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A 10 Hz Grazing Incidence pumped Ni-like Mo laser at 18.9 nm with 150 mJ pump energy (open access)

A 10 Hz Grazing Incidence pumped Ni-like Mo laser at 18.9 nm with 150 mJ pump energy

The first demonstration of the grazing incidence pumping (GRIP) scheme for laser-driven x-ray lasers (XRLs) is described utilizing 2-pulse pumping. A long pulse is incident normal to the target to produce a plasma with a particular density profile. Then a short pulse is incident at a grazing angle, chosen to optimally couple the short pulse laser energy into the specific density region where the inversion process will occur. The short pulse is simultaneously absorbed and refracted at a maximum electron density specified by the chosen pump angle then turns back into the gain region. The increased path length gives improved absorption allowing a reduction in the drive energy required for lasing. A Ni-like Mo XRL at 18.9 nm has been demonstrated with only 150 mJ total pump energy and a repetition rate of 10 Hz. We report high gains of 60 cm{sup -1} and the achievement of gain saturation for targets of 4 mm length.
Date: September 30, 2004
Creator: Keenan, R.; Dunn, J.; Patel, P. K.; Price, D. F.; Smith, R. F. & Shlyaptsev, V. N.
Object Type: Article
System: The UNT Digital Library
A 10 kHz Short-Stroke Rotary Fast Tool Servo (open access)

A 10 kHz Short-Stroke Rotary Fast Tool Servo

None
Date: August 30, 2004
Creator: Montesanti, R C & Trumper, D L
Object Type: Article
System: The UNT Digital Library
Ab Initio No-Core Shell Model Calculations Using Realistic Two- and Three-Body Interactions (open access)

Ab Initio No-Core Shell Model Calculations Using Realistic Two- and Three-Body Interactions

There has been significant progress in the ab initio approaches to the structure of light nuclei. One such method is the ab initio no-core shell model (NCSM). Starting from realistic two- and three-nucleon interactions this method can predict low-lying levels in p-shell nuclei. In this contribution, we present a brief overview of the NCSM with examples of recent applications. We highlight our study of the parity inversion in {sup 11}Be, for which calculations were performed in basis spaces up to 9{Dirac_h}{Omega} (dimensions reaching 7 x 10{sup 8}). We also present our latest results for the p-shell nuclei using the Tucson-Melbourne TM three-nucleon interaction with several proposed parameter sets.
Date: November 30, 2004
Creator: Navratil, P; Ormand, W E; Forssen, C & Caurier, E
Object Type: Article
System: The UNT Digital Library
Abandoned Mine Land Fund Reauthorization: Selected Issues (open access)

Abandoned Mine Land Fund Reauthorization: Selected Issues

This report provides a summary of the structure of the Abandon Mine Land (AML) program, distribution of funds, and discusses major proposals considered in the 108th Congress.
Date: April 30, 2004
Creator: Bamberger, Robert L.
Object Type: Report
System: The UNT Digital Library
Adaptive Importance Sampling Monte Carlo Simulation of Rare Transition Events (open access)

Adaptive Importance Sampling Monte Carlo Simulation of Rare Transition Events

We present an adaptive importance sampling method for quantifying the statistics of rare-event processes in atomistic simulations. The approach is based on an explicit evaluation of the probability that a sequence of states (or path) initiating in a state A leads to a reactive transition event to final state B. The importance sampling method seeks to bias the sampling of system trajectories such that those that contribute significantly, i.e. those that characterize reactive transitions, are generated more frequently. This is accomplished by means of an importance function, which modifies the transition probabilities among the microstates that comprise a path. For each problem there exists an optimal importance function, which biases that path sampling in such a manner that each path initiating in A leads to a successful event. The fact that the optimal function obeys a variational principle, then leads to an adaptive method in which a trial function form containing a set of adjustable parameters is chosen. The parameters are then adjusted so as to bring the trial function as close as possible to the optimal importance function. We demonstrate the method in two model problems.
Date: August 30, 2004
Creator: de Koning, M; Cai, W; Sadigh, B; Oppelstrup, T; Kalos, M H & Bulatov, V V
Object Type: Article
System: The UNT Digital Library
Additional Posthearing Questions Related to Proposed Department of Homeland Security (DHS) Human Capital Regulations (open access)

Additional Posthearing Questions Related to Proposed Department of Homeland Security (DHS) Human Capital Regulations

Correspondence issued by the General Accounting Office with an abstract that begins "On February 25, 2004, Congress heard testimony at a hearing entitled "The Key to Homeland Security: The New Human Resources System." This report responds to additional questions posed by Senator Akaka and Senator Lautenberg."
Date: April 30, 2004
Creator: United States. General Accounting Office.
Object Type: Text
System: The UNT Digital Library
Advanced Cuttings Transport Study: Final Technical Report (open access)

Advanced Cuttings Transport Study: Final Technical Report

The Advanced Cuttings Transport Study (ACTS) was a 5-year JIP project undertaken at the University of Tulsa (TU). The project was sponsored by the U.S. Department of Energy (DOE) and JIP member companies. The objectives of the project were: (1) to develop and construct a new research facility that would allow three-phase (gas, liquid and cuttings) flow experiments under ambient and EPET (elevated pressure and temperature) conditions, and at different angle of inclinations and drill pipe rotation speeds; (2) to conduct experiments and develop a data base for the industry and academia; and (3) to develop mechanistic models for optimization of drilling hydraulics and cuttings transport. This project consisted of research studies, flow loop construction and instrumentation development. Following a one-year period for basic flow loop construction, a proposal was submitted by TU to the DOE for a five-year project that was organized in such a manner as to provide a logical progression of research experiments as well as additions to the basic flow loop. The flow loop additions and improvements included: (1) elevated temperature capability; (2) two-phase (gas and liquid, foam etc.) capability; (3) cuttings injection and removal system; (4) drill pipe rotation system; and (5) drilling section elevation …
Date: September 30, 2004
Creator: Miska, Stefan; Reed, Troy & Kuru, Ergun
Object Type: Report
System: The UNT Digital Library
An Advanced Fracture Characterization and Well Path Navigation System for Effective Re-Development and Enhancement of Ultimate Recovery From the Complex Monterey Reservoir of South Ellwood Field, Offshore California, Quarterly Report: March - June 2004 (open access)

An Advanced Fracture Characterization and Well Path Navigation System for Effective Re-Development and Enhancement of Ultimate Recovery From the Complex Monterey Reservoir of South Ellwood Field, Offshore California, Quarterly Report: March - June 2004

Venoco Inc, intends to re-develop the Monterey Formation, a Class III basin reservoir, at South Ellwood Field, Offshore Santa Barbara, California. Well productivity in this field varies significantly. Cumulative Monterey production for individual wells has ranged from 260 STB to 8,700,000 STB. Productivity is primarily affected by how well the well path connects with the local fracture system and the degree of aquifer support. Cumulative oil recovery to date is a small percentage of the original oil in place. To embark upon successful re-development and to optimize reservoir management, Venoco intends to investigate, map and characterize field fracture patterns and the reservoir conduit system. State of the art borehole imaging technologies including FMI, dipole sonic and cross-well seismic, interference tests and production logs will be employed to characterize fractures and micro faults. These data along with the existing database will be used for construction of a novel geologic model of the fracture network. Development of an innovative fracture network reservoir simulator is proposed to monitor and manage the aquifer's role in pressure maintenance and water production. The new fracture simulation model will be used for both planning optimal paths for new wells and improving ultimate recovery. In the second phase …
Date: July 30, 2004
Creator: Horner, Steve
Object Type: Report
System: The UNT Digital Library
Advanced Hot Section Materials and Coatings Test Rig (open access)

Advanced Hot Section Materials and Coatings Test Rig

The Hyperbaric Advanced Hot Section Materials & Coating Test Rig program provides design and implementation of a laboratory rig capable of simulating the hot gas path conditions of coal-gas fired industrial gas turbine engines. The principal activities during this reporting period were the continuation of test section detail design and developing specifications for auxiliary systems and facilities.
Date: October 30, 2004
Creator: Davies, Dan
Object Type: Report
System: The UNT Digital Library
ADVANCED HOT SECTION MATERIALS AND COATINGS TEST RIG (open access)

ADVANCED HOT SECTION MATERIALS AND COATINGS TEST RIG

The Hyperbaric Advanced Hot Section Materials & Coating Test Rig program provides design and implementation of a laboratory rig capable of simulating the hot gas path conditions of coal-gas fired industrial gas turbine engines. The principal activity during this reporting period were the evaluation of syngas combustor concepts, the evaluation of test section concepts and the selection of the preferred rig configuration.
Date: April 30, 2004
Creator: Reome, Scott & Davies, Dan
Object Type: Report
System: The UNT Digital Library
Advanced Hydrogen Transport Membranes for Vision 21 Fossil Fuel Plants (open access)

Advanced Hydrogen Transport Membranes for Vision 21 Fossil Fuel Plants

The objective of this project is to develop an environmentally benign, inexpensive, and efficient method for separating hydrogen from gas mixtures produced during industrial processes, such as coal gasification. Currently, this project is focusing on four basic categories of dense membranes: (1) mixed conducting ceramic/ceramic composites, (2) mixed conducting ceramic/metal (cermet) composites, (3) cermets with hydrogen permeable metals, and (4) layered composites with hydrogen permeable alloys. The primary technical challenge in achieving the goals of this project will be to optimize membrane composition to enable practical hydrogen separation rates and chemical stability. Other key aspects of this developing technology include catalysis, ceramic processing methods, and separation unit design operating under high pressure. To achieve these technical goals, Eltron Research Inc. has organized a consortium consisting of CoorsTek, Sued Chemie, Inc. (SCI), Argonne National Laboratory (ANL), and NORAM. Hydrogen permeation rates in excess of 50 mL {center_dot} min{sup -1} {center_dot} cm{sup 2} at {approx}440 C were routinely achieved under less than optimal experimental conditions using a range of membrane compositions. Factors that limit the maximum permeation attainable were determined to be mass transport resistance of H{sub 2} to and from the membrane surface, as well as surface contamination. Mass transport resistance …
Date: January 30, 2004
Creator: Roark, Shane E.; Sammells, Anthony F.; Mackay, Richard; Morrison, Scott R.; Rolfe, Sara L.; Balachandran, U. et al.
Object Type: Report
System: The UNT Digital Library
Advanced, Low/Zero Emission Boiler Design and Operation (open access)

Advanced, Low/Zero Emission Boiler Design and Operation

This document reviews the work performed during the quarter April-June 2004. Task 1 (Site Preparation) had been completed 2003, along with three weeks of oxycombustion tests in Task 2 (experimental test performance) of the project. In current reporting period, the experimental testing has been completed: one additional week of tests has been performed to finalize the optimization of the combustion characteristics in O{sub 2}/CO{sub 2} environment ; two more days of testing were dedicated to mercury sampling in air-fired or O{sub 2}-fired conditions, and to characterization of heat transfer in O{sub 2} conditions vs. to air-blown conditions. Task 3 (Techno-Economic Study) has also been completed in current quarter: 250MWe, 500MWe and 1000MWe oxygen-fired PC unit have been simulated and quoted, and their performance and cost have been compared to same-capacity air-fired pulverized coal (PC) unit and IGCC. New and retrofit cases have been evaluated. The comparison has been completed in terms of capital cost, operating cost, cost of electricity and cost of CO{sub 2} avoided. The scope of task 4 (Conceptual Boiler Design) had been modified as per DOE request in previous quarter. Engineering calculations are currently in progress. Next steps include detail review of the experimental data collected during …
Date: June 30, 2004
Creator: Chatel-Pelage, Fabienne & Varagani, Rajani
Object Type: Report
System: The UNT Digital Library
Advanced Monitoring systems initiative (open access)

Advanced Monitoring systems initiative

The Advanced Monitoring Systems Initiative (AMSI) actively searches for promising technologies and aggressively moves them from the research bench into DOE/NNSA end-user applications. There is a large unfulfilled need for an active element that reaches out to identify and recruit emerging sensor technologies into the test and evaluation function. Sensor research is ubiquitous, with the seeds of many novel concepts originating in the university systems, but at present these novel concepts do not move quickly and efficiently into real test environments. AMSI is a widely recognized, self-sustaining ''business'' accelerating the selection, development, testing, evaluation, and deployment of advanced monitoring systems and components.
Date: September 30, 2004
Creator: Venedam, R. J.; Hohman, E. O.; Lohrstorfer, C. F.; Weeks, S. J.; Jones, J. B. & Haas, W. J.
Object Type: Article
System: The UNT Digital Library
ADVANCED MONITORING TO IMPROVE COMBUSTION TURBINE/COMBINED CYCLE CT/(CC) RELIABILITY, AVAILABILITY AND MAINTAINABILITY (RAM) (open access)

ADVANCED MONITORING TO IMPROVE COMBUSTION TURBINE/COMBINED CYCLE CT/(CC) RELIABILITY, AVAILABILITY AND MAINTAINABILITY (RAM)

Power generators are concerned with the maintenance costs associated with the advanced turbines that they are purchasing. Since these machines do not have fully established operation and maintenance (O&M) track records, power generators face financial risk due to uncertain future maintenance costs. This risk is of particular concern, as the electricity industry transitions to a competitive business environment in which unexpected O&M costs cannot be passed through to consumers. These concerns have accelerated the need for intelligent software-based diagnostic systems that can monitor the health of a combustion turbine in real time and provide valuable information on the machine's performance to its owner/operators. EPRI, Impact Technologies, Boyce Engineering, and Progress Energy have teamed to develop a suite of intelligent software tools integrated with a diagnostic monitoring platform that will, in real time, interpret data to assess the ''total health'' of combustion turbines. The Combustion Turbine Health Management System (CTHM) will consist of a series of dynamic link library (DLL) programs residing on a diagnostic monitoring platform that accepts turbine health data from existing monitoring instrumentation. The CTHM system will be a significant improvement over currently available techniques for turbine monitoring and diagnostics. CTHM will interpret sensor and instrument outputs, correlate …
Date: September 30, 2004
Creator: Angello, Leonard
Object Type: Report
System: The UNT Digital Library
Advanced Overfire Air system and design (open access)

Advanced Overfire Air system and design

The objective of the proposed project is to design, install and optimize a prototype advanced tangential OFA air system on two mass feed stoker boilers that can burn coal, biomass and a mixture of these fuels. The results will be used to develop a generalized methodology for retrofit designs and optimization of advanced OFA air systems. The advanced OFA system will reduce particulate and NOx emissions and improve overall efficiency by reducing carbon in the ash and excess oxygen. The advanced OFA will also provide capabilities for carrying full load and improved load following and transitional operations.
Date: July 30, 2004
Creator: berkau, Gene
Object Type: Report
System: The UNT Digital Library
Affirmative Action Revisited: A Legal History and Prospectus (open access)

Affirmative Action Revisited: A Legal History and Prospectus

Affirmative action remains a focal point of public debate as the result of legal and political developments at the federal, state, and local levels. This report discusses legislation related to affirmative action, as well as legal rulings on the topic and the federal government's role in first establishing and, later, attempting to curb affirmative action policies.
Date: January 30, 2004
Creator: Dale, Charles V.
Object Type: Report
System: The UNT Digital Library
Agricultural Conservation: USDA Should Improve Its Methods for Estimating Technical Assistance Costs (open access)

Agricultural Conservation: USDA Should Improve Its Methods for Estimating Technical Assistance Costs

A letter report issued by the Government Accountability Office with an abstract that begins "The U.S. Department of Agriculture's (USDA) Natural Resources Conservation Service (NRCS), working with state and local partners, provides landowners with technical assistance for multiple programs to plan and implement conservation measures that protect soil, water, and wildlife. For years, the Congress has been seeking detailed cost information on this assistance as it examined USDA budget requests. In part, because NRCS's financial system was not designed for estimating future budgets, in 1998 NRCS began developing additional cost data and a computer model for estimating future technical assistance costs. GAO was asked to (1) review NRCS's technical assistance cost estimates and (2) identify causes of any differences between the estimates and actual costs ultimately reported by NRCS."
Date: November 30, 2004
Creator: United States. Government Accountability Office.
Object Type: Report
System: The UNT Digital Library
ALS Performance Summary - Update (open access)

ALS Performance Summary - Update

High Energy Density Physics (HEDP) experiments play an important role in corroborating the improved physics codes that underlie LLNL's Stockpile Stewardship mission. Conducting these experiments, whether on the National Ignition Facility (NIF) or another national facility such as Omega, will require not only improvement in the diagnostics for measuring the experiment, but also detailed knowledge of the as-built target components and assemblies themselves. To assist in this effort, a defined set of well-known reference standards designed to represent a range of HEDP targets have been built and are being used to quantify the performance of different characterization techniques [Hibbard, et al. 2004]. Without the critical step of using reference standards for qualifying characterization tools there can be no verification of either commercial or internally-developed characterization techniques and thus an uncertainty in the input to the physics code models would exist.
Date: September 30, 2004
Creator: Waters, A M; Brown, W D & Martz, H. E., Jr.
Object Type: Report
System: The UNT Digital Library
The Alternative Minimum Tax for Individuals (open access)

The Alternative Minimum Tax for Individuals

This report provides a brief overview of the alternative minimum tax (AMT) for individuals, discusses the issues associated with the current system, and describes current legislation to amend the AMT. The report will be updated as legislative action warrants.
Date: April 30, 2004
Creator: Esenwein, Gregg A.
Object Type: Report
System: The UNT Digital Library
Alternative Transportation Fuels and Vehicles: Energy, Environment, and Development Issues (open access)

Alternative Transportation Fuels and Vehicles: Energy, Environment, and Development Issues

This report reviews several issues relating to alternative fuels and vehicles, mainly to combat dependence on petroleum imports and reduce greenhouse gas emissions. The report discusses the advantages and drawbacks of various alternative fuels and vehicles, as well as related legislation.
Date: June 30, 2004
Creator: Yacobucci, Brent D.
Object Type: Report
System: The UNT Digital Library
Ambient and elevated temperature fracture and cyclic-fatigue properties in a series of Al-containing silicon carbides (open access)

Ambient and elevated temperature fracture and cyclic-fatigue properties in a series of Al-containing silicon carbides

A series of in situ toughened, Al, B and C containing, silicon carbide ceramics (ABC-SiC) has been examined with Al contents varying from 3 to 7 wt%. With increasing Al additions, the grain morphology in the as-processed microstructures varied from elongated to bimodal to equiaxed, with a change in the nature of the grain-boundary film from amorphous to partially crystalline to fully crystalline. Fracture toughness and cyclic fatigue tests on these microstructures revealed that although the 7 wt.% Al containing material (7ABC) was extremely brittle, the 3 and particularly 5 wt.% Al materials (3ABC and 5ABC, respectively) displayed excellent crack-growth resistance at both ambient (25 C) and elevated (1300 C) temperatures. Indeed, no evidence of creep damage, in the form of grain-boundary cavitation, was seen at temperatures at 1300 C or below. The enhanced toughness of the higher Al-containing materials was associated with extensive crack bridging from both interlocking grains (in 3ABC) and uncracked ligaments (in 5ABC); in contrast, the 7ABC SiC showed no such bridging, concomitant with a marked reduction in the volume fraction of elongated grains. Mechanistically, cyclic fatigue-crack growth in 3ABC and 5ABC SiC involved the progressive degradation of such bridging ligaments in the crack wake, with …
Date: August 30, 2004
Creator: Yuan, Rong
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Ammonia-Free NOx Control System (open access)

Ammonia-Free NOx Control System

Research is being conducted under United States Department of Energy (DOE) Contract DEFC26-03NT41865 to develop a new technology to achieve very low levels of NOx emissions from pulverized coal fired boiler systems by employing a novel system level integration between the PC combustion process and the catalytic NOx reduction with CO present in the combustion flue gas. The combustor design and operating conditions will be optimized to achieve atypical flue gas conditions. This approach will not only suppress NOx generation during combustion but also further reduce NOx over a downstream catalytic reactor that does not require addition of an external reductant, such as ammonia. This report describes the work performed during the April 1 to June 30, 2004 time period.
Date: June 30, 2004
Creator: Fan, Zhen; Wu, Song & Herman, Richard G.
Object Type: Report
System: The UNT Digital Library
Ammonia-Free NOx Control System (open access)

Ammonia-Free NOx Control System

Research is being conducted under United States Department of Energy (DOE) Contract DEFC26-03NT41865 to develop a new technology to achieve very low levels of NOx emissions from pulverized coal fired boiler systems by employing a novel system level integration between the PC combustion process and the catalytic NOx reduction with CO present in the combustion flue gas. The combustor design and operating conditions will be optimized to achieve atypical flue gas conditions. This approach will not only suppress NOx generation during combustion but also further reduce NOx over a downstream catalytic reactor that does not require addition of an external reductant, such as ammonia. This report describes the work performed during the July 1 to September 30, 2004 time period.
Date: September 30, 2004
Creator: Wu, Song; Fan, Zhen; Seltzer, Andrew H. & Herman, Richard G.
Object Type: Report
System: The UNT Digital Library
Analysis of Homogeneous Charge Compression Ignition (HCCI) Engines for Cogeneration Applications (open access)

Analysis of Homogeneous Charge Compression Ignition (HCCI) Engines for Cogeneration Applications

This paper presents an evaluation of the applicability of Homogeneous Charge Compression Ignition Engines (HCCI) for small-scale cogeneration (less than 1 MWe) in comparison to five previously analyzed prime movers. The five comparator prime movers include stoichiometric spark-ignited (SI) engines, lean burn SI engines, diesel engines, microturbines and fuel cells. The investigated option, HCCI engines, is a relatively new type of engine that has some fundamental differences with respect to other prime movers. Here, the prime movers are compared by calculating electric and heating efficiency, fuel consumption, nitrogen oxide (NOx) emissions and capital and fuel cost. Two cases are analyzed. In Case 1, the cogeneration facility requires combined power and heating. In Case 2, the requirement is for power and chilling. The results show that the HCCI engines closely approach the very high fuel utilization efficiency of diesel engines without the high emissions of NOx and the expensive diesel fuel. HCCI engines offer a new alternative for cogeneration that provides a unique combination of low cost, high efficiency, low emissions and flexibility in operating temperatures that can be optimally tuned for cogeneration systems. HCCI engines are the most efficient technology that meets the oncoming 2007 CARB NOx standards for cogeneration …
Date: April 30, 2004
Creator: Aceves, S; Martinez-Frias, J & Reistad, G
Object Type: Article
System: The UNT Digital Library