Neoclassical transport of energetic minority tail ions generated by ion-cyclotron resonance heating in tokamak geometry (open access)

Neoclassical transport of energetic minority tail ions generated by ion-cyclotron resonance heating in tokamak geometry

Neoclassical transport of energetic minority tail ions, which are generated by high powered electromagnetic waves of the Ion Cyclotron Range of Frequencies (ICRF) at the fundamental harmonic resonance, is studied analytically in tokamak geometry. The effect of Coulomb collisions on the tail ion transport is investigated in the present work. The total tail ion transport will be the sum of the present collision-driven transport and the wave-driven transport, which is due to the ICRF-wave scattering of the tail particles as reported in the literature. The transport coefficients have been calculated kinetically, and it is found that the large tail ion viscosity, driven by the localized ICRF-heating and Coulomb slowing-down collisions, induces purely convective particle transport of the tail species, while the energy transport is both convective and diffusive. The rate of radial particle transport is shown to be usually small, but the rate of radial energy transport is larger and may not be negligible compared to the Coulomb slowing-down rate. 18 refs., 2 figs.
Date: January 1, 1990
Creator: Chang, C.S. (New York Univ., NY (USA). Courant Inst. of Mathematical Sciences); Hammett, G.W. & Goldston, R.J. (Princeton Univ., NJ (USA). Plasma Physics Lab.)
Object Type: Report
System: The UNT Digital Library
An assessment of the lifetime of Faraday shield elements (open access)

An assessment of the lifetime of Faraday shield elements

The interaction of plasma with rf fields from an ion cyclotron range of frequencies (ICRF) antenna has been studied to estimate the amount of Faraday shield erosion expected in normal ICRF heating operation. Plasma parameters and ion energies have been measured in the near field of an antenna and used in a model to estimate the erosion rate of the Faraday shield surface. Experiments were conducted on the RF Test Facility, a magnetic mirror device at Oak Ridge National Laboratory, using a single-strap resonant loop antenna with a two-tier Faraday shield. The outer tier, facing the plasma, was layered with graphite tiles. The antenna was operated at currents and voltages within 50% of those expected in tokamaks. The time-varying floating potential was measured with a capacitively coupled probe, and the time-averaged floating potential, electron temperature, and electron density were measured with a Langmuir probe. Ion energies were measured with a gridded energy analyser located below the antenna, and samples of silicon were placed on the Faraday shield surface to estimate the incident ion energy. The capacitive probe measurements show that the rf floating potential follows the magnetic field pattern of the antenna, indicating that the electromagnetic fields are responsible for …
Date: January 1, 1990
Creator: Caughman, J. B. O., II; Ruzic, D. N.; Hoffman, D. J.; Langley, R. A.; Lewis, M. B. & Ryan, P. M.
Object Type: Article
System: The UNT Digital Library
Scouting, Volume 78, Number 1, January-February 1990 (open access)

Scouting, Volume 78, Number 1, January-February 1990

Bi-monthly publication of the Boy Scouts of America, written for Boy Scout leaders, officials, and others interested in the work of the Scouts. It includes articles about events and activities, updates from the national headquarters, topical columns and essays, and news from various chapters nationwide.
Date: January 1990
Creator: Boy Scouts of America
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Artificial life: The coming evolution (open access)

Artificial life: The coming evolution

Within fifty to a hundred years a new class of organisms is likely to emerge. These organisms will be artificial in the sense that they will originally be designed by humans. However, they will reproduce, and will evolve into something other than their initial form; they will be alive'' under any reasonable definition of the word. These organisms will evolve in a fundamentally different manner than contemporary biological organisms, since their reproduction will be under at least partial conscious control, giving it a Lamarckian component. The pace of evolutionary change consequently will be extremely rapid. The advent of artificial life will be the most significant historical event since the emergence of human beings. The impact on humanity and the biosphere could be enormous, larger than the industrial revolution, nuclear weapons, or environmental pollution. We must take steps now to shape the emergence of artificial organisms; they have potential to be either the ugliest terrestrial disaster, or the most beautiful creation of humanity. 22 refs., 3 figs.
Date: January 1, 1990
Creator: Farmer, J.D. (Los Alamos National Lab., NM (USA) Santa Fe Inst., NM (USA)) & Belin, A.d'A. (Shute, Mihaly, and Weinberger, Santa Fe, NM (USA))
Object Type: Article
System: The UNT Digital Library
Mechanical properties of cables exposed to simultaneous thermal and radiation aging (open access)

Mechanical properties of cables exposed to simultaneous thermal and radiation aging

Sandia National Laboratories is conducting long-term aging research on representative samples of nuclear power plant Class 1E cables. The objectives of this program are to determine the suitability of these cables for extended life (beyond the 40-year design basis) and to assess various cable condition monitoring (CM) techniques for predicting remaining cable life. This paper provides the results of mechanical measurements that were performed on cable specimens cross-linked polyethylene neoprene jackets: chlorinated polyethylene jackets, fiberglass braid jackets, and chlorosulfonated polyethylene jackets aged at relatively mild, simultaneous thermal and radiation exposure conditions for periods of up to nine months. After aging, some of the aged samples, as well as some unaged samples, were exposed to accident gamma radiation at ambient temperature. The mechanical measurements discussed in this paper include tensile strength, ultimate elongation, and compressive modulus. 10 refs., 22 figs., 2 tabs.
Date: January 1, 1990
Creator: Jacobus, M.J. (Sandia National Labs., Albuquerque, NM (USA)) & Fuehrer, G.F. (Science and Engineering Associates, Inc., Albuquerque, NM (USA))
Object Type: Article
System: The UNT Digital Library
De Leon Free Press (De Leon, Tex.), Vol. 102, No. 34, Ed. 1 Thursday, January 18, 1990 (open access)

De Leon Free Press (De Leon, Tex.), Vol. 102, No. 34, Ed. 1 Thursday, January 18, 1990

Weekly newspaper from De Leon, Texas that includes local, state, and national news along with advertising.
Date: January 18, 1990
Creator: Wilkerson, Gayle E.
Object Type: Newspaper
System: The Portal to Texas History
De Leon Free Press (De Leon, Tex.), Vol. 102, No. 35, Ed. 1 Thursday, January 25, 1990 (open access)

De Leon Free Press (De Leon, Tex.), Vol. 102, No. 35, Ed. 1 Thursday, January 25, 1990

Weekly newspaper from De Leon, Texas that includes local, state, and national news along with advertising.
Date: January 25, 1990
Creator: Wilkerson, Gayle E.
Object Type: Newspaper
System: The Portal to Texas History
The Big Lake Wildcat (Big Lake, Tex.), Vol. SIXTY-FIFTH YEAR, No. 1, Ed. 1 Thursday, January 4, 1990 (open access)

The Big Lake Wildcat (Big Lake, Tex.), Vol. SIXTY-FIFTH YEAR, No. 1, Ed. 1 Thursday, January 4, 1990

Weekly newspaper from Big Lake, Texas that includes local, state and national news along with advertising.
Date: January 4, 1990
Creator: Werst, David
Object Type: Newspaper
System: The Portal to Texas History
The Big Lake Wildcat (Big Lake, Tex.), Vol. SIXTY-FIFTH YEAR, No. 3, Ed. 1 Thursday, January 18, 1990 (open access)

The Big Lake Wildcat (Big Lake, Tex.), Vol. SIXTY-FIFTH YEAR, No. 3, Ed. 1 Thursday, January 18, 1990

Weekly newspaper from Big Lake, Texas that includes local, state and national news along with advertising.
Date: January 18, 1990
Creator: Werst, David
Object Type: Newspaper
System: The Portal to Texas History
Altus Times (Altus, Okla.), Vol. 68, No. 14, Ed. 1 Tuesday, January 16, 1990 (open access)

Altus Times (Altus, Okla.), Vol. 68, No. 14, Ed. 1 Tuesday, January 16, 1990

Daily newspaper from Altus, Oklahoma that includes local, state, and national news along with advertising.
Date: January 16, 1990
Creator: Lomenick, Rick
Object Type: Newspaper
System: The Gateway to Oklahoma History
Altus Times (Altus, Okla.), Vol. 68, No. 22, Ed. 1 Thursday, January 25, 1990 (open access)

Altus Times (Altus, Okla.), Vol. 68, No. 22, Ed. 1 Thursday, January 25, 1990

Daily newspaper from Altus, Oklahoma that includes local, state, and national news along with advertising.
Date: January 25, 1990
Creator: Lomenick, Rick
Object Type: Newspaper
System: The Gateway to Oklahoma History
Altus Times (Altus, Okla.), Vol. 68, No. 27, Ed. 1 Wednesday, January 31, 1990 (open access)

Altus Times (Altus, Okla.), Vol. 68, No. 27, Ed. 1 Wednesday, January 31, 1990

Daily newspaper from Altus, Oklahoma that includes local, state, and national news along with advertising.
Date: January 31, 1990
Creator: Lomenick, Rick
Object Type: Newspaper
System: The Gateway to Oklahoma History
Altus Times (Altus, Okla.), Vol. 68, No. 9, Ed. 1 Wednesday, January 10, 1990 (open access)

Altus Times (Altus, Okla.), Vol. 68, No. 9, Ed. 1 Wednesday, January 10, 1990

Daily newspaper from Altus, Oklahoma that includes local, state, and national news along with advertising.
Date: January 10, 1990
Creator: Lomenick, Rick
Object Type: Newspaper
System: The Gateway to Oklahoma History
Journal-Capital (Pawhuska, Okla.), Vol. 80, No. 4, Ed. 1 Saturday, January 13, 1990 (open access)

Journal-Capital (Pawhuska, Okla.), Vol. 80, No. 4, Ed. 1 Saturday, January 13, 1990

Semiweekly newspaper from Pawhuska, Oklahoma that includes local, state, and national news along with advertising.
Date: January 13, 1990
Creator: Strahan, Treva
Object Type: Newspaper
System: The Gateway to Oklahoma History
Altus Times (Altus, Okla.), Vol. 68, No. 10, Ed. 1 Thursday, January 11, 1990 (open access)

Altus Times (Altus, Okla.), Vol. 68, No. 10, Ed. 1 Thursday, January 11, 1990

Daily newspaper from Altus, Oklahoma that includes local, state, and national news along with advertising.
Date: January 11, 1990
Creator: Lomenick, Rick
Object Type: Newspaper
System: The Gateway to Oklahoma History
A study of non-uniqueness and instability for convex materials (open access)

A study of non-uniqueness and instability for convex materials

There are stability analyses of two-dimensional plane shock waves which show the existence of unstable shock fronts for some equations of state. We present numerical evidence that these unstable two-dimensional shocks are also unstable in one dimension, at least in the sense that the Lax-Friedrichs difference scheme does not have a steady asymptotic traveling wave connecting the shocked and unshocked states. When there is instability there are also multiple solutions of the Riemann problem. In the typical case of two stable solutions and one unstable one, which of the stable ones is selected seems to depend on mesh size or the initial profile. If there is a physical selection principle, Lax-Friedrichs does not obey it. 11 refs., 13 figs.
Date: January 1, 1990
Creator: Wendroff, B.
Object Type: Article
System: The UNT Digital Library
Altus Times (Altus, Okla.), Vol. 68, No. 16, Ed. 1 Thursday, January 18, 1990 (open access)

Altus Times (Altus, Okla.), Vol. 68, No. 16, Ed. 1 Thursday, January 18, 1990

Daily newspaper from Altus, Oklahoma that includes local, state, and national news along with advertising.
Date: January 18, 1990
Creator: Lomenick, Rick
Object Type: Newspaper
System: The Gateway to Oklahoma History
Altus Times (Altus, Okla.), Vol. 68, No. 17, Ed. 1 Friday, January 19, 1990 (open access)

Altus Times (Altus, Okla.), Vol. 68, No. 17, Ed. 1 Friday, January 19, 1990

Daily newspaper from Altus, Oklahoma that includes local, state, and national news along with advertising.
Date: January 19, 1990
Creator: Lomenick, Rick
Object Type: Newspaper
System: The Gateway to Oklahoma History
Altus Times (Altus, Okla.), Vol. 68, No. 11, Ed. 1 Friday, January 12, 1990 (open access)

Altus Times (Altus, Okla.), Vol. 68, No. 11, Ed. 1 Friday, January 12, 1990

Daily newspaper from Altus, Oklahoma that includes local, state, and national news along with advertising.
Date: January 12, 1990
Creator: Lomenick, Rick
Object Type: Newspaper
System: The Gateway to Oklahoma History
Altus Times (Altus, Okla.), Vol. 68, No. 15, Ed. 1 Wednesday, January 17, 1990 (open access)

Altus Times (Altus, Okla.), Vol. 68, No. 15, Ed. 1 Wednesday, January 17, 1990

Daily newspaper from Altus, Oklahoma that includes local, state, and national news along with advertising.
Date: January 17, 1990
Creator: Lomenick, Rick
Object Type: Newspaper
System: The Gateway to Oklahoma History
Altus Times (Altus, Okla.), Vol. 68, No. 18, Ed. 1 Sunday, January 21, 1990 (open access)

Altus Times (Altus, Okla.), Vol. 68, No. 18, Ed. 1 Sunday, January 21, 1990

Daily newspaper from Altus, Oklahoma that includes local, state, and national news along with advertising.
Date: January 21, 1990
Creator: Lomenick, Rick
Object Type: Newspaper
System: The Gateway to Oklahoma History
Jewish Herald-Voice (Houston, Tex.), Vol. 81, No. 43, Ed. 1 Thursday, January 25, 1990 (open access)

Jewish Herald-Voice (Houston, Tex.), Vol. 81, No. 43, Ed. 1 Thursday, January 25, 1990

Weekly Jewish newspaper from Houston, Texas that includes local, state, and national news along with advertising.
Date: January 25, 1990
Creator: Samuels, Jeanne F.
Object Type: Newspaper
System: The Portal to Texas History
Altus Times (Altus, Okla.), Vol. 68, No. 13, Ed. 1 Monday, January 15, 1990 (open access)

Altus Times (Altus, Okla.), Vol. 68, No. 13, Ed. 1 Monday, January 15, 1990

Daily newspaper from Altus, Oklahoma that includes local, state, and national news along with advertising.
Date: January 15, 1990
Creator: Lomenick, Rick
Object Type: Newspaper
System: The Gateway to Oklahoma History
Altus Times (Altus, Okla.), Vol. 68, No. 21, Ed. 1 Wednesday, January 24, 1990 (open access)

Altus Times (Altus, Okla.), Vol. 68, No. 21, Ed. 1 Wednesday, January 24, 1990

Daily newspaper from Altus, Oklahoma that includes local, state, and national news along with advertising.
Date: January 24, 1990
Creator: Lomenick, Rick
Object Type: Newspaper
System: The Gateway to Oklahoma History