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Anchor Toolkit - a secure mobile agent system (open access)

Anchor Toolkit - a secure mobile agent system

Mobile agent technology facilitates intelligent operation insoftware systems with less human interaction. Major challenge todeployment of mobile agents include secure transmission of agents andpreventing unauthorized access to resources between interacting systems,as either hosts, or agents, or both can act maliciously. The Anchortoolkit, designed by LBNL, handles the transmission and secure managementof mobile agents in a heterogeneous distributed computing environment. Itprovides users with the option of incorporating their security managers.This paper concentrates on the architecture, features, access control anddeployment of Anchor toolkit. Application of this toolkit in a securedistributed CVS environment is discussed as a case study.
Date: May 19, 1999
Creator: Mudumbai, Srilekha S.; Johnston, William & Essiari, Abdelilah
System: The UNT Digital Library
ARAC Modeling of the Algeciras, Spain Steel Mill CS-137 Release (open access)

ARAC Modeling of the Algeciras, Spain Steel Mill CS-137 Release

On 12 June 1998, the Atmospheric Release Advisory Capability (ARAC) learned from news reports about the accidental release of cesium-137 from a steel mill near Algeciras, Spain. We used the U.S. Navy Operational Global Atmospheric Prediction System (NOGAPS) gridded data for meteorological input into our diagnostic models. To better resolve near-release location and coastal meteorological conditions, we blended four days of WMO surface and upper air observations with the gridded data. Our calculations showed the plume initially traveled eastward over the Mediterranean Sea, turned northward into central Europe, and was split by the Alps. We determined the timing and amount of cesium released by fitting our modeled air concentrations to the available set of measurements. Accuracy statistics from a small set of ratios of measured to computed air concentrations paired in space and time were similar to those achieved from larger data sets in previous ARAC model evaluation studies on the continental scale.
Date: May 1, 1999
Creator: Vogt, P J; Pobanz, B M; Aluzzi, F J; Baskett, R L & Sullivan, T J
System: The UNT Digital Library
Dynamic Holographic Lock-In Imaging of Ultrasonic Waves (open access)

Dynamic Holographic Lock-In Imaging of Ultrasonic Waves

A laser imaging approach is presented that utilizes the adaptive property of photorefractive materials to produce a real-time measurement of ultrasonic traveling wave surface displacement and phase in all planar directions simultaneously without scanning. The imaging method performs optical lock-in operation. A single antisymmetric Lamb wave mode image produces direct quantitative determination of the phase velocity in all planar directions showing plate stiffness anisotropy. Excellent agreement was obtained with modeling calculations of the phase velocity in all planar directions for an anisotropic sheet material. The approach functions with diffusely scattering surfaces, subnanometer motions and at frequencies from Hz to GHz.
Date: May 1, 1999
Creator: Telschow, Kenneth Louis; Deason, Vance Albert & Datta, S.K.
System: The UNT Digital Library
Completion of the INEEL's WERF Incinerator Trial Burn (open access)

Completion of the INEEL's WERF Incinerator Trial Burn

This paper describes the successes and challenges associated with Resource Conservation and Recovery Act (RCRA) permitting of the Idaho National Engineering and Environmental Laboratory's (INEEL) Waste Experimental Reduction Facility (WERF) hazardous and mixed waste incinerator. Topics to be discussed include facility modifications and problems, trial burn results and lessons learned in each of these areas. In addition, a number of challenges remain including completion and final issue of RCRA Permit and implementation of all the permit requirements. Results from the trial burn demonstrated that the operating conditions and procedures will result in emissions that are satisfactorily protective of human health, the environment, and are in compliance with Federal and State regulations.
Date: May 1, 1999
Creator: Branter, Curtis Keith; Conley, Dennis Allen; Corrigan, Shannon James & Moser, David Roy
System: The UNT Digital Library
INEEL Worker Involvement as a Means of Controlling Their Own Safety (open access)

INEEL Worker Involvement as a Means of Controlling Their Own Safety

Using the eight guiding principles of Integrated Safety Management (ISM) - Worker Involvement - will move the work force on a forward path from just doing work to doing work safely. This path can be achieved by changing the safety culture in the work place. The work force is more likely to accept a process that will allow them to be accountable for their own safety if they feel ownership through Worker Involvement. The marrying of the Voluntary Protection Program (VPP) and ISM will give workers this ownership. One of the concerns in implementing ISM is that, unless you keep it simple by applying the five core functions and eight guiding principles, you may over load the work force with more information then they need. If you can show them how their job applies to the five core functions, along with using VPP to change their safety culture, you will build a work force that will set the standards for doing work safely. Using INEEL's experience, this paper focuses on input from the work force and the culture necessary to implement ISM.
Date: May 1, 1999
Creator: Fox, David Harold & Hein, Curt David
System: The UNT Digital Library
3D unstructured mesh ALE hydrodynamics with the upwind discontinuous galerkin method (open access)

3D unstructured mesh ALE hydrodynamics with the upwind discontinuous galerkin method

The authors describe a numerical scheme to solve 3D Arbitrary Lagrangian-Eulerian (ALE) hydrodynamics on an unstructured mesh using a discontinuous Galerkin method (DGM) and an explicit Runge-Kutta time discretization. Upwinding is achieved through Roe's linearized Riemann solver with the Harten-Hyman entropy fix. For stabilization, a 3D quadratic programming generalization of van Leer's 1D minmod slope limiter is used along with a Lapidus type artificial viscosity. This DGM scheme has been tested on a variety of hydrodynamic test problems and appears to be robust making it the basis for the integrated 3D inertial confinement fusion modeling code (ICF3D). For efficient code development, they use C++ object oriented programming to easily separate the complexities of an unstructured mesh from the basic physics modules. ICF3D is fully parallelized using domain decomposition and the MPI message passing library. It is fully portable. It runs on uniprocessor workstations and massively parallel platforms with distributed and shared memory.
Date: May 7, 1999
Creator: Kershaw, D S; Milovich, J L; Prasad, M K; Shaw, M J & Shestakov, A I
System: The UNT Digital Library
Field-Measured Oxidation Rates of Biologically Reduced Selenium in Sludge (open access)

Field-Measured Oxidation Rates of Biologically Reduced Selenium in Sludge

Sludge generated during surface-water transport or biological treatment of selenium laden agricultural drainage water contains high concentrations (20-100 mg/kg) of selenium. Finding safe and economical sludge disposal methods requires understanding of the biogeochemical processes that change selenium speciation (after placed at a disposal site). Two experiments, each comparing 3 treatments for sludge disposal has resulted in data on changes in selenium speciation spanning an eight year period. Treatments included direct application to upland soils and application with tillage to depths of 15 cm and 30 cm. Soil cores, soil water samples and groundwater monitoring were used to track changes in selenium speciation and transport of re-oxidized forms of selenium. Measurements demonstrate the slow re-oxidation of reduced forms of selenium, largely elemental and organically associated forms, to selenate and selenite. Downward transport of these re-oxidized forms of selenium are driven by winter rains. Field measured re-oxidation rates for these field trials are presented and compared to selenium re-oxidation rates in formerly ponded areas at Kesterson Reservoir, California.
Date: May 1, 1999
Creator: Benson, Sally M.; Daggett, John & Zawislansi, Peter
System: The UNT Digital Library
Generating Self-Reliant Teams of Autonomous Cooperating Robots: Desired design Characteristics (open access)

Generating Self-Reliant Teams of Autonomous Cooperating Robots: Desired design Characteristics

The difficulties in designing a cooperative team are significant. Several of the key questions that must be resolved when designing a cooperative control architecture include: How do we formulate, describe, decompose, and allocate problems among a group of intelligent agents? How do we enable agents to communicate and interact? How do we ensure that agents act coherently in their actions? How do we allow agents to recognize and reconcile conflicts? However, in addition to these key issues, the software architecture must be designed to enable multi-robot teams to be robust, reliable, and flexible. Without these capabilities, the resulting robot team will not be able to successfully deal with the dynamic and uncertain nature of the real world. In this extended abstract, we first describe these desired capabilities. We then briefly describe the ALLIANCE software architecture that we have previously developed for multi-robot cooperation. We then briefly analyze the ALLIANCE architecture in terms of the desired design qualities identified.
Date: May 1, 1999
Creator: Parker, L. E.
System: The UNT Digital Library
Subcritical Measurements Research Program for Fresh and Spent Materials Test Reactor Fuels (open access)

Subcritical Measurements Research Program for Fresh and Spent Materials Test Reactor Fuels

'A series of subcritical noise measurements were performed on fresh and spent University of Missouri Research Reactor fuel assemblies. These experimental measurements were performed for the purposes of providing benchmark quality data for validating transport theory computer codes and nuclear cross-section data used to perform criticality safety analyses for highly enriched, uranium-aluminum Material Test Reactor fuel assemblies. A mechanical test rig was designed and built to hold up to four fuel assemblies and neutron detectors in a subcritical array. The rig provided researchers with the ability to evaluate the reactivity effects of variable fuel/detector spacing, fuel rotation, and insertion of metal reflector plates into the lattice.'
Date: May 13, 1999
Creator: Blanchard, A.
System: The UNT Digital Library
Novel interferometer spectrometer for sensitive stellar radial velocimetry (open access)

Novel interferometer spectrometer for sensitive stellar radial velocimetry

We describe a new kind of stellar radial velocimeter based on the series combination of a wide angle Michelson interferometer and a disperser, and which we call a fringing spectrometer. The simplest instrument response of the interferometer produces smaller instrumental noise, and the low resolution requirements of the disperser allows high efficiency and creates an etendue capability which is two orders of magnitude larger than current radial velocimeters. The instrument is compact, inexpensive and portable. Benchtop tests of an open-air prototype shows the short term instrumental noise to be less than 0.76 m/s. A preliminary zero point drift of 4 m/s is already competitive with traditional instruments, in spite of the lack of obvious environmental controls and a known interferometer cavity length drift. We are currently installing cavity stabilization and other improvements that will lead to testing on starlight.
Date: May 20, 1999
Creator: Erskine, D & Ge, J
System: The UNT Digital Library
Leaking electricity in domestic appliances (open access)

Leaking electricity in domestic appliances

Many types of home electronic equipment draw electric power when switched off or not performing their principal functions. Standby power use (or ''leaking electricity'') for most appliances ranges from 1 - 20 watts. Even though standby use of each device is small, the combined standby power use of all appliances in a home can easily exceed 50 watts. Leaking electricity is already responsible for 5 to 10 percent of residential electricity use in the United States and over 10 percent in Japan. An increasing number of white goods also have standby power requirements. There is a growing international effort to limit standby power to around one watt per device. New and existing technologies are available to meet this target at little or no extra cost.
Date: May 1, 1999
Creator: Meier, Alan & Rosen, Karen
System: The UNT Digital Library
The Secure, Transportable, Autonomous Reactor System (open access)

The Secure, Transportable, Autonomous Reactor System

The Secure, Transportable, Autonomous Reactor (STAR) system is a development architecture for implementing a small nuclear power system, specifically aimed at meeting the growing energy needs of much of the developing world. It simultaneously provides very high standards for safety, proliferation resistance, ease and economy of installation, operation, and ultimate disposition. The STAR system accomplishes these objectives through a combination of modular design, factory manufacture, long lifetime without refueling, autonomous control, and high reliability.
Date: May 27, 1999
Creator: Brown, N.W.; Hassberger, J.A.; Smith, C.; Carelli, M.; Greenspan, E.; Peddicord, K.L. et al.
System: The UNT Digital Library
Direct chemical oxidation of mixed or toxic wastes (open access)

Direct chemical oxidation of mixed or toxic wastes

Direct Chemical Oxidation (DCO) is an ambient-pressure, low-temperature (<100 C), and aqueous-based process for general-purpose destruction of the organic fraction of hazardous or mixed waste. It uses the peroxydisulfate anion (S{sub 2}O{sub 8}{sup 2{minus}}) in acid or base solutions. The byproduct of the oxidation reaction, typically sodium or ammonium hydrogen sulfate, may be recycled electrolytically to produce the oxidant. The oxidation kinetic reaction is first order with respect to the peroxydisulfate concentration, expressed in equivalents. The rate constant is constant for nearly all dissolved organic compounds: k{sub a} = 0.01 {+-} 0.005 min{sup {minus}1}. This reflects a common rate-determining step, which is the decomposition of the peroxydisulfate anion into the chemically active derivative, the sulfate radical anion, SO{sub 4}{sup {minus}}. This decomposition is promoted in DCO by raising the operating temperature into the range of 80-100 C. Rates are given for approximately 30 substances with diverse functional groups at low concentrations, and for a number of solid and liquid wastes typical of nuclear and chemical industries. The process has been scale up for treatment studies on chlorinated hydrocarbons, in which the hydrolysis of solvent mixtures was followed by oxidation of products in a series of stirred tank reactors. Cost estimates, …
Date: May 1, 1999
Creator: Balazs, G B; Cooper, J F; Farmer, J C & Lewis, P
System: The UNT Digital Library
Directions for advanced use of nuclear power in century XXI (open access)

Directions for advanced use of nuclear power in century XXI

Nuclear power can provide a significant contribution to electricity generation and meet other needs of the world and the US during the next century provided that certain directions are taken to achieve its public acceptance. These directions include formulation of projections of population, energy consumption, and energy resources over a responsible period of time. These projections will allow assessment of cumulative effects on the environment and on fixed resources. Use of fossil energy resources in a century of growing demand for energy must be considered in the context of long-term environmental damage and resource depletion. Although some question the validity of these consequences, they can be mitigated by use of advanced fast reactor technology. It must be demonstrated that nuclear power technology is safe, resistant to material diversion for weapon use, and economical. An unbiased examination of all the issues related to energy use, especially of electricity, is an essential direction to take.
Date: May 1, 1999
Creator: Walter, C E
System: The UNT Digital Library
High energy x-ray radiography and computed tomography of bridge pins (open access)

High energy x-ray radiography and computed tomography of bridge pins

Bridge pins were used in the hanger assemblies for some multi-span steel bridges built prior to the 1980's, and are sometimes considered fracture critical elements of a bridge. During a test on a bridge conducted by the Federal Highway Administration (FHWA), ultrasonic field inspection results indicated that at least two pins contained cracks. Several pins were removed and selected for further examination. This provided an excellent opportunity to learn more about these pins and the application of x-ray systems at Lawrence Livermore National Laboratory (LLNL), as well as to learn more about the application of different detectors recently obtained by LLNL. Digital radiographs and computed tomography (CT) were used to characterize the bridge pins, using a LINAC x-ray source with a 9-MV bremsstrahlung spectrum. We will describe the performance of two different digital radiographic detectors. One is a detector system frequently used at LLNL consisting of a scintillator glass optically coupled to a CCD camera. The other detector is a new amorphous silicon detector recently acquired by LLNL.
Date: May 1, 1999
Creator: Green, R E; Logan, C M; Martz, H E; Updike, E & Waters, A M
System: The UNT Digital Library
Polarization sensitive optical coherence tomography detection method (open access)

Polarization sensitive optical coherence tomography detection method

This study demonstrates the potential of polarization sensitive optical coherence tomography (PS-OCT) for non-invasive in vivo detection and characterization of early, incipient caries lesions. PS-OCT generates cross-sectional images of biological tissue while measuring the effect of the tissue on the polarization state of incident light. Clear discrimination between regions of normal and demineralized enamel is first shown in PS-OCT images of bovine enamel blocks containing well-characterized artificial lesions. High-resolution, cross-sectional images of extracted human teeth are then generated that clearly discriminate between the normal and carious regions on both the smooth and occlusal surfaces. Regions of the teeth that appeared to be demineralized in the PS-OCT images were verified using histological thin sections examined under polarized light microscopy. The PS-OCT system discriminates between normal and carious regions by measuring the polarization state of the back-scattered 1310 nm light, which is affected by the state of demineralization of the enamel. Demineralization of enamel increases the scattereing coefficient, thus depolarizing the incident light. This study shows that PS-OCT has great potential for the detection, characterization, and monitoring of incipient caries lesions.
Date: May 12, 1999
Creator: Everett, M J; Sathyam, U S; Colston, B W; DaSilva, L B; Fried, D; Ragadio, J N et al.
System: The UNT Digital Library
Self-effect in expanding electron beam plasma (open access)

Self-effect in expanding electron beam plasma

An analytical model of plasma flow from a metal plate hit by an intense, pulsed, electron beam aims to bridge the gap between radiation-hydrodynamics simulations and experiments, and to quantify the self-effect of the electron beam penetrating the flow. Does the flow disrupt the tight focus of the initial electron bunch, or later pulses in a train? This work aims to model the spatial distribution of plasma speed, density, degree of ionization, and magnetization to inquire. The initial solid density, several eV plasma expands to 1 cm and 10{sup {minus}4} relative density by 2 {micro}s, beyond which numerical simulations are imprecise. Yet, a Faraday cup detector at the ETA-II facility is at 25 cm from the target and observes the flow after 50 {micro}s. The model helps bridge this gap. The expansion of the target plasma into vacuum is so rapid that the ionized portion of the flow departs from local thermodynamic equilibrium. When the temperature (in eV) in a parcel of fluid drops below V{sub i} x [(2{gamma} - 2)/(5{gamma} + 17)], where V{sub i} is the ionization potential of the target metal (7.8 eV for tantalum), and {gamma} is the ratio of specific heats (5/3 for atoms), then …
Date: May 7, 1999
Creator: Garcia, M
System: The UNT Digital Library
Automated Acquisition and Analysis of Digital Radiographic Images (open access)

Automated Acquisition and Analysis of Digital Radiographic Images

'Engineers at the Savannah River Technology Center have designed, built, and installed a fully automated small field-of-view, lens-coupled, digital radiography imaging system. The system is installed in one of the Savannah River Site''s production facilities to be used for the evaluation of production components. Custom software routines developed for the system automatically acquire, enhance, and diagnostically evaluate critical geometric features of various components that have been captured radiographically. Resolution of the digital radiograms and accuracy of the acquired measurements approaches 0.001 inches. To date, there has been zero deviation in measurement repeatability. The automated image acquisition methodology will be discussed, unique enhancement algorithms will be explained, and the automated routines for measuring the critical component features will be presented. An additional feature discussed is the independent nature of the modular software components, which allows images to be automatically acquired, processed, and evaluated by the computer in the background, while the operator reviews other images on the monitor. System components were also a key in gaining the required image resolution. System factors such as scintillator selection, x-ray source energy, optical components and layout, as well as geometric unsharpness issues are considered in the paper. Finally the paper examines the numerous quality …
Date: May 13, 1999
Creator: Poland, R.
System: The UNT Digital Library
First Lasing of the Jefferson Lab IR Demo FEL (open access)

First Lasing of the Jefferson Lab IR Demo FEL

As reported previously [1], Jefferson Lab is building a free-electron laser capable of generating a continuous wave kilowatt laser beam. The driver-accelerator consists of a superconducting, energy-recovery accelerator. The initial stage of the program was to produce over 100 W of average power with no recirculation. In order to provide maximum gain the initial wavelength was chosen to be 5 mu-m and the initial beam energy was chosen to be 38.5 MeV. On June 17, 1998, the laser produced 155 Watts cw power at the laser output with a 98% reflective output coupler. On July 28th, 311 Watts cw power was obtained using a 90% reflective output coupler. A summary of the commissioning activities to date as well as some novel lasing results will be summarized in this paper. Present work is concentrated on optimizing lasing at 5 mu-m, obtaining lasing at 3 mu-m, and commissioning the recirculation transport in preparation for kilowatt lasing this fall.
Date: May 1, 1999
Creator: Benson, Stephen; Biallas, George; Bohn, Court; Douglas, David; Dylla, H.F.; Evans, R. et al.
System: The UNT Digital Library
One watt initiative: A global effort to reduce leaking electricity (open access)

One watt initiative: A global effort to reduce leaking electricity

Many domestic appliances and commercial equipment consume some electric power when they are switched off or not performing their primary purpose. The typical loss per appliance is low (from 1 to 25 W) but, when multiplied by the billions of appliances in houses and in commercial buildings, standby losses represent a significant fraction of total electricity use. Several initiatives to reduce standby losses have appeared in different parts of the world. One proposal, the 1-watt plan, seeks to harmonize these initiatives by establishing a single target for all appliances. This paper explains the background to the 1-watt plan, identifies some unresolved aspects, and gives some estimates of energy savings.
Date: May 30, 1999
Creator: Meier, Alan K. & LeBot, Benoit
System: The UNT Digital Library
Barriers to communication and cooperation in addressing community impacts of radioactive releases from research facilities. (open access)

Barriers to communication and cooperation in addressing community impacts of radioactive releases from research facilities.

Two instances of research facilities responding to public scrutiny will be discussed. The first concerns emissions from a �tritium labeling facility� operated at Lawrence Berkeley National Laboratory (LBNL); the second deals with releases of plutonium from Lawrence Livermore National Laboratory (LLNL). There are many parallels between these two cases, both of which are still ongoing. In both, the national laboratory is the acknowledged source of low-level (by regulatory standards) radioactive contamination in the community. A major purpose of both investigations is to determine the degree of the contamination and the threat it poses to public health and the environment. The examining panel or committee is similarly constituted in the two cases, including representatives from all four categories of stakeholders: decision makers; scientists and other professionals doing the analysis/assessment; environmental activist or public interest groups; and �ordinary� citizens (nearly everyone else not in one or more of the first three camps). Both involved community participation from the beginning. The levels of outrage over the events triggering the assessment are comparable; though �discovered� or �appreciated� only a few years ago, the release of radiation in both cases occurred or began occurring more than a decade ago. The meetings have been conducted in …
Date: May 5, 1999
Creator: Harrach, R J & Peterson, S
System: The UNT Digital Library
Overture: Object-Oriented Tools for Application with Complex Geometry (open access)

Overture: Object-Oriented Tools for Application with Complex Geometry

The Overture framework is an object-oriented environment for solving partial differential equations in two and three space dimensions. It is a collection of C++ libraries that enables the use of finite difference and finite volume methods at a level that hides the details of the associated data structures. Overture can be used to solve problems in complicated, moving geometries using the method of overlapping grids. It has support for grid generation, difference operators, boundary conditions, data-base access and graphics. Short sample code segments are presented to show the power of this approach.
Date: May 31, 1999
Creator: Brown, D.; Henshaw, B. & Quinlan, D.
System: The UNT Digital Library
Spin measurements in high -t exclusive photoreactions (open access)

Spin measurements in high -t exclusive photoreactions

The approximate validity of the constituent counting rules to few GeV photoreactions has been known for many years. It is now generally accepted that perturbative QCD, which leads to these rules, cannot be applicable in this low energy and momentum transfer regime. Cross section and polarization measurements now underway show promise to lead to the underlying physics. Initial experiments on deuteron photodisintegration and pion electroproduction are now in progress, and are expected to be followed by several other measurements.
Date: May 1, 1999
Creator: Gilman, Ron
System: The UNT Digital Library
The secure, transportable, autonomous reactor (STAR): a small proliferation-resistant reactor system for developing countries (open access)

The secure, transportable, autonomous reactor (STAR): a small proliferation-resistant reactor system for developing countries

The Secure, Transportable, Autonomous Reactor (STAR), is an integrated concept for a small, proliferation-resistant nuclear power system capable of meeting the growing power demands of many regions of the developing world. The STAR approach builds on earlier work investigating the features required for implementation of such a system. The STAR approach includes establishing overall system requirements, conducting research into issues common to four reactor concepts (gas, liquid metal, light water and molten salt), and defining and performing the down-selection to a preferred concept that will serve as the basis for continued development leading to an eventual prototype. The paper indicates that a number of unique and distinguishing innovations are needed to both meet the energy demands of most of the world's developing regions and address growing nuclear proliferation concerns. These technical innovations form much of the basis underlying the STAR concept and include: eliminating on-site refueling and fuel access; incorporating a systems approach to nuclear energy supply and infrastructure design, with all aspects of equipment life, fuel and waste cycles included; small unit size enabling transportability; replaceable standardized modular design; resilient and robust design concepts leading to large safety margins, high reliability and reduced maintenance; simplicity in operation with reliance …
Date: May 27, 1999
Creator: Brown, N W; Hassberger, J A & Smith, C F
System: The UNT Digital Library