Child Support Enforcement: Program Basics (open access)

Child Support Enforcement: Program Basics

In FY2004, the CSE program collected $21.9 billion in child support payments and served 15.9 million child support cases. However, the program still collects only 18% of child support obligations for which it has responsibility and collects payments for only 51% of its caseload.
Date: February 15, 2006
Creator: Solomon-Fears, Carmen
Object Type: Report
System: The UNT Digital Library
The Proposed U.S.-Panama Free Trade Agreement (open access)

The Proposed U.S.-Panama Free Trade Agreement

None
Date: February 15, 2006
Creator: Hornbeck, J. F.
Object Type: Report
System: The UNT Digital Library
"Sensitive but Unclassified" Information and Other Controls: Policy and Options for Scientific and Technical Information (open access)

"Sensitive but Unclassified" Information and Other Controls: Policy and Options for Scientific and Technical Information

This report traces the evolution of "sensitive but unclassified" or SBU-related controls; summarizes actions taken to protect certain types of scientific and technical information; describes critiques of some control policies; and summarizes proposals and actions, including congressional, executive and other initiatives, to clarify these issues and develop policies that serve various stakeholders. It also raises issues that may warrant further attention.
Date: February 15, 2006
Creator: Knezo, Genevieve J.
Object Type: Report
System: The UNT Digital Library
Persistant Organic Pollutants (POPs): Fact Sheet on Three International Agreements (open access)

Persistant Organic Pollutants (POPs): Fact Sheet on Three International Agreements

None
Date: February 15, 2006
Creator: Schierow, Linda-Jo
Object Type: Report
System: The UNT Digital Library
Russia's Cutoff of Natural Gas to Ukraine: Context and Implications (open access)

Russia's Cutoff of Natural Gas to Ukraine: Context and Implications

None
Date: February 15, 2006
Creator: Nichol, Jim; Woehrel, Steven & Gelb, Bernard A.
Object Type: Report
System: The UNT Digital Library
Tax Gap: Making Significant Progress in Improving Tax Compliance Rests on Enhancing Current IRS Techniques and Adopting New Legislative Actions (open access)

Tax Gap: Making Significant Progress in Improving Tax Compliance Rests on Enhancing Current IRS Techniques and Adopting New Legislative Actions

Testimony issued by the Government Accountability Office with an abstract that begins "The Internal Revenue Service's (IRS) most recent estimate of the difference between what taxpayers timely and accurately paid in taxes and what they owed was $345 billion. IRS estimates it will eventually recover some of this tax gap, resulting in an estimated net tax gap of $290 billion. The tax gap arises when taxpayers fail to comply with the tax laws by underreporting tax liabilities on tax returns; underpaying taxes due from filed returns; or nonfiling, which refers to the failure to file a required tax return altogether or in a timely manner. The Chairman and Ranking Minority Member of the Senate Committee on the Budget asked GAO to present information on the causes of and possible solutions to the tax gap. This testimony addresses the nature and extent of the tax gap and the significance of reducing the tax gap, including some steps that may assist with this challenging task. For context, this testimony also addressed GAO's most recent simulations of the long-term fiscal outlook and the need for a fundamental reexamination of major spending and tax policies and priorities."
Date: February 15, 2006
Creator: United States. Government Accountability Office.
Object Type: Text
System: The UNT Digital Library
Public Housing: Information on the Roles of HUD, Public Housing Agencies, Capital Markets, and Service Organizations (open access)

Public Housing: Information on the Roles of HUD, Public Housing Agencies, Capital Markets, and Service Organizations

Testimony issued by the Government Accountability Office with an abstract that begins "Under the Public Housing Program, the Department of Housing and Urban Development (HUD) and local public housing agencies (PHA) provide housing for low-income residents at rents they can afford. Today, over 3,000 PHAs administer approximately 1.2 million public housing units throughout the nation. First authorized in 1937, the program has undergone changes over the decades. The Quality Housing and Work Responsibility Act of 1998 increased managerial flexibility but also established new requirements for housing agencies. Some observers have questioned the program's ability to provide quality, affordable housing to the nation's neediest families. This testimony, which is based upon a number of reports that GAO has issued related to public housing since 2002, discusses the roles of (1) HUD (2) public housing agencies, (3) capital markets, and (4) community services organizations in the public housing system."
Date: February 15, 2006
Creator: United States. Government Accountability Office.
Object Type: Text
System: The UNT Digital Library
21st Century: Addressing Long-Term Fiscal Challenges Must Include a Re-examination of Mandatory Spending (open access)

21st Century: Addressing Long-Term Fiscal Challenges Must Include a Re-examination of Mandatory Spending

Testimony issued by the Government Accountability Office with an abstract that begins "This testimony discusses entitlement and other mandatory spending programs in light of our nation's long-term fiscal outlook and the challenges it poses for the budget and oversight processes. In our report entitled 21st Century Challenges: Reexamining the Base of the Federal Government, we presented illustrative questions for policy makers to consider as they carry out their responsibilities. These questions look across major areas of the budget and federal operations including discretionary and mandatory spending, and tax policies and programs. We hope that this report, among other things, will be used by various congressional committees as they consider which areas of government need particular attention and reconsideration. Congress will also receive more specific proposals, some of them will be presented within comprehensive agendas. Our report provides examples of the kinds of difficult choices the nation faces with regard to discretionary spending; mandatory spending, including entitlements; as well as tax policies and compliance activities."
Date: February 15, 2006
Creator: United States. Government Accountability Office.
Object Type: Text
System: The UNT Digital Library
Capitol Visitor Center: Results of Risk-based Analysis of Schedule and Cost (open access)

Capitol Visitor Center: Results of Risk-based Analysis of Schedule and Cost

Testimony issued by the Government Accountability Office with an abstract that begins "GAO testified before the Senate Subcommittee on the Legislative Branch, Committee on Appropriations to provide the results of a risk-based analysis of schedule and cost for the Capitol Visitor Center (CVC). Our remarks focused on (1) our assessment of the risks associated with the Architect of the Capitol's (AOC) December 2005 schedule, and our estimate of a time frame for opening the project to the public; and (2) the project's costs and funding, including the potential impact of scheduling issues that have arisen since the Subcommittee's November 16, 2005, hearing on the CVC project's schedule and cost."
Date: February 15, 2006
Creator: United States. Government Accountability Office.
Object Type: Text
System: The UNT Digital Library
Postal Reform Bills: A Side-by-Side Comparison of H.R. 22 and S. 662 (open access)

Postal Reform Bills: A Side-by-Side Comparison of H.R. 22 and S. 662

None
Date: February 15, 2006
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Emergency Communications: The Emergency Alert System (EAS) and All-Hazard Warnings (open access)

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

This report provides information about The Emergency Alert System (EAS) and All-Hazard Warnings on Emergency Communications.EAS is one of several federally managed warning systems.
Date: February 15, 2006
Creator: Moore, Linda K.
Object Type: Report
System: The UNT Digital Library
Soil and Water Conservation Issues (open access)

Soil and Water Conservation Issues

None
Date: February 15, 2006
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Trade Remedies: A Primer (open access)

Trade Remedies: A Primer

None
Date: February 15, 2006
Creator: unknown
Object Type: Report
System: The UNT Digital Library
The Digital TV Transition: A Brief Overview (open access)

The Digital TV Transition: A Brief Overview

This report briefly discusses key points about the digital TV transition process: background, the impact on broadcasting, spectrum policy, and recent legislative activity. The transition has two major policy components: (1) how best to move television broadcasters and their viewers to digital technology, and (2) radio frequency spectrum management and allocation. The public interest goals for these paths are not well aligned, presenting Congress with difficult choices for completing the transition.
Date: February 15, 2006
Creator: Kruger, Lennard G. & Moore, Linda K.
Object Type: Report
System: The UNT Digital Library
Contributions to the Genesis and Progress of ICF (open access)

Contributions to the Genesis and Progress of ICF

Inertial confinement fusion (ICF) has progressed from the detonation of large-scale fusion explosions initiated by atomic bombs in the early 1950s to final preparations for initiating small-scale fusion explosions with giant lasers. The next major step after ignition will be development of high performance targets that can be initiated with much smaller, lower cost lasers. In the 21st century and beyond, ICF's grand challenge is to develop practical power plants that generate low cost, clean, inexhaustible fusion energy. In this chapter, I first describe the origin in 1960-61 of ICF target concepts, early speculations on laser driven 'Thermonuclear Engines' for power production and rocket propulsion, and encouraging large-scale nuclear explosive experiments conducted in 1962. Next, I recall the 40-year, multi-billion dollar ignition campaign - to develop a matched combination of sufficiently high-performance implosion lasers and sufficiently stable targets capable of igniting small fusion explosions. I conclude with brief comments on the NIF ignition campaign and very high-performance targets, and speculations on ICF's potential in a centuries-long Darwinian competition of future energy systems. My perspectives in this chapter are those of a nuclear explosive designer, optimistic proponent of ICF energy, and Livermore Laboratory leader. The perspectives of Livermore's post 1970 laser …
Date: February 15, 2006
Creator: Nuckolls, J. H.
Object Type: Book
System: The UNT Digital Library
WRN Exonuclease Structure, Molecular Mechanism, and DNA EndProcessing Role (open access)

WRN Exonuclease Structure, Molecular Mechanism, and DNA EndProcessing Role

WRN is unique among the five human RecQ DNA helicases by having a functional exonuclease domain (WRN-exo) and being defective in the premature aging and cancer-related disorder Werner syndrome. Here, we characterize WRN-exo crystal structures, biochemical activity and participation in DNA end-joining. Metal ion complex structures, active site mutations and activity assays reveal a two-metal-ion mediated nuclease mechanism. The DNA end-binding Ku70/80 complex specifically stimulates WRN-exo activity, and structure-based mutational inactivation of WRN-exo alters DNA end-joining in human cells. We furthermore establish structural and biochemical similarities of WRN-exo to DnaQ family replicative proofreading exonucleases, with WRN-specific adaptations consistent with dsDNA specificity and functionally important conformational changes. These results indicate WRN-exo is a human DnaQ family member and support analogous proof-reading activities that are stimulated by Ku70/80 with implications for WRN functions in age related pathologies and maintenance of genomic integrity.
Date: February 15, 2006
Creator: Perry, J. Jefferson P.; Yannone, Steven M.; Holden, Lauren G.; Hitomi, Chiharu; Asaithamby, Aroumougame; Han, Seungil et al.
Object Type: Article
System: The UNT Digital Library
Targeted Gene Deletion Demonstrates that Cell Adhesion MoleculeICAM-4 is Critical for Erythroblastic Island Formation (open access)

Targeted Gene Deletion Demonstrates that Cell Adhesion MoleculeICAM-4 is Critical for Erythroblastic Island Formation

Erythroid progenitors differentiate in erythroblastic islands, bone marrow niches composed of erythroblasts surrounding a central macrophage. Evidence suggests that within islands adhesive interactions regulate erythropoiesis and apoptosis. We are exploring whether erythroid intercellular adhesion molecule-4 (ICAM-4), animmunoglobulin superfamily member, participates in island formation. Earlier, we identified alpha V integrins as ICAM-4 counter receptors. Since macrophages express alpha V, ICAM-4 potentially mediates island attachments. To test this, we generated ICAM-4 knockout mice and developed quantitative, live cell techniques for harvesting intact islands and for reforming islands in vitro. We observed a 47 percent decrease in islands reconstituted from ICAM-4 null marrow compared to wild type. We also found a striking decrease in islands formed in vivo in knockout mice. Further, peptides that block ICAM-4 alpha V adhesion produced a 53-57 percent decrease in reconstituted islands, strongly suggesting that ICAM-4 binding to macrophage alpha V functions in island integrity. Importantly, we documented that alpha V integrin is expressed in macrophages isolated from erythro blastic islands. Collectively, these data provide convincing evidence that ICAM-4 is critical in erythroblastic island formation via ICAM-4/alpha V adhesion and also demonstrate that the novel experimental strategies we developed will be valuable in exploring molecular mechanisms of erythroblastic …
Date: February 15, 2006
Creator: Lee, Gloria; Lo, Annie; Short, Sarah A.; Mankelow, Tosti J.; Spring, Frances; Parsons, Stephen F. et al.
Object Type: Article
System: The UNT Digital Library
Simulations And Experiments of Electron Beams Pre-Modulated at the Photo cathode (open access)

Simulations And Experiments of Electron Beams Pre-Modulated at the Photo cathode

The University of Maryland and the Source Development Laboratory at Brookhaven National Laboratory have been collaborating on a project that explores the use of electron beam pre-modulation at the cathode to control the longitudinal structure of the electron beam. This technique could be applied to creating deliberate modulations which can lead to the generation of terahertz radiation, or creating a smooth profile in order to suppress radiation. This paper focuses on simulations that explore some of the pre-modulated cases achieved experimentally.
Date: February 15, 2006
Creator: Neumann, J. G.; Fiorito, R. B.; O'Shea, P. G.; Carr, G. L.; Shaftan, T. V.; Sheehy, B. et al.
Object Type: Article
System: The UNT Digital Library
Multi-Alkali Photocathode Development at Brookhaven National Lab for Application in Superconducting Photoinjectors (open access)

Multi-Alkali Photocathode Development at Brookhaven National Lab for Application in Superconducting Photoinjectors

The development of a suitable photocathode for use in a high average current photoinjector at temperatures ranging from 273 K down to 2 K is a subject of considerable interest, and active research. The choice of photocathode material is often a trade-off made based on the quantum efficiency of the cathode material, the tolerance to adverse vacuum conditions, and the laser wavelength needed to produce photoelectrons. In this paper an overview of the BNL work to date on CsK{sub 2}Sb photocathodes on a variety of substrates, irradiated at multiple wavelengths, and at temperatures down to 170 K will be discussed. The application of this photocathode material into a SRF photoinjector will also be discussed.
Date: February 15, 2006
Creator: Burrill, A.; Ben-Zvi, Ilan; Pate, D.; Rao, T.; Segalov, Z. & Dowell, D.
Object Type: Article
System: The UNT Digital Library
An Experimental Investigation of the Structural Wave Scattering Due to Impedance Discontinuities on a Cylindrical Structure (open access)

An Experimental Investigation of the Structural Wave Scattering Due to Impedance Discontinuities on a Cylindrical Structure

Experimental, numerical, and analytical work has shown that the response of a shell to a distributed force wave possesses unique characteristics which are dependent on the nature of structure attached to the shell. Specific characteristics which influence the response are the distribution of the discontinuities around the circumference (periodic/aperiodic), the impedance of the discontinuities relative to that of the shell, and the type of impedance (mass or stiffness). Traditional shell theory predicts low frequency, radial-dominated structural mode shapes of a shell with a sinusoidal distribution of displacement amplitudes. Due to the orthogonal nature of these mode shapes, the response of the structure to a traveling radial force wave with sinusoidal content at a given harmonic is due solely to the response of the mode shape with harmonic content of the same order. Introduction of impedance discontinuities to a shell yield complex mode shapes, which may be characterized by the summation of several harmonic components. These modes are no longer orthogonal in the presence of discontinuities, yielding harmonic content across various modal orders. As a result, a purely sinusoidal forcing function can excite several modes of the structure. Structural scattering as discussed in this paper refers to the phenomena in which …
Date: February 15, 2006
Creator: Glotzbecker, RJ
Object Type: Thesis or Dissertation
System: The UNT Digital Library
New Ghost-Node Method for Linking Different Models with Varied Grid Refinement (open access)

New Ghost-Node Method for Linking Different Models with Varied Grid Refinement

A flexible, robust method for linking grids of locally refined models constructed with different numerical methods is needed to address a variety of hydrologic problems. This work outlines and tests a new ghost-node model-linking method for a refined ''child'' model that is contained within a larger and coarser ''parent'' model that is based on the iterative method of Mehl and Hill (2002, 2004). The method is applicable to steady-state solutions for ground-water flow. Tests are presented for a homogeneous two-dimensional system that has either matching grids (parent cells border an integer number of child cells; Figure 2a) or non-matching grids (parent cells border a non-integer number of child cells; Figure 2b). The coupled grids are simulated using the finite-difference and finite-element models MODFLOW and FEHM, respectively. The simulations require no alteration of the MODFLOW or FEHM models and are executed using a batch file on Windows operating systems. Results indicate that when the grids are matched spatially so that nodes and child cell boundaries are aligned, the new coupling technique has error nearly equal to that when coupling two MODFLOW models (Mehl and Hill, 2002). When the grids are non-matching, model accuracy is slightly increased over matching-grid cases. Overall, results …
Date: February 15, 2006
Creator: James, Scott C.; Dickinson, Jesse E.; Mehl, Steffen W.; Hill, Mary C.; Leake, Stanley A.; Zyvoloski, George A. et al.
Object Type: Report
System: The UNT Digital Library
Ferrocene-Based Nanoelectronics (open access)

Ferrocene-Based Nanoelectronics

Ferrocene-based molecular components for nanoelectronics offer a number of distinct advantages relative to all carbon frameworks due to metal-centered molecular states that should be closer in energy to the Fermi levels of the metal electrodes in metal / molecule / metal heterojunctions. Given this, the overall goal of the project was to investigate the conduction physics of a variety of proposed ferrocene diode / transistor designs in order to address the fundamental question; can electron transport within nm-length scale structures be modulated in a controlled fashion? During the funded period, substantial progress towards achieving this goal was made by surmounting a number of scientific and technical obstacles. More specifically, a concise and general synthetic route to several mono- and diferrocene dithiols and monothiols was achieved that now allows for the directed and controlled assembly of a variety of metal / molecule /metal test structures for the single molecule conductance measurements and the fabrication of self-assembled monolayers (SAMs) on Au(111) that are amenable to quantitative electrochemical characterization of electron-transfer rates. Most importantly, by using an electromigrated test structure, reproducible I/V data for one of the ferrocene dithiol molecules have been collected which exhibit surprisingly high conductance. Exceptional agreement of this result …
Date: February 15, 2006
Creator: Sita, Lawrence R.
Object Type: Report
System: The UNT Digital Library
Simulation of PEP-II Accelerator Backgrounds Using TURTLE (open access)

Simulation of PEP-II Accelerator Backgrounds Using TURTLE

We present studies of accelerator-induced backgrounds in the BaBar detector at the SLAC B-Factory, carried out using LPTURTLE, a modified version of the DECAY TURTLE simulation package. Lost-particle backgrounds in PEP-II are dominated by a combination of beam-gas bremstrahlung, beam-gas Coulomb scattering, radiative-Bhabha events and beam-beam blow-up. The radiation damage and detector occupancy caused by the associated electromagnetic shower debris can limit the usable luminosity. In order to understand and mitigate such backgrounds, we have performed a full program of beam-gas and luminosity-background simulations, that include the effects of the detector solenoidal field, detailed modeling of limiting apertures in both collider rings, and optimization of the betatron collimation scheme in the presence of large transverse tails.
Date: February 15, 2006
Creator: Barlow, R. J.; Fieguth, T.; Kozanecki, W.; Majewski, S. A.; Roudeau, P. & Stocchi, A.
Object Type: Article
System: The UNT Digital Library
The Sorption/Desorption Behavior of Uranium in Transport Studies Using Yucca Mountain Alluvium (open access)

The Sorption/Desorption Behavior of Uranium in Transport Studies Using Yucca Mountain Alluvium

Yucca Mountain, Nevada is the proposed site of a geologic repository for the disposal of spent nuclear fuel and high-level radioactive waste in the United States. In the event repository engineered barriers fail, the saturated alluvium located south of Yucca Mountain is expected to serve as a natural barrier to the migration of radionuclides to the accessible environment. The purpose of this study is to improve the characterization of uranium retardation in the saturated zone at Yucca Mountain to support refinement of an assessment model. The distribution of uranium desorption rates from alluvium obtained from Nye County bore holes EWDP-19IM1, EWDP-10SA, EWDP-22SA were studied to address inconsistencies between results from batch sorption and column transport experiments. The alluvium and groundwater were characterized to better understand the underlying mechanisms of the observed behavior. Desorption rate constants were obtained using an activity based mass balance equation and column desorption experiments were analyzed using a mathematical model utilizing multiple sorption sites with different first-order forward and reverse reaction rates. The uranium desorption rate constants decreased over time, suggesting that the alluvium has multiple types of active sorption sites with different affinities for uranium. While a significant fraction of the initially sorbed uranium desorbed …
Date: February 15, 2006
Creator: Scism, C. D.
Object Type: Thesis or Dissertation
System: The UNT Digital Library