Magnetic anisotropy and its microstructural origin in epitaxially grown SmCo thin films. (open access)

Magnetic anisotropy and its microstructural origin in epitaxially grown SmCo thin films.

Microstructural features and magnetic behavior of epitaxially grown SmCo thin films with very high in-plane anisotropy are presented. Transmission electron microscopy was used to characterize the microstructure while magnetic measurements were performed using dc and SQUID magnetometers. Two substrate orientations were studied, i.e., MgO(100)/Cr(100)/SmCo(11{bar 2}0) and MgO(110)/Cr(211)/SmCo(1{bar 1}00). In the former, the SmCo(11{bar 2}0) film shows a bicrystalline microstructure, whereas in the latter, a uniaxial one is observed. Both microstructure consist of grains with a mixture of SmCo{sub 3} , Sm{sub 2}Co{sub 7} and SmCo{sub 3} polytypoids. A deviation from the c-axes was observed in the in-plane anisotropy of the SmCo(11{bar 2}0) thin film. A strong exchange interaction between the grains would, in principle, explain the observed deviation. On the other hand, both SmCo(11{bar 2}0) and (1{bar 1}00) thin films show very high coercivity values with pinning-type characteristics. Possible coercivity mechanisms related to intergranular exchange interactions and local variation in magnetocrystalline anisotropy constants are discussed.
Date: April 15, 1998
Creator: Benaissa, M.
Object Type: Article
System: The UNT Digital Library
Concentration of uranium and plutonium in unsaturated spent fuel tests. (open access)

Concentration of uranium and plutonium in unsaturated spent fuel tests.

Commercial spent fuel is being tested under oxidizing conditions at 90 C in drip tests with simulated groundwater to evaluate its long-term performance in a potential repository at Yucca Mountain [1-4]. The tests allow us to monitor the dissolution behavior of the spent fuel matrix and the release rates of individual radionuclides. This paper reports the U and Pu concentrations in the leachates of drip tests during 3.7 years of reaction. Changes in these concentrations are correlated with changes in the measured pH and the appearance of alteration products on the fuel surface. Although there is little thermodynamic information at 90 C for either uranyl or plutonium compounds, some data are available at 25 C [5-8]. The literature data for the U and Pu solubilities of U and Pu compounds were compared to the U and Pu concentrations in the leachates. We also compare Wilson's [9] U and Pu concentrations in semi-static tests at 85 C on spent fuel with our results.
Date: April 15, 1998
Creator: Finn, P. A.
Object Type: Article
System: The UNT Digital Library
Improved Oil Recovery in Fluvial Dominated Deltaic Reservoirs of Kansas - Near-Term (open access)

Improved Oil Recovery in Fluvial Dominated Deltaic Reservoirs of Kansas - Near-Term

The objective of this study is to study waterflood problems of the type found in Morrow sandstone. The major tasks undertaken are reservoir characterization and the development of a reservoir database; volumetric analysis to evaluate production performance; reservoir modeling; identification of operational problems; identification of unrecovered mobile oil and estimation of recovery factors; and identification of the most efficient and economical recovery process.
Date: April 15, 1998
Creator: Walton, A.; McCune, D.; Green, D. W.; Willhite, G. P.; Watney, L.; Reynolds, R. et al.
Object Type: Report
System: The UNT Digital Library
A sparse superlinearly convergent SQP with applications to two-dimensional shape optimization. (open access)

A sparse superlinearly convergent SQP with applications to two-dimensional shape optimization.

Discretization of optimal shape design problems leads to very large nonlinear optimization problems. For attaining maximum computational efficiency, a sequential quadratic programming (SQP) algorithm should achieve superlinear convergence while preserving sparsity and convexity of the resulting quadratic programs. Most classical SQP approaches violate at least one of the requirements. We show that, for a very large class of optimization problems, one can design SQP algorithms that satisfy all these three requirements. The improvements in computational efficiency are demonstrated for a cam design problem.
Date: April 15, 1998
Creator: Anitescu, M.
Object Type: Article
System: The UNT Digital Library
Quarterly Technical Progress Report - West Hackberry Tertiary Project (open access)

Quarterly Technical Progress Report - West Hackberry Tertiary Project

The West Hackberry Tertiary Project is a field test of the concept that air injection can generate tertiary oil recovery through the Double Displacement Process is the gas displacement of a water invaded oil column for the purpose of recovering tertiary oil through gravity discharge. The novel aspect of this project is the use of air as the injection fluid.
Date: April 15, 1998
Creator: Yannimaras, Demetrois & Gillham, Travis
Object Type: Report
System: The UNT Digital Library
A procedure for the automatic estimation of mixed layer height. (open access)

A procedure for the automatic estimation of mixed layer height.

The daytime mixed layer results from mechanical and thermal turbulence processes driven by differences in air-surface temperature and moisture. As such, the height of the mixed layer (z{sub i}) is a measure of the effectiveness of energy transfer from the sun to the earth's surface and, in turn, to the lower atmosphere (Stun, 1989). Maximum daytime values for z{sub i} in the region of the Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) vary from less than 100 m in cloudy, moist, calm, stable conditions to nearly 3 km in clear, dry, unstable conditions. The principal characteristic of the mixed layer is that scalar quantities such as moisture and temperature are mixed throughout. Thus, z{sub i} becomes one of the principal scaling parameters used to describe the structure of the lower planetary boundary layer. Normally, a stable layer (a potential temperature inversion) at the top of the mixed layer interfaces between processes in the lower atmosphere and in the free atmosphere above. The strength of this inversion limits the rate of growth of z{sub i} with time and the vertical transfer of energy and moisture. When and if z{sub i} reaches the condensation level, clouds can form; hence, cloud …
Date: April 15, 1998
Creator: Coulter, R. L.
Object Type: Article
System: The UNT Digital Library
Phase 1 Final Report for In-Situ Tritium Beta Detector (open access)

Phase 1 Final Report for In-Situ Tritium Beta Detector

The objectives of this three-phase project were to design, develop, and demonstrate a monitoring system capable of detecting and quantifying tritium in situ in ground and surface waters, and in water from effluent lines prior to discharge into public waterways. The tritium detection system design is based on measurement of the low energy beta radiation from the radioactive decay of tritium using a special form of scintillating optical fiber directly in contact with the water to be measured. The system consists of the immersible sensor module containing the optical fiber, and an electronics package, connected by an umbilical cable. The system can be permanently installed for routine water monitoring in wells or process or effluent lines, or can be moved from one location to another for survey use. The electronics will read out tritium activity directly in units of pico Curies per liter, with straightforward calibration. In Phase 1 of the project, we characterized the sensitivity of fluor-doped plastic optical fiber to tritium beta radiation. In addition, we characterized the performance of photomultiplier tubes needed for the system. In parallel with this work, we defined the functional requirements, target specifications, and system configuration for an in situ tritium beta detector …
Date: April 15, 1998
Creator: Berthold, J. W. & Jeffers, L. A.
Object Type: Report
System: The UNT Digital Library
Safety evaluation for packaging (onsite) product removal can containers (open access)

Safety evaluation for packaging (onsite) product removal can containers

Six Product Removal (PR) Cans and Containers are located within the Plutonium Finishing Plant. Each can is expected to contain a maximum of 3 g of residual radioactive material, consisting mainly of plutonium isotopes. The PR Can Containers were previously authorized by HNF-SD-TP-SEP-064, Rev. 0 (Boettger 1997), for the interarea transport of up to 3 g of plutonium. The purpose of this safety evaluation for packaging is to allow the transport of six PR Cans with their Containers from the Plutonium Finishing Plant to the 233 S Evaporator Facility. This safety evaluation for packaging is authorized for use until April 29, 1999, or until the shipment is made, whichever happens first.
Date: April 15, 1998
Creator: Burnside, M.E.
Object Type: Report
System: The UNT Digital Library
Solid waste information and tracking system client-server conversion project management plan (open access)

Solid waste information and tracking system client-server conversion project management plan

This Project Management Plan is the lead planning document governing the proposed conversion of the Solid Waste Information and Tracking System (SWITS) to a client-server architecture. This plan presents the content specified by American National Standards Institute (ANSI)/Institute of Electrical and Electronics Engineers (IEEE) standards for software development, with additional information categories deemed to be necessary to describe the conversion fully. This plan is a living document that will be reviewed on a periodic basis and revised when necessary to reflect changes in baseline design concepts and schedules. This PMP describes the background, planning and management of the SWITS conversion. It does not constitute a statement of product requirements. Requirements and specification documentation needed for the SWITS conversion will be released as supporting documents.
Date: April 15, 1998
Creator: May, D.L.
Object Type: Report
System: The UNT Digital Library
Micropower impulse radar technology and applications (open access)

Micropower impulse radar technology and applications

The LLNL-developed Micropower Impulse Radar (MIR) technology has quickly gone from laboratory concept to embedded circuitry in numerous government and commercial systems in the last few years[l]. The main ideas behind MIR, invented by T. McEwan in the Laser Program, are the generation and detection systems for extremely low- power ultra-wideband pulses in the gigaHertz regime using low-cost components. These ideas, coupled with new antenna systems, timing and radio-frequency (RF) circuitry, computer interfaces, and signal processing, have provided the catalyst for a new generation of compact radar systems. Over the past several years we have concentrated on a number of applications of MIR which address a number of remote-sensing applications relevant to emerging programs in defense, transportation, medical, and environmental research. Some of the past commercial successes have been widely publicized [2] and are only now starting to become available for market. Over 30 patents have been filed and over 15 licenses have been signed on various aspects of the MIR technology. In addition, higher performance systems are under development for specific laboratory programs and government reimbursables. The MIR is an ultra- wideband, range-gated radar system that provides the enabling hardware technology used in the research areas mentioned above. It …
Date: April 15, 1998
Creator: Mast, J., LLNL
Object Type: Report
System: The UNT Digital Library
Systems engineering management and implementation plan for Project W-464, immobilized high-level waste storage (open access)

Systems engineering management and implementation plan for Project W-464, immobilized high-level waste storage

The Systems Engineering Management and Implementation Plan (SEMIP) for TWRS Project W-46 describes the project implementation of the Tank Waste Remediation System Systems Engineering Management Plan. (TWRS SEMP), Rev. 1. The SEMIP outlines systems engineering (SE) products and processes to be used by the project for technical baseline development. A formal graded approach is used to determine the products necessary for requirements, design, and operational baseline completion. SE management processes are defined, and roles and responsibilities for management processes and major technical baseline elements are documented.
Date: April 15, 1998
Creator: Wecks, M.D.
Object Type: Report
System: The UNT Digital Library
Design review report: 200 East upgrades for Project W-314, tank farm restoration and safe operations (open access)

Design review report: 200 East upgrades for Project W-314, tank farm restoration and safe operations

This Design Review Report (DRR) documents the contractor design verification methodology and records associated with project W-314`s 200 East (200E) Upgrades design package. The DRR includes the documented comments and their respective dispositions for this design. Acceptance of the comment dispositions and closure of the review comments is indicated by the signatures of the participating reviewers. Project W-314 is a project within the Tank Waste Remediation System (TWRS) Tank Waste Retrieval Program. This project provides capital upgrades for the existing Hanford tank farm waste transfer, instrumentation, ventilation, and electrical infrastructure systems. To support established TWRS programmatic objectives, the project is organized into two distinct phases. The initial focus of the project (i.e., Phase 1) is on waste transfer system upgrades needed to support the TWRS Privatization waste feed delivery system. Phase 2 of the project will provide upgrades to support resolution of regulatory compliance issues, improve tank infrastructure reliability, and reduce overall plant operating/maintenance costs. Within Phase 1 of the W-314 project, the waste transfer system upgrades are further broken down into six major packages which align with the project`s work breakdown structure. Each of these six sub-elements includes the design, procurement, and construction activities necessary to accomplish the specific …
Date: April 15, 1998
Creator: Boes, K.A.
Object Type: Report
System: The UNT Digital Library
Energy and waste reduction in the wood fiber and fuel industry utilizing a long wave length catalytic infrared drying system. Progress report No.4, January 1--March 31, 1998 (open access)

Energy and waste reduction in the wood fiber and fuel industry utilizing a long wave length catalytic infrared drying system. Progress report No.4, January 1--March 31, 1998

During the past quarter significant headway was made on the project. The design and fabrication of the materials handling system by the subcontractor, Cat-Tech Industries, was completed in late January and was shipped in February to Catalytic Industrial System (CIS) Kansas facility. Unfortunately a part shipped directly from the manufacturer, for mating in Kansas to the unit, was determined to be the wrong size and nearly a month was lost in the process of ordering and receiving the correct parts. In early March the system was ready for agitation testing and performed perfectly. Design of the air circulation system was completed in late March and fabrication and installation of that element is expected to be completed this week (April 15--22). The insulation panels have been designed and ordered and are expected to be on site and ready for installation the last week of April. In a series of conference phone calls, it was decided to increase the amount of infrared energy input in Zone 1 (the first one-third of the 30 foot unit) of the dryer. These zones are presently being redesigned and fabricated and will likely be installed by the 10th of May. Product testing is expected to commence …
Date: April 15, 1998
Creator: Davis, R.
Object Type: Report
System: The UNT Digital Library
HPGe compton suppression using pulse shape analysis (open access)

HPGe compton suppression using pulse shape analysis

We present a new technique for High Purity Germanium (HPGe) Compton suppression using pulse shape analysis (PSA). The novel aspect of our approach involves a complete unfolding of the charge pulse shape into a discrete sum of component y-ray interactions. Using the energy and position information obtained from such an unfolding, an algorithm is then applied which favorably rejects Compton escape events. The advantage of the current PSA approach, as compared with other recent approaches, is the potential to reject not only single-site escape events, but also multiple site escape events. Here we discuss the details of our algorithm, and present experimental results from a real-time implementation on a 5 cm X 5 cm HPGe. An experimental comparison with a standard BGO suppresser is shown. We also discuss the possible improvements to the current PSA approach that could be obtained if the HPGe could be highly segmented on the outer contact.
Date: April 15, 1998
Creator: Schmid, G. J.; Beckedahl, D.; Blair, J. J. & Kammeraad, J. E.
Object Type: Article
System: The UNT Digital Library
Investigations of plutonium immobilization into the vitreous compositions (open access)

Investigations of plutonium immobilization into the vitreous compositions

Development and characterizations of phosphate and borosilicate glasses for vitrifying high level waste (HLW) solutions in Russia has been extensive. The technical data generated were for low concentrations (less than 0.05% Pu) of plutonium. Limited studies have been performed with plutonium concentrations one to two orders of magnitude larger. The results of these studies are being used to plan and implement an expanded experimental program to establish the limitations and characteristics of plutonium in similar glass compositions.
Date: April 15, 1998
Creator: Matyunin, Y.I.,
Object Type: Article
System: The UNT Digital Library
NWIS casting measurements taken during demonstrations to Russian visitors (open access)

NWIS casting measurements taken during demonstrations to Russian visitors

This report describes a set of NWIS measurements made during demonstrations to Russian visitors on August 28, 1997. These measurements will be given to the Russian visitors from Arzamus-16 as part of their NWIS training (part of a DOE laboratory-to-laboratory exchange program). These measurements are made on standard highly enriched Uranium annular castings (as used for storage). Associated NWIS calibration runs were made in air (no casting, just the NWIS Californium source and detectors).
Date: April 15, 1998
Creator: Mullens, J. A.; Valentine, T. E. & Mihalczo, J. T.
Object Type: Report
System: The UNT Digital Library
Final Technical Report: Ocean CO{sub 2} Measurements for the WOCE Hydrographic Survey in the Pacific Ocean, 1992-1995 Field Years: Shore Based Analysis of Dissolved Inorganic Carbon January 1, 1993-April 15, 1998 (open access)

Final Technical Report: Ocean CO{sub 2} Measurements for the WOCE Hydrographic Survey in the Pacific Ocean, 1992-1995 Field Years: Shore Based Analysis of Dissolved Inorganic Carbon January 1, 1993-April 15, 1998

Participation in the hydrographic survey of the world ocean circulation experiment (WOCE) began in December 1990 with a two year grant from DOE for shore related analyses of inorganic carbon in sea water. These analyses were intended to assure that the measurements carried out under difficult laboratory conditions on board ships were consistent with measurements made under more carefully controlled shore laboratory conditions.
Date: April 15, 1998
Creator: Keeling, Charles D.
Object Type: Report
System: The UNT Digital Library
Investigation of syngas interactions in alcohol synthesis catalyst (open access)

Investigation of syngas interactions in alcohol synthesis catalyst

The primary objectives of the project are to (a) synthesize, by controlled sequential and co-impregnation techniques, three distinct composition metal clusters (consisting of Cu-Co-Cr and Cu-Fe-Zn): rich in copper (Methanol selective), rich in ferromagnetic metal (Co or Fe-Hydrocarbon selective) and intermediate range (mixed alcohol catalysts); (b) investigate the changes in the magnetic character of the systems due to interaction with CO, through Zero-field Nuclear Magnetic Resonance (ZFNMR) study of cobalt and Magnetic character (saturation magnetization and coercive field) analysis of the composite catalyst of Vibrating Sample Magnetometry (VSM); (c) examine the changes in syngas adsorption character of the catalyst as the composition changes, by FTIR Spectroscopic analysis of CO stretching frequencies; (d) determine the nature and size of these intermetallic clusters by Scanning Electron Microscopy (SEM); and (e) perform catalytic runs on selected samples and analyze the correlations between the physical and chemical characteristics. The catalysts chosen have a greater promise for industrial application than the Rh and Mo based catalysts. Several groups preparing catalysts by synthetic routes have reported divergent results for activity and selectivity. Generally the research has followed an empirical path and less effort is devoted to analyze the mechanisms and the scientific basis. The primary intent …
Date: April 15, 1998
Creator: Akundi, M. A.
Object Type: Report
System: The UNT Digital Library
Improved oil recovery in fluvial dominated deltaic reservoirs of Kansas -- Near-term. Quarterly report, January 1--March 31, 1998 (open access)

Improved oil recovery in fluvial dominated deltaic reservoirs of Kansas -- Near-term. Quarterly report, January 1--March 31, 1998

The objective of this project is to address waterflood problems of the type found in Morrow sandstone reservoirs in southwestern Kansas and in Cherokee Group reservoirs in southeastern Kansas. Two demonstration sites operated by different independent oil operators are involved in this project. The Stewart Field is located in Finney County, Kansas and is operated by PetroSantander, Inc. The Nelson Lease is located in Allen County, Kansas, in the N.E. Savonburg Field and is operated by James E. Russell Petroleum, Inc. General topics to be addressed are (1) reservoir management and performance evaluation, (2) waterflood optimization, and (3) the demonstration of recovery processes involving off-the-shelf technologies which can be used to enhance waterflood recovery, increase reserves, and reduce the abandonment rate of these reservoir types. Progress is described for the Stewart field on the following tasks: design/construct waterflood plant; design/construct injection system; design/construct battery consolidation and gathering system; waterflood operations and reservoir management; and technology transfer. Progress for the Savonburg Field includes: water plant development; profile modification treatments; pattern changes and wellbore cleanup; reservoir development (polymer flooding); field operations; and technology transfer.
Date: April 15, 1998
Creator: Green, D.W.; Willhite, G.P.; Walton, A.; McCune, D.; Reynolds, R.; Michnick, M. et al.
Object Type: Report
System: The UNT Digital Library
Fly ash-enhanced aluminum composites for automotive parts. [Reports for October to December, 1997, and January to March, 1998] (open access)

Fly ash-enhanced aluminum composites for automotive parts. [Reports for October to December, 1997, and January to March, 1998]

The objectives of this report are to produce and evaluate the use of aluminum ''ashalloys''--metal matrix composites that incorporate coal fly ash--in the commercial manufacture of cast automotive parts. Some highlights of this report are: Results of the team coordination meeting in October included--(1) Determination of casting techniques from the candidates of squeeze, high pressure, low pressure, sand casting, and gravity pour; (2) Selection of the low stress/high stress automotive parts from the candidates of brake rotors, intake manifolds, and engine mounts; (3) Integration of the tasks essential for evaluating the fly ash characteristics and appropriate percentages of cenospheres or precipitator in the parts. Fly ash from two plants of Wisconsin Electric Power Company (WEPCo) was dispatched to the laboratories of JTM and UW-M for screening, characterization, and beneficiation. The fly ash was classified into different size fractions and is being analyzed for chemical composition and microstructure. Currently, fly ash beneficiation is removing the carbon, magnetic fractions, and sulfur. After classification and screening, JTM will deliver the processed fly ash to UW-M. Foundries are providing UW-M with information on the specific alloys needed for parts. Thompson Aluminum sent the base alloy 356 to UW-M where, in turn, small size ingots …
Date: April 15, 1998
Creator: Golden, Dean & Rohatgi, Pradeep
Object Type: Report
System: The UNT Digital Library
In-Situ Tritium Beta Detector (open access)

In-Situ Tritium Beta Detector

The objectives of this three-phase project were to design, develop, and demonstrate a monitoring system capable of detecting and quantifying tritium in situ in ground and surface waters, and in water from effluent lines prior to discharge into public waterways. The tritium detection system design is based on measurement of the low energy beta radiation from the radioactive decay of tritium using a special form of scintillating optical fiber directly in contact with the water to be measured. The system consists of the immersible sensor module containing the optical fiber, and an electronics package, connected by an umbilical cable. The system can be permanently installed for routine water monitoring in wells or process or effluent lines, or can be moved from one location to another for survey use. The electronics will read out tritium activity directly in units of pico Curies per liter, with straightforward calibration. In Phase 1 of the project, we characterized the sensitivity of fluor-doped plastic optical fiber to tritium beta radiation. In addition, we characterized the performance of photomultiplier tubes needed for the system. In parallel with this work, we defined the functional requirements, target specifications, and system configuration for an in situ tritium beta detector …
Date: April 15, 1998
Creator: Berthold, J. W. & Jeffers, L. A.
Object Type: Report
System: The UNT Digital Library
Numerical experiments on the probability of seepage intounderground openings in heterogeneous fractured rock (open access)

Numerical experiments on the probability of seepage intounderground openings in heterogeneous fractured rock

An important issue for the performance of underground nuclear waste repositories is the rate of seepage into the waste emplacement drifts. A prediction of this rate is particularly complicated for the potential repository site at Yucca Mountain, Nevada, because it is located in thick, unsaturated, fractured tuff formations. Underground opening in unsaturated media might act as capillary barriers, diverting water around them. In the present work, they study the potential rate of seepage into drifts as a function of the percolation flux at Yucca Mountain, based on a stochastic model of the fractured rock mass in the drift vicinity. A variety of flow scenarios are considered, assuming present-day and possible future climate conditions. They show that the heterogeneity in the flow domain is a key factor controlling seepage rates, since it causes channelized flow and local ponding in the unsaturated flow field.
Date: April 15, 1998
Creator: Birkholzer, J.; Li, G.; Tsang, C. F. & Tsang, Y.
Object Type: Report
System: The UNT Digital Library