Wide area continuous offender monitoring (open access)

Wide area continuous offender monitoring

The corrections system in the U.S. is supervising over five million offenders. This number is rising fast and so are the direct and indirect costs to society. To improve supervision and reduce the cost of parole and probation, first generation home arrest systems were introduced in 1987. While these systems proved to be helpful to the corrections system, their scope is rather limited because they only cover an offender at a single location and provide only a partial time coverage. To correct the limitations of first-generation systems, second-generation wide area continuous electronic offender monitoring systems, designed to monitor the offender at all times and locations, are now on the drawing board. These systems use radio frequency location technology to track the position of offenders. The challenge for this technology is the development of reliable personal locator devices that are small, lightweight, with long operational battery life, and indoors/outdoors accuracy of 100 meters or less. At the center of a second-generation system is a database that specifies the offender`s home, workplace, commute, and time the offender should be found in each. The database could also define areas from which the offender is excluded. To test compliance, the system would compare the …
Date: November 1, 1996
Creator: Hoshen, J.; Drake, G. & Spencer, D.
Object Type: Article
System: The UNT Digital Library
Title list of documents made publicly available: September 1--30, 1996. Volume 18, Number 9 (open access)

Title list of documents made publicly available: September 1--30, 1996. Volume 18, Number 9

The report describes the information received and published by the US Nuclear Regulatory Commission (NRC). This information includes (1) docketed material associated with civilian nuclear power plants and other uses of radioactive materials and (2) non-docketed material received and published by NRC pertinent to its role as a regulatory agency. As used here, docketed does not refer to Court dockets; it refers to the system by which NRC maintains its regulatory records. This series of documents is indexed by a Personal Author Index, a Corporate Source Index, and a Report Number Index.
Date: November 1, 1996
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Physics Division annual report, April 1, 1995--March 31, 1996 (open access)

Physics Division annual report, April 1, 1995--March 31, 1996

The past year has seen several major advances in the Division`s research programs. In heavy-ion physics these include experiments with radioactive beams of interest to nuclear astrophysics, a first exploration of the structure of nuclei situated beyond the proton drip line, the discovery of new proton emitters--the heaviest known, the first unambiguous detection of discrete linking transitions between superdeformed and normal deformed states, and the impact of the APEX results which were the first to report, conclusively, no sign of the previously reported sharp electron positron sum lines. The medium energy nuclear physics program of the Division has led the first round of experiments at the CEBAF accelerator at the Thomas Jefferson National Accelerator Facility and the study of color transparency in rho meson propagation at the HERMES experiment at DESY, and it has established nuclear polarization in a laser driven polarized hydrogen target. In atomic physics, the non-dipolar contribution to photoionization has been quantitatively established for the first time, the atomic physics beamline at the Argonne 7 GeV Advanced Photon Source was constructed and, by now, first experiments have been successfully performed. The theory program has pushed exact many-body calculations with fully realistic interactions (the Argonne v{sub 18} potential) …
Date: November 1, 1996
Creator: Thayer, K. J.
Object Type: Report
System: The UNT Digital Library
Demonstration of oxygen-enriched air staging at Owens-Brockway Glass Containers. Technical progress report, August 1, 1995--July 31, 1996 (open access)

Demonstration of oxygen-enriched air staging at Owens-Brockway Glass Containers. Technical progress report, August 1, 1995--July 31, 1996

The objective of the program is to demonstrate the use of a previously developed combustion modification technology to reduce NO, emissions from sideport regenerative container glass melters. This technology, known as oxygen-enriched air staging (OEAS), has been demonstrated, and is now being commercialized, for endport container glass furnaces. A 17-month development program has been established with specific objectives to: (1) acquire baseline operating data on the host sideport furnace in Vernon, California, (2) evaluate secondary oxidant injection strategies based on earlier endport furnace results and through modeling of a single port pair, (3) retrofit and test one port pair (the test furnace has six port pairs) with a flexible OEAS system, and select the optimal system configuration, (4) use the results from tests with one port pair to design, retrofit, and test OEAS on the entire furnace (six port pairs), and (5) analyze test results, prepare report, and finalize the business plan to commercialize OEAS for sideport furnaces. The host furnace for testing in this program is an Owens-Brockway 6-port pair sideport furnace in Vernon, California producing 325-ton/d of amber container glass. The baseline NO{sub x} level of this optimized furnace is about 4.0 lb/ton of glass. An anticipated NO{sub …
Date: November 1, 1996
Creator: Rue, D. & Abbasi, H.
Object Type: Report
System: The UNT Digital Library
Top mass measurements at CDF (open access)

Top mass measurements at CDF

We report on measurements of the top quark mass by the CDF experiment at the FermiLab Tevatron collider. The top quark is produced in {ital p{anti p}} collisions at {radical}{ital s} = 1.8 TeV. The analyses use an integrated luminosity of 110 pb{sup -1}. Results are presented from three decay channels, (i) one lepton plus jets, (ii) dilepton, (iii) all hadronic. The smallest error on the mass comes from (i), with a preliminary top mass value of 175.6 {+-}4.4 (stat.) {+-} 4.8 (syst.) GeV. Results from the other channels are consistent with this value.
Date: November 1, 1996
Creator: Lys, J.
Object Type: Article
System: The UNT Digital Library
A pure permanent magnet-two plane focusing-tapered wiggler for a high average power FEL (open access)

A pure permanent magnet-two plane focusing-tapered wiggler for a high average power FEL

A high-average power FEL is under construction at Los Alamos. The FEL will have aspects of both an oscillator and a SASE (self-amplified spontaneous emission) device. That is, a high-gain and high- extraction efficiency wiggler will be used with a very low-Q optical resonator. FEL simulations reveal that a tapered wiggler with two- plane focusing is required to obtain desired performance. The wiggler is comprised of a I meter long untapered section followed by a 1 meter tapered section. The taper is achieved with the magnetic gap and not the wiggler period which is constant at 2 cm. The gap is tapered from 5.9 mm to 8.8 mm. The, gap, rather than the period, is tapered to avoid vignetting of the 16 {mu}m optical beam. Two-plane focusing is necessary to maintain high current density and thus high gain through out the 2 meter long wiggler. Several magnetic designs have been considered for the wiggler. The leading candidate approach is a pure permanent wiggler with pole faces that are cut to roughly approximate the classical parabolic pole face design. Focusing is provided by the sextupole component of the wiggler magnetic field and is often called ``natural`` or ``betatron`` focusing. Details of …
Date: November 1, 1996
Creator: Fortgang, C.M.
Object Type: Article
System: The UNT Digital Library
Determination of plutonium in urine: evaluation of electrothermal vaporization inductively coupled plasma mass spectroscopy (open access)

Determination of plutonium in urine: evaluation of electrothermal vaporization inductively coupled plasma mass spectroscopy

Mass spectroscopy has the distinct advantage of detecting atoms rather than radioactive decay products for nuclides of low specific activity. Electrothermal vaporization (ETV) is an efficient means of introducing small volumes of prepared samples into an inductively coupled mass spectrometer to achieve the lowest absolute detection limits. The operational characteristics and capabilities of electrothermal vaporization inductively coupled mass spectrometer mass spectroscopy were evaluated. We describe its application as a detection method for determining Pu in urine, in conjunction with a preliminary separation technique to avoid matrix suppression of the signal.
Date: November 1, 1996
Creator: Pietrzak, R. & Kaplan, E.
Object Type: Article
System: The UNT Digital Library
Plutonium Focus Area research and development plan. Revision 1 (open access)

Plutonium Focus Area research and development plan. Revision 1

The Department of Energy (DOE) committed to a research and development program to support the technology needs for converting and stabilizing its nuclear materials for safe storage. The R and D Plan addresses five of the six material categories from the 94-1 Implementation Plan: plutonium (Pu) solutions, plutonium metals and oxides, plutonium residues, highly enriched uranium, and special isotopes. R and D efforts related to spent nuclear fuel (SNF) stabilization were specifically excluded from this plan. This updated plan has narrowed the focus to more effectively target specific problem areas by incorporating results form trade studies. Specifically, the trade studies involved salt; ash; sand, slag, and crucible (SS and C); combustibles; and scrub alloy. The plan anticipates possible disposition paths for nuclear materials and identifies resulting research requirements. These requirements may change as disposition paths become more certain. Thus, this plan represents a snapshot of the current progress and will continue to be updated on a regular basis. The paper discusses progress in safeguards and security, plutonium stabilization, special isotopes stabilization, highly-enriched uranium stabilization--MSRE remediation project, storage technologies, engineered systems, core technology, and proposed DOE/Russian technology exchange projects.
Date: November 1, 1996
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Summary of proposed approach for deriving cleanup guidelines for radionuclides in soil at Brookhaven National Laboratory (open access)

Summary of proposed approach for deriving cleanup guidelines for radionuclides in soil at Brookhaven National Laboratory

Past activities at Brookhaven National Laboratory (BNL) resulted in soil and groundwater contamination. As a result, BNL was designated a Superfund site under the Comprehensive Environmental Response Compensation and Liability Act (CERCLA). BNL`s Office of Environmental Restoration (OER) is overseeing environmental restoration activities at the Laboratory, carried out under an Interagency Agreement (IAG) with the United States Department of Energy (DOE), the United States Environmental Protection Agency (EPA) and the New York State Department of Environmental Conservation (NYSDEC). The objective of this paper is to propose a standard approach to deriving risk-based cleanup guidelines for radionuclides in soil at BNL.
Date: November 1, 1996
Creator: Meinhold, A.F.; Morris, S.C.; Dionne, B. & Moskowitz, P.D.
Object Type: Report
System: The UNT Digital Library
Benchmarking WASP5 with data from the 1991 K-Reactor tritiated aqueous release incident (open access)

Benchmarking WASP5 with data from the 1991 K-Reactor tritiated aqueous release incident

The Savannah River Site (SRS) has upgraded its aqueous emergency response capability to model the transport of pollutants released from SRS facilities during normal operation or accidents through onsite streams to the Savannah River. The transport and dispersion modules from the US Environmental Protection Agency (EPA) WASP5 model were incorporated into the SRS emergency response system, called the Weather Information and Display (WIND) System. WASP5 is a water quality analysis program that simulates surface water pollutant transport, using a finite difference method to solve the advective transport equation. Observed tritium concentrations in the SRS streams and the Savannah River from an accidental release from K-Reactor, one of the SRS nuclear material production reactors, were used to benchmark the new model. Although all SRS reactors have since been deactivated, this release of tritiated water occurred between December 22 and 25, 1991, through the K-Reactor secondary cooling water discharge. Analyses of reactor discharge water suggested the leak began sometime during December 22. The leak was positively identified and isolated on December 25. Following the release, tritium concentrations were tracked and measured as the tritiated water flowed from the K-Area outfall into Indian Grave Branch and pen Branch, through the Savannah River swamp, …
Date: November 7, 1996
Creator: Chen, K.F.
Object Type: Article
System: The UNT Digital Library
A design study for the isolation of the 281-3H retention basin at the Savannah River Site using the viscous liquid barrier technology (open access)

A design study for the isolation of the 281-3H retention basin at the Savannah River Site using the viscous liquid barrier technology

This report is a description of the design study for a pilot-scale field demonstration of the Viscous Liquid Barrier (VLB) technology, a new subsurface containment technology for waste isolation using a new generation of barrier liquids. The demonstration site was Retention Basin 281-3H, a shallow catchment basin at the Savannah River Site, which is contaminated mainly by radionuclides ({sup 137}Cs, {sup 90}Sr, and {sup 238}Pu). The goals of the field demonstration were (a) to demonstrate the ability to create a continuous subsurface barrier in order to isolate the contaminants, and (b) to demonstrate the continuity, performance, and integrity of the barrier. The site was characterized, and preliminary hydraulic conductivity data were obtained from core samples. Based on the site characteristics and the functional requirements, a conceptual model was developed, the barrier specifications were defined, and lance injection was selected as the emplacement method. The injection strategy for the subsurface conditions at the site was determined using numerical simulations. An appropriate variant of Colloidal Silica (CS) was selected as the barrier liquid based on its relative insensitivity to interactions with the site soils, and the formulation for optimum site performance was determined. A barrier verification strategy, including hydraulic, pneumatic, tracer, and …
Date: November 1, 1996
Creator: Moridis, G.J.; Persoff, P.; Apps, J.; James, A.; Oldenburg, C.; McGrath, A. et al.
Object Type: Report
System: The UNT Digital Library
Fundamental studies of matrix-assisted laser desorption/ionization, using time-of-flight mass spectrometry to identify biological molecules (open access)

Fundamental studies of matrix-assisted laser desorption/ionization, using time-of-flight mass spectrometry to identify biological molecules

MALDI MS was developed as a way of getting molecular weight information on small quantities (picomole to femtomole levels) of high-mass, thermally labile macromolecules. While most other analytical MS ionization techniques cause fragmentation, decomposition, or multiple charging, MALDI efficiently places intact macromolecules into the gas phase with little fragmentation or rearrangement. This project had 3 objectives: establish the MALDI capability at LLNL, perform fundamental studies of analyte-matrix interactions, and apply the technique for biochemical research. A retired time-of-flight instrument was adapted for MALDI analyses, relevant parameters influencing the MALDI process were identified for further study (matrix molar absorptivity, sample crystal preparation), and collaborations were established with research groups in the Biology and Biotechnology Research Program at LLNL. In MALDI, the macromolecule of interest is mixed with a high-molar excess (1:100 to 1:10,000) of an organic matrix which readily absorbs energy at the wavelength corresponding to a UV laser. Upon laser irradiation, the matrix absorbs the majority of the energy, causing it to desorb from the surface and gently release the macromolecule into the gas phase with little or no fragmentation. Once in the gas phase, ion-molecule reactions between excited matrix and neutral macromolecules generated ionized analyte species which then can …
Date: November 11, 1996
Creator: Eades, D.; Wruck, D. & Gregg, H.
Object Type: Report
System: The UNT Digital Library
U.S. Environmental Protection Agency Clear Air Act notice of construction for the spent nuclear fuel project - Cold Vaccum Drying Facility, project W-441 (open access)

U.S. Environmental Protection Agency Clear Air Act notice of construction for the spent nuclear fuel project - Cold Vaccum Drying Facility, project W-441

This document provides information regarding the source and the estimated quantity of potential airborne radionuclide emissions resulting from the operation of the Cold Vacuum Drying (CVD) Facility. The construction of the CVD Facility is scheduled to commence on or about December 1996, and will be completed when the process begins operation. This document serves as a Notice of Construction (NOC) pursuant to the requirements of 40 Code of Federal Regulations (CFR) 61 for the CVD Facility. About 80 percent of the U.S. Department of Energy`s spent nuclear fuel (SNF) inventory is stored under water in the Hanford Site K Basins. Spent nuclear fuel in the K West Basin is contained in closed canisters, while the SNF in the K East Basin is in open canisters, which allow release of corrosion products to the K East Basin water. Storage of the current inventory in the K Basins was originally intended to be on an as-needed basis to sustain operation of the N Reactor while the Plutonium-Uranium Extraction (PUREX) Plant was refurbished and restarted. The decision in December 1992 to deactivate the PURF-X Plant left approximately 2,100 MT (2,300 tons) of uranium as part of the N Reactor SNF in the K …
Date: November 25, 1996
Creator: Turnbaugh, J.E.
Object Type: Report
System: The UNT Digital Library
Core V{sub {phi}} and T{sub i} profiles and transport in TFTR DD and DT plasmas with lithium conditioning (open access)

Core V{sub {phi}} and T{sub i} profiles and transport in TFTR DD and DT plasmas with lithium conditioning

High performance DT plasmas have been obtained using neutral beam heating with lithium (Li) conditioned graphite walls in TFTR. Values of {tau}{sub E} > 300 ms have been obtained with neutron source rates of >10{sup 18} n/s and n{tau}T {approx} 10{sup 21}. Also, ion temperature (T{sub i}) > 40 keV and toroidal velocity (V{sub {phi}}) > 800 km/s have been obtained. The T{sub i}(R,t) and V{sub {phi}}(R,t) profiles show strong gradients near the plasma core with{gradient}V{sub {phi}} > 3.5 {times} 10{sup 6}/s and E{times}B shearing rate >2 {times} 10{sup 5}/s realized. This strong ExB flow shear is consistent with formation of a transport barrier in the plasma core. Measured V{sub {phi}}, T{sub i}, and carbon density, n{sub c}, profiles from charge-exchange recombination spectroscopy (CHERS) and neoclassical calculations of poloidal velocity, V{sub {theta}}, are used to assess the roles of the pressure and velocity contributions to E{sub r} (or ExB) with varying Li conditioning. The profiles and gradients and resulting confinement and transport are found to vary with the amount of Li applied and the Li deposition technique. Correlations between the V{sub {phi}} and T{sub i} profiles and recycling and impurity behavior as implied from edge carbon and D{sub {alpha}} light …
Date: November 1, 1996
Creator: Bush, C.E.; Bell, R.E. & LeBlanc, B.
Object Type: Report
System: The UNT Digital Library
Experimental and theoretical investigations of shock-induced flow of reactive porous media (open access)

Experimental and theoretical investigations of shock-induced flow of reactive porous media

In this work, the microscale processes of consolidation, deformation and reaction features of shocked porous materials are studied. Time- resolve particle velocities and stress fields associated with dispersive compaction waves are measured in gas-gun experiments. In these tests, a thin porous layer of HMX is shock-loaded at varied levels. At high impact, significant reaction is triggered by the rapid material distortion during compaction. In parallel modeling studies, continuum mixture theory is applied to describe the behavior of averaged wave-fields in heterogeneous media. One-dimensional simulations of gas-gun experiments demonstrate that the wave features and interactions with viscoelastic materials in the gauge package are well described by mixture theory, including reflected wave behavior and conditions where significant reaction is initiated. Numerical simulations of impact on a collection of discrete HMX `crystals` are also presented using shock physics analysis. Three-dimensional simulations indicate that rapid distortion occurs at material contact points; the nature of the dispersive fields includes large amplitude fluctuations of stress with wavelengths of several particle diameters. Localization of energy causes `hot-spots` due to shock focusing and plastic work as material flows into interstitial regions. These numerical experiments demonstrate that `hot-spots` are strongly influenced by multiple crystal interactions. This mesoscale study provides …
Date: November 1, 1996
Creator: Baer, M. R.; Graham, R. A.; Anderson, M. U.; Sheffield, S. A. & Gustavsen, R. L.
Object Type: Article
System: The UNT Digital Library
Career toolbox - the decision paper: A tool to facilitate decision-making (open access)

Career toolbox - the decision paper: A tool to facilitate decision-making

Guidelines for writing a decision paper are presented. The purpose of the decision paper is to present complex issues in an organized format; it is especially helpful when timeliness is important. The writing style and format of the decision paper are described. The format for a decision paper includes the issue or problem statement, relevant background material, options or alternatives, discussion, recommendation, coordination/endorsement, and record of decision.
Date: November 12, 1996
Creator: Williams, J.L. & Petersen, T.P.
Object Type: Article
System: The UNT Digital Library
Neoclassical transport in enhanced confinement toroidal plasmas (open access)

Neoclassical transport in enhanced confinement toroidal plasmas

It has recently been reported that ion thermal transport levels in enhanced confinement tokamak plasmas have been observed to fall below the irreducible minimum level predicted by standard neoclassical theory. This apparent contradiction is resolved in the present analysis by relaxing the basic neoclassical assumption that the ions orbital excursions are much smaller than the local toroidal minor radius and the equilibrium scale lengths of the system.
Date: November 1, 1996
Creator: Lin, Z.; Tang, W. M. & Lee, W. W.
Object Type: Report
System: The UNT Digital Library
Large-eddy simulation in complex domains using the finite element method (open access)

Large-eddy simulation in complex domains using the finite element method

Finite element methods (FEM) are demonstrated in combination with large-eddy simulations (LES) as a valuable tool for the study of turbulent, separating channel flows, specifically the flow over a backward facing step.
Date: November 12, 1996
Creator: McCallen, R.C.; Kornblum, B.T. & Kollman, W.
Object Type: Article
System: The UNT Digital Library
Joining of silicon carbide using interlayer with matching coefficient of thermal expansion (open access)

Joining of silicon carbide using interlayer with matching coefficient of thermal expansion

The primary objective of this study is to develop a technique for joining a commercially available Silicon Carbide that gives good room temperature strength and the potential for good high temperature strength. One secondary objective is that the joining technique be adaptable to SiC{sub f}/SiC composites and/or Nickel based superalloys, and another secondary objective is that the materials provide good neutron irradiation resistance and low activation for potential application inside nuclear fusion reactors. The joining techniques studied here are: (1) reaction bonding with Al-Si/Si/SiC/C; (2) reaction/infiltration with calcium aluminum silicate; (3) ion exchange mechanism to form calcium hexaluminate (a refractory cement); and (4) oxide frit brazing with cordierite.
Date: November 1, 1996
Creator: Perham, T.
Object Type: Report
System: The UNT Digital Library
Few-valence-particle excitations around doubly magic {sup 132}Sn (open access)

Few-valence-particle excitations around doubly magic {sup 132}Sn

Prompt {gamma}-ray cascades in neutron-rich nuclei around doubly-magic {sup 132}Sn have been studied using a {sup 248}Cm fission source. Yrast states located in the N = 82 isotones {sup 134}Te and {sup 135}I are interpreted as valence proton and neutron particle-hole core excitations with the help of shell model calculations employing empirical nucleon-nucleon interactions from both {sup 132}Sn and {sup 208}Pb regions.
Date: November 1, 1996
Creator: Daly, P. J.; Zhang, C. T. & Bhattacharyya, P.
Object Type: Article
System: The UNT Digital Library
Multidimensional reactor kinetics modeling (open access)

Multidimensional reactor kinetics modeling

There is general agreement that for many light water reactor transient calculations, it is-necessary to use a multidimensional neutron kinetics model coupled to a thermal-hydraulics model for satisfactory results. These calculations are needed for a variety of applications for licensing safety analysis, probabilistic risk assessment (PRA), operational support, and training. The latter three applications have always required best-estimate models, but in the past applications for licensing could be satisfied with relatively simple models. By using more sophisticated best-estimate models, the consequences of these calculations are better understood, and the potential for gaining relief from restrictive operating limits increases. Hence, for all of the aforementioned applications, it is important to have the ability to do best-estimate calculations with multidimensional neutron kinetics models. coupled to sophisticated thermal-hydraulic models. Specifically, this paper reviews the status of multidimensional neutron kinetics modeling which would be used in conjunction with thermal-hydraulic models to do core dynamics calculations, either coupled to a complete NSSS representation or in isolation. In addition, the paper makes recommendations as to what should be the state-of-the-art for the next ten years. The review is an update to a previous review of the status as of ten years ago. The general requirements for …
Date: November 1, 1996
Creator: Diamond, D. J.
Object Type: Article
System: The UNT Digital Library
Nuclear fuels technologies Fiscal Year 1996 research and development test results (open access)

Nuclear fuels technologies Fiscal Year 1996 research and development test results

During fiscal year 1996, the Department of Energy`s Office of Fissile Materials Disposition (OFMD) funded Los Alamos National Laboratory (LANL) to investigate issues associated with the fabrication of plutonium from dismantled weapons into mixed-oxide (MOX) nuclear fuel for disposition in nuclear power reactors. These issues can be divided into two main categories: issues associated with the fact that the plutonium from dismantled weapons contains gallium, and issues associated with the unique characteristics of the PuO[sub 2] produced by the dry conversion process that OFMD is proposing to convert the weapons material. Initial descriptions of the experimental work performed in fiscal year 1996 to address these issues can be found in Nuclear Fuels Technologies Fiscal Year 1996 Research and Development Test Matrices. However, in some instances the change in programmatic emphasis towards the Parallex program either altered the manner in which some of these experiments were performed (i.e., the work was done as part of the Parallex fabrication development and not as individual separate-effects tests as originally envisioned) or delayed the experiments into Fiscal Year 1997. This report reviews the experiments that were conducted and presents the results.
Date: November 1, 1996
Creator: Beard, C. A.; Blair, H. T.; Buksa, J. J.; Butt, D. P.; Chidester, K.; Eaton, S. L. et al.
Object Type: Report
System: The UNT Digital Library
General-purpose heat source: Research and development program, radioisotope thermoelectric generator/thin fragment impact test (open access)

General-purpose heat source: Research and development program, radioisotope thermoelectric generator/thin fragment impact test

The general-purpose heat source provides power for space missions by transmitting the heat of {sup 238}Pu decay to an array of thermoelectric elements in a radioisotope thermoelectric generator (RTG). Because the potential for a launch abort or return from orbit exists for any space mission, the heat source response to credible accident scenarios is being evaluated. This test was designed to provide information on the response of a loaded RTG to impact by a fragment similar to the type of fragment produced by breakup of the spacecraft propulsion module system. The results of this test indicated that impact by a thin aluminum fragment traveling at 306 m/s may result in significant damage to the converter housing, failure of one fueled clad, and release of a small quantity of fuel.
Date: November 1, 1996
Creator: Reimus, M.A.H. & Hinckley, J.E.
Object Type: Report
System: The UNT Digital Library
Phase coexistence in proton glass (open access)

Phase coexistence in proton glass

Proton glasses are crystals of composition M{sub 1{minus}x}(NW{sub 4}){sub x}W{sub 2}AO{sub 4}, where M = K,Rb, W = H,D, A = P,As. For x = 0 there is a ferroelectric (FE) transition, while for x = 1 there is an antiferroelectric (AFE) transition. In both cases, the transition is from a paraelectric (PE) state of tetragonal structure with dynamically disordered hydrogen bonds to an ordered state of orthorhombic structure. For an intermediate x range there is no transition, but the hydrogen rearrangements slow down, and eventually display nonergodic behavior characteristic of glasses. The authors and other have shown from spontaneous polarization, dielectric permittivity, nuclear magnetic resonance, and neutron diffraction experiments that for smaller x there is coexistence of ferroelectric and paraelectric phases, and for larger x there is coexistence of antiferroelectric and paraelectric phases. The authors present a method for analytically describing this coexistence, and the degree to which this coexistence is spatial or temporal.
Date: November 1, 1996
Creator: Schmidt, V. H.; Trybula, Z.; Pinto, N. J. & Shapiro, S. M.
Object Type: Article
System: The UNT Digital Library