THERMAL CONDUCTIVITY AND OTHER PROPERTIES OF CEMENTITIOUS GROUTS (open access)

THERMAL CONDUCTIVITY AND OTHER PROPERTIES OF CEMENTITIOUS GROUTS

The thermal conductivity and other properties cementitious grouts have been investigated in order to determine suitability of these materials for grouting vertical boreholes used with geothermal heat pumps. The roles of mix variables such as water/cement ratio, sand/cement ratio and superplasticizer dosage were measured. In addition to thermal conductivity, the cementitious grouts were also tested for bleeding, permeability, bond to HDPE pipe, shrinkage, coefficient of thermal expansion, exotherm, durability and environmental impact. This paper summarizes the results for selected grout mixes. Relatively high thermal conductivities were obtained and this leads to reduction in predicted bore length and installation costs. Improvements in shrinkage resistance and bonding were achieved.
Date: May 1, 1998
Creator: ALLAN,M.
Object Type: Article
System: The UNT Digital Library
Metal waste forms from treatment of EBR-II spent fuel. (open access)

Metal waste forms from treatment of EBR-II spent fuel.

Demonstration of Argonne National Laboratory's electrometallurgical treatment of spent nuclear fuel is currently being conducted on irradiated, metallic driver fuel and blanket fuel elements from the Experimental Breeder Reactor-II (EBR-II) in Idaho. The residual metallic material from the electrometallurgical treatment process is consolidated into an ingot, the metal waste form (MWF), by employing an induction furnace in a hot cell. Scanning electron microscopy (SEM) and chemical analyses have been performed on irradiated cladding hulls from the driver fuel, and on samples from the alloy ingots. This paper presents the microstructures of the radioactive ingots and compares them with observations on simulated waste forms prepared using non-irradiated material. These simulated waste forms have the baseline composition of stainless steel - 15 wt % zirconium (SS-15Zr). Additions of noble metal elements, which serve as surrogates for fission products, and actinides are made to that baseline composition. The partitioning of noble metal and actinide elements into alloy phases and the role of zirconium for incorporating these elements is discussed in this paper.
Date: May 18, 1998
Creator: Abraham, D. P.
Object Type: Article
System: The UNT Digital Library
Drying behavior of K-East canister sludge (open access)

Drying behavior of K-East canister sludge

A series of tests were conducted by Pacific Northwest National Laboratory to evaluate the drying behavior of sludge taken from the Hanford K-East Basin storage canisters. Some of the components of K-Basin sludge, such as oxides of uranium and its hydrates, could be associated with the spent nuclear fuel that will ultimately be loaded into Multi-Canister Overpacks (MCOs) and transferred to interim dry storage on the Hanford Site. The materials sealed in the MCOs must be compatible with the storage facility safety basis and the design accident analyses. Understanding the drying behavior of hydrates that may be formed by the reaction of uranium oxides (corrosion products) and water will help ensure these criteria are addressed. Drying measurements of sludge samples collected from K-East Basin canisters showed the water content (physically plus chemically bound) to range between 5 wt% and 75 wt%. Uranium oxide hydrates, the main source of gaseous products that can pressurize the MCOs during storage, constituted about 3 wt% to 15 wt% of the total water content of the initial weight. Most of the physically bound water was assumed to be released from the samples at ambient temperature when the system was pumped down to vacuum conditions of …
Date: May 1, 1998
Creator: Abrefah, J.; Buchanan, H. C. & Marschman, S. C.
Object Type: Report
System: The UNT Digital Library
Examination of the surface coating removed from K-East Basin fuel elements (open access)

Examination of the surface coating removed from K-East Basin fuel elements

This report provides the results of studies conducted on coatings discovered on the surfaces of some N-Reactor spent nuclear fuel (SNF) elements stored at the Hanford K-East Basin. These elements had been removed from the canisters and visually examined in-basin during FY 1996 as part of a series of characterization tests. The characterization tests are being performed to support the Integrated Process Strategy developed to package, dry, transport, and store the SNF in an interim storage facility on the Hanford site. Samples of coating materials were removed from K-East canister elements 2350E and 2540E, which had been sent, along with nine other elements, to the Postirradiation Testing Laboratory (327 Building) for further characterization following the in-basin examinations. These coating samples were evaluated by Pacific Northwest National Laboratory using various analytical methods. This report is part of the overall studies to determine the drying behavior of corrosion products associated with the K-Basin fuel elements. Altogether, five samples of coating materials were analyzed. These analyses suggest that hydration of the coating materials could be an additional source of moisture in the Multi-Canister Overpacks being used to contain the fuel for storage.
Date: May 1, 1998
Creator: Abrefah, J.; Marschman, S.C. & Jenson, E.D.
Object Type: Report
System: The UNT Digital Library
Microfluidic systems for electrochemical and biological studies (open access)

Microfluidic systems for electrochemical and biological studies

Microfluidic devices with microelectrodes have the potential to enable studies of phenomena at size scales where behavior may be dominated by different mechanisms than at macroscales. Through our work developing microfluidic devices for dielectrophoretic separation and sensing of cells and particles, we have fabricated devices from which general or more specialized research devices may be derived. Fluid channels from 80 {micro}m wide X 20 {micro}m deep to 1 mm wide to 200 {micro}m deep have been fabricated in glass, with lithographically patterned electrodes from 10 to 80 {micro}m wide on one or both sides on the channels and over topographies tens of microns in heights. the devices are designed to easily interface to electronic and fluidic interconnect packages that permit reuse of devices, rather than one-time use, crude glue-based methods. Such devices may be useful for many applications of interest to the electrochemical and biological community.
Date: May 1998
Creator: Ackler, H.
Object Type: Article
System: The UNT Digital Library
U.S. Department of Energy National Center of Excellence for Metals Recycle (open access)

U.S. Department of Energy National Center of Excellence for Metals Recycle

The US Department of Energy (DOE) National Center of Excellence for Metals Recycle has recently been established. The vision of this new program is to develop a DOE culture that promotes pollution prevention by considering the recycle and reuse of metal as the first and primary disposition option and burial as a last option. The Center of Excellence takes the approach that unrestricted release of metal is the first priority because it is the most cost-effective disposition pathway. Where this is not appropriate, restricted release, beneficial reuse, and stockpile of ingots are considered. Current recycling activities include the sale of 40,000 tons of scrap metal from the East Tennessee Technology Park (formerly K-25 Plant) K-770 scrap yard, K-1064 surplus equipment and machinery, 7,000 PCB-contaminated drums, 12,000 tons of metal from the Y-l2 scrap yard, and 1,000 metal pallets. In addition, the Center of Excellence is developing a toolbox for project teams that will contain a number of specific tools to facilitate metals recycle. This Internet-based toolbox will include primers, computer programs, and case studies designed to help sites to perform life cycle analysis, perform ALARA (As Low As is Reasonably Achievable) analysis for radiation exposures, provide pollution prevention information and …
Date: May 1, 1998
Creator: Adams, V.; Bennett, M. & Bishop, L.
Object Type: Article
System: The UNT Digital Library
Boron-enhanced diffusion of boron from ultralow-energy boron implantation (open access)

Boron-enhanced diffusion of boron from ultralow-energy boron implantation

The authors have investigated the diffusion enhancement mechanism of BED (boron enhanced diffusion), wherein the boron diffusivity is enhanced three to four times over the equilibrium diffusivity at 1,050 C in the proximity of a silicon layer containing a high boron concentration. It is shown that BED is associated with the formation of a fine-grain polycrystalline silicon boride phase within an initially amorphous Si layer having a high B concentration. For 0.5 keV B{sup +}, the threshold implantation dose which leads to BED lies between 3 {times} 10{sup 14} and of 1 {times} 10{sup 15}/cm{sup {minus}2}. Formation of the shallowest possible junctions by 0.5 keV B{sup +} requires that the implant dose be kept lower than this threshold.
Date: May 3, 1998
Creator: Agarwal, A.; Eaglesham, D.J.; Gossmann, H.J.; Pelaz, L.; Herner, S.B.; Jacobson, D.C. et al.
Object Type: Report
System: The UNT Digital Library
Naturalness and supersymmetry (open access)

Naturalness and supersymmetry

In this thesis, the author argues that the supersymmetric Standard Model, while avoiding the fine tuning in electroweak symmetry breaking, requires unnaturalness/fine tuning in some (other) sector of the theory. For example, Baryon and Lepton number violating operators are allowed which lead to proton decay and flavor changing neutral currents. He studies some of the constraints from the latter in this thesis. He has to impose an R-parity for the theory to be both natural and viable. In the absence of flavor symmetries, the supersymmetry breaking masses for the squarks and sleptons lead to too large flavor changing neutral currents. He shows that two of the solutions to this problem, gauge mediation of supersymmetry breaking and making the scalars of the first two generations heavier than a few TeV, reintroduce fine tuning in electroweak symmetry breaking. He also constructs a model of low energy gauge mediation with a non-minimal messenger sector which improves the fine tuning and also generates required Higgs mass terms. He shows that this model can be derived from a Grand Unified Theory despite the non-minimal spectrum.
Date: May 1, 1998
Creator: Agashe, K.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Amorphous Diamond Flat Panel Displays - Final Report of ER-LTR CRADA project with SI Diamond Technology (open access)

Amorphous Diamond Flat Panel Displays - Final Report of ER-LTR CRADA project with SI Diamond Technology

The objective of this project was to determine why diamond-based films are unusually efficient electron emitters (field emission cathodes) at room temperature. Efficient cathodes based on diamond are being developed by SI Diamond Technology (SIDT) as components for bright, sunlight-readable, flat panel displays. When the project started, it was known that only a small fraction (<1%) of the cathode area is active in electron emission and that the emission sites themselves are sub-micron in size. The critical challenge of this project was to develop new microcharacterization methods capable of examining known emission sites. The research team used a combination of cathode emission imaging (developed at SIDT), micro-Raman spectroscopy (LBNL), and electron microscopy and spectroscopy (National Center for Electron Microscopy, LBNL) to examine the properties of known emission sites. The most significant accomplishment of the project was the development at LBNL of a very high resolution scanning probe that, for the first time, measured simultaneously the topography and electrical characteristics of single emission sites. The increased understanding of the emission mechanism helped SIDT to develop a new cathode material,''nano-diamond,'' which they have incorporated into their Field Emission Picture Element (FEPix) product. SIDT is developing large-format flat panel displays based on these …
Date: May 8, 1998
Creator: Ager, Joel W., III
Object Type: Report
System: The UNT Digital Library
Raman Spectroscopy Characterization of amorphous carbon coatings for computer hard disks (open access)

Raman Spectroscopy Characterization of amorphous carbon coatings for computer hard disks

Amorphous carbon films are used as protective coatings on magnetic media to protect the magnetic layer from wear and abrasion caused by the read/write head during hard disk drive start-up and operation. A key requirement in increasing the storage capacity and reliability of hard-disk drives is improving the performance of these coatings. This cooperative agreement used optical characterization techniques developed at LBNL to study thin-film hard disk media produced by Seagate Technology, major US hard drive manufacturer. The chief scientific goal was relating quantitatively the results of the optical characterization to the underlying chemical structure of the overcoat. In a collaboration with Seagate, LBNL, and Cambridge University, optical and electron-based characterization were used to evaluate the chemical structure of overcoats. The sp3 fraction of the sputtered amorphous carbon films was measured quantitatively for the first time and related to the optical spectroscopy results. This work and other selected aspects of the research performed under the agreement were presented at technical meetings and published in the open literature. The chief technical goal was designing manufacturing processes for the protective carbon overcoat for use in new generations of Seagate disk drives. To this end, joint research carried out under this agreement enabled …
Date: May 7, 1998
Creator: Ager, Joel W., III
Object Type: Report
System: The UNT Digital Library
Development, field testing of a laser instrument for the measurement of sediment reference concentration in the MARGINS Program. Final report (open access)

Development, field testing of a laser instrument for the measurement of sediment reference concentration in the MARGINS Program. Final report

A small grant was added to an ongoing Navy program to extend the scope of ongoing work by development of a new laser instrument. The instrument, MSCAT (Miniature Scattering and Transmissometry) uses small angle scattering to obtain the needed multi-parameter information for measurement of particle size distribution and number density. During the short course of the grant, the instrument was built and tested in a field experiment off the coast of North Carolina. Useful data were obtained, and these have been presented at the Fall Meeting of the American Geophysical Union in 1994.
Date: May 22, 1998
Creator: Agrawal, Yogesh C.
Object Type: Report
System: The UNT Digital Library
Di-jet production by double pomeron exchange in CDF (open access)

Di-jet production by double pomeron exchange in CDF

We have studied events with a high-x{sub F} antiproton and two central jets with E{sub T} > 7 GeV in CDF, in p{anti p} collisions at {radical}s = 1800 GeV. We find an excess of events with a rapidity gap at least 3.5 units wide in the proton direction, which we interpret as di-jet production in double pomeron exchange events.
Date: May 1, 1998
Creator: Albrow, M.G.
Object Type: Article
System: The UNT Digital Library
Highest energy phenomena in the universe (open access)

Highest energy phenomena in the universe

One of the most enduring and frustrating mysteries in astrophysics is the nature of the cosmic gamma-ray burst (GRB). GRB` s were first reported in the 1970` s, and since then have been observed from over a dozen different satellites. Two recently launched satellites have revolutionized this field. One, the most sensitive, is known as the Compton Gamma-Ray Observatory (CGRO). This orbiting observatory carries an experiment known as the Burst and Transient Source Experiment (BATSE), which was intended to help elucidate the nature and origin of GRB` s. The other is the Italian-Dutch satellite Beppo-SAX, which is substantially less sensitive than BATSE, but can provide greatly superior positional accuracy for the GRBs it detects. The purpose of this LDRD project was to maximize the combined return of these satellites and two ground-based programs (MACHO [Massive Compact Halo Objects] and LOTIS [Livermore Optical Transient Imaging System]), which LLNL largely controls. We have been successful in designing and implementing real-time response systems, and have successfully responded to GRBs with the MACHO Telescope System.
Date: May 13, 1998
Creator: Alcock, C. R., LLNL
Object Type: Report
System: The UNT Digital Library
Dynamic effects of linkage joints in electrostatic microengines (open access)

Dynamic effects of linkage joints in electrostatic microengines

The electrostatic micro-engine is one of the major actuators used in MEMS applications. To ensure this MEMS actuator is operated in a fashion that will produce peak performance and long life, the system dynamics must be fully understood. One of the major trade-offs in the micro-engine design is the use of either pin or flexure joints. This paper will develop the equations of motion for flexure-jointed and pin-jointed surface micromachined microengines. An analytical mechanics approach will be used to derive the equations of motion and the appropriate equations of constraint. The effect of the flexure joints on the drive signals of the micro engine is experimentally shown to be significant during static tests.
Date: May 1, 1998
Creator: Allen, J. J.; Miller, S. L. & LaVigne, G. F.
Object Type: Article
System: The UNT Digital Library
A comparison of regulatory impacts to real target impacts (open access)

A comparison of regulatory impacts to real target impacts

The purpose of this paper is to discuss the relative severity of regulatory impacts onto an essentially rigid target to impacts at higher velocities onto real targets. For impacts onto the essentially rigid target all of the kinetic energy of the package is absorbed by deformation of the package. For impacts onto real targets the kinetic energy is absorbed by deformation of the target as well as by deformation of the package. The amount of kinetic energy absorbed by the target does not increase the severity of the impact.
Date: May 1, 1998
Creator: Ammerman, D.J.
Object Type: Article
System: The UNT Digital Library
Testing and analysis to determine the shell thickness required to prevent puncture (open access)

Testing and analysis to determine the shell thickness required to prevent puncture

Type B radioactive material packages are required to withstand a hypothetical puncture accident of a free fall from a height of one meter onto a 15 cm diameter mild steel puncture probe. For many packages it is desirable to have this accident event not result in puncture or tearing of the outer shell of the package. The wall thickness necessary to prevent this has historically been determined by test or the use of empirical relations. This technique generally results in overly conservative designs, but the degree of conservatism is uncertain. The use of modem finite element codes to determine package response to puncture accidents can result in designs that are both safe and economical. The work reported in this paper is aimed at developing a method to analytically determine the wall thickness required to prevent puncture. For designers and regulators to have confidence in this analytical method, however, it must be benchmarked against test results. A series of tests has been conducted with differing shell thicknesses, shell materials of mild steel and stainless steel, and shell backing materials of lead, foam, and air. The results of these tests have been compared with pre-test analytical predictions of the response obtained from …
Date: May 1, 1998
Creator: Ammerman, D.J.; Radloff, H.D. & Eifert, E.J.
Object Type: Article
System: The UNT Digital Library
Tank characterization report for single-shell tank 241-BX-111 (open access)

Tank characterization report for single-shell tank 241-BX-111

This document summarizes the information on the historical uses, present status, and the sampling and analysis results of waste, stored in Tank 241-BX-111. This report supports the requirements of the Tri-Party Agreement Milestone M-44-ISB.
Date: May 5, 1998
Creator: Anantatmula, R. P.
Object Type: Report
System: The UNT Digital Library
Glass Formulation Development for the Vitrification of Oak Ridge Tank Waste (open access)

Glass Formulation Development for the Vitrification of Oak Ridge Tank Waste

Crystalline silicotitanate (CST) is a highly specific ion exchange material for cesium. In particular, CST has been successfully demonstrated with both simulants and actual supernates from Savannah River and Hanford tank wastes. As a disposal option, vitrification of the cesium-loaded CST coupled with High-Level Waste (HLW) has been proposed. However, the CST sorbent contains significant quantities of titanium which historically have been difficult to incorporate into the glass structure. Therefore, nonradioactive tests using CST coupled with simulated HLW were performed to develop a glass formulation that would be both processable and durable. The results of the simulated crucible melts were verified using radioactive waste and cesium-loaded CST. This paper will detail the results of the formulation efforts.
Date: May 1, 1998
Creator: Andrews, M. K. & Workman, P. J.
Object Type: Article
System: The UNT Digital Library
Hydroacoustic propagation grids for the CTBT knowledge databaes BBN technical memorandum W1303 (open access)

Hydroacoustic propagation grids for the CTBT knowledge databaes BBN technical memorandum W1303

The Hydroacoustic Coverage Assessment Model (HydroCAM) has been used to develop components of the hydroacoustic knowledge database required by operational monitoring systems, particularly the US National Data Center (NDC). The database, which consists of travel time, amplitude correction and travel time standard deviation grids, is planned to support source location, discrimination and estimation functions of the monitoring network. The grids will also be used under the current BBN subcontract to support an analysis of the performance of the International Monitoring System (IMS) and national sensor systems. This report describes the format and contents of the hydroacoustic knowledgebase grids, and the procedures and model parameters used to generate these grids. Comparisons between the knowledge grids, measured data and other modeled results are presented to illustrate the strengths and weaknesses of the current approach. A recommended approach for augmenting the knowledge database with a database of expected spectral/waveform characteristics is provided in the final section of the report.
Date: May 1, 1998
Creator: Angell, J.
Object Type: Report
System: The UNT Digital Library
EFFECTS OF MINERALOGY AND CATION-EXCHANGE CAPACITY ON LIGHIUM SORPTION TO YUCCA MOUNTAIN TUFFS. (open access)

EFFECTS OF MINERALOGY AND CATION-EXCHANGE CAPACITY ON LIGHIUM SORPTION TO YUCCA MOUNTAIN TUFFS.

None
Date: May 7, 1998
Creator: Anghel, I.; Turnin, H. J.; Reimus, P. W. & Carey, J. W.
Object Type: Report
System: The UNT Digital Library
Predicting New Hampshire Indoor Radon Concentrations from geologic information and other covariates (open access)

Predicting New Hampshire Indoor Radon Concentrations from geologic information and other covariates

Generalized geologic province information and data on house construction were used to predict indoor radon concentrations in New Hampshire (NH). A mixed-effects regression model was used to predict the geometric mean (GM) short-term radon concentrations in 259 NH towns. Bayesian methods were used to avoid over-fitting and to minimize the effects of small sample variation within towns. Data from a random survey of short-term radon measurements, individual residence building characteristics, along with geologic unit information, and average surface radium concentration by town, were variables used in the model. Predicted town GM short-term indoor radon concentrations for detached houses with usable basements range from 34 Bq/m{sup 3} (1 pCi/l) to 558 Bq/m{sup 3} (15 pCi/l), with uncertainties of about 30%. A geologic province consisting of glacial deposits and marine sediments, was associated with significantly elevated radon levels, after adjustment for radium concentration, and building type. Validation and interpretation of results are discussed.
Date: May 1, 1998
Creator: Apte, M. G.; Price, P. N.; Nero, A. V. & Revzan, K. L.
Object Type: Article
System: The UNT Digital Library
Transport of subsurface bacteria in porous media. Final report (open access)

Transport of subsurface bacteria in porous media. Final report

The aims of our project have not changed significantly since the original proposal. Our primary goals were to support field experiments by screening strains of bacteria to find favorable transport characteristics among field isolates and to estimate collision efficiencies for those bacteria in typical Oyster site sediments. The data we obtained were disseminated to other members of the subprogram. For example, Tim Ginn of PNL incorporated our results into his field model; Aaron Mills used our work for comparison purposes; and John Wilson used our results to determine if there is a correlation between facies type and cell adhesion. Copies of all information were also sent to Mary DeFlaun of Envirogen for incorporation into the Sample Tables. In addition to the originally proposed work, we performed longer column studies, examining the effects of aluminum, iron, and water chemistry on bacterial transport, and beginning to understand the role of electrostatic interactions as determinants of biocolloid/collector affinity.
Date: May 1, 1998
Creator: Arnold, Robert G.; Baygents, James C. & Ogden, Kimberly L.
Object Type: Report
System: The UNT Digital Library
Human events reference for ATHEANA (HERA) database description and preliminary user`s manual (open access)

Human events reference for ATHEANA (HERA) database description and preliminary user`s manual

The Technique for Human Error Analysis (ATHEANA) is a newly developed human reliability analysis (HRA) methodology that aims to facilitate better representation and integration of human performance into probabilistic risk assessment (PRA) modeling and quantification by analyzing risk-significant operating experience in the context of existing behavioral science models. The fundamental premise of ATHEANA is that error-forcing contexts (EFCs), which refer to combinations of equipment/material conditions and performance shaping factors (PSFs), set up or create the conditions under which unsafe actions (UAs) can occur. Because ATHEANA relies heavily on the analysis of operational events that have already occurred as a mechanism for generating creative thinking about possible EFCs, a database, called the Human Events Reference for ATHEANA (HERA), has been developed to support the methodology. This report documents the initial development efforts for HERA.
Date: May 27, 1998
Creator: Auflick, J.L.; Hahn, H.A. & Pond, D.J.
Object Type: Report
System: The UNT Digital Library
The Development of Chemically Vapor Deposited Mullite Coatings for the Corrosion Protection of SiC (open access)

The Development of Chemically Vapor Deposited Mullite Coatings for the Corrosion Protection of SiC

Crystalline mullite coatings have been chemically vapor deposited onto SiC substrates to enhance the corrosion and oxidation resistance of the substrate. Current research has been divided into three distinct areas: (1) Development of the deposition processing conditions for increased control over coating`s growth rate, microstructure, and morphology; (2) Analysis of the coating`s crystal structure and stability; (3) The corrosion resistance of the CVD mullite coating on SiC.
Date: May 1, 1998
Creator: Auger, M.; Hou, P.; Sengupta, A.; Basu, S. & Sarin, V.
Object Type: Report
System: The UNT Digital Library