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Site susceptibility to leaching by H/sub 2/SO/sub 4/ in acid rainfall

Description: One of the major concerns about the terrestrial effects of acid rainfall has been the leaching of nutrient cations from forest soils and the consequences of this to forest growth. A concept that has proven useful in assessing soil leaching due to acid rainfall and many other manipulations is that of anion mobility in the soil. This concept does not consider cation exchange reactions directly, but the sum of cations must balance the sum of anions, in meq/l, in the soil solution. Total ionic leac… more
Date: January 1, 1978
Creator: Johnson, D. W.
Partner: UNT Libraries Government Documents Department
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Effects of CO{sub 2} and nitrogen fertilization on soils planted with ponderosa pine

Description: The effects of elevated CO{sub 2} (ambient, 525, and 700 {micro}l l{sup -1})and N fertilization (0, 10, and 20 g N m{sup 2} yr{sup -1}) on soil pCO{sub 2}, CO{sub 2} efflux, soil solution chemistry, and soil C and nutrients in an open-top chamber study with Pinus ponderosa are described. Soil pCO{sub 2} and CO{sub 2} efflux were significantly greater with elevated CO{sub 2}, at first (second growing season) in the 525 {micro}l l{sup -1} and later (fourth and fifth growing seasons) in the 700 {m… more
Date: December 1, 1996
Creator: Johnson, D.W.
Partner: UNT Libraries Government Documents Department
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Chemical Characteristics of Two Forested Ultisols and Two Forested Inceptisols Relevant to Anion Production and Mobility

Description: As a prelude to a basic program on soil leaching, some chemical characteristics of two forested Ultisols in eastern Tennessee and two forested Inceptisols in western Washington are discussed in relation to the production and mobility of anions. These soils were chosen in an attempt to provide a range of free iron (Fe) and aluminum (Al) contents (which are hypothesized to be related to anion adsorption) and carbon:nitrogen (C:N) ratios (which are hypothesized to be related to nitrate and bicarbo… more
Date: January 17, 2001
Creator: Johnson, D.W.
Partner: UNT Libraries Government Documents Department
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Environmental and plant effects of sewage sludge application to forests and pastures

Description: Digested sewage sludge was applied to pastures and tree plantations at 19 to 44 Mg/ha (dry weight) as part of a municipal sludge disposal program. The sludge had low concentrations of heavy metals and traces of /sup 137/Cs and /sup 60/Co. Monitoring of soils, soil solutions, and runoff indicated that N, P, heavy metals, and radionuclides were largely retained in the upper 15cm of the soil. Soil solutions had elevated NO/sub 3//sup /minus// concentrations often >100 mg/L, but no significant incr… more
Date: January 1, 1989
Creator: Van Miegroet, H.; Boston, H.L. & Johnson, D.W.
Partner: UNT Libraries Government Documents Department
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The status of alpha-particle diagnostics

Description: There is a flurry of activity to complete alpha-particle diagnostics so that they can undergo some experimental testing in DT plasmas on JET or TFTR prior to implementation on ITER. Successful measurements of escaping charged fusion products have been made in DD plasmas, and the {alpha}-particle source can be well characterized by neutron profile measurement. These methods can be extrapolated to DT plasmas. Measurement of the confined {alpha}-particles requires a new technique. Collective Thoms… more
Date: January 1, 1992
Creator: Young, K. M. & Johnson, D. W.
Partner: UNT Libraries Government Documents Department
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Simulated effects of elevated CO{sub 2} on nitrogen cycling using the NuCM model

Description: The interactions between elevated CO{sub 2} and N cycling were explored using simulations generated by the Nutrient Cycling Model (NuCM) for a Pinus taeda site at Duke, North Carolina and a mixed deciduous site at Walker Branch, Tennessee. The simulations tested whether N limitation would prevent growth increase in response to elevated CO{sub 2} and whether growth response to CO{sub 2} in N-limited systems could be facilitated by increased biomass/N (reduced concentration) and/or increased litt… more
Date: October 14, 1998
Creator: Johnson, D.W.
Partner: UNT Libraries Government Documents Department
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Recent D-T results on TFTR

Description: Routine tritium operation in TFTR has permitted investigations of alpha particle physics in parameter ranges resembling those of a reactor core. ICRF wave physics in a DT plasma and the influence of isotopic mass on supershot confinement have also been studied. Continued progress has been made in optimizing fusion power production in TFTR, using extended machine capability and Li wall conditioning. Performance is currently limited by MHD stability. A new reversed magnetic shear regime is being … more
Date: October 1, 1995
Creator: Johnson, D.W.; Arunasalam, V. & Barnes, C.W.
Partner: UNT Libraries Government Documents Department
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Electron Density Measurements in the National Spherical Torus Experiment Detached Divertor Region Using Stark Broadening of Deuterium Infrared Paschen Emission Lines

Description: Spatially resolved measurements of deuterium Balmer and Paschen line emission have been performed in the divertor region of the National Spherical Torus Experiment using a commercial 0.5 m Czerny-Turner spectrometer. While the Balmer emission lines, Balmer and Paschen continua in the ultraviolet and visible regions have been extensively used for tokamak divertor plasma temperature and density measurements, the diagnostic potential of infrared Paschen lines has been largely overlooked. We analyz… more
Date: April 27, 2007
Creator: Soukhanovskii, V A; Johnson, D W; Kaita, R & Roquemore, A L
Partner: UNT Libraries Government Documents Department
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Radiation shielding for TFTR DT diagnostics

Description: The authors illustrate the designs of radiation shielding for the TFTR DT diagnostics using the ACX and TVTS systems as specific examples. The main emphasis here is on the radiation transport analyses carried out in support of the designs. Initial results from the DT operation indicate that the diagnostics have been functioning as anticipated and the shielding designs are satisfactory. The experience accumulated in the shielding design for the TFTR DT diagnostics should be useful and applicable… more
Date: July 1, 1994
Creator: Ku, L. P.; Johnson, D. W. & Liew, S. L.
Partner: UNT Libraries Government Documents Department
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Tritium diagnostics by Balmer-alpha emission

Description: Spectral line emission from tritium in a plasma may be distinguished from deuterium emission by a small isotope shift. A diagnostic system to measure tritium Balmer-alpha emission from the plasma edge has been installed on TFTR. This system has been used in deuterium plasmas, and the deuterium alpha line profile used as a basis to predict the spectrum at differing tritium concentrations in future D-T runs. The tritium and deuterium lines are partially blended, however, analysis of the predicted… more
Date: February 1, 1993
Creator: Skinner, C. H.; Ramsey, A. T.; Johnson, D. W. & Diesso, M.
Partner: UNT Libraries Government Documents Department
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Brief communication: evidence that B lymphocytes carry the nuclear pocket abnormality associated with bovine leukemia virus infection

Description: Peripheral blood lymphocytes from three cows with persistent lymphocytosis were separated on nylon wool columns into nylon wool adherent and nonadherent populations. The percentage of cells coated with surface immunoglobulin and the frequency of lymphocytic nuclear pockets in each subpopulation were then determined. In each case the adherent population consisted predominantly of B cells with an increased nuclear pocket frequency while the non-adherent cells were 98 to 99 percent surface immunog… more
Date: January 1, 1976
Creator: Pomeroy, K. A.; Paul, P. S.; Weber, A. F.; Sorensen, D. K. & Johnson, D. W.
Partner: UNT Libraries Government Documents Department
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Tritium diagnostics by Balmer-alpha emission

Description: Spectral line emission from tritium in a plasma may be distinguished from deuterium emission by a small isotope shift. A diagnostic system to measure tritium Balmer-alpha emission from the plasma edge has been installed on TFTR. This system has been used in deuterium plasmas, and the deuterium alpha line profile used as a basis to predict the spectrum at differing tritium concentrations in future D-T runs. The tritium and deuterium lines are partially blended, however, analysis of the predicted… more
Date: February 1, 1993
Creator: Skinner, C. H.; Ramsey, A. T.; Johnson, D. W. & Diesso, M.
Partner: UNT Libraries Government Documents Department
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Gas injection in PLT: experimental overview

Description: Cold gas injection serves both the obvious role of a particle source at the surface of the plasma and a more subtle role as one element in the process by which the relative impurity concentration and the MHD activity of a discharge are determined. Evidence offered by PLT experiments in support of these two widely recognized roles is considered.
Date: January 1, 1977
Creator: Schmidt, G. L.; Bretz, N. I.; Hawryluk, R. J.; Hosea, J. C. & Johnson, D. W.
Partner: UNT Libraries Government Documents Department
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APD detector electronics for the NSTX Thomson scattering system

Description: An electronics system has been installed and tested for the readout of APD detectors for the NSTX Thomson scattering system. Similar to previous designs, it features preamps with a fast and a slow output. The fast output uses pulse shaping to optimize sensitivity for the 8 nsec scattered light pulse while rejecting noise in the intrinsic plasma background. A low readout noise of {approximately}25 photoelectrons is achieved at an APD gain of 75. The design incorporates a number of features to pr… more
Date: August 7, 2000
Creator: Johnson, D. W.; LeBlanc, B. P.; Long, D. L. & Renda, G.
Partner: UNT Libraries Government Documents Department
open access

Effects of CO{sub 2} and nitrogen fertilization on growth and nutrient content of juvenile ponderosa pine

Description: This data set presents measured values of plant diameter and height, biomass of plant components, and nutrient (carbon, nitrogen, phosphorus, sulfur, potassium, calcium, magnesium, boron, copper, iron, manganese, and zinc) concentrations from a study of the effects of carbon dioxide and nitrogen fertilization on ponderosa pine (Pinus ponderosa Dougl. ex Laws.) conducted in open-top chambers in Placerville, California, from 1991 through 1996. This data set contains values from 1991 through 1993.
Date: March 1, 1998
Creator: Johnson, D. W.; Ball, J. T.; Walker, R. F. & Cushman, R. M.
Partner: UNT Libraries Government Documents Department
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An Edge Rotation and Temperature Diagnostic on NSTX

Description: A new diagnostic for the National Spherical Torus Experiment (NSTX) is described whose function is to measure ion rotation and temperature at the plasma edge. The diagnostic is sensitive to C III, C IV, and He II intrinsic emission, covering a radial region of 15 cm at the extreme edge of the outboard midplane. Thirteen chords are distributed between toroidal and poloidal views, allowing the toroidal and poloidal rotation and temperature of the plasma edge to be simultaneously measured with 10 … more
Date: August 29, 2003
Creator: Biewer, T. M.; Bell, R. E.; Feder, R.; Johnson, D. W. & Palladino, R. W.
Partner: UNT Libraries Government Documents Department
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Plasma turbulence imaging using high-power laser Thomson scattering

Description: The 2-D structure of plasma density turbulence in a magnetically confined plasma can potentially be measured using a Thomson scattering system made from components of the Nova laser of LLNL. For a plasma such as NSTX at PPPL, the laser would form an {approximately}10 cm wide plane sheet beam passing vertically through the chamber across the magnetic field. The scattered light would be imaged by a CCD camera viewing along the direction of the magnetic field. The laser energy required to make 2-D… more
Date: June 8, 2000
Creator: Zweben, S. J.; Caird, J.; Davis, W.; Johnson, D. W. & LeBlanc, B. P.
Partner: UNT Libraries Government Documents Department
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Resource utilization efficiency improvement of geothermal binary cycles: Phase I. Annual report, June 15, 1975--June 15, 1976

Description: The following were performed: (1) evaluation of the advantages and disadvantages of the use of mixtures as working fluids in geothermal binary cycles, (2) development of a geothermal binary cycle simulation computer program capable of both mixture and pure fluid cycle simulation, (3) development of an accurate thermodynamic properties computer program package (applicable as a minimum to hydrocarbon mixture and pure fluid cycles), (4) comparison of mixture and pure fluid cycles, including relati… more
Date: January 1, 1976
Creator: Starling, K. E.; Fish, L. W.; West, H.; Johnson, D. W.; Iqbal, K. Z.; Lee, C. O. et al.
Partner: UNT Libraries Government Documents Department
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Observations Concerning the Injection of a Lithium Aerosol into the Edge of TFTR Discharges

Description: A new method of actively modifying the plasma-wall interaction was tested on the Tokamak Fusion Test Reactor. A laser was used to introduce a directed lithium aerosol into the discharge scrape-off layer. The lithium introduced in this fashion ablated and migrated preferentially to the limiter contact points. This allowed the plasma-wall interaction to be influenced in situ and in real time by external means. Significant improvement in energy confinement and fusion neutron production rate as wel… more
Date: December 13, 2000
Creator: Mansfield, D.K.; Johnson, D.W.; Grek, B.; Kugel, H.; Bell, M.G. & al, et
Partner: UNT Libraries Government Documents Department
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Operation of the NSTX Thomson Scattering System

Description: The NSTX multi-point Thomson scattering system has been in operation for nearly two years and provides routine Te(R,t) and ne(R,t) measurements. The laser beams from two 30-Hz Nd:YAG lasers are imaged by a spherical mirror onto 36 fiber-optics bundles. In the present configuration, the output ends of 20 of these bundles are instrumented with filter polychromators and avalanche photodiode detectors. In this paper, we discuss the laser implementation and the installed collection optics. We follow… more
Date: September 3, 2002
Creator: LeBlanc, B. P.; Bell, R. E.; Johnson, D. W.; Hoffman, D. E.; Long, D. C. & Palladino, R. W.
Partner: UNT Libraries Government Documents Department
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Measurement of loss of DT fusion products using scintillator detectors in TFTR

Description: A poloidal array of MeV ion loss probes previously used to measure DD fusion product loss has been upgraded to measure the loss of alpha particles from DT plasmas in TFTR. The following improvements to the system have been made in preparation for the use of tritium in TFTR: (1) relocation of detectors to a neutronshielded enclosure in the basement to reduce neutron-induced background signals; (2) replacement of ZnS:Cu (P31) scintillators in the probes with the Y{sub 3}Al{sub 5}0{sub 12}:Ce(P46)… more
Date: March 1, 1995
Creator: Darrow, D. S.; Herrmann, H. W.; Johnson, D. W.; Marsala, R. J.; Palladino, R. W.; Zweben, S. J. et al.
Partner: UNT Libraries Government Documents Department
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Scale length study in TFTR (Tokamak Fusion Test Reactor)

Description: The scale lengths of the electron density (L/sub n//sub e/), temperature (L/sub T//sub e/), and pressure (L/sub p//sub e/) gradients were investigated during the 1985 operating period of the Tokamak Fusion Test Reactor (TFTR) for gas-fueled plasmas with neutral beam injection and movable limiter. Although the global energy confinement time degrades as the heating power increases or the plasma current decreases, the radial profiles of the scale lengths (L/sub T//sub e/ and L/sup p//sub e/) remai… more
Date: December 1, 1988
Creator: Hiroe, S.; Goldston, R. J.; Bitter, M.; Bush, C. E.; Efthimion, P. C.; Grek, B. et al.
Partner: UNT Libraries Government Documents Department
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Evolution of the electron temperature profile of ohmically heated plasmas in TFTR

Description: Blackbody electron cyclotron emission was used to ascertain and study the evolution and behavior of the electron temperature profile in ohmically heated plasmas in the Tokamak Fusion Test Reactor (TFTR). The emission was measured with absolutely calibrated millimeter wavelength radiometers. The temperature profile normalized to the central temperature and minor radius is observed to broaden substantially with decreasing limiter safety factor q/sub a/, and is insensitive to the plasma minor radi… more
Date: August 1, 1985
Creator: Taylor, G.; Efthimion, P. C.; Arunasalam, V.; Goldston, R. J.; Grek, B.; Hill, K. W. et al.
Partner: UNT Libraries Government Documents Department
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