X-Ray Absorption Characterization of Diesel Exhaust Particulates (open access)

X-Ray Absorption Characterization of Diesel Exhaust Particulates

We have characterized particulates from a 1993 11.1 Detroit Diesel Series 60 engine with electronic unit injectors operated using fuels with and without methylcyclopentadienyl manganese tricarbonyl (MMT) and overbased calcium sulfonate added. X-ray photoabsorption (XAS) spectroscopy was used to characterize the diesel particulates. Results reveal a mixture of primarily Mn-phosphate with some Mn-oxide, and Ca-sulfate on the surface of the filtered particulates from the diesel engine.
Date: November 18, 1999
Creator: Nelson, A J; Ferreira, J L; Reynolds, J G & Roos, J W
System: The UNT Digital Library
EVIDENCE FOR K+ YIELDS P+ VV-. (open access)

EVIDENCE FOR K+ YIELDS P+ VV-.

The first observation of the decay K{sup +} {yields} {pi}{sup +}{nu}{ovr {nu}} has been reported. The E787 experiment presented evidence for the K{sup +} {yields} {pi}{sup +}{nu}{ovr {nu}} decay, based on the observation of a single clean event from data collected during the 1995 run of the AGS (Alternating Gradient Synchrotron at Brookhaven National Laboratory). The branching ratio indicated by this observation, B(K{sup +} {yields} {pi}{sup +}{nu}{ovr {nu}}) = 4.2{sub -3.5}{sup +9.7} x 10{sup -10}, is consistent with the Standard Model expectation although the central experimental value is four times larger. The final E7878 data sample, from the 1995-98 runs, should reach a sensitivity of about five times that of the 1995 run alone. A new experiment, E949, has been given scientific approval and should start data collected in 2001. It is expected to achieve a sensitivity of more than an order of magnitude below the prediction of the Standard Model.
Date: December 18, 1998
Creator: Kettell, S.
System: The UNT Digital Library
An improved Thomas--Fermi treatment of nuclei (open access)

An improved Thomas--Fermi treatment of nuclei

I want to tell you about an improved Thomas-Fermi method for calculating shell-averaged nuclear properties, such as density distributions, binding energies, etc. A shell-averaged statistical theory is useful as the macroscopic component of microscopic-macroscopic theories of nuclei, such as the Strutinsky method, as well as in theories of nuclear matter in the bulk, relevant in astrophysical applications. In nuclear physics, as well as in atomic and molecular problems, the following question often has to be answered: you are given a potential well, say a deformed Woods-Saxon potential, into which you put N quantized fermions into the lowest N eigenstates, up to a Fermi energy'' To. You square the wave functions of the particles and add them up to get the total density [rho]([sub r][sup [yields]]) = [Sigma][sub i][sup N][vert bar][psi][sub i][vert bar][sup 2]. Is there some simple way of estimating [rho]([sub r][sup [yields]]) without going through the misery of numerically solving N partial differential Schroedinger equations for the N particles
Date: August 18, 1992
Creator: Swiatecki, W. J.
System: The UNT Digital Library
Statement of David E. Baldwin, Associate Director for Energy, Lawrence Livermore National Laboratory and John C. Crawford, Vice President, Sandia National Laboratories, California, to the Subcommittee on Research and Development of the Committee on Environment and Public Works, United States Senate, Washington, DC, March 22, 1993 (open access)

Statement of David E. Baldwin, Associate Director for Energy, Lawrence Livermore National Laboratory and John C. Crawford, Vice President, Sandia National Laboratories, California, to the Subcommittee on Research and Development of the Committee on Environment and Public Works, United States Senate, Washington, DC, March 22, 1993

Testimony was submitted to the Senate on the environmental impacts of accelerated research and development of hydrogen-based energy systems. The advantages of hydrogen in transportation systems, in fuel cells for electric vehicles and power plants, and in energy storage from off-peak electricity production were described. The largest barrier to using hydrogen in the transportation sector is the on-board storage of enough fuel to provide an adequate driving range in an urban environment. Production methods and costs were also discussed. The authors believe a coordinated demonstration program with US industry is needed to develop the best technologies for hydrogen-fueled vehicles.
Date: March 18, 1993
Creator: Baldwin, D. E. & Crawford, J. C.
System: The UNT Digital Library
Limits on high-order harmonic generation from single-atom calculations (open access)

Limits on high-order harmonic generation from single-atom calculations

In the quantum mechanical calculations of electron and photon emission from atoms in strong laser fields we have employed a single-active-electron (SAE) model. We determine the effect of the time varying electric field of the laser on each of the valence electrons separately. The active electron in each calculation moves in the time-independent mean field of the remaining, unexcited electrons and the nucleus. This approach works well for the rare gas atoms, at least partially because the neglected double or higher excitations involve states well above the ionization threshold. The photoelectron and photon emission spectra calculated using this technique agree quantitatively with observed emission rates. In this paper we will present a simple semiclassical model for high intensity ionization which reproduces the observed harmonic emission spectra obtained in this regime and which provides considerable insight into the dynamics of this process. The basic models has been used in the past to predict electron energy distributions in the tunneling regime and we will use it here for harmonics.
Date: August 18, 1993
Creator: Kulander, K. C. & Schafer, K. J.
System: The UNT Digital Library
Generation of harmonic radiation using the multi-cavity free-electron laser (open access)

Generation of harmonic radiation using the multi-cavity free-electron laser

An FEL provides a convenient method of reaching short wavelengths by resonating with an input source at the fundamental wavelength while providing bunching at a harmonic of the fundamental. Recently schemes have been proposed that use two wiggler segments, one resonant at the fundamental to pre-bunch the beam, the other lasing at the desired (third) harmonic. A similar effect, with some advantages and some disadvantages, can be achieved using the Multi-Cavity FEL (MC/FEL). The MC/FEL employs several short cavities, operating in an oscillator-like manner, to achieve high output power. In this paper we consider the use of the MC/FEL as a means of generating harmonics. We investigate the competitiveness of this option in comparison with other harmonic generation schemes, in terms of the total wiggler length needed, the saturated power achieved, and the restrictions imposed by mirror reflectivity.
Date: August 18, 1993
Creator: Krishnagopal, S. & Sessler, A. M.
System: The UNT Digital Library
A mixed time integration method for large scale acoustic fluid-structure interaction (open access)

A mixed time integration method for large scale acoustic fluid-structure interaction

The transient, coupled, interaction of sound with structures is a process in which an acoustic fluid surrounding an elastic body contributes to the effective inertia and elasticity of the body. Conversely, the presence of an elastic body in an acoustic medium influences the behavior of propagating disturbances. This paper details the application of a mixed explicit-implicit time integration algorithm to the fully coupled acoustic fluidstructure interaction problem. Based upon a dispersion analysis of the semi-discrete wave equation a second-order, explicit scheme for solving the wave equation is developed. The combination of a highly vectorized, explicit, acoustic fluid solver with an implicit structural code for linear elastodynamics has resulted in a simulation tool, PING, for acoustic fluid-structure interaction. PING`s execution rates range from 1{mu}s/Element/{delta}t for rigid scattering to 10{mu}s/Element/{delta}t for fully coupled problems. Several examples of PING`s application to 3-D problems serve in part to validate the code, and also to demonstrate the capability to treat complex geometry, acoustic fluid-structure problems which require high resolution meshes.
Date: July 18, 1994
Creator: Christon, M. A.; Wineman, S. J.; Goudreau, G. L. & Foch, J. D.
System: The UNT Digital Library
Environmental restoration and decontamination & decommissioning safety documentation. Revision 2 (open access)

Environmental restoration and decontamination & decommissioning safety documentation. Revision 2

This document presents recommendations of a working group designated by the Environmental Restoration and Remediation (ER) and Decontamination and Decommissioning (D&D) subcommittees of the Westinghouse M&O (Management and Operation) Nuclear Facility Safety Committee. A commonalty of approach to safety documentation specific to ER and D&D activities was developed and is summarized below. Allowance for interpretative tolerance and documentation flexibility appropriate to the activity, graded for hazard category, duration, and complexity, was a primary consideration in development of this guidance.
Date: May 18, 1993
Creator: Hansen, J. L.; Frauenholz, L. H. & Kerr, N. R.
System: The UNT Digital Library
The superconducting magnet system for the Tokamak Physics Experiment (open access)

The superconducting magnet system for the Tokamak Physics Experiment

The superconducting magnet system for the Tokamak Physics experiment (TPX) will be the first all superconducting magnet system for a Tokamak, where the poloidal field coils, in addition to the toroidal field coils are superconducting. The magnet system is designed to operate in a steady state mode, and to initiate the plasma discharge ohmically. The toroidal field system provides a peak field of 4.0 Tesla on the plasma axis at a plasma major radius of 2.25 m. The peak field on the niobium 3-tin, cable-in-conduit (CIC) conductor is 8.4 Tesla for the 16 toroidal field coils. The toroidal field coils must absorb approximately 5 kW due to nuclear heating, eddy currents, and other sources. The poloidal field system provides a total of 18 volt seconds to initiate the plasma and drive a plasma current up to 2 MA. The poloidal field system consists of 14 individual coils which are arranged symmetrically above and below the horizontal mid plane. Four pairs of coils make up the central solenoid, and three paris of poloidal ring coils complete the system. The poloidal field coils all use a cable-in-conduit conductor, using either niobium 3-tin (NB{sub 3}Sn) or niobium titanium (NbTi) superconducting strands depending on …
Date: June 18, 1994
Creator: Lang, D. D.; Bulmer, R. J. & Chaplin, M. R.
System: The UNT Digital Library
Incorporating long-term climate change in performance assessment for the Waste Isolation Pilot Plant (open access)

Incorporating long-term climate change in performance assessment for the Waste Isolation Pilot Plant

The United States Department of Energy (DOE) is developing the Waste Isolation Pilot Plant (WIPP) in southeastern New Mexico for the disposal of transuranic wastes generated by defense programs. Applicable regulations (40 CFR 191) require the DOE to evaluate disposal-system performance for 10,000 yr. Climatic changes may affect performance by altering groundwater flow. Paleoclimatic data from southeastern New Mexico and the surrounding area indicate that the wettest and coolest Quaternary climate at the site can be represented by that at the last glacial maximum, when mean annual precipitation was approximately twice that of the present. The hottest and driest climates have been similar to that of the present. The regularity of global glacial cycles during the late Pleistocene confirms that the climate of the last glacial maximum is suitable for use as a cooler and wetter bound for variability during the next 10,000 yr. Climate variability is incorporated into groundwater-flow modeling for WIPP PA by causing hydraulic head in a portion of the model-domain boundary to rise to the ground surface with hypothetical increases in precipitation during the next 10,000 yr. Variability in modeled disposal-system performance introduced by allowing head values to vary over this range is insignificant compared to …
Date: September 18, 1993
Creator: Swift, P. N.; Baker, B. L.; Economy, K.; Garner, J. W.; Helton, J. C. & Rudeen, D. K.
System: The UNT Digital Library
Parametric variations of ion transport in TFTR (open access)

Parametric variations of ion transport in TFTR

This paper is divided into three roughly independent sections. The first is a historical review of the twenty year history of experimental ion heat transport measurements from many tokamaks. The second is a study of ion heat transport in Ohmic TFTR plasmas which shows that {chi}i {approximately} {chi}e {approx} 15{chi}i{sup neo}. Thus, ion heat transport is demonstrated to be strongly anomalous even the absence of auxiliary heating. The third section describes the variation of {chi}i with local ion temperature in TFTR during auxiliary heating, with emphasis on characterizing the differecens between transport in the L-mode and supershot regimes. The results are consistent with the conjecture that improved ion energy confinement in supershot plasmas is caused by a high ratio of T{sub 1}/T{sub e}.
Date: March 18, 1993
Creator: Scott, S. D.; Barnes, C. W. & Ernst, D.
System: The UNT Digital Library
Technology development for recirculating heavy-ion accelerators (open access)

Technology development for recirculating heavy-ion accelerators

The {open_quotes}recirculator,{close_quotes} a recirculating heavy-ion accelerator has been identified as a promising approach for an inertial fusion driver. System studies have been conducted to evaluate the recirculator on the basis of feasibility and cost. The recirculator has been shown to have significant cost advantages over other potential driver schemes, but some of the performance requirements exceed the capabilities of present technology. The system studies identified the high leverage areas where advances in technology will significantly impact the cost and performance of a recirculator. One of the high leverage areas is the modulator system which generates the acceleration potentials in the induction cells. The modulator system must be capable of generating the acceleration potentials at peak repetition rates in excess of 100 kHz with variable pulse widths. LLNL is developing a modulator technology capable of driving induction cells using the latest in solid state MOSFET technology. A small scale modulator has been built and tested to prove the concept and the next version is presently being designed. The objective is to demonstrate a modulator operating at 5 kV, 1 kA, with 0.2--1 {mu}s pulse widths while driving an induction cell at >100 kHz within the next year. This paper describes the …
Date: May 18, 1993
Creator: Newton, M. A. & Kirbie, H. C.
System: The UNT Digital Library
A tau-charm-factory at Argonne (open access)

A tau-charm-factory at Argonne

In this paper we explore the possibility of building a tau-charm-factory at the Argonne National Laboratory. A tau-charm-factory is an e{sup +}e{sup {minus}} collider with a center-of-mass energy between 3.0 GeV and 5.0 GeV and a luminosity of at least 1 {times} 10{sup 33}cm{sup {minus}2}s{sup {minus}1}. Once operational, the facility will produce large samples of {tau} pairs, charm mesons, and charmonium with either negligible or well understood backgrounds. This will lead to high precision measurements in the second generation quark and the third generation lepton sectors that cannot be done at other facilities. Basic physical properties and processes, such as the tau neutrino mass, rare tau decays, charm decay constants, rare charm meson decays, neutral D{sup 0} -- meson mixing, and many more will be studied with unique precision. An initial design of the collider including the injector system is described. The design shows that a luminosity of at least 1 {times} 10{sup 33}cm{sup {minus}2}s{sup {minus}1} can be achieved over the entire center-of-mass energy range of the factory.
Date: July 18, 1994
Creator: Norem, J. & Repond, J.
System: The UNT Digital Library
Lithological and rheological constraints on fault rupture scenarios for ground motion hazard prediction (open access)

Lithological and rheological constraints on fault rupture scenarios for ground motion hazard prediction

This paper tests an approach to predict the range of ground motion hazard at specific sites generated by earthquakes on specific faults. The approach is based upon structural, lithological and rheological descriptions of the fault zones, development of fault rupture scenarios, and computation of synthetic seismograms using empirical Green`s functions. Faults are placed within a regional geomechanical model. The approach is based upon three hypothesis: (1) An exact solution of the representation relation that utilizes empirical Green`s functions enables very accurate computation of ground motions generated by a given rupture; (2) a general description of the rupture is sufficient; and (3) the structural, lithological and Theological characteristics of a fault can be used to constrain, in advance, possible future rupture histories. Ground motion hazard here refers to three-component, full wave train descriptions of displacement, velocity, and acceleration over the frequency band 0.01 to 25 Hz. Corollaries to these hypotheses are that the range of possible fault rupture histories is narrow enough to functionally constrain the range of strong ground motion predictions, and that a discreet set of rupture histories is sufficient to span the infinite combinations possible from a given range of rupture parameters.
Date: April 18, 1994
Creator: Hutchings, L. & Foxall, W.
System: The UNT Digital Library
Fundamental theory of light for applications: Notes for five informal lectures (open access)

Fundamental theory of light for applications: Notes for five informal lectures

These notes give an overview of some aspects of the quantum theory of light and its interaction with matter. A description is given of basic emission and absorption processes, as well as the theory of photodetection and optical coherence. Basic research in this area is increasingly relevant to areas of technological importance, including microlaser devices and the noise characteristics of semiconductor lasers.
Date: June 18, 1993
Creator: Milonni, P. W.
System: The UNT Digital Library
Preliminary studies to determine the shelf life of HEPA filters (open access)

Preliminary studies to determine the shelf life of HEPA filters

We have completed a preliminary study using filter media tests and filter qualification tests to investigate the effect of shelf-life on HEPA filter performance. Our media studies showed that the tensile strength decreased with age, but the data were not sufficient to establish a shelf-life. Thermogravimetric analyses demonstrated that one manufacturer had media with low tensile strength due to insufficient binder. The filter qualification tests (heated air and overpressure) conducted on different aged filters showed that filter age is not the primary factor affecting filter performance; materials and the construction design have a greater effect. An unexpected finding of our study was that sub-standard HEPA filters have been installed in DOE facilities despite existing regulations and filter qualification tests. We found that the filter with low tensile strength failed the overpressure test. The same filter had passed the heated air test, but left the filter so structurally weak, it was prone to blowout. We recommend that DOE initiate a filter qualification program to prevent this occurrence.
Date: July 18, 1994
Creator: Gilbert, H.; Fretthold, J. K.; Rainer, F.; Bergman, W. & Beason, D.
System: The UNT Digital Library
Large-scale testing of structural clay tile infilled frames (open access)

Large-scale testing of structural clay tile infilled frames

A summary of large-scale cyclic static tests of structural clay tile infilled frames is given. In-plane racking tests examined the effects of varying frame stiffness, varying infill size, infill offset from frame centerline, and single and double wythe infill construction. Out-of-plane tests examined infilled frame response to inertial loadings and inter-story drift loadings. Sequential in-plane and out-of-plane loadings were performed to determine the effects of orthogonal damage and degradation on both strength and stiffness. A combined out-of-plane inertial and in-plane racking test was conducted to investigate the interaction of multi-directional loading. To determine constitutive properties of the infills, prism compression, mortar compression and various unit tile tests were performed.
Date: March 18, 1993
Creator: Flanagan, R. D. & Bennett, R. M.
System: The UNT Digital Library
Workshop on tritium safety and environmental effects, October 15--17, 1990, Aiken, South Carolina: Session summaries (open access)

Workshop on tritium safety and environmental effects, October 15--17, 1990, Aiken, South Carolina: Session summaries

A meeting was held on October 15, 16, 17, 1990 to discuss the state of tritium safety and environmental effects. The meeting was organized with the help of the International Energy Agency planning committee consisting of K. Steinmetz, Y. Seki, G. Nardella, and G. Vivian. Representative of tritium production facilities and heavy water reactor power production were also involved. The meeting was organized to address seven topics in tritium safety that were thought to require further work. The topics were: (1) materials science, (2) environmental models, (3) environmental model validation, (4) tritiated organic compounds, (5) human dosimetry, (6) tritium sampling and measurement, and (7) long-term environmental databases.
Date: April 18, 1991
Creator: Murphy, C. E. Jr.
System: The UNT Digital Library
Foam is a decon waste minimization tool (open access)

Foam is a decon waste minimization tool

The use of foam in decontamination operations offers significant reductions in waste generation. Initial use has confirmed its effectiveness. Issues being resolved at Savannah River Site (SRS) include compatibility of foam generating solutions with decontamination solutions, waste disposal, and operational safety.
Date: April 18, 1991
Creator: Peterson, K. D.; McGlynn, J. F. & Rankin, W. N.
System: The UNT Digital Library
Stapp`S Quantum Dualism: The James/Heisenberg Model of Consciousness (open access)

Stapp`S Quantum Dualism: The James/Heisenberg Model of Consciousness

Henry Stapp attempts to resolve the Cartesian dilemma by introducing what the author would characterize as an ontological dualism between mind and matter. His model for mind comes from William James` description of conscious events and for matter from Werner Heisenberg`s ontological model for quantum events (wave function collapse). His demonstration of the isomorphism between the two types of events is successful, but in the author`s opinion fails to establish a monistic, scientific theory. The author traces Stapp`s failure to his adamant rejection of arbitrariness, or `randomness`. This makes it impossible for him (or for Bohr and Pauli before him) to understand the power of Darwin`s explanation of biology, let along the triumphs of modern `neo-Darwinism`. The author notes that the point at issue is a modern version of the unresolved opposition between Leucippus and Democritus on one side and Epicurus on the other. Stapp`s views are contrasted with recent discussions of consciousness by two eminent biologists: Crick and Edelman. They locate the problem firmly in the context of natural selection on the surface of the earth. Their approaches provide a sound basis for further scientific work. The author briefly examines the connection between this scientific (rather than ontological) framework …
Date: February 18, 1994
Creator: Noyes, H. P.
System: The UNT Digital Library
The role of heating and current drive in ITER (open access)

The role of heating and current drive in ITER

This report discusses and summarize the role of heating and non-inductive current drive in ITER as: (1) ITER must have heating power sufficient for ignition. (2) The heating system must be capable of current drive. (3) Steady-state operation is an ``ultimate goal.`` It is recognized that additional heating and current drive power (beyond what is initially installed on ITER) may be required. (4) The ``Ultimate goal of steady-state operation`` means steady-state with Q{sub CD} {ge} 5. Unlike the ``Terms of Reference`` for the ITER CDA, the ``ITER Technical Objectives and Approaches`` for the EDA sets no goal for the neutron wall load during steady-state operation. (5) In addition to bulk current drive, the ITER heating and current drive system should be used for current profile control and for burn control.
Date: October 18, 1993
Creator: Nevins, W. M. & Haney, S.
System: The UNT Digital Library
Experimental evidence for lattice effects in high temperature superconductors (open access)

Experimental evidence for lattice effects in high temperature superconductors

We present an overview of the experimental evidence for a role of the lattice in the mechanism of high temperature superconductivity. It appears unlikely that a solely conventional electron-phonon interaction produces the pairing. However, there is ample evidence of strong electron and spin to lattice coupling and observations of a response of the lattice to the electronic state. We draw attention to the importance of the local structure in discussions of lattice effects in high-{Tc} superconductivity.
Date: January 18, 1994
Creator: Billinge, S. J. L.; Kwei, G. H. & Thompson, J. D.
System: The UNT Digital Library
Development of subcontractor indirect cost and other direct cost at the DOE Fernald Site (open access)

Development of subcontractor indirect cost and other direct cost at the DOE Fernald Site

The Fernald Environmental Restoration Management Corporation (FERMCO) took great strides in the development of cost estimates at Fernald. There have been many opportunities to improve on how the policies and procedures pertaining to cost estimates were to be implemented. As FERMCO took over the existing Fernald facility, the Project Controls Division began to format the estimating procedures and tools to do business at Fernald. The Estimating Department looked at the problems that pre-existed at the site. One of the key problems that FERMCO encountered was how to summarized the direct and indirect accounts of each subcontracted estimate. Direct costs were broken down by prime and sub-prime accounts. This presented a level of detail that had not been experienced at the site before; it also created many issues concerning accounts and definitions to be applied to ``all other accounts associated with a project.`` Existing subcontract indirect cost accounts were reviewed from existing historical estimates. It was found that some were very detailed and some were not. The Estimating Department was given the task of standardizing the accounts and percentages for each of the subcontractor indirect costs. Then, as the project progressed, the percentages could be revised with actual estimates, subcontract comparisons, …
Date: November 18, 1994
Creator: Cossman, R. L.
System: The UNT Digital Library
Coupling correction using closed orbit measurements (open access)

Coupling correction using closed orbit measurements

The authors describe a coupling correction scheme they have developed and used to successfully reduce the vertical emittance of the NSLS X-Ray ring by a factor of 6 to below 2 A. This gives a vertical to horizontal emittance ratio of less than 0.2%. They find the strengths of 17 skew quadrupoles to simultaneously minimize the vertical dispersion and the coupling. As a measure of coupling they utilize the shift in vertical closed orbit resulting from a change in strength of a horizontal steering magnet. Experimental measurements confirm the reduced emittance.
Date: February 18, 1994
Creator: Safranek, J. & Krinsky, S.
System: The UNT Digital Library