careful design of moderator and shielding. In the present paper we describe a proposed shielding configuration based on Monte Carlo calculations, and provide calculated neutron …
Date:
August 10, 2008
Creator:
Dioszegi, I.
Object Type:
Article
System:
The UNT Digital Library
Tracking Non-rigid Structures in Computer Simulations
A key challenge in tracking moving objects is the correspondence problem, that is, the correct propagation of object labels from one time step to another. This is especially true when the objects are non-rigid structures, changing shape, and merging and splitting over time. In this work, we describe a general approach to tracking thousands of non-rigid structures in an image sequence. We show how we can minimize memory requirements and generate accurate results while working with only two frames of the sequence at a time. We demonstrate our results using data from computer simulations of a fluimix problem.
Date:
January 10, 2008
Creator:
Gezahegne, A & Kamath, C
Object Type:
Article
System:
The UNT Digital Library