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Nancy Black: Continuing the Fight

Description: This article is a short biography of Nancy Black describing her background and how she ended up in journalism, writing news at several outlets and later starting her own paper, the White Rock Lake Weekly.
Date: Autumn 2018
Creator: Moore, Brianna
Partner: UNT Frank W. and Sue Mayborn School of Journalism
open access

Steepened magnetosonic waves in the high. beta. plasma surrounding Comet Giacobini-Zinner

Description: We extend the previous studies of intense hydromagnetic waves at Giacobini-Zinner to investigate the mode and direction of wave propagation. Simultaneous high-resolution measurements of electron density fluctuations demonstrate that the long period (approx.100 s) waves are propagating in the magnetosonic mode. Principal axis analyses of the long period waves and accompanying partial rotations show that the sum of the wave phase rotations is 360/sup 0/C, indicating that both are parts of the sam… more
Date: January 1, 1986
Creator: Tsurutani, B. T.; Smith, E. J.; Thorne, R. M.; Gosling, J. T. & Matsumoto, H.
Partner: UNT Libraries Government Documents Department
open access

Experimental evaluation of a fixed collector employing vee-trough concentrator and vacuum tube receivers

Description: A test bed for experimental evaluation of a fixed solar collector which combines an evacuated glass tube solar receiver with a flat plate/black chrome plated copper absorber and an asymmetric veetrough concentrator was designed and constructed. Earlier predictions of thermal performance were compared with test data acquired for a bare vacuum tube receiver; and receiver tubes with Alzak aluminum, aluminized FEP Teflon film laminated sheet metal and second surface ordinary mirror reflectors. Test… more
Date: January 1, 1977
Creator: Selcuk, M. K.
Partner: UNT Libraries Government Documents Department
open access

SP-100, a project manager`s view. Technical information report

Description: Born to meet the special needs of America`s space effort, the SP-100 Program testifies to the cooperation among government agencies. The Department of Energy (DOE), the National Aeronautics and Space Administration (NASA), and the Defense Advanced Research Projects Agency (DARPA) are working together to produce a 100-kW power system for use in outer space. At this point in the effort, it is appropriate to review: The approach to meet program goals; the status of activities of the Project Office… more
Date: December 1, 1983
Creator: Truscello, V. C.
Partner: UNT Libraries Government Documents Department
open access

External flow radiators for reduced space powerplant temperatures. Technical information report

Description: Nuclear space powerplants can operate at temperatures below 900 K and use stainless steel construction without a weight penalty if new radiator concepts can achieve radiator weights of 1-3 kg/m{sup 2}. Conventional tube-and-fin radiators weight about 10 kg/m{sup 2} because of heavy tube walls to prevent meteroid puncture. Radiator designs that do not require meteroid protection are possible; they operate with fluids of low vapor pressure that can be exposed directly to space in external-flow ra… more
Date: January 1, 1984
Creator: Elliott, D. G.
Partner: UNT Libraries Government Documents Department
open access

Reversible thermodynamic cycle for AMTEC power conversion

Description: The thermodynamic cycle appropriate to an AMTEC (alkali metal thermal-to-electric converter) cell is discussed for both liquid- and vapor-fed modes of operation, under the assumption that all processes can be performed reversibly. In the liquid-fed mode, the reversible efficiency is greater than 89.6% of Carnot efficiency for heat input and rejection temperatures (900--1300 K and 400--800 K, respectively) typical of practical devices. Vapor-fed cells can approach the efficiency of liquid-fed ce… more
Date: July 1, 1992
Creator: Vining, C. B.; Williams, R. M.; Underwood, M. L.; Ryan, M. A. & Suitor, J. W.
Partner: UNT Libraries Government Documents Department
open access

Design considerations for a fiber optic communications network for power systems

Description: The design of a fiber optic communication network for monitoring and control in power systems is discussed. It is shown that by appropriate choice of protocols, a fault-tolerant system can be built that operates in any arbitrary configuration. Since the network is based on fiber optics, it can be made fast enough for substation monitoring and control. In this application, a relatively small number of cables is required to implement a high reliability system. The network can also be used for dis… more
Date: August 1, 1993
Creator: Kirkham, H.; Johnston, A. R. & Allen, G. D.
Partner: UNT Libraries Government Documents Department
open access

Efficiency of an AMTEC recirculating test cell, experiments and projections

Description: The alkali metal thermal to electric converter (AMTEC) is an electrochemical device for the direct conversion of heat to electrical energy with efficiencies potentially near Carnot. The future usefulness of AMTEC for space power conversion depends on the efficiency of the devices. Systems studies have projected from 15% to 35% thermal to electric conversion efficiencies, and one experiment has demonstrated 19% efficiency for a short period of time. Recent experiments in a recirculating test cel… more
Date: May 1, 1992
Creator: Underwood, M. L.; O`Connor, D.; Williams, R. M.; Jeffries-Nakamura, B. & Ryan, M. A.
Partner: UNT Libraries Government Documents Department
open access

Activated transport in AMTEC electrodes

Description: Transport of alkali metal atoms through porous cathodes of alkali metal thermal-to-electric converter (AMTEC) cells is responsible for significant, reducible losses in the electrical performance of these cells. Experimental evidence for activated transport of metal atoms at grain surfaces and boundaries within some AMTEC electrodes has been derived from temperature dependent studies as well as from analysis of the detailed frequency dependence of ac impedance results for other electrodes, inclu… more
Date: July 1, 1992
Creator: Williams, R. M.; Jeffries-Nakamura, B.; Ryan, M. A.; Underwood, M. L.; O`Connor, D. & Kikkert, S.
Partner: UNT Libraries Government Documents Department
open access

A 2D electrostatic PIC code for the Mark III Hypercube

Description: We have implemented a 2D electrostastic plasma particle in cell (PIC) simulation code on the Caltech/JPL Mark IIIfp Hypercube. The code simulates plasma effects by evolving in time the trajectories of thousands to millions of charged particles subject to their self-consistent fields. Each particle`s position and velocity is advanced in time using a leap frog method for integrating Newton`s equations of motion in electric and magnetic fields. The electric field due to these moving charged partic… more
Date: December 31, 1990
Creator: Ferraro, R. D.; Liewer, P. C. & Decyk, V. K.
Partner: UNT Libraries Government Documents Department
open access

Dynamic load balancing in a concurrent plasma PIC code on the JPL/Caltech Mark III hypercube

Description: Dynamic load balancing has been implemented in a concurrent one-dimensional electromagnetic plasma particle-in-cell (PIC) simulation code using a method which adds very little overhead to the parallel code. In PIC codes, the orbits of many interacting plasma electrons and ions are followed as an initial value problem as the particles move in electromagnetic fields calculated self-consistently from the particle motions. The code was implemented using the GCPIC algorithm in which the particles ar… more
Date: December 31, 1990
Creator: Liewer, P. C.; Leaver, E. W.; Decyk, V. K. & Dawson, J. M.
Partner: UNT Libraries Government Documents Department
open access

Advances in high temperature components for AMTEC (alkali metal thermal-to-electric converter)

Description: Long lifetimes are required for AMTEC (or sodium heat engine) components for aerospace and terrestrial applications, and the high heat input temperature as well as the alkali metal liquid and vapor environment places unusual demands on the materials used to construct AMTEC devices. In addition, it is important to maximize device efficiency and power density, while maintaining a long life capability. In addition to the electrode, which must provide both efficient electrode kinetics, transport of… more
Date: December 31, 1991
Creator: Williams, R. M.; Jeffries-Nakamura, B.; Underwood, M. L.; Ryan, M. A.; O`Connor, D. & Kikkert, S.
Partner: UNT Libraries Government Documents Department
open access

[Denton Record-Chronicle articles, June 10, 1990]

Description: A clipping of an article by Susan Shelton for the Denton Record-Chronicle about the new NTIEVA program's reworking of art education in Metroplex schools. Another piece by Shelton that is included covers Dr. Warren Carver's support of the program.
Date: June 10, 1990
Creator: Shelton, Susan
Partner: UNT Libraries Special Collections
open access

[The Dallas Morning News, 'Museum director resigns']

Description: An article written by Janet Kutner for The Dallas Morning News that announces the resignation of E. A. Carmean Jr. as director of the Modern Art Museum of Fort Worth. The piece covers the work he did while at the museum.
Date: 199X
Creator: Kutner, Janet
Partner: UNT Libraries Special Collections
open access

Plasma properties of driver gas following interplanetary shocks observed by ISEE-3

Description: Plasma fluid parameters calculated from solar wind and magnetic field data obtained on ISEE 3 were studied to determine the characteristic properties of driver gas following interplanetary shocks. Of 54 shocks observed from August 1978 to February 1980, 9 contained a well defined driver gas that was clearly identifiable by a discontinuous decrease in the average proton temperature across a tangential discontinuity. While helium enhancements were present in all of 9 of these events, only about h… more
Date: January 1, 1982
Creator: Zwickl, R. D.; Asbridge, J. R.; Bame, S. J.; Feldman, W. C.; Gosling, J. T. & Smith, E. J.
Partner: UNT Libraries Government Documents Department
open access

Dual arm master controller concept

Description: The Advanced Servomanipulator (ASM) slave was designed with an anthropomorphic stance, gear/torque tube power drives, and modular construction. These features resulted in increased inertia, friction, and backlash relative to tape-driven manipulators. Studies were performed which addressed the human factors design and performance trade-offs associated with the corresponding master controller best suited for the ASM. The results of these studies, as well as the conceptual design of the dual arm m… more
Date: January 1, 1984
Creator: Kuban, D.P. & Perkins, G.S.
Partner: UNT Libraries Government Documents Department
open access

Space nuclear power system and the design of the nuclear electric propulsion OTV

Description: Payload increases of three to five times that of the Shuttle/Centaur can be achieved using nuclear electric propulsion. Various nuclear power plant options being pursued by the SP-100 Program are described. These concepts can grow from 100 kW/sub e/ to 1MW/sub e/ output. Spacecraft design aspects are addressed, including thermal interactions, plume interactions, and radiation fluences. A baseline configuration is described accounting for these issues. Safety aspects of starting the OTV transfer… more
Date: January 1, 1984
Creator: Buden, D. & Garrison, P.W.
Partner: UNT Libraries Government Documents Department
open access

The P/Giacobini-Zinner Magnetotail

Description: On September 11, 1985 the International Cometary Explorer passed behind Comet Giacobini-Zinner with a closest approach distance of 7800 km. In agreement with Alfven's interplanetary magnetic field line draping model of cometary type I tails, a well defined 1 x 10/sup 4/ km diameter magnetotail was observed downstream of the inner coma. This study uses the ICE magnetic field, plasma electron, plasma wave, and energetic ion observations to investigate the structure and stability of the Giacobini-… more
Date: January 1, 1986
Creator: Slavin, J. A.; Smith, E. J.; Daly, P. W.; Flammer, K. R.; Gloeckler, G.; Goldberg, B. A. et al.
Partner: UNT Libraries Government Documents Department
open access

The comet Giacobini-Zinner magnetotail: Axial stresses and inferred near-nucleus properties

Description: Utilizing the electron and magnetic field data from the ICE tail traversal of Comet Giacobini-Zinner along with the MHD equations, we have developed a steady state, stress balance model of the cometary magnetotail. With it we infer many important but unmeasured ion properties within the G-Z magnetotail both at ICE and upstream at the average point along each streamline where cometary ions are picked-up. The derived tailward ion flow speed at ICE is quite constant at approx.-20 to -30 km/sec acr… more
Date: October 1, 1986
Creator: McComas, D. J.; Gosling, J. T.; Bame, S. J.; Slavin, J. A.; Smith, E. J. & Steinberg, J. L.
Partner: UNT Libraries Government Documents Department
open access

MHD waves detected by ice at distances > 28 x 10/sup 6/ km from Comet Halley: Cometary or solar wind origin

Description: Spectral analyses of the high resolution magnetic field data are employed to determine if there is evidence of cometary heavy ion pickup when ICE was closest to Halley, approx.28 x 10/sup 6/ km. No evidence is found for the presence of heavy ion cyclotron waves. However, from this search, two new wave modes are discovered in the solar wind: electromagnetic ion cyclotron waves and drift mirror mode waves. Both modes have scales of 10 to 60 s (1 to 6 T/sub p/) in the spacecraft frame. The possibi… more
Date: January 1, 1986
Creator: Tsurutani, B. T.; Brinca, A. L.; Smith, E. J.; Thorne, R. M.; Scarf, F. L.; Gosling, J. T. et al.
Partner: UNT Libraries Government Documents Department
open access

Interplanetary propulsion using inertial fusion

Description: Inertial fusion can be used to power spacecraft within the solar system and beyond. Such spacecraft have the potential for short-duration manned-mission performance exceeding other technologies. We are conducting a study to assess the systems aspects of inertial fusion as applied to such missions, based on the conceptual engine design of Hyde (1983) we describe the required systems for an entirely new spacecraft design called VISTA that is based on the use of DT fuel. We give preliminary design… more
Date: January 1, 1987
Creator: Orth, C.D.; Hogan, W.J.; Hoffman, N.; Murray, K.; Klein, G. & Diaz, F.C.
Partner: UNT Libraries Government Documents Department
open access

The VISTA spacecraft: Advantages of ICF (Inertial Confinement Fusion) for interplanetary fusion propulsion applications

Description: Inertial Confinement Fusion (ICF) is an attractive engine power source for interplanetary manned spacecraft, especially for near-term missions requiring minimum flight duration, because ICF has inherent high power-to-mass ratios and high specific impulses. We have developed a new vehicle concept called VISTA that uses ICF and is capable of round-trip manned missions to Mars in 100 days using A.D. 2020 technology. We describe VISTA's engine operation, discuss associated plasma issues, and descri… more
Date: October 2, 1987
Creator: Orth, C.D.; Klein, G.; Sercel, J.; Hoffman, N.; Murray, K. & Chang-Diaz, F.
Partner: UNT Libraries Government Documents Department
open access

Transport vehicle for manned Mars missions powered by inertial confinement fusion

Description: Inertial confinement fusion (ICF) is an ideal engine power source for manned spacecraft to Mars because of its inherently high power-to-mass ratios and high specific impulses. We have produced a concept for a vehicle powered by ICF and utilizing a magnetic thrust chamber to avoid plasma thermalization with wall structures and the resultant degradation of specific impulse that are unavoidable with the use of mechanical thrust chambers. This vehicle is capable of 100-day manned Mars missions with… more
Date: June 26, 1987
Creator: Orth, C.D.; Klein, G.; Sercel, J.; Hoffman, N.; Murray, K. & Chang-Diaz, F.
Partner: UNT Libraries Government Documents Department
open access

Generation of a strong core-centering force in a submillimeter compound droplet system

Description: By amplitude-modulating the driving voltage of an acoustic levitating apparatus, a strong core-centering force can be generated in a submillimeter compound droplet system suspended by the radiation pressure in a gaseous medium. Depending on the acoustic characteristics of the droplet system, it has been found that the technique can be utilized advantageously in the multiple-layer coating of an inertial-confinement-fusion pellet.
Date: January 1, 1981
Creator: Lee, M. C.; Feng, I.; Elleman, D. D.; Wang, T. G. & Young, A. T.
Partner: UNT Libraries Government Documents Department
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