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Dynamic Conductance of Carbon Nanotubes

Description: Article on dynamic conductance of carbon nanotubes.
Date: March 27, 2000
Creator: Roland, Christopher; Buongiorno Nardelli, Marco; Wang, Jian & Guo, Hong
Partner: UNT College of Arts and Sciences
open access

MAXIMA-1: A Measurement of the Cosmic Microwave Background Anisotropy on Angular Scales of 10' to 5 Degrees

Description: We present a map and an angular power spectrum of the anisotropy of the cosmic microwave background (CMB) from the first flight of MAXIMA. MAXIMA is a balloon-borne experiment with an array of 16 bolometric photometers operated at 100 mK. MAXIMA observed a 124 deg region of the sky with 10' resolution at frequencies of 150, 240 and 410 GHz. The data were calibrated using in-flight measurements of the CMB dipole anisotropy. A map of the CMB anisotropy was produced from three 150 and one 240 GHz … more
Date: October 2, 2000
Creator: Ade, P.; Balbi, A.; Bock, J.; Borrill, J.; Boscaleri, A.; deBernardis, P. et al.
Partner: UNT Libraries Government Documents Department
open access

Structure and Effects of Extended Defects in Polycrystalline Si Thin Films

Description: The structure and effects of extended defects in rapid deposited polycrystalline Si thin films were studied using a combination of high-resolution transmission electron microscopy and first-principles total energy calculations.
Date: January 1, 2000
Creator: Yan, Y.; Al-Jassim, M. M.; Wang, T. H. & Ciszek, T. F.
Partner: UNT Libraries Government Documents Department
open access

Mercury Removal at Idaho National Engineering and Environmental Laboratory's New Waste Calcining Facility

Description: Technologies were investigated to determine viable processes for removing mercury from the calciner (NWCF) offgas system at the Idaho National Engineering and Environmental Laboratory. Technologies for gas phase and aqueous phase treatment were evaluated. The technologies determined are intended to meet EPA Maximum Achievable Control Technology (MACT) requirements under the Clean Air Act and Resource Conservation and Recovery Act (RCRA). Currently, mercury accumulation in the calciner off-gas s… more
Date: March 1, 2000
Creator: Ashworth, Samuel Clay; Wood, R. A.; Taylor, D. D. & Sieme, D. D.
Partner: UNT Libraries Government Documents Department
open access

Utility bill comprehension in the commercial and industrial sector: results of field research

Description: This paper presents the results of interviews conducted with 44 business people in 10 states to examine the use of the utility bill as an information mechanism for providing businesses with the relationship between energy consumption and cost. Our results indicate that there are significant barriers to the use of the utility bill as an information tool for energy consumers. Furthermore, we found significant variations among respondents in the information desired from the bill, and differences i… more
Date: June 2, 2000
Creator: Payne, Christopher T.
Partner: UNT Libraries Government Documents Department
open access

Algorithm for Rapid Tomography of Gas Concentrations

Description: We present a new computed tomography method, the low third derivative (LTD) method, that is particularly suited for reconstructing the spatial distribution of gas concentrations from path-integral data for a small number of optical paths. The method finds a spatial distribution of gas concentrations that (1) has path integrals that agree with measured path integrals, and (2) has a low third spatial derivative in each direction, at every point. The trade-off between (1) and (2) is controlled by … more
Date: June 27, 2000
Creator: Price, P. N.; Fischer, M. L.; Gadgil, A. J. & Sextro, R. G.
Partner: UNT Libraries Government Documents Department
open access

Chopping effect observed at cathodic arc initiation

Description: This article is about the Chopping effect observed at cathodic arc initiation. It is argued that current chopping at the rising edge is similar to the current chopping effect that is well-known for the arc current approaching current-zero.
Date: October 1, 2000
Creator: Anders, Andre
Partner: UNT Libraries Government Documents Department
open access

High Intensity Ion Beam Injection Into the 88-Inch Cyclotron

Description: Low cross section experiments to produce super-heavyelements have increased the demand for high intensity heavy ion beams atenergies of about 5 MeV/nucleon at the 88-Inch Cyclotron at the LawrenceBerkeley National Laboratory. Therefore, efforts are underway to increasethe overall ion beam transmission through the axial injection line andthe cyclotron. The ion beam emittance has been measured for various ionmasses and charge states. Beam transport simulations including spacecharge effects were p… more
Date: May 31, 2000
Creator: Wutte, Daniela; Clark, Dave J.; Laune, Bernard; Leitner,Matthaeus A. & Lyneis, Claude M.
Partner: UNT Libraries Government Documents Department
open access

Cooperative sentry vehicles and differential GPS leapfrog

Description: As part of a project for the Defense Advanced Research Projects Agency, Sandia National Laboratories Intelligent Systems and Robotics Center is developing and testing the feasibility of using a cooperative team of robotic sentry vehicles to guard a perimeter, perform a surround task, and travel extended distances. This paper describes the authors most recent activities. In particular, this paper highlights the development of a Differential Global Positioning System (DGPS) leapfrog capability th… more
Date: June 7, 2000
Creator: Feddema, John T.; Lewis, Christopher L. & LaFarge, Robert A.
Partner: UNT Libraries Government Documents Department
open access

Prospecting for lunar ice using a multi-rover cooperative team

Description: A multi-rover cooperative team or swarm developed by Sandia National Laboratories is described, including various control methodologies that have been implemented to date. How the swarm's capabilities could be applied to a lunar ice prospecting mission is briefly explored. Some of the specific major engineering issues that must be addressed to successfully implement the swarm approach to a lunar surface mission are outlined, and potential solutions are proposed.
Date: February 11, 2000
Creator: Klarer, Paul R.; Feddema, John T. & Lewis, Christopher L.
Partner: UNT Libraries Government Documents Department
open access

Modeling of an inductive adder kicker pulser for DARHT-II

Description: An all solid-state kicker pulser for a high current induction accelerator (the Dual-Axis Radiographic Hydrodynamic Test facility DARHT-2) has been designed and fabricated. This kicker pulser uses multiple solid state modulators stacked in an inductive-adder configuration. Each modulator is comprised of multiple metal-oxide-semiconductor field-effect transistors (MOSFETs) which quickly switch the energy storage capacitors across a magnetic induction core. Metglas is used as the core material to … more
Date: September 25, 2000
Creator: Wang, L.; Caporaso, G. J. & Cook, E. G.
Partner: UNT Libraries Government Documents Department
open access

Structure of Cool Flame Fronts of Pentane, Iso-Pentane and Their Mixture

Description: An experimental study of the combustion of two isomers of pentane, n-pentane and iso-pentane, in laminar cool flames has been carried out. Three flames were studied, one with n-pentane, the second with iso-pentane, and the third with an equimolar mixture of the two isomers. Particular attention has been given to the low temperature region ahead of the hot region of the flame and the cool flame chemistry occurring there. A unique experimental facility has been used to provide access to this cool… more
Date: January 11, 2000
Creator: Mansurov, Z A; Mironenko, A A; Bodykov, D U; Rakhimetkaliev, K N & Westbrook, C K
Partner: UNT Libraries Government Documents Department
open access

Use of Imperfect Calibration for Seismic Location

Description: Efforts to more effectively monitor nuclear explosions include the calibration of travel times along specific paths. Benchmark events are used to improve travel-time prediction by (1) improving models, (2) determining travel times empirically, or (3) using a hybrid approach. Even velocity models that are determined using geophysical analogy (i.e. models determined without the direct use of calibration data) require validation with calibration events. Ideally, the locations and origin times of c… more
Date: July 12, 2000
Creator: Myers, S C & Schultz, C A
Partner: UNT Libraries Government Documents Department
open access

NLC photon collider option progress and plans

Description: The idea of producing beams of high energy photons by Compton backscattering of laser photons was proposed over 20 years ago. At the time, producing the required laser pulses was not feasible. However, recent advances in high average power, diode pumped lasers appear to have solved this problem. The US Collaboration is now turning its attention to the engineering requirement of mating the laser and optics components with the accelerator structures in the confined space of the a colliding beam i… more
Date: August 31, 2000
Creator: Gronberg, J.
Partner: UNT Libraries Government Documents Department
open access

Material transfer system in support of the plutonium immobilization program

Description: The Plutonium Immobilization Program requires development of the process and plant prototypic equipment to immobilize surplus plutonium in ceramic for long-term storage. Because of the hazardous nature of plutonium, it was necessary to develop a remotely operable materials transfer system which can function within the confines of a glovebox. In support of this work at LLNL, such a material transfer system (MTS) was developed. This paper presents both the mechanical and controls parts making up … more
Date: December 20, 2000
Creator: Pak, D
Partner: UNT Libraries Government Documents Department
open access

Graph based multilevel algorithms for preconditioning finite element problems

Description: This paper discusses: (1) A general block-factorization (matrix) form of multilevel preconditioners; algebraic methods; (2) Selecting parameters based on the matrix topology; graph based algorithms; (3) Examples of coarsening; (4) Numerical experiments.
Date: March 24, 2000
Creator: Vassilevski, P S
Partner: UNT Libraries Government Documents Department
open access

Synthesis and Characterization of Porous Hydroxyapatite and Hydroxyapatite Coatings

Description: A technique is developed to construct bulk hydroxyapatite (HAp) with different cellular structures. The technique involves the initial synthesis of nanocrystalline hydroxyapatite powder from an aqueous solution using water-soluble compounds and then followed by spray drying into agglomerated granules. The granules were further cold pressed and sintered into bulks at elevated temperatures. The sintering behavior of the HAp granules was characterized and compared with those previously reported. R… more
Date: October 25, 2000
Creator: Nieh, T. G.; Choi, B. W. & Jankowski, Alan Frederic
Partner: UNT Libraries Government Documents Department
open access

Relative x-ray backlighter intensity comparison of ti and ti/sc combination foils driven in double-sided and single-sided laser configuration

Description: Use of multiple backlighter foils and/or double-sided laser interaction geometry with backlit imaging can result in improved backlighter efficiency. An experimental comparison of backlighter intensity for Ti foils and Ti/Sc combination foils in both the one-sided and double-sided laser-interaction configuration is presented. Spectrally-integrated framing camera images show intensity contributions of front and rear backlighter surfaces for both foil types. Analysis of time-resolved x-ray spectra… more
Date: June 5, 2000
Creator: Bullock, A. B.; Landen, O. L. & Bradley, D. K.
Partner: UNT Libraries Government Documents Department
open access

Relative stability of silicon self-interstitial defects

Description: {l_brace}311{r_brace} defects and dislocation loops are formed after ion-implantation and annealing of a silicon wafer. Recent Transmission Electron Microscopy studies by Li and Jones have shown that sub-threshold dislocation loops nucleate from {l_brace}311{r_brace} defects. In our study, the conjugate gradient method with the Stillinger Weber potential is used to relax different configurations such as {l_brace}311{r_brace} defects with a maximum of five chains and perfect dislocation loops. F… more
Date: April 11, 2000
Creator: Subramanian, G; Jones, K S; Law, M E; Caturla, M J; Theiss, S & Diaz de la Rubia, T
Partner: UNT Libraries Government Documents Department
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