Internal current densities and electric fields induced in the human body during exposure to EMP fields are reviewed and used to predict resulting cell membrane potentials. Using several different approaches, membrane potentials of about 100 mV are predicted. These values are comparable to the static membrane potentials maintained by cells as a part of normal physiological function, but the EMP-induced potentials persist for only about 10 ns. Possible biological implications of EMP-induced membrane potentials including conformational changes and electroporation are discussed.

The objectives of this project were to develop a novel type of candle filter based on a ceramic fiber-ceramic matrix composite material, and to extend the development to full-size, 60-mm OD by 1-meter-long candle filters. The goal is to develop a ceramic filter suitable for use in a variety of fossil energy system environments such as integrated coal gasification combined cycles (IGCC), pressurized fluidized-bed combustion (PFBC), and other advanced coal combustion environments. Further, the ceramic fiber ceramic matrix composite filter, hereinafter referred to as the ceramic composite filter, was to be inherently crack resistant, a property not found in conventional monolithic ceramic candle filters, such as those fabricated from clay-bonded silicon carbide. Finally, the adequacy of the filters in the fossil energy system environments is to be proven through simulated and in-plant tests.

The Oak Ridge National Laboratory (ORNL) is a large multipurpose US Department of Energy research facility located in East Tennessee on the Oak Ridge Reservation (ORR). The legacy of fifty years of operations at ORNL includes a variety of contaminated inactive facilities, research areas, and former waste disposal areas. At ORNL the majority of wastes were buried in shallow trenches above the water table. Groups of geographically contiguous areas, referred to as waste area groupings (WAGs), were defined for the Environmental Restoration Program so that a suitable monitoring system could be established. Thirteen WAGs at ORNL have been identified as potential sources of groundwater contamination. The main objective of the work described in this paper was to develop a systematic means for analyzing routine groundwater monitoring data from all WAGs to facilitate interpretation at a scale larger than individual monitoring points, to look for patterns that suggest general principles. In particular we wanted to determine whether specific geologic formations have discernable groundwater chemical signatures. The description of geologic formations in terms of their groundwater chemical signatures can be used in several practical ways. Positioning of down gradient sampling locations can be evaluated by comparing contaminant source and down gradient geochemistries. …

We present results on charmonium production, b quark and B meson production and B{bar B} correlations using data taken with the CDF detector at Fermilab in p{bar p} collisions at {radical}s = 1.8 TeV during the 1992--1993 collider run.

This paper reviews the development of the field of chemical analysis of biomass fast pyrolysis oils. The techniques applied to pyrolysis oil analysis are reviewed including proximate and ultimate analysis, water (moisture) analysis, and chemical component analysis by various forms of chromatography, solvent separations, and spectrophotometric analyses, like infrared and ultraviolet. Advanced analytical techniques such as nuclear magnetic resonance and molecular beam -- mass spectrometry are also discussed. This paper reviews and compares the methods and the results of the analyses. The advantages and shortcomings of the various methods applied are identified. Comparisons derived from the IEA Round Robin are incorporated.

For waste containing small amounts of radioactivity, rad waste (RW), or mixed waste (MW) containing both radioactive and chemically hazardous components, incineration is a logical management candidate because of inherent safety, waste volume reduction, and low costs. Successful operation requires that the facility is properly designed and operated to protect workers and to limit releases of hazardous materials. The large decrease in waste volume achieved by incineration also results in a higher concentration of most of the radionuclides and non radioactive heavy metals in the ash products. These concentrations impact subsequent treatment and disposal. The various constituents (chemical elements) are not equal in concentration in the various incinerator feed materials, nor are they equal in their contribution to health risks on subsequent handling, or accidental release. Thus, for management of the wastes it is important to be able to predict how the nuclides partition between the primary combustion residue which may be an ash or a fused slag, the fine particulates or fly ash that is trapped in the burner off-gas by several different techniques, and the airborne fraction that escapes to the atmosphere. The objective of this report is to provide an estimate of how different elements of concern …

In the foreseeable future, an expedition may be undertaken to explore the planet Mars. Some of the power source options being considered for such a mission are photovoltaics, regenerative fuel cells and nuclear reactors. In addition to electrical power requirements, environmental conditions en route to Mars, in the planetary orbit and on the Martian surface must be simulated and studied in order to anticipate and solve potential problems. Space power systems components such as photovoltaic arrays, radiators, and solar concentrators may be vulnerable to degradation in the Martian environment. Natural characteristics of Mars which may pose a threat to surface power systems include high velocity winds, dust, ultraviolet radiation, large daily variations in temperature, reaction to components of the soil, atmosphere and atmospheric condensates as well as synergistic combinations. Most of the current knowledge of the characteristics of the Martian atmosphere and soil composition was obtained from the Viking 1 and 2 missions in 1976. This paper presents a theoretical study used to assess the effects of the Martian atmospheric conditions on the power systems components. A computer program written at NASA Lewis Research Center in 1961 to 1962 for combustion research that uses a free-energy minimization technique was used …

At the Department of Energy`s (DOE`s) Oak Ridge National Laboratory (ORNL) a unique closure was accomplished for a storage canal that contained both hazardous chemical contaminants controlled by the Resource Conservation and Recovery Act (RCRA), and radioactive contaminants controlled by the Atomic Energy Act (AEA). During 1991 and 1992, after approvals were received from the DOE and the Tennessee Department of Environment and Conservation (TDEC), subcontractors to DOE`s Construction Manager were mobilized and remote controlled equipment was operated on site to remove the RCRA and radioactive contamination (referred to hereafter as mixed wastes) from the 3001 Storage Canal at ORNL. After numerous {open_quotes}surprises{close_quotes} during the removal activities, each requiring problem resolution and approvals from DOE and TDEC, the canal closure was completed in September 1992 and final closure certification was submitted to TDEC in October 1992. The following discussion describes the learning experiences that ORNL and DOE acquired from a RCRA closure project for a mixed waste storage canal containing high radiation levels. The project was successful, especially since worker exposures were minimized, but was lengthy, requiring 30 months from notification of a leak in the canal until final demobilization of the subcontractor, and expensive to complete (total overall cost …

This paper compares reported dynamic analyses for evaluating the steady-state response and stability of free-piston Stirling engine (FPSE) systems. Various analytical approaches are discussed to provide guidance on their salient features. Recommendations are made in the recommendations remarks for an approach which captures most of the inherent properties of the engine. Such an approach has the potential for yielding results which will closely match practical FPSE-load systems.

Synroc C waste form specimens prepared using the Australian-developed technology are uniaxially pressed in stainless steel bellows at 1200{degrees}C and 20MPa. This produces a material with high chemical and physical durability and with the radioactivity enclosed inside both the waste form and the bellows. An alternative method of producing the ceramic product is to use cold pressing of pellets followed by reactive sintering to provide densification and mineralization. Depending on the scale of waste form preparation required and on the activity level and nature of the waste streams, the cold press and sinter method may have advantages. To evaluate the effects of production method on waste form characteristics, especially resistance to dissolution or leaching of waste elements, we have prepared two simulated waste samples for evaluation. Both samples were prepared from liquid precursor materials (alkoxides, nitrates, and colloidal silica) and then doped with waste elements. The precursor material in each case corresponded to a basic phase assemblage of 60% zirconolite, 15% nepheline, 10% spinel, 10% perovskite, and 5% rutile. One sample was doped with 25% by weight of U; the other with 10% by weight each of U and Gd. Each sample was calcined at 750{degrees}C for 1 hr. in …

Scenarios and computer codes used to evaluate intrusion scenarios at different DOE sites are compared and discussed. The purpose of the comparison is to identify differences in the approaches and areas where approaches could be made more consistent without ignoring the need to consider legimate site-specific differences, The comparison is comprised of two steps: (1) benchmarking of CENII and PATHRAE (the two most commonly used codes at DOE sites), and (2) comparison of assumed values for selected input parameters from:scenarios used at the different sites. The results of the benchmarking and parameter comparisons identify fundamental differences in the default assumptions used in the computer codes, as well as differences in the approaches used at the different sites. GENII and PATHRAE are applied to a variety of sites within DOE and other regulatory environments, differences in default assumptions identified in these comparisons are discussed for users to consider when they apply the codes. Furthermore, differences in assumptions made at the different sites disposing of low-level radioactive wastes within Department of Energy are identified to provide an example of how the Performance Assessment Task Team is working to ensure consistent interpretation of performance assessment results.

The availability of experimental data that characterizes the performance of soft magnetic materials for the combined conditions of high temperature and high frequency is almost non-existent. An experimental investigation was conducted over the temperature range of 23 to 300 C and frequency range of 1 to 50 kHz to determine the effects of temperature and frequency on the core loss and dynamic B-H loops of three different soft magnetic materials; an oriented-grain 50Ni-50Fe alloy, a nonoriented-grain 50Ni-50Fe alloy, and an iron-based amorphous material (Metglas 2605SC). A comparison of these materials show that the nonoriented-grain 50Ni-50Fe alloy tends to have either the lowest or next lowest core loss for all temperatures and frequencies investigated.

The collision and subsequent interaction of counter-streaming plasmas occurs in several areas of laser-plasma research including double foil targets for x-ray lasers and the plasma blow-off inside ICF hohlraums. Because a single fluid model allows for only one value of the flow velocity at any one spatial location, interpenetration of the plamas is not allowed resulting in immediate stagnation with complete conversion of the ion-streaming kinetic energy to thermal energy. Multifluid models have been developed which employ multiple ion fluid species that interact through the self-consistent electrostatic field and collisional coupling. Because they are approximations to a kinetic situation, the form of these coupling coefficients is not unique, with various workers using differing approximations. More recently, Larroche has implemented a finite difference approach to the ion Fokker-Planck equation while Jones and co-workers have performed two-dimensional simulations of colliding plasmas using a particle-in-cell code with a new collisional model. Our kinetic modeling also makes use of particle in cell (PIC) techniques with Monte Carlo (MC) particle-particle collisions algorithm that is equivalent to the Fokker-Planck collision operator. We have made direct comparison of this MC-PIC model to multifluid simulations on both simple slowing-down and equilibration problems as well as problems characteristic of …

Using an operator form of a synthetic acceleration method, we derive the P{sub 1}- and a new second-moment P{sub 2}-acceleration schemes. We analyze the convergence rate of each scheme by Performing a Fourier analysis. The second-moment P{sub 2}-acceleration outperforms an earlier third-moment P{sub 2}-acceleration method by Miller and Larsen. However, it is still less efficient than P{sub l}-acceleration (diffusion synthetic acceleration: DSA). These results confirm that one cannot simply assume that replacement of the DSA method with a higher order operator will lead to a smaller spectral radius. We get similar results for the P{sub l}- and simplified P{sub 2}-acceleration in two-dimensional x-y geometry.

Two monolithic silicon carbides, NT230 siliconized SiC from Norton Saint Gobain and sintered {beta}-SiC from Coors, and a silicon carbide particulate reinforced alumina ceramic composite from Lanxide, which all are candidate materials for pressurized heat exchangers in coal-fired power plants have been evaluated. The fast fracture flexure strength was measured as a function of temperature. All candidate materials retained a sufficient strength level up to 1400C. The susceptibility to slow crack growth (SCG) was evaluated by the dynamic fatigue method at 1100C and 1400C. None of the materials exhibited SCG at 1100C. At 1400C the siliconized SiC ceramic showed limited SCG and the composite ceramic exhibited creep damage when stressed to 50% of fast fracture strength at the intermediate and slow stressing rates. This prevented the evaluation of the SCG properties of this material at 1400C. Fractography supported the mechanical observations and with the exception of the specimens which exhibited creep damage, only the siliconized SiC showed a small SCG damage zone at long times at 1400C.

The first circuit results for a new GaAs complementary logic technology are presented. The technology allows for Independently optimizable p- and n- channel transistors with junction gates. Excellent loaded gate delays of 179 ps at 1.2 V and 319 ps at 0.8 V have been demonstrated at low power supply voltages. A power-delay product of 8.9 fJ was obtained at 0.8 V.

In the first of these lectures, the experimental emission probabilities of complex fragments by low energy compound nuclei and their dependence upon energy and Z value are compared to the transition state rates. In the second part, the high energy multi-fragment emission probabilities are shown to be reducible to the single fragment emission probability through the binomial distribution. The extracted one-fragment emission probabilities have a thermal dependence of the form p = e{sup {minus}B/T}. This suggests that multifragmentation is a sequence of thermal binary decays.

The authors are working to understand why predictions of degradation behaviors and rates, based on accelerated thermal aging experiments, often fail to match with aging of polymers under service conditions. A main goal of these studies is to develop more reliable lifetime prediction methodologies.

NASA Lewis Research Center has organized a component technology program as part of the efforts to develop Stirling converter technology for space power applications. The Stirling space power program is part of the NASA High Capacity Power Project of the Civil Space Technology Initiative (CSTI). NASA Lewis is also providing technical management for a DOE/Sandia program to develop Stirling converters for solar terrestrial power producing electricity for the utility grid. The primary contractors for the space power and solar terrestrial programs develop component technologies directly related to their program goals. This Lewis component technology effort, while coordinated with the main programs, aims at longer term issues, advanced technologies, and independent assessments. This paper will present an overview of work on linear alternators, engine/alternator/load interactions and controls, heat exchangers, materials, life and reliability, and bearings.

A combined theoretical and experimental effort to model various physical processes during laser ablation of solids (silicon) using a variety of computational techniques is described. Currently the focus of the modeling is on the following areas: (a) rapid transformations through the liquid and vapor phases under possibly nonequilibrium thermodynamic conditions induced by laser-solid interactions, (b) breakdown of the vapor into a plasma in the early stages of ablation through both electronic and photoionization processes, (c) hydrodynamic behavior of the vapor/plasma during and after ablation, and (d) effects of initial conditions in the vapor, in particular, the nature of the initial velocity distribution, on the characteristics of subsequent vapor expansion. Results from the modeling are compared with experimental observations where possible.

Resolution matrices are useful in seismic tomography because they allow us to evaluate the information content of reconstructed images. Techniques based on the multiplicity of equivalent exact formulas that may be used to define the resolution matrices have been used previously by the author to design algorithms that avoid the need for any singular value decomposition of the ray-path matrix. An explicit procedure is presented for computing both model and data resolution matrices using Arnoldi`s algorithm for iterative inversion in seismic tomography. Arnoldi`s method differs from the Lanczos scheme by including explicit reorthogonalization of basic vectors. Some convenient notation is introduced to permit ready comparison of Arnoldi`s method with the Lanczos approach. Arnoldi`s method requires greater storage of basic vectors but completely overcomes the lack of basis vector orthogonality, which is the major practical limitation of the Lanczos method.

A spallation target constructed of thorium metal has been designed for applications using molten-salt as the target coolant. The design consists of an array of wire-wrapped, hastelloy-clad, thorium rods in which a parabolic void region is introduced in the upper regions. Each target rod is approximately 1 m in length, 3.1 an in diameter, and has a clad thickness of 0.05 cm; 140 rods are arranged in a triangular lattice with a pitch of 3.2 cm, which results in a cylindrical target configuration with a radius of 20 cm and an estimated yield of 17 neutrons/proton 800 MeV protons.

None

Although the majority of top coatings used for corrosion protection are electrically insulating, previous workers have proposed using an electrically active barrier for corrosion control. The most effective corrosion resistant undercoatings in use today are based on chromium compounds. Coatings based on other materials will need to replace these coatings by the turn of the century because of environmental and health concerns. For this reason the authors have begun an investigation of the use of conducting polymers as corrosion resistant coatings as an alternative to metal-based coatings. Conducting polymers have long been considered to be unsuitable for commercial processing, hindering their use for practical applications. Research in the field of electrically conducting polymers has recently produced a number of polymers such as polyaniline and its derivatives which are readily soluble in common organic solvents. The authors coating system, consisting of a conducting polyaniline primer layer, topcoated with epoxy or polyurethane, has been evaluated for corrosion resistance on mild steel substrates. In this paper, the authors report the results of laboratory testing under acidic and saline conditions and the results of testing in the severe launch environment at the Beach Testing Facility at Kennedy Space Center. The launch environment consists of …