69 Matching Results

Search Results

Results: 1 - 24 next
open access

Going with the flow: Life cycle costing for industrial pumping systems

Description: Industries worldwide depend upon pumping systems for theirdaily operation. These systems account for nearly 20 percent of theworld's industrial electrical energy demand and range from 25-50 percentof the energy usage in certain industrial plant operations. Purchasedecisions for a pump and its related system components are typicallybased upon a low bid, rather than the cost to operate the system over itslifetime. Additionally, plant facilities personnel are typically focussedon maintaining exist… more
Date: July 8, 2002
Creator: Tutterow, Vestal; Hovstadius, Gunnar & McKane, Aimee
Partner: UNT Libraries Government Documents Department
open access

Field and Current Amplification in the SSPX Spheromak

Description: Results are presented from experiments relating to magnetic field generation and current amplification in the SSPX spheromak. The SSPX spheromak plasma is driven by DC coaxial helicity injection using a 2MJ capacitor bank. Peak toroidal plasma currents of up to 0.7MA and peak edge poloidal fields of 0.3T are produced; lower current discharges can be sustained up to 3.5msec. When edge magnetic fluctuations are reduced below 1% by driving the plasma near threshold, it is possible to produce plasm… more
Date: October 8, 2002
Creator: Hill, D. N.; Blumer, R. H.; Cohen, B. I.; Hooper, E. B.; McLean, H. S.; Moller, J. et al.
Partner: UNT Libraries Government Documents Department
open access

Recent Advances in Indirect Drive ICF Target Physics

Description: In preparation for ignition on the National Ignition Facility, the Lawrence Livermore National Laboratory's Inertial Confinement Fusion Program, working in collaboration with Los Alamos National Laboratory, Commissariat a lEnergie Atomique (CEA), and Laboratory for Laser Energetics at the University of Rochester, has performed a broad range of experiments on the Nova and Omega lasers to test the fundamentals of the NIF target designs. These studies have refined our understanding of the importan… more
Date: October 8, 2002
Creator: Hammel, B.; Lindl, J.; Amendt, P. A.; Bernat, G. W.; Collins, G. W.; Glenzer, S. H. et al.
Partner: UNT Libraries Government Documents Department
open access

Classification of Bent-Double Galaxies: Experiences with Ensembles of Decision Trees

Description: In earlier work, we have described our experiences with the use of decision tree classifiers to identify radio-emitting galaxies with a bent-double morphology in the FIRST astronomical survey. We now extend this work to include ensembles of decision tree classifiers, including two algorithms developed by us. These algorithms randomize the decision at each node of the tree, and because they consider fewer candidate splitting points, are faster than other methods for creating ensembles. The exper… more
Date: January 8, 2002
Creator: Kamath, C & Cantu-Paz, E
Partner: UNT Libraries Government Documents Department
open access

Chemistry at Extreme Conditions

Description: We present equation of state results from impulsively stimulated light scattering (ISLS) experiments conducted in diamond anvil cells on pure supercritical fluids. We have made measurements on fluid H{sub 2}O (water), and CH{sub 3}OH (methanol). Sound speeds measured through ISLS have allowed us to refine existing potential models used in the exponential-6 (EXP-6) detonation product library [Fried, L. E., and Howard, W. M., J. Chem. Phys. 109 (17): 7338-7348 (1998).]. The refined models allow u… more
Date: August 8, 2002
Creator: Zaug, J M; Fried, L E; Abramson, E H; Hansen, D W; Crowhurst, J C & Howard, W M
Partner: UNT Libraries Government Documents Department
open access

The Ags High Power Upgrade Plan.

Description: BNL could provide a Megawatt class neutrino beam from the AGS for very long baseline neutrino experiments. We have studied two possible approaches to upgrade the AGS to 1.0 MW beam power. The first is the linac option, comprising a new superconducting linac injector of 1.2 GeV, accelerating 9 x 10{sup 3} proton per pulse in the AGS to 28 GeV at 2.5 Hz. The second option is to extend the existing 200 MeV linac to 400 MeV. ramp the Booster to 2.5 GeV at 6 Hz. add a new 2.5 GeV accumulator ring in… more
Date: April 8, 2002
Creator: Weng, W. T. & Roser, T.
Partner: UNT Libraries Government Documents Department
open access

Magnetic gradiometer based on a high-transition temperature superconducting quantum interference device for improved sensitivity of abiosensor

Description: We describe a gradiometer based on a high-transition temperature Superconducting Quantum Interference Device (SQUID) for improving the sensitivity of a SQUID-based biosensor. The first-derivative gradiometer, fabricated from a single layer of YBa{sub 2}Cu{sub 3}O{sub 7-x}, has a baseline of 480 {micro}m and a balance against uniform fields of 1 part in 150. Used in our SQUID ''microscope,'' it reduces parasitic magnetic fields generated by the measurement process to the level of the SQUID noise… more
Date: July 8, 2002
Creator: Lee, Seung Kyun; Myers, W. R.; Grossman, H. L.; Cho, H.-M.; Chemla,Y. R. & Clarke, John
Partner: UNT Libraries Government Documents Department
open access

Electron cloud development in the Proton Storage Ring and in theSpallation Neutron Source

Description: We have applied our simulation code "POSINST" to evaluatethe contribution to the growth rate of the electron-cloud instability inproton storage rings. Recent simulation results for the main features ofthe electron cloud in the storage ring of the Spallation Neutron Source(SNS) at Oak Ridge, and updated results for the Proton Storage Ring (PSR)at Los Alamos are presented in this paper. A key ingredient in our modelis a detailed description of the secondary emitted-electron energyspectrum. A refi… more
Date: October 8, 2002
Creator: Pivi, M. T. F. & Furman, M. A.
Partner: UNT Libraries Government Documents Department
open access

Strong-strong beam-beam simulation using a green function approach

Description: In this paper we present a news approach, based on a shifted Green function, to evaluate the electromagnetic field in a simulation of colliding beams. Unlike a conventional particle-mesh code, we use a method in which the computational mesh covers only the largest of the two colliding beams. This allows us to study long-range parasitic collisions accurately and efficiently. We have implemented this algorithm in a new parallel strong-strong beam-beam simulation code. As an application, we presen… more
Date: September 8, 2002
Creator: Qiang, Ji; Furman, Miguel A. & Ryne, Robert D.
Partner: UNT Libraries Government Documents Department
open access

Design and Testing of Improved Spacesuit Shielding Components

Description: In prior studies of the current Shuttle Spacesuit (SSA), where basic fabric lay-ups were tested for shielding capabilities, it was found that the fabric portions of the suit give far less protection than previously estimated due to porosity and non-uniformity of fabric and LCVG components. In addition, overall material transmission properties were less than optimum. A number of alternate approaches are being tested to provide more uniform coverage and to use more efficient materials. We will di… more
Date: May 8, 2002
Creator: Ware, J.; Ferl, J.; Wilson, J.W.; Clowdsley, M.S.; DeAngelis, G.; Tweed, J. et al.
Partner: UNT Libraries Government Documents Department
open access

Studies of N{sub 2}0 adsorption and decomposition on Fe-ZSM-5

Description: The interactions of N2O with H-ZSM-5 and Fe-ZSM-5 have been investigated using infrared spectroscopy and temperature-programmed reaction. Fe-ZSM-5 samples with Fe/Al ratios of 0.17 and 0.33 were prepared by solid-state exchange. It was determined that most of the iron in the samples of Fe-ZSM-5 is in the form of isolated cations, which have exchanged with Bronsted acid H+ in H-ZSM-5. The infrared spectrum of N2O adsorbed on H-ZSM-5 at 298 K exhibits bands at 2226 and 1308 cm-1 associated with v… more
Date: March 8, 2002
Creator: Wood, Benjamin R.; Reimer, Jeffrey A. & Bell, Alexis T.
Partner: UNT Libraries Government Documents Department
open access

Surface preparation and characterization of the icosahedral Al-Pd-Mn-Ga quasicrystal

Description: Auger electron spectroscopy and low-energy electron diffraction (LEED) provide basic information about the structure and composition of the fivefold surface of the quaternary quasicrystal, icosahedral Al67Pd4Mn21Ga8. Surface preparation techniques established previously for two of the icosahedral ternary alloys, Al-Pd-Mn and Al-Cu-Fe, appear to be similarly effective for Al-Pd-Mn-Ga. After annealing in the range 600-950 K, the surface concentration of Ga is constant and low. After annealing in … more
Date: January 8, 2002
Creator: Heinzig, Mark; Jenks, Cynthia J.; Van Hove, Michel; Fisher, Ian; Canfield, Paul & Thiel, Patricia A.
Partner: UNT Libraries Government Documents Department
open access

NdFeB magnets aligned in a 9-T superconducting solenoid.

Description: Commercial-grade magnet powder (Magnequench UG) was uniaxial die-pressed into cylindrical compacts, while being aligned in the 1-T to 8-T DC field of a superconducting solenoid at Argonne National Laboratory. Then, the compacts were added to normal Magnequench UG production batches for sintering and annealing. The variations in magnet properties for different strengths of alignment fields are reported for 15.88-mm (5/8-in.) diameter compacts made with length-to-diameter (L/D) ratios in the rang… more
Date: May 8, 2002
Creator: Mulcahy, T. M.; Hull, J. R.; Rozendaal, E. & Wise, J. H.
Partner: UNT Libraries Government Documents Department
open access

Nondestructive evaluation of ceramic matrix composite combustor components.

Description: Combustor liners fabricated from a SiC/SiC composite were nondestructively interrogated before and after combustion rig testing. The combustor liners were inspected by X-ray, ultrasonic and thermographic techniques. In addition, mechanical test results were obtained from witness coupons, representing the as-manufactured liners, and from coupons machined from the components after combustion exposure. Thermography indications were found to correlate with reduced material properties obtained after… more
Date: November 8, 2002
Creator: Sun, J. G.; Verrilli, M. J.; Stephan, R.; Barnett, T. R. & Ojard, G.
Partner: UNT Libraries Government Documents Department
open access

Application of automatic differentiation for the simulation of nonisothermal, multiphase flow in geothermal reservoirs

Description: Simulation of nonisothermal, multiphase flow through fractured geothermal reservoirs involves the solution of a system of strongly nonlinear algebraic equations. The Newton-Raphson method used to solve such a nonlinear system of equations requires the evaluation of a Jacobian matrix. In this paper we discuss automatic differentiation (AD) as a method for analytically computing the Jacobian matrix of derivatives. Robustness and efficiency of the AD-generated derivative codes are compared with a … more
Date: January 8, 2002
Creator: Kim, Jong G. & Finsterle, Stefan
Partner: UNT Libraries Government Documents Department
open access

Demonstration of the Robotic Gamma Locating and Isotopic Identification Device

Description: The United States Department of Energy (DOE) continually seeks safer and more cost-effective technologies for use in decontaminating and decommissioning nuclear facilities. To this end, the Deactivation and Decommissioning Focus Area of DOE's Office of Science and Technology sponsors Large-Scale Demonstration and Deployment Projects (LSDDP) to test new technologies. As part of these projects, developers and vendors showcase new products designed to decrease health and safety risks to personnel … more
Date: May 8, 2002
Creator: Anderson, M. O.; Conner, C. C.; Daniel, V. E.; McKay, M. D. & Yancey, N. A.
Partner: UNT Libraries Government Documents Department
open access

Experiments and Modeling of High Altitude Chemical Agent Release

Description: Using ASCA data, we find, contrary to other researchers using ROSAT data, that the X-ray spectra of the VY Scl stars TT Ari and KR Aur are poorly fit by an absorbed blackbody model but are well fit by an absorbed thermal plasma model. The different conclusions about the nature of the X-ray spectrum of KR Aur may be due to differences in the accretion rate, since this Star was in a high optical state during the ROSAT observation, but in an intermediate optical state during the ASCA observation. … more
Date: July 8, 2002
Creator: Nakafuji, G.; Greenman, R. & Theofanous, T.
Partner: UNT Libraries Government Documents Department
open access

Aluminosilicate Formation in High Level Waste Evaporators: A Mechanism for Uranium Accumulation

Description: High level waste Evaporators at the Savannah River Site (SRS) process radioactive waste to concentrate supernate and thus conserve tank space. In June of 1997, difficulty in evaporator operation was initially observed. This operational difficulty evidenced itself as a plugging of the evaporator's gravity drain line (GDL). The material blocking the GDL was determined to be a sodium aluminosilicate. Following a mechanical cleaning of the GDL, the evaporator was returned to service until October 1… more
Date: February 8, 2002
Creator: Wilmarth, W. R.
Partner: UNT Libraries Government Documents Department
open access

Orbit: A Code for Collective Beam Dynamics in High Intensity Rings.

Description: We are developing a computer code, ORBIT, specifically for beam dynamics calculations in high-intensity rings. Our approach allows detailed simulation of realistic accelerator problems. ORBIT is a particle-in-cell tracking code that transports bunches of interacting particles through a series of nodes representing elements, effects, or diagnostics that occur in the accelerator lattice. At present, ORBIT contains detailed models for strip-foil injection, including painting and foil scattering; r… more
Date: April 8, 2002
Creator: Holmes, J. A.; Danilov, V.; Galambos, J.; Shishlo, A.; Cousineau, S.; Chou, W. et al.
Partner: UNT Libraries Government Documents Department
open access

Longitudinal Dynamics in High Frequency FFAG Recirculating Accelerators.

Description: A recirculating accelerator accelerates the beam by passing through accelerating cavities multiple times. An FFAG recirculating accelerator uses a single arc to connect the linacs together, as opposed to multiple arcs for the different energies. For most scenarios using high-frequency RF, it is impractical to change the phase of the RF on each pass, at least for lower energy accelerators. Ideally, therefore, the WAG arc will be isochronous, so that the particles come back to the same phase (on-… more
Date: April 8, 2002
Creator: Berg, J. S.
Partner: UNT Libraries Government Documents Department
Back to Top of Screen