510 Matching Results

Search Results

Results: 1 - 24 next
open access

Experimental Determination of ETS Particle Deposition in a Low Ventilation Room

Description: Deposition on indoor surfaces is an important removal mechanism for tobacco smoke particles. We report measurements of deposition rates of environmental tobacco smoke particles in a room-size chamber. The deposition rates were determined from the changes in measured concentrations by correcting for the effects of coagulation and ventilation. The air flow turbulent intensity parameter was determined independently by measuring the air velocities in the chamber. Particles with diameters smaller th… more
Date: May 1, 1993
Creator: Xu, M.; Nematollahi, M.; Sextro, R. G.; Gadgil, A. J. & Nazaroff, W. W.
Partner: UNT Libraries Government Documents Department
open access

Space reactor fuel element testing in upgraded TREAT

Description: The testing of candidate fuel elements at prototypic operating conditions with respect to temperature, power density, hydrogen coolant flow rate, etc., a crucial component in the development and qualification of nuclear rocket engines based on the Particle Bed Reactor (PBR), NERVA-derivative, and other concepts. Such testing may be performed at existing reactors, or at new facilities. A scoping study has been performed to assess the feasibility of testing PBR based fuel elements at the TREAT re… more
Date: May 1, 1993
Creator: Todosow, M.; Bezler, P.; Ludewig, H. & Kato, W.Y.
Partner: UNT Libraries Government Documents Department
open access

Theoretical Crystallography With the Advanced Visualization System

Description: Space is an Application Visualization System (AVS) graphics module designed for crystallographic and molecular research. The program can handle molecules, two-dimensional periodic systems, and three-dimensional periodic systems, all referred to in the paper as models. Using several methods, the user can select atoms, groups of atoms, or entire molecules. Selections can be moved, copied, deleted, and merged. An important feature of Space is the crystallography component. The program allows the u… more
Date: May 1, 1993
Creator: Younkin, C. R.; Thornton, E. N.; Nicholas, J. B.; Jones, D. R. & Hess, A. C.
Partner: UNT Libraries Government Documents Department
open access

Dependence of [beta][center dot][tau] on plasma shape in DIII-D

Description: In this paper we discuss the observed variation in plasma performance with plasma shape, in particular, we shall compare single and double null diverted plasmas. The product [beta][center dot][tau] has been used as a figure-of-merit for comparing different toroidal magnetic configurations. Here we shall use it as the figure-of-merit for comparing differing configurations within the DIII-D tokamak.
Date: May 1, 1993
Creator: Lazarus, E.A. (Oak Ridge National Lab., TN (United States))
Partner: UNT Libraries Government Documents Department
open access

DOE/NREL Advanced Wind Turbine Development Program

Description: The development of technologically advanced, high-efficiency wind turbines continues to be a high-priority activity of the US wind industry. The National Renewable Energy Laboratory (formerly the Solar Energy Research Institute), sponsored by the US Department of Energy (DOE), has initiated the Advanced Wind Turbine Program to assist the wind industry in the development of a new class of advanced wind turbines. The initial phase of the program focused on developing conceptual designs for near-t… more
Date: May 1, 1993
Creator: Butterfield, C.P.; Smith, B.; Laxson, A.; Thresher, B. (National Renewable Energy Lab., Golden, CO (United States)) & Goldman, P. (USDOE Assistant Secretary for Conservation and Renewable Energy, Washington, DC (United States). Wind/Hydro/Ocean Technologies Div.)
Partner: UNT Libraries Government Documents Department
open access

Experience with the Source Evaluation Board method of procuring technical components for the Fermilab Main Injector

Description: Fermilab has adopted the Source Evaluation Board (SEB) method for procuring certain major technical components of the Fermilab Main Injector. The SEB procedure is designed to ensure the efficient and effective expenditure of Government funds at the same time that it optimizes the opportunity for attainment of project objectives. A qualitative trade-off is allowed between price and technical factors. The process involves a large amount of work and is only justified for a very limited number of p… more
Date: May 1, 1993
Creator: Harding, D. J.; Collins, J. P.; Kobliska, G. R.; Chester, N. S.; Pewitt, E. G. & Fowler, W. B.
Partner: UNT Libraries Government Documents Department
open access

Studies of interactions between conducting polymer and organic vapors, applications to chemical sensing

Description: In order to understand the physicochemical mechanism involved in the organic semiconductor charge-transfer processes occurring upon doping of the films with vapor molecules different experimental approaches much be taken. The effect of vapor diffusion into the electrochemically deposited poly(pyrrole), PP and poly(N-vinylcarbazole), PNVCz, films was investigated by monitoring the mass change of the exposed polymer, absorbance changes in the absorption spectra, and the work function change due t… more
Date: May 1, 1993
Creator: Josowicz, M.; Topart, P. & Cabala, R.
Partner: UNT Libraries Government Documents Department
open access

Low-temperature sintering and phase changes in chromite interconnect materials

Description: Sintering shrinkage curves and phase changes were compared for calcium-substituted lanthanum chromates with either slight Asite enrichment or depletion. Of the former type, La[sub 0.7]Ca[sub 0.31],CrO[sub 3] that was synthesized by the glycine-nitrate method sintered to high density in air at 1250C, exhibiting two rapid-shrinkage events. Weight loss measurements corroborated XRD data showing that, prior to densiflcation, over half the Ca resided in non-perovskite phases, including CaCrO[sub 4].… more
Date: May 1, 1993
Creator: Chick, L. A.; Armstrong, T. R.; McCready, D. E.; Coffey, G. W.; Maupin, G. D. & Bates, J. L.
Partner: UNT Libraries Government Documents Department
open access

Impedance budget and beam stability analysis of the Fermilab Main Injector

Description: The impedance budget of the Fermilab Main Injector (MI) is estimated, which includes the contributions from the resistive walls, bellows, rf cavities, steps, Lambertsons, etc. Beam stability during ramping and bunch coalescence is analyzed. The transverse resistive-wall coupled bunch growth is found to be somewhat worse than the situation in the Main Ring (MR).
Date: May 1, 1993
Creator: Martens, M. A. & Ng, K. Y.
Partner: UNT Libraries Government Documents Department
open access

The design and performance of a high sensitivity loss monitor system for use in the Fermilab antiproton rings

Description: As part of a general laboratory cleanup of hazardous materials from the accelerator enclosures we have replaced the liquid scintillator based paint can type beam loss monitors with improved loss monitors based on plastic centiliter. This paper describes the design of these counters and their performance in the PBAR source.
Date: May 1, 1993
Creator: Halling, A. M.; Zagel, J. R. & Hahn, A.
Partner: UNT Libraries Government Documents Department
open access

Observation of the coalescing of beam into an asymmetric rf bucket by stochastic cooling

Description: Antiprotons in the debuncher ring at Fermilab have been observed to be bunched outside of the barrier bucket'' when cooled to small [Delta]p/p with the stochastic cooling. This bunching occurs in the same location as a very small stable bucket in the RF wave form. The stochastic cooling appears to be causing beam that is originally uniformly distributed to be captured by this stable bucket.
Date: May 1, 1993
Creator: Halling, A. M. & Lu, Xian Ping
Partner: UNT Libraries Government Documents Department
open access

TESLA vertical test dewar cryogenic and mechanical design

Description: Collaborators on the design of a Tevatron Superconducting Linear Accelerator (TESLA) are working toward construction of a test cell consisting of four full length cryostats, 12 meters long, each containing eight, 9-cell superconducting rf cavities. In order to ensure that each cavity meets its performance requirements, [open quote]as received[close quote] structures will be tested in a vertical dewar prior to installation in the cryostat vessels. In addition, the dewar system will accommodate c… more
Date: May 1, 1993
Creator: Nicol, T. H.; Arnold, D. E. & Champion, M. S.
Partner: UNT Libraries Government Documents Department
open access

NMR measurement of pore structure

Description: An attempt was made to pursue [sup 129]Xe NMR as a pore measurement technique. Samples studied were synthetic imogolite (tubular aluminosilicate with gibbsite structure), sodium Y-zeolite, and an aerogel and a xerogel. Gases used were normal Xe, [sup 13]CO[sub 2], and [sup 15]N[sub 2]. Although a completely general NMR technique for measuring pore size distributions may not be possible, information about molecular motion and interactions can be obtained, because NMR is sensitive to short range … more
Date: May 31, 1993
Creator: Earl, W.L. (Los Alamos National Lab., NM (United States)); Kim, Yong-Wah (Los Alamos National Lab., NM (United States) New Mexico Univ., Albuquerque, NM (United States). Center for Microengineered Ceramics) & Smith, D.M. (New Mexico Univ., Albuquerque, NM (United States). Center for Microengineered Ceramics)
Partner: UNT Libraries Government Documents Department
open access

Simulation of enhanced tokamak performance on DIII-D using fast wave current drive

Description: The fast magnetosonic wave is now recognized to be a leading candidate for noninductive for the tokamak reactor due to the ability of the wave to penetrate to the hot dense core region. Fast wave current drive (FWCD) experiments on D3D have realized up to 120 kA of rf current drive, with up to 40% of the plasma current driven noninductively. The success of these experiments at 60 MHZ with a 2 MW transmitter source capability has led to a major upgrade of the FWCD system. Two additional transmit… more
Date: May 1, 1993
Creator: deGrassie, J. S.; Lin-Liu, Y. R. Petty, C. C.; Pinsker, R. I.; Chan, V. S.; Prater, R.; St. John, H. (General Atomics, San Diego, CA (United States)) et al.
Partner: UNT Libraries Government Documents Department
open access

Workshop on coatings needs in the auto industry

Description: New lightweight materials continue to be of great interest to the automotive industry. Compared to 20 years ago, the average vehicle weight has been reduced by almost a fourth, and fuel economy has nearly doubled. While continued improvements are both desirable and possible, materials choices are narrowing and the manufacturing methods needed to produce advanced materials systems are much more costly. The incentives remain high, however; particularly in view of large payoffs associated with min… more
Date: May 1, 1993
Creator: Courtright, E.L.
Partner: UNT Libraries Government Documents Department
open access

Process performance of Ahlstrom Pyroflow PCFB pilot plant

Description: Ahlstrom Pyropower has designed and built a 10 MW[sub th] (34 MMBtu) pressurized circulating fluidized bed (PCFB) pilot plant in Karhula, Finland. The unit is now operating. Data from this unit supports the design of a nominal 80 MW, Des Moines Energy Center 1 (DMEC-1) PCFB Repowering Project. The pilot plant PCFB combustor is of square cross-section. It is housed in a 3.6 m (11.8 ft) diameter pressure vessel. A high pressure high temperature gas cleaning unit downstream of the PCFB exhaust is … more
Date: May 1, 1993
Creator: Sellakumar, K.M. (R D Center, Ahlstrom Pyropower, Inc., San Diego, CA (United States)); Isaksson, J. & Tiensuu, J. (Ahlstroem Pyropower, Inc., Karhula (Finland). Hans Ahlstroem Lab.)
Partner: UNT Libraries Government Documents Department
open access

Reflective coatings for solar applications

Description: Many applications of solar energy require large mirrors to provide high levels of concentrated sunlight. The success of such conversion systems hinges on the optical durability and economic viability of the reflector materials. A major effort at the National Renewable Energy Laboratory (NREL) has been to improve the existing reflector materials technology and to identify candidates that retain optical performance and durability criteria and offer potential for reduced cost. To attain the goals,… more
Date: May 1, 1993
Creator: Jorgensen, G.
Partner: UNT Libraries Government Documents Department
open access

A scintillating fiber beam halo detector for heavy ion beam diagnostics

Description: A prototype beam halo detector of scintillating Fibers has been designed in order to detect beam halo problems at an early stage in the tuning process. The results of initial characterization of the fibers are presented and issues of electronics and readout discussed.
Date: May 1, 1993
Creator: McMahan, M. A.; Assang, A.; Herr, S.; McCormack, F.; Krebs, G. & Feinberg, B.
Partner: UNT Libraries Government Documents Department
open access

A study of the role of homogeneous process in heterogeneous high explosives

Description: In a new hydrodynamic formulation of shock-induced chemical reaction, we can show formally that the presence of certain homogenous reaction characteristics is becoming more evident as shock pressure increase even in heterogeneous high explosives. The homogeneous reaction pathway includes nonequilibrium excitation and deactivation stages prior to chemical reaction. The excitation process leads to an intermediate state at higher energy level than the equilibrium state, and as a result, the effect… more
Date: May 1, 1993
Creator: Tang, P. K.
Partner: UNT Libraries Government Documents Department
open access

Ecological investigation of a hazardous waste site, Warner Robins, Georgia

Description: Landfill No. 4 and the sludge lagoon at Robins Air Force Base, Warner Robins, Georgia, were added to the United States Environmental Protection Agency (EPA) National Priorities List in 1987 because of highpotential for contaminant migration. Warner Robins is located approximately 90 miles southeast of Atlanta. In 1990 CH2M HILL conducted a Remedial Investigation at the base that recommended that further ecological assessment investigations be conducted (CH2M HILL 1990). The subject paper is the… more
Date: May 1, 1993
Creator: Wade, M. & Billig, P.
Partner: UNT Libraries Government Documents Department
open access

Synthesis of ceramic oxide powders in a microwave plasma device

Description: Synthesizing oxide ceramic powders by application of a microwave plasma is of great advantage. The microwave plasma can be used two ways: To act as a source of heat for the pyrolysis of solutions and to excite gas phase reactions to obtain nanosized powders. Both applications are superior to standard methods. A microwave cavity well suited for these experiments and its operating characteristics are described. Using a microwave plasma as a source of heat for pyrolytic decomposition of nitrates i… more
Date: May 1, 1993
Creator: Vollath, D. & Sickafus, K. E.
Partner: UNT Libraries Government Documents Department
open access

Radiological hazard classification of DOE facilities by DOE STD-1027-92: LANL nuclear facility list

Description: Los Alamos facilities containing significant radiological hazards have been reclassified according to DOE-SID 1027-92, a recently issued guide for hazard classification. DOE-STD 1027-92 was provided in support of DOE Order 5480.23 to identify which facilities would be governed under DOE 5480.23 requirements; these would presumably be called nuclear facilities. This new classification has affected the original list of 18 LANL nuclear facilities by increasing it to 39. It has also lowered the cla… more
Date: May 1, 1993
Creator: Elder, J. C.
Partner: UNT Libraries Government Documents Department
Back to Top of Screen