Thyratron characteristics under high di/dt and high-repetition-rate operation (open access)

Thyratron characteristics under high di/dt and high-repetition-rate operation

Power conditioning systems for high peak and average power, high repetition rate discharge excited lasers involve operation of modulator components in unconventional regimes. Reliable operation of switches and energy storage elements under high voltage and high di/dt conditions is a pacing item for laser development at the present time. To test and evaluate these components a Modulator Component Test Facility (MCTF) was constructed. The MCTF consists of a command charge system, energy storage capacitors, thyratron switch with inverse thyratron protection, and a resistive load. The modulator has initially been operated at voltages up to 60 kV at 600 Hz. Voltage, current, and calorimetric diagnostics are provided for major modulator components. Measurements of thyratron characteristics under high di/dt operation are presented. Commutation energy loss and di/dt have been measured as functions of the tube hydrogen pressure.
Date: May 11, 1981
Creator: Ball, D.; Hill, J. & Kan, T.
Object Type: Article
System: The UNT Digital Library
REACTOR CHEMISTRY DIVISION ANNUAL PROGRESS REPORT FOR PERIOD ENDING JANUARY 31, 1962 (open access)

REACTOR CHEMISTRY DIVISION ANNUAL PROGRESS REPORT FOR PERIOD ENDING JANUARY 31, 1962

Separate abstracts were prepared for thirty-one of the thirty-three sections. Of the sections not abstracted, the one entitled Fission Product Transport'' contained no information, the other, Transport of Noble Gases in Graphite'' is available in a more complete form as ORNLTM-I35 (NSA 16: 9209) (J.R.D.)
Date: May 11, 1962
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Laboratory Development of the Acid Thorex Process for Recovery of Consolidated Edison Thorium Reactor Fuel (open access)

Laboratory Development of the Acid Thorex Process for Recovery of Consolidated Edison Thorium Reactor Fuel

The id Thorex process, in which nitric acid is the salting'' agent in the solvent extraction of Th and U from an acid eficient feed with TBP in Amsco, was demonstrated in laboratory equipment for the recovery of synthetic Co solidated Edison Thorium Reactor fuel containing trace fission products. The acid was removed from solution of the declad fuel pellets to produce an acid deficient feed by steam stripping, and the adjusted feed was treated with bisulfite to decrease the extractability of fission products. The Th and U were extracted with 30% TBP in Amsco, and pregnant organic was scrubbed with dilute nitric acid to improve decontamination. Additional acid was added to the extraction section to increase the distribution oefficient of the Th, The Th and U could then be stripped ther simultaneously or separately. No difficulties were ound with either excessive reflux of acid or <0.3%. The co centrated aqueous waste was about 0.2 liter per kilog am of Th processed, about 1/10 of that from the aluminum n trate-salted process. Engineering studies showed that the stage height in the extraction column with the acid Thorex process was 2.1 ft compared with 4 ft with the aluminum-salted Thorex process. …
Date: May 11, 1962
Creator: Rainey, R. H. & Moore, J. G.
Object Type: Report
System: The UNT Digital Library
RADIATION EFFECTS IN GRAPHITE (open access)

RADIATION EFFECTS IN GRAPHITE

A review of radiation effects on graphite is presented. Included are discussions of the general relations of these effects with original structural properties, and details of radioinduced changes. Other discussions are devoted to stored energy, annealing, and future problems in the use of nuclear graphite. Data and illustrations concerning structure and radioinduced changes are included. (J.R.D.)
Date: May 11, 1962
Creator: Nightingale, R.E.
Object Type: Report
System: The UNT Digital Library
IMPROVED WIND AND TURBULENCE MEASUREMENTS USING A LOW-COST 3-D SONIC ANEMOMETER AT A LOW-WIND SITE (open access)

IMPROVED WIND AND TURBULENCE MEASUREMENTS USING A LOW-COST 3-D SONIC ANEMOMETER AT A LOW-WIND SITE

A year of data from sonic anemometer and mechanical wind sensors was analyzed and compared at a low-wind site. Results indicate that 15-minute average and peak 1-second wind speeds (u) from the sonic agree well with data derived from a co-located cup anemometer over a wide range of speeds. Wind direction data derived from the sonic also agree closely with those from a wind vane except for very low wind speeds. Values of standard deviation of longitudinal wind speed ({sigma}{sub u}) and wind direction fluctuations ({delta}{sub {theta}}) from the sonic and mechanical sensors agree well for times with u &gt; 2 ms{sup -1} but show significant differences with lower u values. The most significant differences are associated with the standard deviation of vertical wind fluctuations ({sigma}{sub w}): the co-located vertical propeller anemometer yields values increasingly less than those measured by the sonic anemometer as u decreases from 2.5 approaching 0 ms{sup -1}. The combination of u over-estimation and under-estimation of {sigma}{sub w} from the mechanical sensors at low wind speeds causes considerable under-estimation of the standard deviation of vertical wind angle fluctuations ({sigma}{sub {phi}}), an indicator of vertical dispersion. Calculations of {sigma}{sub {phi}} from sonic anemometer measurements are typically 5{sup …
Date: May 11, 2007
Creator: Bowen, B
Object Type: Report
System: The UNT Digital Library
U.S. Aims for Zero-Energy: Support for PV on New Homes (open access)

U.S. Aims for Zero-Energy: Support for PV on New Homes

As a market segment for solar photovoltaic (PV) adoption, new homes have a number of attractive attributes. Homebuyers can easily roll the cost of the PV system into their mortgage and, with rebates or other financial incentives, potentially realize an immediate net positive cash flow from the investment. PV system performance can be optimized by taking roof orientation, shading, and other structural factors into account in the design of new homes. Building-integrated photovoltaics (BIPV), which are subject to fewer aesthetic concerns than traditional, rack-mounted systems, are well-suited to new construction applications. In large new residential developments, costs can be reduced through bulk purchases and scale economies in system design and installation. Finally, the ability to install PV as a standard feature in new developments - like common household appliances - creates an opportunity to circumvent the high transaction costs and other barriers typically confronted when each individual homeowner must make a distinct PV purchase decision.
Date: May 11, 2006
Creator: Barbose, Galen; Wiser, Ryan & Bolinger, Mark
Object Type: Article
System: The UNT Digital Library
ELECTRON-SPIN-RESONANCE STUDIES ON PHOTO-SYNTHETIC MATERIALS (open access)

ELECTRON-SPIN-RESONANCE STUDIES ON PHOTO-SYNTHETIC MATERIALS

A number of organisms have been examined for their ability to produce electron-spin-resonance signals at low temperatures in response to illumination. The efficiency of the response is of the order of not less than 5%, and the wavelength for maximum response is generally slightly on the longer side of the wavelength of maximum absorption, with a minimum appearing at the wavelength of maximum absorption.
Date: May 11, 1960
Creator: Sogo, Power B.; Carter, Louise A. & Calvin, Melvin.
Object Type: Report
System: The UNT Digital Library
Experimental Determination of Apery-Like Identities forZeta(2n+2) (open access)

Experimental Determination of Apery-Like Identities forZeta(2n+2)

We document the discovery of two generating functions forzeta(2n+2), analogous to earlier work for zeta(2n+1) and zeta(4n+3),initiated by Koecher and pursued further by Borwein, Bradley andothers.
Date: May 11, 2005
Creator: Bailey, David H.; Borwein, Jonathan M. & Bradley, David M.
Object Type: Article
System: The UNT Digital Library
Accurate Method for Forward and Reverse Bias Curve Fitting of TPV I-V Data (open access)

Accurate Method for Forward and Reverse Bias Curve Fitting of TPV I-V Data

None
Date: May 11, 2006
Creator: Danielson, L. & Depoy, D.
Object Type: Report
System: The UNT Digital Library
Qualification of Automated Low-Field NMR Relaxometry for Quality Control of Polymers in a Production Setting (open access)

Qualification of Automated Low-Field NMR Relaxometry for Quality Control of Polymers in a Production Setting

Implementation of a low field time-domain NMR scanner as a diagnostic tool in the production of new polymer components is described in the context of qualification of a new QA/QC device. A study to determine the optimal experimental parameters was performed and a robotic autosampler was built to enable scanning of multiple pads. Relationships between T{sub 2} values and physical properties of DC745 slabs were investigated, and the appropriate sampling parameters for the production setting were determined. Two versions of a robotic autosampler were built, and for the component described here a fourth radial axis was required in addition to traditional X, Y, and Z movement to eliminate the large variability in T{sub 2} due to inconsistent sample coverage caused by complex rib geometry of the component. Data show that with appropriate choice of experimental conditions of the NMR detector and the detection geometry of the robotic autosampler, sufficient resolution of variations in crosslink density on the millimeter scale could be determined. All data to date demonstrates that low-field NMR devices are a feasible tool for use in production settings for non-destructive quality control of polymer components.
Date: May 11, 2007
Creator: Chinn, S; Cook-Tendulkar, A; Maxwell, R; Wheeler, H; Wilson, M & Xie, Z
Object Type: Article
System: The UNT Digital Library
Rapid, Absolute Calibration of X-ray Filters Employed By Laser-Produced Plasma Diagnostics (open access)

Rapid, Absolute Calibration of X-ray Filters Employed By Laser-Produced Plasma Diagnostics

The electron beam ion trap (EBIT) facility at the Lawrence Livermore National Laboratory is being used to absolutely calibrate the transmission efficiency of X-ray filters employed by diodes and spectrometers used to diagnose laser-produced plasmas. EBIT emits strong, discrete monoenergetic lines at appropriately chosen X-ray energies. X-rays are detected using the high-resolution EBIT calorimeter spectrometer (ECS), developed for LLNL at the NASA/Goddard Space Flight Center. X-ray filter transmission efficiency is determined by dividing the X-ray counts detected when the filter is in the line of sight by those detected when out of the line of sight. Verification of filter thickness can be completed in only a few hours, and absolute efficiencies can be calibrated in a single day over a broad range from about 0.1 to 15 keV. The EBIT calibration lab has been used to field diagnostics (e.g., the OZSPEC instrument) with fully calibrated X-ray filters at the OMEGA laser. Extensions to use the capability for calibrating filter transmission for the DANTE instrument on the National Ignition Facility are discussed.
Date: May 11, 2008
Creator: Brown, G. V.; Beiersdorfer, P.; Emig, J.; Frankel, M.; Gu, M. F.; Heeter, R. F. et al.
Object Type: Article
System: The UNT Digital Library
Mode-of-Action Uncertainty for Dual-Mode Carcinogens: A Bounding Approach for Naphthalene-Induced Nasal Tumors in Rats Based on PBPK and 2-Stage Stochastic Cancer Risk Models (open access)

Mode-of-Action Uncertainty for Dual-Mode Carcinogens: A Bounding Approach for Naphthalene-Induced Nasal Tumors in Rats Based on PBPK and 2-Stage Stochastic Cancer Risk Models

A relatively simple, quantitative approach is proposed to address a specific, important gap in the appr approach recommended by the USEPA Guidelines for Cancer Risk Assessment to oach address uncertainty in carcinogenic mode of action of certain chemicals when risk is extrapolated from bioassay data. These Guidelines recognize that some chemical carcinogens may have a site-specific mode of action (MOA) that is dual, involving mutation in addition to cell-killing induced hyperplasia. Although genotoxicity may contribute to increased risk at all doses, the Guidelines imply that for dual MOA (DMOA) carcinogens, judgment be used to compare and assess results obtained using separate 'linear' (genotoxic) vs. 'nonlinear' (nongenotoxic) approaches to low low-level risk extrapolation. However, the Guidelines allow the latter approach to be used only when evidence is sufficient t to parameterize a biologically based model that reliably o extrapolates risk to low levels of concern. The Guidelines thus effectively prevent MOA uncertainty from being characterized and addressed when data are insufficient to parameterize such a model, but otherwise clearly support a DMOA. A bounding factor approach - similar to that used in reference dose procedures for classic toxicity endpoints - can address MOA uncertainty in a way that avoids explicit modeling …
Date: May 11, 2007
Creator: Bogen, K T
Object Type: Report
System: The UNT Digital Library
Final Report (open access)

Final Report

Incubation services were provided to companies and inventors with products and technologies with clean or renewable energy market potential.
Date: May 11, 2005
Creator: Reeves, Richard E.
Object Type: Report
System: The UNT Digital Library
Zinc Single Crystal Deformation Experiments using a "6 Degrees of Freedom" Apparatus (open access)

Zinc Single Crystal Deformation Experiments using a "6 Degrees of Freedom" Apparatus

A new experimental technique to study crystallographic slip system activity in metallic single crystals deformed under a condition of uniaxial stress is applied to study the behavior of Zn single crystals. The experimental apparatus allows essentially unconstrained shape change of inherently anisotropic materials under a condition of uniaxial stress by allowing 3 translational and 3 rotational degrees of freedom during compression; hence we have named the experiment 6 degrees of freedom (6DOF). The experiments also utilize a 3-D digital image correlation system to measure full-field displacement fields, which are used to calculate strain and make direct observations of slip system activity. We show that the experimental results associated with a pristine zinc single crystal are precisely consistent with the theoretical predicted shape change (sample distortion) assuming that the most favored slip system on the basal plane is the only one that is active. Another experiment was performed on a processed and annealed Zn single crystal to investigate slip that is inconsistent with the critical resolved shear stress (CRSS) theory. These experiments on zinc illustrate the ability of the 6DOF experiment, together with image correlation (IC) data, to measure slip system activity with a high degree of fidelity.
Date: May 11, 2006
Creator: Lassila, D. H.; LeBlanc, M. M. & Florando, J. N.
Object Type: Article
System: The UNT Digital Library
Operating manual for the electrostatic glove-box prefilter installed inside the filter glove box No. 046 at Rocky Flats, Building 776 (open access)

Operating manual for the electrostatic glove-box prefilter installed inside the filter glove box No. 046 at Rocky Flats, Building 776

Objective of the evaluation is to evaluate the effectiveness of the electrostatic prefilter in prolonging the life of HEPA (high-efficiency particulate-air) filters. The theory of the electrostatic filter is reviewed, and Glove Box Number 046 is described in detail, followed by a description of the electrostatic prefilter used in the present application. Engineering drawings of the electrostatic prefilter are included. The procedure for evaluating the electrostatic prefilter includes the steps for conducting five different tests: evaluating (1) the HEPA filter alone, (2 and 3) the HEPA filter with a standard prefilter treated both as disposable and reusable, and (4 and 5) the HEPA filter with the electrostatic prefilter, again treated as disposable and reusable. Procedures for flowmeter calibrations and measurements of particle-size distributions are also included. Long-term maintenence of the system during the evaluation program is outlined, and estimates of component durability are given. An electrical engineering safety note describes the high-voltage operational hazard of the electrostatic prefilter and the testing of safety devices (the current-overload trip circuit, the filter-door-interlock system, and the current-limiting resistor).
Date: May 11, 1979
Creator: Bergman, W.; Kaifer, R. C.; Hebard, H. D.; Taylor, R. D.; Lum, B. Y.; Buttedahl, O. I. et al.
Object Type: Report
System: The UNT Digital Library
Nova Event Logging System (open access)

Nova Event Logging System

Nova is a 200 terawatt, 10-beam High Energy Glass Laser currently under construction at LLNL. This facility, designed to demonstrate the feasibility of laser driven inertial confinement fusion, contains over 5000 elements requiring coordinated control, data acquisition, and analysis functions. The large amounts of data that will be generated must be maintained over the life of the facility. Often the most useful but inaccessible data is that related to time dependent events associated with, for example, operator actions or experiment activity. We have developed an Event Logging System to synchronously record, maintain, and analyze, in part, this data. We see the system as being particularly useful to the physics and engineering staffs of medium and large facilities in that it is entirely separate from experimental apparatus and control devices. The design criteria, implementation, use, and benefits of such a system will be discussed.
Date: May 11, 1981
Creator: Calliger, R.J. & Suski, G.J.
Object Type: Article
System: The UNT Digital Library
Small t Physics at the TEVATRON Collider (open access)

Small t Physics at the TEVATRON Collider

The first physics run of the superconducting Tevatron Collider at Fermilab ended this morning. A status report will be presented on the progress of the small angle elastic scattering and total cross section experiment, E710. The goals of this experiment are to measure the total proton-antiproton cross section from ..sqrt..s = 300 to 2000 GeV, the slope of the diffraction peak and rho, the ratio of the real to imaginary part of the forward scattering amplitude, at these energies. 1 ref., 8 figs.
Date: May 11, 1987
Creator: Bertani, M.; Giacomalli, G.; Maleyran, R.; Manarin, A.; Amos, N.; DeSalvo, R. et al.
Object Type: Article
System: The UNT Digital Library
ATOMLLL: atoms with shading and highlights (open access)

ATOMLLL: atoms with shading and highlights

The ATOMS program, written at Bell Telephone Laboratory, is capable of determining the visible portions of a scene consisting of interpenetrating spheres and cylinders, put together to represent space-filling or ball-and-stick molecular models. The Lawrence Livermore Laboratory version contains enhancements to add shading and highlights, and to render the spheres on film as ellipses, so they will appear round when projected in various wide-screen formats. The visible parts of each sphere or cylinder are shaded by a minicomputer controlling the film recorder, thus releasing the main computer from transferring the millions of intensity values for each frame. The minicomputer is microprogrammed with an efficient algorithm for the intensities, which uses the color look-up tables in the film recorder to store the reflectance as a function of angle of incidence. 8 references.
Date: May 11, 1979
Creator: Max, N.L.
Object Type: Article
System: The UNT Digital Library
Object technology: A white paper (open access)

Object technology: A white paper

Object-Oriented Technology (OOT), although not a new paradigm, has recently been prominently featured in the trade press and even general business publications. Indeed, the promises of object technology are alluring: the ability to handle complex design and engineering information through the full manufacturing production life cycle or to manipulate multimedia information, and the ability to improve programmer productivity in creating and maintaining high quality software. Groups at a number of the DOE facilities have been exploring the use of object technology for engineering, business, and other applications. In this white paper, the technology is explored thoroughly and compared with previous means of developing software and storing databases of information. Several specific projects within the DOE Complex are described, and the state of the commercial marketplace is indicated.
Date: May 11, 1992
Creator: Jordan, S. R.; Arrowood, L. F.; Cain, W. D.; Stephens, W. M. & Vickers, B. D.
Object Type: Report
System: The UNT Digital Library
Equivalence of two formalisms for calculating higher order synchrotron sideband spin resonances (open access)

Equivalence of two formalisms for calculating higher order synchrotron sideband spin resonances

Synchrotron sideband resonances of a first order spin resonance are generally regarded as the most important higher order spin resonances in a high-energy storage ring. Yokoya's formula for these resonances is rederived, including some extra terms, which he neglected, but which turn out to be of comparable magnitude to the terms retained. Including these terms, Yokoya's formalism and the SMILE algorithm are shown to be equivalent to leading order in the resonance strengths. The theoretical calculations are shown to agree with certain measurements from SPEAR.
Date: May 11, 1988
Creator: Mane, S.R.
Object Type: Article
System: The UNT Digital Library
Full-scale demonstration Low-NO sub x Cell trademark Burner retrofit (open access)

Full-scale demonstration Low-NO sub x Cell trademark Burner retrofit

The Low-NO{sub x} Cell{trademark} Burner operates on the principle of staged combustion. The lower burner of each two-nozzle cell is modified to accommodate all the fuel input previously handled by two nozzles. Secondary air, less than theoretically required for complete combustion, is introduced to the lower burner. The remainder of secondary air is directed to the upper port'' of each cell to complete the combustion process. B W/EPRI have thoroughly tested the LNCB{trademark} at two pilot scales (6 million Btu per hour and 100 million Btu per hour), and tested a single full-scale burner in a utility boiler. Combustion tests at two scales have confirmed NO{sub x} reduction with the low-NO{sub x} cell on the order of 50% relative to the standard cell burner at optimum operating conditions. The technology is now ready for full unit, full-scale demonstration.
Date: May 11, 1992
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Computational method for realistic estimates of the dose to active marrow (open access)

Computational method for realistic estimates of the dose to active marrow

Calculation of absorbed dose to active marrow from photon radiation is a complex problem because electronic equilibrium may not exist in the vicinity of soft tissue-bone mineral interfaces. Snyder et al. recognized the intractable geometry of trabecular bone in their studies of photon transport in the body and formulated marrow dose estimates in a conservative manner. Other investigators have noted that this approach leads to overestimate by factors of 3 or more at low photon energy. In this paper the absorbed dose is formulated in terms of physical and anatomical parameters defining the energy deposition in the marrow space. 17 references, 2 figures, 1 table.
Date: May 11, 1984
Creator: Eckerman, K.F. & Cristy, M.
Object Type: Article
System: The UNT Digital Library
Effect of pretreating of host oil on coprocessing (open access)

Effect of pretreating of host oil on coprocessing

The principal objective of this research is to determine the role that host petroleum-derived oils (1000 [degree]F[sup +]), as that of catalytically treated host oils, play when used as liquefaction solvents in coprocessing with coal. The host oils will be extensively characterized and then pretreated in a number of ways which involve catalytic reactions such as hydrogenation, hydrocracking, and isomerization. The pretreated oils will then be characterized by elemental analysis, catalytic dehydrogenation, and NMR. The effects of the host oil on coprocessing with coal will be compared to those obtained using catalytically modified heavy oils. When appropriate, model compounds will be used to study specific reactions brought about by the pretreatments. A total of 18 pretreatment runs have been made on an AMOCO vacuum tower residuum, VTR, in an attempt to increase its hydrogen content from 10.2 wt % to a level of about 11.5%. This pretreatment resulted in a significant increase in the hydrogen content of the starting oil (10.2 wt % to 11.2%).
Date: May 11, 1993
Creator: Wender, I. & Tierney, J.W.
Object Type: Report
System: The UNT Digital Library
Internal dosimetry performing dose assessments via bioassay measurements (open access)

Internal dosimetry performing dose assessments via bioassay measurements

The Internal Dosimetry Department at the Y-12 Plant maintains a state-of-the-art bioassay program managed under the guidance and regulations of the Department of Energy. The two major bioassay techniques currently used at Y-12 are the in vitro (urinalysis) and in vivo (lung counting) programs. Fecal analysis (as part of the in vitro program) is another alternative; however, since both urine and fecal analysis provide essentially the same capabilities for detecting exposures to uranium, the urinalysis is the main choice primarily for aesthetic reasons. The bioassay frequency is based on meeting NCRP 87 objectives which are to monitor the accumulation of radioactive material in exposed individuals, and to ensure that significant depositions are detected.
Date: May 11, 1993
Creator: Bailey, K. M.
Object Type: Report
System: The UNT Digital Library