Theoretical study of the structure, energetics, and dynamics of silicon and carbon systems using tight-binding approaches (open access)

Theoretical study of the structure, energetics, and dynamics of silicon and carbon systems using tight-binding approaches

Semiempirical interatomic potentials are developed for silicon and carbon by modeling the total energy of the system using tight-binding approaches. The parameters of the models were obtained by fitting to results from accurate first-principles Local Density Functional calculations. Applications to the computation of phonons as a function of volume for diamond-structured silicon and carbon and the thermal expansions for silicon and diamond yields results which agree well with experiment. The physical origin of the negative thermal expansion observed in silicon is explained. A tight-binding total energy model is generated capable of describing carbon systems with a variety of atomic coordinations and topologies. The model reproduces the total energy versus volume curves of various carbon polytypes as well as phonons and elastic constants of diamond and graphite. The model has also been used in the molecular-dynamics simulation of the properties of carbon clusters. The calculated ground-state geometries of small clusters (C{sub 2}--C{sub 10}) correlates well with results from accurate quantum chemical calculations, and the structural trend of clusters from C{sub 2} to C{sub 60} are investigated. 67 refs., 19 figs.
Date: October 25, 1991
Creator: Xu, Chunhui.
Object Type: Report
System: The UNT Digital Library
Monthly energy review, October 1991. [Contains glossary] (open access)

Monthly energy review, October 1991. [Contains glossary]

This report presents current data on production, consumption, stocks, imports, exports, and prices of the principal energy commodities in the United States. Also included are data on international production of crude oil, consumption of petroleum products, petroleum stocks, and production of electricity from nuclear-powered facilities. 36 figs., 57 tabs.
Date: October 25, 1991
Creator: unknown
Object Type: Report
System: The UNT Digital Library
In situ instrumentation: final report of a joint EE/ME group study. [Economic utilization of oil shale, some coal deposits and geothermal resources may depend on in situ processing] (open access)
Time-dependent properties of fiber composites for energy-storage flywheels (open access)

Time-dependent properties of fiber composites for energy-storage flywheels

Time-dependent deformation and time-dependent strength are being characterized for several candidate polymeric composites for flywheels. This presentation highlights the motivation and the philosophy of the characterization adopted by the authors in establishing the ongoing programs at LLL. This overview is intended to provide a basis for inferring the type of enginering data being generated for different aspects of flywheel design. The details of these data can be obtained from the published reports and articles. Two aspects of flywheel design data are addressed: those dealing with time-dependent statistical strength, and those dealing with deformation and strength under time-varying history.
Date: October 25, 1977
Creator: Wu, E.M. & Penn, L.S.
Object Type: Article
System: The UNT Digital Library
Navy Aegis Ballistic Missile Defense (BMD) Program: Background and Issues for Congress (open access)

Navy Aegis Ballistic Missile Defense (BMD) Program: Background and Issues for Congress

Report that discusses the funding for the growth of the Aegis ballistic missile defense (BMD) program. The Aegis BMD program, which is carried out by the Missile Defense Agency (MDA) and the Navy, gives Navy Aegis cruisers and destroyers a capability for conducting BMD operations.
Date: October 25, 2012
Creator: O'Rourke, Ronald
Object Type: Report
System: The UNT Digital Library
House Committee Chairs: Considerations, Decisions, and Actions as One Congress Ends and a New Congress Begins (open access)

House Committee Chairs: Considerations, Decisions, and Actions as One Congress Ends and a New Congress Begins

Report that addresses some of the critical matters a House committee chair confronts from the time of the early organization meetings in November to approximately the spring district work-period in March or April.
Date: October 25, 2012
Creator: Schneider, Judy & Koempel, Michael L.
Object Type: Report
System: The UNT Digital Library
Climate Change and Existing Law: A Survey of Legal Issues Past, Present, and Future (open access)

Climate Change and Existing Law: A Survey of Legal Issues Past, Present, and Future

Report that surveys existing law for legal issues that have arisen, or may arise in the future, on account of climate change and government responses thereto.
Date: October 25, 2012
Creator: Meltz, Robert
Object Type: Report
System: The UNT Digital Library
Constitutionality of Retroactive Tax Legislation (open access)

Constitutionality of Retroactive Tax Legislation

Report that examines the constitutional provisions that might be implicated by retroactive tax legislation, including legislation that seems intended to punish past behavior.
Date: October 25, 2012
Creator: Lunder, Erika K.; Meltz, Robert & Thomas, Kenneth R.
Object Type: Report
System: The UNT Digital Library
Guam: U.S. Defense Deployments (open access)

Guam: U.S. Defense Deployments

Report that provides a basic overview of the island of Guam, including population and location, as well as the strategic significance of Guam for boosting U.S. deterrence and power projection in Asia.
Date: October 25, 2012
Creator: Kan, Shirley A.
Object Type: Report
System: The UNT Digital Library
Army Drawdown and Restructuring: Background and Issues for Congress (open access)

Army Drawdown and Restructuring: Background and Issues for Congress

This report discusses the new defense strategy, which was unveiled by senior DOD leadership based on a review of potential future security challenges, current defense strategy, and budgetary constraints. This strategy will rebalance the Army's global posture and presence, emphasizing where potential problems are likely to arise, such as the Asia-Pacific region and the Middle East
Date: October 25, 2013
Creator: Feickert, Andrew
Object Type: Report
System: The UNT Digital Library
Cybersecurity: Authoritative Reports and Resources (open access)

Cybersecurity: Authoritative Reports and Resources

This report provides links to cybersecurity hearings and legislation under consideration in the 113th Congress and those considered in the 112th Congress, as well as executive orders and presidential directives, data and statistics, glossaries, and authoritative reports.
Date: October 25, 2013
Creator: Tehan, Rita
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

This report discusses the history and political background of Armenia, Azerbaijan, and Georgia since their breakaway 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: October 25, 2013
Creator: Nichol, Jim
Object Type: Report
System: The UNT Digital Library
Introducing a Public Advocate into the Foreign Intelligence Surveillance Act's Courts: Select Legal Issues (open access)

Introducing a Public Advocate into the Foreign Intelligence Surveillance Act's Courts: Select Legal Issues

This report explores government surveillance act and other difficult constitutional issues prompted by the idea of including a new adversary in established under the Foreign Intelligence Surveillance Act of 1978 (FISA) FISA court proceedings.
Date: October 25, 2013
Creator: Nolan, Andrew; Thompson, Richard M., II & Chu, Vivian S.
Object Type: Report
System: The UNT Digital Library
Medicare Program Integrity: Contractors Reported Generating Savings, but CMS Could Improve Its Oversight (open access)

Medicare Program Integrity: Contractors Reported Generating Savings, but CMS Could Improve Its Oversight

A letter report issued by the Government Accountability Office with an abstract that begins "The Centers for Medicare and Medicaid Services (CMS) paid its Zone Program Integrity Contractors (ZPIC) about $108 million in 2012. ZPICs reported spending most of this funding on fraud case development, primarily for investigative staff, who in 2012 reported conducting about 3,600 beneficiary interviews, almost 780 onsite inspections, and reviews of more than 200,000 Medicare claims."
Date: October 25, 2013
Creator: United States. Government Accountability Office.
Object Type: Report
System: The UNT Digital Library
Federal Facilities: Selected Facilities' Emergency Plans Generally Reflect Federal Guidance (open access)

Federal Facilities: Selected Facilities' Emergency Plans Generally Reflect Federal Guidance

A letter report issued by the Government Accountability Office with an abstract that begins "Federal agencies occupying facilities owned or leased by the General Services Administration (GSA) are responsible for preparing and maintaining occupant emergency plans (OEP), with assistance or guidance from the Federal Protective Service (FPS) and others, and the majority of selected federal facilities' OEPs GAO reviewed reflect federal guidance. As required by federal regulations, all 20 selected facilities had OEPs and had designated officials, who are responsible for maintaining OEPs and initiating action according to the OEP in the event of an emergency, including the evacuation of facility occupants. Consistent with federal guidance, officials at 19 of the 20 selected facilities reported that they review and update OEPs at least annually, and officials at 1 facility said they were in the process of updating their OEP. When requested, FPS provides OEP guidance, such as templates to facility officials. Officials at 14 facilities reported using FPS guidance or feedback for their OEPs, officials at 1 facility reported not using FPS guidance, and officials at 5 facilities said they used their own agency's guidance. FPS also checks OEPs during periodic facility security assessments--conducted at least every 3 to 5 …
Date: October 25, 2013
Creator: United States. Government Accountability Office.
Object Type: Report
System: The UNT Digital Library
National Laboratories: DOE Needs to Improve Oversight of Work Performed for Non-DOE Entities (open access)

National Laboratories: DOE Needs to Improve Oversight of Work Performed for Non-DOE Entities

A letter report issued by the Government Accountability Office with an abstract that begins "In fiscal years 2008 through 2012, the Department of Energy (DOE) performed about $2 billion annually of Work for Others (WFO) projects, as measured by the costs incurred. Although the amount of WFO performed has remained relatively constant over the last 5 years overall, WFO as a percentage of the total work performed at the laboratories--measured in total laboratory costs incurred--has declined from 17 percent in fiscal year 2008 to about 13 percent in fiscal year 2012. In fiscal year 2012, the WFO program included more than 6,500 projects. About 88 percent of this work was for other federal agencies, with the majority of it performed for the Department of Defense. For example, one project for the Army applies a laboratory's expertise in laser decontamination of surfaces to develop a system that will remove chemical agent residues from equipment. The remaining WFO work was sponsored by nonfederal entities, including state and local governments, universities, private industry, and foreign entities."
Date: October 25, 2013
Creator: United States. Government Accountability Office.
Object Type: Report
System: The UNT Digital Library
Some Improvements Have Been Made in DOD's Annual Training Range Reporting but It Still Fails to Fully Address Congressional Requirements (open access)

Some Improvements Have Been Made in DOD's Annual Training Range Reporting but It Still Fails to Fully Address Congressional Requirements

Correspondence issued by the Government Accountability Office with an abstract that begins "A fundamental military readiness principle is that the military must train as it intends to fight, and military training ranges provide the primary means to accomplish this principle. To successfully accomplish today's missions, U.S. forces are conducting significantly more complex operations, requiring increased joint training and interoperability between and among the military services, combatant commands, and other Department of Defense (DOD) and non-DOD organizations. For some time, senior DOD and military service officials have reported that they face increasing difficulties in carrying out realistic training at military installations due to training constraints, such as those resulting from encroachment. In recent years, we have reported on these training constraints and identified the need for an integrated, readily accessible inventory of training ranges, capacities, and capabilities so that commanders across the services can schedule the best available resources to provide the required training; a comprehensive plan that includes goals, timelines, projected costs, and a clear assignment of responsibilities to address encroachment on military training ranges; and a more comprehensive approach for addressing deficiencies to ensure that ranges are adequately sustained and modernized in order to accomplish the department's transformation goals …
Date: October 25, 2005
Creator: United States. Government Accountability Office.
Object Type: Text
System: The UNT Digital Library
Information Technology: Improvements for Acquisition of Customs Trade Processing System Continue, but Further Efforts Needed to Avoid More Cost and Schedule Shortfalls (open access)

Information Technology: Improvements for Acquisition of Customs Trade Processing System Continue, but Further Efforts Needed to Avoid More Cost and Schedule Shortfalls

A letter report issued by the Government Accountability Office with an abstract that begins "The Department of Homeland Security (DHS) established the Automated Commercial Environment (ACE) program to replace and supplement existing cargo processing technology. According to the fiscal year 2007 DHS appropriations act, DHS is to develop and submit an expenditure plan for ACE that satisfies certain conditions, including being reviewed by GAO. GAO reviewed the plan to (1) determine whether the expenditure plan satisfies the legislative conditions, (2) determine the status of 15 open GAO recommendations, and (3) provide observations about the expenditure plan and DHS's management of the program. To address the mandate, GAO assessed plans and related documentation against federal guidelines and industry standards and interviewed the appropriate DHS officials."
Date: October 25, 2007
Creator: United States. Government Accountability Office.
Object Type: Report
System: The UNT Digital Library
Military Readiness: DOD Needs to Identify and Address Gaps and Potential Risks in Program Strategies and Funding Priorities for Selected Equipment (open access)

Military Readiness: DOD Needs to Identify and Address Gaps and Potential Risks in Program Strategies and Funding Priorities for Selected Equipment

A letter report issued by the Government Accountability Office with an abstract that begins "With continued heavy military involvement in operations in Iraq and Afghanistan, the Department of Defense (DOD) is spending billions of dollars sustaining or replacing its inventory of key equipment items while also planning to spend billions of dollars to develop and procure new systems to transform the department's warfighting capabilities. GAO developed a red, yellow, green assessment framework to (1) assess the condition of 30 selected equipment items from across the four military services, and (2) determine the extent to which DOD has identified near- and long-term program strategies and funding plans to ensure that these items can meet defense requirements. GAO selected these items based on input from the military services, congressional committees, and our prior work. These 30 equipment items included 18 items that were first assessed in GAO's 2003 report."
Date: October 25, 2005
Creator: United States. Government Accountability Office.
Object Type: Report
System: The UNT Digital Library
Moving Illegal Proceeds: Challenges Exist in the Federal Government's Effort to Stem Cross-Border Currency Smuggling (open access)

Moving Illegal Proceeds: Challenges Exist in the Federal Government's Effort to Stem Cross-Border Currency Smuggling

A letter report issued by the Government Accountability Office with an abstract that begins "U.S. Customs and Border Protection (CBP) is the lead federal agency responsible for inspecting travelers who seek to smuggle large volumes of cash--called bulk cash--when leaving the country through land ports of entry. It is estimated that criminals smuggle $18 billion to $39 billion a year in bulk cash across the southwest border. The Financial Crimes Enforcement Network (FinCEN) is responsible for reducing the risk of cross-border smuggling of funds through the use of devices called stored value, such as prepaid cards. GAO was asked to examine (1) the extent of actions taken by CBP to stem the flow of bulk cash leaving the country and any challenges that remain, (2) the regulatory gaps, if any, of cross-border reporting and other anti-money laundering requirements of stored value, and (3) if gaps exist, the extent to which FinCEN has addressed them. To conduct its work, GAO observed outbound operations at five land ports of entry. GAO also reviewed statutes, rules, and other information for stored value. This is a public version of a law enforcement sensitive report that GAO issued in September 2010. Information CBP deemed sensitive …
Date: October 25, 2010
Creator: United States. Government Accountability Office.
Object Type: Report
System: The UNT Digital Library
Nuclear Weapons: Information on Safety Concerns with the Uranium Processing Facility (open access)

Nuclear Weapons: Information on Safety Concerns with the Uranium Processing Facility

Correspondence issued by the Government Accountability Office with an abstract that begins "The Defense Nuclear Facilities Safety Board (Safety Board) has raised concerns with the National Nuclear Security Administration's (NNSA) plans to construct the Uranium Processing Facility (UPF), and NNSA has taken steps to address many of these concerns. Specifically:"
Date: October 25, 2013
Creator: United States. Government Accountability Office.
Object Type: Text
System: The UNT Digital Library
2020 Census: Additional Actions Could Strengthen Future Census Test Designs (open access)

2020 Census: Additional Actions Could Strengthen Future Census Test Designs

A letter report issued by the Government Accountability Office with an abstract that begins ""
Date: October 25, 2013
Creator: United States. Government Accountability Office.
Object Type: Report
System: The UNT Digital Library
Supply Chain Security: CBP Needs to Conduct Regular Assessments of Its Cargo Targeting System (open access)

Supply Chain Security: CBP Needs to Conduct Regular Assessments of Its Cargo Targeting System

A letter report issued by the Government Accountability Office with an abstract that begins "U.S. Customs and Border Protection (CBP), within the Department of Homeland Security (DHS), employs a risk-based approach that uses the Automated Targeting System (ATS) and other tools to identify (target) maritime cargo shipments for further examination. ATS is a web-based enforcement and decision support system that includes a set of rules to assess the risk level for each arriving cargo shipment. This set of rules is referred to as the maritime national security weight set (weight set) because each rule in the set has a specific weighted value assigned to it. CBP classifies the risk scores from the weight set as low, medium, or high risk. CBP policy states that a shipment's risk score is to determine, in part, actions taken by CBP officers (targeters) at the ports. Specifically, targeters are generally required to review shipment data for all medium-risk and high-risk shipments and hold high-risk shipments for examination. The risk score, however, is not the sole factor that determines whether a targeter reviews the data for a shipment or whether CBP examines a shipment. In particular, targeters at each of the six ports GAO visited …
Date: October 25, 2012
Creator: United States. Government Accountability Office.
Object Type: Report
System: The UNT Digital Library
Critical Infrastructure Protection: An Implementation Strategy Could Advance DHS's Coordination of Resilience Efforts across Ports and Other Infrastructure (open access)

Critical Infrastructure Protection: An Implementation Strategy Could Advance DHS's Coordination of Resilience Efforts across Ports and Other Infrastructure

A letter report issued by the Government Accountability Office with an abstract that begins "The Department of Homeland Security (DHS) is developing a resilience policy, but an implementation strategy is a key next step that could help strengthen DHS resilience efforts. DHS defines resilience as the ability to resist, absorb, recover from, or adapt to adversity, and some high-level documents currently promote resilience as a key national goal. Specifically, two key White House documents emphasize resilience on a national level--the 2011 Presidential Policy Directive 8 and the 2012 National Strategy for Global Supply Chain Security. Since 2009, DHS has emphasized the concept of resilience and is currently in the process of developing a resilience policy, the initial steps of which have included creating two internal entities--the Resilience Integration Team and the Office of Resilience Policy (ORP). According to ORP officials, they saw a need to establish a policy that provides component agencies with a single, consistent, departmentwide understanding of resilience that clarifies and consolidates resilience concepts from high-level guiding documents, and helps components understand how their activities address DHS's proposed resilience objectives. ORP officials hope to have an approved policy in place later this year. However, DHS officials stated that …
Date: October 25, 2012
Creator: United States. Government Accountability Office.
Object Type: Report
System: The UNT Digital Library