(129)Xe NMR of Mesoporous Silicas (open access)

(129)Xe NMR of Mesoporous Silicas

The porosities of three mesoporous silica materials were characterized with {sup 129}Xe NMR spectroscopy. The materials were synthesized by a sol-gel process with r = 0, 25, and 70% methanol by weight in an aqueous cetyltrimethylammonium bromide solution. Temperature dependent chemical shifts and spin lattice relaxation times reveal that xenon does not penetrate the pores of the largely disordered (r= 70%) silica. For both r = 0 and 25%, temperature dependent resonances corresponding to physisorbed xenon were observed. An additional resonance for the r = 25% sample was attributed to xenon between the disordered cylindrical pores. 2D NMR exchange experiments corroborate the spin lattice relaxation data which show that xenon is in rapid exchange between the adsorbed and the gas phase.
Date: April 23, 1999
Creator: Anderson, M.T.; Asink, R.A.; Kneller, J.M. & Pietrass, T.
Object Type: Article
System: The UNT Digital Library
1999 Gordon Research Conference on Microbial Population Biology. Final Progress Report (open access)

1999 Gordon Research Conference on Microbial Population Biology. Final Progress Report

None
Date: July 23, 1999
Creator: unknown
Object Type: Article
System: The UNT Digital Library
1999 Leak Detection and Monitoring and Mitigation Strategy Update (open access)

1999 Leak Detection and Monitoring and Mitigation Strategy Update

This document is a complete revision of WHC-SD-WM-ES-378, Rev 1. This update includes recent developments in Leak Detection, Leak Monitoring, and Leak Mitigation technologies, as well as, recent developments in single-shell tank retrieval technologies. In addition, a single-shell tank retrieval release protection strategy is presented.
Date: September 23, 1999
Creator: Ohl, Phil
Object Type: Report
System: The UNT Digital Library
29th Annual PolyMAC Meeting: Book of Abstracts (open access)

29th Annual PolyMAC Meeting: Book of Abstracts

A sixteen-run, Resolution IV, fractional factorial screening design has been used to evaluate the relative significance of seven independent material and process variables for an electrically deposited commercial acrylic paint. A Resolution IV design was chosen so that variable interactions could be detected without any interference from the effects of the variables themselves. Because resource limitations did not permit use of a Resolution V design, the two-way interactions were confounded with one another in groups of three, which unfortunately made interpretation of the results more complicated. Each design point was replicated once and a pair of centerpoints were run at the beginning, in the middle and at the end of the design points. A total of 38 test panels were prepared. Independent variables used in this experiment were total charge, current density, mixer speed, silica content, crossover point, temperature and solids fraction. The magnitude of each independent variable's effect on the dependent response variables was estimated by fitting a first-order model with two-way interaction terms. Three-way interactions were assumed to be insignificant. Interaction confounding was eliminated by using the significance of the independent variables to determine which of the three possible interactions was significant. Data analysis was performed using the …
Date: July 23, 1999
Creator: Balazs, B.
Object Type: Report
System: The UNT Digital Library
2nd Generation PFBC Systems R&D Phase 2 AND Phase 3 (open access)

2nd Generation PFBC Systems R&D Phase 2 AND Phase 3

No work was performed; the two remaining Multi Annular Swirl Burner test campaigns are on hold pending selection of a new test facility (replacement for the shut down UTSI burner test facility) and identification of associated testing costs. The Second-Generation PFB Combustion Plant conceptual design prepared in 1987 is being updated to reflect the benefit of pilot plant test data and the latest advances in gas turbine technology. The updated plant is being designed to operate with 95 percent sulfur capture and a single Siemens Westinghouse (SW) 501G gas turbine. Using carbonizer and gas turbine data generated by Foster Wheeler (FW) and SW respectively, Parsons Energy and Chemicals Group prepared preliminary plant heat and materials based on carbonizer operating temperatures of 1700 and 1800 F and found the former to yield the higher plant efficiency. As a result, 1700EF has been selected as the preferred operating condition for the carbonizer. The previous first cut plant heat and material balance was refined and it predicts a 47.7% plant efficiency (HHV) with a net power output of 421 MWe. The latter includes a plant auxiliary load estimated to be 23.48 MWe or 5.26% of the gross plant power and a transformer loss …
Date: December 23, 1999
Creator: Robertson, Archie
Object Type: Report
System: The UNT Digital Library
Acceptable Knowledge Summary Report for Waste Stream: SR-T001-221F-HET/Drums (open access)

Acceptable Knowledge Summary Report for Waste Stream: SR-T001-221F-HET/Drums

Since beginning operations in 1954, the Department of Energy's Savannah River Site FB-Line conducted atomic energy defense activities consistent with the listing in Section 10101(3) of the Nuclear Waste Policy Act of 1982. The facility mission was to process and convert dilute plutonium solution into highly purified weapons grade plutonium metal. As a result of various activities conducted in support of the mission (e.g., operation, maintenance, repair, clean up, and facility modifications), the facility generated transuranic waste. This document, along with referenced supporting documents, provides a defensible and auditable record of acceptable knowledge for one of the waste streams from the FB-Line. The waste was packaged in 55-gallon drums, then shipped to the transuranic waste storage facility in ''E'' area of the Savannah River Site. This acceptable knowledge report includes information relating to the facility's history, configuration,equipment, process operations, and waste management practices.
Date: August 23, 1999
Creator: Lunsford, G.F.
Object Type: Report
System: The UNT Digital Library
Achieving high sustained performance in an unstructured mesh CFD application. (open access)

Achieving high sustained performance in an unstructured mesh CFD application.

None
Date: August 23, 1999
Creator: Anderson, W. K.; Gropp, W. D.; Kaushik, D. K.; Keyes, D. E. & Smith, B. F.
Object Type: Article
System: The UNT Digital Library
Activation and Micropore Structure Determination of Activated Carbon-Fiber Composites (open access)

Activation and Micropore Structure Determination of Activated Carbon-Fiber Composites

Previous work focused on the production of carbon fiber composites and subsequently activating them to induce adsorbent properties. One problem related to this approach is the difficulty of uniformly activating large composites. In order to overcome this problem, composites have been made from pre-activated fibers. The loss of surface area upon forming the composites after activation of the fibers was investigated. The electrical resistivity and strength of these composites were compared to those made by activation after forming. It was found that the surface area is reduced by about 35% by forming the composite from pre-activated fibers. However, the properties of the activated sample are very uniform: the variation in surface area is less than {+-}0.5%. So, although the surface area is somewhat reduced, it is believed that making composites from pre-activated fibers could be useful in applications where the BET surface area is not required to be very high. The strength of the composites produced from pre-activated fibers is lower than for composites activated after forming when the carbon burnoff is below 45%. For higher burnoffs, the strength of composites made with pre-activated fibers is as good or better. In both cases, there is a dramatic decrease in strength …
Date: April 23, 1999
Creator: Jagtoyen, M. & Derbyshire, F.
Object Type: Report
System: The UNT Digital Library
Advisor 2.0: A Second-Generation Advanced Vehicle Simulator for Systems Analysis (open access)

Advisor 2.0: A Second-Generation Advanced Vehicle Simulator for Systems Analysis

The National Renewable Energy Laboratory has recently publicly released its second-generation advanced vehicle simulator called ADVISOR 2.0. This software program was initially developed four years ago, and after several years of in-house usage and evolution, the tool is now available to the public through a new vehicle systems analysis World Wide Web page. ADVISOR has been applied to many different systems analysis problems, such as helping to develop the SAE J1711 test procedure for hybrid vehicles and helping to evaluate new technologies as part of the Partnership for a New Generation of Vehicles (PNGV) technology selection process. The model has been and will continue to be benchmarked and validated with other models and with real vehicle test data. After two months of being available on the Web, more than 100 users have downloaded ADVISOR. ADVISOR 2.0 has many new features, including an easy-to-use graphical user interface, a detailed exhaust aftertreatment thermal model, and complete browser-based documentation. Future work will include adding to the library of components available in ADVISOR, including optimization functionality, and linking with a more detailed fuel cell model.
Date: March 23, 1999
Creator: Wipke, K.; Cuddy, M.; Bharathan, D.; Burch, S.; Johnson, V.; Markel, A. et al.
Object Type: Report
System: The UNT Digital Library
Aerosol-Assisted Self-Assembly of Mesostructured Spherical Nanoparticles (open access)

Aerosol-Assisted Self-Assembly of Mesostructured Spherical Nanoparticles

Nanostructured particles exhibiting well-defined pore sizes and pore connectivities (1-, 2-, or 3-dimensional) are of interest for catalysis, chromatography, controlled release, low dielectric constant fillers, and custom-designed pigments and optical hosts. During the last several years considerable progress has been made on controlling the macroscopic forms of mesoporous silicas prepared by surfactant and block copolymer liquid crystalline templating procedures. Typically interfacial phenomena are used to control the macroscopic form (particles, fibers, or films), while self-assembly of amphiphilic surfactants or polymers is used to control the mesostructure. To date, although a variety of spherical or nearly-spherical particles have been prepared, their extent of order is limited as is the range of attainable mesostructures. They report a rapid, aerosol process that results in solid, completely ordered spherical particles with stable hexagonal, cubic, or vesicular mesostructures. The process relies on evaporation-induced interfacial self-assembly (EISA) confined to a spherical aerosol droplet. The process is simple and generalizable to a variety of materials combinations. Additionally, it can be modified to provide the first aerosol route to the formation of ordered mesostructured films.
Date: March 23, 1999
Creator: Lu, Yunfeng; Fan, Hongyou; Stump, Aaron; Ward, Timothy, L.; Rieker, Thomas & Brinker, C. Jeffrey
Object Type: Article
System: The UNT Digital Library
Alternative Fuel News, Vol. 3 No. 2 (open access)

Alternative Fuel News, Vol. 3 No. 2

This special issue of Alternative Fuel News highlights the Fifth National Clean Cities Conference held in Louisville, Kentucky. The momentum for the program is stronger than ever and the coalitions are working to propel the alternative fuel industry forward.
Date: September 23, 1999
Creator: unknown
Object Type: Book
System: The UNT Digital Library
Amorphization of Laves-Phase Precipitates in Zircaloy-4 by Neutron Irradiation (open access)

Amorphization of Laves-Phase Precipitates in Zircaloy-4 by Neutron Irradiation

Examination of corrosion coupons by transmission electron microscopy after their exposure in the Idaho Advanced Test Reactor (ATR) has broadened the Zircaloy-4 precipitate-amorphization database and validated a new kinetic model for previously unavailable values of temperature and fast-neutron flux. The model describes the amorphization of Zr(Fe,Cr){sub 2} intermetallic precipitates in zirconium alloys as a dynamic competition between radiation damage and thermal annealing that leaves some iron atoms available for flux-assisted diffusion to the zirconium matrix. It predicts the width of the amorphous zone as a function of neutron flux (E>1 MeV), temperature, and time. In its simplest form, the model treats the crystalline/amorphous and precipitate/matrix interfaces as parallel planes, and its accuracy decreases for small precipitates and high fluence as the amorphous-zone width approaches precipitate dimensions. The simplest form of the model also considers diffusion to be rate-determining. This is an accurate approximation for steady-state conditions or slow changes in flux and temperature, but inappropriate for the analysis of faster transients. The paper addresses several difficulties inherent in measuring amorphous-zone width, and utilizes the expanded database to evaluate the improvements in predictive accuracy available through both conversion of the model to spherical coordinates and extension of its time dependency.
Date: April 23, 1999
Creator: Peters, H. R.; Taylor, D. F. & Yang, Walter J. S.
Object Type: Article
System: The UNT Digital Library
Analysis, comparison, and modeling of radar interferometry, date of surface deformation signals associated with underground explosions, mine collapses and earthquakes. Phase I: underground explosions, Nevada Test Site (open access)

Analysis, comparison, and modeling of radar interferometry, date of surface deformation signals associated with underground explosions, mine collapses and earthquakes. Phase I: underground explosions, Nevada Test Site

We have previously presented simple elastic deformation modeling results for three classes of seismic events of concern in monitoring the CTBT--underground explosions, mine collapses and earthquakes. Those results explored the theoretical detectability of each event type using synthetic aperture radar interferometry (InSAR) based on commercially available satellite data. In those studies we identified and compared the characteristics of synthetic interferograms that distinguish each event type, as well the ability of the interferograms to constrain source parameters. These idealized modeling results, together with preliminary analysis of InSAR data for the 1995 mb 5.2 Solvay mine collapse in southwestern Wyoming, suggested that InSAR data used in conjunction with regional seismic monitoring holds great potential for CTBT discrimination and seismic source analysis, as well as providing accurate ground truth parameters for regional calibration events. In this paper we further examine the detectability and ''discriminating'' power of InSAR by presenting results from InSAR data processing, analysis and modeling of the surface deformation signals associated with underground explosions. Specifically, we present results of a detailed study of coseismic and postseismic surface deformation signals associated with underground nuclear and chemical explosion tests at the Nevada Test Site (NTS). Several interferograms were formed from raw ERS-1/2 radar …
Date: July 23, 1999
Creator: Foxall, W; Vincent, P & Walter, W
Object Type: Article
System: The UNT Digital Library
Analysis of the Interaction of Short-Pulse High-Fluence Radiation with Targets (open access)

Analysis of the Interaction of Short-Pulse High-Fluence Radiation with Targets

We generally use large-scale hydrocodes to study the dynamic response of targets to influence pulsed radiation loads. However, for many applications where the desired solution does not require a detailed specification of pressure- or velocity-time histories, there are simple analytic approaches that can yield surprisingly accurate results. Examples include determining either the final velocity of a radiation-driven flying plate or the impulse delivered to a structural element. These methods are all based on relatively straightforward use of conservation of mass and momentum, but they typically need one scaling-law parameter. In this context, short pulse means short compared to the characteristic time of the desired response, which allows for the phenomena to be essentially uncoupled. High fluence means that the input energy is great enough to yield vaporization or blowoff of one or more portions of the configuration. We discuss some of these methods, give examples, and suggest limitations and criteria for their use.
Date: July 23, 1999
Creator: Lawrence, R.Jeffery
Object Type: Article
System: The UNT Digital Library
AntiReflection Coating D (open access)

AntiReflection Coating D

Analytical expressions used to optimize AR coatings for single junction solar cells are extended for use in monolithic, series interconnected multi-junction solar cell AR coating design. The result is an analytical expression which relates the solar cell performance (through J{sub sc}) directly to the AR coating design through the device reflectance. It is also illustrated how AR coating design be used to provide an additional degree of freedom for current matching multi-junction devices.
Date: September 23, 1999
Creator: AIKEN,DANIEL J.
Object Type: Article
System: The UNT Digital Library
An Apparatus for the Direct Measurement of Collimator Transverse Wakefields (open access)

An Apparatus for the Direct Measurement of Collimator Transverse Wakefields

The design of the NLC Beam Delivery System requires a firmer understanding of the effects of collimators on short, intense bunches than is presently available. We describe an experiment to directly measure these effects through use of a dedicated apparatus located at the 1.19 GeV point in the SLAC Linac. The apparatus consists of an outer vacuum vessel and an interchangeable insertion containing up to 5 distinct collimator apertures. The insertion is capable of remote-controlled translation, allowing the collimator apertures to be misaligned relative to the electron beam without changing the incoming beam orbit; the wakefield deflection is then measured by observing the change in the outgoing orbit on 32 beam position monitors. The parameters of the apertures have been selected to allow confirmation of the scaling laws for collimator wakefields, and to strongly enhance either the geometric or resistive wall contribution of each aperture. Details of the apparatus design, the aperture parameters, and the experimental program are discussed.
Date: April 23, 1999
Creator: Tenenbaum, Peter G
Object Type: Report
System: The UNT Digital Library
Application of ''Confirm tank T is an appropriate feed source for High-Level waste feed batch X'' to specific feed batches (open access)

Application of ''Confirm tank T is an appropriate feed source for High-Level waste feed batch X'' to specific feed batches

This document addresses the characterization needs of tanks as set forth in the Data Quality Objectives for TWRS Privatization Phase I: Confirm Tank T is an Appropriate Feed Source for High-Level Waste Feed Batch X (Crawford et al. 1998). The primary purpose of this document is to collect existing data and identify the data needed to determine whether or not the feed source(s) are appropriate for a specific batch. To answer these questions, the existing tank data must be collected and a detailed review performed. If the existing data are insufficient to complete a full comparison, additional data must be obtained from the feed source(s). Additional information requirements need to be identified and formally documented, then the source tank waste must be sampled or resampled and analyzed. Once the additional data are obtained, the data shall be incorporated into the existing database for the source tank and a reevaluation of the data against the Data Quality Objective (DQO) must be made.
Date: February 23, 1999
Creator: JO, J.
Object Type: Report
System: The UNT Digital Library
Application of ''Confirm tank T is an appropriate feed source for Low-Activity waste feed batch X'' to specific feed batches (open access)

Application of ''Confirm tank T is an appropriate feed source for Low-Activity waste feed batch X'' to specific feed batches

This document addresses the characterization needs of tanks as set forth in the ''Confirm Tank T is an Appropriate Feed Source for Low-Activity Waste Feed Batch X'' Data Quality Objective (DQO) (Certa and Jo 1998). The primary purpose of this document is to collect existing data and identify the data needed to determine whether or not the feed source(s) are appropriate for a specific batch before transfer is made to the feed staging tanks. To answer these questions, the existing tank data must be collected and a detailed review performed. If the existing data are insufficient to complete a full comparison, additional data must be obtained from the feed source(s). Additional information requirements need to be identified and formally documented, then the source tank waste must be sampled or resampled and analyzed. Once the additional data are obtained, the data shall be incorporated into the existing database for the source tank and a reevaluation of the data against the DQO must be made.
Date: February 23, 1999
Creator: JO, J.
Object Type: Report
System: The UNT Digital Library
Application of the Pegasus II Pulsed-Power Facility to the Study of Inertial Instability and Fracture of Cylindrical Tubes of Solid Aluminum (open access)

Application of the Pegasus II Pulsed-Power Facility to the Study of Inertial Instability and Fracture of Cylindrical Tubes of Solid Aluminum

Understanding the surface stability of metals undergoing dynamic fracture at shock breakout is important to several applications in metals processing. The advantages of using the Pegasus II facility to investigate the phenomena occurring at shock break out are described. As an example of the data collected, we concentrate on brief descriptions of two experiments that compared the tensile failure, i.e. ''spall'', patterns in the presence of sinusoidal perturbations seeded on the free inner surface of cylindrical samples of 3 types of Al. These samples were composed variously of soft Al 1100-O, structural grade Al 6061-T6, and ultra-pure 99.99% Al and were subjected to Taylor waves with shock pressures of 14 GPa. We show that the material behind the exiting surface undergoes a type of failure termed here ''microspall'', resulting in the production of a significant volume of low-density, probably granular, material. The failure mechanism, combined with the forces that cause inertial instability, leads to rapid pattern growth in the failed material and subsequent pattern growth on the surface. Pattern growth was studied as a function of perturbation wavelength and amplitude. The different Al samples vary by an order of magnitude in yield strength, and some increase in pattern instability was …
Date: June 23, 1999
Creator: Chandler, E. A.; Stokes, J.; Fulton, R. D.; Morgan, D. V.; Obst, A. W.; Oro, D. M. et al.
Object Type: Report
System: The UNT Digital Library
The Ascension Island hydroacoustic experiment: purpose, data set features and plans for future analysis (open access)

The Ascension Island hydroacoustic experiment: purpose, data set features and plans for future analysis

Calibration of hydroacoustic and T-phase stations for Comprehensive Nuclear-Test-Ban Treaty (CTBT) monitoring will be an important element in establishing new operational stations and upgrading existing stations. Calibration of hydroacoustic stations is herein defined as precision location of the hydrophones and determination of the amplitude response from a known source energy. T-phase station calibration is herein defined as a determination of station site attenuation as a function of frequency, bearing, and distance for known impulsive energy sources in the ocean. To understand how to best conduct calibration experiments for both hydroacoustic and T-phase stations, an experiment was conducted in May, 1999 at Ascension Island in the South Atlantic Ocean. The experiment made use of a British oceanographic research vessel and collected data that will be used for CTBT issues and for fundamental understanding of the Ascension Island volcanic edifice.
Date: July 23, 1999
Creator: Harben, P E; Rock, D & Rodgers, A J
Object Type: Article
System: The UNT Digital Library
Authorization basis for the 209-E Building (open access)

Authorization basis for the 209-E Building

This Authorization Basis document is one of three documents that constitute the Authorization Basis for the 209-E Building. Per the U.S. Department of Energy, Richland Operations Office (RL) letter 98-WSD-074, this document, the 209-E Building Preliminary Hazards Analysis (WHC-SD-WM-TI-789), and the 209-E Building Safety Evaluation Report (97-WSD-074) constitute the Authorization Basis for the 209-E Building. This Authorization Basis and the associated controls and safety programs will remain in place until safety documentation addressing deactivation of the 209-E Building is developed by the contractor and approved by RL.
Date: February 23, 1999
Creator: TIFFANY, M.S.
Object Type: Report
System: The UNT Digital Library
AX Tank farm soil remediation study (open access)

AX Tank farm soil remediation study

None
Date: March 23, 1999
Creator: SKELLY, W.A.
Object Type: Report
System: The UNT Digital Library
Ballistic Experiments with Titanium and Aluminum Targets (open access)

Ballistic Experiments with Titanium and Aluminum Targets

During the course of the project we conducted two sets of fundamental experiments in penetration mechanics in the LLNL Terminal Ballistics Laboratory of the Physics Directorate. The first set of full-scale experiments was conducted with a 14.5mm air propelled launcher. The object of the experiments was to determine the ballistic limit speed of 6Al-4V-alloy titanium, low fineness ratio projectiles centrally impacting 2024-T3 alloy aluminum flat plates and the failure modes of the projectiles and the targets. The second set of one-third scale experiments was conducted with a 14.5mm powder launcher. The object of these experiments was to determine the ballistic limit speed of 6Al-4V alloy titanium high fineness ratio projectiles centrally impacting 6Al-4V alloy titanium flat plates and the failure modes of the projectiles and the target. We employed radiography to observe a projectile just before and after interaction with a target plate. Early on, we employed a non-damaging ''soft-catch'' technique to capture projectiles after they perforated targets. Once we realized that a projectile was not damaged during interaction with a target, we used a 4-inch thick 6061-T6-alloy aluminum witness block with a 6.0-inch x 6.0-inch cross-section to measure projectile residual penetration. We have recorded and tabulated below projectile impact …
Date: November 23, 1999
Creator: Gogolewski, R. & Morgan, B. R.
Object Type: Report
System: The UNT Digital Library
The beamline for the second axis of the dual axis radiographic hydrodynamic test facility (open access)

The beamline for the second axis of the dual axis radiographic hydrodynamic test facility

During normal DARHT II operation, the beam exiting the accelerator will be well characterized by its nominal design parameters of 20-MeV, 2000-Amperes, 2-{micro}sec-pulse length, and 3 cm-mr unnormalized emittance. Normal operation will have the beam delivered to a beam dump via several DC magnets. A 2-way kicker magnet is used to deflect portions of the beam into the straight ahead beamline leading to either a diagnostic beamline or to the converter target beamline. During start up and or beam development periods, the beam exiting the accelerator may have parameters outside the acceptable range of values for normal operation. The Enge beamline must accommodate this range of unacceptable beam parameters, delivering the entire 80 KiloJoule of beam to the dump even though the energy, emittance, and/or match is outside the nominal design range.
Date: March 23, 1999
Creator: Caporaso, G. J.; Chen, Y. J.; Fawley, W. M.; Lee, E. P.; Paul, A. C. & Westenkow, G.
Object Type: Article
System: The UNT Digital Library