Materials Evaluation Test Series (METS) 04, 05, and 06 (open access)

Materials Evaluation Test Series (METS) 04, 05, and 06

The purpose of this work is to examine the environmental, safety, health and operational aspects of detonating a confined explosive test apparatus that has been designed to maximize the dynamics of impact on beryllium metal components for Contained Firing Facility (CFF) applications. A combination of experimental collection and evaluation methods were designed and implemented to provide an evaluation of immediately postdetonation by-products reflecting a potential worst-case scenario beryllium aerosolization explosive event. The collective Material Evaluation Test Series (METS) 04 - 06 provided explosive devices designed to scale for the dedicated METS firing tank that would provide a post-detonation internal environment comparable to the CFF. The experimental results provided appropriate information to develop operational parameters to be considered for conducting full-scale beryllium-containing experimental tests with similar designs within CFF and B801A. These operational procedures include the inclusion of chelating agents in pre-shot CFF cardboard containers with a minimum of 600 gallons content, an extended time period post-test before purging the CFF chamber, and an adaptation of approaches toward applications of the scrubber and HEPA systems during the post-shot sequence for an integrated environmental, safety, and health approach. In addition, re-entry and film retrieval procedures will be adapted, in line with abatement …
Date: March 23, 2006
Creator: Zalk, D.; Ingram, C.; Simmons, L.; Arganbright, R.; Lyle, J. & Wong, K.
Object Type: Report
System: The UNT Digital Library
Stark Tuning of Donor Electron Spins of Silicon (open access)

Stark Tuning of Donor Electron Spins of Silicon

We report Stark shift measurements for {sup 121}Sb donor electron spins in silicon using pulsed electron spin resonance. Interdigitated metal gates on top of a Sb-implanted {sup 28}Si epi-layer are used to apply electric fields. Two Stark effects are resolved: a decrease of the hyperfine coupling between electron and nuclear spins of the donor and a decrease in electron Zeeman g-factor. The hyperfine term prevails at X-band magnetic fields of 0.35T, while the g-factor term is expected to dominate at higher magnetic fields. A significant linear Stark effect is also resolved presumably arising from strain.
Date: March 23, 2006
Creator: Bradbury, Forrest R.; Tyryshkin, Alexei M.; Sabouret, Guillaume; Bokor, Jeff; Schenkel, Thomas & Lyon, Stephen A.
Object Type: Article
System: The UNT Digital Library
Vlt and Acs Observations of RDCS J1252.9-2927: Dynamical Structure and Galaxy Populations in a Massive Cluster at Z=1.237* (open access)

Vlt and Acs Observations of RDCS J1252.9-2927: Dynamical Structure and Galaxy Populations in a Massive Cluster at Z=1.237*

We present results from an extensive spectroscopic survey, carried out with FORS on the ESO Very Large Telescope, and from an extensive multi-wavelength imaging data set from the Advanced Camera for Surveys and ground based facilities of the cluster of galaxies RDCS J1252.9-2927. We have spectroscopically confirmed 38 cluster members in the redshift range 1.22 < z < 1.25. The distribution in velocity of these spectroscopic members yields a cluster median redshift of z = 1.237 and a rest-frame velocity dispersion of 747{sub -84}{sup +74} km s{sup -1}. Star-forming members are observed to mainly populate the outskirts of the cluster while passive galaxies dominate the central cluster region. Using the 38 confirmed redshifts, we were able to resolve, for the first time at z > 1, kinematic structure. The velocity distribution, which is not Gaussian at the 95% confidence level, is consistent with two groups that are also responsible for the projected elongation of the cluster in the East-West direction. The groups are composed of 26 and 12 galaxies and have velocity dispersions of 486{sub -85}{sup +47} km s{sup -1} and 426{sub -105}{sup +57} km s{sup -1}, respectively. The elongation is also seen in the intracluster gas (from X-ray observations) …
Date: March 23, 2007
Creator: Demarco, R.; Rosati, P.; Lidman, C.; Girardi, M.; Nonino, M.; Rettura, A. et al.
Object Type: Article
System: The UNT Digital Library
Influence of argon and oxygen on charge-state-resolved ion energydistributions of filtered aluminum arcs (open access)

Influence of argon and oxygen on charge-state-resolved ion energydistributions of filtered aluminum arcs

The charge-state-resolved ion energy distributions (IEDs) in filtered aluminum vacuum arc plasmas were measured and analyzed at different oxygen and argon pressures in the range 0.5 8.0 mTorr. A significant reduction of the ion energy was detected as the pressure was increased, most pronounced in an argon environment and for the higher charge states. The corresponding average charge state decreased from 1.87 to 1.0 with increasing pressure. The IEDs of all metal ions in oxygen were fitted with shifted Maxwellian distributions. The results show that it is possible to obtain a plasma composition with a narrow charge-state distribution as well as a narrow IED. These data may enable tailoring thin-film properties through selecting growth conditions that are characterized by predefined charge state and energy distributions.
Date: March 23, 2006
Creator: Rosen, Johanna; Anders, Andre; Mraz, Stanislav; Atiser, Adil & Schneider, Jochen M.
Object Type: Article
System: The UNT Digital Library
Hydrologic Resources Management Program and Underground Test Area Project FY2005 Progress Report (open access)

Hydrologic Resources Management Program and Underground Test Area Project FY2005 Progress Report

This report describes FY 2005 technical studies conducted by the Chemical Biology and Nuclear Science Division (CBND) at Lawrence Livermore National Laboratory (LLNL) in support of the Hydrologic Resources Management Program (HRMP) and the Underground Test Area Project (UGTA). These programs are administered by the U.S. Department of Energy, National Nuclear Security Administration, Nevada Site Office (NNSA/NSO) through the Defense Programs and Environmental Restoration Divisions, respectively. HRMP-sponsored work is directed toward the responsible management of the natural resources at the Nevada Test Site (NTS), enabling its continued use as a staging area for strategic operations in support of national security. UGTA-funded work emphasizes the development of an integrated set of groundwater flow and contaminant transport models to predict the extent of radionuclide migration from underground nuclear testing areas at the NTS. The report is organized on a topical basis and contains five chapters that highlight technical work products produced by CBND. However, it is important to recognize that most of this work involves collaborative partnerships with the other HRMP and UGTA contract organizations. These groups include the Energy and Environment Directorate at LLNL (LLNL-E&E), Los Alamos National Laboratory (LANL), the Desert Research Institute (DRI), the U.S. Geological Survey (USGS), Stoller-Navarro …
Date: March 23, 2007
Creator: Eaton, G. F.; Genetti, V.; Hu, Q.; Hudson, G. B.; Kersting, A. B.; Lindvall, R. E. et al.
Object Type: Report
System: The UNT Digital Library
Nano-subgrain Strengthening in Ball-milled Iron (open access)

Nano-subgrain Strengthening in Ball-milled Iron

The strength and deformation behavior of ball-milled, iron-base materials containing nano-scale subgrains have been evaluated. As reported by several authors, nanosubgrains form during the early stages of ball milling as a result of severe plastic deformation inherent in the ball milling process. The strength for these nano-scale subgrains are compared with the strength of larger-scale subgrains in iron and iron-base alloys produced by traditional mechanical working. The data covers over 2 orders of magnitude in subgrain size (from 30 nm to 6 {micro}m) and shows a continuous pattern of behavior. For all materials studied, the strength varied as {lambda}{sup -1}, where {lambda} is the subgrain size. Strengthening from subgrains was found to breakdown at a much smaller subgrain size than strengthening from grains. In addition, the ball-milled materials showed significant strengthening contributions from nano-scale oxide particles. Shear bands are developed during testing of ball-milled materials containing ultra-fine subgrains. A model for shear band development in nano-scale subgrains during deformation has also been developed. The model predicts a strain state of uniaxial compression in the shear band with a strain of -1.24. Subgrains are shown to offer the opportunity for high strength and good work hardening with the absence of yield …
Date: March 23, 2006
Creator: Lesuer, D R; Syn, C K & Sherby, O D
Object Type: Article
System: The UNT Digital Library
Formation, Stability, and Mobility of One-Dimensional Lipid Bilayer on High Curvature Substrates (open access)

Formation, Stability, and Mobility of One-Dimensional Lipid Bilayer on High Curvature Substrates

Curved lipid membranes are ubiquitous in living systems and play an important role in many biological processes. To understand how curvature and lipid composition affect membrane formation and fluidity we have assembled and studied mixed 1,2-Dioleoyl-sn-Glycero-3-Phosphocholine (DOPC) and 1,2-Dioleoyl-sn-Glycero-3-Phosphoethanolamine (DOPE) supported lipid bilayers on amorphous silicon nanowires with controlled diameters ranging from 20 nm to 200 nm. Addition of cone-shaped DOPE molecules to cylindrical DOPC molecules promotes vesicle fusion and bilayer formation on smaller diameter nanowires. Our experiments demonstrate that nanowire-supported bilayers are mobile, exhibit fast recovery after photobleaching, and have low concentration of defects. Lipid diffusion coefficients in these high-curvature tubular membranes are comparable to the values reported for flat supported bilayers and increase with decreasing nanowire diameter.
Date: March 23, 2007
Creator: Huang, J.; Martinez, J.; Artyukhin, A.; Sirbuly, D.; Wang, Y.; Ju, J. W. et al.
Object Type: Article
System: The UNT Digital Library
Effect of solution saturation state and temperature on diopside dissolution (open access)

Effect of solution saturation state and temperature on diopside dissolution

Steady-state dissolution rates of diopside are measured as a function of solution saturation state using a titanium flow-through reactor at pH 7.5 and temperature ranging from 125 to 175 C. Diopside dissolved stoichiometrically under all experimental conditions and rates were not dependent on sample history. At each temperature, rates continuously decreased by two orders of magnitude as equilibrium was approached and did not exhibit a dissolution plateau of constant rates at high degrees of undersaturation. The variation of diopside dissolution rates with solution saturation can be described equally well with a ion exchange model based on transition state theory or pit nucleation model based on crystal growth/dissolution theory from 125 to 175 C. At 175 C, both models over predict dissolution rates by two orders of magnitude indicating that a secondary phase precipitated in the experiments. The ion exchange model assumes the formation of a Si-rich, Mg-deficient precursor complex. Lack of dependence of rates on steady-state aqueous calcium concentration supports the formation of such a complex, which is formed by exchange of protons for magnesium ions at the surface.
Date: March 23, 2007
Creator: Dixit, S & Carroll, S A
Object Type: Article
System: The UNT Digital Library
Nonlinear optical absorption in laser modified regions of fused silica substrates (open access)

Nonlinear optical absorption in laser modified regions of fused silica substrates

The presence of strong nonlinear absorption has been observed in laser modified fused silica. Intensity-dependent transmission measurements using 355-nm, 532-nm and 1,064-nm laser pulses were performed in pristine polished regions in fused silica substrates and in locations that were exposed to dielectric breakdown. The experimental results suggest that multi-photon absorption is considerably stronger in the modified regions compared to pristine sites and is strongly dependent on the excitation wavelength.
Date: March 23, 2004
Creator: Walser, A D; Demos, S; Etienne, M & Dorsinville, R
Object Type: Article
System: The UNT Digital Library
Thermal Decomposition of Trinitrotoluene (TNT) with a New One-Dimensional Time to Explosion (ODTX) Apparatus (open access)

Thermal Decomposition of Trinitrotoluene (TNT) with a New One-Dimensional Time to Explosion (ODTX) Apparatus

The thermal explosion of trinitrotoluene (TNT) is used as a basis for evaluating the performance of a new One-Dimensional-Time-to-Explosion (ODTX) apparatus. The ODTX experiment involves holding a 12.7 mm-diameter spherical explosive sample under confinement (150 MPa) at a constant elevated temperature until the confining pressure is exceeded by the evolution of gases during chemical decomposition. The resulting time to explosion as a function of temperature provides valuable decomposition kinetic information. A comparative analysis of the measurements obtained from the new unit and an older system is presented. Discussion on selected performance aspects of the new unit will also be presented. The thermal explosion of TNT is highly dependent on the material. Analysis of the time to explosion is complicated by historical and experimental factors such as material variability, sample preparation, temperature measurement and system errors. Many of these factors will be addressed. Finally, a kinetic model using a coupled thermal and heat transport code (chemical TOPAZ) was used to match the experimental data.
Date: March 23, 2001
Creator: Tran, T. D.; Simpson, R. L.; Maienschein, J. & Tarver, Craig M.
Object Type: Article
System: The UNT Digital Library
A Layer MDT Octant Supprt Analysis (open access)

A Layer MDT Octant Supprt Analysis

None
Date: March 23, 2000
Creator: Levand, T.
Object Type: Report
System: The UNT Digital Library
Co-ordination of the International Network of Nuclear Structure and Decay Data Evaluators; Summary Report of an IAEA Technical Meeting (open access)

Co-ordination of the International Network of Nuclear Structure and Decay Data Evaluators; Summary Report of an IAEA Technical Meeting

The IAEA Nuclear Data Section convened the 18th meeting of the International Network of Nuclear Structure and Decay Data Evaluators at the IAEA Headquarters, Vienna, 23 to 27 March 2009. This meeting was attended by 22 scientists from 14 Member States, plus IAEA staff, concerned with the compilation, evaluation and dissemination of nuclear structure and decay data. A summary of the meeting, recommendations/conclusions, data centre reports, and various proposals considered, modified and agreed by the participants are contained within this document. The International Network of Nuclear Structure and Decay Data (NSDD) Evaluators holds biennial meetings under the auspices of the IAEA, and consists of evaluation groups and data service centres in several countries. This network has the objective of providing up-to-date nuclear structure and decay data for all known nuclides by evaluating all existing experimental data. Data resulting from this international evaluation collaboration is included in the Evaluated Nuclear Structure Data File (ENSDF) and published in the journals Nuclear Physics A and Nuclear Data Sheets (NDS).
Date: March 23, 2009
Creator: Abriola, D. & Tuli, J.
Object Type: Report
System: The UNT Digital Library
Scaling up the 454 Titanium Library Construction and Pooling of Barcoded Libraries (open access)

Scaling up the 454 Titanium Library Construction and Pooling of Barcoded Libraries

We have been developing a high throughput 454 library construction process at the Joint Genome Institute to meet the needs of de novo sequencing a large number of microbial and eukaryote genomes, EST, and metagenome projects. We have been focusing efforts in three areas: (1) modifying the current process to allow the construction of 454 standard libraries on a 96-well format; (2) developing a robotic platform to perform the 454 library construction; and (3) designing molecular barcodes to allow pooling and sorting of many different samples. In the development of a high throughput process to scale up the number of libraries by adapting the process to a 96-well plate format, the key process change involves the replacement of gel electrophoresis for size selection with Solid Phase Reversible Immobilization (SPRI) beads. Although the standard deviation of the insert sizes increases, the overall quality sequence and distribution of the reads in the genome has not changed. The manual process of constructing 454 shotgun libraries on 96-well plates is a time-consuming, labor-intensive, and ergonomically hazardous process; we have been experimenting to program a BioMek robot to perform the library construction. This will not only enable library construction to be completed in a single …
Date: March 23, 2009
Creator: Phung, Wilson; Hack, Christopher; Shapiro, Harris; Lucas, Susan & Cheng, Jan-Fang
Object Type: Report
System: The UNT Digital Library
Imaging of magnetic DW injection processed in patterened Ni80Fe20 structures (open access)

Imaging of magnetic DW injection processed in patterened Ni80Fe20 structures

Magnetization reversal in patterned ferromagnetic nanowires usually occurs via domain wall (DW) nucleation and propagation from one end (or both ends) of the wire which can be significantly reduced by a large, magnetically soft pad on one of the wire ends. These 'nucleation pads' reverse at lower fields than an isolated nanowire and introduce a DW to the wire from the wire end attached to the pad. Once a critical 'injection' field is reached, the DW sweeps through the wire, reversing its magnetization. Nucleation pads are frequently used as part of nanowire devices and experimental structures. Magnetic-field-driven shift register memory can include an injection pad to write data while those attached to nanowire spiral turn sensors act as both a source and sink of domain walls. Both of these devices use two-dimensional wire circuits and therefore require the use of orthogonal in-plane magnetic fields to drive domain walls through wires of different orientations. These bi-axial fields can significantly alter the fields at which DW injection occurs and control the number of different injection modes. We have used magnetic transmission soft X-ray microscopy (M-TXM) [6] providing 25nm spatial resolution to image the evolution of magnetization configurations in patterned 24nm thick Ni{sub …
Date: March 23, 2009
Creator: Bryan, M. T.; Basu, S.; Fry, P. W.; Schrefl, T.; Gibbs, M.R.J.; Allwood, D. A. et al.
Object Type: Article
System: The UNT Digital Library
SALTSTONE 2QCY08 TCLP RESULTS (open access)

SALTSTONE 2QCY08 TCLP RESULTS

A Saltstone waste form was prepared in the Savannah River National Laboratory from a Tank 50H sample and Z-Area premix material for the second quarter of calendar year 2008 (2QCY08). After the prescribed 28 day cure, samples of the saltstone were collected, and the waste form was shown to meet the South Carolina Hazardous Waste Management Regulations (SCHWMR) R.61-79.261.24 and R.61-79.268.48(a) requirements for a nonhazardous waste form with respect to RCRA metals and underlying hazardous constituents. These analyses met all quality assurance specifications of USEPA SW-846. The Saltstone Production Facility (SPF) receives waste from Tank 50H for treatment. In the second quarter of the 2008 calendar year (2QCY08), Tank 50 accepted transfers of approximately 21 kgal from the Effluent Treatment Project (ETP) waste, approximately 3 kgal from Tank 710--the H-Canyon General Purpose Evaporator, and approximately 23 kgal form the Modular Caustic Side Solvent Extraction Unit (MCU) Decontaminated Salt Solution Hold Tank (DSS-HT). The Saltstone Grout Sampling plan provides the South Carolina Department of Health and Environmental Control (SCDHEC) with the chemical and physical characterization strategy for the salt solution which is to be disposed of in the Z-Area Solid Waste Landfill (ISWLF). During operation, samples were collected from Tank 50H …
Date: March 23, 2009
Creator: Cozzi, A
Object Type: Report
System: The UNT Digital Library
Mathematical and Statistical Opportunities in Cyber Security (open access)

Mathematical and Statistical Opportunities in Cyber Security

The role of mathematics in a complex system such as the Internet has yet to be deeply explored. In this paper, we summarize some of the important and pressing problems in cyber security from the viewpoint of open science environments. We start by posing the question 'What fundamental problems exist within cyber security research that can be helped by advanced mathematics and statistics'? Our first and most important assumption is that access to real-world data is necessary to understand large and complex systems like the Internet. Our second assumption is that many proposed cyber security solutions could critically damage both the openness and the productivity of scientific research. After examining a range of cyber security problems, we come to the conclusion that the field of cyber security poses a rich set of new and exciting research opportunities for the mathematical and statistical sciences.
Date: March 23, 2009
Creator: Meza, Juan; Campbell, Scott & Bailey, David
Object Type: Report
System: The UNT Digital Library
Development of Functionally Graded Materials for Manufacturing Tools and Dies and Industrial Processing Equipment (open access)

Development of Functionally Graded Materials for Manufacturing Tools and Dies and Industrial Processing Equipment

Hot forming processes such as forging, die casting and glass forming require tooling that is subjected to high temperatures during the manufacturing of components. Current tooling is adversely affected by prolonged exposure at high temperatures. Initial studies were conducted to determine the root cause of tool failures in a number of applications. Results show that tool failures vary and depend on the operating environment under which they are used. Major root cause failures include (1) thermal softening, (2) fatigue and (3) tool erosion, all of which are affected by process boundary conditions such as lubrication, cooling, process speed, etc. While thermal management is a key to addressing tooling failures, it was clear that new tooling materials with superior high temperature strength could provide improved manufacturing efficiencies. These efficiencies are based on the use of functionally graded materials (FGM), a new subset of hybrid tools with customizable properties that can be fabricated using advanced powder metallurgy manufacturing technologies. Modeling studies of the various hot forming processes helped identify the effect of key variables such as stress, temperature and cooling rate and aid in the selection of tooling materials for specific applications. To address the problem of high temperature strength, several advanced …
Date: March 23, 2009
Creator: Lherbier, Louis, W.; Novotnak, David, J.; Herling, Darrell, R. & Sears, James, W.
Object Type: Report
System: The UNT Digital Library
GAMMA-PULSE-HEIGHT EVALUATION OF A USA SAVANNAH RIVER SITE BURIAL GROUND SPECIAL CONFIGURATION WASTE ITEM (open access)

GAMMA-PULSE-HEIGHT EVALUATION OF A USA SAVANNAH RIVER SITE BURIAL GROUND SPECIAL CONFIGURATION WASTE ITEM

The Savannah River Site (SRS) Burial Ground had a container labeled as Box 33 for which they had no reliable solid waste stream designation. The container consisted of an outer box of dimensions 48-inch x 46-inch x 66-inch and an inner box that contained high density and high radiation dose material. From the outer box Radiation Control measured an extremity dose rate of 22 mrem/h. With the lid removed from the outer box, the maximum dose rate measured from the inner box was 100 mrem/h extremity and 80 mrem/h whole body. From the outer box the material was sufficiently high in density that the Solid Waste Management operators were unable to obtain a Co-60 radiograph of the contents. Solid Waste Management requested that the Analytical Development Section of Savannah River National Laboratory perform a {gamma}-ray assay of the item to evaluate the radioactive content and possibly to designate a solid waste stream. This paper contains the results of three models used to analyze the measured {gamma}-ray data acquired in an unusual configuration.
Date: March 23, 2009
Creator: Dewberry, R.; Sigg, R. & Salaymeh, S.
Object Type: Article
System: The UNT Digital Library
Massive Supergravity and Deconstruction (open access)

Massive Supergravity and Deconstruction

We present a simple superfield Lagrangian for massive supergravity. It comprises the minimal supergravity Lagrangian with interactions as well as mass terms for the metric superfield and the chiral compensator. This is the natural generalization of the Fierz-Pauli Lagrangian for massive gravity which comprises mass terms for the metric and its trace. We show that the on-shell bosonic and fermionic fields are degenerate and have the appropriate spins: 2, 3/2, 3/2 and 1. We then study this interacting Lagrangian using goldstone superfields. We find that achiral multiplet of goldstones gets a kinetic term through mixing, just as the scalar goldstone does in the non-supersymmetric case. This produces Planck scale (Mpl) interactions with matter and all the discontinuities and unitarity bounds associated with massive gravity. In particular, the scale of strong coupling is (Mpl m^4)^1/5, where m is the multiplet's mass. Next, we consider applications of massive supergravity to deconstruction. We estimate various quantum effects which generate non-local operators in theory space. As an example, we show that the single massive supergravity multiplet in a 2-site model can serve the function of an extra dimension in anomaly mediation.
Date: March 23, 2004
Creator: Gregoire, Thomas; Schwartz, Matthew D. & Shadmi, Yael
Object Type: Article
System: The UNT Digital Library
Research Opportunities in High Energy Density Laboratory Plasmas on the NDCX-II Facility (open access)

Research Opportunities in High Energy Density Laboratory Plasmas on the NDCX-II Facility

Intense beams of heavy ions offer a very attractive tool for fundamental research in high energy density physics and inertial fusion energy science. These applications build on the significant recent advances in the generation, compression and focusing of intense heavy ion beams in the presence of a neutralizing background plasma. Such beams can provide uniform volumetric heating of the target during a time-scale shorter than the hydrodynamic response time, thereby enabling a significant suite of experiments that will elucidate the underlying physics of dense, strongly-coupled plasma states, which have been heretofore poorly understood and inadequately diagnosed, particularly in the warm dense matter regime. The innovations, fundamental knowledge, and experimental capabilities developed in this basic research program is also expected to provide new research opportunities to study the physics of directly-driven ion targets, which can dramatically reduce the size of heavy ion beam drivers for inertial fusion energy applications. Experiments examining the behavior of thin target foils heated to the warm dense matter regime began at the Lawrence Berkeley National Laboratory in 2008, using the Neutralized Drift Compression Experiment - I (NDCX-I) facility, and its associated target chamber and diagnostics. The upgrade of this facility, called NDCX-II, will enable an exciting …
Date: March 23, 2009
Creator: Barnard, John; Cohen, Ron; Friedman, Alex; Grote, Dave; Lund, Steven; Sharp, Bill et al.
Object Type: Report
System: The UNT Digital Library
Manufacture of Alumina-Forming Austenitic Stainless Steel Alloys by Conventional Casting and Hot-Working Methods (open access)

Manufacture of Alumina-Forming Austenitic Stainless Steel Alloys by Conventional Casting and Hot-Working Methods

Oak Ridge National Laboratory (ORNL) and Carpenter Technology Corporation (CarTech) participated in an in-kind cost share cooperative research and development agreement (CRADA) effort under the auspices of the Energy Efficiency and Renewable Energy (EERE) Technology Maturation program to explore the feasibility for scale up of developmental ORNL alumina-forming austenitic (AFA) stainless steels by conventional casting and rolling techniques. CarTech successfully vacuum melted 30lb heats of four AFA alloy compositions in the range of Fe-(20-25)Ni-(12-14)Cr-(3-4)Al-(1-2.5)Nb wt.% base. Conventional hot/cold rolling was used to produce 0.5-inch thick plate and 0.1-inch thick sheet product. ORNL subsequently successfully rolled the 0.1-inch sheet to 4 mil thick foil. Long-term oxidation studies of the plate form material were initiated at 650, 700, and 800 C in air with 10 volume percent water vapor. Preliminary results indicated that the alloys exhibit comparable (good) oxidation resistance to ORNL laboratory scale AFA alloy arc casting previously evaluated. The sheet and foil material will be used in ongoing evaluation efforts for oxidation and creep resistance under related CRADAs with two gas turbine engine manufacturers. This work will be directed to evaluation of AFA alloys for use in gas turbine recuperators to permit higher-temperature operating conditions for improved efficiencies and reduced …
Date: March 23, 2009
Creator: Brady, M.P.; Yamamoto, Y. & Magee, J.H. (Carpenter Technol. Corp.)
Object Type: Report
System: The UNT Digital Library
Structural health monitoring of wind turbine blades : SE 265 Final Project. (open access)

Structural health monitoring of wind turbine blades : SE 265 Final Project.

ACME Wind Turbine Corporation has contacted our dynamic analysis firm regarding structural health monitoring of their wind turbine blades. ACME has had several failures in previous years. Examples are shown in Figure 1. These failures have resulted in economic loss for the company due to down time of the turbines (lost revenue) and repair costs. Blade failures can occur in several modes, which may depend on the type of construction and load history. Cracking and delamination are some typical modes of blade failure. ACME warranties its turbines and wishes to decrease the number of blade failures they have to repair and replace. The company wishes to implement a real time structural health monitoring system in order to better understand when blade replacement is necessary. Because of warranty costs incurred to date, ACME is interested in either changing the warranty period for the blades in question or predicting imminent failure before it occurs. ACME's current practice is to increase the number of physical inspections when blades are approaching the end of their fatigue lives. Implementation of an in situ monitoring system would eliminate or greatly reduce the need for such physical inspections. Another benefit of such a monitoring system is that …
Date: March 23, 2006
Creator: Barkley, W. C. (Walter C.); Jacobs, Laura D.; Rutherford, A. C. (Amanda C.) & Puckett, Anthony
Object Type: Report
System: The UNT Digital Library
Monitoring plan for Everest, Kansas. (open access)

Monitoring plan for Everest, Kansas.

This transmittal is a response to your request of January 22, 2009, for a letter work plan outlining a program of annual groundwater and surface water monitoring at Everest, Kansas. Once yearly, they propose to conduct surface water sampling at the 5 locations shown in Figure 1 and groundwater sampling in the 16 wells identified in Figure 2. The wells will be sampled according to the low-flow procedure. The next sampling event is planned for April 2009. The surface water and groundwater samples collected will be preserved, shipped, and analyzed for volatile organic compounds as in previous work at Everest. Results will be reported to the KDHE. This monitoring program will continue until identified plume conditions at the site indicate a technical justification to change the monitoring program.
Date: March 23, 2009
Creator: LaFreniere, L. M.
Object Type: Report
System: The UNT Digital Library
Prediction and observation of tin and silver plasmas with index of refraction greater than one in the soft X-ray range (open access)

Prediction and observation of tin and silver plasmas with index of refraction greater than one in the soft X-ray range

None
Date: March 23, 2006
Creator: Filevich, J.; Grava, J.; Purvis, M.; Marconi, M. C.; Rocca, J. J.; Nilsen, J. et al.
Object Type: Article
System: The UNT Digital Library