Geometric, kinetic, and trapping issues, in short and ultrashort recombination x-ray lasers, are discussed. The design of a composite target consisting of a lasant strip on a plastic backing is described. Examples of modeling showing the effect of photon trapping and uncertainties in other physical processes on calculated gain coefficients are given. A simple and accurate expression for photon trapping in cylindrical geometry is presented. Recombination lasers that have the ground state as the lower laser state are shown to have small I{sub sat}'s and corresponding low efficiencies. Scaling laws for femtosecond laser-plasma interactions are presented. 19 refs.

We construct discrete space-time coordinates separated by the Lorentz-invariant intervals h/mc in space and h/mc{sup 2} in time using discrimination (XOR) between pairs of independently generated bit-strings; we prove that if this space is homogeneous and isotropic, it can have only 1, 2 or 3 spacial dimensions once we have related time to a global ordering operator. On this space we construct exact combinatorial expressions for free particle wave functions taking proper account of the interference between indistinguishable alternative paths created by the construction. Because the end-points of the paths are fixed, they specify completed processes; our wave functions are born collapsed''. A convenient way to represent this model is in terms of complex amplitudes whose squares give the probability for a particular set of observable processes to be completed. For distances much greater than h/mc and times much greater than h/mc{sup 2} our wave functions can be approximated by solutions of the free particle Dirac and Klein-Gordon equations. Using a eight-counter paradigm we relate this construction to scattering experiments involving four distinguishable particles, and indicate how this can be used to calculate electromagnetic and weak scattering processes. We derive a non-perturbative formula relating relativistic bound and resonant state energies …

Coal Production 1989 provides comprehensive information about US coal production, the number of mines, prices, productivity, employment, reserves, and stocks to a wide audience including Congress, federal and state agencies, the coal industry, and the general public. 7 figs., 43 tabs.

Peak bare-surface current densities based on the scratched electrode test are seriously in error and repasivation rates grossly overestimated. Influences of potential and pH on reactions of bare surfaces are better understood. Correlation between charge transfer and corrosion fatigue crack growth response was established for Fe18Cr12Ni alloy in deaerated 0.6N NaCl at RT. Strong correlation was established between morphology of corrosion fatigue fracture surfaces and cracking in hydrogen charged samples. Attempts at growing bicrystals by strain annealing were not successful.

Peak bare-surface current densities based on the scratched electrode test are seriously in error and repasivation rates grossly overestimated. Influences of potential and pH on reactions of bare surfaces are better understood. Correlation between charge transfer and corrosion fatigue crack growth response was established for Fe18Cr12Ni alloy in deaerated 0.6N NaCl at RT. Strong correlation was established between morphology of corrosion fatigue fracture surfaces and cracking in hydrogen charged samples. Attempts at growing bicrystals by strain annealing were not successful.

After the central calorimeter was installed on the center beam a cracked weld was found on the bridge. The weld was a partial penetration between the top rail plate and the T-1 steel nose section. The crack is fully across the width of the rail plate and the rail is depressed in a concave shape. That is, the depression is deeper in the center and feathers out to zero at the end of the rail. Upon close inspection it was obvious that there was no penetration of weld metal into the T-1 material. The assumption is that the T-1 was not properly pre-heated before welding. The reason for the concave depression comes from the fact that the rail plate rests on the flanges of the 'S' beams and that during welding the plate pulled off the beams. This weld failure can not propagate to any other welds and therefore, will not start a chain of failures. Clearly the failure of this weld did not hinder the installation of the central calorimeters. This weld failure occurred on both sides of the bridge. This failure did, however, alert us to check the critical weld on the bridge, S-beam webs to T-1 nose …

This report describes recent progress in a fundamental, three-year investigation of carbon formation and its effects on the activity and selectivity of promoted iron catalysts for synthesis, the objectives of which are: determine rates and mechanisms of carbon deactivation of unsupported Fe and Fe/K catalysts during CO hydrogenation over a range of CO concentrations, CO:H{sub 2} ratios, and temperatures; model the rates of deactivation of the same catalysts in fixed-bed reactors. During the fourteenth quarter design of software for a computer-automated reactor system to be used in the kinetic and deactivation studies was continued. Further progress was made toward the completion of the control language, control routines, and software for operating this system. Progress was also made towards testing of the system hardware and software. 47 refs.

The objective of proposed research is development of catalysts with enhanced slurry phase activity and better selectivity to fuel range products, through a more detailed understanding and systematic studies of the effects of pretreatment procedures and promoters/binders (silica) on catalyst performance.

The objective of proposed research is development of catalysts with enhanced slurry phase activity and better selectivity to fuel range products, through a more detailed understanding and systematic studies of the effects of pretreatment procedures and promoters/binders (silica) on catalyst performance.

The Nevada Operations Office (NV) is responsible for supporting the nuclear test programs of the Los Alamos and Lawrence Livermore National Laboratories. This support includes the drilling of test holes for nuclear device testing a the Nevada Test Site (NTS). The purpose of this audit was to assess the effectiveness of the Department of Energy's management of test hole inventories at the NTS. Our audit disclosed that NV accumulated a large inventory of unused test holes and approved drilling additional holes for which neither laboratory (Los Alamos nor Livermore) had identified a need. The overdrilling of test holes occurred because NV did not comply with good inventory practices that would have had NV's approving official question the need for, and the timing of, the laboratories' drilling requests. Instead, NV gave perfunctory approval to the laboratories' work orders for drilling test holes, and emphasized keeping two drill rig crews busy and satisfying the laboratories' demands for dedicated drilling personnel. Although NV did not agree that overdrilling had occurred, it has cut back its drilling activities and estimated that this will save abut $7.6 million annually. NV agreed with the recommendations in the report and has taken corrective actions.

An investigation of the effects of surface structure, dispersion, and support on the adsorption, catalytic, and electronic properties of cobalt/alumina is described, the objectives of which were to determine (1) the effects of surface structure and metal dispersion on the adsorption and catalytic properties of cobalt and (2) the effects of direct electronic interactions between metal clusters and support, on the adsorption, catalytic and electronic properties of cobalt supported on alumina. Effects of surface structure and dispersion on the adsorption, activity/selectivity, and electronic properties of Co/W single crystal surfaces and alumina-supported cobalt were investigated in a surface investigation, lab reactor studies, TPD/TPSR studies, and a Moessbauer spectroscopy study. The structure, stability, surface electronic properties, and chemisorptive properties of vapor-deposited cobalt overlayers (0-4 ML) on W(110) and W(100) were studied by Auger electron spectroscopy, low energy electron diffraction, work function changes, and temperature programmed desorption (TPD) of cobalt, hydrogen, and carbon monoxide. The CO chemisorptive properties of the two cobalt overlayers are quite different, CO adsorption being dissociative on the W(100) surface and nondissociative on the W(110) surface; comparison of the results with those for Ni/W(100) indicate that Co/W(100) dissociates CO as a result of electronic interaction with the tungsten substrate.

An investigation of the effects of surface structure, dispersion, and support on the adsorption, catalytic, and electronic properties of cobalt/alumina is described, the objectives of which were to determine (1) the effects of surface structure and metal dispersion on the adsorption and catalytic properties of cobalt and (2) the effects of direct electronic interactions between metal clusters and support, on the adsorption, catalytic and electronic properties of cobalt supported on alumina. Effects of surface structure and dispersion on the adsorption, activity/selectivity, and electronic properties of Co/W single crystal surfaces and alumina-supported cobalt were investigated in a surface investigation, lab reactor studies, TPD/TPSR studies, and a Moessbauer spectroscopy study. The structure, stability, surface electronic properties, and chemisorptive properties of vapor-deposited cobalt overlayers (0-4 ML) on W(110) and W(100) were studied by Auger electron spectroscopy, low energy electron diffraction, work function changes, and temperature programmed desorption (TPD) of cobalt, hydrogen, and carbon monoxide. The CO chemisorptive properties of the two cobalt overlayers are quite different, CO adsorption being dissociative on the W(100) surface and nondissociative on the W(110) surface; comparison of the results with those for Ni/W(100) indicate that Co/W(100) dissociates CO as a result of electronic interaction with the tungsten substrate.

The Electric Power Monthly (EPM) presents monthly summaries of electric utility statistics at the national, Census division, and State level. The purpose of this publication is to provide energy decisionmakers with accurate and timely information that may be used in forming various perspectives on electric issues that lie ahead. Data includes generation by energy source (coal, oil, gas, hydroelectric, and nuclear); generation by region; consumption of fossil fuels for power generation; sales of electric power, cost data; and unusual occurrences. A glossary is included.

Definition of petrophysical properties, such as porosity, permeability and fluid saturation, on the scale of meters, is the key to planning and control of successful Enhanced Oil Recovery techniques for domestic reservoirs. Macroscopic transport properties in reservoir rocks depend critically upon processes at the pore level involving interactions between the pore topology and the physical and chemical properties of the rock minerals and interstitial fluids. Similar interactions at the pore level determine also the macroscopic electrical and seismic properties of reservoir rocks. The objective of this research is to understand, using analysis and experiment, how fluids in pores affect the geophysical and sport properties of reservoir rocks. The goal is to develop equations-relating seismic and electrical properties of rock to the porosity, permeability and fluid saturations so as to invert geophysical images for improved reservoir management. Results from seismic measurements performed so far in this study suggest that even subtle changes in fluid contacts and the in-situ state of effective stress can be detected using geophysical imaging techniques. The experiments using Wood`s metal and wax are revealing the topology and sport properties of the pore space in clastic sedimentary rocks. A deeper understanding of these properties is considered-to be the …

This report is part of an ongoing series of quarterly publications that monitors discoveries of oil and natural gas in foreign countries and provides an analysis of the reserve additions that result. The report is prepared by the Energy Information Administration (EIA) of the US Department of Energy (DOE) under the Foreign Energy Supply Assessment Program (FESAP). It presents a summary of discoveries and reserve additions that result from recent international exploration and development activities. It is intended for use by petroleum industry analysts, various government agencies, and political leaders in the development, implementation, and evaluation of energy plans, policy, and legislation. 25 refs., 8 figs., 4 tabs.

A new numerical procedure by which field calculations in AMOS are upgraded to model rotationally symmetric cavity structures in a more accurate fashion is described. The development work is aimed at implementing a modified finite difference update scheme on an irregular grid system. Elements of an irregular grid may be chosen to better fit object boundaries, resulting in increased solution accuracy. Our approach involves the placement of field components on a non-orthogonal body fitting grid and on a dual grid which is orthogonal to the first grid. It is found that this procedure retains several important computational advantages, including the ability to exploit the implied spatial relationships between nodes. Propagating fields on an irregular grid system have been observed and comparisons between finite difference AMOS and Modified-Yee AMOS field calculations are provided.

US total energy consumption in July 1990 was 6.7 quadrillion Btu Petroleum products accounted for 42 percent of the energy consumed in July 1990, while coal accounted for 26 percent and natural gas accounted for 19 percent. Residential and commercial sector consumption was 2.3 quadrillion Btu in July 1990, up 2 percent from the July 1989 level. The sector accounted for 35 percent of July 1990 total consumption, about the same share as in July 1989. Industrial sector consumption was 2.4 quadrillion Btu in July 1990, up 2 percent from the July 1989 level. The industrial sector accounted for 36 percent of July 1990 total consumption, about the same share as in July 1989. Transportation sector consumption of energy was 1.9 quadrillion Btu in July 1990, up 1 percent from the July 1989 level. The sector consumed 29 percent of July 1990 total consumption, about the same share as in July 1989. Electric utility consumption of energy totaled 2.8 quadrillion Btu in July 1990, up 2 percent from the July 1989 level. Coal contributed 53 percent of the energy consumed by electric utilities in July 1990, while nuclear electric power contributed 21 percent; natural gas, 12 percent; hydroelectric power, 9 …

Group theoretical methods are used to obtain the form of the elastic moduli matrices and the number of independent parameters for various symmetries. Particular attention is given to symmetry groups for which 3D and 2D isotropy is found for the stress-strain tensor relation. The number of independent parameters is given by the number of times the fully symmetric representation is contained in the direct product of the irreducible representations for two symmetrical second rank tensors. The basis functions for the lower symmetry groups are found from the compatibility relations and are explicitly related to the elastic moduli. These types of symmetry arguments should be generally useful in treating the elastic properties of solids and composites.

Evidence from magnetospheric and solar flare research supports the belief that collisionless magnetic reconnection can proceed on the Alfven-wave crossing timescale. Reconnection behavior that occurs this rapidly in collisionless plasmas is not well understood because underlying mechanisms depend on the details of the ion and electron distributions in the vicinity of the emerging X-points. We use the direct implicit Particle-In-Cell (PIC) code AVANTI to study the details of these distributions as they evolve in the self-consistent E and B fields of magnetic reconnection. We first consider a simple neutral sheet model. We observe rapid movement of the current-carrying electrons away from the emerging X-point. Later in time an oscillation of the trapped magnetic flux is found, superimposed upon continued linear growth due to plasma inflow at the ion sound speed. The addition of a current-aligned and a normal B field widen the scope of our studies.

In Ion Microtomography (IMT), material densities are determined from the energy lost by ions as they pass through a specimen. For fine-scale measurements with micron-size beams, mechanical stability and precision of motion can impact the quality of the reconstruction. We describe several preprocessing procedures used to minimize imperfect specimen manipulation, including adjustment of the center of mass motion in sinograms and correction for vertical translations. In addition, the amount of noise in the reconstruction is reduced by utilizing median (as opposed to mean) ion energy loss values for density determinations. Furthermore, particular portions of the sampled image can be enhanced with minimal degradation of spatial resolution by a judicial choice of spatial filter in the reconstruction algorithm. The benefits and limitations of these preprocessing techniques are discussed.

A method for constructing a cooled optic wherein one or more cavities are milled, drilled or formed using casting or ultrasound laser machining techniques in a single crystal base and filled with porous material having high thermal conductivity at cryogenic temperatures. A non-machined strain-free single crystal can be bonded to the base to produce superior optics. During operation of the cooled optic, N{sub 2} is pumped through the porous material at a sub-cooled cryogenic inlet temperature and with sufficient system pressure to prevent the fluid bulk temperature from reaching saturation.

A method for constructing a cooled optic wherein one or more cavities are milled, drilled or formed using casting or ultrasound laser machining techniques in a single crystal base and filled with porous material having high thermal conductivity at cryogenic temperatures. A non-machined strain-free single crystal can be bonded to the base to produce superior optics. During operation of the cooled optic, N{sub 2} is pumped through the porous material at a sub-cooled cryogenic inlet temperature and with sufficient system pressure to prevent the fluid bulk temperature from reaching saturation.

A high pressure apparatus has been constructed for measuring rates of reactions in liquids under pressures ranging from 1 atm to 2000 atm. This apparatus is being used to test the effect of ligand bulk on the rate of a thermal ring closure reaction. Microphonic photoacoustic signals obtained by illuminating solid samples with synchrotron soft x-rays and with visible laser beams have been successfully correlated with a theory for photoacoustic signal enhancement by volatile liquids. The concentration dependence of the fluorescence and nonradiative quantum yields for cresyl violet dissolved in methanol has been determined. Stability constants for complexes of lithium ion with four different crown ethers dissolved in a low temperature molten salt have been measured.

At the request of the International Atomic Energy Agency (IAEA), technical assistance was provided to the Korea Atomic Energy Research Institute (KAERI) in the field of radwaste incineration and related off-gas treatment operations. The traveler provided the requested technical consolations and, in the process, obtained an understanding of the Republic of Korea's plans for the management of the the wastes from the country's nuclear power plants and research facilities. The government of the Republic of Korea has tasked KAERI to develop the facilities for treating and disposing of the wastes from the country's nuclear facilities in an environmentally responsible manner. As a step in that direction, the Radwaste Treatment Department at KAERI is developing the technology and the plans for the incineration of burnable low-level radwaste, which comprises about 35% of the wastes generated by the nuclear facilities. The incineration program at KAERI appears to be well planned. They have operated a 5-kg/h process design unit incinerator to gather the process data for scaling up the operation to a 30-kg/h demonstration plant. This demonstration plant is presently being built, with startup operations scheduled for January 1991. Data from the demonstration plant are proposed to be used for building a 120-kg/h …