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The flash pyrolysis and methanolysis of biomass (wood) for production of ethylene, benzene and methanol (open access)

The flash pyrolysis and methanolysis of biomass (wood) for production of ethylene, benzene and methanol

The process chemistry of the flash pyrolysis of biomass (wood) with the reactive gases, H{sub 2} and CH{sub 4} and with the non-reactive gases He and N{sub 2} is being determined in a 1 in. downflow tubular reactor at pressures from 20 to 1000 psi and temperatures from 600 to 1000{degrees}C. With hydrogen, flash hydropyrolysis leads to high yields of methane and CO which can be used for SNG and methanol fuel production. With methane, flash methanolysis leads to high yields of ethylene, benzene and CO which can be used for the production of valuable chemical feedstocks and methanol transportation fuel. At reactor conditions of 50 psi and 1000{degrees}C and approximately 1 sec residence time, the yields based on pine wood carbon conversion are up to 25% for ethylene, 25% for benzene, and 45% for CO, indicating that over 90% of the carbon in pine is converted to valuable products. Pine wood produces higher yields of hydrocarbon products than Douglas fir wood; the yield of ethylene is 2.3 times higher with methane than with helium or nitrogen, and for pine, the ratio is 7.5 times higher. The mechanism appears to be a free radical reaction between CH{sub 4} and the …
Date: February 1, 1990
Creator: Steinberg, M.; Fallon, P. T. & Sundaram, M. S.
System: The UNT Digital Library
A continuous plasma final focus (open access)

A continuous plasma final focus

Scaling laws are set down for a plasma cell used for transport, focusing and current neutralization of fine, intense, relativistic electron beams. It is found that there exists a minimum beam spot size, {sigma}{sub min} {approximately} {epsilon}{sub n}(I{sub A}/{gamma}I){sup 1/2}, in such a focusing system. Propagation issues, including channel formation, synchrotron radiation, beam ionization and instabilities, are discussed. Three numerical examples are considered. 38 refs., 2 figs., 1 tab.
Date: February 1, 1990
Creator: Whittum, D.H.
System: The UNT Digital Library
The surface energy and the compressibility (open access)

The surface energy and the compressibility

This paper discusses the relationship between surface energy and compressibility as they relate to the nucleus. 5 refs., 4 figs. (LSP)
Date: February 1, 1990
Creator: Myers, W.D.
System: The UNT Digital Library
The magnetic design and field measurement of Fermilab collider detectors: CDF (the Collider Detector at Fermilab) and D0 (open access)

The magnetic design and field measurement of Fermilab collider detectors: CDF (the Collider Detector at Fermilab) and D0

General magnetic characteristics of the CDF and D0 hadron collider detectors at Fermilab are described. The method and equipment for the field measurement for both detectors are described, and their field measurement data are presented. The magnetic field distribution inside the CDF solenoid magnet was measured extensively only at the boundaries, and the field values inside the volume were reconstructed. The effects due to the joints and the return conductor were measured and are discussed. The flux distribution inside the yokes and the fringing field of the D0 toroids were calculated and compared with measured data. A proposal to generate dipole magnetic field inside the D0 toroidal magnet is discussed. 9 refs., 6 figs.
Date: February 1, 1990
Creator: Yamada, R.
System: The UNT Digital Library
A high temperature, plasma-assisted chemical vapor deposition system (open access)

A high temperature, plasma-assisted chemical vapor deposition system

We have designed and built a high-temperature, plasma-assisted, chemical vapor deposition system to deposit multilayer optical coatings of SiO{sub 2} and doped-SiO{sub 2} flat substrates. The coater concept and design is an outgrowth of our recent work with Schott Glasswerke demonstrating the use of plasma assisted CVD to prepare very high damage threshold optical coatings. The coater is designed to deposit up to several thousand alternating quarterwave layers of SiO{sub 2} and doped SiO{sub 2} substrate at deposition rates up to several microns per minute. The substrate is resistively heated to about 1000{degree}C during the deposition phase of the process. The plasma is driven by a 13.56 MHz RF unit capable of producing power densities of up to 140 W cm{sup {minus}3} in the reaction zone. The coater is designed to be adaptable to microwave generated plasmas, as well as RF. Reactant gas flow rates of up to 10 slm can be achieved at a 10 tar operating pressure. Reactants consist of O{sub 2}, SiCl{sub 4} and a volatile halogenated dopant. These gases react in the plasma volume producing SiO{sub 2} with dopant concentrations of up to a few percent. A variable dopant concentration is used to produce index differences …
Date: February 1, 1990
Creator: Brusasco, R. M.; Britten, J. A.; Thorsness, C. B.; Scrivener, M. S.; Unites, W. G.; Campbell, J. H. (Lawrence Livermore National Lab., CA (USA)) et al.
System: The UNT Digital Library
Fast pulsars, strange stars (open access)

Fast pulsars, strange stars

The initial motivation for this work was the reported discovery in January 1989 of a 1/2 millisecond pulsar in the remnant of the spectacular supernova, 1987A. The status of this discovery has come into grave doubt as of data taken by the same group in February, 1990. At this time we must consider that the millisecond signal does not belong to the pulsar. The existence of a neutron star in remnant of the supernova is suspected because of recent observations on the light curve of the remnant, and of course by the neutrino burst that announced the supernova. However its frequency is unknown. I can make a strong case that a pulsar rotation period of about 1 ms divides those that can be understood quite comfortably as neutron stars, and those that cannot. What we will soon learn is whether there is an invisible boundary below which pulsar periods do not fall, in which case, all are presumable neutron stars, or whether there exist sub- millisecond pulsars, which almost certainly cannot be neutron stars. Their most plausible structure is that of a self-bound star, a strange-quark-matter star. The existence of such stars would imply that the ground state of the …
Date: February 1, 1990
Creator: Glendenning, N.K.
System: The UNT Digital Library
Fast Flux Test Facility core restraint system performance (open access)

Fast Flux Test Facility core restraint system performance

Characterizing Fast Flux Test Facility (FFTF) core restraint system performance has been ongoing since the first operating cycle. Characterization consists of prerun analysis for each core load, in-reactor and postirradiation measurements of subassembly withdrawal loads and deformations, and using measurement data to fine tune predictive models. Monitoring FFTF operations and performing trend analysis has made it possible to gain insight into core restraint system performance and head off refueling difficulties while maximizing component lifetimes. Additionally, valuable information for improved designs and operating methods has been obtained. Focus is on past operating experience, emphasizing performance improvements and avoidance of potential problems. 4 refs., 12 figs., 2 tabs.
Date: February 1, 1990
Creator: Hecht, S. L. & Trenchard, R. G.
System: The UNT Digital Library
Shell model calculations for exotic nuclei (open access)

Shell model calculations for exotic nuclei

In this paper we review the progress of the shell-model approach to understanding the properties of light exotic nuclei (A < 40). By shell-model'' we mean the consistent and large-scale application of the classic methods discussed, for example, in the book of de-Shalit and Talmi. Modern calculations incorporate as many of the important configurations as possible and make use of realistic effective interactions for the valence nucleons. Properties such as the nuclear densities depend on the mean-field potential, which is usually separately from the valence interaction. We will discuss results for radii which are based on a standard Hartree-Fock approach with Skyrme-type interactions.
Date: February 1, 1990
Creator: Brown, B.A. (Michigan State Univ., East Lansing, MI (USA)); Warburton, E.K. (Brookhaven National Lab., Upton, NY (USA)) & Wildenthal, B.H. (New Mexico Univ., Albuquerque, NM (USA). Dept. of Physics and Astronomy)
System: The UNT Digital Library
Application of Soil Venting at a Large Scale: A Data and Modeling Analysis (open access)

Application of Soil Venting at a Large Scale: A Data and Modeling Analysis

Soil venting will be applied at a demonstration scale to a site at the Idaho National Engineering Laboratory which is contaminated with carbon tetrachloride and other organic vapors. The application of soil venting at the site is unique in several aspects including scale, geology, and data collection. The containmented portion of the site has a surface area of over 47,000 square meters (12 acres) and the depth to the water table is approximately 180 meters. Migration of contaminants through the entire depth of the vadose zone is evidenced by measured levels of chlorinated solvents in the underlying aquifer. The geology of the site consists of a series of layered basalt flows interspersed with sedimentary interbeds. The depth of the vadose zone, the nature of fractured basalt flows, and the degree of contamination all tend to make drilling difficult and expensive. Because of the scale of the site, extent of contamination, and expense of drilling, a computer model has been developed to simulate the migration of the chlorinated solvents during plume growth and cleanup. The demonstration soil venting operation has been designed to collect pressure drop and plume migration data to assist with calibration of the transport model. The model will …
Date: February 27, 1990
Creator: Walton, J. C.; Baca, R. G.; Sisson, J. B. & Wood, T. R.
System: The UNT Digital Library
Fixed Target Electroweak and Hard Scattering Physics (open access)

Fixed Target Electroweak and Hard Scattering Physics

The possibilities for future physics and experiments involving weak and electromagnetic interactions, neutrino oscillations, general hard scattering and experiments involving nuclear targets were explored. The studies were limited to the physics accessible using fixed target experimentation. While some of the avenues explored turn out to be relatively unrewarding in the light of competition elsewhere in the world, there are a number of positive conclusions reached about experimentation in the energy range available to the Main Injector and Tevatron. Some of the experiments would benefit from the increased intensity available from the Tevatron utilizing the Main Injector, while some require this increase. Finally, some of the experiments would use the Main Injector low energy, high intensity extracted beams directly. A program of electroweak and hard scattering experiments at fixed target energies retains the potential for important contributions to physics. The key to major parts of this program would appear to be the existence of the Main Injector. 115 refs, 17 figs.
Date: February 1, 1990
Creator: Brock, R.; Brown, C. N.; Montgomery, H. E. & Corcoran, M. D.
System: The UNT Digital Library
The need for the next linear collider (open access)

The need for the next linear collider

The need for the next generation electron-positron collider is discussed within the context of the Standard Model and the physics that must lie beyond it.
Date: February 1, 1990
Creator: Gilman, Frederick J.
System: The UNT Digital Library
Global Warming: A Northwest Perspective (open access)

Global Warming: A Northwest Perspective

The Northwest Power Planning Council convened a symposium in Olympia, Washington, on the subject of global climate change ( the greenhouse effect'') and its potential for affecting the Pacific Northwest. The symposium was organized in response to a need by the Power Council to understand global climate change and its potential impacts on resource planning and fish and wildlife planning for the region, as well as a need to understand national policy developing toward climate change and the Pacific Northwest's role in it. 40 figs., 15 tabs.
Date: February 1990
Creator: Scott, M. J. & Counts, C. A.
System: The UNT Digital Library
Search for the top quark in electron-muon events with CDF (open access)

Search for the top quark in electron-muon events with CDF

The CDF detector has collected data for an integrated luminosity of 4.4 pb{sup {minus}1} during the 1988--89 Tevatron Collider run. This sample has been used to search for the top quark. We report here the results of the analysis of the electron-muon topology. We find that a top mass in the 28 to 72 GeV is excluded at the 95% confidence level. The same limits apply to a possible fourth generation, charge {minus}1/3, b{prime} quark decaying via the charged current. 21 refs., 14 figs.
Date: February 1, 1990
Creator: Barbaro-Galtieri, A.
System: The UNT Digital Library
The EGS4 Code System: Solution of gamma-ray and electron transport problems (open access)

The EGS4 Code System: Solution of gamma-ray and electron transport problems

In this paper we present an overview of the EGS4 Code System -- a general purpose package for the Monte Carlo simulation of the transport of electrons and photons. During the last 10-15 years EGS has been widely used to design accelerators and detectors for high-energy physics. More recently the code has been found to be of tremendous use in medical radiation physics and dosimetry. The problem-solving capabilities of EGS4 will be demonstrated by means of a variety of practical examples. To facilitate this review, we will take advantage of a new add-on package, called SHOWGRAF, to display particle trajectories in complicated geometries. These are shown as 2-D laser pictures in the written paper and as photographic slides of a 3-D high-resolution color monitor during the oral presentation. 11 refs., 15 figs.
Date: February 9, 1990
Creator: Nelson, W. R. & Namito, Yoshihito.
System: The UNT Digital Library
Microseismic monitoring of the Chaveroo oil field, New Mexico (open access)

Microseismic monitoring of the Chaveroo oil field, New Mexico

Microseismicity was monitored in the Chaveroo oil field in southeastern New Mexico during, and for 5 weeks following, a pressurized stimulation of a well being prepared as an injector for a water flood operation. Three-thousand barrels of water were injected into the reservoir over a 5.5-hour period. Little seismicity was detected during the stimulation. Intermittent monitoring over a 5-week period following the injection indicated detectable seismicity occurring with activity levels varying in time. The most active period recorded occurred just after production resumed in the immediate area of the monitor well. Mapping the microearthquakes using the hodogram technique indicates the events occur along linear trends which corroborate known structural trends of the field. Seismicity trends were defined both parallel and perpendicular to the regionally defined maximum horizontal stress direction. Seventy-three good quality events were recorded, in a cumulative 24 hour period, from which structures were mapped up to 3000 ft from the monitor well. 13 refs., 9 figs.
Date: February 6, 1990
Creator: Rutledge, J. T. & Albright, J. N.
System: The UNT Digital Library
Status of the Tau-Charm Facility and highlights of its physics program (open access)

Status of the Tau-Charm Facility and highlights of its physics program

In this paper I will first discuss the history and current status of the Tau-Charm Facility. I will then focus on the unique aspects of the heavy meson and tau physics program of such a facility, which motivates its construction and operation in the mid-1090's.
Date: February 1, 1990
Creator: Schindler, R. H.
System: The UNT Digital Library
Direct imaging of the atomic structure and chemistry of defects and interfaces by Z-contrast STEM (scanning transmission electron microscopy) (open access)

Direct imaging of the atomic structure and chemistry of defects and interfaces by Z-contrast STEM (scanning transmission electron microscopy)

Z-contrast scanning transmission electron microscopy (STEM) is a fundamentally new approach to high-resolution imaging which provides unambiguous, compositionally sensitive images on the atomic scale. Such images are intuitively interpretable, even in thick regions of the sample, tremendously simplifying determination of the structure and chemistry of defects and interfaces. To illustrate this, examples are presented of commonly observed planar defects in laser-ablated thin films of YBa{sub 2}Cu{sub 3}O{sub 7-x}. Film/substrate interfaces are shown to be chemically diffuse on the atomic scale and steps or undulations in the substrate need not result in defects in the film. Low-angle grain boundaries are found to be chemically clean, the drastic reductions in critical currents with tilt angle being due to the array of intrinsic structural defects comprising the boundary. 20 refs., 10 figs.
Date: February 1, 1990
Creator: Pennycook, S. J.; Chisholm, M. F.; Jesson, D. E.; Norton, D. P.; McCamy, J. W. & Lowndes, D. H.
System: The UNT Digital Library
PC-based PCM telemetry data reduction system software (open access)

PC-based PCM telemetry data reduction system software

The Solar Energy Research Institute&#x27;s (SERI) Wind Research Program is using pulse code modulation (PCM) telemetry systems to study horizontal-axis wind turbines. SERI has developed a low-cost PC-based PCM data-acquisition system to facilitate quick PCM data analysis in the field. The SERI PC-PCM system consists of AT-compatible hardware boards for decoding and combining PCM data streams and DOS software for control and management of data acquisition. Up to four boards can be installed in a single PC, providing the capability to combine data from four PCM streams direct to disk or memory. This paper describes the SERI Quick-Look Data Management Program, which is a comprehensive software package used to organize, acquire, process, and display information from PCM data streams. The software was designed for use in conjunction with SERI&#x27;s PC-PCM hardware described in a related paper. Features of the Quick-Look program are highlighted, including those which make it useful in an experiment test environment to quickly examine and verify incoming data. Also discussed are problems and techniques associated with PC-based PCM data acquisition, processing, and real-time display. 7 refs., 4 figs., 2 tabs.
Date: February 1, 1990
Creator: Simms, D. A.
System: The UNT Digital Library
A finite Zitterbewegung model for relativistic quantum mechanics (open access)

A finite Zitterbewegung model for relativistic quantum mechanics

Starting from steps of length h/mc and time intervals h/mc{sup 2}, which imply a quasi-local Zitterbewegung with velocity steps {plus minus}c, we employ discrimination between bit-strings of finite length to construct a necessary 3+1 dimensional event-space for relativistic quantum mechanics. By using the combinatorial hierarchy to label the strings, we provide a successful start on constructing the coupling constants and mass ratios implied by the scheme. Agreement with experiments is surprisingly accurate. 22 refs., 1 fig.
Date: February 19, 1990
Creator: Noyes, H. P.
System: The UNT Digital Library
MORT (Management Oversight and Risk Tree) based risk management (open access)

MORT (Management Oversight and Risk Tree) based risk management

Risk Management is the optimization of safety programs. This requires a formal systems approach to hazards identification, risk quantification, and resource allocation/risk acceptance as opposed to case-by-case decisions. The Management Oversight and Risk Tree (MORT) has gained wide acceptance as a comprehensive formal systems approach covering all aspects of risk management. It (MORT) is a comprehensive analytical procedure that provides a disciplined method for determining the causes and contributing factors of major accidents. Alternatively, it serves as a tool to evaluate the quality of an existing safety system. While similar in many respects to fault tree analysis, MORT is more generalized and presents over 1500 specific elements of an ideal ''universal'' management program for optimizing occupational safety.
Date: February 1, 1990
Creator: Briscoe, G. J.
System: The UNT Digital Library
High luminosity muon scattering at FNAL (open access)

High luminosity muon scattering at FNAL

The charge of this group was to evaluate the physics that can be done with a high luminosity {mu} scattering experiment at FNAL using the upgraded Tevatron muon beam, and consider the apparatus required. In this report, the physics that can be accomplished with a high luminosity {mu} scattering experiment is evaluated. The CERN and FNAL {mu} beams are compared in the context of such an experiment. The expected muon flux with the upgraded machine is estimated. Two possible detectors are compared: the air-core toroid experiment proposed by Guyot et al., and an upgraded version of the E665 double-diode apparatus now in place at FNAL. The relative costs of the detectors are considered. A list of detailed questions that need to be answered regarding the double-diode experiment has be compiled. 2 refs., 10 figs., 2 tabs.
Date: February 1, 1990
Creator: Bazizi, K. (California Univ., Riverside, CA (USA)); Conrad, J.; Fang, G. (Harvard Univ., Cambridge, MA (USA)); Erdmann, M. (Freiburg Univ. (Germany, F. R.)); Geesaman, D.; Jackson, H. (Argonne National Lab., IL (USA)) et al.
System: The UNT Digital Library
Physics Program in Hall A at CEBAF (open access)

Physics Program in Hall A at CEBAF

We present here the physics program planned for Hall A at CEBAF. It encompasses exclusive as well as inclusive electromagnetic measurements requiring both high precision and accuracy.The program includes measurements of the elementary form factors of the nucleon, systematic studies of the few nucleon systems (d, 3,4He), high momentum structure of nuclei, their structure at high Q^2 to look for hadronization and quark effects, spin response of nuclei via (vector-e, e'vector-p) reactions and the study of nuclear pion fields.
Date: February 1, 1990
Creator: Saha, Arunava
System: The UNT Digital Library
Role of underground testing to determine suitability of Yucca Mountain as a potential repository site (open access)

Role of underground testing to determine suitability of Yucca Mountain as a potential repository site

A brief description of the Exploratory Shaft based site characterization testing program for the Yucca Mountain Project of the permanent disposal of high level radioactive waste is briefly described in this paper. Details of the testing program are presented in the DOE-issued Site Characterization Plan. Overview of the current planning process and status of various activities is briefly described. This study will reevaluate the mining method, ESF location and any changes in the ESF testing program. 2 refs., 2 figs., 1 tab.
Date: February 1, 1990
Creator: Kalia, H.N.
System: The UNT Digital Library
Prototype testing for the Yucca Mountain Project (open access)

Prototype testing for the Yucca Mountain Project

The US Department of Energy, through its Yucca Mountain Project Office, has been conducting prototype activities in welded and non-welded tuff. These activities are in preparation for characterization of the Yucca Mountain area, which is under consideration as a site for a geologic repository in which high-level nuclear waste could be safely stored. Investigators from organizations that will conduct the site investigation have been afforded opportunity, through the prototype program, to test, evaluate, and develop instruments, equipment, and methods. The Exploratory Shaft Facility will be used to collect significant amounts of underground site characterization data. The prototype tests are conducted under similar conditions. 3 refs., 4 figs.
Date: February 1990
Creator: Kalia, H. N.; Oliver, R. D. & Girdley, W. A.
System: The UNT Digital Library