Graphical user interface for AMOS and POISSON (open access)

Graphical user interface for AMOS and POISSON

A graphical user interface (GUI) exists for building model geometry for the time-domain field code, AMOS. This GUI has recently been modified to build models and display the results of the Poisson electrostatic solver maintained by the Los Alamos Accelerator Code Group called POISSON. Included in the GUI is a 2-D graphic editor allowing interactive construction of the model geometry. Polygons may be created by entering points with the mouse, with text input, or by reading coordinates from a file. Circular arcs have recently been added. Once polygons are entered, points may be inserted, moved, or deleted. Materials can be assigned to polygons, and are represented by different colors. The unit scale may be adjusted as well as the viewport. A rectangular mesh may be generated for AMOS or a triangular mesh for POISSON. Potentials from POISSON are represented with a contour plot and the designer is able to mouse click anywhere on the model to display the potential value at that location. This was developed under the X windowing system using the Motif look and feel.
Date: March 2, 1993
Creator: Swatloski, T. L.
System: The UNT Digital Library
Dual-band infrared capabilities for imaging buried object sites (open access)

Dual-band infrared capabilities for imaging buried object sites

We discuss dual-band infrared (DBIR) capabilities for imaging buried object sizes. We identify physical features affecting thermal contrast needed to distinguish buried object sites from undisturbed sites or surface clutter. Apart from atmospheric transmission and system performance, these features include: object size, shape, and burial depth; ambient soil, disturbed soil and object site thermal diffusivity differences; surface temperature, emissivity, plant-cover, slope, albedo and roughness variations; weather conditions and measurement times. We use good instrumentation to measure the time-varying temperature differences between buried object sites and undisturbed soil sites. We compare near surface soil temperature differences with radiometric infrared (IR) surface temperature differences recorded at 4.7 {plus_minus} 0.4 {mu}m and at 10.6 {plus_minus} 1.0 {mu}m. By producing selective DBIR image ratio maps, we distinguish temperature-difference patterns from surface emissivity effects. We discuss temperature differences between buried object sites, filled hole site (without buried objects), cleared (undisturbed) soil sites, and grass-covered sites (with and without different types of surface clutter). We compare temperature, emissivity-ratio, visible and near-IR reflectance signatures of surface objects, leafy plants and sod. We discuss the physical aspects of environmental, surface and buried target features affecting interpretation of buried targets, surface objects and natural backgrounds.
Date: April 2, 1993
Creator: Del Grande, N. K.; Durbin, P. F.; Gorvad, M. R.; Perkins, D. E.; Clark, G. A.; Hernandez, J. E. et al.
System: The UNT Digital Library
Regenerative fuel cells for High Altitude Long Endurance Solar Powered Aircraft (open access)

Regenerative fuel cells for High Altitude Long Endurance Solar Powered Aircraft

High Altitude Long Endurance (HALE) unmanned missions appear to be feasible using a lightweight, high efficiency, span-loaded, Solar Powered Aircraft (SPA) which includes a Regenerative Fuel Cell (RFC) system and novel tankage for energy storage. An existing flightworthy electric powered flying wing design was modified to incorporate present and near-term technologies in energy storage, power electronics, aerodynamics, and guidance and control in order to design philosophy was to work with vendors to identify affordable near-term technological opportunities that could be applied to existing designs in order to reduce weight, increase reliability, and maintain adequate efficiency of components for delivery within 18 months. The energy storage subsystem for a HALE SPA is a key driver for the entire vehicle because it can represent up to half of the vehicle weight and most missions of interest require the specific energy to be considerably higher than 200 W-hr/kg for many cycles. This stringent specific energy requirement precludes the use of rechargeable batteries or flywheels and suggests examination of various RFC designs. An RFC system using lightweight tankage, a single fuel cell (FC) stack, and a single electrolyzer (EC) stack separated by the length of a spar segment (up to 39 ft), has specific …
Date: June 2, 1993
Creator: Mitlitsky, F.; Colella, N. J.; Myers, B. & Anderson, C. J.
System: The UNT Digital Library
Nuclear weapons issues in South Asia (open access)

Nuclear weapons issues in South Asia

This report discusses how the US can play a productive mediating role in South Asia by engaging India and Pakistan in an international forum to manage nuclear weapons, as Edward Teller advocated. India and Pakistan have developed their nuclear capabilities because they fear their neighbors, not because they want to threaten fear their neighbors, not because they want to threaten the US. The appropriate response for the US, therefore, is diplomatic engagement and negotiations. In addition to the international approach, encouragement and facilitation of regional and bilateral interactions will also be important. Formal arms control agreements have been reached, but less formal confidence-building measures, and unilateral security pledges may well be combined to form a more secure strategic environment in South Asia than a nuclear armed confrontation across the porous South Asian border.
Date: July 2, 1993
Creator: Joeck, N.
System: The UNT Digital Library
Dealing with the chlorinated solvent situation at the Oak Ridge Y-12 Plant (open access)

Dealing with the chlorinated solvent situation at the Oak Ridge Y-12 Plant

Recent events regarding health and environmental problems associated with the use of chlorinated solvents have prompted the Oak Ridge Y-12 Plant to investigate substitutes for these materials. Since 1987, the purchase of chlorinated solvents at the Y-12 Plant has been reduced by 92%. This has been accomplished by substituting chlorinated solvent degreasing with ultrasonic aqueous detergent cleaning and by substituting chlorinated solvents with less toxic, environmentally friendly solvents for hand-wiping applications. Extensive studies of cleaning ability, compabitility, and effects on welding, bonding, and painting have been conducted to gain approval for use of these solvents. Toxicity and waste disposal were also assessed for the solvents.
Date: August 2, 1993
Creator: Thompson, L. M. & Simandl, R. F.
System: The UNT Digital Library
Economics of electron beam and electrical discharge processing for post-combustion NO{sub x} control in internal combustion engines (open access)

Economics of electron beam and electrical discharge processing for post-combustion NO{sub x} control in internal combustion engines

This paper discusses the physics and chemistry of non-thermal plasma processing for post-combustion NO{sub x} control in internal combustion engines. A comparison of electron beam and electrical discharge processing is made regarding their power consumption, radical production, NO{sub x} removal mechanisms, and by-product formation. Pollution control applications present a good opportunity for transferring pulsed power techniques to the commercial sector. However, unless advances are made to drastically reduce the price and power consumption of electron beam sources and pulsed power systems, these plasma techniques will not become commercially competitive with conventional thermal or surface-catalytic methods.
Date: August 2, 1993
Creator: Penetrante, B. M.
System: The UNT Digital Library
Improved measurement accuracy in a Long Trace Profiler: Compensation for laser pointing instability (open access)

Improved measurement accuracy in a Long Trace Profiler: Compensation for laser pointing instability

Laser pointing instability adds to the error of slope measurements taken with the Long Trace Profiler (LTP). As with carriage pitch error, this laser pointing error must be accounted for and subtracted from the surface under test (SUT) slope measurement. In the past, a separate reference beam (REF) allowed characterization of the component of slope error from carriage pitch. However, the component of slope error from laser pointing manifests itself differently in the SUT measured slope. An analysis of angle error propagation is given, and the effect of these errors on measured slope is determined. Then a method is proposed for identifying these errors and subtracting them from the measured SUT slope function. Separate measurements of carriage pitch and laser pointing instability isolate these effects, so that the effectiveness of the error identification algorithm may be demonstrated.
Date: August 2, 1993
Creator: Irick, S. C.
System: The UNT Digital Library
Analytic properties of the OCP and ionic mixtures in the strongly coupled fluid state (open access)

Analytic properties of the OCP and ionic mixtures in the strongly coupled fluid state

Exact results for the Madelung constants and first order anharmonic energies are given for the inverse power potentials with the Coulomb potential as the softest example. Similar exact results are obtained using the analysis of Rosenfeld on the {Gamma} {yields} {infinity} limit for the OCP internal energy, direct correlation function, screening function, and bridge functions. Knowing these exact limits for the fluid phase of the OCP allows one to determine the nature of the thermal corrections to the strongly coupled results. Solutions of the HNC equation modified with the hard sphere bridge function give an example.
Date: December 2, 1993
Creator: DeWitt, H. E.
System: The UNT Digital Library
Overview of the Chemical Weapons Convention (open access)

Overview of the Chemical Weapons Convention

My subject this morning is a very brief overview of the Chemical Weapons Convention. Much has already been written describing and summarizing the Convention, including several of the Supplementary Papers and the Annex contained within the draft Manual. It is not my goal to restate what many of you already know. Rather, in the short time available, I want to focus on the parts of the Convention that are addressed in the draft Manual, that is, I want to highlight for you those aspects of the CWC that require implementation by individual State Parties. As I do so, I will show you where in the draft Manual each of these matters is addressed so that you can see how our document corresponds to the Convention`s requirements. This will provide a bridge between the plenary sessions and workshops that will consider the implementing measures and the Supplementary Papers in the Manual. In organizing my talk to focus on aspects of the Convention requiring national implementing measures, I necessarily leave out certain of its provisions. Among these intentional omissions are, with all due respect to our hosts, the structure and function of the OPCW, the Annex on Chemicals, and various operational aspects …
Date: December 2, 1993
Creator: Tanzman, E. A.
System: The UNT Digital Library
Strongly coupled ionic mixtures and the H/He EOS (open access)

Strongly coupled ionic mixtures and the H/He EOS

This paper summarizes recent work on the strongly coupled OCP and Binary Ionic Mixture equation of state and other thermodynamic quantities in white dwarf interior conditions for both fluid and solid phases with the assumption of a uniform background. Conditions for phase separation of different elements in fluid or solid phases is strongly dependent on deviations from the linear mixing rule which gives the equation of state as an additive function of the OCP equation of state. These deviations turn out to be small (a few parts in 10{sup 5}) and always positive including the case where the fraction of the higher Z component approaches 0. Also the equation of state of strongly coupled light elements (H and He particularly) obtained from simulations with a linear response description of the electrons is given for conditions appropriate to brown dwarf star interiors. Recent Livermore work on a band structure calculation of the enthalpy of H and He mixtures under jovian conditions is discussed. This work leads to a prediction of a high temperature (15,000 K) for miscibility of He in ionized H at 10 Mb.
Date: December 2, 1993
Creator: DeWitt, H. E.
System: The UNT Digital Library