Iterative Self-Dual Reconstruction on Radar Image Recovery (open access)

Iterative Self-Dual Reconstruction on Radar Image Recovery

Imaging systems as ultrasound, sonar, laser and synthetic aperture radar (SAR) are subjected to speckle noise during image acquisition. Before analyzing these images, it is often necessary to remove the speckle noise using filters. We combine properties of two mathematical morphology filters with speckle statistics to propose a signal-dependent noise filter to multiplicative noise. We describe a multiscale scheme that preserves sharp edges while it smooths homogeneous areas, by combining local statistics with two mathematical morphology filters: the alternating sequential and the self-dual reconstruction algorithms. The experimental results show that the proposed approach is less sensitive to varying window sizes when applied to simulated and real SAR images in comparison with standard filters.
Date: May 21, 2010
Creator: Martins, Charles; Medeiros, Fatima; Ushizima, Daniela; Bezerra, Francisco; Marques, Regis & Mascarenhas, Nelson
Object Type: Article
System: The UNT Digital Library
Analytical solution for Joule-Thomson cooling during CO2 geo-sequestration in depleted oil and gas reservoirs (open access)

Analytical solution for Joule-Thomson cooling during CO2 geo-sequestration in depleted oil and gas reservoirs

Mathematical tools are needed to screen out sites where Joule-Thomson cooling is a prohibitive factor for CO{sub 2} geo-sequestration and to design approaches to mitigate the effect. In this paper, a simple analytical solution is developed by invoking steady-state flow and constant thermophysical properties. The analytical solution allows fast evaluation of spatiotemporal temperature fields, resulting from constant-rate CO{sub 2} injection. The applicability of the analytical solution is demonstrated by comparison with non-isothermal simulation results from the reservoir simulator TOUGH2. Analysis confirms that for an injection rate of 3 kg s{sup -1} (0.1 MT yr{sup -1}) into moderately warm (>40 C) and permeable formations (>10{sup -14} m{sup 2} (10 mD)), JTC is unlikely to be a problem for initial reservoir pressures as low as 2 MPa (290 psi).
Date: May 21, 2010
Creator: Mathias, S.A.; Gluyas, J.G.; Oldenburg, C.M. & Tsang, C.-F.
Object Type: Article
System: The UNT Digital Library
Probing Radiation Damage in Plutonium Alloys with Multiple Measurement Techniques (open access)

Probing Radiation Damage in Plutonium Alloys with Multiple Measurement Techniques

A material subjected to radiation damage will usually experience changes in its physical properties. Measuring these changes in the physical properties provides a basis to study radiation damage in a material which is important for a variety of real world applications from reactor materials to semiconducting devices. When investigating radiation damage, the relative sensitivity of any given property can vary considerably based on the concentration and type of damage present as well as external parameters such as the temperature and starting material composition. By measuring multiple physical properties, these differing sensitivities can be leveraged to provide greater insight into the different aspects of radiation damage accumulation, thereby providing a broader understanding of the mechanisms involved. In this report, self-damage from {alpha}-particle decay in Pu is investigated by measuring two different properties: magnetic susceptibility and resistivity. The results suggest that while the first annealing stage obeys second order chemical kinetics, the primary mechanism is not the recombination of vacancy-interstitial close pairs.
Date: April 21, 2010
Creator: McCall, S K; Fluss, M J & Chung, B W
Object Type: Article
System: The UNT Digital Library
Algeria: Current Issues (open access)

Algeria: Current Issues

This report examines the current state of Algeria, including the country's associations with terrorism, despite steady decreases of domestic terrorism; the lessening in power of the Algerian military; and growing oil revenues.
Date: January 21, 2010
Creator: Migdalovitz, Carol
Object Type: Report
System: The UNT Digital Library
Turkey: Politics of Identity and Power (open access)

Turkey: Politics of Identity and Power

Turkey has become increasingly assertive on the international stage. Members of Congress and other U.S. officials require an understanding of the current domestic political situation that, combined with a exceptionally robust economy, has enabled the ruling Justice and Development Party (AKP) to act so confidently in order to develop appropriate policies. As a contribution toward that goal, this report provides an overview of the Turkish domestic political scene. It does not address specific foreign policy issues, which will be the subject of a separate report.
Date: September 21, 2010
Creator: Migdalovitz, Carol
Object Type: Report
System: The UNT Digital Library
Design of a Rayleigh-Taylor experiment to Measure Strength at High Pressures (open access)

Design of a Rayleigh-Taylor experiment to Measure Strength at High Pressures

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Date: May 21, 2010
Creator: Mikaelian, K O
Object Type: Article
System: The UNT Digital Library

Durability of Poly (Methyl Methacrylate) Lenses Used in Concentrating Photovoltaics

This presentation reports the findings of NREL's screen test to characterize the durability of poly (methyl methacrylate) lenses used in concentrated photovoltaics.
Date: October 21, 2010
Creator: Miller, D.; Gedvilas, L.; To, B.; Kennedy, C. & Kurtz, S.
Object Type: Presentation
System: The UNT Digital Library
The Emergency Alert System (EAS) and All-Hazard Warnings (open access)

The Emergency Alert System (EAS) and All-Hazard Warnings

This report discusses the mainstays of the U.S. capacity to issue warnings: the Emergency Alert System (EAS), which relies primarily on broadcasting media, and the National Oceanic and Atmospheric Administration (NOAA) Weather Radio All-Hazards Network.
Date: January 21, 2010
Creator: Moore, Linda K.
Object Type: Report
System: The UNT Digital Library
Spectrum Policy in the Age of Broadband: Issues for Congress (open access)

Spectrum Policy in the Age of Broadband: Issues for Congress

This report discusses spectrum policy issues in the 111th Congress. In formulating spectrum policy, mainstream viewpoints generally diverge on whether to give priority to market economics or social goals. Among the spectrum policy initiatives that have been proposed in Congress in recent years are: allocating more spectrum for unlicensed use; auctioning airwaves currently allocated for federal use; and devising new fees on spectrum use, notably those collected by the FCC's statutory authority to implement these measures is limited.
Date: June 21, 2010
Creator: Moore, Linda K.
Object Type: Report
System: The UNT Digital Library
China-U.S. Trade Issues (open access)

China-U.S. Trade Issues

This report provides an overview of U.S.-China economic relations, surveys major trade disputes, and lists bills introduced in the 111th Congress that could affect bilateral commercial ties.
Date: June 21, 2010
Creator: Morrison, Wayne M.
Object Type: Report
System: The UNT Digital Library
Development of tools and techniques for momentum compression of fast rare isotopes (open access)

Development of tools and techniques for momentum compression of fast rare isotopes

As part of our past research and development work, we have created and developed the LISE++ simulation code [Tar04, Tar08]. The LISE++ package was significantly extended with the addition of a Monte Carlo option that includes an option for calculating ion trajectories using a Taylor-series expansion up to fifth order, and implementation of the MOTER Monte Carlo code [Kow87] for ray tracing of the ions into the suite of LISE++ codes. The MOTER code was rewritten from FORTRAN into C++ and transported to the MS-Windows operating system. Extensive work went into the creation of a user-friendly interface for the code. An example of the graphical user interface created for the MOTER code is shown in the left panel of Figure 1 and the results of a typical calculation for the trajectories of particles that pass through the A1900 fragment separator are shown in the right panel. The MOTER code is presently included as part of the LISE++ package for downloading without restriction by the worldwide community. The LISE++ was extensively developed and generalized to apply to any projectile fragment separator during the early phase of this grant. In addition to the inclusion of the MOTER code, other important additions to …
Date: November 21, 2010
Creator: Morrissey, David J.; Sherrill, Bradley M. & Tarasov, Oleg
Object Type: Report
System: The UNT Digital Library
Analysis of Radioactive Releases During Proposed Demolition Activities for the 224-U and 224-UA Buildings - Addendum (open access)

Analysis of Radioactive Releases During Proposed Demolition Activities for the 224-U and 224-UA Buildings - Addendum

A post-demolition modeling analysis is conducted that compares during-demolition atmospheric concentration monitoring results with modeling results based on the actual meteorological conditions during the demolition activities. The 224-U and 224-UA Buildings that were located in the U-Plant UO3 complex in the 200 West Area of the Hanford Site were demolished during the summer of 2010. These facilities converted uranyl nitrate hexahydrate (UNH), a product of Hanford’s Plutonium-Uranium Extraction (PUREX) Plant, into uranium trioxide (UO3). This report is an addendum to a pre-demolition emission analysis and air dispersion modeling effort that was conducted for proposed demolition activities for these structures.
Date: December 21, 2010
Creator: Napier, Bruce A.; Rishel, Jeremy P.; Droppo, James G.; Joyce, Kevin E. & Strom, Daniel J.
Object Type: Report
System: The UNT Digital Library
Aerosol-Assisted Solid Debris Collection for the National Ignition Facility (open access)

Aerosol-Assisted Solid Debris Collection for the National Ignition Facility

The National Ignition Facility (NIF) has been completed and has made its first shots on-target. While upcoming experiments will be focused on achieving ignition, a variety of subsequent experiments are planned for the facility, including measurement of cross sections, astrophysical measurements, and investigation of hydrodynamic instability in the target capsule. In order to successfully execute several of these planned experiments, the ability to collect solid debris following a NIF capsule shot will be required. The ability to collect and analyze solid debris generated in a shot at the National Ignition Facility (NIF) will greatly expand the number of nuclear reactions studied for diagnostic purposes. Currently, reactions are limited to only those producing noble gases for cryogenic collection and counting with the Radchem Apparatus for Gas Sampling (RAGS). The radchem solid collection diagnostic has already been identified by NIF to be valuable for the determination and understanding of mix generated in the target capsule's ablation. LLNL is currently developing this solid debris collection capability at NIF, and is in the stage of testing credible designs. Some of these designs explore the use of x-ray generated aerosols to assist in collection of solid debris. However, the variety of harsh experimental conditions this …
Date: May 21, 2010
Creator: Nelson, S. L.; Shaughnessy, D. A.; Moody, K. J.; Ivanov, V. V.; Astanovitskiy, A. L.; Lewis, L. A. et al.
Object Type: Article
System: The UNT Digital Library
Radiochemistry as a (rho)R Diagnostic with the RAGS Gas Collection System (open access)

Radiochemistry as a (rho)R Diagnostic with the RAGS Gas Collection System

Radiochemical diagnostic techniques such as gas-phase capsule debris analysis may prove to be successful methods for establishing the success or failure of ignition experiments at the National Ignition Facility (NIF). Samples in the gas phase offer the most direct method of collection by simply pumping out the large target chamber following a NIF shot. The target capsules will be prepared with dopants which will produce radioactive noble gas isotopes upon activation with neutrons. We have designed and constructed the Radchem Apparatus for Gas Sampling (RAGS) in order to collect post-shot gaseous samples for NIF capsule diagnostics. The design of RAGS incorporates multiple stages intended to purify, transfer, and count the radioactive decays from gaseous products synthesized in NIF experiments. At the moment the dopant of choice is {sup 124}Xe, which will undergo (n,{gamma}) and (n, 2n) reactions to produce {sup 125}Xe and {sup 123}Xe. The half-lives of each are on the order of multiple hours and are suitable for long-term gamma-counting. These isotopes and the rest of the gases evolved in a NIF shot will be drawn through the NIF turbo pumps, past the temporarily shuttered cryo pumps (to aid our collection efficiency), and towards the first main portion of …
Date: May 21, 2010
Creator: Nelson, S. L.; Shaughnessy, D. A.; Schneider, D. H.; Stoeffl, W.; Moody, K. J.; Cerjan, C. et al.
Object Type: Article
System: The UNT Digital Library
Ni-Si Alloys for the S-I Reactor-Hydrogen Production Process Interface (open access)

Ni-Si Alloys for the S-I Reactor-Hydrogen Production Process Interface

The overall goal of this project was to develop Ni-Si alloys for use in vessels to contain hot, pressurized sulfuric acid. The application was to be in the decomposition loop of the thermochemical cycle for production of hydrogen.
Date: January 21, 2010
Creator: Newkirk, Joseph W. & Brow, Richard K.
Object Type: Report
System: The UNT Digital Library
Armenia, Azerbaijan, and Georgia: Political Developments and Implications for U.S. Interests (open access)

Armenia, Azerbaijan, and Georgia: Political Developments and Implications for U.S. Interests

his report discusses the history and political background of Armenia, Azerbaijan, and Georgia since breaking away from the former Soviet Union at the end of 1991. It looks at key issues for the 112th Congress including economies, energy, regional politics, local crime, and terrorism.
Date: December 21, 2010
Creator: Nichol, Jim
Object Type: Report
System: The UNT Digital Library
Changes in the Arctic: Background and Issues for Congress (open access)

Changes in the Arctic: Background and Issues for Congress

This report provides an overview of Arctic-related issues for Congress, and refers readers to more in-depth CRS reports on specific Arctic-related issues. Congressional readers with questions about an issue discussed in this report should contact the author or authors of the section discussing that issue. The authors are identified by footnote at the start of each section.
Date: July 21, 2010
Creator: O'Rourke, Ronald
Object Type: Report
System: The UNT Digital Library
Coast Guard Polar Icebreaker Modernization: Background, Issues, and Options for Congress (open access)

Coast Guard Polar Icebreaker Modernization: Background, Issues, and Options for Congress

This report provides background information and issues for Congress on the modernization of the Coast Guard's polar icebreaker fleet, which performs a variety of missions supporting U.S. interests in polar regions.
Date: July 21, 2010
Creator: O'Rourke, Ronald
Object Type: Report
System: The UNT Digital Library
Navy Littoral Combat Ship (LCS) Program: Background, Issues, and Options for Congress (open access)

Navy Littoral Combat Ship (LCS) Program: Background, Issues, and Options for Congress

This report provides background information and potential issues for Congress on the Littoral Combat Ship (LCS), a relatively inexpensive Navy surface combatant equipped with modular "plug-and-fight" mission packages. The Navy's proposed FY2012 budget requests funding for the procurement of four LCSs. Current issues for Congress concerning the LCS program include changes or potential changes to the composition of LCS mission modules announced by the Navy in January 2011, the combat survivability of the LCS, and hull cracking on LCS-1. Congress's decisions on the LCS program could affect Navy capabilities and funding requirements, and the shipbuilding industrial base.
Date: June 21, 2010
Creator: O'Rourke, Ronald
Object Type: Report
System: The UNT Digital Library
Navy Ship Names: Background for Congress (open access)

Navy Ship Names: Background for Congress

This report discusses the process of naming Navy ships, which have traditionally been chosen and announced by the Secretary of the Navy. Congress in recent years has proposed, and sometimes passed, legislation regarding the naming of specific ships.
Date: July 21, 2010
Creator: O'Rourke, Ronald
Object Type: Report
System: The UNT Digital Library
Veterans Medical Care: FY2010 Appropriations (open access)

Veterans Medical Care: FY2010 Appropriations

This report focuses on funding for the Veterans Health Administration (VHA). The VHA is primarily a direct service provider of primary care, specialized care, and related medical and social support services to veterans through the nation's largest integrated health care system. Eligibility for VA health care is based primarily on previous military service, disability, and income.
Date: January 21, 2010
Creator: Panangala, Sidath V.
Object Type: Report
System: The UNT Digital Library
Housing for Persons Living with HIV/AIDS (open access)

Housing for Persons Living with HIV/AIDS

This report discusses the creation of the Housing Opportunities for Persons with AIDS (HOPWA) Program, which was created to alleviate the difficulties that many individuals with acquired immunodeficiency syndrome (AIDS) have finding affordable, stable housing. It also looks at distributions of HOPWA funds, including eligibility and eligible uses for such funding.
Date: January 21, 2010
Creator: Perl, Libby
Object Type: Report
System: The UNT Digital Library
Evaluation of Efficiency Activities in the Industrial Sector Undertaken in Response to Greenhouse Gas Emission Reduction Targets (open access)

Evaluation of Efficiency Activities in the Industrial Sector Undertaken in Response to Greenhouse Gas Emission Reduction Targets

The 2006 California Global Warming Solutions Act calls for reducing greenhouse gas (GHG) emissions to 1990 levels by 2020. Meeting this target will require action from all sectors of the California economy, including industry. The industrial sector consumes 25% of the energy used and emits 28% of the carbon dioxide (CO{sub 2}) produced in the state. Many countries around the world have national-level GHG reduction or energy-efficiency targets, and comprehensive programs focused on implementation of energy efficiency and GHG emissions mitigation measures in the industrial sector are essential for achieving their goals. A combination of targets and industry-focused supporting programs has led to significant investments in energy efficiency as well as reductions in GHG emissions within the industrial sectors in these countries. This project has identified program and policies that have effectively targeted the industrial sector in other countries to achieve real energy and CO{sub 2} savings. Programs in Ireland, France, The Netherlands, Denmark, and the UK were chosen for detailed review. Based on the international experience documented in this report, it is recommended that companies in California's industrial sector be engaged in a program to provide them with support to meet the requirements of AB32, The Global Warming Solution …
Date: May 21, 2010
Creator: Price, Lynn; de la Rue du Can, Stephane; Lu, Hongyou & Horvath, Arpad
Object Type: Report
System: The UNT Digital Library
Influence of molecular ordering on electrical and friction properties of omega-(trans-4-stilbene)alkylthiol self-assembled monolayers on Au (111) (open access)

Influence of molecular ordering on electrical and friction properties of omega-(trans-4-stilbene)alkylthiol self-assembled monolayers on Au (111)

The electrical and friction properties of omega-(trans-4-stilbene)alkylthiol self-assembled monolayers (SAMs) on Au(111) were investigated using atomic force microscopy (AFM) and near edge x-ray absorption fine structure spectroscopy (NEXAFS). The sample surface was uniformly covered with a molecular film consisting of very small grains. Well-ordered and flat monolayer islands were formed after the sample was heated in nitrogen at 120 oC for 1 h. While lattice resolved AFM images revealed a crystalline phase in the islands, the area between islands showed no order. The islands exhibit substantial reduction (50percent) in friction, supporting the existence of good ordering. NEXAFS measurements revealed an average upright molecular orientation in the film, both before and after heating, with a narrower tilt-angle distribution for the heated fim. Conductance-AFM measurements revealed a two orders of magnitude higher conductivity on the ordered islands than on the disordered phase. We propose that the conductance enhancement is a result of a better pi-pi stacking between the trans-stilbene molecular units as a result of improved ordering in islands.
Date: April 21, 2010
Creator: Qi, Yabing; Liu, Xiaosong; Hendriksen, B.L.M.; Navarro, V.; Park, Jeong Y.; Ratera, Imma et al.
Object Type: Article
System: The UNT Digital Library