Algorithm Summary and Evaluation: Automatic Implementation of Ringdown Analysis for Electromechanical Mode Identification from Phasor Measurements (open access)

Algorithm Summary and Evaluation: Automatic Implementation of Ringdown Analysis for Electromechanical Mode Identification from Phasor Measurements

Small signal stability problems are one of the major threats to grid stability and reliability. Prony analysis has been successfully applied on ringdown data to monitor electromechanical modes of a power system using phasor measurement unit (PMU) data. To facilitate an on-line application of mode estimation, this paper develops a recursive algorithm for implementing Prony analysis and proposed an oscillation detection method to detect ringdown data in real time. By automatically detecting ringdown data, the proposed method helps guarantee that Prony analysis is applied properly and timely on the ringdown data. Thus, the mode estimation results can be performed reliably and timely. The proposed method is tested using Monte Carlo simulations based on a 17-machine model and is shown to be able to properly identify the oscillation data for on-line application of Prony analysis. In addition, the proposed method is applied to field measurement data from WECC to show the performance of the proposed algorithm.
Date: February 28, 2010
Creator: Zhou, Ning; Huang, Zhenyu; Tuffner, Francis K.; Jin, Shuangshuang; Lin, Jenglung & Hauer, Matthew L.
Object Type: Report
System: The UNT Digital Library
ARM Climate Research Facility Instrumentation Status and Information January 2010 (open access)

ARM Climate Research Facility Instrumentation Status and Information January 2010

The purpose of this report is to provide a concise but comprehensive overview of Atmospheric Radiation Measurement Climate Research Facility instrumentation status. The report is divided into the following five sections: (1) new instrumentation in the process of being acquired and deployed, (2) field campaigns, (3) existing instrumentation and progress on improvements or upgrades, (4) proposed future instrumentation, and (5) Small Business Innovation Research instrument development.
Date: February 28, 2010
Creator: Voyles, J. W.
Object Type: Report
System: The UNT Digital Library
Efficient Windows Collaborative: Research Tool Dissemination to Increase Energy Efficient Fenestration Product Penetration (open access)

Efficient Windows Collaborative: Research Tool Dissemination to Increase Energy Efficient Fenestration Product Penetration

The project goals covered both the residential and commercial windows markets and involved a range of audiences such as window manufacturers, builders, homeowners, design professionals, utilities, and public agencies. Essential goals included: (1) Creation of 'Master Toolkits' of information that integrate diverse tools, rating systems, and incentive programs, customized for key audiences such as window manufacturers, design professionals, and utility programs. (2) Delivery of education and outreach programs to multiple audiences through conference presentations, publication of articles for builders and other industry professionals, and targeted dissemination of efficient window curricula to professionals and students. (3) Design and implementation of mechanisms to encourage and track sales of more efficient products through the existing Window Products Database as an incentive for manufacturers to improve products and participate in programs such as NFRC and ENERGY STAR. (4) Development of utility incentive programs to promote more efficient residential and commercial windows. Partnership with regional and local entities on the development of programs and customized information to move the market toward the highest performing products. An overarching project goal was to ensure that different audiences adopt and use the developed information, design and promotion tools and thus increase the market penetration of energy efficient fenestration …
Date: February 28, 2010
Creator: Alliance to Save Energy (U.S.)
Object Type: Report
System: The UNT Digital Library
Hanford Site Annual Report Radiological Dose Calculation Upgrade Evaluation (open access)

Hanford Site Annual Report Radiological Dose Calculation Upgrade Evaluation

Operations at the Hanford Site, Richland, Washington, result in the release of radioactive materials to offsite residents. Site authorities are required to estimate the dose to the maximally exposed offsite resident. Due to the very low levels of exposure at the residence, computer models, rather than environmental samples, are used to estimate exposure, intake, and dose. A DOS-based model has been used in the past (GENII version 1.485). GENII v1.485 has been updated to a Windows®-based software (GENII version 2.08). Use of the updated software will facilitate future dose evaluations, but must be demonstrated to provide results comparable to those of GENII v1.485. This report describes the GENII v1.485 and GENII v2.08 dose exposure, intake, and dose estimates for the maximally exposed offsite resident reported for calendar year 2008. The GENII v2.08 results reflect updates to implemented algorithms. No two environmental models produce the same results, as was again demonstrated in this report. The aggregated dose results from 2008 Hanford Site airborne and surface water exposure scenarios provide comparable dose results. Therefore, the GENII v2.08 software is recommended for future offsite resident dose evaluations.
Date: February 28, 2010
Creator: Snyder, Sandra F.
Object Type: Report
System: The UNT Digital Library
Integrated Control of Next Generation Power System (open access)

Integrated Control of Next Generation Power System

Control methodologies provide the necessary data acquisition, analysis and corrective actions needed to maintain the state of an electric power system within acceptable operating limits. These methods are primarily software-based algorithms that are nonfunctional unless properly integrated with system data and the appropriate control devices. Components of the control of power systems today include protective relays, supervisory control and data acquisition (SCADA), distribution automation (DA), feeder automation, software agents, sensors, control devices and communications. Necessary corrective actions are still accomplished using large electromechanical devices such as vacuum, oil and gas-insulated breakers, capacitor banks, regulators, transformer tap changers, reclosers, generators, and more recently FACTS (flexible AC transmission system) devices. The recent evolution of multi-agent system (MAS) technologies has been reviewed and effort made to integrate MAS into next generation power systems. A MAS can be defined as “…a loosely-coupled network of problem solvers that work together to solve problems that are beyond their individual capabilities…”. These problem solvers, often called agents, are autonomous and may be heterogeneous in nature. This project has shown that a MAS has significant advantages over a single, monolithic, centralized problem solver for next generation power systems. Various communication media are being used in the electric power …
Date: February 28, 2010
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Singapore's Zero-Energy Building's daylight monitoring system (open access)

Singapore's Zero-Energy Building's daylight monitoring system

A setup to monitor the daylighting performance of different glazing types in Singapore is presented. The glazing is installed in the facade of four dedicated testing chambers in BCAA's Zero Energy Building in Singapore. These test rooms are equipped with sensors that both record illuminances on the work plane, and luminances as seen by occupants. The physical and logical design of the monitoring system is presented. Criteria to assess the daylighting performance are introduced, and initial results of the work in progress are presented.
Date: February 28, 2010
Creator: Grobe, Lars; Wittkopf, Stephen; Pandey, Anupama Rana; Xiaoming, Yang; Seng, Ang Kian; Scartezzini, Jean-Louis et al.
Object Type: Article
System: The UNT Digital Library
Thermodynamically Tuned Nanophase Materials for reversible Hydrogen storage (open access)

Thermodynamically Tuned Nanophase Materials for reversible Hydrogen storage

This program was devoted to significantly extending the limits of hydrogen storage technology for practical transportation applications. To meet the hydrogen capacity goals set forth by the DOE, solid-state materials consisting of light elements were developed. Many light element compounds are known that have high capacities. However, most of these materials are thermodynamically too stable, and they release and store hydrogen much too slowly for practical use. In this project we developed new light element chemical systems that have high hydrogen capacities while also having suitable thermodynamic properties. In addition, we developed methods for increasing the rates of hydrogen exchange in these new materials. The program has significantly advanced (1) the application of combined hydride systems for tuning thermodynamic properties and (2) the use of nanoengineering for improving hydrogen exchange. For example, we found that our strategy for thermodynamic tuning allows both entropy and enthalpy to be favorably adjusted. In addition, we demonstrated that using porous supports as scaffolds to confine hydride materials to nanoscale dimensions could improve rates of hydrogen exchange by > 50x. Although a hydrogen storage material meeting the requirements for commercial development was not achieved, this program has provided foundation and direction for future efforts. More …
Date: February 28, 2010
Creator: Liu, Ping & Vajo, John J.
Object Type: Report
System: The UNT Digital Library
Time-windows-based filtering method for near-surface detection of leakage from geologic carbon sequestration sites (open access)

Time-windows-based filtering method for near-surface detection of leakage from geologic carbon sequestration sites

We use process-based modeling techniques to characterize the temporal features of natural biologically controlled surface CO{sub 2} fluxes and the relationships between the assimilation and respiration fluxes. Based on these analyses, we develop a signal-enhancing technique that combines a novel time-window splitting scheme, a simple median filtering, and an appropriate scaling method to detect potential signals of leakage of CO{sub 2} from geologic carbon sequestration sites from within datasets of net near-surface CO{sub 2} flux measurements. The technique can be directly applied to measured data and does not require subjective gap filling or data-smoothing preprocessing. Preliminary application of the new method to flux measurements from a CO{sub 2} shallow-release experiment appears promising for detecting a leakage signal relative to background variability. The leakage index of ?2 was found to span the range of biological variability for various ecosystems as determined by observing CO{sub 2} flux data at various control sites for a number of years.
Date: February 28, 2010
Creator: Pan, L.; Lewicki, J. L.; Oldenburg, C. M. & Fischer, M. L.
Object Type: Article
System: The UNT Digital Library
Analysis of the Younger Dryas Impact Layer (open access)

Analysis of the Younger Dryas Impact Layer

We have uncovered a thin layer of magnetic grains and microspherules, carbon spherules, and glass-like carbon at nine sites across North America, a site in Belgium, and throughout the rims of 16 Carolina Bays. It is consistent with the ejecta layer from an impact event and has been dated to 12.9 ka BP coinciding with the onset of Younger Dryas (YD) cooling and widespread megafaunal extinctions in North America. At many locations the impact layer is directly below a black mat marking the sudden disappearance of the megafauna and Clovis people. The distribution pattern of the Younger Dryas boundary (YDB) ejecta layer is consistent with an impact near the Great Lakes that deposited terrestrial-like ejecta near the impact site and unusual, titanium-rich projectile-like ejecta further away. High water content associated with the ejecta, up to 28 at. percent hydrogen (H), suggests the impact occurred over the Laurentide Ice Sheet. YDB microspherules and magnetic grains are highly enriched in TiO{sub 2}. Magnetic grains from several sites are enriched in iridium (Ir), up to 117 ppb. The TiO{sub 2}/FeO, K/Th, TiO{sub 2}/Zr, Al{sub 2}O{sub 3}/FeO+MgO, CaO/Al{sub 2}O{sub 3}, REE/ chondrite, FeO/MnO ratios and SiO{sub 2}, Na{sub 2}O, K{sub 2}O, Cr{sub 2}O{sub 3}, …
Date: February 27, 2010
Creator: Firestone, Richard B.; West, Allen; Revay, Zsolt; Hagstrum, Jonathon T,; Belgya, Thomas; Hee, Shane S. Que et al.
Object Type: Article
System: The UNT Digital Library
Iran Sanctions (open access)

Iran Sanctions

This report focuses on the United States' relationship with Iran and how the Obama Administration is handling prior administrations' economic sanctions against Iran. The Obama Administration's policy approach toward Iran has contrasted with the Bush Administration's by attempting to couple the imposition of sanctions to an active and direct U.S. effort to negotiate with Iran on the nuclear issue.
Date: February 27, 2010
Creator: Katzman, Kenneth
Object Type: Report
System: The UNT Digital Library
Afghanistan Casualties: Military Forces and Civilians (open access)

Afghanistan Casualties: Military Forces and Civilians

This report collects statistics from a variety of sources on casualties sustained during Operation Enduring Freedom (OEF), which began on October 7, 2001. OEF actions took place primarily in Afghanistan; however, OEF casualties also includes American casualties in Pakistan, Uzbekistan, Guantanamo Bay (Cuba), Djibouti, Eritrea, Ethiopia, Jordan, Kenya, Kyrgyzstan, the Philippines, Seychelles, Sudan, Tajikistan, Turkey, and Yemen.
Date: February 26, 2010
Creator: Chesser, Susan G.
Object Type: Report
System: The UNT Digital Library
Alternate Alpha Induced Reactions for NIF Radiochemistry (open access)

Alternate Alpha Induced Reactions for NIF Radiochemistry

Radiochemical analysis of NIF capsule residues has been identified as a potential diagnostic of NIF capsule performance. In particular, alpha-induced nuclear reactions that occur on tracer elements added to the NIF capsule have been shown through simulation to be a very sensitive diagnostic for mix. The short range of the alpha particles makes them representative of the hot spot where they are created through the fusion of deuterium and tritium. Reactions on elements doped into the innermost part of the capsule ablator would therefore be sensitive to material that had mixed into the hot spot. Radiochemical determinations of activated detector elements may perhaps be the only true measure of mix that occurs in a NIF capsule, particularly in cases when the capsule fails.
Date: February 26, 2010
Creator: Shaughnessy, D A; Moody, K J & Bernstein, L A
Object Type: Report
System: The UNT Digital Library
American War and Military Operations Casualties: Lists and Statistics (open access)

American War and Military Operations Casualties: Lists and Statistics

This report is written in response to numerous requests for war casualty statistics and lists of war dead. It provides tables, compiled by sources at the Department of Defense (DOD), indicating the number of casualties among American military personnel serving in principal wars and combat actions.
Date: February 26, 2010
Creator: Leland, Anne & Oboroceanu, Mari-Jana
Object Type: Report
System: The UNT Digital Library
Analytical Data Report of Grab Samples Collected From 200-ZP-1 Remedial Action Wells (open access)

Analytical Data Report of Grab Samples Collected From 200-ZP-1 Remedial Action Wells

This is an analytical data report prepared for CHPRC from grab samples received for 200-ZP-1 operable unit.
Date: February 26, 2010
Creator: Lindberg, Michael J.
Object Type: Report
System: The UNT Digital Library
Asian Carp and the Great Lakes Region (open access)

Asian Carp and the Great Lakes Region

This report is on Asian Carp and the Great Lakes Region.
Date: February 26, 2010
Creator: Buck, Eugene H.; Upton, Harold F. & Stern, Charles V.
Object Type: Report
System: The UNT Digital Library
Comprehensive Characterization of Voids and Microstructure in TATB-based Explosives from 10 nm to 1 cm: Effects of Temperature Cycling and Compressive Creep (open access)

Comprehensive Characterization of Voids and Microstructure in TATB-based Explosives from 10 nm to 1 cm: Effects of Temperature Cycling and Compressive Creep

This paper outlines the characterization of voids and Microstructure in TATB-based Explosives over several orders of magnitude, from sizes on the order of 10 nm to about 1 cm. This is accomplished using ultra small angle x-ray scattering to investigate voids from a few nm to a few microns, ultra small angle neutron scattering for voids from 100 nm to 10 microns, and x-ray computed microtomography to investigate microstructure from a few microns to a few centimeters. The void distributions of LX-17 are outlined, and the microstructure of LX-17 is presented. Temperature cycling and compressive creep cause drastically different damage to the microstructure. Temperature cycling leads to a volume expansion (ratchet growth) in TATB-based explosives, and x-ray scattering techniques that are sensitive to sizes up to a few microns indicated changes to the void volume distribution that had previously accounted for most, but not all of the change in density. This paper presents the microstructural damage larger than a few microns caused by ratchet growth. Temperature cycling leads to void creation in the binder poor regions associated with the interior portion of formulated prills. Conversely, compressive creep causes characteristically different changes to microstructure; fissures form at binder-rich prill boundaries prior …
Date: February 26, 2010
Creator: Willey, T. M.; Lauderbach, L.; Gagliardi, F.; Cunningham, B.; Lorenz, K. T.; Lee, J. I. et al.
Object Type: Article
System: The UNT Digital Library
Distribution of Small Business Ownership and Income by Individual Tax Rates and Selected Policy Issues (open access)

Distribution of Small Business Ownership and Income by Individual Tax Rates and Selected Policy Issues

This report examines how small business owners may be affected by tax increases by exploring what is known about the share of small business owners and of small business income that is subject to the top two marginal income tax rates.
Date: February 26, 2010
Creator: Guenther, Gary
Object Type: Report
System: The UNT Digital Library
The Effects of Degraded Digital Instrumentation and Control Systems on Human-system Interfaces and Operator Performance: HFE Review Guidance and Technical Basis (open access)

The Effects of Degraded Digital Instrumentation and Control Systems on Human-system Interfaces and Operator Performance: HFE Review Guidance and Technical Basis

New and advanced reactors will use integrated digital instrumentation and control (I&C) systems to support operators in their monitoring and control functions. Even though digital systems are typically highly reliable, their potential for degradation or failure could significantly affect operator performance and, consequently, impact plant safety. The U.S. Nuclear Regulatory Commission (NRC) supported this research project to investigate the effects of degraded I&C systems on human performance and plant operations. The objective was to develop human factors engineering (HFE) review guidance addressing the detection and management of degraded digital I&C conditions by plant operators. We reviewed pertinent standards and guidelines, empirical studies, and plant operating experience. In addition, we conducted an evaluation of the potential effects of selected failure modes of the digital feedwater system on human-system interfaces (HSIs) and operator performance. The results indicated that I&C degradations are prevalent in plants employing digital systems and the overall effects on plant behavior can be significant, such as causing a reactor trip or causing equipment to operate unexpectedly. I&C degradations can impact the HSIs used by operators to monitor and control the plant. For example, sensor degradations can make displays difficult to interpret and can sometimes mislead operators by making it …
Date: February 26, 2010
Creator: O'Hara, J. M. & W. Gunther, G. Martinez-Guridi
Object Type: Report
System: The UNT Digital Library
Federal Register, Volume 75, Number 38, February 26, 2010, Pages 8795-9084 (open access)

Federal Register, Volume 75, Number 38, February 26, 2010, Pages 8795-9084

Daily publication of the U.S. Office of the Federal Register contains rules and regulations, proposed legislation and rule changes, and other notices, including "Presidential proclamations and Executive Orders, Federal agency documents having general applicability and legal effect, documents required to be published by act of Congress, and other Federal agency documents of public interest" (p. ii). Table of Contents starts on page iii.
Date: February 26, 2010
Creator: United States. Office of the Federal Register.
Object Type: Journal/Magazine/Newsletter
System: The UNT Digital Library
Illegal Drug Trade in Africa: Trends and U.S. Policy (open access)

Illegal Drug Trade in Africa: Trends and U.S. Policy

This report provides an introduction to the rising drug trafficking threat and discusses the drug trafficking trends in Africa and the U.S. policy.
Date: February 26, 2010
Creator: Wyler, Liana Sun & Cook, Nicolas
Object Type: Report
System: The UNT Digital Library
Intelligence Issues for Congress (open access)

Intelligence Issues for Congress

This report discusses the efforts currently underway to improve coordination and encourage better analysis amongst the various agencies within the U.S. Intelligence Community, especially with regard to the ongoing and prominent issue of international terrorism. In particular, this report addresses the false intelligence regarding Iraqi weapons of mass destruction and the current efforts in Iraq and Iran in general.
Date: February 26, 2010
Creator: Best, Richard A., Jr.
Object Type: Report
System: The UNT Digital Library
Navy CG(X) Cruiser Program: Background for Congress (open access)

Navy CG(X) Cruiser Program: Background for Congress

The Navy's FY2011 budget proposes canceling the CG(X) program as unaffordable and instead building an improved version of the Arleigh Burke (DDG-51) class Aegis destroyer called the Flight III version. This report provides background information on the CG(X) program as it existed prior to its proposed cancellation.
Date: February 26, 2010
Creator: O'Rourke, Ronald
Object Type: Report
System: The UNT Digital Library
Navy DDG-51 and DDG-1000 Destroyer Programs: Background and Issues for Congress (open access)

Navy DDG-51 and DDG-1000 Destroyer Programs: Background and Issues for Congress

This report discusses issues Congress faces regarding the Navy's proposed FY2011 budget, particularly as relating to destroyer procurement plans and programs.
Date: February 26, 2010
Creator: O'Rourke, Ronald
Object Type: Report
System: The UNT Digital Library
Navy Virginia (SSN-774) Class Attack Submarine Procurement: Background and Issues for Congress (open access)

Navy Virginia (SSN-774) Class Attack Submarine Procurement: Background and Issues for Congress

The Navy has been procuring Virginia (SSN-774) class nuclear-powered attack submarines (SSNs) at a rate of one per year for the past several years, and a total of 12 boats have been procured through FY2010. The Navy's proposed FY2011 budget increases the procurement rate to two boats per year. This report discusses the Navy's proposed FY2011 budget, which requests $3,441.5 million in procurement funding to complete the procurement cost of the 13th and 14th Virginia-class boats.
Date: February 26, 2010
Creator: O'Rourke, Ronald
Object Type: Report
System: The UNT Digital Library