Load As A Reliability Resource in the Restructured Electricity Market (open access)

Load As A Reliability Resource in the Restructured Electricity Market

Recent electricity price spikes are painful reminders of the value that meaningful demand-side responses could bring to the restructuring US electricity system. Review of the aggregate offers made by suppliers confirms that even a modest increase in demand elasticity could dramatically reduce these extremes in price volatility. There is a strong need for dramatically increased customer participation in these markets to enhance system reliability and reduce price volatility. Indeed, allowing customers to manage their loads in response to system conditions might be thought of as the ultimate reliability resource. Most would agree that meaningful demand-side responses to price are the hallmark of a well-functioning competitive market [1]. Yet, in today's markets for electricity, little or no such response is evident. The reason is simple: customers currently do not experience directly the time-varying costs of their consumption decisions. Consequently, they have no incentive to modify these decisions in ways that might enhance system reliability or improve the efficiency of the markets in which electricity is traded. Increased customer participation is a necessary step in the evolution toward more efficient markets for electricity and ancillary services. This scoping report provides a three-part assessment of the current status of efforts to enhance the …
Date: June 10, 2002
Creator: Kueck, J. D.
Object Type: Report
System: The UNT Digital Library
Understanding the impact of upscaling THM processes on performance assessment (open access)

Understanding the impact of upscaling THM processes on performance assessment

The major objective of Benchmark Test 2 (BMT2) is to quantitatively examine the reliability of estimates of repository host rock performance, using large-scale performance assessment (PA) models that are developed by upscaling small-scale parameters and processes. These small-scale properties and processes can be investigated based on either discrete-fracture-network (DFN) models or heterogeneous-porous-medium (HPM) models. While most research teams use DFN, we employ fractal-based HPM for upscaling purposes. Comparison of results based on fundamentally different approaches is useful for evaluating and bounding the uncertainties in estimating repository host rock performance. HPM has both advantages and limitations when compared with DFN. DFM is conceptually more appealing because it explicitly describes fractures and the flow and transport processes that occur within them. However, HPM is more consistent with approaches used to derive field measurements of hydraulic properties (such as permeability). These properties are generally determined based on assumptions related to the continuum approach. HPM is also more straightforward in describing spatial-correlation structures of measured hydraulic properties. For example, potential flow features in the Borrowdale Volcanic Group (BVG) were found to show marked spatial clustering (Nirex, 1997), which is expected to result in a long range correlation in measured permeability distributions. This important behavior …
Date: June 10, 2002
Creator: Liu, H. H.; Zhou, Q.; Rutqvist, J. & Bodvarsson, G. S.
Object Type: Report
System: The UNT Digital Library
Effects of the narrow band gap on the properties of InN (open access)

Effects of the narrow band gap on the properties of InN

None
Date: September 10, 2002
Creator: Wu, J.; Walukiewicz, W.; Shan, W.; Yu, K. M.; Ager, J. W., III; Haller, E. E. et al.
Object Type: Article
System: The UNT Digital Library
Design of 2.4 GHz CMOS Direct Conversion LNA and Mixer Combination for Wirless Data-Link Transceiver (open access)

Design of 2.4 GHz CMOS Direct Conversion LNA and Mixer Combination for Wirless Data-Link Transceiver

Three LNA and mixer combinations in 0.6{micro}m and 0.4{micro}m standard CMOS processes for direct-conversion receiver of 2.4GHz ISM band short-range wireless data-link applications are described in this paper. Taking low power dissipation as first consideration, these designs, employing differential common-source LNA and double balanced mixer architectures, achieve total conversion gain as high as 42.4dB, DSB noise figure as low as 9.5dB, output-referred IP3 as high as of 21.3dBm at about 4mA DC current consumption. This proves it is possible to apply standard CMOS process to implement receiver front-end with low power dissipation for this kind of application, but gain changeable LNA is needed to combat the dominant flicker noise of the mixer in order to achieve acceptable sensitivity and dynamic range at the same time.
Date: April 10, 2002
Creator: Zhao, Desong & O'Connor, Paul
Object Type: Report
System: The UNT Digital Library
Authorization policy in a PKI environment (open access)

Authorization policy in a PKI environment

The major emphasis of Public Key Infrastructure has been to provide a cryptographically secure means of authenticating identities. While there are a number of proposed standards for authorization structures and protocols based on X.509 or other key-based identities, none have been widely adopted. As part of an effort to use X.509 identities to provide authorization in highly distributed environments, we have developed and deployed an authorization service based on X.509 identified users and access policy contained in certificates signed by X.509 identified stakeholders. The major goal of this system, called Akenti, is to produce a usable authorization system for an environment consisting of distributed resources used by geographically and administratively distributed users.
Date: April 10, 2002
Creator: Thompson, Mary R.; Mudumbai, Srilekha S.; Essiari, Abdelilah & Chin, Willie
Object Type: Article
System: The UNT Digital Library
Production of Simulated Sludge Batch 2 Melter Feed Containing Frit 320 in the 1/240th Glass Feed Preparation System (open access)

Production of Simulated Sludge Batch 2 Melter Feed Containing Frit 320 in the 1/240th Glass Feed Preparation System

This report was prepared to fulfill a deliverable for HLW/DWPF/TTR-2002-00008, Rev. 0, ''Glass Feed Preparation System Runs for Minimelter Feed Preparation with Frit 320, 1/10/2002. Approximately 50 gallons of Sludge Batch 2 simulated melter feed containing Frit 320 were produced from 58 gallons of a simulated Sludge Batch 2 slurry.
Date: July 10, 2002
Creator: Koopman, D. C.
Object Type: Report
System: The UNT Digital Library
Measurement of Simulated Waste Glass Viscosity (open access)

Measurement of Simulated Waste Glass Viscosity

A new high-temperature glass viscometer instrument was established and evaluated using a simulated waste glass in a comparative test with eight other laboratories and viscometers. The unit has distinct advantages in physical size, the amount of glass required for testing, and the simplicity of operation. These advantages can be important for work with radioactive materials. Results from the comparison indicate excellent accuracy and repeatability.
Date: July 10, 2002
Creator: Schumacher, R. F.
Object Type: Book
System: The UNT Digital Library
Final Report - Ferrographic Tracking of Bacterial Transport (open access)

Final Report - Ferrographic Tracking of Bacterial Transport

The work performed during the past three years has been extremely productive. Ferrographic capture was utilized in analysis of several thousand field samples collected from arrays of multilevel samplers during three intensive field campaigns conducted at two shallow sandy aquifer sites in Oyster, VA. This work has shown resulted in three important conclusions: (1) Ferrographic capture provides unparalleled low quantitation limits for bacterial cell enumeration (Johnson et al., 2000). (2) The high-resolution analyses provided by ferrographic capture allowed observation of increased bacterial removal rates (from groundwater) that corresponded to increased populations of protozoa in the groundwater (Zhang et al., 2001). This novel data allowed determination of bacterial predation rates by protists in the field, a consideration that will be important for successful bioaugmentation strategies. (3) The high-resolution analyses provided by ferrographic capture allowed observation of detachment of indigenous cells in response to breakthrough of injected cells in groundwater (Johnson et al., 2001). The implication of this unique observation is that bacterial transport, specifically bacterial attachment and detachment, may be much more dynamic than has been indicated by short-term laboratory and field studies. Dynamic attachment and detachment of bacteria in groundwater may lead to greatly increased transport distances over long terms …
Date: October 10, 2002
Creator: Johnson, William P.
Object Type: Report
System: The UNT Digital Library
Design Analysis for a Scaled Erosion Test (open access)

Design Analysis for a Scaled Erosion Test

In support of a slurry wear evaluation in the pretreatment filtration and evaporation systems of RPP-WTP, Engineering Modeling and Simulation Group (EMSG) has developed the computational models to help guide component design and scaling decisions and to assist in the full-scale analyses. This report deals with the filtration system. In this project, computational fluid dynamics (CFD) methods were applied to ensure that the test facility design would capture the erosion phenomena expected in the full-scale cross-flow ultrafiltration facility. The literature survey was initially performed to identify the principal mechanisms of erosion for a solids laden fluid.
Date: April 10, 2002
Creator: Lee, Si Young
Object Type: Report
System: The UNT Digital Library
Analysis of Disposal of Lead in the E-Area Low-Level Waste Facility (open access)

Analysis of Disposal of Lead in the E-Area Low-Level Waste Facility

Savannah River Site has received approval from SCDHEC for disposal of radioactively contaminated equipment with lead shielding or counterweights. The objective of this analysis was to document the technical basis for the administrative limit of 100,000 pounds approved by SCDHEC under alternative disposal strategies.
Date: May 10, 2002
Creator: Wilhite, E.L.
Object Type: Report
System: The UNT Digital Library
Development of Probabilistic Uncertainty Analysis Methodology for SRS Performance Assessments Maintenance Plan Activities (open access)

Development of Probabilistic Uncertainty Analysis Methodology for SRS Performance Assessments Maintenance Plan Activities

An initial uncertainty analysis of the Performance Assessment (PA) model of the Savannah River Site (SRS) trench disposal unit was conducted. Selected input data values were varied for both flow and transport analyses to generate input sets called realizations. Outputs of fluxes to the water table and well concentrations were compared to results from the PA. This stage of the uncertainty analysis served as a prototype for future work. The focus was to lay the foundation for a more comprehensive analysis, generate a limited set of output results, and learn about the process and potential problems.
Date: July 10, 2002
Creator: Cook, J. R.
Object Type: Report
System: The UNT Digital Library
Water balance in fuel cells systems. (open access)

Water balance in fuel cells systems.

Fuel cell systems are attractive for their high efficiency (i.e., electric power generated per weight/volume of fuel,) and lower emissions. These systems are being developed for applications that include transportation (propulsion and auxiliary), remote stationary, and portable. Where these systems use on-board fuel processing of available fuels, the fuel processor requires high-purity water. For utility applications, this water may be available on-site, but for most applications, the process water must be recovered from the fuel cell system exhaust gas. For such applications, it is critically important that the fuel cell system be a net water-producing device. A variety of environmental conditions (e.g., ambient temperature, pressure), fuel cell system design, and operating conditions determine whether the fuel cell system is water-producing or water-consuming. This paper will review and discuss the conditions that determine the net-water balance of a generic fuel cell system and identify some options that will help meet the water needs of the fuel processor.
Date: January 10, 2002
Creator: Kopasz, J.; Ahmed, S.; Kumar, R. & Krumpelt, M.
Object Type: Article
System: The UNT Digital Library
Practical Use of Rotordynamic Analysis to Correct a Vertical Long Shaft Pump's Whirl Problem (open access)

Practical Use of Rotordynamic Analysis to Correct a Vertical Long Shaft Pump's Whirl Problem

The use of long shaft vertical pumps is common practice in the nuclear waste processing industry. Unfortunately, when such pumps employ plain cylindrical journal bearings, they tend to suffer from rotordynamic instability problems due to the inherent lightly-loaded condition that the vertical orientation places on the bearings. This paper describes a case study in which the authors utilized rotordynamic analysis and experimental vibration analysis to diagnose such a problem and designed replacement tilting-pad bearings to solve the problem.
Date: May 10, 2002
Creator: Leishear, R. A.
Object Type: Article
System: The UNT Digital Library
MULTI - QUARK HADRONS : PRODUCTION OF S = - 2 SYSTEMS. (open access)

MULTI - QUARK HADRONS : PRODUCTION OF S = - 2 SYSTEMS.

The general character of 4-quark (mesonic) and strange 6-quark (baryonic) quark systems is very briefly reviewed a la Jaffe, i.e. in the MIT bag, and so far still possibly viable candidates are indicated. The concentration is on the latter (S = -2) systems, with some attention given to more likely to be discoverable light, doubly-strange nuclei. The two modes for generating doubly strange, generally double-{Lambda} nuclear systems, are considered and related to each other. Traditionally, one employs the (K{sup -},K{sup +}) reaction on a relatively light target and hopes to retain two units of strangeness on a single final state fragment. Alternatively, heavy ion reactions can be used to produce {Lambda}-hyperons copiously and one seeks to observe coalescence of two of these particles into the lightest S=-2 nucleus, the H-dibaryon. The complications arising from the presence of a repulsive core in the baryon-baryon interaction on the production of the H are discussed. Also considered is the possible presence in the data from the AGS experiment E906, of slightly heavier S=-2 nuclei, in particular in the system {sub {lambda}{lambda}}{sup 4}H.
Date: June 10, 2002
Creator: KAHANA,D.E. & KAHANA,S.H.
Object Type: Article
System: The UNT Digital Library
Quantum cosmology based on discrete Feynman paths (open access)

Quantum cosmology based on discrete Feynman paths

Although the rules for interpreting local quantum theory imply discretization of process, Lorentz covariance is usually regarded as precluding time quantization. Nevertheless a time-discretized quantum representation of redshifting spatially-homogeneous universe may be based on discrete-step Feynman paths carrying causal Lorentz-invariant action--paths that not only propagate the wave function but provide a phenomenologically-promising elementary-particle Hilbert-space basis. In a model under development, local path steps are at Planck scale while, at a much larger ''wave-function scale'', global steps separate successive wave-functions. Wave-function spacetime is but a tiny fraction of path spacetime. Electromagnetic and gravitational actions are ''at a distance'' in Wheeler-Feynman sense while strong (color) and weak (isospin) actions, as well as action of particle motion, are ''local'' in a sense paralleling the action of local field theory. ''Nonmaterial'' path segments and ''trivial events'' collaborate to define energy and gravity. Photons coupled to conserved electric charge enjoy privileged model status among elementary fermions and vector bosons. Although real path parameters provide no immediate meaning for ''measurement'', the phase of the complex wave function allows significance for ''information'' accumulated through ''gentle'' electromagnetic events involving charged matter and ''soft'' photons. Through its soft-photon content the wave function is an ''information reservoir''.
Date: October 10, 2002
Creator: Chew, Geoffrey F.
Object Type: Article
System: The UNT Digital Library
Flavor physics: The flavor physics (P2) working group (open access)

Flavor physics: The flavor physics (P2) working group

Flavor physics has recently made striking advances. The Snowmass Flavor Physics Working Group has attempted to identify the important open questions in this field, and to describe the diverse future program that would address them.
Date: December 10, 2002
Creator: Artuso, Maria; Gavela, Belen; Kayser, Boris; McGrew, Clark; Rankin, Patricia & Zimmerman, Eric D.
Object Type: Article
System: The UNT Digital Library
Temperature and frequency effects in a high-performance superconducting bearing. (open access)

Temperature and frequency effects in a high-performance superconducting bearing.

A high-temperature superconducting (HTS) bearing was fabricated and tested by itself and as a component in a 1-kWh and a 10-kWh flywheel energy system (FES). The rotational losses of the HTS bearing as a function of rotational rate and HTS temperature were determined. The 1-kWh FES was tested with a motor/generator and with an eddy current clutch to determine the motor/generator losses.
Date: September 10, 2002
Creator: Day, A. C.; Hull, J. R.; Strasik, M.; Johnson, P. E.; McCrary, K. E.; Edwards, J. et al.
Object Type: Article
System: The UNT Digital Library
Amplitude and TIme Measurement ASIC With Analog Derandomization (open access)

Amplitude and TIme Measurement ASIC With Analog Derandomization

We describe a new ASIC for accurate and efficient processing of high-rate pulse signals from highly segmented detectors. In contrast to conventional approaches, this circuit affords a dramatic reduction in data volume through the use of analog techniques (precision peak detectors and time-to-amplitude converters) together with fast arbitration and sequencing logic to concentrate the data before digitization. In operation the circuit functions like a data-driven analog first-in, first-out (FIFO) memory between the preamplifiers and the ADC. Peak amplitudes of pulses arriving at any one of the 32 inputs are sampled, stored, and queued for readout and digitization through a single output port. Hit timing, pulse risetime, and channel address are also available at the output. Prototype chips have been fabricated in 0.35 micron CMOS and tested. First results indicate proper functionality for pulses down to 30 ns peaking time and input rates up to 1.6 MHz/channel. Amplitude accuracy of the peak detect and hold circuit is 0.3% (absolute). TAC accuracy is within 0.3% of full scale. Power consumption is less than 2 mW/channel. Compared with conventional techniques such as track-and-hold and analog memory, this new ASIC will enable efficient pulse height measurement at 20 to 300 times higher rates.
Date: November 10, 2002
Creator: O'Connor, P.; De Geronimo, G. & Kandasamy, A.
Object Type: Article
System: The UNT Digital Library
CONTROL SYSTEM ANALYSIS FOR THE PERTURBED LINEAR ACCELERATOR RF SYSTEM (open access)

CONTROL SYSTEM ANALYSIS FOR THE PERTURBED LINEAR ACCELERATOR RF SYSTEM

This paper addresses the modeling problem of the linear accelerator RF system in SNS. Klystrons are modeled as linear parameter varying systems. The effect of the high voltage power supply ripple on the klystron output voltage and the output phase is modeled as an additive disturbance. The cavity is modeled as a linear system and the beam current is modeled as the exogenous disturbance. The output uncertainty of the low level RF system which results from the uncertainties in the RF components and cabling is modeled as multiplicative uncertainty. Also, the feedback loop uncertainty and digital signal processing signal conditioning subsystem uncertainties are lumped together and are modeled as multiplicative uncertainty. Finally, the time delays in the loop are modeled as a lumped time delay. For the perturbed open loop system, the closed loop system performance, and stability are analyzed with the PI feedback controller.
Date: April 10, 2002
Creator: KWON, SUNG-IL & REGAN, AMY H.
Object Type: Report
System: The UNT Digital Library
RECENT SNO RESULTS. (open access)

RECENT SNO RESULTS.

Solar Neutrinos from the decay of {sup 8}B have been detected at the Sudbury Neutrino Observatory (SNO) by charged current (CC) and neutral current (NC) interactions on deuterium and elastic scattering (ES) of electrons. The SNO data indicate that with the assumption of undistorted {sup 8}B shape, the flux for v{sub e} is {phi}{sub e} = 1.76{sub -0.05}{sup +0.05}(stat.){sub -0.09}{sup +0.09}(syst.) x 10{sup 6} cm{sup -2} s{sup -1} for a kinetic energy threshold of 5 MeV. The non-v{sub e} flux is {phi}{sub {mu}{tau}} = 3.41{sub -0.45}{sup +0.45}(stat.){sub -0.45}{sup +0.48}(syst.) x 10{sup 6} cm{sup -2}s{sup -1}. This provides strong evidence for solar v{sub e} flavor transformation. The day and night solar neutrino energy spectra and rates have also been measured. For CC events, the v{sub e} asymmetry is 14.0% {+-} 6.3%{sub -1.4}{sup +1.5}%. By additionally constraining the total (NC) flux of active neutrinos to have no asymmetry, the v{sub e} asymmetry becomes 7.0% {+-} 4.9%{sub -1.2}{sup +1.3}%. A global solar neutrino analysis strongly favors the Large Mixing Angle (LMA) solution in a two-flavor neutrino oscillation model.
Date: December 10, 2002
Creator: Yeh, Minfang
Object Type: Article
System: The UNT Digital Library
Making automatic differentiation truly automatic : coupling PETSc with ADIC. (open access)

Making automatic differentiation truly automatic : coupling PETSc with ADIC.

Despite its name, automatic differentiation (AD) is often far from an automatic process. often one must specify independent and dependent variables, indicate the derivative quantities to be computed, and perhaps even provide information about the structure of the Jacobians or Hessians being computed. However, when AD is used in conjunction with a toolkit with well-defined interfaces, many of these issues do not arise. They describe recent research into coupling the ADIC automatic differentiation tool with PETSc, a toolkit for the parallel numerical solution of PDEs. This research leverages the interfaces and objects of PETSc to make the AD process very nearly transparent.
Date: January 10, 2002
Creator: Hovland, P.; Norris, B. & Smith, B.
Object Type: Article
System: The UNT Digital Library
Texas Register, Volume 27, Number 19, Pages 3851-4226, May 10, 2002 (open access)

Texas Register, Volume 27, Number 19, Pages 3851-4226, May 10, 2002

A weekly publication, the Texas Register serves as the journal of state agency rulemaking for Texas. Information published in the Texas Register includes proposed, adopted, withdrawn and emergency rule actions, notices of state agency review of agency rules, governor's appointments, attorney general opinions, and miscellaneous documents such as requests for proposals. After adoption, these rulemaking actions are codified into the Texas Administrative Code.
Date: May 10, 2002
Creator: Texas. Secretary of State.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Information Technology: Inconsistent Software Acquisition Processes at the Defense Logistics Agency Increase Project Risks (open access)

Information Technology: Inconsistent Software Acquisition Processes at the Defense Logistics Agency Increase Project Risks

A letter report issued by the General Accounting Office with an abstract that begins "The Defense Logistics Agency (DLA) plays a critical role in supporting America's military forces worldwide. DLA relies on software-intensive systems to support its work. An important determinant of the quality of software-intensive systems, and thus DLA's mission performance, is the quality of the processes used to acquire these systems. DLA lacks mature software acquisition processes across the agency, as seen in the wide disparity in the rigor and discipline of processes between the two systems GAO evaluated. DLA also lacks a software process improvement program to effectively strengthen its corporate software acquisition processes."
Date: January 10, 2002
Creator: United States. General Accounting Office.
Object Type: Report
System: The UNT Digital Library
The Origination Clause of the U.S. Constitution: Interpretation and Enforcement (open access)

The Origination Clause of the U.S. Constitution: Interpretation and Enforcement

This report analyzes congressional and court precedents regarding bills under Article I, Section 7, clause 1 of the U.S. Constitution (known as the Origination Clause). It also describes the various ways in which the Origination Clause has been enforced and looks at the application of the Clause to other types of legislation.
Date: May 10, 2002
Creator: Saturno, James V.
Object Type: Report
System: The UNT Digital Library