A Bayesian Approach to Surface X-ray Diffraction (open access)

A Bayesian Approach to Surface X-ray Diffraction

We report on the development of an iterative method to directly invert surface x-ray diffraction (SXRD) data and thereby provide a map of electron density in the near-surface region of a solid. We have termed this method PARADIGM, which stands for Phase and Amplitude Recovery And Diffraction Image Generation Method. Significant advances in the PARADIGM theory were made during the grant period, and experimental milestones have also been achieved. The two components of the research program worked in concert, each spurring progress in the other. The method works by iteratively recovering the phases of surface scattering factors. Initially, random phases are assigned to the structure factors. After subtracting off the known bulk component, a Fourier transform converts these factors into an estimate of the real-space electron density map. This map is subjected to a support constraint, which holds that the electron density may only be non-zero near the solid surface. The modified electron density is then subjected to an inverse Fourier transform, and the bulk contributions are added back in. This renders an improved estimate of the phases of the surface structure factors. A constraint in reciprocal space is then applied, namely, the amplitudes of the scattering factors are set …
Date: November 17, 2006
Creator: Lyman, Paul F. & Saldin, Dilano K.
Object Type: Report
System: The UNT Digital Library
Chemical Analysis Of Beryllium Shells (open access)

Chemical Analysis Of Beryllium Shells

There is a need to understand the level of high-Z impurities in Beryllium shells prepared by sputter coating. The Ignition Point Design Requirements state the following: ''Except for allowed ingredients, as listed in the ablator composition entries, the ablator material in all layers shall contain sufficiently low impurity levels that the sum over all impurities of atom fraction*Z{sup 2} shall be less than or equal to 0.2''. This is a tight specification that requires careful materials analysis. Early in the first quarter of FY06, we undertook a study of Be shell impurities via ICP-MS{sup 2} and determined that the impurity levels in the sputtered shells are very close to the specification.
Date: November 17, 2005
Creator: Gunther, J & Cook, R
Object Type: Report
System: The UNT Digital Library
Advances in Shock Timing Experiments on the National Ignition Facility (open access)

Advances in Shock Timing Experiments on the National Ignition Facility

None
Date: November 17, 2013
Creator: Robey, H. F.; Celliers, P. M.; Moody, J. D.; Sater, J.; Parham, T.; Kozioziemski, B. et al.
Object Type: Article
System: The UNT Digital Library
Internal Technical Report, Safety Analysis Report 5 MW(e) Raft River Research and Development Plant (open access)

Internal Technical Report, Safety Analysis Report 5 MW(e) Raft River Research and Development Plant

The Raft River Geothermal Site is located in Southern Idaho's Raft River Valley, southwest of Malta, Idaho, in Cassia County. EG and G idaho, Inc., is the DOE's prime contractor for development of the Raft River geothermal field. Contract work has been progressing for several years towards creating a fully integrated utilization of geothermal water. Developmental progress has resulted in the drilling of seven major DOE wells. Four are producing geothermal water from reservoir temperatures measured to approximately 149 C (approximately 300 F). Closed-in well head pressures range from 69 to 102 kPa (100 to 175 psi). Two wells are scheduled for geothermal cold 60 C (140 F) water reinjection. The prime development effort is for a power plant designed to generate electricity using the heat from the geothermal hot water. The plant is designated as the ''5 MW(e) Raft River Research and Development Plant'' project. General site management assigned to EG and G has resulted in planning and development of many parts of the 5 MW program. Support and development activities have included: (1) engineering design, procurement, and construction support; (2) fluid supply and injection facilities, their study, and control; (3) development and installation of transfer piping systems for …
Date: November 17, 1981
Creator: Brown, E.S.; Homer, G.B.; Shaber, C.R. & Thurow, T.L.
Object Type: Report
System: The UNT Digital Library
Aluminide Coatings for Power-Generation Applications (open access)

Aluminide Coatings for Power-Generation Applications

Aluminide coatings are of interest for many high temperature applications because of the possibility of improving the oxidation of structural alloys by forming a protective external alumina scale. In order to develop a comprehensive lifetime evaluation approach for aluminide coatings used in fossil energy systems, some of the important issues have been addressed in this report for aluminide coatings on Fe-based alloys (Task I) and on Ni-based alloys (Task II). In Task I, the oxidation behavior of iron aluminide coatings synthesized by chemical vapor deposition (CVD) was studied in air + 10vol.% H{sub 2}O in the temperature range of 700-800 C and the interdiffusion behavior between the coating and substrate was investigated in air at 500-800 C. Commercial ferritic (Fe-9Cr-1Mo) and type 304L (Fe-18Cr-9Ni, nominally) austenitic stainless steels were used as the substrates. For the oxidation study, the as-deposited coating consisted of a thin (<5 {micro}m), Al-rich outer layer above a thicker (30-50 {micro}m), lower Al inner layer. The specimens were cycled to 1000 1-h cycles at 700 C and 500 1-h cycles at 800 C, respectively. The CVD coating specimens showed excellent performance in the water vapor environment at both temperatures, while the uncoated alloys were severely attacked. These …
Date: November 17, 2003
Creator: Zhang, Y
Object Type: Report
System: The UNT Digital Library
Spectral Predictors (open access)

Spectral Predictors

Many scientific, imaging, and geospatial applications produce large high-precision scalar fields sampled on a regular grid. Lossless compression of such data is commonly done using predictive coding, in which weighted combinations of previously coded samples known to both encoder and decoder are used to predict subsequent nearby samples. In hierarchical, incremental, or selective transmission, the spatial pattern of the known neighbors is often irregular and varies from one sample to the next, which precludes prediction based on a single stencil and fixed set of weights. To handle such situations and make the best use of available neighboring samples, we propose a local spectral predictor that offers optimal prediction by tailoring the weights to each configuration of known nearby samples. These weights may be precomputed and stored in a small lookup table. We show that predictive coding using our spectral predictor improves compression for various sources of high-precision data.
Date: November 17, 2006
Creator: Ibarria, L; Lindstrom, P & Rossignac, J
Object Type: Article
System: The UNT Digital Library
Status and Monitoring of Natural and Supplemented Chinook Salmon in Johnson Creek, Idaho, 2006-2007 Annual Report. (open access)

Status and Monitoring of Natural and Supplemented Chinook Salmon in Johnson Creek, Idaho, 2006-2007 Annual Report.

The Nez Perce Tribe Johnson Creek Artificial Propagation Enhancement Project (JCAPE) has conducted juvenile and adult monitoring and evaluation studies for its 10th consecutive year. Completion of adult and juvenile Chinook salmon studies were conducted for the purpose of evaluating a small-scale production initiative designed to increase the survival of a weak but recoverable spawning aggregate of summer Chinook salmon Oncorhynchus tshawytscha. The JCAPE program evaluates the life cycle of natural origin (NOR) and hatchery origin (HOR) supplementation fish to quantify the key performance measures: abundance, survival-productivity, distribution, genetics, life history, habitat, and in-hatchery metrics. Operation of a picket style weir and intensive multiple spawning ground surveys were completed to monitor adult Chinook salmon and a rotary screw trap was used to monitor migrating juvenile Chinook salmon in Johnson Creek. In 2007, spawning ground surveys were conducted on all available spawning habitat in Johnson Creek and one of its tributaries. A total of 63 redds were observed in the index reach and 11 redds for all other reaches for a combined count of 74 redds. Utilization of carcass recovery surveys and adult captures at an adult picket weir yielded a total estimated adult escapement to Johnson Creek of 438 Chinook …
Date: November 17, 2008
Creator: Rabe, Craig D. & Nelson, Douglas D.
Object Type: Report
System: The UNT Digital Library
Decay Tables for the Natural Radioactive Series III. Thorium (4n) Series (open access)

Decay Tables for the Natural Radioactive Series III. Thorium (4n) Series

The third in this series of reports presents tables dealing with the growth and decay of members of the thorium family of naturally occurring radioisotopes. The general equations and approximations used in computing these tables are the same as those presented in Part I of the series.
Date: November 17, 1952
Creator: Kirby, H. W.
Object Type: Report
System: The UNT Digital Library
Metabolic analysis of the soil microbe Dechloromonas aromatica str. RCB: indications of a surprisingly complex life-style and cryptic anaerobic pathways for aromatic degradation (open access)

Metabolic analysis of the soil microbe Dechloromonas aromatica str. RCB: indications of a surprisingly complex life-style and cryptic anaerobic pathways for aromatic degradation

Initial interest in Dechloromonas aromatica strain RCB arose from its ability to anaerobically degrade benzene. It is also able to reduce perchlorate and oxidize chlorobenzoate, toluene, and xylene, creating interest in using this organism for bioremediation. Little physiological data has been published for this microbe. It is considered to be a free-living organism. The a priori prediction that the D. aromatica genome would contain previously characterized 'central' enzymes involved in anaerobic aromatic degradation proved to be false, suggesting the presence of novel anaerobic aromatic degradation pathways in this species. These missing pathways include the benzyl succinyl synthase (bssABC) genes (responsible for formate addition to toluene) and the central benzoylCoA pathway for monoaromatics. In depth analyses using existing TIGRfam, COG, and InterPro models, and the creation of de novo HMM models, indicate a highly complex lifestyle with a large number of environmental sensors and signaling pathways, including a relatively large number of GGDEF domain signal receptors and multiple quorum sensors. A number of proteins indicate interactions with an as yet unknown host, as indicated by the presence of predicted cell host remodeling enzymes, effector enzymes, hemolysin-like proteins, adhesins, NO reductase, and both type III and type VI secretory complexes. Evidence of …
Date: November 17, 2008
Creator: Salinero, Kennan Kellaris; Keller, Keith; Feil, William S.; Feil, Helene; Trong, Stephan; Di Bartolo, Genevieve et al.
Object Type: Article
System: The UNT Digital Library
Undulator Hall Air Temperature Fault Scenarios (open access)

Undulator Hall Air Temperature Fault Scenarios

Recent experience indicates that the LCLS undulator segments must not, at any time following tuning, be allowed to change temperature by more than about {+-}2.5 C or the magnetic center will irreversibly shift outside of acceptable tolerances. This vulnerability raises a concern that under fault conditions the ambient temperature in the Undulator Hall might go outside of the safe range and potentially could require removal and retuning of all the segments. In this note we estimate changes that can be expected in the Undulator Hall air temperature for three fault scenarios: (1) System-wide power failure; (2) Heating Ventilation and Air Conditioning (HVAC) system shutdown; and (3) HVAC system temperature regulation fault. We find that for either a system-wide power failure or an HVAC system shutdown (with the technical equipment left on), the short-term temperature changes of the air would be modest due to the ability of the walls and floor to act as a heat ballast. No action would be needed to protect the undulator system in the event of a system-wide power failure. Some action to adjust the heat balance, in the case of the HVAC power failure with the equipment left on, might be desirable but is not …
Date: November 17, 2010
Creator: Sevilla, J. & Welch, J.
Object Type: Report
System: The UNT Digital Library
Response to"Analysis of the Treatment, by the U.S. Department of Energy, of the FEP Hydrothermal Activity in the Yucca Mountain Performance Assessment" by Yuri Dublyansky (open access)

Response to"Analysis of the Treatment, by the U.S. Department of Energy, of the FEP Hydrothermal Activity in the Yucca Mountain Performance Assessment" by Yuri Dublyansky

This paper presents a rebuttal to Dublyansky (2007), which misrepresents technical issues associated with hydrothermal activity at the proposed Yucca Mountain nuclear waste repository and their importance to the long-term performance of the repository. In this paper, questions associated with hydrothermal activity are reviewed and the justification for exclusion of hydrothermal activity from performance assessment is presented. The hypothesis that hydrothermal upwelling into the present-day unsaturated zone has occurred at Yucca Mountain is refuted by the unambiguous evidence that secondary minerals and fluid inclusions in the unsaturated zone formed in an unsaturated environment from downward percolating meteoric waters. The thermal history at Yucca Mountain, inferred from fluid inclusion and isotopic data, is explained in terms of the tectonic extensional environment and associated silicic magmatism. The waning of tectonic extension over millions of years has led to the present-day heat flux in the Yucca Mountain region that is below average for the Great Basin. The long time scales of tectonic processes are such that any effects of a resumption of extension or silicic magmatism on hydrothermal activity at Yucca Mountain over the 10,000-year regulatory period would be negligible. The conclusion that hydrothermal activity was incorrectly excluded from performance assessment as asserted …
Date: November 17, 2008
Creator: Houseworth, J.E. & Hardin, E.
Object Type: Report
System: The UNT Digital Library
Code-to-Code Benchmarking of the Porflow and Goldsim Contaminant Transport Models Using a Simple 1-D Domain - 11191 (open access)

Code-to-Code Benchmarking of the Porflow and Goldsim Contaminant Transport Models Using a Simple 1-D Domain - 11191

An investigation was conducted to compare and evaluate contaminant transport results of two model codes, GoldSim and Porflow, using a simple 1-D string of elements in each code. Model domains were constructed to be identical with respect to cell numbers and dimensions, matrix material, flow boundary and saturation conditions. One of the codes, GoldSim, does not simulate advective movement of water; therefore the water flux term was specified as a boundary condition. In the other code, Porflow, a steady-state flow field was computed and contaminant transport was simulated within that flow-field. The comparisons were made solely in terms of the ability of each code to perform contaminant transport. The purpose of the investigation was to establish a basis for, and to validate follow-on work that was conducted in which a 1-D GoldSim model developed by abstracting information from Porflow 2-D and 3-D unsaturated and saturated zone models and then benchmarked to produce equivalent contaminant transport results. A handful of contaminants were selected for the code-to-code comparison simulations, including a non-sorbing tracer and several long- and short-lived radionuclides exhibiting both non-sorbing to strongly-sorbing characteristics with respect to the matrix material, including several requiring the simulation of in-growth of daughter radionuclides. The …
Date: November 17, 2010
Creator: Hiergesell, R. & Taylor, G.
Object Type: Article
System: The UNT Digital Library
Operating the LCLS Gas Attenuator and Gas Detector System with Apertures of 6mm Diameter (open access)

Operating the LCLS Gas Attenuator and Gas Detector System with Apertures of 6mm Diameter

The possibility of increasing the apertures of the LCLS gas attenuator/gas detector system is considered. It is shown that increase of the apertures from 3 to 6 mm, together with 4-fold reduction of the operation pressure does not adversely affect the vacuum conditions upstream or downstream. No change of the pump speed and the lengths of the differential pumping cells is required. One minor modification is the use of 1.5 cm long tubular apertures in the end cells of the differential pumping system. Reduction of the pressure does not affect performance of the gas attenuator/gas detector system at the FEL energies below, roughly, 2 keV. Some minor performance degradation occurs at higher energies.
Date: November 17, 2010
Creator: Ryutov, D. D.; Bionta, R. M.; Hau-Riege, S. P.; Kishiyama, K. I.; Roeben, M. D.; Shen, S. et al.
Object Type: Report
System: The UNT Digital Library
MEETING VII-BEVATRON RESEARCH CONFERENCE--COUNTING EQUIPMENT FOR THE BEVATRON (open access)

MEETING VII-BEVATRON RESEARCH CONFERENCE--COUNTING EQUIPMENT FOR THE BEVATRON

This discussion will review the results of a survey of present plans for the Bevatron counting equipment. Proposed counting facilities, tentative specifications for desired counting equipment, a view of past counting techniques, and some of the later associated circuits will be considered.
Date: November 17, 1953
Creator: Wiegand, Clyde.
Object Type: Report
System: The UNT Digital Library
REPORT ON RESULTS OF IMPACT TESTS PERFORMED ON Ti 75A AND ON IODIDE TITANIUM SPECIMENS (open access)

REPORT ON RESULTS OF IMPACT TESTS PERFORMED ON Ti 75A AND ON IODIDE TITANIUM SPECIMENS

None
Date: November 17, 1952
Creator: Fretague, W J
Object Type: Report
System: The UNT Digital Library
Undulator Transportation Test Results (open access)

Undulator Transportation Test Results

A test was performed to determine whether transporting and handling the undulators makes any changes to their properties. This note documents the test. No significant changes to the test undulator were observed. After the LCLS undulators are tuned and fiducialized in the Magnetic Measurement Facility (MMF), they must be transported to storage buildings and transported to the tunnel. It has been established that the undulators are sensitive to temperature. We wish to know whether the undulators are also sensitive to the vibrations and shocks of transportation. To study this issue, we performed a test in which an undulator was measured in the MMF, transported to the tunnel, brought back to the MMF, and re-measured. This note documents the test and the results.
Date: November 17, 2010
Creator: Wolf, Zachary; Horton, Nick; Kharakh, David; Levashov, Yurii; Nuhn, Heinz-Dieter; Poling, Ben et al.
Object Type: Report
System: The UNT Digital Library
In situ Removal of Actinides and Strontium from High Level Waste Tanks, Tea Bag versus Adsorption Column (open access)

In situ Removal of Actinides and Strontium from High Level Waste Tanks, Tea Bag versus Adsorption Column

Initiatives are underway at the Savannah River Site (SRS) to accelerate the disposition of the supernate and salt portions of the waste in the SRS High Level Waste (HLW) tank farm system. Significant savings in processing time and overall cost could be achieved by in situ treatment of waste supernate or dissolved salt inside a tank farm waste tank. For treatment of actinides and strontium in waste, the baseline method is sorption onto monosodium titanate (MST), an engineered powder with mean particle size of approximately 10 microns. In a separate study at the Savannah River National Laboratory (SRNL), engineered forms of MST were developed and compared on a small (250-mL) scale in batch tests. In the current study, a promising form of engineered MST was tested under two conditions: a traditional ion exchange (or adsorption) column and a porous, flow through device called a tea bag, immersed in solution. Both tests used the same amount of engineered MST to treat 10 L of simulated waste solution containing plutonium and strontium.
Date: November 17, 2004
Creator: MARK, CROWDER
Object Type: Report
System: The UNT Digital Library
A SEA FLOOR GRAVITY SURVEY OF THE SLEIPNER FIELD TO MONITOR CO2 MIGRATION (open access)

A SEA FLOOR GRAVITY SURVEY OF THE SLEIPNER FIELD TO MONITOR CO2 MIGRATION

Since 1996, excess CO{sub 2} from the Sleipner natural gas field has been sequestered and injected underground into a porous saline aquifer 1000 m below the seafloor. In 2002, we carried out a high precision micro-gravity survey on the seafloor in order to monitor the injected CO{sub 2}. A repeatability of 5 {micro}Gal in the station averages was observed. This is considerably better than pre-survey expectations. These data will serve as the baseline for time-lapse gravity monitoring of the Sleipner CO{sub 2} injection site. A three-week trip to Statoil Research Centre in Trondheim, Norway, was made in the summer of 2003. This visit consisted of gathering data and collaborating with scientists working on the Sleipner project. The trip ended with a presentation of the seafloor gravity results to date at a SACS2 (Saline Aquifer CO{sub 2} Storage 2) meeting. This meeting provided the perfect opportunity to meet and gather information from the world's experts on the Sleipner project.
Date: November 17, 2003
Creator: Zuberge, Mark; Nooner, Scott & Sasagawa, Glenn
Object Type: Report
System: The UNT Digital Library
Photoelectrochemical Hydrogen Production - Final Report (open access)

Photoelectrochemical Hydrogen Production - Final Report

The scope of this photoelectrochemical hydrogen research project is defined by multijunction photoelectrode concepts for solar-powered water splitting, with the goal of efficient, stable, and economic operation. From an initial selection of several planar photoelectrode designs, the Hybrid Photoelectrode (HPE) has been identified as the most promising candidate technology. This photoelectrode consists of a photoelectrochemical (PEC) junction and a solid-state photovoltaic (PV) junction. Immersed in aqueous electrolyte and exposed to sunlight, these two junctions provide the necessary voltage to split water into hydrogen and oxygen gas. The efficiency of the conversion process is determined by the performance of the PEC- and the PV-junctions and on their spectral match. Based on their stability and cost effectiveness, iron oxide (Fe2O3) and tungsten oxide (WO3) films have been studied and developed as candidate semiconductor materials for the PEC junction (photoanode). High-temperature synthesis methods, as reported for some high-performance metal oxides, have been found incompatible with multijunction device fabrication. A low-temperature reactive sputtering process has been developed instead. In the parameter space investigated so far, the optoelectronic properties of WO3 films were superior to those of Fe2O3 films, which showed high recombination of photo-generated carriers. For the PV-junction, amorphous-silicon-based multijunction devices have been studied. …
Date: November 17, 2004
Creator: Miller, E. L.; Marsen, B.; Paluselli, D. & Rocheleau, R.
Object Type: Report
System: The UNT Digital Library
Lack of Support for the Association Between GAD2 Polymorphisms and Severe Human Obesity (open access)

Lack of Support for the Association Between GAD2 Polymorphisms and Severe Human Obesity

Demonstration of association between common genetic variants and chronic human diseases such as obesity could have profound implications for the prediction, prevention and treatment of these conditions. Unequivocal proof of such an association, however, requires adherence to established methodological guidelines, which include independent replication of initial positive findings. Recently, single nucleotide polymorphisms (SNPs) within GAD2 were found to be associated with class III obesity (BMI > 40 kg/m2) in 188 families (612 individuals) segregating the condition and a case-control study of 575 cases and 646 lean controls. Functional data supporting a pathophysiological role for one of the SNPs (-243A>G) were also presented. In the present study, we attempted to replicate this association in larger groups of subjects, and to extend the functional studies of the -243A>G SNP. In 2,327 subjects comprising 692 German nuclear families with severe, early-onset obesity, we found no evidence for a relationship between the three GAD2 SNPs and obesity, whether SNPs were studied individually or as haplotypes. In two independent case-control studies (a total of 680 class III obesity cases and 1,186 lean controls), there was no significant relationship between the -243A>G SNP and obesity (odds ratio (OR) = 0.99, 95% CI 0.83 - 1.18,in the …
Date: November 17, 2004
Creator: Swarbrick, Michael M.; Waldenmaier, Bjorn; Pennacchio, Len A.; Lind,Denise L.; Cavazos, Martha M.; Geller, Frank et al.
Object Type: Article
System: The UNT Digital Library
MEMBRANE SYSTEM FOR RECOVERY OF VOLATILE ORGANIC COMPOUNDS FROM REMEDIATION OFF-GASES (open access)

MEMBRANE SYSTEM FOR RECOVERY OF VOLATILE ORGANIC COMPOUNDS FROM REMEDIATION OFF-GASES

In situ vacuum extraction, air or steam sparging, and vitrification are widely used to remediate soil contaminated with volatile organic compounds (VOCs). All of these processes produce a VOC-laden air stream from which the VOC must be removed before the air can be discharged or recycled to the generating process. Treatment of these off-gases is often a major portion of the cost of the remediation project. Currently, carbon adsorption and catalytic incineration are the most common methods of treating these gas streams. Membrane Technology and Research, Inc. (MTR) proposed an alternative treatment technology based on selective membranes that separate the organic components from the gas stream, producing a VOC-free air stream. This technology can be applied to off-gases produced by various remediation activities and the systems can be skid-mounted and automated for easy transportation and unattended operation. The target performance for the membrane systems is to produce clean air (less than 10 ppmv VOC) for discharge or recycle, dischargeable water (less than 1 ppmw VOC), and a concentrated liquid VOC phase. This report contains the results obtained during Phase II of a two-phase project. In Phase I, laboratory experiments were carried out to demonstrate the feasibility of the proposed approach. …
Date: November 17, 2003
Creator: Wijmans, J.G.
Object Type: Report
System: The UNT Digital Library
Engineering Monosodium Titanate for Adsorption Column Processes (open access)

Engineering Monosodium Titanate for Adsorption Column Processes

Monosodium titanate (MST) is an inorganic adsorbent powder that effectively removes strontium, plutonium, neptunium, and other trace elements from alkaline high-level waste (HLW) supernate. This work tested one commercial titanate and four general methods to engineer MST into particles large enough to use in adsorption columns. The most successful of the engineered products selected from batch contact and chemical stability testing succeeded in treating 2900 bed volumes (BV) of simulated salt waste containing dissolved plutonium and strontium. There was no detectable strontium breakthrough and only 6 per cent plutonium breakthrough--well within the processing goal--at the end of the demonstration which operated at 5.3 BV/hour. Additional column tests at nominally 15 BV/hr demonstrated similar removal performance. Batch testing of adsorbents used both actual Savannah River Site (SRS) tank supernate as well as simulated salt solutions spiked with strontium, neptunium, and plutonium. In tank waste tests, internal gelation beads produced by the Oak Ridge National Laboratory (ORNL) demonstrated a batch distribution coefficient of 35,000 +/- 4,000 mL/g for plutonium at a phase ratio of 1970 mL/g. In the same batch the sorbent demonstrated a batch distribution coefficient of 99,000 +/- 7,500 mL/g for strontium. These results indicate that this material should be …
Date: November 17, 2004
Creator: NASH, CHARLES
Object Type: Article
System: The UNT Digital Library
Role of Transport Phenomena in the Evolution of Geometry, Composition and Structure (open access)

Role of Transport Phenomena in the Evolution of Geometry, Composition and Structure

Abstract Fusion welding is used extensively in industries that support the nation's energy supply, defense, infrastructure, and standard of living. Safety and reliability of the welded joints are affected by their geometry, composition and structure. This report provides an account of the significant advances made in quantitative understanding of the geometry, composition and various aspects of the weldment structure with financial support from DOE/BES. In particular, this report provides an account of the research conducted under the grant DE-FG02-84ER45158 in this important area and lists all the publications that document the details of the technical accomplishments that resulted from the work. Investigations of heat transfer, fluid flow and alloying element vaporization during laser welding resulted in a new technique for the determination of the peak temperature in the weld pool and provided a new method to estimate weld metal composition. Studies on the interfacial phenomena in fusion welding resulted in quantitative understanding of the interrelationship between the weld metal composition and geometry and provided new knowledge as to when the surface active elements would affect the weldment geometry and when these elements would have no effect on the geometry. Partitioning of oxygen nitrogen and hydrogen between the welding environment and …
Date: November 17, 2005
Creator: DebRoy, Tarasankar
Object Type: Text
System: The UNT Digital Library
THE BC CRIBS & TRENCHES GEOPHYSICAL CHARACTERIZATION PROJECT ONE STEP FORWARD IN HANFORDS CLEANUP PROCESS (open access)

THE BC CRIBS & TRENCHES GEOPHYSICAL CHARACTERIZATION PROJECT ONE STEP FORWARD IN HANFORDS CLEANUP PROCESS

A geophysical characterization project was conducted at the BC Cribs and Trenches Area, located south of 200 East at the Hanford Site. The area consists of 26 waste disposal trenches and cribs, which received approximately 30 million gallons of liquid waste from the uranium recovery process and the ferrocyanide processes associated with wastes generated by reprocessing nuclear fuel. Waste discharges to BC Cribs contributed perhaps the largest liquid fraction of contaminants to the ground in the 200 Areas. The site also includes possibly the largest inventory of Tc-99 ever disposed to the soil at Hanford with an estimated quantity of 400 Ci. Other waste constituents included high volumes of nitrate and U-238. The geophysical characterization at the 50-acre site primarily included high resolution resistivity (HRR). The resistivity technique is a non-invasive method by which electrical resistivity data are collected along linear transects, and data are presented as continuous profiles of subsurface electrical properties. The transects ranged in size from about 400-700 meters and provided information down to depths of 60 meters. The site was characterized by a network of 51 HRR lines with a total of approximately 19.7 line kilometers of data collected parallel and perpendicular to the trenches and …
Date: November 17, 2005
Creator: BENECKE, M.W.
Object Type: Report
System: The UNT Digital Library