Sample records for duct high velocity

  1. LDV measurements of the velocity field within a ribbed internal duct flow

    SciTech Connect (OSTI)

    Huckle, E.; Pantelic, D.; Hu, K.; Jones, S.; Travkin, V.; Catton, I.

    1999-07-01T23:59:59.000Z

    Laser Doppler velocimetry (LDV) has been used to measure the velocity field in an internal duct flow of air with regular rib roughness. The experiments were conducted to study the effect regular wall obstacles have on the flow velocity field. The instantaneous u and v velocities were measured in both a smooth and rough rectangular duct. For the smooth channel the wind tunnel Reynolds number capability was first investigated and was shown to be linear with blower shaft frequency, having a range of 13,000--42,000. Next, the turbulent velocity profiles were measured in the smooth channel for 6 different blower speeds (Reynolds numbers), and the results greatly resembled those found in previous literature. Twenty sets of rectangular, 6.35 mm x 6.35 mm ribs were then mounted to the top and bottom of the channel with a spacing of 75 mm (P/H = 11.8). A grid of nodes were selected and the turbulent velocities were measured for a given Reynolds number, and are presented and discussed. Valuable insight was gained which will aid in future studies intended to measure the Reynolds stress and other closure terms.

  2. Theoretical Estimates of HVAC Duct Channel Capacity for High-Speed Internet Access

    E-Print Network [OSTI]

    Stancil, Daniel D.

    Theoretical Estimates of HVAC Duct Channel Capacity for High-Speed Internet Access Ariton E. Xhafa-conditioning (HVAC) ducts based on multi-carrier transmission that uses M-QAM mod- ulation and measured channel- flections in HVAC ducts). Our work also shows that data rates in excess of 300 Mbps are possible over

  3. An Experimental Method for Determining the Time Constants of Capacitive Thin-Film Polymer Humidity sensors at Various Duct Air Velocities

    E-Print Network [OSTI]

    Dooley, B.; O'Neal, D.

    outputs in response to step changes in RH and temperature over a range of air velocities. Duct air velocities ofO (stili air). 200. 500. 800, and UOOft/min (0. 1.0, 2.5. 4.1, and 5.6 m/s) were considered along with .step changes in RH of 20%-40% and step.... The duct air velocity was measured with two identical thermal anemometer probes, one in each duct. The anemometers were calibrated with a pitot-static pressure measurement in a low-speed wind tunnel. A secondary cheek was performed by measuring the air...

  4. High-velocity clouds: a diverse phenomenon

    E-Print Network [OSTI]

    B. P. Wakker

    2001-09-13T23:59:59.000Z

    In this contribution the current state of knowledge about the high-velocity clouds (HVCs) is summarized. Recent progress has shown that the HVCs are a diverse phenomenon. The intermediate-velocity clouds (IVCs) are likely to be part of a Galactic Fountain. The Magellanic Stream is a tidal remnant. HVC complex C (possibly complexes A and GCN) are low-metallicity clouds near the Galaxy; they could be remnants of the formation of the Galaxy or old tidal streams extracted from nearby dwarf galaxies. Having a substantial number of HI HVCs dispersed throughout the Local Group seems incompatible with the observed HI mass function of galaxies. Finally, FUSE finds high-velocity OVI, some of which is clearly associated with HI HVCs, but some which is not.

  5. Particle deposition in ventilation ducts: Connectors, bends anddeveloping flow

    SciTech Connect (OSTI)

    Sippola, Mark R.; Nazaroff, William W.

    2004-03-01T23:59:59.000Z

    In ventilation duct flow the turbulent flow profile is commonly disturbed or not fully developed and these conditions are likely to influence particle deposition to duct surfaces. Particle deposition rates at eight S-connectors, in two 90{sup o} duct bends and in two ducts where the turbulent flow profile was not fully developed were measured in a laboratory duct system with both galvanized steel and internally insulated ducts with hydraulic diameters of 15.2 cm. In the steel duct system, experiments with nominal particle diameters of 1, 3, 5, 9 and 16 {micro}m were conducted at each of three nominal air speeds: 2.2, 5.3 and 9.0 m/s. In the insulated duct system, deposition of particles with nominal diameters of 1, 3, 5, 8 and 13 {micro}m was measured at nominal air speeds of 2.2, 5.3 and 8.8 m/s. Fluorescent techniques were used to directly measure the deposition velocities of monodisperse fluorescent particles to duct surfaces. Deposition at S-connectors, in bends and in straight ducts with developing turbulence was often greater than deposition in straight ducts with fully developed turbulence for equal particle sizes, air speeds and duct surface orientations. Deposition rates at all locations were found to increase with an increase in particle size or air speed. High deposition rates at S-connectors resulted from impaction and these rates were nearly independent of the orientation of the S-connector. Deposition rates in the two 90{sup o} bends differed by more than an order of magnitude in some cases, probably because of the difference in turbulence conditions at the bend inlets. In straight steel ducts where the turbulent flow profile was developing, the deposition enhancement relative to fully developed turbulence generally increased with air speed and decreased with downstream distance from the duct inlet. This enhancement was greater at the duct ceiling and wall than at the duct floor. In insulated ducts, deposition enhancement was less pronounced overall than in steel ducts. Trends that were observed in steel ducts were present, but weaker, in insulated ducts.

  6. Lensing duct

    DOE Patents [OSTI]

    Beach, R.J.; Benett, W.J.

    1994-04-26T23:59:59.000Z

    A lensing duct to condense (intensify) light using a combination of front surface lensing and reflective waveguiding is described. The duct tapers down from a wide input side to a narrow output side, with the input side being lens-shaped and coated with an antireflective coating for more efficient transmission into the duct. The four side surfaces are uncoated, preventing light from escaping by total internal reflection as it travels along the duct (reflective waveguiding). The duct has various applications for intensifying light, such as in the coupling of diode array pump light to solid state lasing materials, and can be fabricated from inexpensive glass and plastic. 3 figures.

  7. Computer Aided Duct Design

    E-Print Network [OSTI]

    Clark, W. H.

    1994-01-01T23:59:59.000Z

    simple Cartesian coordinate system with velocity and static pressure as the axes. A userdefined target curve is plotted on this background and each segment of the duct is plotted on the graph to permit a close approximation to the ideal, which is a...

  8. High-Speed Internet Access via HVAC Ducts: A New Approach Daniel D. Stancil, Ozan K. Tonguz, Ariton Xhafa, Ahmet Cepni, and Pavel Nikitin

    E-Print Network [OSTI]

    Stancil, Daniel D.

    High-Speed Internet Access via HVAC Ducts: A New Approach Daniel D. Stancil, Ozan K. Tonguz, Ariton conditioning (HVAC) ducts for indoor wireless transmission systems and networks. Mea- surements and system to 100 Mbps should be possible, when HVAC system is used in con- junction with OFDM technology. Keywords

  9. Compact, Isolated High-Velocity Clouds

    E-Print Network [OSTI]

    W. B. Burton; R. Braun; V. de Heij

    2002-06-20T23:59:59.000Z

    We consider here the class of compact, isolated, high-velocity HI clouds, CHVCs, which are sharply bounded in angular extent down to a limiting column density of 1.5x10^18 cm^-2. We describe our automated search algorithm and it's application to the LDS north of dec= -28 deg. and the HIPASS data south of dec=0, resulting in an all--sky catalog numbering 246 CHVCs. We argue that these objects are more likely to represent a single phenomenon in a similar evolutionary state than would a sample which included any of the major HVC complexes. Five principal observables are defined for the CHVC population: (1) the spatial deployment of the objects on the sky, (2) the kinematic distribution, (3) the number distribution of observed HI column densities, (4) the number distribution of angular sizes, and (5) the number distribution of line widths. We show that the spatial and kinematic deployments of the ensemble of CHVCs contain various clues regarding their characteristic distance. These clues are not compatible with a location of the ensemble within the Galaxy proper. The deployments resemble in several regards those of the Local Group galaxies. We describe a model testing the hypothesis that the CHVCs are a Local Group population. The agreement of the model with the data is judged by extracting the observables from simulations, in a manner consistent with the sensitivities of the observations and explicitly taking account of Galactic obscuration. We show that models in which the CHVCs are the HI counterparts of dark-matter halos evolving in the Local Group potential provide a good match to the observables, if account is taken of tidal and ram--pressure disruption, the consequences of obscuration due to Galactic HI and of differing sensitivities and selection effects pertaining to the surveys.

  10. Cryogenic Testing of High-Velocity Spoke Cavities

    SciTech Connect (OSTI)

    Hopper, Christopher S. [Old Dominion University; Delayen, Jean R. [Old Dominion University; Park, HyeKyoung [JLAB

    2014-12-01T23:59:59.000Z

    Spoke-loaded cavities are being investigated for the high-velocity regime. The relative compactness at low-frequency makes them attractive for applications requiring, or benefiting from, 4 K operation. Additionally, the large velocity acceptance makes them good candidates for the acceleration of high-velocity protons and ions. Here we present the results of cryogenic testing of a 325 MHz, ?0= 0.82 single-spoke cavity and a 500 MHz, ?0 = 1 double-spoke cavity.

  11. High-resolution imaging of compact high-velocity clouds

    E-Print Network [OSTI]

    Robert Braun; Butler Burton

    1999-12-20T23:59:59.000Z

    Six examples of the compact, isolated high-velocity HI clouds (CHVCs) identified by Braun and Burton (1999) have been imaged with the WSRT. The 65 confirmed objects in this class define a dynamically cold system, with a global minimum for the velocity dispersion of only 70 km/s, found in the Local Group Standard of Rest, while in-falling at 100 km/s toward the LG barycenter. These objects have a characteristic morphology, in which several compact cores are embedded in a diffuse halo. The compact cores typically account for 40% of the HI line flux while covering some 15% of the source area. The cores are the cool condensed phase of HI, the CNM, with temp. near 100 K, while the halos appear to be a shielding column of warm diffuse HI, the WNM, with temp. near 8000 K. We detect a core with one of the narrowest HI emission lines ever observed, with intrinsic FWHM of 2 km/s and 75 K brightness. From a comparison of column and volume densities we derive a distance in the range 0.5 to 1 Mpc. We determine a metallicity for this same object of 0.04 to 0.07 solar. Comparably high distances are implied by demanding the stability of objects with multiple cores, which show relative velocities as large as 70 km/s on 30 arcmin scales. Many compact cores show systematic velocity gradients along the major axis of their elliptical extent which are consistent with circular rotation. Several of the derived rotation curves are well-fit by Navarro, Frenk, and White (1997) cold dark matter profiles. These kinematic signatures imply a high dark-to-visible mass ratio of 10-50, for D=0.7Mpc, which scales as 1/D. The implied dark matter halos dominate the mass volume density within the central 2 kpc (10 arcmin) of each source, providing a sufficent hydrostatic pressure to allow local CNM condensation. (abridged)

  12. Compact High-Velocity Clouds at High Resolution

    E-Print Network [OSTI]

    W. B. Burton; Robert Braun

    1999-12-22T23:59:59.000Z

    Six examples of the compact, isolated high-velocity clouds catalogued by Braun & Burton (1999) and identified with a dynamically cold ensemble of primitive objects falling towards the barycenter of the Local Group have been imaged with the Westerbork Synthesis Radio Telescope; an additional ten have been imaged with the Arecibo telescope. The imaging reveals a characteristic core/halo morphology: one or several cores of cool, relatively high-column-density material, are embedded in an extended halo of warmer, lower-density material. Several of the cores show kinematic gradients consistent with rotation; these CHVCs are evidently rotationally supported and dark-matter dominated. The imaging data allows several independent estimates of the distances to these objects, which lie in the range 0.3 to 1.0 Mpc. The CHVC properties resemble what might be expected from very dark dwarf irregular galaxies.

  13. Superconducting spoke cavities for high-velocity applications

    SciTech Connect (OSTI)

    Hopper, Christopher S. [Old Dominion U.; Delayen, Jean R. [Old Dominion U., JLAB

    2013-10-01T23:59:59.000Z

    To date, superconducting spoke cavities have been designed, developed, and tested for particle velocities up to {beta}{sub 0}~0.6, but there is a growing interest in possible applications of multispoke cavities for high-velocity applications. We have explored the design parameter space for low-frequency, high-velocity, double-spoke superconducting cavities in order to determine how each design parameter affects the electromagnetic properties, in particular the surface electromagnetic fields and the shunt impedance. We present detailed design for cavities operating at 325 and 352 MHz and optimized for {beta}{sub 0}~=0.82 and 1.

  14. Modeling and Control of High-Velocity Oxygen-Fuel (HVOF) Thermal Spray: A Tutorial Review

    E-Print Network [OSTI]

    Li, Mingheng; Christofides, Panagiotis D.

    2009-01-01T23:59:59.000Z

    Fluid Dynamics Analysis of a Wire- Feed, High-Velocity Oxygen Fuel (Fluid Dynamic Modeling of Gas Flow Charac- teristics in a High-Velocity Oxy-Fuel

  15. High velocity compact clouds in the sagittarius C region

    SciTech Connect (OSTI)

    Tanaka, Kunihiko; Oka, Tomoharu; Matsumura, Shinji [Department of Physics, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Yokohama, Kanagawa 223-8522 (Japan); Nagai, Makoto [Division of Physics, Faculty of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Ten-noudai, Tsukuba, Ibaraki 305-8571 (Japan); Kamegai, Kazuhisa, E-mail: ktanaka@phys.keio.ac.jp [Department of Industrial Administration, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan)

    2014-03-01T23:59:59.000Z

    We report the detection of extremely broad emission toward two molecular clumps in the Galactic central molecular zone. We have mapped the Sagittarius C complex (–0.°61 < l < –0.°27, –0.°29 < b < 0.°04) in the HCN J = 4-3, {sup 13}CO J = 3-2, and H{sup 13}CN J = 1-0 lines with the ASTE 10 m and NRO 45 m telescopes, detecting bright emission with 80-120 km s{sup –1} velocity width (in full-width at zero intensity) toward CO–0.30–0.07 and CO–0.40–0.22, which are high velocity compact clouds (HVCCs) identified with our previous CO J = 3-2 survey. Our data reveal an interesting internal structure of CO–0.30–0.07 comprising a pair of high velocity lobes. The spatial-velocity structure of CO–0.40–0.22 can be also understood as a multiple velocity component, or a velocity gradient across the cloud. They are both located on the rims of two molecular shells of about 10 pc in radius. Kinetic energies of CO–0.30–0.07 and CO–0.40–0.22 are (0.8-2) × 10{sup 49} erg and (1-4) × 10{sup 49} erg, respectively. We propose several interpretations of their broad emission: collision between clouds associated with the shells, bipolar outflow, expansion driven by supernovae (SNe), and rotation around a dark massive object. These scenarios cannot be discriminated because of the insufficient angular resolution of our data, though the absence of a visible energy source associated with the HVCCs seems to favor the cloud-cloud collision scenario. Kinetic energies of the two molecular shells are 1 × 10{sup 51} erg and 0.7 × 10{sup 51} erg, which can be furnished by multiple SN or hypernova explosions in 2 × 10{sup 5} yr. These shells are candidates of molecular superbubbles created after past active star formation.

  16. Velocity distribution of high-energy particles and the solar neutrino problem

    E-Print Network [OSTI]

    Jian-Miin Liu

    2001-08-18T23:59:59.000Z

    High energy infers high velocity and high velocity is a concept of special relativity. The Maxwellian velocity distribution is corrected to be consistent with special relativity. The corrected distribution reduces to the Maxwellian distribution for small velocities, contains a relatively depleted high-energy tail and vanishes at the velocity of light. This corrected distribution will lower solar neutrino fluxes and change solar neutrino energy spectra but keep solar sound speeds.

  17. Duct joining system

    DOE Patents [OSTI]

    Proctor, John P. (44 Glen Dr., Fairfax, CA 94930); deKieffer, Robert C. (Boulder, CO)

    2001-01-01T23:59:59.000Z

    A duct joining system for providing an air-tight seal and mechanical connection for ducts and fittings is disclosed. The duct joining system includes a flexible gasket affixed to a male end of a duct or fitting. The flexible gasket is affixed at an angle relative to normal of the male end of the duct. The female end of the other duct includes a raised bead in which the flexible gasket is seated when the ducts are properly joined. The angled flexible gasket seated in the raised bead forms an air-tight seal as well as fastens or locks the male end to the female end. Alternatively, when a flexible duct is used, a band clamp with a raised bead is clamped over the female end of the flexible duct and over the male end of a fitting to provide an air tight seal and fastened connection.

  18. Duct Joining System

    DOE Patents [OSTI]

    Proctor, John P. (Fairfax, CA)

    2001-02-27T23:59:59.000Z

    A duct joining system for providing an air-tight seal and mechanical connection for ducts and fittings is disclosed. The duct joining system includes a flexible gasket affixed to a male end of a duct or fitting. The flexible gasket is affixed at an angle relative to normal of the male end of the duct. The female end of the other duct includes a raised bead in which the flexible gasket is seated when the ducts are properly joined. The angled flexible gasket seated in the raised bead forms an air-tight seal as well as fastens or locks the male end to the female end. Alternatively, when a flexible duct is used, a band clamp with a raised bead is clamped over the female end of the flexible duct and over the male end of a fitting to provide an air tight seal and fastened connection.

  19. STATE OF CALIFORNIA DUCT LEAKAGE TEST EXISTING DUCT SYSTEM

    E-Print Network [OSTI]

    ) ventilation systems, shall not be sealed/taped off during duct leakage testing. CFI OA ducts that utilize

  20. Arecibo imaging of compact high-velocity clouds

    E-Print Network [OSTI]

    Burton, W B; Chengalur, J N

    2001-01-01T23:59:59.000Z

    Ten isolated compact high-velocity clouds (CHVCs) of the type cataloged by Braun & Burton (1999) have been imaged with the Arecibo telescope and were found to have a nested core/halo morphology. We argue that a combination of high-resolution filled-aperture and synthesis data is crucial to determining the intrinsic properties of the CHVCs. We identify the halos as Warm Neutral Medium surrounding one or more cores in the Cool Neutral Medium phase. These halos are clearly detected and resolved by the Arecibo filled-aperture imaging, which reaches a limiting sensitivity (1 sigma) of N_H about 2x10^17 cm^-2 over the typical 70 km/s linewidth at zero intensity. The FWHM linewidth of the halo gas is found to be 25 km/s, consistent with a WNM thermal broadening within 10^4 K gas. Substantial asymmetries are found at high N_H (>10^18.5 cm^-2) levels in 60% of our sample. A high degree of reflection-symmetry is found at low N_H (<10^18.5 cm^-2) in all sources studied at these levels. The column-density profiles...

  1. Introduction The Smith Cloud is a high velocity cloud with a radial velocity near

    E-Print Network [OSTI]

    Wisconsin at Madison, University of

    .8 ­ 15.1 kpc (Wakker et al. 2008). Lockman et al. (2008) presented an H I survey of the cloud using the off and on spectra of each line to a single atmospheric template, which we then subtracted from velocities, Figure 2 shows ON­OFF spectra with no atmospheric template for this line. Like Bland-Hawthorn et

  2. Arecibo imaging of compact high-velocity clouds

    E-Print Network [OSTI]

    W. B. Burton; R. Braun; J. N. Chengalur

    2001-02-06T23:59:59.000Z

    Ten isolated compact high-velocity clouds (CHVCs) of the type cataloged by Braun & Burton (1999) have been imaged with the Arecibo telescope and were found to have a nested core/halo morphology. We argue that a combination of high-resolution filled-aperture and synthesis data is crucial to determining the intrinsic properties of the CHVCs. We identify the halos as Warm Neutral Medium surrounding one or more cores in the Cool Neutral Medium phase. These halos are clearly detected and resolved by the Arecibo filled-aperture imaging, which reaches a limiting sensitivity (1 sigma) of N_H about 2x10^17 cm^-2 over the typical 70 km/s linewidth at zero intensity. The FWHM linewidth of the halo gas is found to be 25 km/s, consistent with a WNM thermal broadening within 10^4 K gas. Substantial asymmetries are found at high N_H (>10^18.5 cm^-2) levels in 60% of our sample. A high degree of reflection-symmetry is found at low N_H (<10^18.5 cm^-2) in all sources studied at these levels. The column-density profiles of the envelopes are described well by the sky-plane projection of a spherical exponential in atomic volume density, which allows estimating the characteristic central halo column density, N_H(0) = 4.1+/-3.2x10^19 cm^-2, and characteristic exponential scale-length, h_B=420+/-90 arcsec. For plausible values of the thermal pressure at the CNM/WNM interface, these edge profiles allow distance estimates to be made for the individual CHVCs studied here which range between 150 and 850 kpc. (abridged)

  3. Measurement of fluid-flow-velocity profile in turbid media by the use of optical Doppler tomography

    SciTech Connect (OSTI)

    Wang, Xiao-Jun; Milner, T.E.; Chen, Zhongping; Nelson, J.S. [Beckman Laser Institute and Medical Clinic, University of California-Irvine, Irvine, California 92715 (United States)]|[Department of Physics, Georgia Southern University, Statesboro, Georgia 30460 (United States)

    1997-01-01T23:59:59.000Z

    Optical Doppler tomography is demonstrated to be a simple, accurate, and noncontact method for measuring the fluid velocity of laminar flow in small-diameter ({approximately}0.5-mm) ducts. Studies are described that utilize circular (square) plastic (glass) ducts infused with a moving suspension of polymer micro-spheres in air and buried in an optically turbid medium. The measurement of Doppler-shifted frequencies of backscattered light from moving microspheres is used to construct a high-resolution spatial profile of fluid-flow velocity in the ducts. {copyright} 1997 Optical Society of America

  4. Distances and Metallicities of High- and Intermediate-Velocity Clouds

    E-Print Network [OSTI]

    B. P. Wakker

    2001-02-08T23:59:59.000Z

    A table is presented that summarizes published absorption line measurements for the high- and intermediate velocity clouds (HVCs and IVCs). New values are derived for N(HI) in the direction of observed probes, in order to arrive at reliable abundances and abundance limits (the HI data are described in Paper II). Distances to stellar probes are revisited and calculated consistently, in order to derive distance brackets or limits for many of the clouds, taking care to properly interpret non-detections. The main conclusions are the following. 1) Absolute abundances have been measured using lines of SII, NI and OI, with the following resulting values: ~0.1 solar for one HVC (complex C), ~0.3 solar for the Magellanic Stream, ~0.5 solar for a southern IVC, and ~ solar for two northern IVCs (the IV Arch and LLIV Arch). Finally, approximate values in the range 0.5-2 solar are found for three more IVCs. 2) Depletion patterns in IVCs are like those in warm disk or halo gas. 3) Most distance limits are based on strong UV lines of CII, SiII and MgII, a few on CaII. Distance limits for major HVCs are >5 kpc, while distance brackets for several IVCs are in the range 0.5-2 kpc. 4) Mass limits for major IVCs are 0.5-8x10^5 M_sun, but for major HVCs they are >10^6 M_sun. 5) The CaII/HI ratio varies by up to a factor 2-5 within a single cloud, somewhat more between clouds. 6) The NaIHI ratio varies by a factor >10 within a cloud, and even more between clouds. Thus, CaII can be useful for determining both lower and upper distance limits, but NaI only yields upper limits.

  5. High- and low-temperature-stable thermite composition for producing high-pressure, high-velocity gases

    DOE Patents [OSTI]

    Halcomb, Danny L. (Camden, OH); Mohler, Jonathan H. (Spring Valley, OH)

    1990-10-16T23:59:59.000Z

    A high- and low-temperature-stable thermite composition for producing high-pressure and high-velocity gases comprises an oxidizable metal, an oxidizing reagent, and a high-temperature-stable gas-producing additive selected from the group consisting of metal carbides and metal nitrides.

  6. Duct Tape Durability Testing

    SciTech Connect (OSTI)

    Sherman, Max H.; Walker, Iain S.

    2004-04-01T23:59:59.000Z

    Duct leakage is a major source of energy loss in residential buildings. Most duct leakage occurs at the connections to registers, plenums, or branches in the duct system. At each of these connections, a method of sealing the duct system is required. Typical sealing methods include tapes or mastics applied around the joints in the system. Field examinations of duct systems have shown that taped seals tend to fail over extended periods of time. The Lawrence Berkeley National Laboratory (LBNL) has been testing sealant durability for several years using accelerated test methods and found that typical duct tape (i.e., cloth-backed tapes with natural rubber adhesives) fails more rapidly than other duct sealants. This report summarizes the results of duct sealant durability testing over two years for four UL 181B-FX listed duct tapes (two cloth tapes, a foil tape and an Oriented Polypropylene (OPP) tape). One of the cloth tapes was specifically developed in collaboration with a tape manufacturer to perform better in our durability testing. The tests involved the aging of common ''core-to-collar joints'' of flexible duct to sheet metal collars. Periodic air leakage tests and visual inspection were used to document changes in sealant performance. After two years of testing, the flex-to-collar connections showed little change in air leakage, but substantial visual degradation from some products. A surprising experimental result was failure of most of the clamps used to mechanically fasten the connections. This indicates that the durability of clamps also need to be addressed ensure longevity of the duct connection. An accelerated test method developed during this study has been used as the basis for an ASTM standard (E2342-03).

  7. Turbulent flame speeds in ducts and the deflagration/detonation transition

    SciTech Connect (OSTI)

    Bradley, D.; Lawes, M.; Liu, Kexin [School of Mechanical Engineering, University of Leeds, Leeds LS2 9JT (United Kingdom)

    2008-07-15T23:59:59.000Z

    A methodology is proposed for determining whether a deflagration-to-detonation transition (DDT) might occur for flame propagation along a duct with baffles, closed at the ignition end. A flammable mixture can attain a maximum turbulent burning velocity. If this is sufficiently high, a strong shock is formed ahead of the flame. It is assumed that this maximum burning velocity is soon attained and on the basis of previous studies, this value can be obtained for the given conditions. The increase in temperature and pressure of the reactants, due to the shock, further increases the maximum turbulent burning velocity. The gas velocity ahead of the flame is linked to one-dimensional shock wave equations in a numerical analysis. The predicted duct flame speeds with the appropriate maximum turbulent burning velocities are in good agreement with those measured in the slow and fast flame regimes of a range of CH{sub 4}-air and H{sub 2}-air mixtures. DDTs are possible if autoignition of the reactants occurs in the time available, and if the projected flame speed approaches the Chapman-Jouguet velocity at the same temperature and pressure. Prediction of the first condition requires values of the autoignition delay time of the mixture at the shocked temperatures and pressures. Prediction of the second requires values of the laminar burning velocity and Markstein number. With the appropriate values of these parameters, it is shown numerically that there is no DDT with CH{sub 4}-air. With H{sub 2}-air, the onset of DDT occurs close to the values of equivalence ratio at which it has been observed experimentally. The effects of different duct sizes also are predicted, although details of the DDT cannot be predicted. Extension of the study to a wider range of fuels requires more data on their laminar burning velocities and Markstein numbers at higher temperatures and pressures and on autoignition delay times at lower temperatures and pressures. (author)

  8. STATE OF CALIFORNIA DUCT LEAKAGE TEST EXISTING DUCT SYSTEM

    E-Print Network [OSTI]

    2010 Outside air (OA) ducts for Central Fan Integrated (CFI) ventilation systems, shall not be sealed

  9. Flat Oval Spiral Duct Deflection

    E-Print Network [OSTI]

    Daugherty, Matthew

    2014-03-10T23:59:59.000Z

    , because it has less flat surfaces than rectangular duct. Flat oval can be fit in tight places because of its similar aspect ratio to rectangular duct. [23] 2.6 Duct Selection and Application All ducts are required to be sealed, but leakage testing...

  10. HIGH-VELOCITY CLOUDS IN THE NEARBY SPIRAL GALAXY M 83

    E-Print Network [OSTI]

    Miller, Eric D.

    We present deep H I 21 cm and optical observations of the face-on spiral galaxy M 83 obtained as part of a project to search for high-velocity clouds (HVCs) in nearby galaxies. Anomalous-velocity neutral gas is detected ...

  11. Experiments measuring particle deposition from fully developed turbulent flow in ventilation ducts

    SciTech Connect (OSTI)

    Sippola, Mark R.; Nazaroff, William W.

    2003-08-01T23:59:59.000Z

    Particle deposition in ventilation ducts influences particle exposures of building occupants and may lead to a variety of indoor air quality concerns. Experiments have been performed in a laboratory to study the effects of particle size and air speed on deposition rates of particles from turbulent air flows in galvanized steel and internally insulated ducts with hydraulic diameters of 15.2 cm. The duct systems were constructed of materials typically found in commercial heating, ventilating and air conditioning (HVAC) systems. In the steel duct system, experiments with nominal particle sizes of 1, 3, 5, 9 and 16 {micro}m were conducted at each of three nominal air speeds: 2.2, 5.3 and 9.0 m/s. In the insulated duct system, deposition rates of particles with nominal sizes of 1, 3, 5, 8 and 13 {micro}m were measured at nominal air speeds of 2.2, 5.3 and 8.8 m/s. Fluorescent techniques were used to directly measure the deposition velocities of monodisperse fluorescent particles to duct surfaces (floor, wall and ceiling) at two straight duct sections where the turbulent flow profile was fully developed. In steel ducts, deposition rates were higher to the duct floor than to the wall, which were, in turn, greater than to the ceiling. In insulated ducts, deposition was nearly the same to the duct floor, wall and ceiling for a given particle size and air speed. Deposition to duct walls and ceilings was greatly enhanced in insulated ducts compared to steel ducts. Deposition velocities to each of the three duct surface orientations in both systems were found to increase with increasing particle size or air velocity over the ranges studied. Deposition rates measured in the current experiments were in general agreement with the limited observations of similar systems by previous researchers.

  12. Hohlraum Designs for High Velocity Implosions on NIF

    SciTech Connect (OSTI)

    Meezan, N B; Hicks, D G; Callahan, D A; Olson, R E; Schneider, M S; Thomas, C A; Robey, H F; Celliers, P M; Kline, J K; Dixit, S N; Michel, P A; Jones, O S; Clark, D S; Ralph, J E; Doeppner, T; MacKinnon, A J; Haan, S W; Landen, O L; Glenzer, S H; Suter, L J; Edwards, M J; Macgowan, B J; Lindl, J D; Atherton, L J

    2011-10-19T23:59:59.000Z

    In this paper, we compare experimental shock and capsule trajectories to design calculations using the radiation-hydrodynamics code HYDRA. The measured trajectories from surrogate ignition targets are consistent with reducing the x-ray flux on the capsule by about 85%. A new method of extracting the radiation temperature as seen by the capsule from x-ray intensity and image data shows that about half of the apparent 15% flux deficit in the data with respect to the simulations can be explained by HYDRA overestimating the x-ray flux on the capsule. The National Ignition Campaign (NIC) point-design target is designed to reach a peak fuel-layer velocity of 370 km/s by ablating 90% of its plastic (CH) ablator. The 192-beam National Ignition Facility laser drives a gold hohlraum to a radiation temperature (T{sub RAD}) of 300 eV with a 20 ns-long, 420 TW, 1.3 MJ laser pulse. The hohlraum x-rays couple to the CH ablator in order to apply the required pressure to the outside of the capsule. In this paper, we compare experimental measurements of the hohlraum T{sub RAD} and the implosion trajectory with design calculations using the code hydra. The measured radial positions of the leading shock wave and the unablated shell are consistent with simulations in which the x-ray flux on the capsule is artificially reduced by 85%. We describe a new method of inferring the T{sub RAD} seen by the capsule from time-dependent x-ray intensity data and static x-ray images. This analysis shows that hydra overestimates the x-ray flux incident on the capsule by {approx}8%.

  13. Doppler-Shift Asymmetry in High-Velocity Maser Emission from Shocks in Circumnuclear Disks

    E-Print Network [OSTI]

    Eyal Maoz; Christopher F. McKee

    1997-04-04T23:59:59.000Z

    SHORT VERSION: The rapidly rotating, masing circumnuclear disk in the central sub-parsec region of the galaxy NGC 4258 is remarkably circular and Keplerian, yet a striking asymmetry appears in the maser spectrum: the red-shifted, high- velocity sources are much more numerous and significantly more intense than the blue-shifted ones. A similar strong asymmetry appears also in the recently discovered, masing, circumnuclear disks in NGC 1068 and NGC 4945, thus suggesting it may be a general phenomenon. We show that the observed Doppler-shift asymmetry can naturally arise due to spiral shocks in circumnuclear disks, independent of the existence of a warp in the disk or the azimuthal direction to the observer. The high velocities of these features reflect the rotational velocities in the disk, and have nothing to do with the shock speed. In NGC 4258 - the currently most well-defined masing disk - the proposed scenario can also account for the intriguing clustering of the high-velocity maser spots in distinct clumps, the restricted spatial distribution of the low-velocity sources, and the dip in the maser spectrum at the systemic velocity of the disk. In this case we infer a disk mass of ~10E4 M_sun and a mass accretion rate of order ~7E-3 M_sun/year, which may be consistent with an advection-dominated accretion flow. The model is consistent with the observed Keplerian rotation, and introduces only negligible corrections to the previously derived black hole mass and galaxy distance. Predictions include slow systematic drifts in the velocity and position of all the high-velocity features, and the existence of circumnuclear disks which are delineated only by high-velocity maser emission.

  14. Morphological Characteristics of Compact High-Velocity Clouds Revealed by High-Resolution WSRT Imaging

    E-Print Network [OSTI]

    W. B. Burton; Robert Braun

    1999-12-22T23:59:59.000Z

    A class of compact, isolated high-velocity clouds which plausibly represents a homogeneous subsample of the HVC phenomenon in a single physical state was objectively identified by Braun and Burton (1999). Six examples of the CHVCs, unresolved in single-dish data, have been imaged with the Westerbork Synthesis Radio Telescope. The high-resolution imaging reveals the morphology of these objects, including a core/halo distribution of fluxes, signatures of rotation indicating dark matter, and narrow linewidths constraining the kinetic temperature of several opaque cores. In these regards, as well as in their kinematic and spatial deployment on the sky, the CHVC objects are evidently a dynamically cold ensemble of dark-matter-dominated HI clouds accreting onto the Local Group in a continuing process of galactic evolution.

  15. Consolidated solutions to rectangular air duct design by graphical methods

    E-Print Network [OSTI]

    Otts, John Graves

    1953-01-01T23:59:59.000Z

    . It is the purpose of this paper to study the present buo de- sign charts an4 te present sam other ~ of solving tbe seas data in less coaplieated consolidated instrueents. PROCR?gQ LLvv ~ prccoihne in 4esigaiag ~ duct systea is ss follows& l. Study tb? buil41ag... to the outLets. With this infoniistioa it is possible to calculate the duct nines, deter?inc the friction Loss of each section, and. obtain the total pressure loss in the systea. yriction thod. The initial velocity in ths duct at the fan is deterainsd...

  16. Burning Velocities in Catalytically Assisted Self-Propagating High-Temperature Combustion Synthesis Systems

    E-Print Network [OSTI]

    Wooldridge, Margaret S.

    Burning Velocities in Catalytically Assisted Self-Propagating High-Temperature Combustion Synthesis of catalytically assisted self-propagating high-temperature synthesis (SHS) of the tantalum/carbon material system. © 2001 by The Combustion Institute INTRODUCTION Self-propagating high-temperature combustion synthesis

  17. Particle deposition in ventilation ducts

    SciTech Connect (OSTI)

    Sippola, Mark R.

    2002-09-01T23:59:59.000Z

    Exposure to airborne particles is detrimental to human health and indoor exposures dominate total exposures for most people. The accidental or intentional release of aerosolized chemical and biological agents within or near a building can lead to exposures of building occupants to hazardous agents and costly building remediation. Particle deposition in heating, ventilation and air-conditioning (HVAC) systems may significantly influence exposures to particles indoors, diminish HVAC performance and lead to secondary pollutant release within buildings. This dissertation advances the understanding of particle behavior in HVAC systems and the fates of indoor particles by means of experiments and modeling. Laboratory experiments were conducted to quantify particle deposition rates in horizontal ventilation ducts using real HVAC materials. Particle deposition experiments were conducted in steel and internally insulated ducts at air speeds typically found in ventilation ducts, 2-9 m/s. Behaviors of monodisperse particles with diameters in the size range 1-16 {micro}m were investigated. Deposition rates were measured in straight ducts with a fully developed turbulent flow profile, straight ducts with a developing turbulent flow profile, in duct bends and at S-connector pieces located at duct junctions. In straight ducts with fully developed turbulence, experiments showed deposition rates to be highest at duct floors, intermediate at duct walls, and lowest at duct ceilings. Deposition rates to a given surface increased with an increase in particle size or air speed. Deposition was much higher in internally insulated ducts than in uninsulated steel ducts. In most cases, deposition in straight ducts with developing turbulence, in duct bends and at S-connectors at duct junctions was higher than in straight ducts with fully developed turbulence. Measured deposition rates were generally higher than predicted by published models. A model incorporating empirical equations based on the experimental measurements was applied to evaluate particle losses in supply and return duct runs. Model results suggest that duct losses are negligible for particle sizes less than 1 {micro}m and complete for particle sizes greater than 50 {micro}m. Deposition to insulated ducts, horizontal duct floors and bends are predicted to control losses in duct systems. When combined with models for HVAC filtration and deposition to indoor surfaces to predict the ultimate fates of particles within buildings, these results suggest that ventilation ducts play only a small role in determining indoor particle concentrations, especially when HVAC filtration is present. However, the measured and modeled particle deposition rates are expected to be important for ventilation system contamination.

  18. High-resolution imaging of compact high-velocity clouds (II)

    E-Print Network [OSTI]

    V. de Heij; R. Braun; W. B. Burton

    2002-06-19T23:59:59.000Z

    We have imaged five compact high-velocity clouds in HI with arcmin angular- and km/s spectral-resolution using the WSRT. Supplementary total-power data, which is fully sensitive to both the cool and warm components of HI, is available for comparison for all the sources, albeit with angular resolutions that vary from 3' to 36'. The fractional HI flux in compact CNM components varies from 4% to 16% in our sample. All objects have at least one local peak in the CNM column which exceeds about 10^19 cm^-2 when observed with arcmin resolution. It is plausible that a peak column density of 1-2x10^19 cm^-2 is a prerequisite for the long-term survival of these sources. One object in our sample, CHVC120-20-443 (Davies' cloud), lies in close projected proximity to the disk of M31. This object is characterized by exceptionally broad linewidths in its CNM concentrations (more than 5 times greater than the median value). These CNM concentrations lie in an arc on the edge of the source facing the M31 disk, while the diffuse HI component of this source has a position offset in the direction of the disk. All of these attributes suggest that CHVC120-20-443 is in a different evolutionary state than most of the other CHVCs which have been studied. Similarly broad CNM linewidths have only been detected in one other object, CHVC111-07-466, which also lies in the Local Group barycenter direction and has the most extreme radial velocity known. A distinct possibility for Davies' cloud seems to be physical interaction of some type with M31. The most likely form of this interaction might be the ram-pressure or tidal- stripping by either one of M31's visible dwarf companions, M32 or NGC205, or else by a dark companion with an associated HI condensation.

  19. An analysis of fluid flow by electrical analogy as applied to air ducts

    E-Print Network [OSTI]

    Howard, Charles Pinto

    1951-01-01T23:59:59.000Z

    system, but is is always desirable to supply them. (4) Static regain method. This method employs the static pressure regain as the velocity is reduced in a duct sys- tem. One of the most satisfactory modifications consists of reducing the velocity.... . . . . . . . . . 29 1, Recommended and Maximum Duct Velocities ~ . ~, . . . ~ ~ 2. Results for Constant Pressure Drop Method. . . . . . . . 14 3. Results of Total Pressure Drop Method. . . . . . ~. . . 20 Results of Trial I for Metwork Calculator AppU. ed...

  20. Cornice Duct System

    SciTech Connect (OSTI)

    Wayne Place; Chuck Ladd

    2004-10-29T23:59:59.000Z

    SYNERGETICS, INC., has designed, developed, and tested an air handling duct system that integrates the air duct with the cornice trim of interior spaces. The device has the advantage that the normal thermal losses from ducts into unconditioned attics and crawl spaces can be totally eliminated by bringing the ducts internal to the conditioned space. The following report details work conducted in the second budget period to develop the Cornice Duct System into a viable product for use in a variety of residential or small commercial building settings. A full-scale prototype has been fabricated and tested in a laboratory test building at the Daylighting Facility at North Carolina State University., Based on the results of that testing, the prototype design as been refined, fabricated, installed, and extensively tested in a residential laboratory house. The testing indicates that the device gives substantially superior performance to a standard air distribution system in terms of energy performance and thermal comfort. Patent Number US 6,511,373 B2 has been granted on the version of the device installed and tested in the laboratory house. (A copy of that patent is attached.) Refinements to the device have been carried through two additional design iterations, with a particular focus on reducing installation time and cost and refining the air control system. These new designs have been fabricated and tested and show substantial promise. Based on these design and testing iterations, a final design is proposed as part of this document. That final design is the basis for a continuation in part currently being filed with the U.5, Patent office.

  1. HIGH-VELOCITY CLOUDS IN THE GALACTIC ALL SKY SURVEY. I. CATALOG

    SciTech Connect (OSTI)

    Moss, V. A.; Kummerfeld, J. K. [Sydney Institute for Astronomy, School of Physics A29, University of Sydney, Sydney, NSW 2006 (Australia); McClure-Griffiths, N. M.; Murphy, T. [CSIRO Astronomy and Space Science, ATNF, P.O. Box 76, Epping, NSW 1710 (Australia); Pisano, D. J. [Department of Physics, West Virginia University, P.O. Box 6315, Morgantown, WV 26506 (United States); Curran, J. R., E-mail: vmoss@physics.usyd.edu.au [School of Information Technologies, University of Sydney, Sydney, NSW 2006 (Australia)

    2013-11-01T23:59:59.000Z

    We present a catalog of high-velocity clouds (HVCs) from the Galactic All Sky Survey (GASS) of southern sky neutral hydrogen, which has 57 mK sensitivity and 1 km s{sup –1} velocity resolution and was obtained with the Parkes Telescope. Our catalog has been derived from the stray-radiation-corrected second release of GASS. We describe the data and our method of identifying HVCs and analyze the overall properties of the GASS population. We catalog a total of 1693 HVCs at declinations <0°, including 1111 positive velocity HVCs and 582 negative velocity HVCs. Our catalog also includes 295 anomalous velocity clouds (AVCs). The cloud line-widths of our HVC population have a median FWHM of ?19 km s{sup –1}, which is lower than that found in previous surveys. The completeness of our catalog is above 95% based on comparison with the HIPASS catalog of HVCs upon which we improve by an order of magnitude in spectral resolution. We find 758 new HVCs and AVCs with no HIPASS counterpart. The GASS catalog will shed unprecedented light on the distribution and kinematic structure of southern sky HVCs, as well as delve further into the cloud populations that make up the anomalous velocity gas of the Milky Way.

  2. High-resolution velocity field imaging around a borehole: Excavation Damaged Zone characterization

    E-Print Network [OSTI]

    Boyer, Edmond

    .balland@ineris.fr, vincent.renaud@ineris.fr ABSTRACT The excavation of a deep underground structure induces a stress field of a material. In the case of underground storage, rock damage will affect the rock capacity to confine1 High-resolution velocity field imaging around a borehole: Excavation Damaged Zone

  3. Method and apparatus for optical Doppler tomographic imaging of fluid flow velocity in highly scattering media

    DOE Patents [OSTI]

    Nelson, John Stuart (Laguna Niguel, CA); Milner, Thomas Edward (Irvine, CA); Chen, Zhongping (Irvine, CA)

    1999-01-01T23:59:59.000Z

    Optical Doppler tomography permits imaging of fluid flow velocity in highly scattering media. The tomography system combines Doppler velocimetry with high spatial resolution of partially coherent optical interferometry to measure fluid flow velocity at discrete spatial locations. Noninvasive in vivo imaging of blood flow dynamics and tissue structures with high spatial resolutions of the order of 2 to 10 microns is achieved in biological systems. The backscattered interference signals derived from the interferometer may be analyzed either through power spectrum determination to obtain the position and velocity of each particle in the fluid flow sample at each pixel, or the interference spectral density may be analyzed at each frequency in the spectrum to obtain the positions and velocities of the particles in a cross-section to which the interference spectral density corresponds. The realized resolutions of optical Doppler tomography allows noninvasive in vivo imaging of both blood microcirculation and tissue structure surrounding the vessel which has significance for biomedical research and clinical applications.

  4. A confirmed location in the Galactic halo for the high-velocity cloud 'chain A'

    E-Print Network [OSTI]

    Hugo van Woerden; Ulrich J. Schwarz; Reynier F. Peletier; Bart P. Wakker; Peter M. W. Kalberla

    1999-07-08T23:59:59.000Z

    The high-velocity clouds of atomic hydrogen, discovered about 35 years ago, have velocities inconsistent with simple Galactic rotation models that generally fit the stars and gas in the Milky Way disk. Their origins and role in Galactic evolution remain poorly understood, largely for lack of information on their distances. The high-velocity clouds might result from gas blown from the Milky Way disk into the halo by supernovae, in which case they would enrich the Galaxy with heavy elements as they fall back onto the disk. Alternatively, they may consist of metal-poor gas -- remnants of the era of galaxy formation, accreted by the Galaxy and reducing its metal abundance. Or they might be truly extragalactic objects in the Local Group of galaxies. Here we report a firm distance bracket for a large high-velocity cloud, Chain A, which places it in the Milky Way halo (2.5 to 7 kiloparsecs above the Galactic plane), rather than at an extragalactic distance, and constrains its gas mass to between 10^5 and 2 times 10^6 solar masses.

  5. A confirmed location in the Galactic halo for the high-velocity cloud "chain A"

    E-Print Network [OSTI]

    Van Woerden, H; Peletier, R F; Wakker, B P; Kalberla, P M W; Woerden, Hugo van; Schwarz, Ulrich J.; Peletier, Reynier F.; Wakker, Bart P.; Kalberla, Peter M.W.

    1999-01-01T23:59:59.000Z

    The high-velocity clouds of atomic hydrogen, discovered about 35 years ago, have velocities inconsistent with simple Galactic rotation models that generally fit the stars and gas in the Milky Way disk. Their origins and role in Galactic evolution remain poorly understood, largely for lack of information on their distances. The high-velocity clouds might result from gas blown from the Milky Way disk into the halo by supernovae, in which case they would enrich the Galaxy with heavy elements as they fall back onto the disk. Alternatively, they may consist of metal-poor gas -- remnants of the era of galaxy formation, accreted by the Galaxy and reducing its metal abundance. Or they might be truly extragalactic objects in the Local Group of galaxies. Here we report a firm distance bracket for a large high-velocity cloud, Chain A, which places it in the Milky Way halo (2.5 to 7 kiloparsecs above the Galactic plane), rather than at an extragalactic distance, and constrains its gas mass to between 10^5 and 2 times 10^...

  6. High-Velocity Features of Calcium and Silicon in the Spectra of Type Ia Supernovae

    E-Print Network [OSTI]

    Silverman, Jeffrey M; Marion, G H; Wheeler, J Craig; Barna, Barnabas; Szalai, Tamas; Mulligan, Brian; Filippenko, Alexei V

    2015-01-01T23:59:59.000Z

    "High-velocity features" (HVFs) are spectral features in Type Ia supernovae (SNe Ia) that have minima indicating significantly higher (by greater than about 6000 km/s) velocities than typical "photospheric-velocity features" (PVFs). The PVFs are absorption features with minima indicating typical photospheric (i.e., bulk ejecta) velocities (usually ~9000-15,000 km/s near B-band maximum brightness). In this work we undertake the most in-depth study of HVFs ever performed. The dataset used herein consists of 445 low-resolution optical and near-infrared (NIR) spectra (at epochs up to 5 d past maximum brightness) of 210 low-redshift SNe Ia that follow the "Phillips relation." A series of Gaussian functions is fit to the data in order to characterise possible HVFs of Ca II H&K, Si II {\\lambda}6355, and the Ca II NIR triplet. The temporal evolution of the velocities and strengths of the PVFs and HVFs of these three spectral features is investigated, as are possible correlations with other SN Ia observables. We f...

  7. Laser Doppler field sensor for high resolution flow velocity imaging without camera

    SciTech Connect (OSTI)

    Voigt, Andreas; Bayer, Christian; Shirai, Katsuaki; Buettner, Lars; Czarske, Juergen

    2008-09-20T23:59:59.000Z

    In this paper we present a laser sensor for highly spatially resolved flow imaging without using a camera. The sensor is an extension of the principle of laser Doppler anemometry (LDA). Instead of a parallel fringe system, diverging and converging fringes are employed. This method facilitates the determination of the tracer particle position within the measurement volume and leads to an increased spatial and velocity resolution compared to conventional LDA. Using a total number of four fringe systems the flow is resolved in two spatial dimensions and the orthogonal velocity component. Since no camera is used, the resolution of the sensor is not influenced by pixel size effects. A spatial resolution of 4 {mu}m in the x direction and 16 {mu}m in the y direction and a relative velocity resolution of 1x10{sup -3} have been demonstrated up to now. As a first application we present the velocity measurement of an injection nozzle flow. The sensor is also highly suitable for applications in nano- and microfluidics, e.g., for the measurement of flow rates.

  8. Duct thermal performance models for large commercial buildings

    SciTech Connect (OSTI)

    Wray, Craig P.

    2003-10-01T23:59:59.000Z

    Despite the potential for significant energy savings by reducing duct leakage or other thermal losses from duct systems in large commercial buildings, California Title 24 has no provisions to credit energy-efficient duct systems in these buildings. A substantial reason is the lack of readily available simulation tools to demonstrate the energy-saving benefits associated with efficient duct systems in large commercial buildings. The overall goal of the Efficient Distribution Systems (EDS) project within the PIER High Performance Commercial Building Systems Program is to bridge the gaps in current duct thermal performance modeling capabilities, and to expand our understanding of duct thermal performance in California large commercial buildings. As steps toward this goal, our strategy in the EDS project involves two parts: (1) developing a whole-building energy simulation approach for analyzing duct thermal performance in large commercial buildings, and (2) using the tool to identify the energy impacts of duct leakage in California large commercial buildings, in support of future recommendations to address duct performance in the Title 24 Energy Efficiency Standards for Nonresidential Buildings. The specific technical objectives for the EDS project were to: (1) Identify a near-term whole-building energy simulation approach that can be used in the impacts analysis task of this project (see Objective 3), with little or no modification. A secondary objective is to recommend how to proceed with long-term development of an improved compliance tool for Title 24 that addresses duct thermal performance. (2) Develop an Alternative Calculation Method (ACM) change proposal to include a new metric for thermal distribution system efficiency in the reporting requirements for the 2005 Title 24 Standards. The metric will facilitate future comparisons of different system types using a common ''yardstick''. (3) Using the selected near-term simulation approach, assess the impacts of duct system improvements in California large commercial buildings, over a range of building vintages and climates. This assessment will provide a solid foundation for future efforts that address the energy efficiency of large commercial duct systems in Title 24. This report describes our work to address Objective 1, which includes a review of past modeling efforts related to duct thermal performance, and recommends near- and long-term modeling approaches for analyzing duct thermal performance in large commercial buildings.

  9. SPECTROSCOPIC OBSERVATIONS OF SN 2012fr: A LUMINOUS, NORMAL TYPE Ia SUPERNOVA WITH EARLY HIGH-VELOCITY FEATURES AND A LATE VELOCITY PLATEAU

    SciTech Connect (OSTI)

    Childress, M. J.; Scalzo, R. A.; Sim, S. A.; Tucker, B. E.; Yuan, F.; Schmidt, B. P. [Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611 (Australia); Cenko, S. B.; Filippenko, A. V. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Silverman, J. M. [Department of Astronomy, University of Texas, Austin, TX 78712-0259 (United States); Contreras, C.; Hsiao, E. Y.; Phillips, M.; Morrell, N. [Las Campanas Observatory, Carnegie Observatories, Casilla 601, La Serena (Chile); Jha, S. W.; McCully, C. [Department of Physics and Astronomy, Rutgers, State University of New Jersey, 136 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Anderson, J. P.; De Jaeger, T.; Forster, F. [Departamento de Astronomia, Universidad de Chile, Casilla 36-D, Santiago (Chile); Benetti, S. [INAF Osservatorio Astronomico di Padova, Vicolo dell'Osservatorio 5, I-35122 Padova (Italy); Bufano, F., E-mail: mjc@mso.anu.edu.au [Departamento de Ciencias Fisicas, Universidad Andres Bello, Avda. Republica 252, Santiago (Chile); and others

    2013-06-10T23:59:59.000Z

    We present 65 optical spectra of the Type Ia SN 2012fr, 33 of which were obtained before maximum light. At early times, SN 2012fr shows clear evidence of a high-velocity feature (HVF) in the Si II {lambda}6355 line that can be cleanly decoupled from the lower velocity ''photospheric'' component. This Si II {lambda}6355 HVF fades by phase -5; subsequently, the photospheric component exhibits a very narrow velocity width and remains at a nearly constant velocity of {approx}12,000 km s{sup -1} until at least five weeks after maximum brightness. The Ca II infrared triplet exhibits similar evidence for both a photospheric component at v Almost-Equal-To 12,000 km s{sup -1} with narrow line width and long velocity plateau, as well as an HVF beginning at v Almost-Equal-To 31,000 km s{sup -1} two weeks before maximum. SN 2012fr resides on the border between the ''shallow silicon'' and ''core-normal'' subclasses in the Branch et al. classification scheme, and on the border between normal and high-velocity Type Ia supernovae (SNe Ia) in the Wang et al. system. Though it is a clear member of the ''low velocity gradient'' group of SNe Ia and exhibits a very slow light-curve decline, it shows key dissimilarities with the overluminous SN 1991T or SN 1999aa subclasses of SNe Ia. SN 2012fr represents a well-observed SN Ia at the luminous end of the normal SN Ia distribution and a key transitional event between nominal spectroscopic subclasses of SNe Ia.

  10. Higher velocity, high-foot implosions on the National Ignition Facility laser

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Callahan, D. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)] (ORCID:0000000315498916); Hurricane, O. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hinkel, D. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Döppner, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ma, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Park, H. -S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Barrios Garcia, M. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Berzak Hopkins, L. F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)] (ORCID:0000000291875667); Casey, D. T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Cerjan, C. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)] (ORCID:0000000251686845); Dewald, E. L. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Dittrich, T. R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Edwards, M. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Haan, S. W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)] (ORCID:0000000184045131); Hamza, A. V. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kline, J. L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Knauer, J. P. [Univ. of Rochester, NY (United States); Kritcher, A. L. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Landen, O. L. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); LePape, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); MacPhee, A. G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)] (ORCID:0000000341604479); Milovich, J. L. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Nikroo, A. [General Atomics, San Diego, CA (United States)] (ORCID:0000000288550378); Pak, A. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Patel, P. K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Rygg, J. R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ralph, J. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Salmonson, J. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Spears, B. K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Springer, P. T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Tommasini, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Benedetti, L. R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bionta, R. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bond, E. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bradley, D. K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Caggiano, J. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Field, J. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Fittinghoff, D. N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Frenje, J. [MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States)] (ORCID:0000000168460378); Gatu Johnson, M. [MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States); Grim, G. P. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hatarik, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Merrill, F. E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Nagel, S. R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)] (ORCID:0000000277686819); Izumi, N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Khan, S. F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-05-01T23:59:59.000Z

    By increasing the velocity in “high foot” implosions [Dittrich et al., Phys. Rev. Lett. 112, 055002 (2014); Park et al., Phys. Rev. Lett. 112, 055001 (2014); Hurricane et al., Nature 506, 343 (2014); Hurricane et al., Phys. Plasmas 21, 056314 (2014)] on the National Ignition Facility laser, we have nearly doubled the neutron yield and the hotspot pressure as compared to the implosions reported upon last year. The implosion velocity has been increased using a combination of the laser (higher power and energy), the hohlraum (depleted uranium wall material with higher opacity and lower specific heat than gold hohlraums), and the capsule (thinner capsules with less mass). We find that the neutron yield from these experiments scales systematically with a velocity-like parameter of the square root of the laser energy divided by the ablator mass. By connecting this parameter with the inferred implosion velocity (v), we find that for shots with primary yield >1e15 neutrons, the total yield ~ v???. This increase is considerably faster than the expected dependence for implosions without alpha heating ( ~v???) and is additional evidence that these experiments have significant alpha heating.

  11. Higher velocity, high-foot implosions on the National Ignition Facility laser

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Callahan, D. A.; Hurricane, O. A.; Hinkel, D. E.; Döppner, T.; Ma, T.; Park, H. -S.; Barrios Garcia, M. A.; Berzak Hopkins, L. F.; Casey, D. T.; Cerjan, C. J.; et al

    2015-05-01T23:59:59.000Z

    By increasing the velocity in “high foot” implosions [Dittrich et al., Phys. Rev. Lett. 112, 055002 (2014); Park et al., Phys. Rev. Lett. 112, 055001 (2014); Hurricane et al., Nature 506, 343 (2014); Hurricane et al., Phys. Plasmas 21, 056314 (2014)] on the National Ignition Facility laser, we have nearly doubled the neutron yield and the hotspot pressure as compared to the implosions reported upon last year. The implosion velocity has been increased using a combination of the laser (higher power and energy), the hohlraum (depleted uranium wall material with higher opacity and lower specific heat than gold hohlraums), andmore »the capsule (thinner capsules with less mass). We find that the neutron yield from these experiments scales systematically with a velocity-like parameter of the square root of the laser energy divided by the ablator mass. By connecting this parameter with the inferred implosion velocity (v), we find that for shots with primary yield >1e15 neutrons, the total yield ~ v???. This increase is considerably faster than the expected dependence for implosions without alpha heating ( ~v???) and is additional evidence that these experiments have significant alpha heating.« less

  12. Westerbork HI observations of high-velocity clouds near M31 and M33

    E-Print Network [OSTI]

    T. Westmeier; R. Braun; D. Thilker

    2005-03-10T23:59:59.000Z

    We have undertaken high-resolution follow-up of a sample of high velocity HI clouds apparently associated with M31. Our sample was chosen from the population of high-velocity clouds (HVCs) detected out to 50 kpc projected radius of the Andromeda Galaxy by Thilker et al. (2004) with the Green Bank Telescope. Nine pointings were observed with the Westerbork Synthesis Radio Telescope to determine the physical parameters of these objects and to find clues to their origin. One additional pointing was directed at a similar object near M33. At 2' resolution we detect 16 individual HVCs around M31 and 1 HVC near M33 with typical HI masses of a few times 10^5 solar masses and sizes of the order of 1 kpc. Estimates of the dynamical and virial masses of some of the HVCs indicate that they are likely gravitationally dominated by additional mass components such as dark matter or ionised gas. Twelve of the clouds are concentrated in an area of only 1 by 1 degree at a projected separation of less than 15 kpc from the disk of M31. This HVC complex has a rather complicated morphological and kinematical structure and partly overlaps with the giant stellar stream of M31, suggesting a tidal origin. Another detected feature is in close proximity, in both position and velocity, with NGC 205, perhaps also indicative of tidal processes. Other HVCs in our survey are isolated and might represent primordial, dark-matter dominated clouds.

  13. The Kinematic and Spatial Deployment of Compact, Isolated High-Velocity Clouds

    E-Print Network [OSTI]

    R. Braun; W. B. Burton

    1998-10-27T23:59:59.000Z

    We have identified a class of high-velocity clouds which are compact and apparently isolated. The clouds are compact in that they have angular sizes less than 2 degrees FWHM. They are isolated in that they are separated from neighboring emission by expanses where no emission is seen to the detection limit of the available data. Candidates for inclusion in this class were extracted from the Leiden/Dwingeloo HI survey of Hartmann & Burton and from the Wakker & van Woerden catalogue of high-velocity clouds. The candidates were subject to independent confirmation using either the 25-meter telescope in Dwingeloo or the 140-foot telescope in Green Bank. We argue that the resulting list, even if incomplete, is sufficiently representative of the ensemble of compact, isolated HVCs - CHVCs - that the characteristics of their disposition on the sky, and of their kinematics, are revealing of some physical aspects of the class. The CHVCs are in fact distributed quite uniformly across the sky. A global search for the reference frame which minimizes the velocity dispersion of the ensemble returns the Local Group Standard of Rest with high confidence. The CHVCs are not stationary with respect to this reference frame but have a mean infall velocity of 100 km/s. These properties are strongly suggestive of a population which has as yet had little interaction with the more massive Local Group members. At a typical distance of about 1 Mpc these objects would have sizes of about 15 kpc and gas masses, M_HI, of a few times 10^7 M_Sun, corresponding to those of (sub-)dwarf galaxies. (abridged)

  14. Aerogel Impregnated Polyurethane Piping and Duct Insulation ...

    Energy Savers [EERE]

    Aerogel Impregnated Polyurethane Piping and Duct Insulation Aerogel Impregnated Polyurethane Piping and Duct Insulation Emerging Technologies Project for the 2013 Building...

  15. Mapping High-velocity H-alpha and Lyman-alpha Emission from Supernova 1987A

    E-Print Network [OSTI]

    France, Kevin; Fransson, Claes; Larsson, Josefin; Frank, Kari A; Burrows, David N; Challis, Peter; Kirshner, Robert P; Chevalier, Roger A; Garnavich, Peter; Heng, Kevin; Lawrence, Stephen S; Lundqvist, Peter; Smith, Nathan; Sonneborn, George

    2015-01-01T23:59:59.000Z

    We present new {\\it Hubble Space Telescope} images of high-velocity H-$\\alpha$ and Lyman-$\\alpha$ emission in the outer debris of SN~1987A. The H-$\\alpha$ images are dominated by emission from hydrogen atoms crossing the reverse shock. For the first time we observe emission from the reverse shock surface well above and below the equatorial ring, suggesting a bipolar or conical structure perpendicular to the ring plane. Using the H$\\alpha$ imaging, we measure the mass flux of hydrogen atoms crossing the reverse shock front, in the velocity intervals ($-$7,500~$<$~$V_{obs}$~$<$~$-$2,800 km s$^{-1}$) and (1,000~$<$~$V_{obs}$~$<$~7,500 km s$^{-1}$), $\\dot{M_{H}}$ = 1.2~$\\times$~10$^{-3}$ M$_{\\odot}$ yr$^{-1}$. We also present the first Lyman-$\\alpha$ imaging of the whole remnant and new $Chandra$ X-ray observations. Comparing the spatial distribution of the Lyman-$\\alpha$ and X-ray emission, we observe that the majority of the high-velocity Lyman-$\\alpha$ emission originates interior to the equatorial...

  16. PTF 12gzk—A rapidly declining, high-velocity type Ic radio supernova

    SciTech Connect (OSTI)

    Horesh, Assaf; Kulkarni, Shrinivas R. [Cahill Center for Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Corsi, Alessandra [Department of Physics, The George Washington University, 725 21st Street, NW, Washington, DC 20052 (United States); Frail, Dale A. [National Radio Astronomy Observatory, P.O. Box 0, Socorro, NM 87801 (United States); Cenko, S. Bradley [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Ben-Ami, Sagi; Gal-Yam, Avishay; Yaron, Ofer; Arcavi, Iair; Ofek, Eran O. [Department of Particle Physics and Astrophysics, The Weizmann Institute of Science, Rehovot 76100 (Israel); Kasliwal, Mansi M. [Carnegie Institution for Science, Department of Terrestrial Magnetism, 5241 Broad Branch Road, Washington, DC 20008 (United States)

    2013-11-20T23:59:59.000Z

    Only a few cases of Type Ic supernovae (SNe) with high-velocity ejecta (?0.2 c) have been discovered and studied. Here, we present our analysis of radio and X-ray observations of the Type Ic SN PTF 12gzk. The radio emission declined less than 10 days after explosion, suggesting SN ejecta expanding at high velocity (?0.3 c). The radio data also indicate that the density of the circumstellar material (CSM) around the supernova is lower by a factor of ?10 than the CSM around normal Type Ic SNe. PTF 12gzk may therefore be an intermediate event between a 'normal' SN Ic and a gamma-ray-burst-SN-like event. Our observations of this rapidly declining radio SN at a distance of 58 Mpc demonstrates the potential to detect many additional radio SNe, given the new capabilities of the Very Large Array (improved sensitivity and dynamic scheduling), which are currently missed, leading to a biased view of radio SNe Ic. Early optical discovery followed by rapid radio observations would provide a full description of the ejecta velocity distribution and CSM densities around stripped massive star explosions as well as strong clues about the nature of their progenitor stars.

  17. A Compact Circumstellar Shell as the Source of High--velocity Features in SN 2011fe

    E-Print Network [OSTI]

    Mulligan, Brian W

    2015-01-01T23:59:59.000Z

    High--velocity features (HVF), especially of Ca II, are frequently seen in Type Ia supernovae observed prior to B-band maximum (Bmax). These HVF start at more than 25,000 km/s in the days after first light, and slow to about 18,000 km/s near Bmax. To recreate the Ca II near-infrared triplet (CaNIR) HVF in SN 2011fe, we consider the interaction between a Type Ia supernova and a compact circumstellar shell, employing a hydrodynamic 1-D simulation using FLASH. We generate synthetic spectra from the hydrodynamic results using syn++. We show that the CaNIR HVF and its velocity evolution is better explained by a supernova model interacting with a shell than a model without a shell, and briefly discuss the implications for progenitor models.

  18. Revisit of the relationship between the elastic properties and sound velocities at high pressures

    SciTech Connect (OSTI)

    Wang, Chenju; Yan, Xiaozhen [National Key Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics, PO Box 919-102, Mianyang, Sichuan 621900 (China); Institute of Atomic and Molecular Sciences, Sichuan University, Chengdu 610065 (China); Xiang, Shikai, E-mail: skxiang@caep.ac.cn; Chen, Haiyan [National Key Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics, PO Box 919-102, Mianyang, Sichuan 621900 (China); Gu, Jianbing; Yu, Yin [National Key Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics, PO Box 919-102, Mianyang, Sichuan 621900 (China); College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China); Kuang, Xiaoyu [Institute of Atomic and Molecular Sciences, Sichuan University, Chengdu 610065 (China); International Centre for Materials Physics, Academia Sinica, Shenyang 110016 (China)

    2014-09-14T23:59:59.000Z

    The second-order elastic constants and stress-strain coefficients are defined, respectively, as the second derivatives of the total energy and the first derivative of the stress with respect to strain. Since the Lagrangian and infinitesimal strain are commonly used in the two definitions above, the second-order elastic constants and stress-strain coefficients are separated into two categories, respectively. In general, any of the four physical quantities is employed to characterize the elastic properties of materials without differentiation. Nevertheless, differences may exist among them at non-zero pressures, especially high pressures. Having explored the confusing issue systemically in the present work, we find that the four quantities are indeed different from each other at high pressures and these differences depend on the initial stress applied on materials. Moreover, the various relations between the four quantities depicting elastic properties of materials and high-pressure sound velocities are also derived from the elastic wave equations. As examples, we calculated the high-pressure sound velocities of cubic tantalum and hexagonal rhenium using these nexus. The excellent agreement of our results with available experimental data suggests the general applicability of the relations.

  19. Aerosol formation from high-velocity uranium drops: Comparison of number and mass distributions. Final report

    SciTech Connect (OSTI)

    Rader, D.J.; Benson, D.A.

    1995-05-01T23:59:59.000Z

    This report presents the results of an experimental study of the aerosol produced by the combustion of high-velocity molten-uranium droplets produced by the simultaneous heating and electromagnetic launch of uranium wires. These tests are intended to simulate the reduction of high-velocity fragments into aerosol in high-explosive detonations or reactor accidents involving nuclear materials. As reported earlier, the resulting aerosol consists mainly of web-like chain agglomerates. A condensation nucleus counter was used to investigate the decay of the total particle concentration due to coagulation and losses. Number size distributions based on mobility equivalent diameter obtained soon after launch with a Differential Mobility Particle Sizer showed lognormal distributions with an initial count median diameter (CMD) of 0.3 {mu}m and a geometric standard deviation, {sigma}{sub g} of about 2; the CMD was found to increase and {sigma}{sub g} decrease with time due to coagulation. Mass size distributions based on aerodynamic diameter were obtained for the first time with a Microorifice Uniform Deposit Impactor, which showed lognormal distributions with mass median aerodynamic diameters of about 0.5 {mu}m and an aerodynamic geometric standard deviation of about 2. Approximate methods for converting between number and mass distributions and between mobility and aerodynamic equivalent diameters are presented.

  20. STATE OF CALIFORNIA DUCT LEAKAGE TEST COMPLETELY NEW OR REPLACEMENT DUCT SYSTEM

    E-Print Network [OSTI]

    STATE OF CALIFORNIA DUCT LEAKAGE TEST ­ COMPLETELY NEW OR REPLACEMENT DUCT SYSTEM CEC- CF-4R TESTING CF-4R-MECH-20 Duct Leakage Test ­ Completely New or Replacement Duct System (Page 1 of 3) Site, and also for completely new or replacement duct systems in existing dwellings. For existing dwellings

  1. An automated search for high-velocity clouds in the Leiden/Dwingeloo Survey

    E-Print Network [OSTI]

    V. de Heij; R. Braun; W. B. Burton

    2002-01-15T23:59:59.000Z

    We describe an automated search through the Leiden/Dwingeloo HI Survey (LDS) for high-velocity clouds north of Dec=-28 deg. From the general catalog we extract a sample of isolated high-velocity clouds, CHVCs: anomalous-velocity HI clouds which are sharply bounded in angular extent with no kinematic or spatial connection to other HI features down to a limiting column density of 1.5*10^18cm^-2. This column density is an order of magnitude lower than the critical HI column density, about 2*10^19cm^-2, where the ionized fraction is thought to increase dramatically due to the extragalactic radiation field. As such, these objects are likely to provide their own shielding to ionizing radiation. Their small median angular size, of about 1 deg. FWHM, might then imply substantial distances, since the partially ionized HI skin in a power-law ionizing photon field has a typical exponential scale-length of 1 kpc. The automated search algorithm has been applied to the HIPASS and to the Leiden/Dwingeloo data sets. The results from the LDS are described here; Putman et al. (2002) describe application of this algorithm to the HIPASS material. We identify 67 CHVCs in the LDS which satisfy stringent requirements on isolation, and an additional 49 objects which satisfy somewhat less stringent requirements. Independent confirmation is available for all of these objects, either from earlier data in the literature or from new observations made with the Westerbork Synthesis Radio Telescope and reported here. The catalog includes 54 of the 65 CHVCs listed by Braun and Burton (1999) on the basis of a visual search of the LDS data.

  2. Seismic Technology Adapted to Analyzing and Developing Geothermal Systems Below Surface-Exposed High-Velocity Rocks

    Broader source: Energy.gov [DOE]

    Improved seismic imaging of geology across high-velocity Earth surfaces will allow more rigorous evaluation of geothermal prospects beneath volcanic outcrops. Seismic-based quantification of fracture orientation and intensity will result in optimal positioning of geothermal wells.

  3. Articulated transition duct in turbomachine

    DOE Patents [OSTI]

    Flanagan, James Scott; McMahan, Kevin Weston; LeBegue, Jeffrey Scott; Pentecost, Ronnie Ray

    2014-04-29T23:59:59.000Z

    Turbine systems are provided. A turbine system includes a transition duct comprising an inlet, an outlet, and a duct passage extending between the inlet and the outlet and defining a longitudinal axis, a radial axis, and a tangential axis. The outlet of the transition duct is offset from the inlet along the longitudinal axis and the tangential axis. The duct passage includes an upstream portion and a downstream portion. The upstream portion extends from the inlet between an inlet end and an aft end. The downstream portion extends from the outlet between an outlet end and a head end. The turbine system further includes a joint coupling the aft end of the upstream portion and the head end of the downstream portion together. The joint is configured to allow movement of the upstream portion and the downstream portion relative to each other about or along at least one axis.

  4. Impact fracture behavior of HT9 duct

    SciTech Connect (OSTI)

    Huang, F.H. [Westinghouse Hanford Co., Richland, WA (United States); Gelles, D.S. [Pacific Northwest Lab., Richland, WA (United States)

    1994-07-01T23:59:59.000Z

    Ferritic alloys are known to undergo a ductile-brittle transition as the test temperature is decreased. This inherent problem has limited their applications to reactor component materials subjected to low neutron exposures. However, the excellent resistance to void swelling exhibited by these alloys has led to choosing the materials as candidate materials for fast and fusion reactor applications. Despite the ductile-brittle transition problem, results show that the materials exhibit superior resistance to fracture under very high neutron fluences at irradiation temperatures above 380{degrees}C. Impact testing on FFTF duct sections of HT9 indicates that HT9 ducts have adequate fracture toughness at much higher temperatures for handling operations at room temperature and refueling operations.

  5. HIGH-VELOCITY LINE FORMING REGIONS IN THE TYPE Ia SUPERNOVA 2009ig

    SciTech Connect (OSTI)

    Marion, G. H.; Foley, Ryan J.; Challis, Peter; Kirshner, Robert P. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Vinko, Jozsef; Wheeler, J. Craig; Silverman, Jeffrey M. [University of Texas at Austin, 1 University Station C1400, Austin, TX 78712-0259 (United States); Hsiao, Eric Y. [Carnegie Observatories, Las Campanas Observatory, Colina El Pino, Casilla 601 (Chile); Brown, Peter J. [George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Department of Physics and Astronomy, Texas A and M University, 4242 AMU, College Station, TX 77843 (United States); Filippenko, Alexei V. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Garnavich, Peter [Department of Physics, University of Notre Dame, 225 Nieuwland Science Hall, Notre Dame, IN 46556 (United States); Landsman, Wayne B. [Adnet Systems, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Parrent, Jerod T. [Las Cumbres Observatory Global Telescope Network, Goleta, CA 93117 (United States); Pritchard, Tyler A.; Roming, Peter W. A. [Department of Astronomy and Astrophysics, Penn State University, 525 Davey Lab, University Park, PA 16802 (United States); Wang, Xiaofeng, E-mail: gmarion@cfa.harvard.edu [Physics Department and Tsinghua Center for Astrophysics (THCA), Tsinghua University, Beijing 1,00084 (China)

    2013-11-01T23:59:59.000Z

    We report measurements and analysis of high-velocity (HVF) (>20,000 km s{sup –1}) and photospheric absorption features in a series of spectra of the Type Ia supernova (SN) 2009ig obtained between –14 days and +13 days with respect to the time of maximum B-band luminosity (B-max). We identify lines of Si II, Si III, S II, Ca II, and Fe II that produce both HVF and photospheric-velocity (PVF) absorption features. SN 2009ig is unusual for the large number of lines with detectable HVF in the spectra, but the light-curve parameters correspond to a slightly overluminous but unexceptional SN Ia (M{sub B} = –19.46 mag and ?m{sub 15}(B) = 0.90 mag). Similarly, the Si II ?6355 velocity at the time of B-max is greater than 'normal' for an SN Ia, but it is not extreme (v{sub Si} = 13,400 km s{sup –1}). The –14 days and –13 days spectra clearly resolve HVF from Si II ?6355 as separate absorptions from a detached line forming region. At these very early phases, detached HVF are prevalent in all lines. From –12 days to –6 days, HVF and PVF are detected simultaneously, and the two line forming regions maintain a constant separation of about 8000 km s{sup –1}. After –6 days all absorption features are PVF. The observations of SN 2009ig provide a complete picture of the transition from HVF to PVF. Most SNe Ia show evidence for HVF from multiple lines in spectra obtained before –10 days, and we compare the spectra of SN 2009ig to observations of other SNe. We show that each of the unusual line profiles for Si II ?6355 found in early-time spectra of SNe Ia correlate to a specific phase in a common development sequence from HVF to PVF.

  6. A DETAILED KINEMATIC MAP OF CASSIOPEIA A'S OPTICAL MAIN SHELL AND OUTER HIGH-VELOCITY EJECTA

    SciTech Connect (OSTI)

    Milisavljevic, Dan [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA, 02138 (United States); Fesen, Robert A., E-mail: dmilisav@cfa.harvard.edu [6127 Wilder Lab, Department of Physics and Astronomy, Dartmouth College, Hanover, NH 03755 (United States)

    2013-08-01T23:59:59.000Z

    We present three-dimensional (3D) kinematic reconstructions of optically emitting material in the young Galactic supernova remnant Cassiopeia A (Cas A). These Doppler maps have the highest spectral and spatial resolutions of any previous survey of Cas A and represent the most complete catalog of its optically emitting material to date. We confirm that the bulk of Cas A's optically bright ejecta populate a torus-like geometry tilted approximately 30 Degree-Sign with respect to the plane of the sky with a -4000 to +6000 km s{sup -1} radial velocity asymmetry. Near-tangent viewing angle effects and an inhomogeneous surrounding circumstellar material/interstellar medium environment suggest that this geometry and velocity asymmetry may not be faithfully representative of the remnant's true 3D structure or the kinematic properties of the original explosion. The majority of the optical ejecta are arranged in several well-defined and nearly circular ring-like structures with diameters between approximately 30'' (0.5 pc) and 2' (2 pc). These ejecta rings appear to be a common phenomenon of young core-collapse remnants and may be associated with post-explosion input of energy from plumes of radioactive {sup 56}Ni-rich ejecta that rise, expand, and compress non-radioactive material. Our optical survey encompasses Cas A's faint outlying ejecta knots and exceptionally high-velocity NE and SW streams of S-rich debris often referred to as ''jets''. These outer knots, which exhibit a chemical make-up suggestive of an origin deep within the progenitor star, appear to be arranged in opposing and wide-angle outflows with opening half-angles of Almost-Equal-To 40 Degree-Sign.

  7. High strain rate metalworking with vaporizing foil actuator: Control of flyer velocity by varying input energy and foil thickness

    SciTech Connect (OSTI)

    Vivek, A., E-mail: vivek.4@osu.edu; Hansen, S. R.; Daehn, Glenn S. [Department of Materials Science and Engineering, The Ohio State University, 2041, College Road, Columbus, Ohio 43210 (United States)

    2014-07-15T23:59:59.000Z

    Electrically driven rapid vaporization of thin metallic foils can generate a high pressure which can be used to launch flyers at high velocities. Recently, vaporizing foil actuators have been applied toward a variety of impulse-based metal working operations. In order to exercise control over this useful tool, it is imperative that an understanding of the effect of characteristics of the foil actuator on its ability for mechanical impulse generation is developed. Here, foil actuators made out of 0.0508 mm, 0.0762 mm, and 0.127 mm thick AA1145 were used for launching AA2024-T3 sheets of thickness 0.508 mm toward a photonic Doppler velocimeter probe. Launch velocities ranging between 300 m/s and 1100 m/s were observed. In situ measurement of velocity, current, and voltage assisted in understanding the effect of burst current density and deposited electrical energy on average pressure and velocity with foil actuators of various thicknesses. For the pulse generator, geometry, and flyer used here, the 0.0762 mm thick foil was found to be optimal for launching flyers to high velocities over short distances. Experimenting with annealed foil actuators resulted in no change in the temporal evolution of flyer velocity as compared to foil actuators of full hard temper. A physics-based analytical model was developed and found to have reasonable agreement with experiment.

  8. STATE OF CALIFORNIA DUCT LEAKAGE TEST COMPLETELY NEW OR REPLACEMENT DUCT SYSTEM

    E-Print Network [OSTI]

    STATE OF CALIFORNIA DUCT LEAKAGE TEST ­ COMPLETELY NEW OR REPLACEMENT DUCT SYSTEM CEC- CF-6R Leakage Test ­ Completely New or Replacement Duct System (Page 1 of 3) Site Address: Enforcement Agency new or replacement duct systems in existing dwellings. For existing dwellings, a completely new

  9. High Velocity Interparticle Collisions Driven by Ultrasound Tanya Prozorov, Ruslan Prozorov, and Kenneth S. Suslick*,

    E-Print Network [OSTI]

    Suslick, Kenneth S.

    the liquid at velocities above the speed of sound.1-4 Unusual sonochemical effects are induced by these shock velocity of colliding particles approaches half the speed of sound in the liquid.4 The low melting point@uiuc.edu Ultrasonic irradiation of liquids produces transient cavitation: the formation, growth, and implosive

  10. Measurements of Smoke Characteristics in HVAC Ducts 

    E-Print Network [OSTI]

    Wolin, Steven D; Ryder, Noah L; Leprince, Frederic; Milke, James; Mowrer, Frederick; Torero, Jose L

    2001-01-01T23:59:59.000Z

    The characteristics of smoke traveling in an HVAC duct have been observed along with the response of selected duct smoke detectors. The simulated HVAC system consists of a 9 m long duct, 0.45 m in diameter. An exhaust fan is placed at one end...

  11. Energetic neutral atoms as the explanation for the high velocity hydrogen around HD 209458b

    E-Print Network [OSTI]

    M. Holmström; A. Ekenbäck; F. Selsis; T. Penz; H. Lammer; P. Wurz

    2008-02-20T23:59:59.000Z

    Absorption in the stellar Lyman-$\\alpha$ (Ly-$\\alpha$) line observed during the transit of the extrasolar planet HD 209458b reveals high velocity atomic hydrogen at great distances from the planet. This has been interpreted as hydrogen atoms escaping from the exosphere of the planet, possibly undergoing hydrodynamic blow-off, being accelerated by stellar radiation pressure. However, around solar system planets the production of energetic neutral atoms from charge exchange between solar wind protons and neutral hydrogen from the exospheres has been observed, and should also occur at extrasolar planets. Here we show that the measured transit-associated Ly-$\\alpha$ absorption can be explained by the interaction between the exosphere of HD 209458b and the stellar wind, and that radiation pressure alone cannot explain the observation. This is the first observation of energetic neutral atoms outside the solar system. Since the stellar wind protons are the source of the observed energetic neutral atoms, this provides a completely new method of probing stellar wind conditions, and our model suggests a slow and hot stellar wind near HD 209458b at the time of the observation.

  12. Searching for Dark Matter Annihilation in the Smith High-Velocity Cloud

    E-Print Network [OSTI]

    Alex Drlica-Wagner; German A. Gomez-Vargas; John W. Hewitt; Tim Linden; Luigi Tibaldo

    2014-06-30T23:59:59.000Z

    Recent observations suggest that some high-velocity clouds may be confined by massive dark matter halos. In particular, the proximity and proposed dark matter content of the Smith Cloud make it a tempting target for the indirect detection of dark matter annihilation. We argue that the Smith Cloud may be a better target than some Milky Way dwarf spheroidal satellite galaxies and use gamma-ray observations from the Fermi Large Area Telescope to search for a dark matter annihilation signal. No significant gamma-ray excess is found coincident with the Smith Cloud, and we set strong limits on the dark matter annihilation cross section assuming a spatially-extended dark matter profile consistent with dynamical modeling of the Smith Cloud. Notably, these limits exclude the canonical thermal relic cross section ($\\sim 3\\times10^{-26}{\\rm cm}^{3}{\\rm s}^{-1}$) for dark matter masses $\\lesssim 30$ GeV annihilating via the $b \\bar b$ or $\\tau^{+}\\tau^{-}$ channels for certain assumptions of the dark matter density profile; however, uncertainties in the dark matter content of the Smith Cloud may significantly weaken these constraints.

  13. Calculation and measurement of a neutral air flow velocity impacting a high voltage capacitor with asymmetrical electrodes

    SciTech Connect (OSTI)

    Malík, M., E-mail: michal.malik@tul.cz; Primas, J.; Kopecký, V.; Svoboda, M. [Faculty of Mechatronics, Informatics and Interdisciplinary Studies, Technical University of Liberec, Liberec, 461 17 (Czech Republic)] [Faculty of Mechatronics, Informatics and Interdisciplinary Studies, Technical University of Liberec, Liberec, 461 17 (Czech Republic)

    2014-01-15T23:59:59.000Z

    This paper deals with the effects surrounding phenomenon of a mechanical force generated on a high voltage asymmetrical capacitor (the so called Biefeld-Brown effect). A method to measure this force is described and a formula to calculate its value is also given. Based on this the authors derive a formula characterising the neutral air flow velocity impacting an asymmetrical capacitor connected to high voltage. This air flow under normal circumstances lessens the generated force. In the following part this velocity is measured using Particle Image Velocimetry measuring technique and the results of the theoretically calculated velocity and the experimentally measured value are compared. The authors found a good agreement between the results of both approaches.

  14. Particle deposition in ventilation ducts

    E-Print Network [OSTI]

    Sippola, Mark R.

    2002-01-01T23:59:59.000Z

    and An Evaluation of Thermophoretic Deposition Rates C.1of estimated thermophoretic deposition velocities, v th+ ,of estimated thermophoretic deposition velocities, v th+ ,

  15. EROSIVE WEAR OF DUCTILE METALS BY A PARTICLE-LADEN HIGH-VELOCITY LIQUID-JET

    E-Print Network [OSTI]

    Li, Simon Ka-Keung

    2014-01-01T23:59:59.000Z

    of magnitude larger than by a coal slurry for erosion onlyand 1018 mild steel by coal slurry. Effect of velocity andvariation on erosion by coal slurry. Effect of material

  16. Research Results from A Few Alternate Methods of Interior Duct Systems in Factory Built Housing Located In the Hot Humid Climate

    E-Print Network [OSTI]

    Moyer, N.; Stroer, D.; Hoak, D.; McIlvaine, J.; Chandra, S.

    interior duct systems. In 2006, work began on a duct system design that would locate the entire length of duct work within the air and thermal barriers of the envelope. One of these designs incorporated a high-side supply register that connects...

  17. An all-sky study of compact, isolated high-velocity clouds

    E-Print Network [OSTI]

    V. de Heij; R. Braun; W. B. Burton

    2002-06-18T23:59:59.000Z

    We combine the catalogs of compact high-velocity HI clouds extracted from the LDS and HIPASS surveys and analyze the all-sky properties of the ensemble. Five principal observables are defined for the CHVC population: (1) the spatial deployment of the objects on the sky, (2) the kinematic distribution, (3) the number distribution of observed HI column densities, (4) the number distribution of angular sizes, and (5) the number distribution of HI linewidth. Two classes of models are considered to reproduce the observed properties. The agreement of models with the data is judged by extracting these same observables from simulations, in a manner consistent with the sensitivities of the observations and explicitly taking account of Galactic obscuration. We show that models in which the CHVCs are the HI counterparts of dark-matter halos evolving in the Local Group potential provide a good match to the observables. The best-fitting populations have a maximum HI mass of 10^7 M_Sun a power-law slope of the HI mass distribution in the range -1.7 to -1.8, and a Gaussian dispersion for their spatial distributions of between 150 and 200 kpc centered on both the Milky Way and M31. Given its greater mean distance, only a small fraction of the M31 sub-population is predicted to have been detected in present surveys. An empirical model for an extended Galactic halo distribution for the CHVCs is also considered. While reproducing some aspects of the population, this class of models does not account for some key systematic features of the population.

  18. THE SMITH CLOUD: HIGH-VELOCITY ACCRETION AND DARK MATTER CONFINEMENT

    SciTech Connect (OSTI)

    Nichols, M.; Bland-Hawthorn, J., E-mail: m.nichols@physics.usyd.edu.a [Sydney Institute for Astronomy, School of Physics, University of Sydney, NSW 2006 (Australia)

    2009-12-20T23:59:59.000Z

    The Smith Cloud is a massive system of metal-poor neutral and ionized gas (M{sub gas} approx> 2 x 10{sup 6} M{sub sun}) that is presently moving at high velocity (V{sub GSR}approx 300 km s{sup -1}) with respect to the Galaxy at a distance of 12 kpc from the Sun. The kinematics of the cloud's cometary tail indicates that the gas is in the process of accretion onto the Galaxy, as first discussed by Lockman et al. Here, we re-investigate the cloud's orbit by considering the possibility that the cloud is confined by a dark matter halo. This is required for the cloud to survive its passage through the Galactic corona. We consider three possible models for the dark matter halo (Navarro-Frenk-White (NFW), Einasto, and Burkert) including the effects of tidal disruption and ram pressure stripping during the cloud's infall onto and passage through the Galactic disk. For the NFW and Einasto dark matter models, we are able to determine reasonable initial conditions for the Smith Cloud, although this is only marginally possible with the Burkert model. For all three models, the progenitor had an initial (gas+dark matter) mass that was an order-of-magnitude higher than inferred today. In agreement with Lockman et al., the cloud appears to have punched through the disk approx70 Myr ago. For our most successful models, the baryon-to-dark matter ratio is fairly constant during an orbital period but drops by a factor of 2-5 after transiting the disk. The cloud appears to have only marginally survived its transit and is unlikely to retain its integrity during the next transit approx 30 Myr from now.

  19. Feasibility and preliminary design study for a high velocity, low density wind tunnel utilizing the thermal creep effect

    E-Print Network [OSTI]

    Stephen, Alton Lee

    1968-01-01T23:59:59.000Z

    Average molecular velocity Cartesian length co-ordinate Thermal accomodation co-efficient Constant used in Appendix I Element of volume in velocity space Angular displacement Viscosity co-efficient Gas density cm cm/sec cm/sec cm/sec cm... on spheres in a rarefied gas as a means of making correc- tions to the results of Millikan's oil drop experiment. 4 Sanger's work was followed by a paper in which Tsien out- lined the field of low density, high speed gas dynamics. In this work, Tsien used...

  20. Building America Webinar: High Performance Space Conditioning...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    II - Design Options for Locating Ducts within Conditioned Space Building America Webinar: High Performance Space Conditioning Systems, Part II - Design Options for Locating Ducts...

  1. HAARP-Induced Ionospheric Ducts

    SciTech Connect (OSTI)

    Milikh, Gennady; Vartanyan, Aram [University of Maryland, College Park, MD, 20742 (United States)

    2011-01-04T23:59:59.000Z

    It is well known that strong electron heating by a powerful HF-facility can lead to the formation of electron and ion density perturbations that stretch along the magnetic field line. Those density perturbations can serve as ducts for ELF waves, both of natural and artificial origin. This paper presents observations of the plasma density perturbations caused by the HF-heating of the ionosphere by the HAARP facility. The low orbit satellite DEMETER was used as a diagnostic tool to measure the electron and ion temperature and density along the satellite orbit overflying close to the magnetic zenith of the HF-heater. Those observations will be then checked against the theoretical model of duct formation due to HF-heating of the ionosphere. The model is based on the modified SAMI2 code, and is validated by comparison with well documented experiments.

  2. Modeling particle loss in ventilation ducts

    SciTech Connect (OSTI)

    Sippola, Mark R.; Nazaroff, William W.

    2003-04-01T23:59:59.000Z

    Empirical equations were developed and applied to predict losses of 0.01-100 {micro}m airborne particles making a single pass through 120 different ventilation duct runs typical of those found in mid-sized office buildings. For all duct runs, losses were negligible for submicron particles and nearly complete for particles larger than 50 {micro}m. The 50th percentile cut-point diameters were 15 {micro}m in supply runs and 25 {micro}m in return runs. Losses in supply duct runs were higher than in return duct runs, mostly because internal insulation was present in portions of supply duct runs, but absent from return duct runs. Single-pass equations for particle loss in duct runs were combined with models for predicting ventilation system filtration efficiency and particle deposition to indoor surfaces to evaluate the fates of particles of indoor and outdoor origin in an archetypal mechanically ventilated building. Results suggest that duct losses are a minor influence for determining indoor concentrations for most particle sizes. Losses in ducts were of a comparable magnitude to indoor surface losses for most particle sizes. For outdoor air drawn into an unfiltered ventilation system, most particles smaller than 1 {micro}m are exhausted from the building. Large particles deposit within the building, mostly in supply ducts or on indoor surfaces. When filters are present, most particles are either filtered or exhausted. The fates of particles generated indoors follow similar trends as outdoor particles drawn into the building.

  3. Generator stator core vent duct spacer posts

    DOE Patents [OSTI]

    Griffith, John Wesley (Schenectady, NY); Tong, Wei (Clifton Park, NY)

    2003-06-24T23:59:59.000Z

    Generator stator cores are constructed by stacking many layers of magnetic laminations. Ventilation ducts may be inserted between these layers by inserting spacers into the core stack. The ventilation ducts allow for the passage of cooling gas through the core during operation. The spacers or spacer posts are positioned between groups of the magnetic laminations to define the ventilation ducts. The spacer posts are secured with longitudinal axes thereof substantially parallel to the core axis. With this structure, core tightness can be assured while maximizing ventilation duct cross section for gas flow and minimizing magnetic loss in the spacers.

  4. High-pressure sound velocities and elasticity of aluminous MgSiO3 perovskite to 45 GPa: Implications for lateral heterogeneity in Earth's

    E-Print Network [OSTI]

    Jackson, Jennifer M.

    High-pressure sound velocities and elasticity of aluminous MgSiO3 perovskite to 45 GPa lateral variations of seismic wave speeds in Earth's lower mantle are due at least in part to a chemical, J. M., J. Zhang, J. Shu, S. V. Sinogeikin, and J. D. Bass (2005), High-pressure sound velocities

  5. On the Fundamental Unsteady Fluid Dynamics of Shock-Induced Flows through Ducts

    E-Print Network [OSTI]

    Mendoza, Nicole Renee

    2013-04-29T23:59:59.000Z

    Unsteady shock wave propagation through ducts has many applications, ranging from blast wave shelter design to advanced high-speed propulsion systems. The research objective of this study was improved fundamental understanding of the transient flow...

  6. Measure Guideline: Sealing and Insulating of Ducts in Existing Homes

    SciTech Connect (OSTI)

    Aldrich, R.; Puttagunta, S.

    2011-12-01T23:59:59.000Z

    This document begins with a discussion on potential cost and performance benefits of duct sealing and insulating. It continues with a review of typical duct materials and components and the overall procedures for assessing and improving the duct system.

  7. Compression effects on pressure loss in flexible HVAC ducts

    E-Print Network [OSTI]

    Abushakra, Bass; Walker, Iain S.; Sherman, Max H.

    2002-01-01T23:59:59.000Z

    to Determine Flow Resistance of HVAC Air Ducts and Fittings.Pressure Loss in Flexible HVAC Ducts Bass Abushakra, Ph.D.to Determine Flow Resistance of HVAC Air Ducts and Fittings.

  8. Geometry Effects on Multipole Components and Beam Optics in High-Velocity Multi-Spoke Cavities

    SciTech Connect (OSTI)

    Hopper, Christopher S. [ODU, JLAB; Deitrick, Kirsten E. [ODU, JLAB; Delayen, Jean R. [ODU, JLAB

    2013-12-01T23:59:59.000Z

    Velocity-of-light, multi-spoke cavities are being proposed to accelerate electrons in a compact light-source. There are strict requirements on the beam quality which require that the linac have only small non-uniformities in the accelerating field. Beam dynamics simulations have uncovered varying levels of focusing and defocusing in the proposed cavities, which is dependent on the geometry of the spoke in the vicinity of the beam path. Here we present results for the influence different spoke geometries have on the multipole components of the accelerating field and how these components, in turn, impact the simulated beam properties.

  9. Global well-posedness for the compressible Navier-Stokes equations with the highly oscillating initial velocity

    E-Print Network [OSTI]

    Qionglei Chen; Changxing Miao; Zhifei Zhang

    2009-08-02T23:59:59.000Z

    Cannone \\cite{Cannone} proved the global well-posedness of the incompressible Navier-Stokes equations for a class of highly oscillating data. In this paper, we prove the global well-posedness for the compressible Navier-Stokes equations in the critical functional framework with the initial data close to a stable equilibrium. Especially, this result allows us to construct global solutions for the highly oscillating initial velocity. The proof relies on a new estimate for the hyperbolic/parabolic system with convection terms.

  10. A Detailed Kinematic Map of Cassiopeia A's Optical Main Shell and Outer High-Velocity Ejecta

    E-Print Network [OSTI]

    Milisavljevic, Dan

    2013-01-01T23:59:59.000Z

    We present three-dimensional kinematic reconstructions of optically emitting material in the young Galactic supernova remnant Cassiopeia A (Cas A). These Doppler maps have the highest spectral and spatial resolutions of any previous survey of Cas A and represent the most complete catalog of its optically emitting material to date. We confirm that the bulk of Cas A's optically bright ejecta populate a torus-like geometry tilted approximately 30 degrees with respect to the plane of the sky with a -4000 to +6000 km/s radial velocity asymmetry. Near-tangent viewing angle effects and an inhomogeneous surrounding CSM/ISM environment suggest that this geometry and velocity asymmetry may not be faithfully representative of the remnant's true 3D structure or the kinematic properties of the original explosion. The majority of the optical ejecta are arranged in several well-defined and nearly circular ring-like structures with diameters between approximately 30 arcsec (0.5 pc) and 2 arcmin (2 pc). These ejecta rings app...

  11. Double-duct liquid metal magnetohydrodynamic engine

    DOE Patents [OSTI]

    Haaland, Carsten M. (Oak Ridge, TN)

    1995-01-01T23:59:59.000Z

    An internal combustion, liquid metal (LM) magnetohydrodynamic (MHD) engine and an alternating current (AC) magnetohydrodynamic generator, are used in combination to provide useful AC electric energy output. The engine design has-four pistons and a double duct configuration, with each duct containing sodium potassium liquid metal confined between free pistons located at either end of the duct. The liquid metal is forced to flow back and forth in the duct by the movement of the pistons, which are alternatively driven by an internal combustion process. In the MHD generator, the two LM-MHD ducts pass in close proximity through a Hartmann duct with output transformer. AC power is produced by operating the engine with the liquid metal in the two generator ducts always flowing in counter directions. The amount of liquid metal maintained in the ducts may be varied. This provides a variable stroke length for the pistons. The engine/generator provides variable AC power at variable frequencies that correspond to the power demands of the vehicular propulsion. Also the engine should maintain nearly constant efficiency throughout the range of power usage. Automobiles and trucks could be powered by the invention, with no transmission or power converter devices being required.

  12. Double-duct liquid metal magnetohydrodynamic engine

    DOE Patents [OSTI]

    Haaland, Carsten M. (Oak Ridge, TN)

    1997-01-01T23:59:59.000Z

    An internal combustion, liquid metal (LM) magnetohydrodynamic (MHD) engine and an alternating current (AC) magnetohydrodynamic generator, are used in combination to provide useful AC electric energy output. The engine design has four pistons and a double duct configuration, with each duct containing sodium potassium liquid metal confined between free pistons located at either end of the duct. The liquid metal is forced to flow back and forth in the duct by the movement of the pistons, which are alternatively driven by an internal combustion process. In the MHD generator, the two LM-MHD ducts pass in close proximity through a Hartmann duct with output transformer. AC power is produced by operating the engine with the liquid metal in the two generator ducts always flowing in counter directions. The amount of liquid metal maintained in the ducts may be varied. This provides a variable stroke length for the pistons. The engine/generator provides variable AC power at variable frequencies that correspond to the power demands of the vehicular propulsion. Also the engine should maintain nearly constant efficiency throughout the range of power usage. Automobiles and trucks could be powered by the invention, with no transmission or power converter devices being required.

  13. A Review of Thermal Acoustical and Special Project Requirements Data in Designing a Duct System

    E-Print Network [OSTI]

    Lebens, A. F.

    1986-01-01T23:59:59.000Z

    less than acceptable environment for occupants could occur. AIR LEAKAGE Probably the most neglected design criteria for duct work is air leakage. Testing by SMACNA (HVAC Air Duct Leakage Test Manual. First Edition, August. 1985), and TIM (Thermal... 48 48 48 Appendix A of the SMACNA HVAC Air Duct Leakage Test Manual gives leakage as a percent of flow in a system by Leakage Class, fan CFM, and static pressure. The leakage in a 1" static pressure system can be as high as 24 percent in Leakage...

  14. Seismic Technology Adapted to Analyzing and Developing Geothermal Systems Below Surface-Exposed High-Velocity Rocks Final Report

    SciTech Connect (OSTI)

    Hardage, Bob A; DeAngelo, Michael V; Ermolaeva, Elena; Hardage, Bob A; Remington, Randy; Sava, Diana; Wagner, Donald; Wei, Shuijion

    2013-02-28T23:59:59.000Z

    The objective of our research was to develop and demonstrate seismic data-acquisition and data-processing technologies that allow geothermal prospects below high-velocity rock outcrops to be evaluated. To do this, we acquired a 3-component seismic test line across an area of exposed high-velocity rocks in Brewster County, Texas, where there is high heat flow and surface conditions mimic those found at numerous geothermal prospects. Seismic contractors have not succeeded in creating good-quality seismic data in this area for companies who have acquired data for oil and gas exploitation purposes. Our test profile traversed an area where high-velocity rocks and low-velocity sediment were exposed on the surface in alternating patterns that repeated along the test line. We verified that these surface conditions cause non-ending reverberations of Love waves, Rayleigh waves, and shallow critical refractions to travel across the earth surface between the boundaries of the fast-velocity and slow-velocity material exposed on the surface. These reverberating surface waves form the high level of noise in this area that does not allow reflections from deep interfaces to be seen and utilized. Our data-acquisition method of deploying a box array of closely spaced geophones allowed us to recognize and evaluate these surface-wave noise modes regardless of the azimuth direction to the surface anomaly that backscattered the waves and caused them to return to the test-line profile. With this knowledge of the surface-wave noise, we were able to process these test-line data to create P-P and SH-SH images that were superior to those produced by a skilled seismic data-processing contractor. Compared to the P-P data acquired along the test line, the SH-SH data provided a better detection of faults and could be used to trace these faults upward to the boundaries of exposed surface rocks. We expanded our comparison of the relative value of S-wave and P-wave seismic data for geothermal applications by inserting into this report a small part of the interpretation we have done with 3C3D data across Wister geothermal field in the Imperial Valley of California. This interpretation shows that P-SV data reveal faults (and by inference, also fractures) that cannot be easily, or confidently, seen with P-P data, and that the combination of P-P and P-SV data allows VP/VS velocity ratios to be estimated across a targeted reservoir interval to show where an interval has more sandstone (the preferred reservoir facies). The conclusion reached from this investigation is that S-wave seismic technology can be invaluable to geothermal operators. Thus we developed a strong interest in understanding the direct-S modes produced by vertical-force sources, particularly vertical vibrators, because if it can be demonstrated that direct-S modes produced by vertical-force sources can be used as effectively as the direct-S modes produced by horizontal-force sources, geothermal operators can acquire direct-S data across many more prospect areas than can be done with horizontal-force sources, which presently are limited to horizontal vibrators. We include some of our preliminary work in evaluating direct-S modes produced by vertical-force sources.

  15. Computational Fluid Dynamics Analysis of Flexible Duct Junction Box Design

    SciTech Connect (OSTI)

    Beach, R.; Prahl, D.; Lange, R.

    2013-12-01T23:59:59.000Z

    IBACOS explored the relationships between pressure and physical configurations of flexible duct junction boxes by using computational fluid dynamics (CFD) simulations to predict individual box parameters and total system pressure, thereby ensuring improved HVAC performance. Current Air Conditioning Contractors of America (ACCA) guidance (Group 11, Appendix 3, ACCA Manual D, Rutkowski 2009) allows for unconstrained variation in the number of takeoffs, box sizes, and takeoff locations. The only variables currently used in selecting an equivalent length (EL) are velocity of air in the duct and friction rate, given the first takeoff is located at least twice its diameter away from the inlet. This condition does not account for other factors impacting pressure loss across these types of fittings. For each simulation, the IBACOS team converted pressure loss within a box to an EL to compare variation in ACCA Manual D guidance to the simulated variation. IBACOS chose cases to represent flows reasonably correlating to flows typically encountered in the field and analyzed differences in total pressure due to increases in number and location of takeoffs, box dimensions, and velocity of air, and whether an entrance fitting is included. The team also calculated additional balancing losses for all cases due to discrepancies between intended outlet flows and natural flow splits created by the fitting. In certain asymmetrical cases, the balancing losses were significantly higher than symmetrical cases where the natural splits were close to the targets. Thus, IBACOS has shown additional design constraints that can ensure better system performance.

  16. A CATALOG OF ULTRA-COMPACT HIGH VELOCITY CLOUDS FROM THE ALFALFA SURVEY: LOCAL GROUP GALAXY CANDIDATES?

    SciTech Connect (OSTI)

    Adams, Elizabeth A. K.; Giovanelli, Riccardo; Haynes, Martha P., E-mail: betsey@astro.cornell.edu, E-mail: riccardo@astro.cornell.edu, E-mail: haynes@astro.cornell.edu [Center for Radiophysics and Space Research, Space Sciences Building, Cornell University, Ithaca, NY 14853 (United States)

    2013-05-01T23:59:59.000Z

    We present a catalog of 59 ultra-compact high velocity clouds (UCHVCs) extracted from the 40% complete ALFALFA HI-line survey. The ALFALFA UCHVCs have median flux densities of 1.34 Jy km s{sup -1}, median angular diameters of 10', and median velocity widths of 23 km s{sup -1}. We show that the full UCHVC population cannot easily be associated with known populations of high velocity clouds. Of the 59 clouds presented here, only 11 are also present in the compact cloud catalog extracted from the commensal GALFA-HI survey, demonstrating the utility of this separate dataset and analysis. Based on their sky distribution and observed properties, we infer that the ALFALFA UCHVCs are consistent with the hypothesis that they may be very low mass galaxies within the Local Volume. In that case, most of their baryons would be in the form of gas, and because of their low stellar content, they remain unidentified by extant optical surveys. At distances of {approx}1 Mpc, the UCHVCs have neutral hydrogen (H I) masses of {approx}10{sup 5}-10{sup 6} M{sub Sun }, H I diameters of {approx}2-3 kpc, and indicative dynamical masses within the H I extent of {approx}10{sup 7}-10{sup 8} M{sub Sun }, similar to the Local Group ultra-faint dwarf Leo T. The recent ALFALFA discovery of the star-forming, metal-poor, low mass galaxy Leo P demonstrates that this hypothesis is true in at least one case. In the case of the individual UCHVCs presented here, confirmation of their extragalactic nature will require further work, such as the identification of an optical counterpart to constrain their distance.

  17. HIGH VELOCITY PRECESSING JETS FROM THE WATER FOUNTAIN IRAS 18286-0959 REVEALED BY VERY LONG BASELINE ARRAY OBSERVATIONS

    SciTech Connect (OSTI)

    Yung, Bosco H. K.; Nakashima, Jun-ichi; Kwok, Sun [Department of Physics, University of Hong Kong, Pokfulam Rd., Hong Kong (Hong Kong); Imai, Hiroshi [Graduate School of Science and Engineering, Kagoshima University, Kagoshima 890-0065 (Japan); Deguchi, Shuji [Nobeyama Radio Observatory, National Astronomical Observatory of Japan, Minamimaki, Minamisaku, Nagano 384-1305 (Japan); Diamond, Philip J. [Jodrell Bank Centre for Astrophysics, Alan Turing Building, University of Manchester, Manchester M13 9PL (United Kingdom)

    2011-11-10T23:59:59.000Z

    We report the results of multi-epoch Very Long Baseline Array observations of the 22.2 GHz H{sub 2}O maser emission associated with the 'water fountain' IRAS 18286-0959. We suggest that this object is the second example of a highly collimated bipolar precessing outflow traced by H{sub 2}O maser emission, the other is W 43A. The detected H{sub 2}O emission peaks are distributed over a velocity range from -50 km s{sup -1} to 150 km s{sup -1}. The spatial distribution of over 70% of the identified maser features is found to be highly collimated along a spiral jet (jet 1) extended southeast to northwest; the remaining features appear to trace another spiral jet (jet 2) with a different orientation. The two jets form a 'double-helix' pattern which lies across {approx}200 mas. The maser distribution is reasonably fit by a model consisting of two bipolar precessing jets. The three-dimensional velocities of jet 1 and jet 2 are derived to be 138 km s{sup -1} and 99 km s{sup -1}, respectively. The precession period of jet 1 is about 56 years. For jet 2, three possible models are tested and they give different values for the kinematic parameters. We propose that the appearance of two jets is the result of a single driving source with significant proper motion.

  18. GALACTIC ALL-SKY SURVEY HIGH-VELOCITY CLOUDS IN THE REGION OF THE MAGELLANIC LEADING ARM

    SciTech Connect (OSTI)

    For, Bi-Qing; Staveley-Smith, Lister [International Centre for Radio Astronomy Research, University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009 (Australia)] [International Centre for Radio Astronomy Research, University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009 (Australia); McClure-Griffiths, N. M., E-mail: biqing.for@uwa.edu.au [Australia Telescope National Facility, CSIRO Astronomy and Space Science, PO Box 76, Epping, NSW 1710 (Australia)

    2013-02-10T23:59:59.000Z

    We present a catalog of high-velocity clouds in the region of the Magellanic Leading Arm. The catalog is based on neutral hydrogen (H I) observations from the Parkes Galactic All-Sky Survey. Excellent spectral resolution allows clouds with narrow-line components to be resolved. The total number of detected clouds is 419. We describe the method of cataloging and present the basic parameters of the clouds. We discuss the general distribution of the high-velocity clouds and classify the clouds based on their morphological type. The presence of a significant number of head-tail clouds and their distribution in the region is discussed in the context of Magellanic System simulations. We suggest that ram-pressure stripping is a more important factor than tidal forces for the morphology and formation of the Magellanic Leading Arm and that different environmental conditions might explain the morphological difference between the Magellanic Leading Arm and Magellanic Stream. We also discuss a newly identified population of clouds that forms the LA IV and a new diffuse bridge-like feature connecting the LA II and III complexes.

  19. Particle deposition in ventilation ducts

    E-Print Network [OSTI]

    Sippola, Mark R.

    2002-01-01T23:59:59.000Z

    were observed to lead to resuspension of particles in thethe nozzles may lead to resuspension of deposited particles.resuspension, the decreased response to turbulent velocity fluctuations of the very large particles should lead

  20. A Comparison of Simulation Capabilities for Ducts

    SciTech Connect (OSTI)

    Miller, William A [ORNL; Smith, Matt K [ORNL; Gu, Lixing [Florida Solar Energy Center (FSEC); New, Joshua Ryan [ORNL

    2014-11-01T23:59:59.000Z

    Typically, the cheapest way to install a central air conditioning system in residential buildings is to place the ductwork in the attic. Energy losses due to duct-attic interactions can be great, but current whole-house models are unable to capture the dynamic multi-mode physics of the interactions. The building industry is notoriously fragmented and unable to devote adequate research resources to solve this problem. Builders are going to continue to put ducts in the attic because floor space is too expensive to closet them within living space, and there are both construction and aesthetic issues with other approaches such as dropped ceilings. Thus, there is a substantial need to publicly document duct losses and the cost of energy used by ducts in attics so that practitioners, builders, homeowners and state and federal code officials can make informed decisions leading to changes in new construction and additional retrofit actions. Thus, the goal of this study is to conduct a comparison of AtticSim and EnergyPlus simulation algorithms to identify specific features for potential inclusion in EnergyPlus that would allow higher-fidelity modeling of HVAC operation and duct transport of conditioned air. It is anticipated that the resulting analysis from these simulation tools will inform energy decisions relating to the role of ducts in future building energy codes and standards.

  1. Preliminary results from In-Duct Scrubbing Pilot Study testing

    SciTech Connect (OSTI)

    Samuel, E.A.; Murphy, K.R.; Pennline, H.W.

    1987-01-01T23:59:59.000Z

    A low-cost, moderate-removal-efficiency, flue gas desulfurization (FGD) technology was selected by the Department of Energy for demonstration in its Acid Rain Precursor Control Technology Initiative. The process, identified as In-Duct Scrubbing (IDS), applied rotary atomizer techniques developed for lime-based spray dryer FGD while utilizing existing flue gas ductwork and particulate collectors. In-Duct Scrubbing technology is anticipated to result in a dry desulfurization process with a moderate removal efficiency (50% or greater) for high-sulfur coal-fired boilers. The critical elements for successful application are (i) adequate mixing of sorbent with the flue gas for efficient reactant contact, (ii) sufficient residence time to produce a non-wetting product, and (iii) appropriate ductwork cross-sectional area to prevent deposition of wet reaction products before particle drying is complete. This paper presents the IDS technology and the status of a jointly sponsored In-Duct Scrubbing Pilot Study that is being tested at the Muskingum River Plant of the American Electric Power System.

  2. Duct injection technology prototype development: Nozzle development Subtask 4. 1, Atomizer specifications for duct injection technology

    SciTech Connect (OSTI)

    Not Available

    1992-02-01T23:59:59.000Z

    Babcock Wilcox has conducted a program to identify atomizers appropriate for successful in-duct injection of humidification water and lime slurries. The purpose of this program was to identify and quantify atomizer spray and performance criteria that affect the operations and reliability of the in-duct SO{sub 2} removal process, and compare commercially available atomizers to these criteria.

  3. Hydrodynamic Modeling, Optimization and Performance Assessment for Ducted and Non-ducted Tidal Turbines

    E-Print Network [OSTI]

    Pedersen, Tom

    Turbines by Michael Robert Shives B.Eng., Carleton University, 2008 A Dissertation Submitted in Partial Hydrodynamic Modeling, Optimization and Performance Assessment for Ducted and Non-ducted Tidal Turbines) #12;iii ABSTRACT This thesis examines methods for designing and analyzing kinetic turbines based

  4. Hydrodynamic Modeling, Optimization and Performance Assessment for Ducted and Non-ducted Tidal Turbines

    E-Print Network [OSTI]

    Victoria, University of

    Turbines by Michael Robert Shives B.Eng., Carleton University, 2008 A Thesis Submitted in Partial Hydrodynamic Modeling, Optimization and Performance Assessment for Ducted and Non-ducted Tidal Turbines examines methods for designing and analyzing kinetic turbines based on blade element momentum (BEM) theory

  5. A compact single-camera system for high-speed, simultaneous 3-D velocity and temperature measurements.

    SciTech Connect (OSTI)

    Lu, Louise [University of Michigan, Ann Arbor, MI; Sick, Volker [University of Michigan, Ann Arbor, MI; Frank, Jonathan H.

    2013-09-01T23:59:59.000Z

    The University of Michigan and Sandia National Laboratories collaborated on the initial development of a compact single-camera approach for simultaneously measuring 3-D gasphase velocity and temperature fields at high frame rates. A compact diagnostic tool is desired to enable investigations of flows with limited optical access, such as near-wall flows in an internal combustion engine. These in-cylinder flows play a crucial role in improving engine performance. Thermographic phosphors were proposed as flow and temperature tracers to extend the capabilities of a novel, compact 3D velocimetry diagnostic to include high-speed thermometry. Ratiometric measurements were performed using two spectral bands of laser-induced phosphorescence emission from BaMg2Al10O17:Eu (BAM) phosphors in a heated air flow to determine the optimal optical configuration for accurate temperature measurements. The originally planned multi-year research project ended prematurely after the first year due to the Sandia-sponsored student leaving the research group at the University of Michigan.

  6. Compact High Velocity Clouds

    E-Print Network [OSTI]

    Robert Braun

    2000-09-01T23:59:59.000Z

    We summarize the observed properties of the CHVC population, which provide strong evidence for source distances in the range 200-1000 kpc. At these distances, the population corresponds to strongly dark-matter dominated sub-dwarf galaxies still accreting onto the more massive Local Group systems. Recent searches for faint associated stellar populations have revealed red-giant candidates for which follow-up spectroscopy is scheduled. A sensitive HI survey for CHVC counterparts in the NGC 628 galaxy group has allowed tentative detection of 40 candidates, for which confirming observations have been approved. Many open issues should be resolved by observational programs within the coming years.

  7. High velocity impact fracture

    E-Print Network [OSTI]

    Teng, Xiaoqing

    2005-01-01T23:59:59.000Z

    An in-depth understanding of dynamic ductile fracture is one of the most important steps to improve the survivability of critical structures such as the lost Twin Towers. In the present thesis, the macroscopic fracture ...

  8. Evaluation of PEGIT duct connection system

    SciTech Connect (OSTI)

    Walker, Iain S.; Brenner, Douglas E.; Sherman, Max H.; Dickerhoff, Darryl J.

    2003-08-01T23:59:59.000Z

    Most air duct system components are assembled in the field and are mechanically fastened by sheet metal screws (for sheet metal-to-sheet metal) or by drawbands (for flex duct-to-sheet metal). Air sealing is separate from this mechanical fastening and is usually achieved using tape or mastic products after mechanical fastening. Field observations have shown that mechanical fastening rarely meets code or manufacturers requirements and that sealing procedures are similarly inconsistent. To address these problems, Proctor Engineering Group (PEG) is developing a system of joining ducts (called PEGIT) that combines the mechanical fastening and sealing into a single self-contained procedure. The PEGIT system uses a shaped flexible seal between specially designed sheet metal duct fittings to both seal and fasten duct sections together. Figure 1 shows the inner duct fitting complete with rubber seal. This seal provides the air seal for the completed fitting and is shaped to allow the inner and outer fittings to slide together, and then to lock the fittings in place. The illustration in Figure 2 shows the approximate cross section of the rubber seal that shows how the seal has a lip that is angled backwards. This angled lip allows the joint to be pushed together by folding flat but then its long axis makes it stiff in the pulling apart direction. This study was undertaken to assist PEG in some of the design aspects of this system and to test the performance of the PEGIT system. This study was carried out in three phases. The initial phase evaluated the performance of a preliminary seal design for the PEGIT system. After the first phase, the seal was redesigned and this new seal was evaluated in the second phase of testing. The third phase performed more detailed testing of the second seal design to optimize the production tolerances of the sheet metal fittings. This report summarizes our findings from the first two phases and provides details about the third phase of testing.

  9. Fundamental investigation of duct/ESP phenomena

    SciTech Connect (OSTI)

    Brown, C.A. (Radian Corp., Austin, TX (United States)); Durham, M.D. (ADA Technologies, Inc., Englewood, CO (United States)); Sowa, W.A. (California Univ., Irvine, CA (United States). Combustion Lab.); Himes, R.M. (Fossil Energy Research Corp., Laguna Hills, CA (United States)); Mahaffey, W.A. (CHAM of North America, Inc., Huntsville, AL (United States))

    1991-10-21T23:59:59.000Z

    Radian Corporation was contracted to investigate duct injection and ESP phenomena in a 1.7 MW pilot plant constructed for this test program. This study was an attempt to resolve problems found in previous studies and answer remaining questions for the technology using an approach which concentrates on the fundamental mechanisms of the process. The goal of the study was to obtain a better understanding of the basic physical and chemical phenomena that control: (1) the desulfurization of flue gas by calcium-based reagent, and (2) the coupling of an existing ESP particulate collection device to the duct injection process. Process economics are being studied by others. (VC)

  10. Tips: Air Ducts | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page onYouTube YouTube Note: Since the.pdfBreakingMayDepartmentTest for PumpingThe| Department ofAir Ducts Tips: Air Ducts July

  11. The Effects of Geometry on Flexible Duct CFD Simulations

    E-Print Network [OSTI]

    Ugursal, A.; Culp, C.

    Flexible ducts have been widely used in the building industry due to low cost and ease of installation. These ducts can be installed in a wide range of configurations, which creates a challenge for pressure loss calculations. Computational fluid...

  12. A Residential Duct Leakage Case Study on 'Good Cents' Homes

    E-Print Network [OSTI]

    Bryant, J. A.; Perez, R.

    2001-01-01T23:59:59.000Z

    of round or rectangular ducts running through their walls, ceilings, attics, and basements. According to the Electric Power Research Institute (EPRI), even energy experts once believed that air duct leakage was insignificant (EPRI, 1992). In the late 1980s..., researchers began to realize that a significant relationship existed between residential air duct systems and energy loss (EPRI, 1996). Previous studies showed that air duct losses on the order of 35% were typical in residential construction (Jump, et...

  13. Potential Flow Calculations of Axisymmetric Ducted Wind Turbines

    E-Print Network [OSTI]

    Widnall, Sheila

    2009-09-02T23:59:59.000Z

    An incompressible potential-flow vortex method has been constructed to analyze the flow field of a ducted

  14. Improved Wireless Performance from Mode Scattering in Ventilation Ducts

    E-Print Network [OSTI]

    Stancil, Daniel D.

    Improved Wireless Performance from Mode Scattering in Ventilation Ducts Benjamin E. Henty, PA 15230. henty@eirp.org and stancil@cmu.edu Abstract Ventilation ducts are a convenient present in a ventilation duct T-junction and note with some surprise that improvement in the performance

  15. Model-Based Commissioning Methodology for Simple Duct System

    E-Print Network [OSTI]

    Odajima, T.; Takashi, M.; Juckel-Murakami, B.

    2004-01-01T23:59:59.000Z

    This paper presents how a simulation model is applied on air leakage and pressure distribution in a duct system and how it is utilized for duct system commissioning on the three categories below. It focuses on a duct system, which participates...

  16. Long Range Passive UHF RFID System Using HVAC Ducts

    E-Print Network [OSTI]

    Hochberg, Michael

    INVITED P A P E R Long Range Passive UHF RFID System Using HVAC Ducts To provide a potential communications channel, HVAC ducts can function as electromagnetic waveguides; a 30-m read range has been-conditioning (HVAC) ducts as a potential communication channel between passive ultrahigh-frequency (UHF) radio

  17. Nucleonic analysis of the ETF neutral-beam-injector-duct and vacuum-pumping-duct shields

    SciTech Connect (OSTI)

    Urban, W.T.; Seed, T.J.; Dudziak, D.J.

    1981-05-01T23:59:59.000Z

    A nucleonic analysis of the Engineering Test Facility neutral-beam-injector-duct and vacuum-pumping-duct shields has been made using a hybrid Monte Carlo/discrete-ordinates method. This method used Monte Carlo to determine internal and external boundary surface sources for subsequent discrete-ordinates calculations of the neutron and gamma-ray transport through the shields. Confidence was provided in both the hybrid method and the results obtained through a comparison with three-dimensional Monte Carlo results. Also determined in the analysis were the energy and angular distributions of neutrons and gamma rays entering the neutral-beam-injector duct from the toroidal plasma chamber, as well as exiting the duct into the neutral-beam-injector chamber. In addition, the energy and angular distributions of neutrons entering the vacuum-pumping chamber were determined.

  18. LBNL -45423 Stopping Duct Quacks: Longevity of

    E-Print Network [OSTI]

    of heating and cooling residential buildings (Energy Information Administration (EIA) 1997). The air amount of energy (30- 40%) being lost from the duct system instead of going to heating or cooling the conditioned space. In addition, a system with more supply leakage than return leakage causes a greater penalty

  19. THE M81 GROUP DWARF IRREGULAR GALAXY DDO 165. I. HIGH-VELOCITY NEUTRAL GAS IN A POST-STARBURST SYSTEM

    SciTech Connect (OSTI)

    Cannon, John M.; Most, Hans P. [Department of Physics and Astronomy, Macalester College, 1600 Grand Avenue, Saint Paul, MN 55105 (United States); Skillman, Evan D.; Weisz, Daniel R.; Warren, Steven R. [Astronomy Department, University of Minnesota, Minneapolis, MN 55455 (United States); Cook, David [Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071 (United States); Dolphin, Andrew E. [Raytheon Company, 1151 East Hermans Road, Tucson, AZ 85756 (United States); Kennicutt, Robert C. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Lee, Janice [Observatories of the Carnegie Institution of Washington, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Seth, Anil [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Walter, Fabian, E-mail: jcannon@macalester.edu, E-mail: skillman@astro.umn.edu, E-mail: dweisz@astro.umn.edu, E-mail: warren@astro.umn.edu, E-mail: dcook12@uwyo.edu, E-mail: adolphin@raytheon.com, E-mail: robk@ast.cam.ac.uk, E-mail: jlee@obs.carnegiescience.edu, E-mail: aseth@cfa.harvard.edu, E-mail: walter@mpia.de [Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, D-69117, Heidelberg (Germany)

    2011-07-01T23:59:59.000Z

    We present new multi-configuration Very Large Array H I spectral line observations of the M81 group dwarf irregular post-starburst galaxy DDO 165. The H I morphology is complex, with multiple column density peaks surrounding a large region of very low H I surface density that is offset from the center of the stellar distribution. The bulk of the neutral gas is associated with the southern section of the galaxy; a secondary peak in the north contains {approx}15% of the total H I mass. These components appear to be kinematically distinct, suggesting that either tidal processes or large-scale blowout have recently shaped the interstellar medium (ISM) of DDO 165. Using spatially resolved position-velocity maps, we find multiple localized high-velocity gas features. Cross-correlating with radius-velocity analyses, we identify eight shell/hole structures in the ISM with a range of sizes ({approx}400-900 pc) and expansion velocities ({approx}7-11 km s{sup -1}). These structures are compared with narrow- and broadband imaging from the Kitt Peak National Observatory and the Hubble Space Telescope (HST). Using the latter data, recent works have shown that DDO 165's previous 'burst' phase was extended temporally ({approx}>1 Gyr). We thus interpret the high-velocity gas features, H I holes, and kinematically distinct components of the galaxy in the context of the immediate effects of 'feedback' from recent star formation (SF). In addition to creating H I holes and shells, extended SF events are capable of creating localized high-velocity motion of the surrounding interstellar material. A companion paper connects the energetics from the H I and HST data.

  20. Density, porosity, mineralogy, and internal structure of cosmic dust and alteration of its properties during high velocity atmospheric entry

    E-Print Network [OSTI]

    Kohout, T; Suuronen, J -P; Rochette, P; Hutzler, A; Gattacceca, J; Skála, D D Badjukov R; Böhmová, V; ?uda, J

    2014-01-01T23:59:59.000Z

    X-ray microtomography (XMT), X-ray diffraction (XRD) and magnetic hysteresis measurements were used to determine micrometeorite internal structure, mineralogy, crystallography, and physical properties at ~{\\mu}m resolution. The study samples include unmelted, partially melted (scoriaceous) and completely melted (cosmic spherules) micrometeorites. This variety not only allows comparison of the mineralogy and porosity of these three micrometeorite types, but also reveals changes in meteoroid properties during atmospheric entry at various velocities. At low entry velocities, meteoroids do not melt, and their physical properties do not change. The porosity of unmelted micrometeorites varies considerably (0-12%) with one friable example having porosity around 50%. At higher velocities, the range of meteoroid porosity narrows, but average porosity increases (to 16-27%) due to volatile evaporation and partial melting (scoriaceous phase). Metal distribution seems to be mostly unaffected at this stage. At even higher ...

  1. The radial-velocity revolution

    SciTech Connect (OSTI)

    Griffin, R. (Cambridge Univ., Observatories (England))

    1989-09-01T23:59:59.000Z

    Instruments and techniques designed for registering the minute Doppler shifts arising from stellar radial velocity are examined. Particular attention is given to the photographic spectrographs, the high-dispersion spectrographs ('digital speedometers'), and the Palomar spectrometer. The principle of using radial-velocity masks is described, and the use of interferometers for radial-velocity measurements is discussed. Results are presented of radial velocity observations for HD 114762, HD 210647, and Epsilon Tauri, together with interpretations of these results.

  2. MATTER MIXING IN ASPHERICAL CORE-COLLAPSE SUPERNOVAE: A SEARCH FOR POSSIBLE CONDITIONS FOR CONVEYING {sup 56}Ni INTO HIGH VELOCITY REGIONS

    SciTech Connect (OSTI)

    Ono, Masaomi; Nagataki, Shigehiro; Ito, Hirotaka; Lee, Shiu-Hang; Mao, Jirong; Tolstov, Alexey [Astrophysical Big Bang Laboratory, RIKEN, Saitama 351-0198 (Japan); Hashimoto, Masa-aki, E-mail: masaomi.ono@riken.jp [Department of Physics, Kyushu University, Fukuoka 812-8581 (Japan)

    2013-08-20T23:59:59.000Z

    We perform two-dimensional axisymmetric hydrodynamic simulations of matter mixing in aspherical core-collapse supernova explosions of a 16.3 M{sub Sun} star with a compact hydrogen envelope. Observations of SN 1987A have provided evidence that {sup 56}Ni synthesized by explosive nucleosynthesis is mixed into fast moving matter ({approx}>3500 km s{sup -1}) in the exploding star. In order to clarify the key conditions for reproducing such high velocity of {sup 56}Ni, we revisit matter mixing in aspherical core-collapse supernova explosions. Explosions are initiated artificially by injecting thermal and kinetic energies around the interface between the iron core and the silicon-rich layer. Perturbations of 5% or 30% amplitude in the radial velocities are introduced at several points in time. We find that no high velocity {sup 56}Ni can be obtained if we consider bipolar explosions with perturbations (5% amplitude) of pre-supernova origins. If large perturbations (30% amplitude) are introduced or exist due to some unknown mechanism in a later phase just before the shock wave reaches the hydrogen envelope, {sup 56}Ni with a velocity of 3000 km s{sup -1} can be obtained. Aspherical explosions that are asymmetric across the equatorial plane with clumpy structures in the initial shock waves are investigated. We find that the clump sizes affect the penetration of {sup 56}Ni. Finally, we report that an aspherical explosion model that is asymmetric across the equatorial plane with multiple perturbations of pre-supernova origins can cause the penetration of {sup 56}Ni clumps into fast moving matter of 3000 km s{sup -1}. We show that both aspherical explosions with clumpy structures and perturbations of pre-supernova origins may be necessary to reproduce the observed high velocity of {sup 56}Ni. To confirm this, more robust three-dimensional simulations are required.

  3. MEASUREMENTS OF VELOCITY PROFILES AND SUSPENDED-SEDIMENT CONCENTRATIONS IN A COLORADO RIVER EDDY DURING HIGH FLOW

    E-Print Network [OSTI]

    averaged; suspended sediment is modeled through use of the advection-dispersion equation which yieldsMEASUREMENTS OF VELOCITY PROFILES AND SUSPENDED-SEDIMENT CONCENTRATIONS IN A COLORADO RIVER EDDY profiles and suspended-sediment concentration were made in a recirculating eddy along the Colorado River

  4. Measuring OutdoorAir Intake Rates Using Electronic Velocity Sensors at Louvers and Downstream of Airflow Straighteners

    SciTech Connect (OSTI)

    Fisk, William; Sullivan, Douglas; Cohen, Sebastian; Han, Hwataik

    2008-10-01T23:59:59.000Z

    Practical and accurate technologies are needed for continuously measuring and controlling outdoor air (OA) intake rates in commercial building heating, ventilating, and air conditioning (HVAC) systems. This project evaluated two new measurement approaches. Laboratory experiments determined that OA flow rates were measurable with errors generally less than 10percent using electronic air velocity probes installed between OA intake louver blades or at the outlet face of louvers. High accuracy was maintained with OA flow rates as low as 15percent of the maximum for the louvers. Thus, with this measurement approach HVAC systems do not need separate OA intakes for minimum OA supply. System calibration parameters are required for each unique combination of louver type and velocity sensor location but calibrations are not necessary for each system installation. The research also determined that the accuracy of measuring OA flow rates with velocity probes located in the duct downstream of the intake louver was not improved by installing honeycomb airflow straighteners upstream of the probes. Errors varied with type of upstream louver, were as high as 100percent, and were often greater than 25percent. In conclusion, use of electronic air velocity probes between the blades of OA intake louvers or at the outlet face of louvers is a highly promising means of accurately measuring rates of OA flow into HVAC systems. The use of electronic velocity probes downstream of airflow straighteners is less promising, at least with the relatively small OA HVAC inlet systems employed in this research.

  5. Buried and Encapsulated Ducts, Jacksonville, Florida (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2013-11-01T23:59:59.000Z

    Ductwork installed in unconditioned attics can significantly increase the overall heating and cooling costs of residential buildings. In fact, estimated duct thermal losses for single-family residential buildings with ductwork installed in unconditioned attics range from 10% to 45%. In a study of three single-story houses in Florida, the Building America research team Consortium for Advanced Residential Buildings (CARB) investigated the strategy of using buried and/or encapsulated ducts (BED) to reduce duct thermal losses in existing homes. The BED strategy consists of burying ducts in loose-fill insulation and/or encapsulating them in closed cell polyurethane spray foam (ccSPF) insulation. There are three possible combinations of BED strategies: (1) buried ducts; (2) encapsulated ducts (with ccSPF); and (3) buried and encapsulated ducts. The best solution for each situation depends on the climate, age of the house, and the configuration of the HVAC system and attic. For new construction projects, the team recommends that ducts be both encapsulated and buried as the minimal planning and costs required for this will yield optimal energy savings. The encapsulated/buried duct strategy, which utilizes ccSPF to address condensation concerns, is an approach that was developed specifically for humid climates.

  6. air duct work: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Distribution System Efficiency to Climate, Duct Location, Air Leakage and Insulation Energy Storage, Conversion and Utilization Websites Summary: 1 LBNL 43371 Sensitivity of...

  7. air heater duct: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    I. S.; Liu, M. 2001-01-01 5 Sensitivity of Forced Air Distribution System Efficiency to Climate, Duct Location, Air Leakage and Insulation Energy Storage, Conversion and...

  8. DOE Challenge Home Technical Training - Ducts in Conditioned...

    Broader source: Energy.gov (indexed) [DOE]

    of Energy Challenge Home program: Design Options for Locating Ducts within Conditioned Space. challengehometechnicaltraining.pdf More Documents & Publications DOE Zero Energy...

  9. Duct injection technology prototype development: Evaluation of engineering data

    SciTech Connect (OSTI)

    Not Available

    1990-07-01T23:59:59.000Z

    The objective of the Duct Injection Technology Prototype Development Project is to develop a sound design basis for applying duct injection technology as a post-combustion SO{sub 2}emissions control method to existing coal-fired power plants. The necessary engineering design and scale-up criteria will be developed for the commercialization of duct injection technology for the control of SO{sub 2} emissions from coal-fired boilers in the utility industry. The primary focus of the analyses summarized in this Topical Report is the review of the known technical and economic information associated with duct injection technology. (VC)

  10. Leaf seal for transition duct in turbine system

    DOE Patents [OSTI]

    Flanagan, James Scott; LeBegue, Jeffrey Scott; McMahan, Kevin Weston; Dillard, Daniel Jackson; Pentecost, Ronnie Ray

    2013-06-11T23:59:59.000Z

    A turbine system is disclosed. In one embodiment, the turbine system includes a transition duct. The transition duct includes an inlet, an outlet, and a passage extending between the inlet and the outlet and defining a longitudinal axis, a radial axis, and a tangential axis. The outlet of the transition duct is offset from the inlet along the longitudinal axis and the tangential axis. The transition duct further includes an interface member for interfacing with a turbine section. The turbine system further includes a leaf seal contacting the interface member to provide a seal between the interface member and the turbine section.

  11. Flexible metallic seal for transition duct in turbine system

    DOE Patents [OSTI]

    Flanagan, James Scott; LeBegue, Jeffrey Scott; McMahan, Kevin Weston; Dillard, Daniel Jackson; Pentecost, Ronnie Ray

    2014-04-22T23:59:59.000Z

    A turbine system is disclosed. In one embodiment, the turbine system includes a transition duct. The transition duct includes an inlet, an outlet, and a passage extending between the inlet and the outlet and defining a longitudinal axis, a radial axis, and a tangential axis. The outlet of the transition duct is offset from the inlet along the longitudinal axis and the tangential axis. The transition duct further includes an interface member for interfacing with a turbine section. The turbine system further includes a flexible metallic seal contacting the interface member to provide a seal between the interface member and the turbine section.

  12. Development of an analytic core flow approximation for a square duct in an oblique magnetic field

    SciTech Connect (OSTI)

    Morley, N.B.; Tillack, M.S.; Abdou, M.A.

    1991-03-01T23:59:59.000Z

    The core flow approximation for liquid metal (LM), magnetohydrodynamic (MHD) duct flow is a method that ignores the contributions of viscous forces in the fluid. For a fully developed, steady state flow situation, this approximation leaves the magnetic forces to be balanced only by the pressure gradient and results in a greatly simplified momentum equation. The velocity field predicted by the core flow equations is obtained much more easily than that described by the full solution, which usually requires a numerical approach. For this reason it is desirable to use the core flow method for flow situations in which viscosity has little effect. Developed here is an analytic core flow solution for a square duct in an obliquely incident magnetic field which omits any special treatment of boundary layers. This solution is compared to the full solution method developed in the code MH2D and a parametric comparison is performed. This general analytic approach can be expanded to consider rectangular ducts or walls of different thickness and electrical conductivity. The latter, however, will greatly complicate the equations presented here.

  13. Global modes, receptivity, and sensitivity analysis of diffusion flames coupled with duct

    E-Print Network [OSTI]

    Magri, Luca; Juniper, Matthew P.

    2015-01-01T23:59:59.000Z

    to the performance of the system. These oscillations are a persistent problem. Their comprehension, prediction and control in the design of gas turbines and rocket engines are areas of current research, as reviewed by Lieuwen & Yang (2005); Culick (2006... ,B,C,D and in the online supplementary material. 2. Thermo-acoustic model The thermo-acoustic model consists of a diffusion flame placed in an acoustic duct (figure 1). The acoustic waves cause perturbations in the velocity field. In turn, these Receptivity and sensitivity...

  14. Development of a High Resolution X-Ray Imaging Crystal Spectrometer for Measurement of Ion-Temperature and Rotation-Velocity Profiles in Fusion Energy Research Plasmas

    SciTech Connect (OSTI)

    Hill, K W; Broennimann, Ch; Eikenberry, E F; Ince-Cushman, A; Lee, S G; Rice, J E; Scott, S

    2008-02-27T23:59:59.000Z

    A new imaging high resolution x-ray crystal spectrometer (XCS) has been developed to measure continuous profiles of ion temperature and rotation velocity in fusion plasmas. Following proof-of-principle tests on the Alcator C-Mod tokamak and the NSTX spherical tokamak, and successful testing of a new silicon, pixilated detector with 1MHz count rate capability per pixel, an imaging XCS is being designed to measure full profiles of Ti and v? on C-Mod. The imaging XCS design has also been adopted for ITER. Ion-temperature uncertainty and minimum measurable rotation velocity are calculated for the C-Mod spectrometer. The affects of x-ray and nuclear-radiation background on the measurement uncertainties are calculated to predict performance on ITER.

  15. Development of a High Resolution X-Ray Imaging Crystal Spectrometer for Measurement of Ion-Temperature and Rotation-Velocity Profiles in Fusion Energy Research Plasmas

    SciTech Connect (OSTI)

    Hill, K W; Broennimann, Ch; Eikenberry, E F; Ince-Cushman, A; Lee, S G; Rice, J E; Scott, S

    2008-01-29T23:59:59.000Z

    A new imaging high resolution x-ray crystal spectrometer (XCS) has been developed to measure continuous profiles of ion temperature and rotation velocity in fusion plasmas. Following proof-of-principle tests on the Alcator C-Mod tokamak and the NSTX spherical tokamak, and successful testing of a new silicon, pixilated detector with 1 MHz count rate capability per pixel, an imaging XCS is being designed to measure full profiles of Ti and v? on C-Mod. The imaging XCS design has also been adopted for ITER. Ion-temperature uncertainty and minimum measurable rotation velocity are calculated for the C-Mod spectrometer. The affects of x-ray and uclear-radiation background on the measurement uncertainties are calculated to predict performance on ITER.

  16. Tips: Air Ducts | Department of Energy

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directed off Energy.gov. Are you sure you want toworldPower 2010 1 TNews & Solar Solar HowDucts Tips: Air

  17. Recovery of uranium from seawater; 15: Development of amidoxime resins with high sedimentation velocity for passively driver fluidized bed adsorbers

    SciTech Connect (OSTI)

    Egawa, Hiroaki; Kabay, N.; Jyo, A.; Hirono, Masaki; Shuto, Taketomi (Kumamoto Univ. (Japan). Dept. of Applied Chemistry)

    1994-03-01T23:59:59.000Z

    In order to design the amidoxime resins (RNH) suitable for circulating fluidized bed adsorbers, RNH were prepared from precursory acrylonitrile-divinylbenzene copolymer beads of different particle sizes, and chemical and physical properties of the resulting RNH were evaluated. Specific surface areas, pore structures, swelling ratios, and anion and cation-exchange capacities of RNH are little affected by the particle size, while their sedimentation velocities in water increase with an increase in particle size as expected from fluid dynamics. Although the uptake of uncomplexed uranyl ion from a uranyl nitrate solution (0.01 M) was not influenced by the particle size, the uranium uptake from seawater decreases with an increase in the particle size, indicating that the particle diffusion of the bulky complexed species UO[sub 2](CO[sub 3])[sub 3][sup 4[minus

  18. The design and construction of a high-resolution velocity-map imaging apparatus for photoelectron spectroscopy studies of size-selected clusters

    SciTech Connect (OSTI)

    León, Iker; Yang, Zheng; Liu, Hong-Tao; Wang, Lai-Sheng, E-mail: Lai-Sheng-Wang@brown.edu [Department of Chemistry, Brown University, Providence, Rhode Island 02912 (United States)

    2014-08-15T23:59:59.000Z

    A new velocity-map imaging apparatus equipped with a laser-vaporization supersonic cluster source and a time-of-flight mass spectrometer is described for high-resolution photoelectron spectroscopy studies of size-selected cluster anions. Vibrationally cold anion clusters are produced using a laser-vaporization supersonic cluster source, size-selected by a time-of-flight mass spectrometer, and then focused co-linearly into the interaction zone of the high-resolution velocity-map imaging (VMI) system. The multilens VMI system is optimized via systematic simulations and can reach a resolution of 1.2 cm{sup ?1} (FWHM) for near threshold electrons while maintaining photoelectron kinetic energy resolutions (?KE/KE) of ?0.53% for higher energy electrons. The new VMI lens has superior focusing power over a large energy range, yielding highly circular images with distortions no larger than 1.0025 between the long and short radii. The detailed design, simulation, construction, testing, and performance of the high-resolution VMI apparatus are presented.

  19. Slow sound in lined flow ducts

    E-Print Network [OSTI]

    Auregan, Yves

    2015-01-01T23:59:59.000Z

    We consider the acoustic propagation in lined flow duct with a purely reactive impedance at the wall. This reacting liner has the capability to reduce the speed of sound, and thus to enhance the interaction between the acoustic propagation and the low Mach number flow ($M\\simeq0.3$). At the lower frequencies, there are typically 4 acoustic or hydrodynamic propagating modes, with 3 of them propagating in the direction of the flow. Above a critical frequency, there are only 2 propagating modes that all propagate in the direction of the flow. From the exact 2D formulation an approximate 1D model is developed to study the scattering of acoustic waves in a straight duct with varying wall impedance. This simple system, with a uniform flow and with a non-uniform liner impedance at the wall, permits to study the scattering between regions with different waves characteristics. Several situations are characterized to show the importance of negative energy waves, strong interactions between acoustic and hydrodynamic mod...

  20. Handover Performance of HVAC Duct Based Indoor Wireless Networks

    E-Print Network [OSTI]

    Stancil, Daniel D.

    in indoor wireless net- works (IWN) that use heating, ventilation, and air conditioning (HVAC) ducts]. An alternative approach to transmitt/receive the RF signal is to use heating, ventilation, and airconditioning and is connected to one or more antennas in the duct. Each antenna acts as a remote antenna (RA) for a particular

  1. Evaluation of Polyurethane Nasolacrimal Duct Stents: In Vivo Studies in New Zealand Rabbits

    SciTech Connect (OSTI)

    Wilhelm, K.E., E-mail: wilhelm@uni-bonn.de; Grabolle, B.; Urbach, H. [University Hospital Bonn, Department of Radiology (Germany); Tolba, R. [Clinics of the University of Bonn, Haus fuer Experimentelle Therapie (Germany); Schild, H. [University Hospital Bonn, Department of Radiology (Germany); Paulsen, F. [Martin Luther University of Halle-Wittenberg, Department of Anatomy and Cell Biology (Germany)

    2006-10-15T23:59:59.000Z

    The purpose of this study was to evaluate the radiographic and biological effects of different polyurethane nasolacrimal duct stents in an animal model. Fifteen polyurethane nasolacrimal duct stents (n = 5 mushroom-type stents, n = 5 newly designed S-shaped TearLeader stents without hydrophilic coating, and n = 5 S-shaped TearLeader stents with hydrophilic coating) were implanted in the nasolacrimal ducts of eight unaffected New Zealand rabbits. One nasolacrimal system served as control. Clinical and radiographic follow-up was performed at 1-, 2-, and 4-week intervals, then after a 3-month interval, after which the animals were euthanized. All stents were implanted without major periprocedural complications. The stents proved to be patent by the end of the procedure. During follow-up, all mushroom-type stents were occluded at 4 weeks. None of these stents opened to forced irrigation. Clinically, all rabbits demonstrated severe dacryocystitis. Three out of five TearLeader stents without hydrophilic coating were blocked at 4 weeks; one out of five was open to irrigation. Best results were observed in the stent group with hydrophilic coating. Follow-up dacryocystography demonstrated patent stents in nasolacrimal ducts of all animals after 4 weeks. In only one of five cases, the coated stent became partially occluded after 2 months. These animals were free of clinical symptoms. After 3 months, at least three out of five stents still opened to forced irrigation and only one stent was completely blocked. Dislocation of the stents was not observed. Refinement of the stent surface and stent design improves the results of nasolacrimal duct stenting in this animal model. Implantation of hydrophilic-coated S-shaped stents is highly superior to conventional mushroom-type stents and noncoated stent types. Hydrophilic coating seems to prevent foreign-body reactions, resulting in maximized stent patency.

  2. Acoustic imaging of a duct spinning mode by the use of an in-duct circular microphone array

    E-Print Network [OSTI]

    Huang, Xun

    acoustic images of spinning modes in a duct cross section in real-time. Advanced signal processing theory duct. In particular, the rotating fan and stator assembly is mainly responsible for the generation be mounted on a pipe to stimulate a spinning mode. The sound propagation process can be simu- lated using

  3. Duct injection technology prototype development: Nozzle development Subtask 4.1, Atomizer specifications for duct injection technology. Topical report 8

    SciTech Connect (OSTI)

    Not Available

    1992-02-01T23:59:59.000Z

    Babcock & Wilcox has conducted a program to identify atomizers appropriate for successful in-duct injection of humidification water and lime slurries. The purpose of this program was to identify and quantify atomizer spray and performance criteria that affect the operations and reliability of the in-duct SO{sub 2} removal process, and compare commercially available atomizers to these criteria.

  4. New Insights for Improving the Designs of Flexible Duct Junction Boxes (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2014-01-01T23:59:59.000Z

    IBACOS explored the relationships between pressure and physical configurations of flexible duct junction boxes by using computational fluid dynamics (CFD) simulations to predict individual box parameters and total system pressure, thereby ensuring improved HVAC performance. Current Air Conditioning Contractors of America (ACCA) guidance (Group 11, Appendix 3, ACCA Manual D, Rutkowski 2009) allows for unconstrained variation in the number of takeoffs, box sizes, and takeoff locations. The only variables currently used in selecting an equivalent length (EL) are velocity of air in the duct and friction rate, given the first takeoff is located at least twice its diameter away from the inlet. This condition does not account for other factors impacting pressure loss across these types of fittings. For each simulation, the IBACOS team converted pressure loss within a box to an EL to compare variation in ACCA Manual D guidance to the simulated variation. IBACOS chose cases to represent flows reasonably correlating to flows typically encountered in the field and analyzed differences in total pressure due to increases in number and location of takeoffs, box dimensions, and velocity of air, and whether an entrance fitting is included. The team also calculated additional balancing losses for all cases due to discrepancies between intended outlet flows and natural flow splits created by the fitting. In certain asymmetrical cases, the balancing losses were significantly higher than symmetrical cases where the natural splits were close to the targets. Thus, IBACOS has shown additional design constraints that can ensure better system performance.

  5. Evaluation of asbestos dust concentration in discharge air from a high-velocity low-volume vacuum system

    E-Print Network [OSTI]

    Daniel, Steven Hall

    1977-01-01T23:59:59.000Z

    of high energy particles through polycarbonates) were selected because they have a very smooth surface which causes the fi bers to be easily distinguished under the scanning electron microscope (SEM). The results obtained by Beckett indicate...

  6. QUASI-PERIODIC PROPAGATING SIGNALS IN THE SOLAR CORONA: THE SIGNATURE OF MAGNETOACOUSTIC WAVES OR HIGH-VELOCITY UPFLOWS?

    SciTech Connect (OSTI)

    De Pontieu, Bart [Lockheed Martin Solar and Astrophysics Laboratory, 3251 Hanover Street, Org. ADBS, Bldg. 252, Palo Alto, CA 94304 (United States); McIntosh, Scott W., E-mail: bdp@lmsal.co, E-mail: mscott@ucar.ed [High Altitude Observatory, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307 (United States)

    2010-10-20T23:59:59.000Z

    Since the discovery of quasi-periodic propagating oscillations with periods of order 3-10 minutes in coronal loops with TRACE and SOHO/EIT (and later with STEREO/EUVI and Hinode/EIS), they have been almost universally interpreted as evidence for propagating slow-mode magnetoacoustic waves in the low plasma {beta} coronal environment. Here we show that this interpretation is not unique, and that for coronal loops associated with plage regions (as opposed to sunspots), the presence of magnetoacoustic waves may not be the only cause for the observed quasi-periodicities. We focus instead on the ubiquitous, faint upflows at 50-150 km s{sup -1} that were recently discovered as blueward asymmetries of spectral line profiles in footpoint regions of coronal loops, and as faint disturbances propagating along coronal loops in EUV/X-ray imaging time series. These faint upflows are most likely driven from below and have been associated with chromospheric jets that are (partially) rapidly heated to coronal temperatures at low heights. These two scenarios (waves versus flows) are difficult to differentiate using only imaging data, but careful analysis of spectral line profiles indicates that faint upflows are likely responsible for some of the observed quasi-periodic oscillatory signals in the corona. We show that recent EIS measurements of intensity and velocity oscillations of coronal lines (which had previously been interpreted as direct evidence for propagating waves) are actually accompanied by significant oscillations in the line width that are driven by a quasi-periodically varying component of emission in the blue wing of the line. This faint additional component of blue-shifted emission quasi-periodically modulates the peak intensity and line centroid of a single Gaussian fit to the spectral profile with the same small amplitudes (respectively a few percent of background intensity and a few km s{sup -1}) that were previously used to infer the presence of slow-mode magnetoacoustic waves. Our results indicate that it is possible that a significant fraction of the quasi-periodicities observed with coronal imagers and spectrographs that have previously been interpreted as propagating magnetoacoustic waves are instead caused by these upflows. The different physical cause for coronal oscillations would significantly impact the prospects of successful coronal seismology using propagating disturbances in coronal loops.

  7. Sensitivity of forced air distribution system efficiency to climate, duct location, air leakage and insulation

    E-Print Network [OSTI]

    Walker, Iain

    2001-01-01T23:59:59.000Z

    Location, Air Leakage and Insulation Iain S. Walker Energy4 Duct Insulation, Location and Leakageinsulation

  8. Building America Webinar: High Performance Space Conditioning...

    Energy Savers [EERE]

    Webinar: High Performance Space Conditioning Systems, Part II - Compact Buried Ducts Building America Webinar: High Performance Space Conditioning Systems, Part II - Compact Buried...

  9. Method and apparatus for duct sealing using a clog-resistant insertable injector

    DOE Patents [OSTI]

    Wang, Duo (Albany, CA); Modera, Mark P. (Piedmont, CA)

    2010-12-14T23:59:59.000Z

    A method for forming a duct access region through one side of a previously installed air duct, wherein the air duct has an air flow with an air flow direction by inserting an aerosol injector into a previously installed air duct through the access region. The aerosol injector includes a liquid tube having a liquid tube orifice for ejecting a liquid to be atomized; and a propellant cap. The method is accomplished by aligning the aerosol injector with the direction of air flow in the duct; activating an air flow within the duct; and spraying a sealant through the aerosol injector to seal the duct in the direction of the air flow.

  10. The structural and mechanical properties of a Cu??Zr??(at. %) alloy processed by High-Velocity-Injection (HVI)

    E-Print Network [OSTI]

    Hays, Charles C.

    1986-01-01T23:59:59.000Z

    /vacuum coupled pressure gradient. The molten jet rapidly solidifies, as it is in good thermal contact wi th the cir- cular walls of the copper channel. This process (melting and injection) is carried out in inert protective atmospheres (helium). The samples... produced are in the form of cylindrical rods with large length to diameter ratios (40:1). The samples exhibit a good sur- face finish and are of high density. The structural and mechanical characterization of the Cu6 Zr 0(at. %%u) samples produced...

  11. A ``NEW'' APPROACH TO ACTIVE NOISE CONTROL IN DUCTS 1

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    fail to quiet. There exists a potential for reducing acoustic pollution by attenuating fan and blower of acoustic feedback which is prevalent in duct systems; see [3]. A natural approach to these adaptive schemes

  12. Flow control optimization in a jet engine serpentine inlet duct

    E-Print Network [OSTI]

    Kumar, Abhinav

    2009-05-15T23:59:59.000Z

    Computational investigations were carried out on an advanced serpentine jet engine inlet duct to understand the development and propagation of secondary flow structures. Computational analysis which went in tandem with experimental investigation...

  13. DOE Zero Energy Ready Home Webinar: Ducts in Conditioned Space

    Broader source: Energy.gov [DOE]

    DOE Challenge Home is a blueprint for zero energy ready homes.  When we make that statement – it’s impossible to justify huge thermal losses from ducts in unconditioned spaces.  That’s why one of...

  14. STATE OF CALIFORNIA SPACE CONDITIONING SYSTEMS, DUCTS AND FANS

    E-Print Network [OSTI]

    , crawl- space, etc.) Duct R-value Heating Load (Btu/hr) Heating Capacity (Btu/hr) Equip Type (package Load (Btu/hr) Cooling Capacity (Btu/hr) 1. If project is new construction, see Footnotes to Standards

  15. Single channel double-duct liquid metal electrical generator using a magnetohydrodynamic device

    DOE Patents [OSTI]

    Haaland, Carsten M. (Dadeville, AL); Deeds, W. Edward (Knoxville, TN)

    1999-01-01T23:59:59.000Z

    A single channel double-duct liquid metal electrical generator using a magnetohydrodynamic (MHD) device. The single channel device provides useful output AC electric energy. The generator includes a two-cylinder linear-piston engine which drives liquid metal in a single channel looped around one side of the MHD device to form a double-duct contra-flowing liquid metal MHD generator. A flow conduit network and drive mechanism are provided for moving liquid metal with an oscillating flow through a static magnetic field to produce useful AC electric energy at practical voltages and currents. Variable stroke is obtained by controlling the quantity of liquid metal in the channel. High efficiency is obtained over a wide range of frequency and power output.

  16. Single channel double-duct liquid metal electrical generator using a magnetohydrodynamic device

    DOE Patents [OSTI]

    Haaland, C.M.; Deeds, W.E.

    1999-07-13T23:59:59.000Z

    A single channel double-duct liquid metal electrical generator using a magnetohydrodynamic (MHD) device. The single channel device provides useful output AC electric energy. The generator includes a two-cylinder linear-piston engine which drives liquid metal in a single channel looped around one side of the MHD device to form a double-duct contra-flowing liquid metal MHD generator. A flow conduit network and drive mechanism are provided for moving liquid metal with an oscillating flow through a static magnetic field to produce useful AC electric energy at practical voltages and currents. Variable stroke is obtained by controlling the quantity of liquid metal in the channel. High efficiency is obtained over a wide range of frequency and power output. 5 figs.

  17. 44 Market St - Refurbishment of a Dual Duct Building

    E-Print Network [OSTI]

    Bannister, P.; Foo, G.

    2013-01-01T23:59:59.000Z

    Page 1 of 9 44 MARKET ST ? REFURBISHMENT OF A DUAL DUCT BUILDING ? ? DR PAUL BANNISTER Managing Director Exergy Australia Pty Ltd Canberra, ACT, Australia GRACE FOO Consultant Exergy Australia Pty Ltd Canberra, ACT, Australia ? ABSTRACT...-zone dual duct unit with a single supply fan and separate cooling and heating coils serving the retail bank and optometrist tenancies. AHU-6 (caf?) was a constant volume system equipped with cooling and heating coils. AHU-B1 (Australia Post on Basement...

  18. BETTER DUCT SYSTEMS FOR HOME HEATING AND COOLING.

    SciTech Connect (OSTI)

    ANDREWS,J.

    2001-01-01T23:59:59.000Z

    This is a series of six guides intended to provide a working knowledge of residential heating and cooling duct systems, an understanding of the major issues concerning efficiency, comfort, health, and safety, and practical tips on installation and repair of duct systems. These guides are intended for use by contractors, system designers, advanced technicians, and other HVAC professionals. The first two guides are also intended to be accessible to the general reader.

  19. Study of Chelyabinsk LL5 meteorite fragment with a light lithology and its fusion crust using Mössbauer spectroscopy with a high velocity resolution

    SciTech Connect (OSTI)

    Maksimova, Alevtina A.; Petrova, Evgeniya V.; Grokhovsky, Victor I. [Department of Physical Techniques and Devices for Quality Control, Institute of Physics and Technology, Ural Federal University, Ekaterinburg, 620002 (Russian Federation); Oshtrakh, Michael I., E-mail: oshtrakh@gmail.com; Semionkin, Vladimir A. [Department of Physical Techniques and Devices for Quality Control, Institute of Physics and Technology, Ural Federal University, Ekaterinburg, 620002, Russian Federation and Department of Experimental Physics, Institute of Physics and Technology, Ura (Russian Federation)

    2014-10-27T23:59:59.000Z

    Study of Chelyabinsk LL5 ordinary chondrite fragment with a light lithology and its fusion crust, fallen on February 15, 2013, in Russian Federation, was carried out using Mössbauer spectroscopy with a high velocity resolution. The Mössbauer spectra of the internal matter and fusion crust were fitted and all components were related to iron-bearing phases such as olivine, pyroxene, troilite, Fe-Ni-Co alloy, and chromite in the internal matter and olivine, pyroxene, troilite, Fe-Ni-Co alloy, and magnesioferrite in the fusion crust. A comparison of the content of different phases in the internal matter and in the fusion crust of this fragment showed that ferric compounds resulted from olivine, pyroxene, and troilite combustion in the atmosphere.

  20. Measure Guideline: Buried and/or Encapsulated Ducts

    SciTech Connect (OSTI)

    Shapiro, C.; Zoeller, W.; Mantha, P.

    2013-08-01T23:59:59.000Z

    Buried and/or encapsulated ducts (BEDs) are a class of advanced, energy-efficiency strategies intended to address the significant ductwork thermal losses associated with ducts installed in unconditioned attics. BEDs are ducts installed in unconditioned attics that are covered in loose-fill insulation and/or encapsulated in closed cell polyurethane spray foam insulation. This Measure Guideline covers the technical aspects of BEDs as well as the advantages, disadvantages, and risks of BEDs compared to other alternative strategies. This guideline also provides detailed guidance on installation of BEDs strategies in new and existing homes through step-by-step installation procedures. This Building America Measure Guideline synthesizes previously published research on BEDs and provides practical information to builders, contractors, homeowners, policy analysts, building professions, and building scientists. Some of the procedures presented here, however, require specialized equipment or expertise. In addition, some alterations to duct systems may require a specialized license. Persons implementing duct system improvements should not go beyond their expertise or qualifications. This guideline provides valuable information for a building industry that has struggled to address ductwork thermal losses in new and existing homes. As building codes strengthen requirements for duct air sealing and insulation, flexibility is needed to address energy efficiency goals. While ductwork in conditioned spaces has been promoted as the panacea for addressing ductwork thermal losses, BEDs installations approach - and sometimes exceed - the performance of ductwork in conditioned spaces.

  1. WAVE PROPAGATION in the HOT DUCT of VHTR

    SciTech Connect (OSTI)

    Richard Schultz; Jim C. P. Liou

    2013-07-01T23:59:59.000Z

    In VHTR, helium from the reactor vessel is conveyed to a power conversion unit through a hot duct. In a hypothesized Depressurized Conduction Cooldown event where a rupture of the hot duct occurs, pressure waves will be initiated and reverberate in the hot duct. A numerical model is developed to quantify the transients and the helium mass flux through the rupture for such events. The flow path of the helium forms a closed loop but only the hot duct is modeled in this study. The lower plum of the reactor vessel and the steam generator are treated as specified pressure and/or temperature boundary to the hot duct. The model is based on the conservation principles of mass, momentum and energy, and on the equations of state for helium. The numerical solution is based on the method of characteristics with specified time intervals with a predictor and corrector algorithm. The rupture sub-model gives reasonable results. Transients induced by ruptures with break area equaling 20%, 10%, and 5% of the duct cross-sectional area are described.

  2. Prediction of turbulent flow and heat transfer in a ribbed rectangular duct with and without rotation

    SciTech Connect (OSTI)

    Prakash, C.; Zerkle, R. [General Electric Co., Cincinnati, OH (United States)

    1995-04-01T23:59:59.000Z

    The present study deals with the numerical prediction of turbulent flow and heat transfer in a 2:1 aspect ratio rectangular duct with ribs don the two shorter sides. The ribs are of square cross section, staggered and aligned normal (90 deg) to the main flow direction. The ratio of rib height to duct hydraulic diameter equals 0.063, and the ratio of rib spacing to rib height equals 10. The duct may be stationary or rotating. The axis of rotation is normal to the axis of the duct and parallel to the ribbed walls (i.e., the ribbed walls form the leading and the trailing faces). The problem is three dimensional and fully elliptic; hence, for computational economy, the present analysis deals only with a periodically fully developed situation where the calculation domain is limited to the region between two adjacent ribs. Turbulence is modeled with the {kappa}-{epsilon} model in conjunction with wall functions. However, since the rib height is small, use of wall functions necessitates that the Reynolds number be kept high. (Attempts to use a two-layer model that permits integration to the wall did not yield satisfactory results and such modeling issues are discussed at length.) Computations are made here for Reynolds number in the range 30,000--100,000 and for Rotation number = 0 (stationary), 0.06, and 0.12. For the stationary case, the predicted heat transfer agrees well with the experimental correlations. Due to the Coriolis-induced secondary flow, rotation is found to enhance heat transfer from the trailing and the side walls, while decreasing heat transfer from the leading face. Relative to the corresponding stationary case, the effect of rotation is found to be less for a ribbed channel as compared to a smooth channel.

  3. BONA FIDE, STRONG-VARIABLE GALACTIC LUMINOUS BLUE VARIABLE STARS ARE FAST ROTATORS: DETECTION OF A HIGH ROTATIONAL VELOCITY IN HR CARINAE

    SciTech Connect (OSTI)

    Groh, J. H. [Max-Planck-Institut fuer Radioastronomie, Auf dem Huegel 69, D-53121 Bonn (Germany); Damineli, A.; Moises, A. P.; Teodoro, M. [Instituto de Astronomia, Geofisica e Ciencias Atmosfericas, Universidade de Sao Paulo, Rua do Matao 1226, Cidade Universitaria, 05508-090, Sao Paulo, SP (Brazil); Hillier, D. J. [Department of Physics and Astronomy, University of Pittsburgh, 3941 O'Hara Street, Pittsburgh, PA 15260 (United States); Barba, R. [Departamento de fisica, Universidad de La Serena, Benavente 980, La Serena (Chile); Fernandez-Lajus, E.; Gamen, R. C.; Solivella, G., E-mail: jgroh@mpifr-bonn.mpg.d [Facultad de Ciencias Astronomicas y Geofisicas, Universidad Nacional de La Plata, and Instituto de Astrofisica de La Plata (CCT La Plata-CONICET), Paseo del Bosque S/N, B1900FWA, La Plata (Argentina)

    2009-11-01T23:59:59.000Z

    We report optical observations of the luminous blue variable (LBV) HR Carinae which show that the star has reached a visual minimum phase in 2009. More importantly, we detected absorptions due to Si IV lambdalambda4088-4116. To match their observed line profiles from 2009 May, a high rotational velocity of v{sub rot} approx = 150 +- 20 km s{sup -1} is needed (assuming an inclination angle of 30 deg.), implying that HR Car rotates at approx =0.88 +- 0.2 of its critical velocity for breakup (v{sub crit}). Our results suggest that fast rotation is typical in all strong-variable, bona fide galactic LBVs, which present S-Dor-type variability. Strong-variable LBVs are located in a well-defined region of the HR diagram during visual minimum (the 'LBV minimum instability strip'). We suggest this region corresponds to where v{sub crit} is reached. To the left of this strip, a forbidden zone with v{sub rot}/v{sub crit}>1 is present, explaining why no LBVs are detected in this zone. Since dormant/ex LBVs like P Cygni and HD 168625 have low v{sub rot}, we propose that LBVs can be separated into two groups: fast-rotating, strong-variable stars showing S-Dor cycles (such as AG Car and HR Car) and slow-rotating stars with much less variability (such as P Cygni and HD 168625). We speculate that supernova (SN) progenitors which had S-Dor cycles before exploding (such as in SN 2001ig, SN 2003bg, and SN 2005gj) could have been fast rotators. We suggest that the potential difficulty of fast-rotating Galactic LBVs to lose angular momentum is additional evidence that such stars could explode during the LBV phase.

  4. Fiberglass Duct Cleaning Safe Work Practices Duct Cleaning -Prior to reaching a decision to clean a duct, an investigation of possible

    E-Print Network [OSTI]

    de Lijser, Peter

    ­ Locations should be noted prior to conducting work. Lockers, Showers, and Hand Wash Sinks ­ Should to be sure that there are no hazardous containing materials in the duct system such as Asbestos. Asbestos into particulate collection equipment. 3. All equipment located outside should be placed downwind and away from

  5. Measure Guideline: Optimizing the Configuration of Flexible Duct Junction Boxes

    SciTech Connect (OSTI)

    Beach, R.; Burdick, A.

    2014-03-01T23:59:59.000Z

    This measure guideline offers additional recommendations to heating, ventilation, and air conditioning (HVAC) system designers for optimizing flexible duct, constant-volume HVAC systems using junction boxes within Air Conditioning Contractors of America (ACCA) Manual D guidance (Rutkowski, H. Manual D -- Residential Duct Systems, 3rd edition, Version 1.00. Arlington, VA: Air Conditioning Contractors of America, 2009.). IBACOS used computational fluid dynamics software to explore and develop guidance to better control the airflow effects of factors that may impact pressure losses within junction boxes among various design configurations (Beach, R., Prahl, D., and Lange, R. CFD Analysis of Flexible Duct Junction Box Design. Golden, CO: National Renewable Energy Laboratory, submitted for publication 2013). These recommendations can help to ensure that a system aligns more closely with the design and the occupants' comfort expectations. Specifically, the recommendations described herein show how to configure a rectangular box with four outlets, a triangular box with three outlets, metal wyes with two outlets, and multiple configurations for more than four outlets. Designers of HVAC systems, contractors who are fabricating junction boxes on site, and anyone using the ACCA Manual D process for sizing duct runs will find this measure guideline invaluable for more accurately minimizing pressure losses when using junction boxes with flexible ducts.

  6. Ducts in the Attic? What Were They Thinking? Preprint

    SciTech Connect (OSTI)

    Roberts, D.; Winkler, J.

    2010-08-01T23:59:59.000Z

    As energy-efficiency efforts focus increasingly on existing homes, we scratch our heads about construction decisions made 30, 40, 50-years ago and ask: 'What were they thinking?' A logical follow-on question is: 'What will folks think in 2050 about the homes we're building today?' This question can lead to a lively discussion, but the current practice that we find most alarming is placing ducts in the attic. In this paper, we explore through literature and analysis the impact duct location has on cooling load, peak demand, and energy cost in hot climates. For a typical new home in these climates, we estimate that locating ducts in attics rather than inside conditioned space increases the cooling load 0.5 to 1 ton, increases cooling costs 15% and increases demand by 0.75 kW. The aggregate demand to service duct loss in homes built in Houston, Las Vegas, and Phoenix during the period 2000 through 2009 is estimated to be 700 MW. We present options for building homes with ducts in conditioned space and demonstrate that these options compare favorably with other common approaches to achieving electricity peak demand and consumption savings in homes.

  7. 7/11/00-draft copy: do not quote 1 of 30 New Technologies for Residential HVAC Ducts

    E-Print Network [OSTI]

    in use or available and found that the only inexpensive ducts in production are insulated wireflex ducts metal duct which uses a rubber gasket was also found. Two companies are trying to develop plastic

  8. Keck-I MOSFIRE spectroscopy of compact star-forming galaxies at z$\\gtrsim$2: High velocity dispersions in progenitors of compact quiescent galaxies

    E-Print Network [OSTI]

    Barro, G; Koo, D C; Dekel, A; Kassin, S A; Kocevski, D D; Faber, S M; van der Wel, A; Guo, Y; Perez-Gonzalez, P G; Toloba, E; Fang, J J; Pacifici, C; Simons, R; Campbell, R D; Ceverino, D; Finkelstein, S L; Goodrich, B; Kassis, M; Koekemoer, A M; Konidaris, N P; Livermore, R C; Lyke, J E; Mobasher, B; Nayyeri, H; Peth, M; Primack, J R; Rizzi, L; Somerville, R S; Wirth, G D; Zolotov, A

    2014-01-01T23:59:59.000Z

    We present Keck-I MOSFIRE near-infrared spectroscopy for a sample of 13 compact star-forming galaxies (SFGs) at redshift $2\\leq z \\leq2.5$ with star formation rates of SFR$\\sim$100M$_{\\odot}$ y$^{-1}$ and masses of log(M/M$_{\\odot}$)$\\sim10.8$. Their high integrated gas velocity dispersions of $\\sigma_{\\rm{int}}$=230$^{+40}_{-30}$ km s$^{-1}$, as measured from emission lines of H$_{\\alpha}$ and [OIII], and the resultant M$_{\\star}-\\sigma_{\\rm{int}}$ relation and M$_{\\star}$$-$M$_{\\rm{dyn}}$ all match well to those of compact quiescent galaxies at $z\\sim2$, as measured from stellar absorption lines. Since log(M$_{\\star}$/M$_{\\rm{dyn}}$)$=-0.06\\pm0.2$ dex, these compact SFGs appear to be dynamically relaxed and more evolved, i.e., more depleted in gas and dark matter ($infusion of external gas, depletion timescales are short, less than $\\sim$300 Myr. This discovery adds another link to our new dynamical chain of evidence...

  9. CASE STUDY OF DUCT RETROFIT OF A 1985 HOME AND GUIDELINES FOR ATTIC AND CRAWL SPACE DUCT SEALING

    SciTech Connect (OSTI)

    Boudreaux, Philip R [ORNL; Christian, Jeffrey E [ORNL; Jackson, Roderick K [ORNL

    2012-01-01T23:59:59.000Z

    The U.S. Department of Energy (DOE) is fully committed to research for developing the information and capabilities necessary to provide cost-effective residential retrofits yielding 50% energy savings within the next several years. Heating, ventilation, and air conditioning (HVAC) is the biggest energy end use in the residential sector, and a significant amount of energy can be wasted through leaky ductwork in unconditioned spaces such as attics and crawl spaces. A detailed duct sealing case study is presented for one house along with nine brief descriptions of other duct retrofits completed in the mixed-humid climate. Costs and estimated energy savings are reported for most of the ten houses. Costs for the retrofits ranged from $0.92/ft2 to $1.80/ft2 of living space and estimated yearly energy cost savings due to the duct retrofits range from 1.8% to 18.5%. Lessons learned and duct sealing guidelines based on these ten houses, as well as close work with the HVAC industry in the mixed-humid climate of East Tennessee, northern Georgia, and south-central Kentucky are presented. It is hoped that the lessons learned and guidelines will influence local HVAC contractors, energy auditors, and homeowners when diagnosing or repairing HVAC duct leakage and will be useful for steering DOE s future research in this area.

  10. Advanced Strategy Guideline: Air Distribution Basics and Duct Design

    SciTech Connect (OSTI)

    Burdick, A.

    2011-12-01T23:59:59.000Z

    This report discusses considerations for designing an air distribution system for an energy efficient house that requires less air volume to condition the space. Considering the HVAC system early in the design process will allow adequate space for equipment and ductwork and can result in cost savings. Principles discussed that will maximize occupant comfort include delivery of the proper amount of conditioned air for appropriate temperature mixing and uniformity without drafts, minimization of system noise, the impacts of pressure loss, efficient return air duct design, and supply air outlet placement, as well as duct layout, materials, and sizing.

  11. Evaluation of friction loss in flexible and galvanized duct 

    E-Print Network [OSTI]

    Zimmermann, Carlos Michael Alberto

    1985-01-01T23:59:59.000Z

    or similar exterior material. 3. When exterior abrasion of the duct can be a factor, a vinyl scuff strip can be glued or plastic welded in spiral fashion on the outside cover. 4. Reduction in flow because of Internal friction can be minimized by using...EVALUATION OF FRICTION LOSS IN FLEXIBLE AND GALVANIZED DUCT A Thesis by CARLOS MICHAEL ALBERTO ZIMMERMANN Submitted to the Graduate College of Texas A&M University in partial fulfliiment of the requirements for the degree of MASTER...

  12. Evaluation of friction loss in flexible and galvanized duct

    E-Print Network [OSTI]

    Zimmermann, Carlos Michael Alberto

    1985-01-01T23:59:59.000Z

    for Friction Loss in Straight Runs of Duct (a'Ipha=0. 10). 21 Ill Static Pressure Data Converted to Equivalent Lengths. 23 IV Duncan's Multiple Range Test of Variability for Equivalent Lengths of 90 Degree Elbows (al pha=0. IO). 26 V Student t Test... in the system was controlled by a discharge damper and metered with an orifice meter. The static pressure data was collected by the use of a pizometer ring located at the exhaust portion of the test apparatus where the flexible duct was connected...

  13. Fundamental investigation of duct/ESP phenomena. Final report

    SciTech Connect (OSTI)

    Brown, C.A. [Radian Corp., Austin, TX (United States); Durham, M.D. [ADA Technologies, Inc., Englewood, CO (United States); Sowa, W.A. [California Univ., Irvine, CA (United States). Combustion Lab.; Himes, R.M. [Fossil Energy Research Corp., Laguna Hills, CA (United States); Mahaffey, W.A. [CHAM of North America, Inc., Huntsville, AL (United States)

    1991-10-21T23:59:59.000Z

    Radian Corporation was contracted to investigate duct injection and ESP phenomena in a 1.7 MW pilot plant constructed for this test program. This study was an attempt to resolve problems found in previous studies and answer remaining questions for the technology using an approach which concentrates on the fundamental mechanisms of the process. The goal of the study was to obtain a better understanding of the basic physical and chemical phenomena that control: (1) the desulfurization of flue gas by calcium-based reagent, and (2) the coupling of an existing ESP particulate collection device to the duct injection process. Process economics are being studied by others. (VC)

  14. Sensitivity of Forced Air Distribution System Efficiency to Climate, Duct Location, Air Leakage and Insulation

    E-Print Network [OSTI]

    , Air Leakage and Insulation Iain S. Walker Energy Performance of Buildings Group Indoor Environment ................................................................................................................................................ 4 Duct Insulation, Location and Leakage Examples............................................................... 4 Figure 2. Sheet metal ducts in a basement insulated with asbestos

  15. Tracer Gas as a Practical Field Diagnostic Tool for Assessing Duct System Leaks

    E-Print Network [OSTI]

    Cummings, J. B.

    1989-01-01T23:59:59.000Z

    A methodology is presented for using tracer gas testing to detect and quantify duct leakage in homes. Since air is invisible, leakage of air from duct systems often remains undetected. Smoke sticks used in conjunction with blower doors are excellent...

  16. Variable Speed Drive (VSD) Applications in Dual-Duct Constant Volume Systems

    E-Print Network [OSTI]

    Joo, I.; Liu, M.; Conger, K.; Wang, G.

    2002-01-01T23:59:59.000Z

    Models have been developed for static pressure and potential supply fan energy savings by using variable speed drive (VSD) in dual-duct constant volume systems. Experiments have been performed using a full size dual-duct constant volume system...

  17. Static Pressure Loss in 12”, 14”, and 16” Non-metallic Flexible Duct

    E-Print Network [OSTI]

    Cantrill, David Lee

    2013-08-01T23:59:59.000Z

    flow rate for a given duct size. The data gathered showed general agreement with previous studies showing an increase in compression ratio leads to an increase in static pressure loss through the duct. It was determined that pressure losses...

  18. Measure Guideline: Summary of Interior Ducts in New Construction, Including an Efficient, Affordable Method to Install Fur-Down Interior Ducts

    SciTech Connect (OSTI)

    Beal, D.; McIlvaine , J.; Fonorow, K.; Martin, E.

    2011-11-01T23:59:59.000Z

    This document illustrates guidelines for the efficient installation of interior duct systems in new housing, including the fur-up chase method, the fur-down chase method, and interior ducts positioned in sealed attics or sealed crawl spaces. This document illustrates guidelines for the efficient installation of interior duct systems in new housing. Interior ducts result from bringing the duct work inside a home's thermal and air barrier. Architects, designers, builders, and new home buyers should thoroughly investigate any opportunity for energy savings that is as easy to implement during construction, such as the opportunity to construct interior duct work. In addition to enhanced energy efficiency, interior ductwork results in other important advantages, such as improved indoor air quality, increased system durability and increased homeowner comfort. While the advantages of well-designed and constructed interior duct systems are recognized, the implementation of this approach has not gained a significant market acceptance. This guideline describes a variety of methods to create interior ducts including the fur-up chase method, the fur-down chase method, and interior ducts positioned in sealed attics or sealed crawl spaces. As communication of the intent of an interior duct system, and collaboration on its construction are paramount to success, this guideline details the critical design, planning, construction, inspection, and verification steps that must be taken. Involved in this process are individuals from the design team; sales/marketing team; and mechanical, insulation, plumbing, electrical, framing, drywall and solar contractors.

  19. Particle Concentration Dynamics in the Ventilation Duct after an Artificial Release: for Countering Potential Bioterriorist Attack

    E-Print Network [OSTI]

    You , Siming; Wan, Man Pun

    2014-01-01T23:59:59.000Z

    leads to In this work, the models of particle concentration dynamics in the ventilation duct following a resuspension

  20. Cooling air recycling for gas turbine transition duct end frame and related method

    DOE Patents [OSTI]

    Cromer, Robert Harold (Johnstown, NY); Bechtel, William Theodore (Scotia, NY); Sutcu, Maz (Niskayuna, NY)

    2002-01-01T23:59:59.000Z

    A method of cooling a transition duct end frame in a gas turbine includes the steps of a) directing cooling air into the end frame from a region external of the transition duct and the impingement cooling sleeve; and b) redirecting the cooling air from the end frame into the annulus between the transition duct and the impingement cooling sleeve.

  1. Performance Analysis of Dual-Fan, Dual-Duct Constant Volume Air-Handling Units

    E-Print Network [OSTI]

    Joo, I. S.; Liu, M.

    2001-01-01T23:59:59.000Z

    Dual-fan, dual-duct air-handling units introduce outside air directly into the cooling duct and use two variable speed devices to independently maintain the static pressure of the hot and the cold air ducts. Analytical models have been developed...

  2. Improving Control of a Dual-Duct Single-Fan Variable Air Volume Systems

    E-Print Network [OSTI]

    Wei, G.; Martinez, J.; Minihan, T.; Brundidge, T.; Claridge, D. E.; Turner, W. D.

    2003-01-01T23:59:59.000Z

    cold and hot air duct static pressure set points is presented. The paper also explores the interactions between the cold and hot deck temperatures and duct static pressures, and discusses the impact of non-ideal deck temperature settings on duct static...

  3. Static Pressure Losses in 6, 8, and 10-inch Non-Metallic Flexible Ducts

    E-Print Network [OSTI]

    Weaver, K.; Culp, C.

    2006-01-01T23:59:59.000Z

    This study measured airflow static pressure losses through non-metallic flexible ducts in compliance with ASHRAE Standard 120-1999, Methods of Testing to Determine Flow Resistance of HVAC Air Ducts and Fittings (ASHRAE 1999). Duct sizes of 6, 8...

  4. Static Pressure Losses in 6, 8, and 10-inch Non-Metallic Flexible Ducts 

    E-Print Network [OSTI]

    Weaver, K.; Culp, C.

    2006-01-01T23:59:59.000Z

    This study measured airflow static pressure losses through non-metallic flexible ducts in compliance with ASHRAE Standard 120-1999, Methods of Testing to Determine Flow Resistance of HVAC Air Ducts and Fittings (ASHRAE 1999). Duct sizes of 6, 8...

  5. 96 ASHRAE Transactions: Research Current duct design methods for variable air volume

    E-Print Network [OSTI]

    of the year. Conventional duct design methods do not account for the actual zone load profile. Consequently at an off-peak load condition, and the impact of varying airflow rates to the sizing of duct systems has.Hourlyairflowrequirements, part-load fan characteristics, and duct static pressure control are incorporated into the problem

  6. RF propagation in an HVAC duct system: impulse response characteristics of the channel

    E-Print Network [OSTI]

    Stancil, Daniel D.

    RF propagation in an HVAC duct system: impulse response characteristics of the channel Pavel V, the heating, ventilation, and air conditioning (HVAC) duct system in buildings is a complex network of hollow at RF and microwave frequencies of com- mon interest. HVAC ducts can be used as a wireless communication

  7. 44 Market St - Refurbishment of a Dual Duct Building 

    E-Print Network [OSTI]

    Bannister, P.; Foo, G.

    2013-01-01T23:59:59.000Z

    occupancy was 2 stars without Green Power. This paper describes the process of refurbishing the building including: Modifications to convert the air conditioning system to a variable volume dual duct system, re-using many of the components of the original...

  8. LBNL-41434. CAN DUCT-TAPE TAKE THE HEAT?

    E-Print Network [OSTI]

    LBNL-41434. 1 CAN DUCT-TAPE TAKE THE HEAT? Max Sherman Iain Walker Energy Performance of Buildings sponsor. #12;LBNL-41434. 2 As anyone who has crawled around attics looking at ductwork knows, the sight ratings for sealant longevity existed. To examine this question, LBNL has used laboratory methods

  9. Unitaxial constant velocity microactuator

    DOE Patents [OSTI]

    McIntyre, T.J.

    1994-06-07T23:59:59.000Z

    A uniaxial drive system or microactuator capable of operating in an ultra-high vacuum environment is disclosed. The mechanism includes a flexible coupling having a bore therethrough, and two clamp/pusher assemblies mounted in axial ends of the coupling. The clamp/pusher assemblies are energized by voltage-operated piezoelectrics therewithin to operatively engage the shaft and coupling causing the shaft to move along its rotational axis through the bore. The microactuator is capable of repeatably positioning to sub-nanometer accuracy while affording a scan range in excess of 5 centimeters. Moreover, the microactuator generates smooth, constant velocity motion profiles while producing a drive thrust of greater than 10 pounds. The system is remotely controlled and piezoelectrically driven, hence minimal thermal loading, vibrational excitation, or outgassing is introduced to the operating environment. 10 figs.

  10. Unitaxial constant velocity microactuator

    DOE Patents [OSTI]

    McIntyre, Timothy J. (Knoxville, TN)

    1994-01-01T23:59:59.000Z

    A uniaxial drive system or microactuator capable of operating in an ultra-high vacuum environment. The mechanism includes a flexible coupling having a bore therethrough, and two clamp/pusher assemblies mounted in axial ends of the coupling. The clamp/pusher assemblies are energized by voltage-operated piezoelectrics therewithin to operatively engage the shaft and coupling causing the shaft to move along its rotational axis through the bore. The microactuator is capable of repeatably positioning to sub-manometer accuracy while affording a scan range in excess of 5 centimeters. Moreover, the microactuator generates smooth, constant velocity motion profiles while producing a drive thrust of greater than 10 pounds. The system is remotely controlled and piezoelectrically driven, hence minimal thermal loading, vibrational excitation, or outgassing is introduced to the operating environment.

  11. Determination of the radioactive material and plutonium holdup in ducts and piping in the 324 Building

    SciTech Connect (OSTI)

    Haggard, D.L.; Brackenbush, L.W.; Tanner, J.E.

    1996-01-01T23:59:59.000Z

    This report describes the measurements Performed to determine the radionuclide content and mass of plutonium in exposed ducts, filters, and piping in the 324 Building at the US Department of Energy Hanford Site in Washington State. This information is needed to characterize facility radiation levels, to verify compliance with criticality safety specifications, and to allow more accurate nuclear material control using nondestructive assay (NDA) methods. Gamma assay techniques typically employed for NDA analysis were used to determine the gamma-emitting isotopes in the ducts, filters, and piping. Passive neutron counting was selected to estimate -the plutonium content because high gamma levels from fission and activation products effectively mask any gamma emissions from plutonium. A high-purity gamma-ray detector Was used to measure the mixed fission and activation radionuclides. A neutron slab detector containing five {sup 3}He proportional counters was used to determine the neutron emission rates and estimate the mass of plutonium present. Both measurement systems followed the methods and procedures routinely used for nuclear waste assay and safeguards measurements.

  12. Hemodynamic characterization of chronic bile duct-ligated rats: effect of pentobarbital sodium

    SciTech Connect (OSTI)

    Lee, S.S.; Girod, C.; Braillon, A.; Hadengue, A.; Lebrec, D.

    1986-08-01T23:59:59.000Z

    Systemic and splanchnic hemodynamics of the chronic bile duct-ligated rat were characterized by radioactive microspheres. Conscious and pentobarbital sodium-anesthetized, bile duct-ligated and sham-operated rats had cardiac output and regional organ blood flows determined. The conscious bile duct-ligated rat compared with the sham-operated showed a hyperdynamic circulation with an increased cardiac output and portal tributary blood flow. Pentobarbital sodium anesthesia induced marked hemodynamic changes in both sham-operated and bile duct-ligated rats. The latter group was especially sensitive to its effects; thus, comparison of cardiac output and portal tributary blood flow between anesthetized bile duct-ligated and sham-operated rats showed no significant differences. The authors conclude that the rat with cirrhosis due to chronic bile duct ligation is an excellent model for hemodynamic investigations but should be studied in the conscious state, since pentobarbital sodium anesthesia eliminated the hyperdynamic circulation.

  13. Q. For the 2005 Standards there is a new compliance credit for "ducts buried in attic insulation." What must be done to qualify for that credit?

    E-Print Network [OSTI]

    Q. For the 2005 Standards there is a new compliance credit for "ducts buried in attic insulation installation of insulation and duct sealing. When taking the buried duct credit, a minimum of R-30 insulation-4.2 duct insulation. Only the portions of duct runs that are directly on or within 3.5 inches

  14. Comparative Study: CFD ?P Versus Measured ?P for 30% Flexible Ducts

    E-Print Network [OSTI]

    Ugursal, A.; Culp, C.

    2006-01-01T23:59:59.000Z

    very close comparison with measured results. Flexible ducts can be installed in a variety of configurations with different compression. A configuration was specified for this study which focused on 30% compressed 5 foot-long flexible duct and 2... foot-long circular ducts placed on both ends. A CFD model was built and simulations were run under different volumetric air flows. The static pressure drop for those conditions were analyzed and displayed. The final CFD model is tuned until...

  15. DEVELOPING FLOW AND HEAT TRANSFER IN STRONGLY CURVED DUCTS OF RECTANGULAR CROSS-SECTION

    E-Print Network [OSTI]

    Yee, G.

    2010-01-01T23:59:59.000Z

    DEVELOpiNG FLOW AND HEAT TRANSFER IN STRONGLY CURVED DUCTS9092 Developing Flow and Heat Transfer in Strongly CurvedForced Convection Heat Transfer in Curved Rectangular

  16. Strati?ed shear ?ow: experiments in an inclined duct

    E-Print Network [OSTI]

    Meyer, Colin R.; Linden, P.F.

    2014-07-11T23:59:59.000Z

    is a fundamental problem in fluid mechanics with important implications across a wide diversity of applications from mixing in the oceans and atmosphere down to scales † Email address for correspondence: colinrmeyer@gmail.com. 2 C. R. Meyer and P. F... force produces a constant acceleration on each layer (Thorpe 1968) implying that U ? 2gAt sin ?. Over the time it takes for fluid to transit the duct t ? L/U this acceleration would produce a layer kinetic energy (per unit mass) U2 ? gAL sin ?...

  17. Duct Chase Sprinkler Replacement Project (4594), 5/31/2012

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power AdministrationField Campaign:INEA : Papers69ChristopherDrug-resistantEnergyDuct Chase

  18. Report of IAU Commission 30 on Radial Velocities (2009-2012)

    E-Print Network [OSTI]

    Torres, G; Lovis, C; Marcy, G W; Mathieu, R D; Mazeh, T; Meibom, S; Minniti, D; Moutou, C; Pepe, F; Pourbaix, D; Turon, C; Udry, S; Zwitter, T

    2011-01-01T23:59:59.000Z

    Brief summaries are given of the following subjects of interest to IAU Commission 30: Large-scale radial-velocity surveys; The role of radial-velocity measurements in studies of stellar angular momentum evolution and stellar age; Radial velocities in open clusters; Toward higher radial-velocity precision; High-precision radial velocities applied to studies of binary stars; Doppler boosting effect; Working groups (Stellar radial velocity bibliography; Radial velocity standards; Catalogue of orbital elements of spectroscopic binaries [SB9]).

  19. Air-Side Energy Use Calculations for Four HVAC Systems: Dual Duct Constant Volume (DDCAV), Dual Duct Variable Volume (DDVAV), Constant Volume with Reheat (CAVRH0), Variable Volume with Reheat (VAVRH)

    E-Print Network [OSTI]

    Haberl, J. S.

    2001-01-01T23:59:59.000Z

    This report contains engineering calculations for four (4) air-side, heating, ventilating and air-conditioning systems (HVAC) systems, including: dual duct constant volume (DDCAV), dual duct variable volume (DDVAV), constant volume with reheat...

  20. Velocity pump reaction turbine

    DOE Patents [OSTI]

    House, Palmer A. (Walnut Creek, CA)

    1982-01-01T23:59:59.000Z

    An expanding hydraulic/two-phase velocity pump reaction turbine including a dual concentric rotor configuration with an inter-rotor annular flow channel in which the inner rotor is mechanically driven by the outer rotor. In another embodiment, the inner rotor is immobilized and provided with gas recovery ports on its outer surface by means of which gas in solution may be recovered. This velocity pump reaction turbine configuration is capable of potential energy conversion efficiencies of up to 70%, and is particularly suited for geothermal applications.

  1. Velocity pump reaction turbine

    DOE Patents [OSTI]

    House, Palmer A. (Walnut Creek, CA)

    1984-01-01T23:59:59.000Z

    An expanding hydraulic/two-phase velocity pump reaction turbine including a dual concentric rotor configuration with an inter-rotor annular flow channel in which the inner rotor is mechanically driven by the outer rotor. In another embodiment, the inner rotor is immobilized and provided with gas recovery ports on its outer surface by means of which gas in solution may be recovered. This velocity pump reaction turbine configuration is capable of potential energy conversion efficiencies of up to 70%, and is particularly suited for geothermal applications.

  2. Experimental validation of large eddy simulations of flow and heat transfer in a stationary ribbed duct

    E-Print Network [OSTI]

    Thole, Karen A.

    Elsevier Inc. All rights reserved. Keywords: Duct flow; Ribbed channels; LES 1. Introduction In an effortExperimental validation of large eddy simulations of flow and heat transfer in a stationary ribbed Abstract Accurate prediction of ribbed duct flow and heat transfer is of importance to the gas turbine

  3. Theoretical Modeling Issue in Active Noise Control for a One-Dimensional Acoustic Duct System

    E-Print Network [OSTI]

    Yang, Zhenyu

    Theoretical Modeling Issue in Active Noise Control for a One-Dimensional Acoustic Duct System-6700 Esbjerg, Denmark Email: yang,sp@aaue.dk Abstract--The theoretical modeling of active noise control for the entire one-dimensional active duct noise control system is obtained and validated. The developed model

  4. Sealing Ducts in Large Commercial Buildings with Aerosolized Sealant M. P. Modera, O. Brzozowski**

    E-Print Network [OSTI]

    LBNL-42414 1 Sealing Ducts in Large Commercial Buildings with Aerosolized Sealant Particles M. P buildings is on the order of 10 kWh/m2 per year (1 kWh/ft2 ). We have tested, in two large commercial technology is capable of sealing the leaks in a large commercial building duct system within a reasonable

  5. Interior Duct Wall Pressure Downstream of a Low-Speed Scott C. Morris

    E-Print Network [OSTI]

    Alonso, Juan J.

    Interior Duct Wall Pressure Downstream of a Low-Speed Rotor Scott C. Morris , David B. Stephens The region downstream of a ducted rotor has been experimentally investigated in terms of its wake the description of the flow field and wall pressure in the region downstream of the rotor. Measurements involving

  6. Seamless Handover in Buildings Using HVAC Ducts: A New System Architecture

    E-Print Network [OSTI]

    Stancil, Daniel D.

    Seamless Handover in Buildings Using HVAC Ducts: A New System Architecture Ariton E. Xhafa, Paisarn-- In this paper, we present an innovative solution to the handover problem in multi-story buildings using HVAC of the indoor wireless networks that use the heating, ventilation, and air conditioning (HVAC) ducts

  7. Multi-carrier Signal Transmission through HVAC Ducts: Experimental Results for Channel Capacity

    E-Print Network [OSTI]

    Stancil, Daniel D.

    Multi-carrier Signal Transmission through HVAC Ducts: Experimental Results for Channel Capacity, for the first time, experimental results on channel capacity of heating, ventilation, and air-conditioning (HVAC through a building HVAC duct system demonstrate the ability to transmit with a spectral efficiency of 3

  8. Ducted Turbine Blade Optimization Using Numerical Simulation Michael Shives and Curran Crawford

    E-Print Network [OSTI]

    Pedersen, Tom

    Ducted Turbine Blade Optimization Using Numerical Simulation Michael Shives and Curran Crawford analysis and optimization of ducted turbines. The model is similar to standard blade element momentum. This eliminates many assumptions used in applying the typical blade element momentum (BEM) theory to a turbine

  9. Study of instabilities and quasi-two-dimensional turbulence in volumetrically heated magnetohydrodynamic flows in a vertical rectangular duct

    E-Print Network [OSTI]

    Abdou, Mohamed

    magnetohydrodynamic flows in a vertical rectangular duct N. Vetcha, S. Smolentsev, M. Abdou, and R. Moreau Citation in a vertical rectangular duct N. Vetcha,1 S. Smolentsev,1,a) M. Abdou,1 and R. Moreau2 1 Mechanical

  10. IMPACT OF PRESSURE EQUALIZATION SLOT IN FLOW CHANNEL INSERT ON TRITIUM TRANSPORT IN A DCLL-TYPE POLOIDAL DUCT

    E-Print Network [OSTI]

    Abdou, Mohamed

    -TYPE POLOIDAL DUCT H. Zhang, A. Ying, M. Abdou Mechanical and Aerospace Engineering Dept., UCLA, Los Angeles, CA

  11. Pressure Losses in 12”, 15” and 16” Non-Metallic Flexible Ducts with Compression and Sag (RP-1333)

    E-Print Network [OSTI]

    Culp, C.H.; Cantrill, D.

    . This study contains the measure- ments and calculated parameters from 12” (305 mm), 14” (356 mm) and 16” (406 mm) non-metallic flexible duct with compression and sag between 24” (610 mm) joists. Prior measurements of pressure drop for flexible ducts were... pressure losses which are 2 to 13 times higher than sheetmetal ducts. Ugursal and Culp (2007) calculated pressure loss using computational fluid dynamics (CFD) (Fluent, 2004). Their results showed agreement with fully stretched flexible duct and 30...

  12. Design of an Overmoded-Waveguide Directional Antenna for Use in In-Building Ventilation Duct Wireless Networks

    E-Print Network [OSTI]

    Stancil, Daniel D.

    -to-design wireless net- works with better coverage is to use heating, ventilation, and air conditioning (HVAC) ductsDesign of an Overmoded-Waveguide Directional Antenna for Use in In-Building Ventilation Duct ventilation ducts. We obtain experimentally the element size and spacing of a reflector and driven element

  13. Microstructure Development during High-Velocity Deformation P.J. FERREIRA, J.B. VANDER SANDE, M. AMARAL FORTES, and A. KYROLAINEN

    E-Print Network [OSTI]

    Ferreira, Paulo J.

    industries. In the automotive industry, an understanding of the mechanisms occurring dur- ing high was observed without failure in iron, cop- per, and aluminum sheets)[1,2] as well as significant strain

  14. Device for temporarily closing duct-formers in well completion apparatus

    SciTech Connect (OSTI)

    Zandmer, H.M.; Zandmer, S.M.

    1981-08-25T23:59:59.000Z

    A duct-forming device is disclosed for use in a well completion apparatus of the kind, wherein a bore hole casing is positioned in a bore hole and duct-forming devices of alkali- and acid resistant metal-such as steel-are secured at spaced levels to the casing in alignment with holes machined in the casing wall. In accordance with the invention, a closure device is arranged within the duct-forming device which permits flow of predetermined amounts of liquid, such as acid, from the interior of the casing through the duct-forming device and into the producing formation, while gradually being moved by the liquid into a position in which such fluid flow is prevented. After the fluid flow has been stopped by the closure device and when the formation pressure exceeds the pressure within the duct-forming device and the casing, fluid from the formation then forces the closure device toward and into the casing space to permit thereafter free flow of formation fluid into the duct-forming device and the casing or of pressurized treatment liquid from the casing into the formation. The inventive arrangement permits inter alia the establishment of a sufficient and substantially uniform feeding rate of treatment liquid, such as acid, from the casing into the producing formation through all the duct-formers in preparation for subsequent acidification or other treatments, such as sand fracking.

  15. Qualification of Fan Generated Duct Rumble Noise: Part 1: Test Facility(RP 1219)

    E-Print Network [OSTI]

    Kading, J.; Mann, A.; Pate, M.B.

    the transition duct from break in noise from the fan room. The fiberglass insulation on the inside of the box was suspended against the MDF in order to limit any vibration damping that might occur if the insula- tion touched the duct. The duct work continued... mounted to a base. The mounting base was a double steel strut that held the fan and motor assemble together. The mounting base had six vibration isolation springs that it supported by. The four corner springs were 800 lb, 1” isolation springs, the middle...

  16. Investigation of wall friction in noncircular ducts with a rough liner

    E-Print Network [OSTI]

    Tyler, John Charles

    1959-01-01T23:59:59.000Z

    section Density Viscosity Dimensions L5/Q L/Q m/L& m/LQ 1. The friction factors, Reynolds numbers, and. abso- lute roughnesses for fluid flow in ducts having a glass fiber liner have been calculated and plotted in the form of characteristic... distributed, it is essential that the wall friction phenomena associated with the particular duct design be understood. When fluid is passed through a duct, a static pressure drop occurs due to the friction forces which act between the fluid. particles...

  17. Performance and Impact from Duct Repair and Ventilation Modifications of Two Newly Constructed Manufactured Houses Located in a Hot and Humid Climate

    E-Print Network [OSTI]

    Withers, C.; Moyer, N.; Chasar, D.; Chandra, S.

    2002-01-01T23:59:59.000Z

    airtightness was adjusted until it was the same in each house, and duct leaks were sealed so that the ducts were tight and there was equal tightness in both houses. A ventilation system was also added at the same time of duct repair. Duct repair...

  18. Terminal Velocity Infall in QSO Absorption Line Halos

    E-Print Network [OSTI]

    Robert A. Benjamin

    1998-11-04T23:59:59.000Z

    We explore the hypothesis that clouds detected in quasar absorption line systems are falling at a terminal velocity toward the center of high redshift gaseous galactic halos. Since both the ionization level and terminal velocity of halo clouds increase with increasing distance from the central galaxy, velocity resolved profiles of highly ionized gas are predicted to have a greater width than low ionization gas. A line of sight passing through the center of gaseous halo (an idealized damped Ly alpha system), yields low ionization absorption at the velocity of the galaxy, flanked by high ionization on either side. Reasonable halo parameters yield total velocity extents for C IV of v_{C IV}=100-200 km/s, in agreement with several observed systems. The remaining systems may better described by the rotating disk model of Prochaska & Wolfe (1998). Finally, observational tests are suggested for verifying or falsifying the terminal velocity hypothesis for these systems.

  19. Inspection, Assessment, and Repair of Grouted Ducts in Post-tensioned Bridge 

    E-Print Network [OSTI]

    Im, Seok Been

    2011-02-22T23:59:59.000Z

    Segmental post-tensioned (PT) bridges are major structures that carry significant traffic. Recent investigations of these bridges have identified voids in their ducts. and some of these exposed strands at these void locations ...

  20. Comparative Analysis of CFD ?P vs. Measured ?P for Compressed Flexible Ducts

    E-Print Network [OSTI]

    Ugursal, A.; Culp, C.H.

    Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Comparative Analysis of CFD [Delta]P vs. Measured [Delta]P for Compressed Flexible Ducts Ugursal, Ahmet;Culp, Charles ASHRAE Transactions; 2007...

  1. An Experimental Evaluation of Duct-Mounted Relative Humidity Sensors: Part 2 – Accuracy Results 

    E-Print Network [OSTI]

    Joshi, S.N.; Pate, M.B.; Nelson, R.M; House, J.H.; Klaasen, C.J.

    2005-01-01T23:59:59.000Z

    Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. An Experimental Evaluation of Duct-Mounted Relative Humidity Sensors: Part 2-Accuracy Results Joshi, Shailesh N;House, John M;Pate, Michael B...

  2. An Experimental Evaluation of Duct-Mounted Relative Humidity Sensors: Part 1 – Test and Evaluation Procedures 

    E-Print Network [OSTI]

    Joshi, S.N.; Pate, M.B.; Nelson, R.M.; House, R.H.; Klaasen, C.J.

    2005-01-01T23:59:59.000Z

    Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. An Experimental Evaluation of Duct-Mounted Relative Humidity Sensors: Part 1, Test and Evaluation... Joshi, Shailesh N;Pate, Michael B...

  3. Observations on the Anterior Testicular Ducts in Snakes With Emphasis on Sea Snakes and

    E-Print Network [OSTI]

    Sever, David M.

    and Ultrastructure in the Yellow-Bellied Sea Snake, Pelamis platurus David M. Sever* and Layla R. Freeborn Department, Pelamis platurus, only the third such study on snakes. The anterior testicular ducts are similar in his

  4. Turbulent mixing in ducts, theory and experiment application to aerosol single point sampling

    E-Print Network [OSTI]

    Langari, Abdolreza

    1997-01-01T23:59:59.000Z

    The Environmental Protection Agency (EPA) has announced rules for continuous emissions monitoring (CEM) of stacks and ducts in nuclear facilities. EPA has recently approved use of Alternative Reference Methodologies (ARM) for air sampling in nuclear...

  5. Particle image velocimetry in an advanced, serpentine jet engine inlet duct

    E-Print Network [OSTI]

    Tichenor, Nathan Ryan

    2009-05-15T23:59:59.000Z

    The overarching objective of this research project was to gain improved basic understanding of the fluid mechanisms governing the development of secondary flow structures in complex, three-dimensional inlet ducts. To accomplish this objective...

  6. Control Humidity With Single-Duct, Single-Zone, Constant Air Volume System

    E-Print Network [OSTI]

    Chen, H.; Deng, S.; Bruner, H. L.; Claridge, D. E.

    2000-01-01T23:59:59.000Z

    ), which turned this inefficient, humid lecture hall into a comfortable learning environment. This case study also explores other possibilities to solve the humidity control problem with single-duct, single-zone constant air volume systems....

  7. Static Pressure Losses in 6 in., 8 in., and 10 in. Nonmetallic Flexible Duct (RP-1333)

    E-Print Network [OSTI]

    Weaver, K.; Culp, C.H.

    Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Static Pressure Losses in Nonmetallic Flexible Duct Weaver, Kevin;Culp, Charles ASHRAE Transactions; 2007; 113, ProQuest pg. 400 Reproduced...

  8. Integrated Demand Controlled Ventilation for Single Duct VAV System with Conference Rooms

    E-Print Network [OSTI]

    Yu, Y.; Liu, M.; Cho, Y.; Xu, K.

    2007-01-01T23:59:59.000Z

    Single duct variable air volume (VAV) systems are widely used in office buildings to achieve energy savings. It supplies proper amount of conditioned air to satisfy both the load and the ventilation requirements of each individual zone. To obtain...

  9. Augmentation of Power Output of Axisymmetric Ducted Wind Turbines by Porous Trailing Edge Disks

    E-Print Network [OSTI]

    widnall, sheila

    2014-06-30T23:59:59.000Z

    This paper presents analytical and experimental results that demonstrated that the power output from a ducted wind turbine can be dramatically increased by the addition of a trailing edge device such as a porous disk. In ...

  10. Optimization of supply air temperature reset schedule for a single duct VAV systems

    E-Print Network [OSTI]

    Fan, Wenshu

    2009-05-15T23:59:59.000Z

    In a single duct variable air volume (SDVAV) system, the supply air temperature is usually set as a constant value. Since this constant setpoint is selected to satisfy the maximum cooling load conditions, significant reheat will occur once...

  11. Continuous Commissioning® of a Single Fan Dual Duct System in an Office Building 

    E-Print Network [OSTI]

    Dong, D.; Liu, M.

    2005-01-01T23:59:59.000Z

    The building has a total of 216 dual duct independent terminal boxes with air flow stations. The boxes are used for both interior and exterior zones. Pneumatic controllers and actuators are installed. A dual-duct single fan AHU serves the building... the setting. OPTIMAL CONTROL SCHEDULES The control schedule optimization includes terminal boxes, AHU, chillers, and boilers. All the pneumatic controls for the AHU system, except box controllers, are updated to DDC controls before the optimal...

  12. Continuous Commissioning® of a Single Fan Dual Duct System in an Office Building

    E-Print Network [OSTI]

    Dong, D.; Liu, M.

    2005-01-01T23:59:59.000Z

    in this case include installing VFD on the supply fan and return fan, updating all terminal boxes from CAV modes into VAV modes, resetting duct static pressure and supply air temperature, optimizing outside air intake and installing VFDs on chiller... are introduced in this paper. The technologies involve dual duct static pressure reset control, outside air intake in the morning, variable chilled water system control, and variable hot water system control. ESL-IC-10/05-15 1 CC ® has been achieving...

  13. Apparatus and method for laser velocity interferometry

    DOE Patents [OSTI]

    Stanton, Philip L. (Bernalillo County, NM); Sweatt, William C. (Albuquerque, NM); Crump, Jr., O. B. (Albuquerque, NM); Bonzon, Lloyd L. (Albuquerque, NM)

    1993-09-14T23:59:59.000Z

    An apparatus and method for laser velocity interferometry employing a fixed interferometer cavity and delay element. The invention permits rapid construction of interferometers that may be operated by those non-skilled in the art, that have high image quality with no drift or loss of contrast, and that have long-term stability even without shock isolation of the cavity.

  14. Seminole Electric FGD study reveals corrosion mechanisms, duct material performance

    SciTech Connect (OSTI)

    Wess, T.J.; Crum, J.R.; Shoemaker, L.E.

    1994-12-01T23:59:59.000Z

    This article describes how once the corrosion rates of the materials used in the construction of scrubbers are known, specifying for longevity becomes an easier task. To properly evaluate the corrosion resistance of the materials used to fabricate the ducts, dampers, structural supports and other elements of a particular system, a testing scheme that systematically exposes material samples to the many environments representing areas of varying corrosivity is ideal. Because the exact composition, pH, and temperature of liquids and vapors in these areas are usually not known, gathering and analyzing samples of these elements is a prudent part of a systems' evaluation. Field testing of this type was conducted at the Seminole Generating Station which consists of two 650-MW coal-fired electric generating units that typically burn western Kentucky and eastern Illinois sub-bituminous coal with a sulfur content up to 3% and a 0.2%--0.3% chloride content. The plant has a typical wet limestone FGD system that sprays a solution of crushed limestone downward in a vertical rubber-lined scrubber module against a rising flue gas flow stream. There are five parallel scrubber modules available and a direct chimney bypass line that is used only during start up or during emergency conditions. Specially-welded test panels containing four different alloys and two weld filler metals were used in the field tests.

  15. Building America Case Study: Duct in Conditioned Space in a Dropped Ceiling or Fur-down, Gainesville, Florida (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2014-09-01T23:59:59.000Z

    Forced air distribution systems (duct systems) typically are installed out of sight for aesthetic reasons, most often in unconditioned areas such as an attic or crawlspace. Any leakage of air to or from the duct system (duct leakage) in unconditioned space not only loses energy, but impacts home and equipment durability and indoor air quality. An obvious solution to this problem is to bring the duct system into the interior of the house, either by sealing the area where the ducts are installed (sealed attic or crawlspace) or by building an interior cavity or chase above the ceiling plane (raised ceiling or fur-up chase) or below the ceiling plane (dropped ceiling or fur-down) for the duct system. This case study examines one Building America builder partner's implementation of an inexpensive, quick and effective method of building a fur-down or dropped ceiling chase.

  16. Velocity Dispersions Across Bulge Types

    SciTech Connect (OSTI)

    Fabricius, Maximilian; Bender, Ralf; Hopp, Ulrich [University Observatory of the Ludwig-Maximilians University (LMU) (Germany); Max-Planck Institute for Extraterrestrial Physics (MPE) (Germany); Saglia, Roberto; Drory, Niv [Max-Planck Institute for Extraterrestrial Physics (MPE) (Germany); Fisher, David [Department of Astronomy, University of Texas at Austin (United States)

    2010-06-08T23:59:59.000Z

    We present first results from a long-slit spectroscopic survey of bulge kinematics in local spiral galaxies. Our optical spectra were obtained at the Hobby-Eberly Telescope with the LRS spectrograph and have a velocity resolution of 45 km/s (sigma*), which allows us to resolve the velocity dispersions in the bulge regions of most objects in our sample. We find that the velocity dispersion profiles in morphological classical bulge galaxies are always centrally peaked while the velocity dispersion of morphologically disk-like bulges stays relatively flat towards the center--once strongly barred galaxies are discarded.

  17. Is there Lower Limit to Velocity or Velocity Change?

    E-Print Network [OSTI]

    B. N. Sreenath; Kenath Arun; C. Sivaram

    2013-06-19T23:59:59.000Z

    Here we explore the possibility of a lower limit to velocity or velocity change which is 20 orders of magnitude smaller than the speed of light and explore the various observable signatures including those in cosmic rays and gamma ray bursts.

  18. Comparative Testing of the Combined Radiant Barrier and Duct Models in the ESL's Code-Compliant Simulation Model

    E-Print Network [OSTI]

    Kim, S.; Haberl, J. S.

    2007-07-10T23:59:59.000Z

    level. Significant differences in the return duct leakage calculations were observed. These comparisons show the ESL model is more sensitive to return duct leakage than the EnergyGauge model Comparison of the results of the duct model for two... ? ?= ) 60 exp( rpine r r RCQ A B ? ?= tamb,r tamb,s se s s QQ Q a ? = re r r QQ Q a ? = in t sp t Figure 7. Schematic diagram of duct model based on ASHRAE 152-2004. The following equations show the procedure for calculating the delivery efficiency...

  19. Note: A helical velocity selector for continuous molecular beams

    SciTech Connect (OSTI)

    Szewc, Carola; Collier, James D.; Ulbricht, Hendrik [School of Physics and Astronomy, University of Southampton, Highfield, SO17 1BJ (United Kingdom)

    2010-10-15T23:59:59.000Z

    We report on a modern realization of the classic helical velocity selector for gas phase particle beams. The device operates stably under high vacuum conditions at rotational frequencies limited only by commercial dc motor capabilities. Tuning the rotational frequency allows selective scanning over a broad velocity band. The width of the selected velocity distributions at full-width-half-maximum is as narrow as a few percent of the selected mean velocity and independent of the rotational speed of the selector. The selector generates low vibrational noise amplitudes comparable to mechanically damped state-of-the-art turbo-molecular pumps and is therefore compatible with vibration sensitive experiments like molecule interferometry.

  20. Peristaltic flow of a fluid in a porous channel: A study having relevance to flow of bile within ducts in a pathological state

    E-Print Network [OSTI]

    S Maiti; J. C. Misra

    2011-07-28T23:59:59.000Z

    The paper deals with a theoretical study of the transport of a fluid in a channel, which takes place by the phenomenon of peristalsis. A mathematical analysis of the said problem has been presented. The analysis involves the application of a suitable perturbation technique. The velocity profile and the critical pressure for the occurrence of reflux are investigated with particular emphasis by using appropriate numerical methods. The effects of various parameters, such as Reynolds number, pressure gradient, porosity parameter, Darcy number, slip parameter, amplitude ratio and wave number on velocity and critical pressure for reflux are investigated in detail. The computed results are compared with a previous analytical work and an experimental investigation reported earlier in existing scientific literatures. The results of the present study are in conformity to both of them. The study has got some relevance to the physiological flow of bile in the common bile duct in a pathological state. It reveals that in the presence of gallstones, bile velocity increases as the value of the porosity parameter increases, while the critical pressure for reflux decreases as porosity increases.

  1. Scaleup tests and supporting research for the development of duct injection technology

    SciTech Connect (OSTI)

    Gooch, J.P.; Dismukes, E.B.; Dahlin, R.S.; Faulkner, M.G. (Southern Research Inst., Birmingham, AL (United States)); Klett, M.G.; Buchanan, T.L.; Hunt, J.E. (Gilbert/Commonwealth, Inc., Reading, PA (United States))

    1989-05-01T23:59:59.000Z

    Gilbert Commonwealth, Southern Research Institute and the American Electric Power Service Corporation have embarked on a program to convert DOE's Duct Injection Test Facility located at the Muskingum River Power Plant of Ohio Power Company to test alternate duct injection technologies. The technologies to be tested include slurry sorbent injection of hydrated lime using dual fluid nozzles, or a rotary atomizer and pneumatic injection of hydrated lime, with flue gas humidification before or after sorbent injection. The literature review and analysis contained in this report is a part of the preparatory effort for the test program.

  2. Heat transfer and pressure drop in square duct with two opposite repeated rib-roughened walls

    E-Print Network [OSTI]

    Lei, Chiang-Kuo

    1983-01-01T23:59:59.000Z

    were on ribbed sur- faces. All thermocouples were constructed of 0. 05 cm copper-constantant wire. Five pressure taps along the test section were used for the static pressure drop measurements across the test duct. Three were on the smooth surface...HEAT TRANSFER AND PRESSURE DROP IN SQUARE DUCT WITH TWO OPPOSITE REPEATED RIB-ROUGHENED WALLS A Thesis CHIANG-KUO LEI Submitted to the Graduate College of Texas ARM University in partial fulfillment of the requirement for the degree of MASTER...

  3. Electric coheating as a means to test duct efficiency: A review and analysis of the literature

    SciTech Connect (OSTI)

    Andrews, J.W.

    1995-08-01T23:59:59.000Z

    Recent published literature on electric coheating was reviewed in order to assess its suitability for use in a method of test for the efficiency of residential duct systems. Electric coheating is the research use of electric heaters within the heated space to assess the thermal integrity of the building envelope. Information was sought in two primary areas: (1) experimental methodology and (2) accuracy of the coheating method. A variety of experimental variations was found, and the method was judged, on the basis of published data, to be capable of sufficient accuracy for use in duct testing.

  4. Numerical Analysis of Turbine Blade Cooling Ducts M.J. Noot and R.M.M. Mattheij

    E-Print Network [OSTI]

    Eindhoven, Technische Universiteit

    Numerical Analysis of Turbine Blade Cooling Ducts M.J. Noot and R.M.M. Mattheij Eindhoven, The Netherlands March 2, 1998 Abstract The cooling of turbine blades in turbines is enhanced by providing the quality of these cooling ducts. 1 Introduction Gas turbines play an important role in aviation

  5. Wireless RF Distribution in Buildings using Heating and Ventilation Ducts Christopher P. Diehl, Benjamin E. Henty, Nikhil Kanodia, and Daniel D. Stancil

    E-Print Network [OSTI]

    Stancil, Daniel D.

    Wireless RF Distribution in Buildings using Heating and Ventilation Ducts Christopher P. Diehl in buildings is proposed in which the heating and ventilation ducts are used as waveguides. Because

  6. Line bisectors and radial velocity jitter from SARG spectra

    E-Print Network [OSTI]

    A. F. Martinez Fiorenzano; R. G. Gratton; S. Desidera; R. Cosentino; M. Endl

    2005-08-03T23:59:59.000Z

    We present an analysis of spectral line bisector variations for a few stars observed in the SARG high precision radial velocity planet survey, and discuss their relationship with differential radial velocities. The spectra we consider are the same used for determining radial velocities. The iodine cell lines employed in the measurement of radial velocities were removed before bisector analysis. The line bisectors were then computed from average absorption profiles obtained by cross correlation of the stellar spectra with a mask made from suitable lines of a solar catalog. Bisector velocity spans were then determined: errors in these quantities compare well with theoretical expectations based on resolution, S/N and line shape. The plot of bisector velocity span against radial velocity was studied to search for correlations between line asymmetries and radial velocity variations. A correlation was seen for HD 166435 due to stellar activity, and for HD 8071B due to spectral contamination by the companion. No correlation was seen for 51 Peg and rho CrB, stars hosting planets. We conclude that this technique may be useful to separate radial velocity variations due to barycenter motion from spurious signals in spectra acquired with the iodine cell.

  7. GMTI radar minimum detectable velocity.

    SciTech Connect (OSTI)

    Richards, John Alfred

    2011-04-01T23:59:59.000Z

    Minimum detectable velocity (MDV) is a fundamental consideration for the design, implementation, and exploitation of ground moving-target indication (GMTI) radar imaging modes. All single-phase-center air-to-ground radars are characterized by an MDV, or a minimum radial velocity below which motion of a discrete nonstationary target is indistinguishable from the relative motion between the platform and the ground. Targets with radial velocities less than MDV are typically overwhelmed by endoclutter ground returns, and are thus not generally detectable. Targets with radial velocities greater than MDV typically produce distinct returns falling outside of the endoclutter ground returns, and are thus generally discernible using straightforward detection algorithms. This document provides a straightforward derivation of MDV for an air-to-ground single-phase-center GMTI radar operating in an arbitrary geometry.

  8. Robust optimization of a 2D air conditioning duct using kriging Deliverable WP.2.2.2.B of the ANR / OMD2 project

    E-Print Network [OSTI]

    Boyer, Edmond

    Robust optimization of a 2D air conditioning duct using kriging Deliverable WP.2.2.2.B of the ANR optimization of a 2D air conditioning duct. For comparison purposes, deterministic designs were first obtained air conditioning duct. The uncertainties affect the pipe shape. The mean response, expressed in terms

  9. IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, VOL. 51, NO. 5, MAY 2003 945 Propagation Model for the HVAC Duct as a

    E-Print Network [OSTI]

    Stancil, Daniel D.

    for the HVAC Duct as a Communication Channel Pavel V. Nikitin, Member, IEEE, Daniel D. Stancil, Senior Member (HVAC) ducts in buildings are typically hollow metal pipes which can be used as waveguides to carry such a communication system. This paper presents a propagation model for a straight HVAC duct terminated at both ends

  10. A 12-MW-scale pilot study of in-duct scrubbing (IDS) using a rotary atomizer

    SciTech Connect (OSTI)

    Samuel, E.A.; Murphy, K.R.; Demian, A.

    1989-11-01T23:59:59.000Z

    A low-cost, moderate-removal efficiency, flue gas desulfurization (FGD) technology was selected by the US Department of Energy for pilot demonstration in its Acid Rain Precursor Control Technology Initiative. The process, identified as In-Duct Scrubbing (IDS), applies rotary atomizer techniques developed for lime-based spray dryer FGD while utilizing existing flue gas ductwork and particulate collectors. IDS technology is anticipated to result in a dry desulfurization process with a moderate removal efficiency (50% or greater) for high-sulfur coal-fired boilers. The critical elements for successful application are: (1) adequate mixing of sorbent droplets with flue gas for efficient reaction contact, (2) sufficient residence time to produce a non-wetting product, and (3) appropriate ductwork cross-sectional area to prevent deposition of wet reaction products before particle drying is comple. The ductwork in many older plants, previously modified to meet 1970 Clean Air Act requirements for particulate control, usually meet these criteria. A 12 MW-scale IDS pilot plant was constructed at the Muskingum River Plant of the American Electric Power System. The pilot plant, which operates from a slipstrem attached to the air-preheater outlet duct from the Unit 5 boiler at the Muskingum River Plant (which burns about 4% sulfur coal), is equipped with three atomizer stations to test the IDS concept in vertical and horizontal configurations. In addition, the pilot plant is equipped to test the effect of injecting IDS off- product upstream of the atomizer, on SO{sub 2}and NO{sub x} removals.

  11. LBNL# 40102 Field Investigation of Duct System Performance in California Light Commercial Buildings 1 of 26

    E-Print Network [OSTI]

    -top units and their associated ductwork. These simple systems use similar duct materials and construction, restaurants and professional buildings. First-cost dominates construction practices in these buildings. This potentially leads to short-cuts in construction practices and/or using lower grade materials. Often resulting

  12. Duct System Flammability and Air Sealing Fire Separation Assemblies in the International Residential Code

    SciTech Connect (OSTI)

    Rudd, A.; Prahl, D.

    2014-12-01T23:59:59.000Z

    IBACOS identified two barriers that limit the ability of builders to cost-effectively achieve higher energy efficiency levels in housing. These are (1) the use of duct system materials that inherently achieve airtightness and are appropriately sized for low-load houses and (2) the ability to air seal fire separation assemblies. The issues identified fall into a gray area of the codes.

  13. A Well-Balanced Scheme For Two-Fluid Flows In Variable Cross-Section ducts

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    , ) p = p(, s, ), h = h(, s, ). (21) Then in these variables the sound speed c satisfies c2 = p = h. (22 of a mixture of two compressible fluids (a gas (1) and a liquid (2), for instance) in a cross-section duct

  14. Development of an ASHRAE 152-2004 Duct Model for the Single-Family Residential House

    E-Print Network [OSTI]

    Kim, S.; Haberl, J.

    This paper presents the results of the development of the duct model based on ASHRAE standard 152-2004 (ASHRAE, 2004) using the DOE-2.1e building energy simulation program. To accomplish this, FUNCTION commands for DOE-2 were used to develop...

  15. Nonlinear self-excited thermoacoustic oscillations of a ducted premixed flame: bifurcations and routes to chaos

    E-Print Network [OSTI]

    Kashinath, Karthik; Waugh, Iain C.; Juniper, Matthew P.

    2014-01-01T23:59:59.000Z

    Thermoacoustic systems can oscillate self-excitedly, and often non-periodically, due to coupling between unsteady heat release and acoustic waves. We study a slot-stabilized two-dimensional premixed flame in a duct via numerical simulations of a G...

  16. ASU nitrogen sweep gas in hydrogen separation membrane for production of HRSG duct burner fuel

    DOE Patents [OSTI]

    Panuccio, Gregory J.; Raybold, Troy M.; Jamal, Agil; Drnevich, Raymond Francis

    2013-04-02T23:59:59.000Z

    The present invention relates to the use of low pressure N2 from an air separation unit (ASU) for use as a sweep gas in a hydrogen transport membrane (HTM) to increase syngas H2 recovery and make a near-atmospheric pressure (less than or equal to about 25 psia) fuel for supplemental firing in the heat recovery steam generator (HRSG) duct burner.

  17. Global evaluation of mass transfer effects: In-duct injection flue gas desulfurization

    SciTech Connect (OSTI)

    Cole, J.A.; Newton, G.H.; Kramlich, J.C.; Payne, R.

    1990-09-30T23:59:59.000Z

    Sorbent injection is a low capital cost, low operating cost approach to SO{sub 2} control targeted primarily at older boilers for which conventional fuel gas desulfurization is not economically viable. Duct injection is one variation of this concept in which the sorbent, either a dry powder or a slurry, is injected into the cooler regions of the boiler, generally downstream of the air heaters. The attractiveness of duct injection is tied to the fact that it avoids much of the boiler heat transfer equipment and thus has minimal impact of boiler performance. Both capital and operating cost are low. This program has as its objectives three performance related issues to address: (1) experimentally identify limits on sorbent performance. (2) identify and test sorbent performance enhancement strategies. (3) develop a compute model of the duct injection process. Two major tasks are described: a laboratory-scale global experiment and development of process model. Both are aimed at understanding and quantifying the rate-limiting processes which control SO{sub 2} capture by lime slurry during boiler duct injection. 29 refs., 35 figs., 4 tabs.

  18. 1 | Building America eere.energy.gov Evaluation of Ducted GE

    E-Print Network [OSTI]

    : ­ Impact on space conditioning energy consumption and occupant comfort. ­ Impact on demand response space in a number of configurations and as a demand response asset. · This information is necessary1 | Building America eere.energy.gov Evaluation of Ducted GE Hybrid Heat Pump Water Heater in PNNL

  19. Velocity requirements for causality violation

    E-Print Network [OSTI]

    Giovanni Modanese

    2015-01-18T23:59:59.000Z

    We re-examine the "Regge-Tolman paradox" with reference to some recent experimental results. It is straightforward to find a formula for the velocity v of the moving system required to produce causality violation. This formula typically yields a velocity very close to the speed of light (for instance, v/c > 0.97 for X-shaped microwaves), which raises some doubts about the real physical observability of the violations. We then compute the velocity requirement introducing a delay between the reception of the primary signal and the emission of the secondary. It turns out that in principle for any delay it is possible to find moving observers able to produce active causal violation. This is mathematically due to the singularity of the Lorentz transformations for beta to 1. For a realistic delay due to the propagation of a luminal precursor, we find that causality violations in the reported experiments are still more unlikely (v/c > 0.989), and even in the hypothesis that the superluminal propagation velocity goes to infinity, the velocity requirement is bounded by v/c > 0.62. We also prove that if two macroscopic bodies exchange energy and momentum through superluminal signals, then the swap of signal source and target is incompatible with the Lorentz transformations; therefore it is not possible to distinguish between source and target, even with reference to a definite reference frame.

  20. 3D Velocity from 3D Doppler Radial Velocity J. L. Barron,1

    E-Print Network [OSTI]

    Barron, John

    to compute local 3D velocity (local 3D optical flow). Radial velocity (measured by the Doppler effect3D Velocity from 3D Doppler Radial Velocity J. L. Barron,1 R. E. Mercer,1 X. Chen,1 P. Joe2 1 velocity data and qualitatively on real radial velocity data, obtained from the Doppler radar at Kurnell

  1. Low Velocity Boron Micro-Pellet Injector For Edge And Core Impurity Transport Measurements

    E-Print Network [OSTI]

    1 Low Velocity Boron Micro-Pellet Injector For Edge And Core Impurity Transport Measurements H. W, Baltimore, Maryland 21218 Abstract A simple Low Velocity Boron Micro-Pellet Injector has been under High velocity, pneumatic, pellet injection systems are applied routinely for injecting frozen pellets

  2. Radial velocities of southern visual multiple stars

    SciTech Connect (OSTI)

    Tokovinin, Andrei [Cerro Tololo Inter-American Observatory, Casilla 603, La Serena (Chile); Pribulla, Theodor [Astronomical Institute, Slovak Academy of Sciences, 059 60 Tatranská Lomnica (Slovakia); Fischer, Debra, E-mail: atokovinin@ctio.noao.edu, E-mail: pribulla@ta3.sk, E-mail: debra.fischer@gmail.com [Department of Astronomy, Yale University, New Haven, CT 06511 (United States)

    2015-01-01T23:59:59.000Z

    High-resolution spectra of visual multiple stars were taken in 2008–2009 to detect or confirm spectroscopic subsystems and to determine their orbits. Radial velocities of 93 late-type stars belonging to visual multiple systems were measured by numerical cross-correlation. We provide the individual velocities, the width, and the amplitude of the Gaussians that approximate the correlations. The new information on the multiple systems resulting from these data is discussed. We discovered double-lined binaries in HD 41742B, HD 56593C, and HD 122613AB, confirmed several other known subsystems, and constrained the existence of subsystems in some visual binaries where both components turned out to have similar velocities. The orbits of double-lined subsystems with periods of 148 and 13 days are computed for HD 104471 Aa,Ab and HD 210349 Aa,Ab, respectively. We estimate individual magnitudes and masses of the components in these triple systems and update the outer orbit of HD 104471 AB.

  3. CO and IRAS detection of an intermediate-velocity cloud

    SciTech Connect (OSTI)

    Desert, F.X.; Bazell, D.; Blitz, L. (Paris Observatoire, Meudon (France) Space Telescope Science Institute, Baltimore, MD (USA) Maryland Univ., College Park (USA))

    1990-06-01T23:59:59.000Z

    In the course of a radio survey of high-Galactic-latitude clouds, CO emission was detected at the position l = 210.8 deg and b = 63.1 deg with an LSR velocity of -39 km/sec. This molecular cloud constitutes the third one with an unusually large absolute velocity at these latitudes, as compared with the 5.4-km/sec cloud-to-cloud velocity dispersion of the high-latitude molecular clouds. The position is coincident with an H I intermediate-velocity cloud (GHL 11, Verschuur H, OLM 268) and the IR-excess cloud 306 in the list by Desert et al. (1988). This cloud is clearly detected at all four IRAS wavelengths and has warmer colors than the local ISM. 27 refs.

  4. Air-Side Energy Use Calculations for Four HVAC Systems: Dual Duct Constant Volume (DDCAV), Dual Duct Variable Volume (DDVAV), Constant Volume with Reheat (CAVRH), Variable Volume with Reheat (VAVRH), Four Pipe Fan Coil Unit (FC), Four Pipe Induction Unit (FI), and Single Zone (SZ) Systems, Revised June 2002

    E-Print Network [OSTI]

    Haberl, J. S.; Bou-Saada, T. E.; Saman, N. F.

    2001-01-01T23:59:59.000Z

    This report contains engineering calculations for seven (7) air-side, heating, ventilating and air conditioning systems (HVAC) systems, including: dual duct constant volume (DDCAV), dual duct variable volume (DDVAV), constant volume with reheat...

  5. SHIP VELOCITY FIELDS , Lichuan Guib

    E-Print Network [OSTI]

    Gui, Lichuan

    directions. 1. Introduction Knowledge of flow around ships is important for design, model development, and computational fluid dynamics (CFD) validation. Historically, five-hole pitot probes have been used for measuring of multi-hole pitot and Laser-doppler systems, they both require measurement of ship velocity fields

  6. Velocity Distributions from Nonextensive Thermodynamics

    E-Print Network [OSTI]

    Eric I. Barnes; Liliya L. R. Williams; Arif Babul; Julianne J. Dalcanton

    2006-10-05T23:59:59.000Z

    There is no accepted mechanism that explains the equilibrium structures that form in collisionless cosmological N-body simulations. Recent work has identified nonextensive thermodynamics as an innovative approach to the problem. The distribution function that results from adopting this framework has the same form as for polytropes, but the polytropic index is now related to the degree of nonextensiveness. In particular, the nonextensive approach can mimic the equilibrium structure of dark matter density profiles found in simulations. We extend the investigation of this approach to the velocity structures expected from nonextensive thermodynamics. We find that the nonextensive and simulated N-body rms-velocity distributions do not match one another. The nonextensive rms-velocity profile is either monotonically decreasing or displays little radial variation, each of which disagrees with the rms-velocity distributions seen in simulations. We conclude that the currently discussed nonextensive models require further modifications in order to corroborate dark matter halo simulations. (adapted from TeX)

  7. Pore fluid effects on seismic velocity in anisotropic rocks

    SciTech Connect (OSTI)

    Mukerji, T.; Mavko, G. (Stanford Univ., CA (United States). Dept. of Geophysics)

    1994-02-01T23:59:59.000Z

    A simple new technique predicts the high- and low-frequency saturated velocities in anisotropic rocks entirely in terms of measurable dry rock properties without the need for idealized crack geometries. Measurements of dry velocity versus pressure and porosity versus pressure contain all of the necessary information for predicting the frequency-dependent effects of fluid saturation. Furthermore, these measurements automatically incorporate all pore interaction, so there is no limitation to low crack density. The velocities are found to depend on five key interrelated variables: frequency, the distribution of compliant crack-like porosity, the intrinsic or noncrack anisotropy, fluid viscosity and compressibility, and effective pressure. The sensitivity of velocities to saturation is generally greater at high frequencies than low frequencies. The magnitude of the differences from dry to saturated and from low frequency to high frequency is determined by the compliant or crack-like porosity. Predictions of saturated velocities based on dry data for sandstone and granite show that compressional velocities generally increase with saturation and with frequency. However, the degree of compressional wave anisotropy may either increase or decrease upon saturation depending on the crack distribution, the effective pressure, and the frequency at which the measurements are made. Shear-wave velocities can either increase or decrease with saturation, and the degree of anisotropy depends on the microstructure, pressure, and frequency. Consequently great care must be taken when interpreting observed velocity anisotropy for measurements at low frequencies, typical of in situ observations, will generally be different from those at high frequencies, typical of the laboratory.

  8. Impact of Codes on Potential PVC Duct System Solution

    Broader source: Energy.gov [DOE]

    This presentation was given at the Summer 2012 DOE Building America meeting on July 26, 2012, and addressed the question "Do codes and standards get in the way of high performance?"

  9. 1736 IEEE TRANSACTIONS ON COMMUNICATIONS, VOL. 51, NO. 10, OCTOBER 2003 Impulse Response of the HVAC Duct as a

    E-Print Network [OSTI]

    Hochberg, Michael

    Member, IEEE, and Dagfin Brodtkorb, Member, IEEE Abstract--Heating, ventilation, and air conditioning-area network (LAN). I. INTRODUCTION THE heating, ventilation, and air conditioning (HVAC) duct system in most

  10. An Experimental Evaluation of Duct-Mounted Relative Humidity Sensors: Part 3 – Repeatability, Hysteresis and Linearity Results 

    E-Print Network [OSTI]

    Joshi, S.N.; Pate, M.B.; Nelson, R.M.; House, J.H.; Klaassen, C.J.

    2005-01-01T23:59:59.000Z

    Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. An Experimental Evaluation of Duct-Mounted Relative Humidity Sensors: Part 3-Repeatability, Hyste... Joshi, Shailesh N;House, John M...

  11. Wednesday, 06 October, 2010 Contrasting the efficiency of radiation belt losses caused by ducted and non-1

    E-Print Network [OSTI]

    Otago, University of

    -ducted transmissions originating from NPM34 generated electron flux enhancements. While the waves originating from that the enhancements from NPM are at least 50 times smaller than those from NWC. This37 suggests that lower latitude

  12. Use of Statistical Approach to Design an Optimal Duct System for On-demand Industrial Exhaust Ventilation 

    E-Print Network [OSTI]

    Litomisky, A.

    2010-01-01T23:59:59.000Z

    This paper elaborates on how to use statistics to calculate optimal parameters (including duct diameters) of energy-efficient industrial ventilation systems. Based on the fan-law, on-demand ventilation can save up to 80% ...

  13. Evaluation of mixing downstream of tees in duct systems with respect to single point representative air sampling

    E-Print Network [OSTI]

    Kim, Taehong

    2003-01-01T23:59:59.000Z

    Air duct systems in nuclear facilities must meet the requirements of ANSI N13.1-1999 and the Environmental Protection Agency (EPA) that the exhaust airflow be monitored with continuous sampling in case of an accidental release of airborne...

  14. Application of an ASHRAE 152-2004 Duct Model for Simulating Code-Compliant 2000/2001 IECC Residences

    E-Print Network [OSTI]

    Haberl, J.S.; Kim, S.

    2010-01-01T23:59:59.000Z

    This paper presents the results of the application of the duct model based on ASHRAE 152-2004 - Method of Test for Determining the Design and Seasonal Efficiencies of Residential Thermal Distribution Systems (ASHRAE 2004) to the code compliant 2001...

  15. Use of Statistical Approach to Design an Optimal Duct System for On-demand Industrial Exhaust Ventilation

    E-Print Network [OSTI]

    Litomisky, A.

    2010-01-01T23:59:59.000Z

    This paper elaborates on how to use statistics to calculate optimal parameters (including duct diameters) of energy-efficient industrial ventilation systems. Based on the fan-law, on-demand ventilation can save up to 80% of electricity compared...

  16. Application of an ASHRAE 152-2004 Duct Model for Simulating Code-Compliant 2000/2001 IECC Residences 

    E-Print Network [OSTI]

    Haberl, J.S.; Kim, S.

    2010-01-01T23:59:59.000Z

    This paper presents the results of the application of the duct model based on ASHRAE 152-2004 - Method of Test for Determining the Design and Seasonal Efficiencies of Residential Thermal Distribution Systems (ASHRAE 2004) ...

  17. Method and apparatus for duct sealing using a clog-resistant insertable injector

    DOE Patents [OSTI]

    Wang, Duo (Albany, CA); Modera, Mark P. (Piedmont, CA)

    2007-01-02T23:59:59.000Z

    A clog-resistant injector spray nozzle allows relatively unobtrusive insertion through a small access aperture into existing ductwork in occupied buildings for atomized particulate sealing of a ductwork. The spray nozzle comprises an easily cleaned and easily replaced straight liquid tube whose liquid contents are principally propelled by a heated propellant gas, such as heated air. Heat transfer is minimized from the heated propellant gas to the liquid tube until they both exit the injector, thereby greatly reducing the likelihood of nozzle clogging. A method of duct sealing using particles driven by heated propellant gas is described, whereby duct-sealing operations become both faster, and commercially practicable in inhabited commercial and residential buildings.

  18. Reducing Thermal Losses and Gains With Buried and Encapsulated Ducts in Hot-Humid Climates

    SciTech Connect (OSTI)

    Shapiro, C.; Magee, A.; Zoeller, W.

    2013-02-01T23:59:59.000Z

    The Consortium for Advanced Residential Buildings (CARB) monitored three houses in Jacksonville, FL, to investigate the effectiveness of encapsulated and encapsulated/buried ducts in reducing thermal losses and gains from ductwork in unconditioned attics. Burying ductwork beneath loose-fill insulation has been identified as an effective method of reducing thermal losses and gains from ductwork in dry climates, but it is not applicable in humid climates where condensation may occur on the outside of the duct jacket. By encapsulating the ductwork in closed cell polyurethane foam (ccSPF) before burial beneath loose-fill mineral fiber insulation, the condensation potential may be reduced while increasing the R-value of the ductwork.

  19. Integrated Demand Controlled Ventilation for Single Duct VAV System with Conference Rooms 

    E-Print Network [OSTI]

    Yu, Y.; Liu, M.; Cho, Y.; Xu, K.

    2007-01-01T23:59:59.000Z

    INTEGRATED DEMAND CONTROLLED VENTILATION FOR SINGLE DUCT VAV SYSTEM WITH CONFERENCE ROOMS Yuebin Yu Mingsheng Liu YoungHum Cho Ke Xu Graduate Student Professor of Architectural Engineering, PhD, PE Graduate.... The total OA intake of IDCV is obtained with the occupancy time ratio considered. The real time distribution of the occupancy and un-occupancy doesn’t much influence the overall calculation. With the amount of OA intake and the local BIN data...

  20. A Smart Logic for Conference Room Terminal Box of Single Duct VAV System 

    E-Print Network [OSTI]

    Yu, Y.; Xu, K.; Cho, Y.; Liu, M.

    2007-01-01T23:59:59.000Z

    A SMART LOGIC FOR CONFERENCE ROOM TERMINAL BOX OF SINGLE DUCT VAV SYSTEM Yuebin Yu Ke Xu YoungHum Cho Mingsheng Liu Graduate Student Graduate Student Graduate Student Professor of Architectural... in the conference room. The detailed calculation example for the parameters and the energy saving performance analysis based on air modeling are given in the other paper (Yuebin Yu, et al. 2007). The main principles of the operation logic are stated as follows...

  1. BENCAP, LLC: CAPSULE VELOCITY TEST

    SciTech Connect (OSTI)

    Meidinger, Brian

    2005-09-07T23:59:59.000Z

    Ben Cap, LLC, has a technology that utilizes bebtonite to plug wells. The bentonite is encapsulated in a cardboard capsule, droped down to the bottom of the well where it is allowed to hydrate, causing the bentonite to expand and plug the well. This method of plugging a well is accepted in some, but not all states. This technology can save a significant amount of money when compared to cementing methods currently used to plug and abandon wells. The test objective was to obtain the terminal velocity of the capsule delivery system as it drops through a column of water in a wellbore. Once the terminal velocity is known, the bentonite swelling action can be timed not to begin swelling until it reaches the bottom of the well bore. The results of the test showed that an average speed of 8.93 plus or minus 0.12 ft/sec was achieved by the capsule as it was falling through a column of water. Plotting the data revealed a very linear function with the capsules achieving terminal velocity shortly after being released. The interference of the capsule impacting the casing was not readily apparent in any of the runs, but a siginal sampling anomaly was present in one run. Because the anomaly was so brief and not present in any of the other runs, no solid conclusions could be drawn. Additional testing would be required to determine the effects of capsules impacting a fluid level that is not at surface.

  2. Supersonic relative velocity effect on the baryonic acoustic oscillation measurements

    SciTech Connect (OSTI)

    Yoo, Jaiyul; Seljak, Uroš [Institute for Theoretical Physics, University of Zürich, CH-8057 Zürich (Switzerland); Dalal, Neal, E-mail: jyoo@physik.uzh.ch, E-mail: neal@cita.utoronto.ca, E-mail: seljak@physik.uzh.ch [Canadian Institute for Theoretical Astrophysics, University of Toronto, 60 St. George Street, Ontario, M5S 3H8 (Canada)

    2011-07-01T23:59:59.000Z

    We investigate the effect of supersonic relative velocities between baryons and dark matter, recently shown to arise generically at high redshift, on baryonic acoustic oscillation (BAO) measurements at low redshift. The amplitude of the relative velocity effect at low redshift is model-dependent, but can be parameterized by using an unknown bias. We find that if unaccounted, the relative velocity effect can shift the BAO peak position and bias estimates of the dark energy equation-of-state due to its non-smooth, out-of-phase oscillation structure around the BAO scale. Fortunately, the relative velocity effect can be easily modeled in constraining cosmological parameters without substantially inflating the error budget. We also demonstrate that the presence of the relative velocity effect gives rise to a unique signature in the galaxy bispectrum, which can be utilized to isolate this effect. Future dark energy surveys can accurately measure the relative velocity effect and subtract it from the power spectrum analysis to constrain dark energy models with high precision.

  3. Ducts Sealing Using Injected Spray Sealant, Raleigh, North Carolina (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2014-03-01T23:59:59.000Z

    In multifamily and attached buildings, traditional duct sealing methods are often impractical or costly and disruptive because of the difficulty in accessing leakage sites. In this project, two retrofit duct sealing techniques - manually-applied sealants and injecting a spray sealant, were implemented in several low-rise multi-unit buildings. An analysis on the cost and performance of the two methods are presented. Each method was used in twenty housing units: approximately half of each group of units are single story and the remainder two-story. Results show that duct leakage to the outside was reduced by an average of 59% through the use of manual methods, and by 90% in the units where the injected spray sealant was used. It was found that 73% of the leakage reduction in homes that were treated with injected spray sealant was attributable to the manual sealing done at boots, returns and the air handler. The cost of manually-applying sealant ranged from $275 to $511 per unit and for the injected spray sealant the cost was $700 per unit. Modeling suggests a simple payback of 2.2 years for manual sealing and 4.7 years for the injected spray sealant system. Utility bills were collected for one year before and after the retrofits. Utility bill analysis shows 14% and 16% energy savings using injected spray sealant system and hand sealing procedure respectively in heating season whereas in cooling season, energy savings using injected spray sealant system and hand sealing were both 16%.

  4. The Systemic Velocity of Eta Carinae

    E-Print Network [OSTI]

    Nathan Smith

    2004-06-23T23:59:59.000Z

    High-resolution spectra of molecular hydrogen in the Homunculus nebula allow for the first direct measurement of the systemic velocity of Eta Carinae. Near-infrared long-slit data for H2 1-0 S(1) lambda 21218 obtained with the Phoenix spectrometer on the Gemini South telescope give Vsys=-8.1pm1 km/s (heliocentric), or VLSR=-19.7pm1 km/s, from the average of the near and far sides of the Homunculus. This measurement considerably improves the precision for the value of -7pm10 km/s inferred from neighboring O-type stars in the Carina nebula. New near-infrared spectra also provide a high-resolution line profile of [Fe II] lambda 16435 emission from gas condensations known as the Weigelt objects without contamination from the central star, revealing a line shape with complex kinematic structure. Previously, uncertainty in the Weigelt knots' kinematics was dominated by the adopted systemic velocity of Eta Car.

  5. Effects of increasing tip velocity on wind turbine rotor design.

    SciTech Connect (OSTI)

    Resor, Brian Ray; Maniaci, David Charles; Berg, Jonathan Charles; Richards, Phillip William

    2014-05-01T23:59:59.000Z

    A reduction in cost of energy from wind is anticipated when maximum allowable tip velocity is allowed to increase. Rotor torque decreases as tip velocity increases and rotor size and power rating are held constant. Reduction in rotor torque yields a lighter weight gearbox, a decrease in the turbine cost, and an increase in the capacity for the turbine to deliver cost competitive electricity. The high speed rotor incurs costs attributable to rotor aero-acoustics and system loads. The increased loads of high speed rotors drive the sizing and cost of other components in the system. Rotor, drivetrain, and tower designs at 80 m/s maximum tip velocity and 100 m/s maximum tip velocity are created to quantify these effects. Component costs, annualized energy production, and cost of energy are computed for each design to quantify the change in overall cost of energy resulting from the increase in turbine tip velocity. High fidelity physics based models rather than cost and scaling models are used to perform the work. Results provide a quantitative assessment of anticipated costs and benefits for high speed rotors. Finally, important lessons regarding full system optimization of wind turbines are documented.

  6. Optic-microwave mixing velocimeter for superhigh velocity measurement

    SciTech Connect (OSTI)

    Weng Jidong; Wang Xiang; Tao Tianjiong; Liu Cangli; Tan Hua [Laboratory for Shock Waves and Detonation Physics Research, Institute of Fluid Physics, P.O. Box 919-102, Mianyang, Sichuan 621900 (China)

    2011-12-15T23:59:59.000Z

    The phenomenon that a light beam reflected off a moving object experiences a Doppler shift in its frequency underlies practical interferometric techniques for remote velocity measurements, such as velocity interferometer system for any reflector (VISAR), displacement interferometer system for any reflector (DISAR), and photonic Doppler velocimetry (PDV). While VISAR velocimeters are often bewildered by the fringe loss upon high-acceleration dynamic process diagnosis, the optic-fiber velocimeters such as DISAR and PDV, on the other hand, are puzzled by high velocity measurement over 10 km/s, due to the demand for the high bandwidth digitizer. Here, we describe a new optic-microwave mixing velocimeter (OMV) for super-high velocity measurements. By using currently available commercial microwave products, we have constructed a simple, compact, and reliable OMV device, and have successfully obtained, with a digitizer of bandwidth 6 GH only, the precise velocity history of an aluminum flyer plate being accelerated up to 11.2 km/s in a three stage gas-gun experiment.

  7. Ducted kinetic Alfven waves in plasma with steep density gradients

    SciTech Connect (OSTI)

    Houshmandyar, Saeid [Solar Observatory Department, Prairie View A and M University, Prairie View, Texas 77446 (United States); Department of Physics, West Virginia University, Morgantown, West Virginia 26506-6315 (United States); Scime, Earl E. [Department of Physics, West Virginia University, Morgantown, West Virginia 26506-6315 (United States)

    2011-11-15T23:59:59.000Z

    Given their high plasma density (n {approx} 10{sup 13} cm{sup -3}), it is theoretically possible to excite Alfven waves in a conventional, moderate length (L {approx} 2 m) helicon plasma source. However, helicon plasmas are decidedly inhomogeneous, having a steep radial density gradient, and typically have a significant background neutral pressure. The inhomogeneity introduces regions of kinetic and inertial Alfven wave propagation. Ion-neutral and electron-neutral collisions alter the Alfven wave dispersion characteristics. Here, we present the measurements of propagating kinetic Alfven waves in helium helicon plasma. The measured wave dispersion is well fit with a kinetic model that includes the effects of ion-neutral damping and that assumes the high density plasma core defines the radial extent of the wave propagation region. The measured wave amplitude versus plasma radius is consistent with the pile up of wave magnetic energy at the boundary between the kinetic and inertial regime regions.

  8. Newberry EGS Seismic Velocity Model

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Templeton, Dennise

    We use ambient noise correlation (ANC) to create a detailed image of the subsurface seismic velocity at the Newberry EGS site down to 5 km. We collected continuous data for the 22 stations in the Newberry network, together with 12 additional stations from the nearby CC, UO and UW networks. The data were instrument corrected, whitened and converted to single bit traces before cross correlation according to the methodology in Benson (2007). There are 231 unique paths connecting the 22 stations of the Newberry network. The additional networks extended that to 402 unique paths crossing beneath the Newberry site.

  9. Newberry EGS Seismic Velocity Model

    SciTech Connect (OSTI)

    Templeton, Dennise

    2013-10-01T23:59:59.000Z

    We use ambient noise correlation (ANC) to create a detailed image of the subsurface seismic velocity at the Newberry EGS site down to 5 km. We collected continuous data for the 22 stations in the Newberry network, together with 12 additional stations from the nearby CC, UO and UW networks. The data were instrument corrected, whitened and converted to single bit traces before cross correlation according to the methodology in Benson (2007). There are 231 unique paths connecting the 22 stations of the Newberry network. The additional networks extended that to 402 unique paths crossing beneath the Newberry site.

  10. MEMS BASED DOPPLER VELOCITY MEASUREMENT SYSTEM

    E-Print Network [OSTI]

    White, Robert D.

    .2 Doppler Effect...................................................................................10 2MEMS BASED DOPPLER VELOCITY MEASUREMENT SYSTEM A dissertation submitted by Minchul Shin IN PARTIAL micromachined ultrasonic transducer (cMUT) based in-air Doppler velocity measurement system using a 1 cm2 planar

  11. Energy Savings and Peak Demand Reduction of a SEER 21 Heat Pump vs. a SEER 13 Heat Pump with Attic and Indoor Duct Systems

    SciTech Connect (OSTI)

    Cummings, J.; Withers, C.

    2014-03-01T23:59:59.000Z

    This report describes results of experiments that were conducted in an unoccupied 1600 square foot house--the Manufactured Housing (MH Lab) at the Florida Solar Energy Center (FSEC)--to evaluate the delivered performance as well as the relative performance of a SEER 21 variable capacity heat pump versus a SEER 13 heat pump. The performance was evaluated with two different duct systems: a standard attic duct system and an indoor duct system located in a dropped-ceiling space.

  12. Noise pair velocity and range echo location system

    DOE Patents [OSTI]

    Erskine, D.J.

    1999-02-16T23:59:59.000Z

    An echo-location method for microwaves, sound and light capable of using incoherent and arbitrary waveforms of wide bandwidth to measure velocity and range (and target size) simultaneously to high resolution is disclosed. Two interferometers having very long and nearly equal delays are used in series with the target interposed. The delays can be longer than the target range of interest. The first interferometer imprints a partial coherence on an initially incoherent source which allows autocorrelation to be performed on the reflected signal to determine velocity. A coherent cross-correlation subsequent to the second interferometer with the source determines a velocity discriminated range. Dithering the second interferometer identifies portions of the cross-correlation belonging to a target apart from clutter moving at a different velocity. The velocity discrimination is insensitive to all slowly varying distortions in the signal path. Speckle in the image of target and antenna lobing due to parasitic reflections is minimal for an incoherent source. An arbitrary source which varies its spectrum dramatically and randomly from pulse to pulse creates a radar elusive to jamming. Monochromatic sources which jigger in frequency from pulse to pulse or combinations of monochromatic sources can simulate some benefits of incoherent broadband sources. Clutter which has a symmetrical velocity spectrum will self-cancel for short wavelengths, such as the apparent motion of ground surrounding target from a sidelooking airborne antenna. 46 figs.

  13. Noise pair velocity and range echo location system

    DOE Patents [OSTI]

    Erskine, David J. (Oakland, CA)

    1999-01-01T23:59:59.000Z

    An echo-location method for microwaves, sound and light capable of using incoherent and arbitrary waveforms of wide bandwidth to measure velocity and range (and target size) simultaneously to high resolution. Two interferometers having very long and nearly equal delays are used in series with the target interposed. The delays can be longer than the target range of interest. The first interferometer imprints a partial coherence on an initially incoherent source which allows autocorrelation to be performed on the reflected signal to determine velocity. A coherent cross-correlation subsequent to the second interferometer with the source determines a velocity discriminated range. Dithering the second interferometer identifies portions of the cross-correlation belonging to a target apart from clutter moving at a different velocity. The velocity discrimination is insensitive to all slowly varying distortions in the signal path. Speckle in the image of target and antenna lobing due to parasitic reflections is minimal for an incoherent source. An arbitrary source which varies its spectrum dramatically and randomly from pulse to pulse creates a radar elusive to jamming. Monochromatic sources which jigger in frequency from pulse to pulse or combinations of monochromatic sources can simulate some benefits of incoherent broadband sources. Clutter which has a symmetrical velocity spectrum will self-cancel for short wavelengths, such as the apparent motion of ground surrounding target from a sidelooking airborne antenna.

  14. Radial Velocity Variability of Field Brown Dwarfs

    E-Print Network [OSTI]

    Prato, L; Rice, E L; McLean, I S; Kirkpatrick, J D; Burgasser, A J; Kim, S S

    2015-01-01T23:59:59.000Z

    We present paper six of the NIRSPEC Brown Dwarf Spectroscopic Survey, an analysis of multi-epoch, high-resolution (R~20,000) spectra of 25 field dwarf systems (3 late-type M dwarfs, 16 L dwarfs, and 6 T dwarfs) taken with the NIRSPEC infrared spectrograph at the W. M. Keck Observatory. With a radial velocity precision of ~2 km/s, we are sensitive to brown dwarf companions in orbits with periods of a few years or less given a mass ratio of 0.5 or greater. We do not detect any spectroscopic binary brown dwarfs in the sample. Given our target properties, and the frequency and cadence of observations, we use a Monte Carlo simulation to determine the detection probability of our sample. Even with a null detection result, our 1 sigma upper limit for very low mass binary frequency is 18%. Our targets included 7 known, wide brown dwarf binary systems. No significant radial velocity variability was measured in our multi-epoch observations of these systems, even for those pairs for which our data spanned a significant ...

  15. Energy Efficiency & Environmental News: Duct Cleaning and Indoor Air Quality 1 Florida Energy Extension Service and Gary Cook 2 DUCT CLEANING AND INDOOR AIR QUALITY

    E-Print Network [OSTI]

    unknown authors

    1994-01-01T23:59:59.000Z

    With concern about secondary smoke, dust mites, formaldehyde emissions and bioaerosols, the public has become more aware of indoor air quality problems. Heating, air conditioning and ventilation units as well as associated ductwork can be the sources of mold, fungi and other microbial pollutants as well as particulates of dust, secondary smoke and pieces of dead dust mites. Along with the public’s concern has been the development of businesses directly associated with indoor air quality. Some of these businesses are reputable and supply effective indoor air quality services; others, on the other hand, offer little more than technical jargon and will take advantage of the unwary consumer. Duct cleaning has been an area that has been attracted by both reputable and unscrupulous businesses.

  16. Design and Evaluation of a High Temperature Burner Duct Recuperator System

    E-Print Network [OSTI]

    Parks, W. P.; DeBellis, C. L.; Kneidel, K.

    savings of 41% for an unrecuperated furnace. A simple payback analysis indicated acceptable payback for installation in unrecuperated furnaces but unacceptable payback for recuperated furnaces at today's low gas prices."...

  17. Transit Detection of Radial Velocity Planets

    E-Print Network [OSTI]

    Stephen R. Kane; Kaspar von Braun

    2008-06-30T23:59:59.000Z

    The orbital parameters of extra-solar planets have a significant impact on the probability that the planet will transit the host star. This was recently demonstrated by the transit detection of HD 17156b whose favourable eccentricity and argument of periastron dramatically increased its transit likelihood. We present a study which provides a quantitative analysis of how these two orbital parameters effect the geometric transit probability as a function of period. Further, we apply these results to known radial velocity planets and show that there are unexpectedly high transit probabilities for planets at relatively long periods. For a photometric monitoring campaign which aims to determine if the planet indeed transits, we calculate the significance of a null result and the subsequent constraints that may be applied to orbital parameters.

  18. Tangential velocity measurement using interferometric MTI radar

    DOE Patents [OSTI]

    Doerry, Armin W.; Mileshosky, Brian P.; Bickel, Douglas L.

    2006-01-03T23:59:59.000Z

    Radar systems use time delay measurements between a transmitted signal and its echo to calculate range to a target. Ranges that change with time cause a Doppler offset in phase and frequency of the echo. Consequently, the closing velocity between target and radar can be measured by measuring the Doppler offset of the echo. The closing velocity is also known as radial velocity, or line-of-sight velocity. Doppler frequency is measured in a pulse-Doppler radar as a linear phase shift over a set of radar pulses during some Coherent Processing Interval (CPI). An Interferometric Moving Target Indicator (MTI) radar can be used to measure the tangential velocity component of a moving target. Multiple baselines, along with the conventional radial velocity measurement, allow estimating the true 3-D velocity of a target.

  19. Constraints on Neutrino Velocities Revisited

    E-Print Network [OSTI]

    Yunjie Huo; Tianjun Li; Yi Liao; Dimitri V. Nanopoulos; Yonghui Qi

    2012-01-27T23:59:59.000Z

    With a minimally modified dispersion relation for neutrinos, we reconsider the constraints on superluminal neutrino velocities from bremsstrahlung effects in the laboratory frame. Employing both the direct calculation approach and the virtual Z-boson approach, we obtain the generic decay width and energy loss rate of a superluminal neutrino with general energy. The Cohen-Glashow's analytical results for neutrinos with a relatively low energy are confirmed in both approaches. We employ the survival probability instead of the terminal energy to assess whether a neutrino with a given energy is observable or not in the OPERA experiment. Moreover, using our general results we perform systematical analyses on the constraints arising from the Super-Kamiokande and IceCube experiments.

  20. Seismic Velocity Estimation from Time Migration Velocities M. K. Cameron, S. B. Fomel, J. A. Sethian

    E-Print Network [OSTI]

    Sethian, James A.

    Seismic Velocity Estimation from Time Migration Velocities M. K. Cameron, S. B. Fomel, J. A the problem of estimating seismic velocities inside the earth which is necessary for obtaining seismic images in regular Cartesian coordinates. We derive a relation between the true seismic velocities and the routinely

  1. Building America Case Study: Raised Ceiling Interior Duct System, New Smyrna, Florida (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2014-09-01T23:59:59.000Z

    One of BA-PIRC's longtime Habitat for Humanity partners, S.E. Volusia CO (SEVHFH), was interested in building a home to the new Challenge Home standards. SEVHFH routinely builds ENERGY STAR V3.1 homes. The only modification to their design needed to comply with the Challenge Home criteria was the interior duct requirement. Unwilling to incur the added costs of a foam roof deck or wall heights above 8 feet to accommodate a fur-down chase SEVHFH opted to build a fur-up or raised ceiling chase.

  2. Impact of Phase Transitions on P Wave Velocities

    SciTech Connect (OSTI)

    D Weidner; L Li

    2011-12-31T23:59:59.000Z

    In regions where a high pressure phase is in equilibrium with a low pressure phase, the bulk modulus defined by the P-V relationship is greatly reduced. Here we evaluate the effect of such transitions on the P wave velocity. A model, where cation diffusion is the rate limiting factor, is used to project laboratory data to the conditions of a seismic wave propagating in the two-phase region. We demonstrate that for the minimum expected effect there is a significant reduction of the seismic velocity, as large as 10% over a narrow depth range.

  3. Wave VelocityWave Velocity Diff t f ti l l itDifferent from particle velocity

    E-Print Network [OSTI]

    Yoo, S. J. Ben

    Wave VelocityWave Velocity v=/T =f Diff t f ti l l itDifferent from particle velocity Depends on the medium in which the wave travelsDepends on the medium in which the wave travels stringaonvelocity F v of Waves11-8. Types of Waves Transverse wave Longitudinal wave Liu UCD Phy1B 2014 37 #12;Sound Wave

  4. An Experimental Method for Determining the Time Constants of Capacitive Thin-Film Polymer Humidity sensors at Various Duct Air Velocities 

    E-Print Network [OSTI]

    Dooley, B.; O'Neal, D.

    2008-01-01T23:59:59.000Z

    identical to the Candidate X test sensor. All sensors were brand new at the onset of this study, and each was shipped with a factory calibration certificate. The pertinent specifications reported by the manufacturer of each sensor are shown in Table I... of the Candidate Y sensor under Test 19 conditions was 'sensor was reported to be approximately 20 s (Table I) by the manufacturer. DATA REDUCTION AND ANALYSIS For a given test run, the RH...

  5. Nuclear reactor fuel assembly duct-tube-to-handling-socket attachment system

    DOE Patents [OSTI]

    Christiansen, David W. (Kennewick, WA); Smith, Bob G. (Kennewick, WA)

    1982-01-01T23:59:59.000Z

    A reusable system for removably attaching the upper end 10of a nuclear reactor duct tube to the lower end 30 of a nuclear reactor fuel assembly handling socket. A transition ring 20, fixed to the duct tube's upper end 10, has an interior-threaded section 22 with a first locking hole segment 24. An adaptor ring 40, fixed to the handling socket's lower end 30 has an outside-threaded section 42 with a second locking hole segment 44. The inside 22 and outside 42 threaded sections match and can be joined so that the first 24 and second 44 locking hole segments can be aligned to form a locking hole. A locking ring 50, with a locking pin 52, slides over the adaptor ring 40 so that the locking pin 52 fits in the locking hole. A swage lock 60 or a cantilever finger lock 70 is formed from the locking cup collar 26 to fit in a matching groove 54 or 56 in the locking ring 50 to prevent the locking ring's locking pin 52 from backing out of the locking hole.

  6. Scaleup tests and supporting research for the development of duct injection technology

    SciTech Connect (OSTI)

    Felix, L.G.; Dismukes, E.B.; Gooch, J.P. (Southern Research Inst., Birmingham, AL (United States)); Klett, M.G.; Demian, A.G. (Gilbert/Commonwealth, Inc., Reading, PA (United States))

    1992-04-20T23:59:59.000Z

    This Topical Report No. 2 is an interim report on the Duct Injection Test Facility being operated for the Department of Energy at Beverly, Ohio. Either dry calcium hydroxide or an aqueous slurry of calcium hydroxide (prepared by slaking quicklime) is injected into a slipstream of flue gas to achieve partial removal of SO{sub 2} from a coal-burning power station. Water injected with the slurry or injected separately from the dry sorbents cools the flue gas and increases the water vapor content of the gas. The addition of water, either in the slurry or in a separate spray, makes the extent of reaction between the sorbent and the SO{sub 2} more complete; the presumption is that water is effective in the liquid state, when it is able to wet the sorbent particles physically, and not especially effective in the vapor state. An electrostatic precipitator collects the combination of suspended solids (fly ash from the boiler and sorbent from the duct injection process). All of the operations are being carried out on the scale of approximately 50,000 acfm of flue gas.

  7. Scaleup tests and supporting research for the development of duct injection technology. Topical report No. 1, Literature review

    SciTech Connect (OSTI)

    Gooch, J.P.; Dismukes, E.B.; Dahlin, R.S.; Faulkner, M.G. [Southern Research Inst., Birmingham, AL (United States); Klett, M.G.; Buchanan, T.L.; Hunt, J.E. [Gilbert/Commonwealth, Inc., Reading, PA (United States)

    1989-05-01T23:59:59.000Z

    Gilbert Commonwealth, Southern Research Institute and the American Electric Power Service Corporation have embarked on a program to convert DOE`s Duct Injection Test Facility located at the Muskingum River Power Plant of Ohio Power Company to test alternate duct injection technologies. The technologies to be tested include slurry sorbent injection of hydrated lime using dual fluid nozzles, or a rotary atomizer and pneumatic injection of hydrated lime, with flue gas humidification before or after sorbent injection. The literature review and analysis contained in this report is a part of the preparatory effort for the test program.

  8. Duct Leakage Modeling in EnergyPlus and Analysis of Energy Savings from Implementing SAV with InCITeTM

    SciTech Connect (OSTI)

    Wray, Craig; Sherman, Max

    2010-03-01T23:59:59.000Z

    This project addressed two significant deficiencies in air-handling systems for large commercial building: duct leakage and duct static pressure reset. Both constitute significant energy reduction opportunities for these buildings. The overall project goal is to bridge the gaps in current duct performance modeling capabilities, and to expand our understanding of air-handling system performance in California large commercial buildings. The purpose of this project is to provide technical support for the implementation of a duct leakage modeling capability in EnergyPlus, to demonstrate the capabilities of the new model, and to carry out analyses of field measurements intended to demonstrate the energy saving potential of the SAV with InCITeTM duct static pressure reset (SPR) technology. A new duct leakage model has been successfully implemented in EnergyPlus, which will enable simulation users to assess the impacts of leakage on whole-building energy use and operation in a coupled manner. This feature also provides a foundation to support code change proposals and compliance analyses related to Title 24 where duct leakage is an issue. Our example simulations continue to show that leaky ducts substantially increase fan power: 10percent upstream and 10percent downstream leakage increases supply fan power 30percent on average compared to a tight duct system (2.5percent upstream and 2.5percent downstream leakage). Much of this increase is related to the upstream leakage rather than to the downstream leakage. This does not mean, however, that downstream leakage is unimportant. Our simulations also demonstrate that ceiling heat transfer is a significant effect that needs to be included when assessing the impacts of duct leakage in large commercial buildings. This is not particularly surprising, given that ?ceiling regain? issues have already been included in residential analyses as long as a decade ago (e.g., ASHRAE Standard 152); mainstream simulation programs that are used for large commercial building energy analyses have not had this capability until now. Our analyses of data that we collected during our 2005 tests of the SAV with InCITeTM duct static pressure reset technology show that this technology can substantially reduce fan power (in this case, by about 25 to 30percent). Tempering this assessment, however, is that cooling and heating coil loads were observed to increase or decrease significantly depending on the time window used. Their impact on cooling and heating plant power needs to be addressed in future studies; without translating the coil loads to plant equipment energy use, it is not possible to judge the net impact of this SPR technology on whole-building energy use. If all of the loads had decreased, such a step would not be as necessary.

  9. Instructions for use Short-term Glacier Velocity Changes at West Kunlun

    E-Print Network [OSTI]

    Tsunogai, Urumu

    to global warming could further accelerate glacier15 flow and potentially lead to significant lossInstructions for use #12;Short-term Glacier Velocity Changes at West Kunlun Shan, Northwest Tibet. Abstract Seasonal glacier velocity changes across the High Arctic, including the Green- land Ice Sheet

  10. Precision reconstruction of the dark matter-neutrino relative velocity from N-body simulations

    E-Print Network [OSTI]

    Inman, Derek; Pen, Ue-Li; Farchi, Alban; Yu, Hao-Ran; Harnois-Deraps, Joachim

    2015-01-01T23:59:59.000Z

    Discovering the mass of neutrinos is a principle goal in high energy physics and cosmology. In addition to cosmological measurements based on two-point statistics, the neutrino mass can also be estimated by observations of neutrino wakes resulting from the relative motion between dark matter and neutrinos. Such a detection relies on an accurate reconstruction of the dark matter-neutrino relative velocity which is affected by non-linear structure growth and galaxy bias. We investigate our ability to reconstruct this relative velocity using large N-body simulations where we evolve neutrinos as distinct particles alongside the dark matter. We find that the dark matter velocity power spectrum is overpredicted by linear theory whereas the neutrino velocity power spectrum is underpredicted. The magnitude of the relative velocity observed in the simulations is found to be lower than what is predicted in linear theory. Since neither the dark matter nor the neutrino velocity fields are directly observable from galaxy ...

  11. Chapter 6 x Viscous Flow in Ducts 437 6.5 In flow past a body or wall, early

    E-Print Network [OSTI]

    Bahrami, Majid

    . Estimate the minimum filling time if the tube flow is to remain laminar. For what cola (water) temperature) horizontal; and (b) vertical with the flow up? Solution: Equation (6.9b) applies in both cases, notingChapter 6 x Viscous Flow in Ducts 437 6.5 In flow past a body or wall, early transition

  12. IEEE TRANSACTIONS ON COMMUNICATIONS, VOL. 53, NO. 2, FEBRUARY 2005 335 On the Capacity Limits of HVAC Duct Channel for

    E-Print Network [OSTI]

    Stancil, Daniel D.

    and experimental channel-capacity estimates of heating, ventilation, and air condi- tioning (HVAC) ducts based in indoor wireless networks. Index Terms--Heating, ventilation, and air conditioning (HVAC) systems building is already equipped with a microwave distribution system: the heating, ventilation, and air

  13. Procedure and Application for Determining the Cold Deck and Hot Deck Airflow in a Dual-Duct System

    E-Print Network [OSTI]

    Liu, G.; Mingsheng, L.

    2006-01-01T23:59:59.000Z

    This paper introduces an innovative method to determine the cold and hot airflow through a dual-duct variable air volume (VAV) system. The actual building load can be identified based on the calculated airflow and temperature for both the cold...

  14. Minimum and terminal velocities in projectile motion

    E-Print Network [OSTI]

    E. N. Miranda; S. Nikolskaya; R. Riba

    2012-08-13T23:59:59.000Z

    The motion of a projectile with horizontal initial velocity V0, moving under the action of the gravitational field and a drag force is studied analytically. As it is well known, the projectile reaches a terminal velocity Vterm. There is a curious result concerning the minimum speed Vmin; it turns out that the minimum velocity is lower than the terminal one if V0 > Vterm and is lower than the initial one if V0 < Vterm. These results show that the velocity is not a monotonous function. If the initial speed is not horizontal, there is an angle range where the velocity shows the same behavior mentioned previously. Out of that range, the volocity is a monotonous function. These results come out from numerical simulations.

  15. Slow Sound in a duct, effective transonic flows and analogue black holes

    E-Print Network [OSTI]

    Yves Aurégan; Pierre Fromholz; Florent Michel; Vincent Pagneux; Renaud Parentani

    2015-03-09T23:59:59.000Z

    We propose a new system suitable for studying analogue gravity effects, consisting of a gas flowing in a duct with a compliant wall. Effective transonic flows are obtained from uniform, low Mach number flows through the reduction of the one-dimensional speed of sound induced by the wall compliance. We show that the modified equation for linear perturbations can be written in a Hamiltonian form. We perform a one-dimensional reduction consistent with the canonical formulation, and deduce the analogue metric along with the first dispersive term. In a weak dispersive regime, the spectrum emitted from a sonic horizon is numerically shown to be Planckian, and with a temperature fixed by the analogue surface gravity.

  16. Slow Sound in a duct, effective transonic flows and analogue black holes

    E-Print Network [OSTI]

    Aurégan, Yves; Michel, Florent; Pagneux, Vincent; Parentani, Renaud

    2015-01-01T23:59:59.000Z

    We propose a new system suitable for studying analogue gravity effects, consisting of a gas flowing in a duct with a compliant wall. Effective transonic flows are obtained from uniform, low Mach number flows through the reduction of the one-dimensional speed of sound induced by the wall compliance. We show that the modified equation for linear perturbations can be written in a Hamiltonian form. We perform a one-dimensional reduction consistent with the canonical formulation, and deduce the analogue metric along with the first dispersive term. In a weak dispersive regime, the spectrum emitted from a sonic horizon is numerically shown to be Planckian, and with a temperature fixed by the analogue surface gravity.

  17. Can pancreatic duct-derived progenitors be a source of islet regeneration?

    SciTech Connect (OSTI)

    Xia, Bing [Department of Endocrinology, First Hospital of Harbin Medical University, Harbin, Hei Long Jiang Province 150001 (China)] [Department of Endocrinology, First Hospital of Harbin Medical University, Harbin, Hei Long Jiang Province 150001 (China); Zhan, Xiao-Rong, E-mail: xiaorongzhan@sina.com [Department of Endocrinology, First Hospital of Harbin Medical University, Harbin, Hei Long Jiang Province 150001 (China)] [Department of Endocrinology, First Hospital of Harbin Medical University, Harbin, Hei Long Jiang Province 150001 (China); Yi, Ran [Department of Endocrinology, First Hospital of Harbin Medical University, Harbin, Hei Long Jiang Province 150001 (China)] [Department of Endocrinology, First Hospital of Harbin Medical University, Harbin, Hei Long Jiang Province 150001 (China); Yang, Baofeng [Department of Pharmacology, State Key Laboratory of Biomedicine and Pharmacology, Harbin Medical University, Harbin, Hei Long Jiang Province 150001 (China)] [Department of Pharmacology, State Key Laboratory of Biomedicine and Pharmacology, Harbin Medical University, Harbin, Hei Long Jiang Province 150001 (China)

    2009-06-12T23:59:59.000Z

    The regenerative process of the pancreas is of interest because the main pathogenesis of diabetes mellitus is an inadequate number of insulin-producing {beta}-cells. The functional mass of {beta}-cells is decreased in type 1 diabetes, so replacing missing {beta}-cells or triggering their regeneration may allow for improved type 1 diabetes treatment. Therefore, expansion of the {beta}-cell mass from endogenous sources, either in vivo or in vitro, represents an area of increasing interest. The mechanism of islet regeneration remains poorly understood, but the identification of islet progenitor sources is critical for understanding {beta}-cell regeneration. One potential source is the islet proper, via the dedifferentiation, proliferation, and redifferentiation of facultative progenitors residing within the islet. Neogenesis, or that the new pancreatic islets can derive from progenitor cells present within the ducts has been reported, but the existence and identity of the progenitor cells have been debated. In this review, we focus on pancreatic ductal cells, which are islet progenitors capable of differentiating into islet {beta}-cells. Islet neogenesis, seen as budding of hormone-positive cells from the ductal epithelium, is considered to be one mechanism for normal islet growth after birth and in regeneration, and has suggested the presence of pancreatic stem cells. Numerous results support the neogenesis hypothesis, the evidence for the hypothesis in the adult comes primarily from morphological studies that have in common the production of damage to all or part of the pancreas, with consequent inflammation and repair. Although numerous studies support a ductal origin for new islets after birth, lineage-tracing experiments are considered the 'gold standard' of proof. Lineage-tracing experiments show that pancreatic duct cells act as progenitors, giving rise to new islets after birth and after injury. The identification of differentiated pancreatic ductal cells as an in vivo progenitor for pancreatic {beta}-cells has implications for a potentially important, expandable source of new islets for diabetic replenishment therapy.

  18. Impact of Ducting on Heat Pump Water Heater Space Conditioning Energy Use and Comfort

    SciTech Connect (OSTI)

    Widder, Sarah H.; Petersen, Joseph M.; Parker, Graham B.; Baechler, Michael C.

    2014-07-21T23:59:59.000Z

    Increasing penetration of heat pump water heaters (HPWHs) in the residential sector will offer an important opportunity for energy savings, with a theoretical energy savings of up to 63% per water heater and up to 11% of residential energy use (EIA 2009). However, significant barriers must be overcome before this technology will reach widespread adoption in the Pacific Northwest region and nationwide. One significant barrier noted by the Northwest Energy Efficiency Alliance (NEEA) is the possible interaction with the homes’ space conditioning system for units installed in conditioned spaces. Such complex interactions may decrease the magnitude of whole-house savings available from HPWH installed in the conditioned space in cold climates and could lead to comfort concerns (Larson et al. 2011; Kresta 2012). Modeling studies indicate that the installation location of HPWHs can significantly impact their performance and the resultant whole-house energy savings (Larson et al. 2012; Maguire et al. 2013). However, field data are not currently available to validate these results. This field evaluation of two GE GeoSpring HPWHs in the PNNL Lab Homes is designed to measure the performance and impact on the Lab Home HVAC system of a GE GeoSpring HPWH configured with exhaust ducting compared to an unducted GeoSpring HPWH during heating and cooling season periods; and measure the performance and impact on the Lab Home HVAC system of the GeoSpring HPWH with both supply and exhaust air ducting as compared to an unducted GeoSpring HPWH during heating and cooling season periods. Important metrics evaluated in these experiments include water heater energy use, HVAC energy use, whole house energy use, interior temperatures (as a proxy for thermal comfort), and cost impacts. This technical report presents results from the PNNL Lab Homes experiment.

  19. Cosmological Constraints from Galaxy Cluster Velocity Statistics

    E-Print Network [OSTI]

    Suman Bhattacharya; Arthur Kosowsky

    2007-04-20T23:59:59.000Z

    Future microwave sky surveys will have the sensitivity to detect the kinematic Sunyaev-Zeldovich signal from moving galaxy clusters, thus providing a direct measurement of their line-of-sight peculiar velocity. We show that cluster peculiar velocity statistics applied to foreseeable surveys will put significant constraints on fundamental cosmological parameters. We consider three statistical quantities that can be constructed from a cluster peculiar velocity catalog: the probability density function, the mean pairwise streaming velocity, and the pairwise velocity dispersion. These quantities are applied to an envisioned data set which measures line-of-sight cluster velocities with normal errors of 100 km/s for all clusters with masses larger than $10^{14}$ solar masses over a sky area of up to 5000 square degrees. A simple Fisher matrix analysis of this survey shows that the normalization of the matter power spectrum and the dark energy equation of state can be constrained to better than 10 percent, and the Hubble constant and the primordial power spectrum index can be constrained to a few percent, independent of any other cosmological observations. We also find that the current constraint on the power spectrum normalization can be improved by more than a factor of two using data from a 400 square degree survey and WMAP third-year priors. We also show how the constraints on cosmological parameters changes if cluster velocities are measured with normal errors of 300 km/s.

  20. Estimating seismic velocities at ultrasonic frequencies in partially saturated rocks

    SciTech Connect (OSTI)

    Mavko, G.; Nolen-Hoeksema, R. (Stanford Univ., CA (United States). Dept. of Geophysics)

    1994-02-01T23:59:59.000Z

    Seismic velocities in rocks at ultrasonic frequencies depend not only on the degree of saturation but also on the distribution of the fluid phase at various scales within the pore space. Two scales of saturation heterogeneity are important: (1) saturation differences between thin compliant pores and larger stiffer pores, and (2) differences between saturated patches and undersaturated patches at a scale much larger than any pore. The authors propose a formalism for predicting the range of velocities in partially saturated rocks that avoids assuming idealized pore shapes by using measured dry rock velocity versus pressure and dry rock porosity versus pressure. The pressure dependence contains all of the necessary information about the distribution of pore compliance for estimating effects of saturation at the finest scales where small amounts of fluid in the thinnest, most compliant parts of the pore space stiffen the rock in both compression and shear (increasing both P- and S-wave velocities) in approximately the same way that confining pressure stiffens the rock by closing the compliant pores. Large-scale saturation patches tend to increase only the high-frequency bulk modulus by amounts roughly proportional to the saturation. The pore-scale effects will be most important at laboratory and logging frequencies when pore-scale pore pressure gradients are unrelaxed. The patchy-saturation effects can persist even at seismic field frequencies if the patch sizes are sufficiently large and the diffusivities are sufficiently low for the larger-scale pressure gradients to be unrelaxed.

  1. Temporal Entropy Generation in the Viscous Layers of Laterally-converging Duct Flows

    SciTech Connect (OSTI)

    Donald M. McEligot; Robert S. Brodkey; Helmut Eckelmann

    2008-12-01T23:59:59.000Z

    Since insight into entropy generation is a key to increasing efficiency and thereby reducing fuel consumption and/or waste and -- for wall-bounded flows -- most entropy is generated in the viscous layer, we examine the transient behavior of its dominant contributor there for a non-canonical flow. New measurements in oil flow are presented for the effects of favorable streamwise mean pressure gradients on temporal entropy generation rates and, in the process, on key Reynolds-stress-producing events such as sweep front passage and on the deceleration/outflow phase of the overall bursting process. Two extremes have been considered: (1) a high pressure gradient, nearing "laminarization," and (2), for comparison, a low pressure gradient corresponding to many earlier experiments. In both cases, the peak temporal entropy generation rate occurs shortly after passage of the ejection/sweep interface. Whether sweep and ejection rates appear to decrease or increase with the pressure gradient depends on the feature examined and the manner of sampling. When compared using wall coordinates for velocities, distances and time, the trends and magnitudes of the transient behaviors are mostly the same. The main effects of the higher pressure gradient are (1) changes in the time lag between detections -- representing modification of the shape of the sweep front and the sweep angle with the wall, (2) modification of the magnitude of an instantaneous Reynolds shear stress with wall distance and (3) enlarging the sweeps and ejections. Results new for both low and high pressure gradients are the temporal behaviors of the dominant contribution to entropy generation; it is found to be much more sensitive to distance from the wall than to streamwise pressure gradient.

  2. The stellar wind velocity field of HD 77581

    E-Print Network [OSTI]

    Manousakis, A

    2015-01-01T23:59:59.000Z

    The early acceleration of stellar winds in massive stars is poorly constrained. The scattering of hard X-ray photons emitted by the pulsar in the high-mass X-ray binary Vela X-1 can be used to probe the stellar wind velocity and density profile close to the surface of its supergiant companion HD 77581. We built a high signal-to-noise and high resolution hard X-ray lightcurve of Vela X-1 measured by Swift/BAT over 300 orbital periods of the system and compared it with the predictions of a grid of hydrodynamic simulations. We obtain a very good agreement between observations and simulations for a narrow set of parameters, implying that the wind velocity close to the stellar surface is twice larger than usually assumed with the standard beta law. Locally a velocity gradient of $\\beta\\sim0.5$ is favoured. Even if still incomplete, hydrodynamic simulations are successfully reproducing several observational properties of Vela X-1.

  3. Measuring Stellar Radial Velocities with a Dispersed Fixed-Delay Interferometer

    E-Print Network [OSTI]

    Suvrath Mahadevan; Julian van Eyken; Jian Ge; Curtis DeWitt; Scott W. Fleming; Roger Cohen; Justin Crepp; Andrew Vanden Heuvel

    2008-01-25T23:59:59.000Z

    We demonstrate the ability to measure precise stellar barycentric radial velocities with the dispersed fixed-delay interferometer technique using the Exoplanet Tracker (ET), an instrument primarily designed for precision differential Doppler velocity measurements using this technique. Our barycentric radial velocities, derived from observations taken at the KPNO 2.1 meter telescope, differ from those of Nidever et al. by 0.047 km/s (rms) when simultaneous iodine calibration is used, and by 0.120 km/s (rms) without simultaneous iodine calibration. Our results effectively show that a Michelson interferometer coupled to a spectrograph allows precise measurements of barycentric radial velocities even at a modest spectral resolution of R ~ 5100. A multi-object version of the ET instrument capable of observing ~500 stars per night is being used at the Sloan 2.5 m telescope at Apache Point Observatory for the Multi-object APO Radial Velocity Exoplanet Large-area Survey (MARVELS), a wide-field radial velocity survey for extrasolar planets around TYCHO-2 stars in the magnitude range 7.6velocities, this survey will also yield precise barycentric radial velocities for many thousands of stars using the data analysis techniques reported here. Such a large kinematic survey at high velocity precision will be useful in identifying the signature of accretion events in the Milky Way and understanding local stellar kinematics in addition to discovering exoplanets, brown dwarfs and spectroscopic binaries.

  4. Undersampling to accelerate time-resolved MRI velocity measurement of carotid blood flow 

    E-Print Network [OSTI]

    Tao, Yuehui

    2009-01-01T23:59:59.000Z

    Time-resolved velocity information of carotid blood flow can be used to estimate haemodynamic conditions associated with carotid artery disease leading to stroke. MRI provides high-resolution measurement of such information ...

  5. Modeling velocity dispersion In Gypsy site, Oklahoma

    E-Print Network [OSTI]

    Alsaadan, Sami Ibrahim

    2010-01-01T23:59:59.000Z

    Discrepancies in interval velocities estimated from vertical well measurements made with different source central frequencies at Gypsy site could be primarily explained in terms of intrinsic attenuation. Four intervals ...

  6. Acoustic measurement of potato cannon velocity

    E-Print Network [OSTI]

    Courtney, M; Courtney, Amy; Courtney, Michael

    2006-01-01T23:59:59.000Z

    This article describes measurement of potato cannon velocity with a digitized microphone signal. A microphone is attached to the potato cannon muzzle and a potato is fired at an aluminum target about 10 m away. The potato's flight time can be determined from the acoustic waveform by subtracting the time in the barrel and time for sound to return from the target. The potato velocity is simply the flight distance divided by the flight time.

  7. FIELD EVALUATION OF IMPROVED METHODS FOR MEASURING THE AIR LEAKAGE OF DUCT SYSTEMS UNDER NORMAL OPERATING CONDITIONS IN 51 HOMES

    SciTech Connect (OSTI)

    Paul W. Francisco; Larry Palmiter; Erin Kruse; Bob Davis

    2003-10-18T23:59:59.000Z

    Duct leakage in forced-air distribution systems has been recognized for years as a major source of energy losses in residential buildings. Unfortunately, the distribution of leakage across homes is far from uniform, and measuring duct leakage under normal operating conditions has proven to be difficult. Recently, two new methods for estimating duct leakage at normal operating conditions have been devised. These are called the nulling test and the Delta-Q test. Small exploratory studies have been done to evaluate these tests, but previously no large-scale study on a broad variety of homes has been performed to determine the accuracy of these new methods in the field against an independent benchmark of leakage. This sort of study is important because it is difficult in a laboratory setting to replicate the range of leakage types found in real homes. This report presents the results of a study on 51 homes to evaluate these new methods relative to an independent benchmark and a method that is currently used. An evaluation of the benchmark procedure found that it worked very well for supply-side leakage measurements, but not as well on the return side. The nulling test was found to perform well, as long as wind effects were minimal. Unfortunately, the time and difficulty of setup can be prohibitive, and it is likely that this method will not be practical for general use by contractors except in homes with no return ducts. The Delta-Q test was found to have a bias resulting in overprediction of the leakage, which qualitatively confirms the results of previous laboratory, simulation, and small-scale field studies. On average the bias was only a few percent of the air handler flow, but in about 20% of the homes the bias was large. A primary flaw with the Delta-Q test is the assumption that the pressure between the ducts and the house remain constant during the test, as this assumption does not hold true. Various modifications to the Delta-Q method were evaluated as possible improvements. Only one of these modifications provided improved results. This modification requires measuring the duct pressure relative to the house at either every pressure station within the Delta-Q test or at the extremes of the house pressure range involved in the Delta-Q test. If the pressures are only measured at the extremes, then calculated pressures at the other pressure stations are obtained via interpolation. Using these pressures reduced the bias in the Delta-Q test by about one-third.

  8. Measuring Outdoor Air Intake Rates Using Electronic Velocity Sensors at Louvers and Downstream of Airflow Straighteners

    E-Print Network [OSTI]

    Fisk, William

    2008-01-01T23:59:59.000Z

    Sensors at Louvers and Downstream of Airflow StraightenersSensors at Louvers and Downstream of Airflow Straightenersprobes located in the duct downstream of the intake louver

  9. Extracting Fish and Water Velocity from Doppler Profiler Data

    E-Print Network [OSTI]

    deYoung, Brad

    Extracting Fish and Water Velocity from Doppler Profiler Data ĺ Ð 1 ¸ Ö Ò ×¹ Ò ÝÖ¹Ê Ò 2 1 processing algo- rithms normally used to extract water velocity. We present an alternative method for velocity homogeneity precludes the extraction of fish velocities. Water velocities can sometimes still

  10. Building America Technology Solutions for New and Existing Homes: New Insights for Improving the Designs of Flexible Duct Junction Boxes (Fact Sheet)

    Broader source: Energy.gov [DOE]

    IBACOS explored the relationships between pressure and physical configurations of flexible duct junction boxes by using computational fluid dynamics simulations to predict individual box parameters and total system pressure, thereby ensuring improved HVAC performance.

  11. Evaluation of mixing in three duct configurations and development of a Generic Tee Plenum System (GTPS) for application to single point aerosol sampling

    E-Print Network [OSTI]

    Han, Tae Won

    2003-01-01T23:59:59.000Z

    to characterize the degree of mixing at downstream locations as affected by several types of flow disturbances, including a plenum consisting with duct intakes, a rectangular elbow with turning vanes, 90? elbows, tees, commercial static mixing device and GTPS...

  12. Velocity dependence of friction of confined polymers

    E-Print Network [OSTI]

    I. M. Sivebaek; V. N. Samoilov; B. N. J. Persson

    2009-11-18T23:59:59.000Z

    We present molecular dynamics friction calculations for confined hydrocarbon solids with molecular lengths from 20 to 1400 carbon atoms. Two cases are considered: (a) polymer sliding against a hard substrate, and (b) polymer sliding on polymer. We discuss the velocity dependence of the frictional shear stress for both cases. In our simulations, the polymer films are very thin (approx. 3 nm), and the solid walls are connected to a thermostat at a short distance from the polymer slab. Under these circumstances we find that frictional heating effects are not important, and the effective temperature in the polymer film is always close to the thermostat temperature. In the first setup (a), for hydrocarbons with molecular lengths from 60 to 1400 carbon atoms, the shear stresses are nearly independent of molecular length, but for the shortest hydrocarbon C20H42 the frictional shear stress is lower. In all cases the frictional shear stress increases monotonically with the sliding velocity. For polymer sliding on polymer [case (b)] the friction is much larger, and the velocity dependence is more complex. For hydrocarbons with molecular lengths from 60 to 140 C-atoms, the number of monolayers of lubricant increases (abruptly) with increasing sliding velocity (from 6 to 7 layers), leading to a decrease of the friction. Before and after the layering transition, the frictional shear stresses are nearly proportional to the logarithm of sliding velocity. For the longest hydrocarbon (1400 C-atoms) the friction shows no dependence on the sliding velocity, and for the shortest hydrocarbon (20 C-atoms) the frictional shear stress increases nearly linearly with the sliding velocity.

  13. GALAXY CLUSTER BULK FLOWS AND COLLISION VELOCITIES IN QUMOND

    SciTech Connect (OSTI)

    Katz, Harley; McGaugh, Stacy; Teuben, Peter [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Angus, G. W., E-mail: hkatz@astro.umd.edu, E-mail: stacy.mcgaugh@case.edu, E-mail: teuben@astro.umd.edu, E-mail: angus.gz@gmail.com [Astrophysics, Cosmology and Gravity Centre, University of Cape Town, Private Bag X3, Rondebosch 7700 (South Africa)

    2013-07-20T23:59:59.000Z

    We examine the formation of clusters of galaxies in numerical simulations of a QUMOND cosmogony with massive sterile neutrinos. Clusters formed in these exploratory simulations develop higher velocities than those found in {Lambda}CDM simulations. The bulk motions of clusters attain {approx}1000 km s{sup -1} by low redshift, comparable to observations whereas {Lambda}CDM simulated clusters tend to fall short. Similarly, high pairwise velocities are common in cluster-cluster collisions like the Bullet Cluster. There is also a propensity for the most massive clusters to be larger in QUMOND and to appear earlier than in {Lambda}CDM, potentially providing an explanation for ''pink elephants'' like El Gordo. However, it is not obvious that the cluster mass function can be recovered.

  14. Relation between plasma plume density and gas flow velocity in atmospheric pressure plasma

    SciTech Connect (OSTI)

    Yambe, Kiyoyuki; Taka, Shogo; Ogura, Kazuo [Graduate School of Science and Technology, Niigata University, Niigata 950-2181 (Japan)] [Graduate School of Science and Technology, Niigata University, Niigata 950-2181 (Japan)

    2014-04-15T23:59:59.000Z

    We have studied atmospheric pressure plasma generated using a quartz tube, helium gas, and copper foil electrode by applying RF high voltage. The atmospheric pressure plasma in the form of a bullet is released as a plume into the atmosphere. To study the properties of the plasma plume, the plasma plume current is estimated from the difference in currents on the circuit, and the drift velocity is measured using a photodetector. The relation of the plasma plume density n{sub plu}, which is estimated from the current and the drift velocity, and the gas flow velocity v{sub gas} is examined. It is found that the dependence of the density on the gas flow velocity has relations of n{sub plu} ? log(v{sub gas}). However, the plasma plume density in the laminar flow is higher than that in the turbulent flow. Consequently, in the laminar flow, the density increases with increasing the gas flow velocity.

  15. Experimental High Velocity Acid Jetting in Limestone Carbonates

    E-Print Network [OSTI]

    Holland, Christopher

    2014-04-30T23:59:59.000Z

    spacers have an OD of 4” and an ID of 3.5”. One spacer ring has a 2” length and the other has a 0.25” length for a total Lsp of 2.25”. Therefore, from Eq. 2.13: (2.14) The outlet holder, Fig. 2.4D secures the outlet side...…………………………………………………………… 2.2 Pulse Pump……………………………………………………………… 2.3 Core Holder…………………………………………………………….. 2.4 Hydraulic Pump………………………………………………………… 2.5 Backpressure Regulator…………………………………………………. 2.6 Data Acquisition………………………………………………………… 2.7 Permeability Measuring...

  16. Particle deposition from turbulent flow: Review of published research and its applicability to ventilation ducts in commercial buildings

    SciTech Connect (OSTI)

    Sippola, Mark R.; Nazaroff, William W.

    2002-06-01T23:59:59.000Z

    This report reviews published experimental and theoretical investigations of particle deposition from turbulent flows and considers the applicability of this body of work to the specific case of particle deposition from flows in the ducts of heating, ventilating and air conditioning (HVAC) systems. Particle deposition can detrimentally affect the performance of HVAC systems and it influences the exposure of building occupants to a variety of air pollutants. The first section of this report describes the types of HVAC systems under consideration and discusses the components, materials and operating parameters commonly found in these systems. The second section reviews published experimental investigations of particle deposition rates from turbulent flows and considers the ramifications of the experimental evidence with respect to HVAC ducts. The third section considers the structure of turbulent airflows in ventilation ducts with a particular emphasis on turbulence investigations that have been used as a basis for particle deposition models. The final section reviews published literature on predicting particle deposition rates from turbulent flows.

  17. air velocity effects: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    transfer velocities. A moving tropical cyclone is an intense source of surface wind stress Chu, Peter C. 4 The exit velocity of a compressed air cannon CERN Preprints...

  18. On the definition of velocity in doubly special relativity theories

    E-Print Network [OSTI]

    Piotr Kosinski; Pawel Maslanka

    2002-11-13T23:59:59.000Z

    We discuss the definition of particle velocity in doubly relativity theories. The general formula relating velocity and four-momentum of particle is given.

  19. Antarctica: measuring glacier velocity from satellite images

    SciTech Connect (OSTI)

    Lucchitta, B.K.; Ferguson, H.M.

    1986-11-28T23:59:59.000Z

    Many Landsat images of Antarctica show distinctive flow and crevasse features in the floating part of ice streams and outlet glaciers immediately below their grounding zones. Some of the features, which move with the glacier or ice stream, remain visible over many years and thus allow time-lapse measurements of ice velocities. Measurements taken from Landsat images of features on Byrd Glacier agree well with detailed ground and aerial observations. The satellite-image technique thus offers a rapid and cost-effective method of obtaining average velocities, to a first order of accuracy, of many ice streams and outlet glaciers near their termini.

  20. Lagrangian reconstruction of cosmic velocity fields

    E-Print Network [OSTI]

    G. Lavaux

    2008-01-28T23:59:59.000Z

    We discuss a Lagrangian reconstruction method of the velocity field from galaxy redshift catalog that takes its root in the Euler equation. This results in a ``functional'' of the velocity field which must be minimized. This is helped by an algorithm solving the minimization of cost-flow problems. The results obtained by applying this method to cosmological problems are shown and boundary effects happening in real observational cases are then discussed. Finally, a statistical model of the errors made by the reconstruction method is proposed.

  1. Threshold velocity for environmentally-assisted cracking in low alloy steels

    SciTech Connect (OSTI)

    Wire, G.L.; Kandra, J.T.

    1997-04-01T23:59:59.000Z

    Environmentally Assisted Cracking (EAC) in low alloy steels is generally believed to be activated by dissolution of MnS inclusions at the crack tip in high temperature LWR environments. EAC is the increase of fatigue crack growth rate of up to 40 to 100 times the rate in air that occurs in high temperature LWR environments. A steady state theory developed by Combrade, suggested that EAC will initiate only above a critical crack velocity and cease below this same velocity. A range of about twenty in critical crack tip velocities was invoked by Combrade, et al., to describe data available at that time. This range was attributed to exposure of additional sulfides above and below the crack plane. However, direct measurements of exposed sulfide densities on cracked specimens were performed herein and the results rule out significant additional sulfide exposure as a plausible explanation. Alternatively, it is proposed herein that localized EAC starting at large sulfide clusters reduces the calculated threshold velocity from the value predicted for a uniform distribution of sulfides. Calculations are compared with experimental results where the threshold velocity has been measured, and the predicted wide range of threshold values for steels of similar sulfur content but varying sulfide morphology is observed. The threshold velocity decreases with the increasing maximum sulfide particle size, qualitatively consistent with the theory. The calculation provides a basis for a conservative minimum velocity threshold tied directly to the steel sulfur level, in cases where no details of sulfide distribution are known.

  2. Neutron Star Population Dynamics.II: 3D Space Velocities of Young Pulsars

    E-Print Network [OSTI]

    J. M. Cordes; David F. Chernoff

    1997-07-28T23:59:59.000Z

    We use astrometric, distance and spindown data on pulsars to: (1) estimate three-dimensional velocity components, birth distances from the galactic plane, and ages of individual objects; (2) determine the distribution of space velocities and the scale height of pulsar progenitors; (3) test spindown laws for pulsars; (4) test for correlations between space velocities and other pulsar parameters; and (5) place empirical requirements on mechanisms than can produce high velocity neutron stars. Our approach incorporates measurement errors, uncertainties in distances, deceleration in the Galactic potential, and differential galactic rotation. We find that the scale height of the progenitors is approximately 0.13 kpc, that the 3D velocities are distributed in two components with characteristic speeds of 175(+20,-30) km/s and 700(+200,-150) km/s representing 83% and 17% of the population respectively. These results are insensitive to the explicit relation of chronological and spindown ages. We infer that the most probable chronological ages are typically smaller than conventional spindown ages by factors as large as two. We assess mechanisms for producing high-velocity neutron stars in view of the derived velocity distribution function.

  3. Propagation Plane waves -High order Modes

    E-Print Network [OSTI]

    Berlin,Technische Universität

    1 Propagation · Plane waves - High order Modes y x a One wave: p(x,y,t)=p0 cos(k y)e-jk x e j t vy(y,t)= 0 ; y=0,a xy } ky = n a Propagation · Plane waves - High order Modes x n a p(x,y,t)=pn cos( y + - +- + + - +- + - + + +- - - (m,n) #12;4 Propagation · Circular duct ­ Helical waves (spiralling waves) kc=m/a kz k

  4. Propagation Plane waves -High order Modes

    E-Print Network [OSTI]

    Berlin,Technische Universität

    1 Propagation · Plane waves - High order Modes y x a ky = n a One wave: p(x,y,t)=p0 cos(k y)e-jk x e j t vy(y,t)= 0 ; y=0,a xy } Propagation · Plane waves - High order Modes x n a p(x,y,t)=pn cos( y;4 Propagation · Circular duct ­ Helical waves (spiralling waves) kc=m/a kz kH Projection: Propagation #12

  5. VELOCITY AND MAGNETIC FIELD DISTRIBUTION IN A FORMING PENUMBRA

    SciTech Connect (OSTI)

    Romano, P.; Guglielmino, S. L. [INAF-Osservatorio Astrofisico di Catania, Via S. Sofia 78, I-95125 Catania (Italy); Frasca, D.; Zuccarello, F. [Dipartimento di Fisica e Astronomia-Sezione Astrofisica, Universita di Catania, Via S. Sofia 78, I-95125 Catania (Italy); Ermolli, I. [INAF-Osservatorio Astronomico di Roma, Via Frascati 33, I-00040 Monte Porzio Catone (Italy); Tritschler, A.; Reardon, K. P., E-mail: prom@oact.inaf.it [National Solar Observatory/Sacramento Peak, P.O. Box 62, Sunspot, NM 88349-0062 (United States)

    2013-07-01T23:59:59.000Z

    We present results from the analysis of high-resolution spectropolarimetric and spectroscopic observations of the solar photosphere and chromosphere, obtained shortly before the formation of a penumbra in one of the leading polarity sunspots of NOAA active region 11490. The observations were performed at the Dunn Solar Telescope of the National Solar Observatory on 2012 May 28, using the Interferometric Bidimensional Spectrometer. The data set is comprised of a 1 hr time sequence of measurements in the Fe I 617.3 nm and Fe I 630.25 nm lines (full Stokes polarimetry) and in the Ca II 854.2 nm line (Stokes I only). We perform an inversion of the Fe I 630.25 nm Stokes profiles to derive magnetic field parameters and the line-of-sight (LOS) velocity at the photospheric level. We characterize chromospheric LOS velocities by the Doppler shift of the centroid of the Ca II 854.2 nm line. We find that, before the formation of the penumbra, an annular zone of 3''-5'' width is visible around the sunspot. In the photosphere, we find that this zone is characterized by an uncombed structure of the magnetic field although no visible penumbra has formed yet. We also find that the chromospheric LOS velocity field shows several elongated structures characterized by downflow and upflow motions in the inner and outer parts of the annular zone, respectively.

  6. Terminal velocities of luminous, early-type SMC stars

    E-Print Network [OSTI]

    C. J. Evans; D. J. Lennon; C. Trundle; S. R. Heap; D. J. Lindler

    2004-03-12T23:59:59.000Z

    Ultraviolet spectra from the Space Telescope Imaging Spectrograph (STIS) are used to determine terminal velocities for 11 O and B-type giants and supergiants in the Small Magellanic Cloud (SMC) from the Si IV and C IV resonance lines. Using archival data from observations with the Goddard High-Resolution Spectrograph and the International Ultraviolet Explorer telescope, terminal velocities are obtained for a further five B-type supergiants. We discuss the metallicity dependence of stellar terminal velocities, finding no evidence for a significant scaling between Galactic and SMC metallicities for Teff < 30,000 K, consistent with the predictions of radiation driven wind theory for supergiant stars. A comparison of the $v_\\infty / v_{esc}$ ratio between the SMC and Galactic samples, while consistent with the above statement, emphasizes that the uncertainties in the distances to galactic O-stars are a serious obstacle to a detailed comparison with theory. For the SMC sample there is considerable scatter in this ratio at a given effective temperature, perhaps indicative of uncertainties in stellar masses.

  7. PERFORMANCE EFFECTS OF AIR VELOCITY PROFILES IN

    E-Print Network [OSTI]

    PERFORMANCE EFFECTS OF AIR VELOCITY PROFILES IN A RESIDENTIAL HEAT PUMP By NATHAN ANDREW WEBER PROFILES IN A RESIDENTIAL HEAT PUMP Thesis Approved: _______________________________________ Thesis Advisor the air speed transducer mount and the Plexiglas model of the heat pump. Ipseng Iu and myself worked side

  8. A MAGNETIC CALIBRATION OF PHOTOSPHERIC DOPPLER VELOCITIES

    SciTech Connect (OSTI)

    Welsch, Brian T.; Fisher, George H. [Space Sciences Laboratory, University of California, Berkeley, CA 94720-7450 (United States); Sun, Xudong [W. W. Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305 (United States)

    2013-03-10T23:59:59.000Z

    The zero point of measured photospheric Doppler shifts is uncertain for at least two reasons: instrumental variations (from, e.g., thermal drifts); and the convective blueshift, a known correlation between intensity and upflows. Accurate knowledge of the zero point is, however, useful for (1) improving estimates of the Poynting flux of magnetic energy across the photosphere, and (2) constraining processes underlying flux cancellation, the mutual apparent loss of magnetic flux in closely spaced, opposite-polarity magnetogram features. We present a method to absolutely calibrate line-of-sight (LOS) velocities in solar active regions (ARs) near disk center using three successive vector magnetograms and one Dopplergram coincident with the central magnetogram. It exploits the fact that Doppler shifts measured along polarity inversion lines (PILs) of the LOS magnetic field determine one component of the velocity perpendicular to the magnetic field, and optimizes consistency between changes in LOS flux near PILs and the transport of transverse magnetic flux by LOS velocities, assuming that ideal electric fields govern the magnetic evolution. Previous calibrations fitted the center-to-limb variation of Doppler velocities, but this approach cannot, by itself, account for residual convective shifts at the limb. We apply our method to vector magnetograms of AR 11158, observed by the Helioseismic and Magnetic Imager aboard the Solar Dynamics Observatory, and find clear evidence of offsets in the Doppler zero point in the range of 50-550 m s{sup -1}. In addition, we note that a simpler calibration can be determined from an LOS magnetogram and Dopplergram pair from the median Doppler velocity among all near-disk-center PIL pixels. We briefly discuss shortcomings in our initial implementation, and suggest ways to address these. In addition, as a step in our data reduction, we discuss the use of temporal continuity in the transverse magnetic field direction to correct apparently spurious fluctuations in resolution of the 180 Degree-Sign ambiguity.

  9. Drift velocity of electrons in quantum wells of selectively doped In{sub 0.5}Ga{sub 0.5}As/Al{sub x}In{sub 1-x}As and In{sub 0.2}Ga{sub 0.8}As/Al{sub x}Ga{sub 1-x}As heterostructures in high electric fields

    SciTech Connect (OSTI)

    Pozela, J., E-mail: pozela@pfi.lt; Pozela, K.; Raguotis, R.; Juciene, V. [Center for Physical Sciences and Technology, Semiconductor Physics Institute (Lithuania)

    2011-06-15T23:59:59.000Z

    The field dependence of drift velocity of electrons in quantum wells of selectively doped In{sub 0.5}Ga{sub 0.5}As/Al{sub x}In{sub 1-x}As and In{sub 0.2}Ga{sub 0.8}As/Al{sub x}Ga{sub 1-x}As heterostructures is calculated by the Monte Carlo method. The influence of varying the molar fraction of Al in the composition of the Al{sub x}Ga{sub 1-x}As and Al{sub x}In{sub 1-x}As barriers of the quantum well on the mobility and drift velocity of electrons in high electric fields is studied. It is shown that the electron mobility rises as the fraction x of Al in the barrier composition is decreased. The maximum mobility in the In{sub 0.5}Ga{sub 0.5}As/In{sub 0.8}Al{sub 0.2}As quantum wells exceeds the mobility in a bulk material by a factor of 3. An increase in fraction x of Al in the barrier leads to an increase in the threshold field E{sub th} of intervalley transfer (the Gunn effect). The threshold field is E{sub th} = 16 kV/cm in the In{sub 0.5}Ga{sub 0.5}As/Al{sub 0.5}In{sub 0.5}As heterostructures and E{sub th} = 10 kV/cm in the In{sub 0.2}Ga{sub 0.8}As/Al{sub 0.3}Ga{sub 0.7}As heterostructures. In the heterostructures with the lowest electron mobility, E{sub th} = 2-3 kV/cm, which is lower than E{sub th} = 4 kV/cm in bulk InGaAs.

  10. Reconstructing the WIMP Velocity Distribution from Direct Dark Matter Detection Data with a Non-negligible Threshold Energy

    E-Print Network [OSTI]

    Shan, Chung-Lin

    2015-01-01T23:59:59.000Z

    In this paper, we investigate the modification of our expressions developed for the model-independent data analysis procedure of the reconstruction of the (time-averaged) one-dimensional velocity distribution of Galactic Weakly Interacting Massive Particles (WIMPs) with a non-negligible experimental threshold energy. Our numerical simulations show that, for a minimal reconstructable velocity of as high as O(200) km/s, our model-independent modification of the estimator for the normalization constant could provide precise reconstructed velocity distribution points to match the true WIMP velocity distribution with a <~ 10% bias.

  11. Relativistic equilibrium velocity distribution, nuclear fusion reaction rate and the solar neutrino problem

    E-Print Network [OSTI]

    Jian-Miin Liu

    2003-07-07T23:59:59.000Z

    In solar interior, it is the equilibrium velocity distribution of few high-energy protons and nuclei that participates in determining nuclear fusion reaction rates. So, it is inappropriate to use the Maxwellian velocity distribution to calculate the rates of solar nuclear fusion reactions. We have to use the relativistic equilibrium velocity distribution for the purpose. The nuclear fusion reaction rate based on the relativistic equilibrium velocity distribution has a reduction factor with respect to that based on the Maxwellian distribution. The reduction factor depends on the temperature, reduced mass and atomic numbers of the studied nuclear fusion reactions, in other words, it varies with the sort of neutrinos. Substituting the relativistic equilibrium velocity distribution for the Maxwellian distribution is not important for the calculation of solar sound speeds. The relativistic equilibrium velocity distribution, if adopted in standard solar models, will lower solar neutrino fluxes and change solar neutrino energy spectra but maintain solar sound speeds. This velocity distribution is possibly a solution to the solar neutrino problem.

  12. Percutaneous Transhepatic Biliary Drainage in the Management of Postsurgical Biliary Leaks in Patients with Nondilated Intrahepatic Bile Ducts

    SciTech Connect (OSTI)

    Cozzi, Guido, E-mail: guido.cozzi@istitutotumori.mi.it; Severini, Aldo; Civelli, Enrico; Milella, Marco [National Cancer Institute (Istituto Nazionale Tumori), Department of Radiology, Radiologia 3 Unit (Italy); Pulvirenti, Andrea [National Cancer Institute (Istituto Nazionale Tumori), Department of Surgery, Gastrointestinal Surgery and Liver Transplantation Unit (Italy); Salvetti, Monica [National Cancer Institute (Istituto Nazionale Tumori), Department of Radiology, Radiologia 3 Unit (Italy); Romito, Raffaele [National Cancer Institute (Istituto Nazionale Tumori), Department of Surgery, Gastrointestinal Surgery and Liver Transplantation Unit (Italy); Suman, Laura; Chiaraviglio, Francesca [National Cancer Institute (Istituto Nazionale Tumori), Department of Radiology, Radiologia 3 Unit (Italy); Mazzaferro, Vincenzo [National Cancer Institute (Istituto Nazionale Tumori), Department of Surgery, Gastrointestinal Surgery and Liver Transplantation Unit (Italy)

    2006-06-15T23:59:59.000Z

    Purpose. To assess the feasibility of percutaneous transhepatic biliary drainage (PTBD) for the treatment of postsurgical biliary leaks in patients with nondilated intrahepatic bile ducts, its efficacy in restoring the integrity of bile ducts, and technical procedures to reduce morbidity. Methods. Seventeen patients out of 936 undergoing PTBD over a 20-year period had a noncholestatic liver and were retrospectively reviewed. All patients underwent surgery for cancer and suffered a postsurgical biliary leak of 345 ml/day on average; 71% were in poor condition and required permanent nutritional support. An endoscopic approach failed or was excluded due to inaccessibility of the bile ducts. Results. Established biliary leaks and site of origin were diagnosed an average of 21 days (range 1-90 days) after surgery. In all cases percutaneous access to the biliary tree was achieved. An external (preleakage) drain was applied in 7 cases, 9 patients had an external-internal fistula bridging catheter, and 1 patient had a percutaneous hepatogastrostomy. Fistulas healed in an average of 31 days (range 3-118 days ) in 15 of 17 patients (88%) following PTBD. No major complications occurred after drainage. Post-PTBD cholangitis was observed in 6 of 17 patients (35%) and was related to biliary sludge formation occurring mostly when drainage lasted >30 days and was of the external-internal type. Median patient survival was 17.7 months and in all cases the repaired biliary leaks remained healed. Conclusions. PTBD is a feasible, effective, and safe procedure for the treatment of postsurgical biliary leaks. It is therefore a reliable alternative to surgical repair, which entails longer hospitalization and higher costs.

  13. Centerline velocity profile for plain round exhaust hoods

    E-Print Network [OSTI]

    Martin, Kirksey E

    1977-01-01T23:59:59.000Z

    , System 2, . . . 52 Appendix D ? Statistical Analysis Tables . . . . , . . . , . 63 ITA ~ ~ ~ ~ ~ ~ ~ o o ~ ~ i ~ ~ ~ ~ ~ ~ V ~ ~ ~ Q I ~ ~ 0 Q ~ ~ ~ 66 LIST OF FIBURES Fi gure 1 Air Flow into Simple Hood Page 2 Compound Hood 3 Duct Air Moni tor.... ' ' ' However, if 2,6, 7,8 Sil verman's model were correct, contaminant control would be maintained with significantly reduced exhaust volumes. Local exhaust system de- sign, based on this reduced volume, cpu]d result in substantial savings in equipment...

  14. Comment on "Pulsar Velocities and Neutrino Oscillations"

    E-Print Network [OSTI]

    Y. -Z. Qian

    1997-05-08T23:59:59.000Z

    In a recent Letter, Kusenko and Segre proposed a new mechanism to explain the observed proper motions of pulsars. Their mechanism was based on the asymmetric neutrino emission induced by neutrino oscillations in the protoneutron star magnetic field. In this note I point out that their estimate of the asymmetry in the neutrino emission is incorrect. A proper calculation shows that their mechanism at least requires a magnetic field of 10**16 G in order to produce the observed average pulsar velocity.

  15. On Pulsar Velocities from Neutrino Oscillations

    E-Print Network [OSTI]

    Michael Birkel; Ramon Toldra

    1997-06-11T23:59:59.000Z

    It has been recently suggested that magnetically affected neutrino oscillations inside a cooling protoneutron star, created in a supernova explosion, could explain the large proper motion of pulsars. We investigate whether this hypothesis is in agreement with the observed properties of pulsars and find that present data disfavor the suggested mechanism. The relevance of our results for other models proposed to understand the origin of pulsar velocities is also discussed.

  16. Slow group velocity and Cherenkov radiation

    E-Print Network [OSTI]

    I. Carusotto; M. Artoni; G. C. La Rocca; F. Bassani

    2001-03-12T23:59:59.000Z

    We theoretically study the effect of ultraslow group velocities on the emission of Vavilov-Cherenkov radiation in a coherently driven medium. We show that in this case the aperture of the group cone on which the intensity of the radiation peaks is much smaller than that of the usual wave cone associated with the Cherenkov coherence condition. We show that such a singular behaviour may be observed in a coherently driven ultracold atomic gas.

  17. Irregular wave induced velocities in shallow water

    E-Print Network [OSTI]

    Sultan, Nels John

    1991-01-01T23:59:59.000Z

    probabil- ity density function. This thesis applies this expanded distribution to fluid particle velocities instead of wave elevations. Ochi (1982) presents a review of recent ad- vances in the stochastic analysis of random seas. He notes that the first..., (Longuet-Higgins 1963), that purely linear waves will have a Gaussian distribu- tion. Therefore, any deviation from a Gaussian distribution must be attributed to wave nonlinearities. Ochi (1982) discusses a series of experiments by Honda and Mitsuyasu...

  18. Temperature dependent sound velocity in hydrodynamic equations for relativistic heavy-ion collisions

    E-Print Network [OSTI]

    Mikolaj Chojnacki

    2007-09-11T23:59:59.000Z

    We analyze the effects of different forms of the sound-velocity function cs(T) on the hydrodynamic evolution of matter formed in the central region of relativistic heavy-ion collisions. At high temperatures (above the critical temperature Tc) the sound velocity is calculated from the recent lattice simulations of QCD, while in the low temperature region it is obtained from the hadron gas model. In the intermediate region we use different interpolations characterized by the values of the sound velocity at the local maximum (at T = 0.4 Tc) and local minimum (at T = Tc). In all considered cases the temperature dependent sound velocity functions yield the entropy density, which is consistent with the lattice QCD simulations at high temperature. Our calculations show that the presence of a distinct minimum of the sound velocity leads to a very long (about 20 fm/c) evolution time of the system, which is not compatible with the recent estimates based on the HBT interferometry. Hence, we conclude that the hydrodynamic description is favored in the case where the cross-over phase transition renders the smooth sound velocity function with a possible shallow minimum at Tc.

  19. Constraining Spiral Structure Parameters through Galactic Pencil-beam and Large-scale Radial Velocity Surveys

    E-Print Network [OSTI]

    I. Minchev; A. Quillen

    2007-10-26T23:59:59.000Z

    We investigate the effect of spiral structure on the Galactic disk as viewed by pencil beams centered on the Sun, relevant to upcoming surveys such as ARGOS, SEGUE, and GAIA. We create synthetic Galactic maps which we call Pencil Beam Maps (PBMs) of the following observables: line-of-sight velocities, the corresponding velocity dispersion, and the stellar number density that are functions of distance from the observer. We show that such maps can be used to infer spiral structure parameters, such as pattern speed, solar phase angle, and number of arms. The mean line-of-sight velocity and velocity dispersion are affected by up to ~35 km/s which is well within the detectable limit for forthcoming radial velocity surveys. One can measure the pattern speed by searching for imprints of resonances. In the case of a two-armed spiral structure it can be inferred from the radius of a high velocity dispersion ring situated at the 2:1 ILR. This information, however, must be combined with information related to the velocities and stellar number density in order to distinguish from a four-armed structure. If the pattern speed is such that the 2:1 ILR is hidden inside the Galactic bulge the 2:1 OLR will be present in the outer Galaxy and thus can equivalently be used to estimate the pattern speed. Once the pattern speed is known the solar angle can be estimated from the line-of-sight velocities and the number density PBMs. Forthcoming radial velocity surveys are likely to provide powerful constraints of the structure of the Milky Way disk.

  20. The nuclear fusion reaction rate based on relativistic equilibrium velocity distribution

    E-Print Network [OSTI]

    Jian-Miin Liu

    2002-10-20T23:59:59.000Z

    The Coulomb barrier is in general much higher than thermal energy. Nuclear fusion reactions occur only among few protons and nuclei with higher relative energies than Coulomb barrier. It is the equilibrium velocity distribution of these high-energy protons and nuclei that participates in determining the rate of nuclear fusion reactions. In the circumstance it is inappropriate to use the Maxwellian velocity distribution for calculating the nuclear fusion reaction rate. We use the relativistic equilibrium velocity distribution for this purpose. The rate based on the relativistic equilibrium velocity distribution has a reduction factor with respect to that based on the Maxwellian distribution, which factor depends on the temperature, reduced mass and atomic numbers of the studied nuclear fusion reactions. This signifies much to the solar neutrino problem.

  1. On the velocity-strengthening behavior of dry friction

    E-Print Network [OSTI]

    Bar-Sinai, Yohai; Brener, Efim A; Bouchbinder, Eran

    2013-01-01T23:59:59.000Z

    The onset of frictional instabilities, e.g. earthquakes nucleation, is intimately related to velocity-weakening friction, in which the frictional resistance of interfaces decreases with increasing slip velocity. While this frictional response has been studied extensively, much less attention has been given to steady-state velocity-strengthening friction, in spite of its importance for various aspects of frictional phenomena such as the propagation speed of interfacial rupture fronts and the amount of stored energy released by them. In this note we suggest that a crossover from steady-state velocity-weakening friction at small slip velocities to steady-state velocity-strengthening friction at higher velocities might be a generic feature of dry friction. We further argue that while thermally activated rheology naturally gives rise to logarithmic steady-state velocity-strengthening friction, a crossover to stronger-than-logarithmic strengthening might take place at higher slip velocities, possibly accompanied by...

  2. Scaleup tests and supporting research for the development of duct injection technology. Topical report No. 2, Task 3.1: Evaluation of system performance, Duct Injection Test Facility, Muskingum River Power Plant, Beverly, Ohio

    SciTech Connect (OSTI)

    Felix, L.G.; Dismukes, E.B.; Gooch, J.P. [Southern Research Inst., Birmingham, AL (United States); Klett, M.G.; Demian, A.G. [Gilbert/Commonwealth, Inc., Reading, PA (United States)

    1992-04-20T23:59:59.000Z

    This Topical Report No. 2 is an interim report on the Duct Injection Test Facility being operated for the Department of Energy at Beverly, Ohio. Either dry calcium hydroxide or an aqueous slurry of calcium hydroxide (prepared by slaking quicklime) is injected into a slipstream of flue gas to achieve partial removal of SO{sub 2} from a coal-burning power station. Water injected with the slurry or injected separately from the dry sorbents cools the flue gas and increases the water vapor content of the gas. The addition of water, either in the slurry or in a separate spray, makes the extent of reaction between the sorbent and the SO{sub 2} more complete; the presumption is that water is effective in the liquid state, when it is able to wet the sorbent particles physically, and not especially effective in the vapor state. An electrostatic precipitator collects the combination of suspended solids (fly ash from the boiler and sorbent from the duct injection process). All of the operations are being carried out on the scale of approximately 50,000 acfm of flue gas.

  3. Unexplored Aspect of Velocity of light

    E-Print Network [OSTI]

    Abhijit Biswas; Krishnan RS Mani

    2008-05-13T23:59:59.000Z

    In the post-Maxwellian era, sensing that the tide of discoveries in electromagnetim indicated a decline of the mechanical view, Einstein replaced Newton's three absolutes -- space, time and mass, with a single one, the velocity of light. The magnitude of the velocity of light was first determined and proven to be finite independently by Ole Romer and Bradley in the eighteenth century. In the nineteenth century, Fizeau carried out the first successful measurement of the speed of light using an earthbound apparatus. Thereafter, many earthbound experiments were conducted for its determination till 1983, when its magnitude was frozen at a fixed value after it was determined up to an accuracy level of a fraction of a meter per second. Einstein considered the speed of light derived from terrestrial experiments, to be the limiting speed of all natural phenomena. Einstein stated in connection with his general relativity theory that light rays could curve only when the velocity of propagation of light varies with position. Experiments have been conducted to prove the phenomenon of light deflection to higher and higher accuracy levels, but none so far to determine the speed of light at locations closer to the sun. To verify some essential aspects of general relativity, NASA had commendably planned many costly experiments. Hence, NASA can now be expected to expeditiously plan and execute the low cost experiment proposed here, so as to conclusively verify the effect of the solar gravitational field on the speed of light, as regards the important predictions of Einstein's theory of gravitation and of its remodeled form -- the Remodeled Relativity Theory, which retained and incorporated only experimentally proven concepts and principles.

  4. Cleanup and Dismantling of Highly Contaminated Ventilation Systems Using Robotic Tools - 13162

    SciTech Connect (OSTI)

    Chambon, Frederic [AREVA FEDERAL SERVICES, Columbia MD (United States)] [AREVA FEDERAL SERVICES, Columbia MD (United States); CIZEL, Jean-Pierre [AREVA BE/NV, Marcoule (France)] [AREVA BE/NV, Marcoule (France); Blanchard, Samuel [CEA DEN/DPAD, Marcoule (France)] [CEA DEN/DPAD, Marcoule (France)

    2013-07-01T23:59:59.000Z

    The UP1 plant reprocessed nearly 20,000 tons of used natural uranium gas cooled reactor fuel coming from the first generation of civil nuclear reactors in France. Following operating incidents in the eighties, the ventilation system of the continuous dissolution line facility was shut down and replaced. Two types of remote controlled tool carriers were developed to perform the decontamination and dismantling operations of the highly contaminated ventilation duct network. The first one, a dedicated small robot, was designed from scratch to retrieve a thick powder deposit within a duct. The robot, managed and confined by two dedicated glove boxes, was equipped for intervention inside the ventilation duct and used for carrying various cleanup and inspection tools. The second type, consisting of robotic tools developed on the base of an industrial platform, was used for the clean-up and dismantling of the ventilation duct system. Depending on the type of work to be performed, on the shape constraints of the rooms and any equipment to be dismantled, different kinds of robotic tools were developed and installed on a Brokk 40 carrier. After more than ten years of ventilation duct D and D operations at the UP1 plant, a lot of experience was acquired about remote operations. The three main important lessons learned in terms of remote controlled operation are: characterizing the initial conditions as much as reasonably possible, performing non-radioactive full scale testing and making it as simple and modular as possible. (authors)

  5. Velocity-selected molecular pulses produced by an electric guide

    SciTech Connect (OSTI)

    Sommer, C.; Motsch, M.; Chervenkov, S.; Buuren, L. D. van; Zeppenfeld, M.; Pinkse, P. W. H.; Rempe, G. [Max-Planck-Institut fuer Quantenoptik, Hans-Kopfermann-Str. 1, D-85748 Garching (Germany)

    2010-07-15T23:59:59.000Z

    Electrostatic velocity filtering is a technique for the production of continuous guided beams of slow polar molecules from a thermal gas. We extended this technique to produce pulses of slow molecules with a narrow velocity distribution around a tunable velocity. The pulses are generated by sequentially switching the voltages on adjacent segments of an electric quadrupole guide synchronously with the molecules propagating at the desired velocity. This technique is demonstrated for deuterated ammonia (ND{sub 3}), delivering pulses with a velocity in the range of 20-100 m/s and a relative velocity spread of (16{+-}2)% at full width at half maximum. At velocities around 60 m/s, the pulses contain up to 10{sup 6} molecules each. The data are well reproduced by Monte Carlo simulations, which provide useful insight into the mechanisms of velocity selection.

  6. Particle deposition from turbulent flow: Review of published research and its applicability to ventilation ducts in commercial buildings

    E-Print Network [OSTI]

    Sippola, Mark R.; Nazaroff, William W.

    2002-01-01T23:59:59.000Z

    equation (51), kg m s -2 thermophoretic force on a particle,equation (74) thermophoretic force coefficient, equation (equation (50), m s -1 thermophoretic velocity of a particle,

  7. Orthogonal-Phase-Velocity Propagation of Electromagnetic Plane Waves

    E-Print Network [OSTI]

    Tom G. Mackay; Akhlesh Lakhtakia

    2005-11-30T23:59:59.000Z

    In an isotropic, homogeneous, nondissipative, dielectric-magnetic medium that is simply moving with respect to an inertial reference frame, planewave solutions of the Maxwell curl postulates can be such that the phase velocity and the time-averaged Poynting vector are mutually orthogonal. Orthogonal-phase-velocity propagation thus adds to the conventional positive-phase-velocity propagation and the recently discovered negative-phase-velocity propagation that is associated with the phenomenon of negative refraction.

  8. Experimental investigation of velocity biasing in laser Doppler anemometry

    E-Print Network [OSTI]

    Wiedner, Brian Gregory

    1988-01-01T23:59:59.000Z

    Tech University; Chair of Advisory Commettee: Dr. Gerald L. Morrison The effects of several velocity bias reduction schemes were invest- igated using a 3-D laser Doppler anemometer and counter type (burst) signal processors. Amongst these schemes... of Sample Size on Effects of Sample Size on Effects of Sample Size on Effects of Sample Size on Velocity and Reynolds Stresses Axial Mean Velocity Radial Mean Velocity Axial Turbulence Intensity Radial Turbulence Intensity Axial/Radial Correlation...

  9. Velocity and attenuation in partially molten rocks

    SciTech Connect (OSTI)

    Mavko, G.M.

    1980-10-10T23:59:59.000Z

    Interpretation of seismic velocity and attenuation in partially molten rocks has been limited, with few exceptions, to models that assume the melt to be distributed either as spheres or as thin films. However, other melt phase geometries, such as interconnected tubes along grain edges, might equally well account for seismic observations if there is a much larger fraction of melt. Seismic velocity and attenuation are estimated in rocks in which the melt phase has the tube geometry, and the results are compared with results expected for the more familiar film model under similar conditions. For a given melt fraction, tubes are found to give moduli intermediate between moduli for rigid spherical inclusions and compliant films. For example, in polycrystalline olivine at 20 kbar the model predicts a decrease in V/sub s/ of 10% and a decrease in V/sub p/ of 5% at 0.05 melt fraction, without considering inelastic relaxation. Shear attenuation appears to be dominated by viscous flow of melt between the tubes and/or films. For olivine the tube model predicts the increment of relaxation due to melt, ..delta mu../..mu.., to be 0.01 at 0.05 melt fraction. Relaxation of the bulk modulus is dominated by flow between melt pockets of different shape, heat flow, and solid-melt phase change. If melt is present, considerable bulk attenuation is expected, although the relaxation may be observable only at long periods, outside the seismic body wave band.

  10. Seismic Velocity Estimation from Time Migration Maria Kourkina Cameron

    E-Print Network [OSTI]

    Cameron, Maria Kourkina

    Seismic Velocity Estimation from Time Migration by Maria Kourkina Cameron Diplom (Moscow Institute Dung-Hai Lee Spring 2007 #12;Seismic Velocity Estimation from Time Migration Copyright c 2007 by Maria Kourkina Cameron #12;Abstract Seismic Velocity Estimation from Time Migration by Maria Kourkina Cameron

  11. CONVERGENT FLOWS AND LOW-VELOCITY SHOCKS IN DR21(OH)

    SciTech Connect (OSTI)

    Csengeri, T. [Max Planck Institute for Radioastronomy, Auf dem Huegel 69, 53121 Bonn (Germany); Bontemps, S. [OASU/LAB-UMR5804, CNRS, Universite Bordeaux 1, 33270 Floirac (France); Schneider, N.; Motte, F. [Laboratoire AIM Paris Saclay, CEA-INSU/CNRS-Universite Paris Diderot, IRFU/SAp CEA-Saclay, 91191 Gif-sur-Yvette (France); Gueth, F. [IRAM, 300 rue de la piscine, 38406, Saint Martin d'Heres (France); Hora, J. L., E-mail: ctimea@mpifr-bonn.mpg.de [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS-65, Cambridge, MA 02138 (United States)

    2011-10-10T23:59:59.000Z

    DR21(OH) is a pc-scale massive, {approx}7000 M{sub sun} clump hosting three massive dense cores (MDCs) at an early stage of their evolution. We present a high angular resolution mosaic, covering {approx}70'' x 100'', with the IRAM Plateau de Bure Interferometer at 3 mm to trace the dust continuum emission and the N{sub 2}H{sup +} (J = 1-0) and CH{sub 3}CN (J = 5-4) molecular emission. The cold, dense gas traced by the compact emission in N{sub 2}H{sup +} is associated with the three MDCs and shows several velocity components toward each MDC. These velocity components reveal local shears in the velocity fields which are best interpreted as convergent flows. Moreover, we report the detection of weak extended emission from CH{sub 3}CN at the position of the N{sub 2}H{sup +} velocity shears. We propose that this extended CH{sub 3}CN emission is tracing warm gas associated with the low-velocity shocks expected at the location of convergence of the flows where velocity shears are observed. This is the first detection of low-velocity shocks associated with small (subparsec) scale convergent flows which are proposed to be at the origin of the densest structures and of the formation of (high-mass) stars. In addition, we propose that MDCs may be active sites of star formation for more than a crossing time as they continuously receive material from larger scale flows as suggested by the global picture of dynamical, gravity-driven evolution of massive clumps which is favored by the present observations.

  12. Force-velocity relations for multiple molecular motor transportation

    E-Print Network [OSTI]

    Wang, Ziqing

    2009-01-01T23:59:59.000Z

    A transition rate model of cargo transportation by N effective molecular motors is proposed. Under the assumption of steady state, the force-velocity curve of multi-motor system can be derived from the force-velocity curve of single motor. Our work shows, in the case of low load, the velocity of multi-motor system can decrease or increase with increasing motor number, which is dependent on the single motor force-velocity curve. And most commonly, the velocity decreases. This gives a possible explanation to some recent experimental observations.

  13. Force-velocity relations for multiple-molecular-motor transport

    E-Print Network [OSTI]

    Ziqing Wang; Ming Li

    2009-10-01T23:59:59.000Z

    A transition rate model of cargo transport by $N$ molecular motors is proposed. Under the assumption of steady state, the force-velocity curve of multi-motor system can be derived from the force-velocity curve of single motor. Our work shows, in the case of low load, the velocity of multi-motor system can decrease or increase with increasing motor number, which is dependent on the single motor force-velocity curve. And most commonly, the velocity decreases. This gives a possible explanation to some recent

  14. 12th AIAA/CEAS Aeroacoustics Conference, 8-10 May 2006, Cambridge, MA, USA Sound Radiation from an Annular Duct with Jet Flow

    E-Print Network [OSTI]

    Eindhoven, Technische Universiteit

    an Annular Duct with Jet Flow and a Lined Centerbody A. Demir Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands. S.W. Rienstra Eindhoven University of Technology, 5600 MB Eindhoven, in particular the afterbody. Post-doctoral Researcher, Department of Mathematics & Computer Science, Eindhoven

  15. In Proc. 1996 ACEEE Summer Study, August 1996, Asilomar, CA. Energy Effectiveness of Duct Sealing and Insulation in Two Multifamily Buildings

    E-Print Network [OSTI]

    Norwalk, Connecticut SYNOPSIS This paper discusses field measurements from five apartments in New York1 LBL# 38538 In Proc. 1996 ACEEE Summer Study, August 1996, Asilomar, CA. Energy Effectiveness that were monitored to determine the effect of duct retrofits on energy use. ABSTRACT Energy losses from

  16. In Proc. 1996 ACEEE Summer Study, August 1996, Asilomar, CA Field Measurements of Efficiency and Duct Retrofit Effectiveness in Residential Forced air

    E-Print Network [OSTI]

    consumption. These data were used to calculate distribution system delivery efficiency as well as the overall% reduction in heating energy consumption. · Cummings et al. performed pre- and post-duct retrofit. The systems in these houses included conventional air conditioning, gas furnaces, electric furnaces and heat

  17. Scaling of convective velocity in a vertically vibrated granular bed

    E-Print Network [OSTI]

    Tomoya M. Yamada; Hiroaki Katsuragi

    2014-05-30T23:59:59.000Z

    We experimentally study the velocity scaling of granular convection which is a possible mechanism of the regolith migration on the surface of small asteroids. In order to evaluate the contribution of granular convection to the regolith migration, the velocity of granular convection under the microgravity condition has to be revealed. Although it is hard to control the gravitational acceleration in laboratory experiments, scaling relations involving the gravitational effect can be evaluated by systematic experiments. Therefore, we perform such a systematic experiment of the vibration-induced granular convection. From the experimental data, a scaling form for the granular convective velocity is obtained. The obtained scaling form implies that the granular convective velocity can be decomposed into two characteristic velocity components: vibrational and gravitational velocities. In addition, the system size dependence is also scaled. According to the scaling form, the granular convective velocity $v$ depends on the gravitational acceleration $g$ as $v \\propto g^{0.97}$ when the normalized vibrational acceleration is fixed.

  18. Filament velocity scaling laws for warm ions

    SciTech Connect (OSTI)

    Manz, P. [Physik-Department E28, Technische Universität München, James-Franck-Str. 1, 85748 Garching (Germany) [Physik-Department E28, Technische Universität München, James-Franck-Str. 1, 85748 Garching (Germany); Max-Planck-Institut für Plasmaphysik, EURATOM Assoziation, Boltzmannstr. 2, 85748 Garching (Germany); Carralero, D.; Birkenmeier, G.; Müller, H. W.; Scott, B. D. [Max-Planck-Institut für Plasmaphysik, EURATOM Assoziation, Boltzmannstr. 2, 85748 Garching (Germany)] [Max-Planck-Institut für Plasmaphysik, EURATOM Assoziation, Boltzmannstr. 2, 85748 Garching (Germany); Müller, S. H. [Center for Momentum Transport and Flow Organization, University of California at San Diego, San Diego 92093 (United States)] [Center for Momentum Transport and Flow Organization, University of California at San Diego, San Diego 92093 (United States); Fuchert, G. [Insitut für Grenzflächenverfahrenstechnik und Plasmatechnologie, Universität Stuttgart, 70569 Stuttgart (Germany)] [Insitut für Grenzflächenverfahrenstechnik und Plasmatechnologie, Universität Stuttgart, 70569 Stuttgart (Germany); Stroth, U. [Max-Planck-Institut für Plasmaphysik, EURATOM Assoziation, Boltzmannstr. 2, 85748 Garching (Germany) [Max-Planck-Institut für Plasmaphysik, EURATOM Assoziation, Boltzmannstr. 2, 85748 Garching (Germany); Physik-Department E28, Technische Universität München, James-Franck-Str. 1, 85748 Garching (Germany)

    2013-10-15T23:59:59.000Z

    The dynamics of filaments or blobs in the scrape-off layer of magnetic fusion devices are studied by magnitude estimates of a comprehensive drift-interchange-Alfvén fluid model. The standard blob models are reproduced in the cold ion case. Even though usually neglected, in the scrape-off layer, the ion temperature can exceed the electron temperature by an order of magnitude. The ion pressure affects the dynamics of filaments amongst others by adding up to the interchange drive and the polarisation current. It is shown how both effects modify the scaling laws for filament velocity in dependence of its size. Simplifications for experimentally relevant limit regimes are given. These are the sheath dissipation, collisional, and electromagnetic regime.

  19. Correlation of bubble rise velocity and volume

    SciTech Connect (OSTI)

    Burge, C.

    1991-12-31T23:59:59.000Z

    This project was conducted at Westinghouse`s Savannah River Laboratories (SRL). The goal of SRL is to make certain that the modifications on the reactor are safe for those working at the plant as well as the general public. One of the steps needed to insure safety is the knowledge of the occurrences that result from a plenum pipe breakage. When a plenum pipe breaks, two things occur: air is sucked into the pipe and is trapped in the cooling water; and water used to cool the fuel rods is lost. As a result of these occurrences, the water is slowed down by both the loss in water pressure and the upward force of air bubbles pushing against the downward force of the water. The project required the conducting of tests to find the bubble velocity in an annular ribbed pipe filled with stagnant water. This document discusses the methodology and results of this testing.

  20. Correlation of bubble rise velocity and volume

    SciTech Connect (OSTI)

    Burge, C.

    1991-01-01T23:59:59.000Z

    This project was conducted at Westinghouse's Savannah River Laboratories (SRL). The goal of SRL is to make certain that the modifications on the reactor are safe for those working at the plant as well as the general public. One of the steps needed to insure safety is the knowledge of the occurrences that result from a plenum pipe breakage. When a plenum pipe breaks, two things occur: air is sucked into the pipe and is trapped in the cooling water; and water used to cool the fuel rods is lost. As a result of these occurrences, the water is slowed down by both the loss in water pressure and the upward force of air bubbles pushing against the downward force of the water. The project required the conducting of tests to find the bubble velocity in an annular ribbed pipe filled with stagnant water. This document discusses the methodology and results of this testing.

  1. Single-mode fiber, velocity interferometry

    SciTech Connect (OSTI)

    Krauter, K. G.; Jacobson, G. F.; Patterson, J. R.; Nguyen, J. H.; Ambrose, W. P. [Lawrence Livermore National Laboratory, 7000 East Ave., Livermore California 94551 (United States)

    2011-04-15T23:59:59.000Z

    In this paper, we describe a velocity interferometer system based entirely on single-mode fiber optics. This paper includes a description of principles used in developing the single-mode velocity interferometry system (SMV). The SMV design is based on polarization-insensitive components. Polarization adjusters are included to eliminate the effects of residual birefringence and polarization dependent losses in the interferometers. Characterization measurements and calibration methods needed for data analysis and a method of data analysis are described. Calibration is performed directly using tunable lasers. During development, we demonstrated its operation using exploding-foil bridge-wire fliers up to 200 m/s. In a final test, we demonstrated the SMV in a gas gun experiment up to 1.2 km/sec. As a basis for comparison in the gas gun experiment, we used another velocimetry technique that is also based on single-mode fiber optics: photonic Doppler velocimetry (PDV). For the gas gun experiment, we split the light returned from a single target spot and performed a direct comparison of the homodyne (SMV) and heterodyne (PDV) techniques concurrently. The two techniques had a negligible mean difference and a 1.5% standard deviation in the one-dimensional shock zone. Within one interferometer delay time after a sudden Doppler shift, a SMV unencumbered by multimode-fiber dispersion exhibits two color beats. These beats have the same period as PDV beats--this interference occurs between the ''recently'' shifted and ''formerly unshifted'' paths within the interferometer. We believe that recognizing this identity between homodyne and heterodyne beats is novel in the shock-physics field. SMV includes the conveniences of optical fiber, while removing the time resolution limitations associated with the multimode delivery fiber.

  2. Ensemble Kalman Filter Assimilation of Simulated HIWRAP Doppler Velocity Data in a Hurricane

    E-Print Network [OSTI]

    Ensemble Kalman Filter Assimilation of Simulated HIWRAP Doppler Velocity Data in a Hurricane JASON (Manuscript received 29 May 2012, in final form 16 January 2013) ABSTRACT This study utilizes ensemble Kalman Kalman filter (EnKF) assimilation of high-resolution observations from tropical cyclones can improve

  3. Author's personal copy Effects of crossflow velocity and transmembrane pressure on microfiltration

    E-Print Network [OSTI]

    Priezjev, Nikolai V.

    Author's personal copy Effects of crossflow velocity and transmembrane pressure on microfiltration, at the same time, high rejection rate of the oil phase. The effects of transmembrane pressure and crossflow-section are investigated numerically by solving the Navier­Stokes equation. We found that in the absence of crossflow

  4. Technical status report development of lime based in-duct scrubbing - A cost effective SO/sub 2/ control technology

    SciTech Connect (OSTI)

    Shilling, N.Z.; Samuel, E.A.; Pennline, H.

    1986-04-01T23:59:59.000Z

    Lime Based In-Duct Scrubbing (LIBIDS) was one of the candidate technologies receiving contract awards for pilot demonstration by the U.S. Department of Energy under the Acid Rain Precurser program. The concept as developed by General Electric utilizes rotary atomization of lime slurry directly within flue gas carrying ductwork to remove SO/sub 2/. This promises to be a very low capital cost method of SO/sub 2/ control with capital plus levelized operating cost estimated to be $364/KW. Several significant technical milestones have been passed relative to proof of principle and ultimate commercialization. Based on positive results from a laboratory and supporting analytical work, a detailed engineering design has begun for a pilot plant.

  5. Initial Examination of Low Velocity Sphere Impact of Glass Ceramics

    SciTech Connect (OSTI)

    Morrissey, Timothy G [ORNL; Fox, Ethan E [ORNL; Wereszczak, Andrew A [ORNL; Ferber, Mattison K [ORNL

    2012-06-01T23:59:59.000Z

    This report summarizes US Army TARDEC sponsored work at Oak Ridge National Laboratory (ORNL) involving low velocity (< 30 m/s or < 65 mph) sphere impact testing of two materials from the lithium aluminosilicate family reinforced with different amounts of ceramic particulate, i.e., glass-ceramic materials, SCHOTT Resistan{trademark}-G1 and SCHOTT Resistan{trademark}-L. Both materials are provided by SCHOTT Glass (Duryea, PA). This work is a follow-up to similar sphere impact studies completed by the authors on PPG's Starphire{reg_sign} soda-lime silicate glass and SCHOTT BOROFLOAT{reg_sign} borosilicate glass. A gas gun or a sphere-drop test setup was used to produce controlled velocity delivery of silicon nitride (Si{sub 3}N{sub 4}) spheres against the glass ceramic tile targets. Minimum impact velocities to initiate fracture in the glass-ceramics were measured and interpreted in context to the kinetic energy of impact and the elastic property mismatch between sphere and target material. Quasistatic spherical indentation was also performed on both glass ceramics and their contact damage responses were compared to those of soda-lime silicate and borosilicate glasses. Lastly, variability of contact damage response was assessed by performing spherical indentation testing across the area of an entire glass ceramic tile. The primary observations from this low velocity (< 30 m/s or < 65 mph) testing were: (1) Resistan{trademark}-L glass ceramic required the highest velocity of sphere impact for damage to initiate. Starphire{reg_sign} soda-lime silicate glass was second best, then Resistan{trademark}-G1 glass ceramic, and then BOROFLOAT{reg_sign} borosilicate glass. (2) Glass-ceramic Resistan{trademark}-L also required the largest force to initiate ring crack from quasi-static indentation. That ranking was followed, in descending order, by Starphire{reg_sign} soda-lime silicate glass, Resistan{trademark}-G1 glass ceramic, and BOROFLOAT{reg_sign} borosilicate glass. (3) Spheres with a lower elastic modulus require less force to initiate fracture in Resistan{trademark}-G1 from quasi-static spherical indentation. This indicates that friction is affecting ring crack initiation in Resistan{trademark}-G1. Friction also affected ring crack initiation in Starphire{reg_sign} soda-lime silicate and BOROFLOAT{reg_sign} borosilicate glasses. Among these three materials, friction was the most pronounced (largest slope in the RCIF-elastic modulus graph) in the Starphire{reg_sign} and least pronounced in the BOROFLOAT{reg_sign}. The reason for this is not understood, but differences in deformation behavior under high contact stresses could be a cause or contributor to this. (4) The force necessary to initiate contact-induced fracture is higher under dynamic conditions than it is under quasi-static conditions in Resistan{trademark}-L and Resistan{trademark}-G1 glass ceramics. This is a trend observed too in Starphire{reg_sign} and BOROFLOAT{reg_sign}. (5) There is a subtle indication there was intra-tile differences in spherical indentation-induced ring crack initiation forces. This is not a material property nor is it exclusive to glass-ceramic Resistan{trademark}-G1 glass ceramic, rather, it is a statistical mechanical response to an accumulated history of processing and handling of that specific tile.

  6. Note: Simultaneous measurement of transverse speed and axial velocity from a single optical beam

    SciTech Connect (OSTI)

    Moro, Erik A.; Briggs, Matthew E. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2013-01-15T23:59:59.000Z

    A method is introduced for simultaneously measuring transverse speed and axial velocity using a single optical beam and a standard photon Doppler velocimetry (PDV) sensing architecture. This result is of particular interest given the recent, widespread use of PDV and the fact that optical velocimetry has thus far been limited to measuring motion in one dimension per probe. Further, this result demonstrates that both axial velocity data and transverse speed data (at least qualitative) may be obtained entirely through signal analysis; not requiring hardware modification. This result is immediately relevant to analyses of existing PDV data and to future efforts in high-speed optical velocimetry.

  7. Natural discharge after pulse and cooperative electrodes to enhance droplet velocity in digital microfluidics

    SciTech Connect (OSTI)

    Chen, Tianlan; Dong, Cheng; Gao, Jie; Jia, Yanwei; Mak, Pui-In, E-mail: pimak@umac.mo; Vai, Mang-I; Martins, Rui P. [State Key Laboratory of Analog and Mixed-Signal VLSI and FST-ECE, University of Macau, Macao (China)] [State Key Laboratory of Analog and Mixed-Signal VLSI and FST-ECE, University of Macau, Macao (China)

    2014-04-15T23:59:59.000Z

    Digital Microfluidics (DMF) is a promising technology for biological/chemical micro-reactions due to its distinct droplet manageability via electronic automation, but the limited velocity of droplet transportation has hindered DMF from utilization in high throughput applications. In this paper, by adaptively fitting the actuation voltages to the dynamic motions of droplet movement under real-time feedback monitoring, two control-engaged electrode-driving techniques: Natural Discharge after Pulse (NDAP) and Cooperative Electrodes (CE) are proposed. They together lead to, for the first time, enhanced droplet velocity with lower root mean square voltage value.

  8. On the velocity-strengthening behavior of dry friction

    E-Print Network [OSTI]

    Yohai Bar-Sinai; Robert Spatschek; Efim A. Brener; Eran Bouchbinder

    2014-04-15T23:59:59.000Z

    The onset of frictional instabilities, e.g. earthquakes nucleation, is intimately related to velocity-weakening friction, in which the frictional resistance of interfaces decreases with increasing slip velocity. While this frictional response has been studied extensively, less attention has been given to steady-state velocity-strengthening friction, in spite of its potential importance for various aspects of frictional phenomena such as the propagation speed of interfacial rupture fronts and the amount of stored energy released by them. In this note we suggest that a crossover from steady-state velocity-weakening friction at small slip velocities to steady-state velocity-strengthening friction at higher velocities might be a generic feature of dry friction. We further argue that while thermally activated rheology naturally gives rise to logarithmic steady-state velocity-strengthening friction, a crossover to stronger-than-logarithmic strengthening might take place at higher slip velocities, possibly accompanied by a change in the dominant dissipation mechanism. We sketch a few physical mechanisms that may account for the crossover to stronger-than-logarithmic steady-state velocity-strengthening and compile a rather extensive set of experimental data available in the literature, lending support to these ideas.

  9. TANGENTIAL VELOCITY OF THE DARK MATTER IN THE BULLET CLUSTER FROM PRECISE LENSED IMAGE REDSHIFTS

    SciTech Connect (OSTI)

    Molnar, Sandor M. [Leung Center for Cosmology and Particle Astrophysics, National Taiwan University, Taipei 10617, Taiwan (China); Broadhurst, Tom [Fisika Teorikoa, Zientzia eta Teknologia Fakultatea, Euskal Herriko Unibertsitatea UPV/EHU, 644 Posta Kutxatila, E-48080 Bilbao (Spain); Umetsu, Keiichi [Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 10617, Taiwan (China); Zitrin, Adi [Universitaet Heidelberg, Zentrum fuer Astronomie, Institut fuer Theoretische Astrophysik, Philosophenweg 12, D-69120 Heidelberg (Germany); Rephaeli, Yoel; Shimon, Meir, E-mail: sandor@phys.ntu.edu.tw [School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978 (Israel)

    2013-09-01T23:59:59.000Z

    We show that the fast-moving component of the ''Bullet Cluster'' (1E0657-56) can induce potentially resolvable redshift differences between multiply lensed images of background galaxies. This moving cluster effect, due to the tangential peculiar velocity of the lens, can be expressed as the scalar product of the lensing deflection angle with the tangential velocity of the mass components; the effect is maximal for clusters colliding in the plane of the sky with velocities boosted by their mutual gravity. The Bullet Cluster is likely to be the best candidate for the first measurement of this effect due to the large collision velocity and because the lensing deflection and the cluster fields can be calculated in advance. We derive the deflection field using multiply lensed background galaxies detected with the Hubble Space Telescope. The velocity field is modeled using self-consistent N-body/hydrodynamical simulations constrained by the observed X-ray and gravitational lensing features of this system. We predict that the triply lensed images of systems ''G'' and ''H'' straddling the critical curve of the bullet component will show the largest frequency shifts up to {approx}0.5 km s{sup -1}. These shifts are within the range of the Atacama Large Millimeter/Submillimeter Array for molecular emission, and are near the resolution limit of the new generation high-throughput optical-IR spectrographs. The detection of this effect measures the tangential motion of the subclusters directly, thereby clarifying the tension with {Lambda}CDM, which is inferred from the gas motion less directly. This method may be extended to smaller redshift differences using the Ly{alpha} forest toward QSOs lensed by more typical clusters of galaxies. More generally, the tangential component of the peculiar velocities of clusters derived by our method complements the radial component determined by the kinematic Sunyaev-Zel'dovich effect, providing a full three-dimensional description of velocities.

  10. NON-GAUSSIAN STATISTICS AND STELLAR ROTATIONAL VELOCITIES OF MAIN-SEQUENCE FIELD STARS

    SciTech Connect (OSTI)

    Carvalho, J. C.; Do Nascimento, J. D.; Silva, R.; De Medeiros, J. R. [Universidade Federal do Rio Grande do Norte, UFRN, Departamento de Fisica, C. P. 1641, Natal, RN 59072-970 (Brazil)

    2009-05-01T23:59:59.000Z

    In this Letter, we study the observed distributions of rotational velocity in a sample of more than 16,000 nearby F and G dwarf stars, magnitude complete, and presenting high-precision Vsin i measurements. We show that the velocity distributions cannot be fitted by a Maxwellian. In addition, an analysis based on both Tsallis and Kaniadakis power-law statistics is by far the most appropriate statistics and gives a very good fit. It is also shown that single and binary stars have similar rotational distributions. This is the first time, to our knowledge, that these two new statistics have been tested for the rotation of such a large sample of stars, pointing solidly to a solution of the puzzling problem of the function governing the distribution of stellar rotational velocity.

  11. TEMPLATE RR LYRAE H{alpha}, H{beta}, AND H{gamma} VELOCITY CURVES

    SciTech Connect (OSTI)

    Sesar, Branimir, E-mail: bsesar@astro.caltech.edu [Division of Physics, Mathematics, and Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States)

    2012-10-01T23:59:59.000Z

    We present template radial velocity curves of ab-type RR Lyrae stars constructed from high-precision measurements of H{alpha}, H{beta}, and H{gamma} lines. Amplitude correlations between the Balmer line velocity curves, Johnson V band, and Sloan Digital Sky Survey (SDSS) g- and r-band light curves are also derived. Compared to previous methods, these templates and derived correlations reduce the uncertainty in measured systemic (center-of-mass) velocities of RR Lyrae stars by up to 15 km s{sup -1}, and will be of particular interest to wide-area spectroscopic surveys such as the SDSS and LAMOST Experiment for Galactic Understanding and Exploration.

  12. Time-resolved particle velocity measurements at impact velocities of 10 km/s

    SciTech Connect (OSTI)

    Furnish, M.D.; Chhabildas, L.C.; Reinhart, W.D.

    1998-08-01T23:59:59.000Z

    Hypervelocity launch capabilities (9--16 km/s) with macroscopic plates have become available in recent years. It is now feasible to conduct instrumented plane-wave tests using this capability. Successfully conducting such tests requires a planar launch and impact at hypervelocities, appropriate triggering for recording systems, and time-resolved measurements of motion or stress at a particular point or set of points within the target or projectile during impact. The authors have conducted the first time-resolved wave-profile experiments using velocity interferometric techniques at impact velocities of 10 km/s. These measurements show that aluminum continues to exhibit normal release behavior to 161 GPa shock pressure, with complete loss of strength of the shocked state. These experiments have allowed a determination of shock-wave window transparency in conditions produced by a hypervelocity impact. In particular, lithium fluoride appears to lose transparency at a shock stress of 200 GPa; this appears to be the upper limit for conventional wave profile measurements using velocity interferometric techniques.

  13. Tracking granules at the Sun's surface and reconstructing velocity fields. II. Error analysis

    E-Print Network [OSTI]

    R. Tkaczuk; M. Rieutord; N. Meunier; T. Roudier

    2007-07-13T23:59:59.000Z

    The determination of horizontal velocity fields at the solar surface is crucial to understanding the dynamics and magnetism of the convection zone of the sun. These measurements can be done by tracking granules. Tracking granules from ground-based observations, however, suffers from the Earth's atmospheric turbulence, which induces image distortion. The focus of this paper is to evaluate the influence of this noise on the maps of velocity fields. We use the coherent structure tracking algorithm developed recently and apply it to two independent series of images that contain the same solar signal. We first show that a k-\\omega filtering of the times series of images is highly recommended as a pre-processing to decrease the noise, while, in contrast, using destretching should be avoided. We also demonstrate that the lifetime of granules has a strong influence on the error bars of velocities and that a threshold on the lifetime should be imposed to minimize errors. Finally, although solar flow patterns are easily recognizable and image quality is very good, it turns out that a time sampling of two images every 21 s is not frequent enough, since image distortion still pollutes velocity fields at a 30% level on the 2500 km scale, i.e. the scale on which granules start to behave like passive scalars. The coherent structure tracking algorithm is a useful tool for noise control on the measurement of surface horizontal solar velocity fields when at least two independent series are available.

  14. Velocity measurements in the near field of a diesel fuel injector by ultrafast imagery

    E-Print Network [OSTI]

    Sedarsky, David; Blaisot, Jean-Bernard; Rozé, Claude

    2013-01-01T23:59:59.000Z

    This paper examines the velocity profile of fuel issuing from a high-pressure single-orifice diesel injector. Velocities of liquid structures were determined from time-resolved ultrafast shadow images, formed by an amplified two-pulse laser source coupled to a double-frame camera. A statistical analysis of the data over many injection events was undertaken to map velocities related to spray formation near the nozzle outlet as a function of time after start of injection. These results reveal a strong asymmetry in the liquid profile of the test injector, with distinct fast and slow regions on opposite sides of the orifice. Differences of ~100 m/s can be observed between the 'fast' and 'slow' sides of the jet, resulting in different atomization conditions across the spray. On average, droplets are dispersed at a greater distance from the nozzle on the 'fast' side of the flow, and distinct macrostructure can be observed under the asymmetric velocity conditions. The changes in structural velocity and atomization b...

  15. Out-of-plane ultrasonic velocity measurement

    DOE Patents [OSTI]

    Hall, M.S.; Brodeur, P.H.; Jackson, T.G.

    1998-07-14T23:59:59.000Z

    A method for improving the accuracy of measuring the velocity and time of flight of ultrasonic signals through moving web-like materials such as paper, paperboard and the like, includes a pair of ultrasonic transducers disposed on opposing sides of a moving web-like material. In order to provide acoustical coupling between the transducers and the web-like material, the transducers are disposed in fluid-filled wheels. Errors due to variances in the wheel thicknesses about their circumference which can affect time of flight measurements and ultimately the mechanical property being tested are compensated by averaging the ultrasonic signals for a predetermined number of revolutions. The invention further includes a method for compensating for errors resulting from the digitization of the ultrasonic signals. More particularly, the invention includes a method for eliminating errors known as trigger jitter inherent with digitizing oscilloscopes used to digitize the signals for manipulation by a digital computer. In particular, rather than cross-correlate ultrasonic signals taken during different sample periods as is known in the art in order to determine the time of flight of the ultrasonic signal through the moving web, a pulse echo box is provided to enable cross-correlation of predetermined transmitted ultrasonic signals with predetermined reflected ultrasonic or echo signals during the sample period. By cross-correlating ultrasonic signals in the same sample period, the error associated with trigger jitter is eliminated. 20 figs.

  16. True Masses of Radial-Velocity Exoplanets

    E-Print Network [OSTI]

    Brown, Robert A

    2015-01-01T23:59:59.000Z

    We explore the science power of space telescopes used to estimate the true masses of known radial-velocity exoplanets by means of astrometry on direct images. We translate a desired mass accuracy (+/10% in our example) into a minimum goal for the signal-to-noise ratio, which implies a minimum exposure time. When the planet is near a node, the mass measurement becomes difficult if not impossible, because the apparent separation becomes decoupled from the inclination angle of the orbit. The combination of this nodal effect with considerations of solar and anti-solar pointing restrictions, photometric and obscurational completeness, and image blurring due to orbital motion, severely limits the observing opportunities, often to only brief intervals in a five-year mission. We compare the science power of four missions, two with external star shades, EXO-S and WFIRST-S, and two with internal coronagraphs, EXO-C and WFIRST-C. The star shades out-perform the coronagraph in this science program by about a factor of th...

  17. Out-of-plane ultrasonic velocity measurement

    DOE Patents [OSTI]

    Hall, Maclin S. (Marietta, GA); Brodeur, Pierre H. (Smyrna, GA); Jackson, Theodore G. (Atlanta, GA)

    1998-01-01T23:59:59.000Z

    A method for improving the accuracy of measuring the velocity and time of flight of ultrasonic signals through moving web-like materials such as paper, paperboard and the like, includes a pair of ultrasonic transducers disposed on opposing sides of a moving web-like material. In order to provide acoustical coupling between the transducers and the web-like material, the transducers are disposed in fluid-filled wheels. Errors due to variances in the wheel thicknesses about their circumference which can affect time of flight measurements and ultimately the mechanical property being tested are compensated by averaging the ultrasonic signals for a predetermined number of revolutions. The invention further includes a method for compensating for errors resulting from the digitization of the ultrasonic signals. More particularly, the invention includes a method for eliminating errors known as trigger jitter inherent with digitizing oscilloscopes used to digitize the signals for manipulation by a digital computer. In particular, rather than cross-correlate ultrasonic signals taken during different sample periods as is known in the art in order to determine the time of flight of the ultrasonic signal through the moving web, a pulse echo box is provided to enable cross-correlation of predetermined transmitted ultrasonic signals with predetermined reflected ultrasonic or echo signals during the sample period. By cross-correlating ultrasonic signals in the same sample period, the error associated with trigger jitter is eliminated.

  18. Limiting velocities as running parameters and superluminal neutrinos

    E-Print Network [OSTI]

    Mohamed M. Anber; John F. Donoghue

    2011-10-01T23:59:59.000Z

    In the context of theories where particles can have different limiting velocities, we review the running of particle speeds towards a common limiting velocity at low energy. Motivated by the recent OPERA experimental results, we describe a model where the neutrinos would deviate from the common velocity by more than do other particles in the theory, because their running is slower due to weaker interactions.

  19. The thin section rock physics: Modeling and measurement of seismic wave velocity on the slice of carbonates

    SciTech Connect (OSTI)

    Wardaya, P. D., E-mail: pongga.wardaya@utp.edu.my; Noh, K. A. B. M., E-mail: pongga.wardaya@utp.edu.my; Yusoff, W. I. B. W., E-mail: pongga.wardaya@utp.edu.my [Petroleum Geosciences Department, Universiti Teknologi PETRONAS, Tronoh, Perak, 31750 (Malaysia); Ridha, S. [Petroleum Engineering Department, Universiti Teknologi PETRONAS, Tronoh, Perak, 31750 (Malaysia); Nurhandoko, B. E. B. [Wave Inversion and Subsurface Fluid Imaging Research Laboratory (WISFIR), Dept. of Physics, Institute of Technology Bandung, Bandung, Indonesia and Rock Fluid Imaging Lab, Bandung (Indonesia)

    2014-09-25T23:59:59.000Z

    This paper discusses a new approach for investigating the seismic wave velocity of rock, specifically carbonates, as affected by their pore structures. While the conventional routine of seismic velocity measurement highly depends on the extensive laboratory experiment, the proposed approach utilizes the digital rock physics view which lies on the numerical experiment. Thus, instead of using core sample, we use the thin section image of carbonate rock to measure the effective seismic wave velocity when travelling on it. In the numerical experiment, thin section images act as the medium on which wave propagation will be simulated. For the modeling, an advanced technique based on artificial neural network was employed for building the velocity and density profile, replacing image's RGB pixel value with the seismic velocity and density of each rock constituent. Then, ultrasonic wave was simulated to propagate in the thin section image by using finite difference time domain method, based on assumption of an acoustic-isotropic medium. Effective velocities were drawn from the recorded signal and being compared to the velocity modeling from Wyllie time average model and Kuster-Toksoz rock physics model. To perform the modeling, image analysis routines were undertaken for quantifying the pore aspect ratio that is assumed to represent the rocks pore structure. In addition, porosity and mineral fraction required for velocity modeling were also quantified by using integrated neural network and image analysis technique. It was found that the Kuster-Toksoz gives the closer prediction to the measured velocity as compared to the Wyllie time average model. We also conclude that Wyllie time average that does not incorporate the pore structure parameter deviates significantly for samples having more than 40% porosity. Utilizing this approach we found a good agreement between numerical experiment and theoretically derived rock physics model for estimating the effective seismic wave velocity of rock.

  20. acoustic wave velocity: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the offered analytical method the determinant relation for a phase velocities of elastic waves for an arbitrary propagation directions in a piezoelectric crystal are received. The...

  1. aggregate sound velocities: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    an acoustic loop filter Physics Websites Summary: observation of negative group velocity propagation of sound waves through an asymmetric loop filterSound beyond the speed of...

  2. Crust and Upper Mantle P Wave Velocity Structure Beneath Valles...

    Open Energy Info (EERE)

    Crust and Upper Mantle P Wave Velocity Structure Beneath Valles Caldera, New Mexico- Results from the Jemez Teleseismic Tomography Experiment Jump to: navigation, search OpenEI...

  3. adiabatic burning velocity: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Sciences Websites Summary: burning velocities under conditions for which the net heat loss of the flame is zero. Very similar values, France 2 IFP Energies nouvelles, 1 et...

  4. Modified definition of group velocity and electromagnetic energy conservation equation

    E-Print Network [OSTI]

    Changbiao Wang

    2015-01-19T23:59:59.000Z

    The classical definition of group velocity has two flaws: (a) the group velocity can be greater than the phase velocity in a non-dispersive, lossless, non-conducting, anisotropic uniform medium; (b) the definition is not consistent with the principle of relativity for a plane wave in a moving isotropic uniform medium. To remove the flaws, a modified definition is proposed. A criterion is set up to identify the justification of group velocity definition. A "superluminal power flow" is constructed to show that the electromagnetic energy conservation equation cannot uniquely define the power flow if the principle of Fermat is not taken into account.

  5. USING MICRO-SEISMICITY AND SEISMIC VELOCITIES TO MAP SUBSURFACE...

    Open Energy Info (EERE)

    GEOTHERMAL FIELD, CALIFORNIA Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Proceedings: USING MICRO-SEISMICITY AND SEISMIC VELOCITIES TO MAP...

  6. Using Micro-Seismicity and Seismic Velocities to Map Subsurface...

    Open Energy Info (EERE)

    Geothermal Field California Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Paper: Using Micro-Seismicity and Seismic Velocities to Map Subsurface...

  7. A novel photonic Doppler velocimetry for transverse velocity measurement

    SciTech Connect (OSTI)

    Chen Guanghua; Wang Detian; Liu Jun; Meng Jianhua; Liu Shouxian; Yang Qingguo [Institute of Fluid Physics, CAEP, P.O. Box 919-109, Mianyang, Sichuan 621900 (China)

    2013-01-15T23:59:59.000Z

    A fiber interferometry for transverse velocity measurement has been developed. This diagnostic is similar to photonic Doppler velocimetry in the way in which laser propagates and couples. The interferometer mainly consists of a fiber coupler, an emitting probe, and two receiving probes. A pair of scattered laser beams mix in the coupler and generates fringes with frequency proportional to transverse velocity. Measurement of transverse velocity is independent of longitudinal velocity. The feasibility of the technique has been verified by rotating wheel experiment and shock loading experiment.

  8. Determination of Surface Exciton Energies by Velocity Resolved...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Exciton Energies by Velocity Resolved Atomic Desorption. Abstract: We have developed a new method for determining surface exciton band energies in alkali halides based on...

  9. anisotropic electron velocity: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    A simple model reflecting Cerveny, Vlastislav 8 Anisotropic velocity distributions in 3D dissipative optical lattices Quantum Physics (arXiv) Summary: We present a direct...

  10. air stream velocities: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the early universe, substantial relative "stream" velocities between the gas and dark matter arise due to radiation pressure and persist after recombination. To asses the impact...

  11. Nonlinear peculiar-velocity analysis and PCA

    SciTech Connect (OSTI)

    Dekel, A. [and others

    2001-02-20T23:59:59.000Z

    We allow for nonlinear effects in the likelihood analysis of peculiar velocities, and obtain {approximately}35%-lower values for the cosmological density parameter and for the amplitude of mass-density fluctuations. The power spectrum in the linear regime is assumed to be of the flat {Lambda}CDM model (h = 0:65, n = 1) with only {Omega}{sub m} free. Since the likelihood is driven by the nonlinear regime, we break the power spectrum at k{sub b} {approximately} 0.2 (h{sup {minus}1} Mpc){sup {minus}1} and fit a two-parameter power-law at k > k{sub b} . This allows for an unbiased fit in the linear regime. Tests using improved mock catalogs demonstrate a reduced bias and a better fit. We find for the Mark III and SFI data {Omega}{sub m} = 0.35 {+-} 0.09 with {sigma}{sub 8}{Omega}P{sub m}{sup 0.6} = 0.55 {+-} 0.10 (90% errors). When allowing deviations from {Lambda}CDM, we find an indication for a wiggle in the power spectrum in the form of an excess near k {approximately} 0.05 and a deficiency at k {approximately} 0.1 (h{sup {minus}1} Mpc){sup {minus}1}--a cold flow which may be related to a feature indicated from redshift surveys and the second peak in the CMB anisotropy. A {chi}{sup 2} test applied to principal modes demonstrates that the nonlinear procedure improves the goodness of fit. The Principal Component Analysis (PCA) helps identifying spatial features of the data and fine-tuning the theoretical and error models. We address the potential for optimal data compression using PCA.

  12. The Pathfinder Testbed: Exploring Techniques for Achieving Precision Radial Velocities in the Near-Infrared

    E-Print Network [OSTI]

    Ramsey, Larry; Redman, Stephen; Bender, Chad; Roy, Arpita; Zonak, Stephanie; Sigurdsson, Steinn; Wolszczan, Alex

    2010-01-01T23:59:59.000Z

    The Penn State Pathfinder is a prototype warm fiber-fed Echelle spectrograph with a Hawaii-1 NIR detector that has already demonstrated 7-10 m/s radial velocity precision on integrated sunlight. The Pathfinder testbed was initially setup for the Gemini PRVS design study to enable a systematic exploration of the challenges of achieving high radial velocity precision in the near-infrared, as well as to test possible solutions to these calibration challenges. The current version of the Pathfinder has an R3 echelle grating, and delivers a resolution of R~50,000 in the Y, J or H bands of the spectrum. We will discuss the on sky-performance of the Pathfinder during an engineering test run at the Hobby Eberly Telescope as well the results of velocity observations of M dwarfs. We will also discuss the unique calibration techniques we have explored, like Uranium-Neon hollow cathode lamps, notch filter, and modal noise mitigation to enable high precision radial velocity observation in the NIR. The Pathfinder is a proto...

  13. A shortened version of this paper appeared in IEEE Computer, October 1994. 1 HighPressure Steam Engines and Computer Software \\Lambda

    E-Print Network [OSTI]

    Leveson, Nancy

    A shortened version of this paper appeared in IEEE Computer, October 1994. 1 High­Pressure Steam the same mistakes. In particular, parallels exist between the early develop­ ment of high­pressure steam A History of the Growth of the Steam Engine (1883) Hero of Alexandria, who lived around 60 AD, con­ ducted

  14. Lowell, Massachusetts, Preserves Historic Home Through Energy...

    Energy Savers [EERE]

    include a high-velocity, small-duct HVAC system, updated storm windows, and attic insulation. These upgrades will reduce humidity in order to preserve the artwork displayed, and...

  15. DOE Tour of Zero: The School Street Homes by StreetScape Development...

    Energy Savers [EERE]

    fresh air system all use the same small-diameter (2-inch) high-velocity duct system and central air handler, which is located in the basement and zone controlled with temperature...

  16. Hydrocarbon saturation determination using acoustic velocities obtained through casing

    DOE Patents [OSTI]

    Moos, Daniel (Houston, TX)

    2010-03-09T23:59:59.000Z

    Compressional and shear velocities of earth formations are measured through casing. The determined compressional and shear velocities are used in a two component mixing model to provides improved quantitative values for the solid, the dry frame, and the pore compressibility. These are used in determination of hydrocarbon saturation.

  17. Measurements of Laminar Flame Velocity for Components of Natural Gas

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    flame velocity of components of natural gas, methane, ethane, propane, and nbutane as well as of binary% by volume (1). The laminar flame velocities of methane/air, ethane/air, and propane/air mixtures have on a plenum chamber with the radial temperature distribution measurement made by a series of thermocouples

  18. A laser Doppler method for noninvasive measurement of flow velocity

    SciTech Connect (OSTI)

    Biggs, G.L.

    1986-11-25T23:59:59.000Z

    Laser Doppler velocimetry is a powerful optical technique for noninvasively obtaining experimental flow-velocity data. This paper describes the principle of operation and various optical configurations of the laser Doppler velocimeter. As a sample application, we describe an experimental apparatus for measuring the velocity flow field around a cylinder, and give our experimental results.

  19. Field-effect transistor having a superlattice channel and high carrier velocities at high applied fields

    DOE Patents [OSTI]

    Chaffin, R.J.; Dawson, L.R.; Fritz, I.J.; Osbourn, G.C.; Zipperian, T.E.

    1987-06-08T23:59:59.000Z

    A field effect transistor comprises a semiconductor having a source, a drain, a channel and a gate in operational relationship. The semiconductor is a strained layer superlattice comprising alternating quantum well and barrier layers, the quantum well layers and barrier layers being selected from the group of layer pairs consisting of InGaAs/AlGaAs, InAs/InAlGaAs, and InAs/InAlAsP. The layer thicknesses of the quantum well and barrier layers are sufficiently thin that the alternating layers constitute a superlattice which has a superlattice conduction band energy level structure in k-vector space. The layer thicknesses of the quantum well layers are selected to provide a superlattice L/sub 2D/-valley which has a shape which is substantially more two-dimensional than that of said bulk L-valley. 2 figs.

  20. A comparison of light and velocity variations in Semiregular variables

    E-Print Network [OSTI]

    T. Lebzelter; L. L. Kiss; K. H. Hinkle

    2000-09-21T23:59:59.000Z

    NIR velocity variations are compared with simultaneous visual light curves for a sample of late-type semiregular variables (SRV). Precise radial velocity measurements are also presented for the SRV V450 Aql. Our aim is to investigate the nature of the irregular light changes found in these variables. Light and velocity variations are correlated in all stars of our sample. Based on these results we discuss several possibilities to explain the observed behavior. We find that pulsation is responsible for large amplitude variations. In a recent paper Lebzelter (1999) invoked large convective cells to understand observed velocity variations. This possibility is discussed with respect to the observed correlation between light and velocity changes. In the light of these results we investigate the origin of the semiregular variations.

  1. Precision Measuring of Velocities via the Relativistic Doppler Effect

    E-Print Network [OSTI]

    Leonid M. Ozernoy

    1997-12-26T23:59:59.000Z

    Just as the ordinary Doppler effect serves as a tool to measure radial velocities of celestial objects, so can the relativistic Doppler effect be implemented to measure a combination of radial and transverse velocities by using recent improvements in observing techniques. A key element that makes a further use of this combination feasible is the periodicity in changes of the orbital velocity direction for the source. Two cases are considered: (i) a binary star; and (ii) a solitary star with the planetary companion. It is shown that, in case (i), several precision Doppler measurements employing the gas absorption cell technique would determine both the total orbital velocity and the inclination angle of the binary orbit disentangled from the peculiar velocity of the system. The necessary condition for that is the measured, at least with a modest precision, proper motion and distance to the system.

  2. Precision Measuring of Velocities via the Relativistic Doppler Effect

    E-Print Network [OSTI]

    Ozernoy, L M

    1997-01-01T23:59:59.000Z

    Just as the ordinary Doppler effect serves as a tool to measure radial velocities of celestial objects, so can the relativistic Doppler effect be implemented to measure a combination of radial and transverse velocities by using recent improvements in observing techniques. A key element that makes a further use of this combination feasible is the periodicity in changes of the orbital velocity direction for the source. Two cases are considered: (i) a binary star; and (ii) a solitary star with the planetary companion. It is shown that, in case (i), several precision Doppler measurements employing the gas absorption cell technique would determine both the total orbital velocity and the inclination angle of the binary orbit disentangled from the peculiar velocity of the system. The necessary condition for that is the measured, at least with a modest precision, proper motion and distance to the system.

  3. Discrimination of porosity and fluid saturation using seismic velocity analysis

    DOE Patents [OSTI]

    Berryman, James G. (Danville, CA)

    2001-01-01T23:59:59.000Z

    The method of the invention is employed for determining the state of saturation in a subterranean formation using only seismic velocity measurements (e.g., shear and compressional wave velocity data). Seismic velocity data collected from a region of the formation of like solid material properties can provide relatively accurate partial saturation data derived from a well-defined triangle plotted in a (.rho./.mu., .lambda./.mu.)-plane. When the seismic velocity data are collected over a large region of a formation having both like and unlike materials, the method first distinguishes the like materials by initially plotting the seismic velocity data in a (.rho./.lambda., .mu./.lambda.)-plane to determine regions of the formation having like solid material properties and porosity.

  4. Effects of crossflow velocity and transmembrane pressure on microfiltration of oil-in-water emulsions

    E-Print Network [OSTI]

    Darvishzadeh, Tohid

    2012-01-01T23:59:59.000Z

    This study addresses the issue of oil removal from water using hydrophilic porous membranes. The effective separation of oil-in-water dispersions involves high flux of water through the membrane and, at the same time, high rejection rate of the oil phase. The effects of transmembrane pressure and crossflow velocity on rejection of oil droplets and thin oil films by pores of different cross-section are investigated numerically by solving the Navier-Stokes equation. We found that in the absence of crossflow, the critical transmembrane pressure, which is required for the oil droplet entry into a circular pore of a given surface hydrophilicity, agrees well with analytical predictions based on the Young-Laplace equation. With increasing crossflow velocity, the shape of the oil droplet is strongly deformed near the pore entrance and the critical pressure of permeation increases. We determined numerically the phase diagram for the droplet rejection, permeation, and breakup depending of the transmembrane pressure and...

  5. Stellar Velocity Dispersion of the Leo A Dwarf Galaxy

    E-Print Network [OSTI]

    Warren R. Brown; Margaret J. Geller; Scott J. Kenyon; Michael J. Kurtz

    2007-05-08T23:59:59.000Z

    We measure the first stellar velocity dispersion of the Leo A dwarf galaxy, \\sigma = 9.3 +- 1.3 km/s. We derive the velocity dispersion from the radial velocities of ten young B supergiants and two HII regions in the central region of Leo A. We estimate a projected mass of 8 +- 2.7 x10^7 solar masses within a radius of 2 arcmin, and a mass to light ratio of at least 20 +- 6 M_sun/L_sun. These results imply Leo A is at least ~80% dark matter by mass.

  6. Two-stream instability with time-dependent drift velocity

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Qin, Hong [PPPL; Davidson, Ronald C. [PPPL

    2014-01-01T23:59:59.000Z

    The classical two-stream instability driven by a constant relative drift velocity between two plasma components is extended to the case with time-dependent drift velocity. A solution method is developed to rigorously define and calculate the instability growth rate for linear perturbations relative to the time-dependent unperturbed two-stream motions. Stability diagrams for the oscillating two-stream instability are presented over a large region of parameter space. It is shown that the growth rate for the classical two-stream instability can be significantly reduced by adding an oscillatory component to the relative drift velocity.

  7. Measuring Oscillatory Velocity Fields Due to Swimming Algae

    E-Print Network [OSTI]

    Guasto, Jeffrey S; Gollub, J P

    2010-01-01T23:59:59.000Z

    In this fluid dynamics video, we present the first time-resolved measurements of the oscillatory velocity field induced by swimming unicellular microorganisms. Confinement of the green alga C. reinhardtii in stabilized thin liquid films allows simultaneous tracking of cells and tracer particles. The measured velocity field reveals complex time-dependent flow structures, and scales inversely with distance. The instantaneous mechanical power generated by the cells is measured from the velocity fields and peaks at 15 fW. The dissipation per cycle is more than four times what steady swimming would require.

  8. Two-stream instability with time-dependent drift velocity

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Qin, Hong; Davidson, Ronald C.

    2014-06-01T23:59:59.000Z

    The classical two-stream instability driven by a constant relative drift velocity between two plasma components is extended to the case with time-dependent drift velocity. A solution method is developed to rigorously define and calculate the instability growth rate for linear perturbations relative to the time-dependent unperturbed two-stream motions. Stability diagrams for the oscillating two-stream instability are presented over a large region of parameter space. It is shown that the growth rate for the classical two-stream instability can be significantly reduced by adding an oscillatory component to the relative drift velocity.

  9. Building America Top Innovations 2013 Profile Â… Buried and Encapsulated Ducts

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't Your Destiny: Theof Energy Future ofHydronic HeatingManagement of High-R Walls |FurringThis

  10. Probing dark energy models with extreme pairwise velocities of galaxy clusters from the DEUS-FUR simulations

    E-Print Network [OSTI]

    Bouillot, Vincent R; Corasaniti, Pier-Stefano; Rasera, Yann

    2015-01-01T23:59:59.000Z

    Observations of colliding galaxy clusters with high relative velocity probe the tail of the halo pairwise velocity distribution with the potential of providing a powerful test of cosmology. As an example it has been argued that the discovery of the Bullet Cluster challenges standard $\\Lambda$CDM model predictions. Halo catalogs from N-body simulations have been used to estimate the probability of Bullet-like clusters. However, due to simulation volume effects previous studies had to rely on a Gaussian extrapolation of the pairwise velocity distribution to high velocities. Here, we perform a detail analysis using the halo catalogs from the Dark Energy Universe Simulation Full Universe Runs (DEUS-FUR), which enables us to resolve the high-velocity tail of the distribution and study its dependence on the halo mass definition, redshift and cosmology. Building upon these results we estimate the probability of Bullet-like systems in the framework of Extreme Value Statistics. We show that the tail of extreme pairwis...

  11. Tracer airflow measurement system (TRAMS)

    DOE Patents [OSTI]

    Wang, Duo (Albany, CA)

    2007-04-24T23:59:59.000Z

    A method and apparatus for measuring fluid flow in a duct is disclosed. The invention uses a novel high velocity tracer injector system, an optional insertable folding mixing fan for homogenizing the tracer within the duct bulk fluid flow, and a perforated hose sampling system. A preferred embodiment uses CO.sub.2 as a tracer gas for measuring air flow in commercial and/or residential ducts. In extant commercial buildings, ducts not readily accessible by hanging ceilings may be drilled with readily plugged small diameter holes to allow for injection, optional mixing where desired using a novel insertable foldable mixing fan, and sampling hose.

  12. Multipole seismoelectric logging while drilling (LWD) for acoustic velocity measurements

    E-Print Network [OSTI]

    Zhu, Zhenya

    2012-01-01T23:59:59.000Z

    In seismoelectric well logging, an acoustic wave propagates along a borehole and induces electrical signals along the borehole wall. The apparent velocities of these seismoelectric signals are equal to the formation ...

  13. P wave velocity variations in the Coso region, California, derived...

    Open Energy Info (EERE)

    times Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: P wave velocity variations in the Coso region, California, derived from local earthquake...

  14. LOW VELOCITY SHPERE IMPACT OF SODA LIME SILICATE GLASS

    SciTech Connect (OSTI)

    Morrissey, Timothy G [ORNL; Fox, Ethan E [ORNL; Wereszczak, Andrew A [ORNL; Vuono, Daniel J [ORNL

    2012-01-01T23:59:59.000Z

    This report summarizes TARDEC-sponsored work at Oak Ridge National Laboratory (ORNL) during the FY11 involving low velocity ( 30 m/s or 65 mph) ball impact testing of Starphire soda lime silicate glass. The intent was to better understand low velocity impact response in the Starphire for sphere densities that bracketed that of rock. Five sphere materials were used: borosilicate glass, soda-lime silicate glass, steel, silicon nitride, and alumina. A gas gun was fabricated to produce controlled velocity delivery of the spheres against Starphire tile targets. Minimum impact velocities to initiate fracture in the Starphire were measured and interpreted in context to the kinetic energy of impact and the elastic property mismatch between the any of the five sphere-Starphire-target combinations.

  15. air velocity distribution: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Page Topic Index 1 Carbon isotope evidence for the latitudinal distribution and wind speed dependence of the air-sea gas transfer velocity University of California eScholarship...

  16. Superluminal Velocity of Photons in a Gravitational Background

    E-Print Network [OSTI]

    I. B. Khriplovich

    1994-11-20T23:59:59.000Z

    The influence of radiative corrections on the photon propagation in a gravitational background is investigated without the low-frequency approximation $\\omega \\ll m$. The conclusion is made in this way that the velocity of light can exceed unity.

  17. artery peak velocity: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    The time series analysis of Doppler velocity maps show enhanced power in the sunspot umbra at higher frequencies and in the penumbra at lower frequencies. We find that the peak...

  18. Seismic Velocity And Attenuation Structure Of The Geysers Geothermal...

    Open Energy Info (EERE)

    issue at this field is the distribution of fluid in the matrix of the reservoir rock. In this paper, we interpret seismic compressional-wave velocity and quality quotient...

  19. Effective velocities in fractured media: a numerical study using the ...

    E-Print Network [OSTI]

    2002-03-18T23:59:59.000Z

    theories that predict the effective P- and S-wave velocities in fractured materials in ... can be treated only by numerical techniques because analyt- ... apply the rotated staggered grid (Saenger, Gold and Shapiro ..... (r ? 0:2) and for SH-

  20. WIYN open cluster study. LIX. Radial velocity membership of the evolved population of the old open cluster NGC 6791

    SciTech Connect (OSTI)

    Tofflemire, Benjamin M.; Gosnell, Natalie M.; Mathieu, Robert D. [Department of Astronomy, University of Wisconsin-Madison, 475 North Charter Street, Madison, WI 53706 (United States); Platais, Imants, E-mail: tofflemi@astro.wisc.edu, E-mail: imants@pha.jhu.edu [Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, MD 21218 (United States)

    2014-10-01T23:59:59.000Z

    The open cluster NGC 6791 has been the focus of much recent study due to its intriguing combination of old age and high metallicity (?8 Gyr, [Fe/H] = +0.30), as well as its location within the Kepler field. As part of the WIYN Open Cluster Study, we present precise (? = 0.38 km s{sup –1}) radial velocities for proper motion candidate members of NGC 6791 from Platais et al. Our survey, extending down to g' ? 16.8, is comprised of the evolved cluster population, including blue stragglers, giants, and horizontal branch stars. Of the 280 proper-motion-selected stars above our magnitude limit, 93% have at least one radial velocity measurement and 79% have three measurements over the course of at least 200 days, sufficient for secure radial-velocity-determined membership of non-velocity-variable stars. The Platais et al. proper motion catalog includes 12 anomalous horizontal branch candidates blueward of the red clump, of which we find only 4 to be cluster members. Three fall slightly blueward of the red clump and the fourth is consistent with being a blue straggler. The cleaned color-magnitude diagram shows a richly populated red giant branch and a blue straggler population. Half of the blue stragglers are in binaries. From our radial velocity measurement distribution, we find the cluster's radial velocity dispersion to be ? {sub c} = 0.62 ± 0.10 km s{sup –1}. This corresponds to a dynamical mass of ?4600 M {sub ?}.

  1. Estimating propagation velocity through a surface acoustic wave sensor

    SciTech Connect (OSTI)

    Xu, Wenyuan (Oakdale, MN); Huizinga, John S. (Dellwood, MN)

    2010-03-16T23:59:59.000Z

    Techniques are described for estimating the propagation velocity through a surface acoustic wave sensor. In particular, techniques which measure and exploit a proper segment of phase frequency response of the surface acoustic wave sensor are described for use as a basis of bacterial detection by the sensor. As described, use of velocity estimation based on a proper segment of phase frequency response has advantages over conventional techniques that use phase shift as the basis for detection.

  2. Velocity of sound in solid methane near melting temperatures

    E-Print Network [OSTI]

    Whitehead, John Martin

    1968-01-01T23:59:59.000Z

    VELOCITY OF SOUND IN SOLID METHANE NEAR MELTING TEMPERATURES A Thesis By JOHN MARTIN WHITEHEAD Submitted to the Graduate College of the Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE May... 1968 Ma)or Sub)ect: Physics VELOCITY OF SOVND IN SOLID METHANE NEAR MELTING TEMPERATURES A Thesis By JOHN MARTIN WHITEHEAD Approved as to style and content by& (Chairman of Committee) (Head of Departsmnt) (Mem er (Member) May 1968...

  3. Study of Air Ingress Across the Duct During the Accident Conditions

    SciTech Connect (OSTI)

    Hassan, Yassin

    2013-05-06T23:59:59.000Z

    The goal of this project is to study the fundamental physical phenoena associated with air ingress in very high temperature reactors (VHTRs). Air ingress may occur due to a nupture of primary piping and a subsequent breach in the primary pressure boundary in helium-cooled and graphite-moderated VHTRs. Significant air ingress is a concern because it introduces potential to expose the fuel, graphite support rods, and core to a risk of severe graphite oxidation. Two of the most probable air ingress scenarios involve rupture of a control rod or fuel access standpipe, and rupture in the main coolant pipe on the lower part of the reactor pressure vessel. Therefor, establishing a fundamental understanding of air ingress phenomena is critical in order to rationally evaluate safety of existing VHTRs and develop new designs that mimimize these risks. But despite this importance, progress toward development these predictive capabilities has been slowed by the complex nature of the underlaying phenomena. The combination of interdiffusion among multiple species, molecular diffusion, natural convection, and complex geometries, as well as the multiple chemical reactions involved, impose significant roadblocks to both modeling and experiment design. The project team will employ a coordinated experimental and computational effort that will help gain a deeper understanding of multiphased air ingress phenomena. THis project will enhance advanced modeling and simulation methods, enabling calculation of nuclear power plant transients and accident scenarios with a high degree of confidence. The following are the project tasks: Perform particle image velocimetry measurement of multiphase air ingresses Perform computational fluid dynamics analysis of air ingress phenomena

  4. Seismic velocity inversion by differential semblance optimization

    SciTech Connect (OSTI)

    Gockenbach, M.; Symes, W.; Tapia, R.

    1994-12-31T23:59:59.000Z

    Differential Semblance Optimization (DSO) is a novel way of approaching certain inverse problems that arise in exploration seismology. The standard method of formulating these inverse problems -- Output Least-Squares (OLS) -- leads to a highly nonconvex objective function and therefore to a global optimization problem. The OLS problem can be rewritten as a partially linear least-squares problem with linear constraints, with the DSO objective function derived from the quadratic penalty function for this problem. It is shown that, because of the nature of the operators in this problem, the penalty function leads to a globalization procedure: for suitably small values of the penalty parameter, the global minimum of the DSO objective function can be found using local optimization techniques. There is then a path of minimizers, parameterized by the penalty constant, leading to the solution of the OLS problem.

  5. The concentration-velocity dispersion relation in galaxy groups

    E-Print Network [OSTI]

    Andreas Faltenbacher; William G. Mathews

    2007-06-08T23:59:59.000Z

    Based on results from cold dark matter N-body simulations we develop a dynamical model for the evolution of subhaloes within host haloes of galaxy groups. Only subhaloes more massive than 5 times 10^8 M_{sol} at the time of accretion are examined because they are massive enough to possibly host luminous galaxies. As they orbit within a growing host potential the subhaloes are subject to tidal stripping and dynamical friction. We consider groups of equal mass (M_{vir} = 3.9 times 10^{13} M_{sol}) at redshift z=0 but with different concentrations associated with different formation times. We investigate the variation of subhaloe (or satellite galaxy) velocity dispersion with host concentration and/or formation time. In agreement with the Jeans equation the velocity dispersion of subhaloes increases with the host concentration. Between concentrations ~5 and ~20 the subhaloe velocity dispersions increase by ~25 per cent. By applying a simplified tidal disruption criterion, i.e. rejection of all subhaloes with a tidal truncation radius below 3 kpc at z=0, the central velocity dispersion of 'surviving' subhaloes increases substantially for all concentrations. The enhanced central velocity dispersion among surviving subhaloes is caused by a lack of slow tangential motions. Additionally, we present a fitting formula for the velocity anisotropy parameter \\beta(r) which does not depend on concentration if the group-centric distances are scaled by r_s, the characteristic radius of the NFW-profile.

  6. Microstructure and Property Evolution in Advanced Cladding and Duct Materials Under Long-Term and Elevated Temperature Irradiation: Modeling and Experimental Investigation

    SciTech Connect (OSTI)

    Wirth, Brian; Morgan, Dane; Kaoumi, Djamel; Motta, Arthur

    2013-12-01T23:59:59.000Z

    The in-service degradation of reactor core materials is related to underlying changes in the irradiated microstructure. During reactor operation, structural components and cladding experience displacement of atoms by collisions with neutrons at temperatures at which the radiation-induced defects are mobile, leading to microstructure evolution under irradiation that can degrade material properties. At the doses and temperatures relevant to fast reactor operation, the microstructure evolves by dislocation loop formation and growth, microchemistry changes due to radiation-induced segregation, radiation-induced precipitation, destabilization of the existing precipitate structure, and in some cases, void formation and growth. These processes do not occur independently; rather, their evolution is highly interlinked. Radiationinduced segregation of Cr and existing chromium carbide coverage in irradiated alloy T91 track each other closely. The radiation-induced precipitation of Ni-Si precipitates and RIS of Ni and Si in alloys T91 and HCM12A are likely related. Neither the evolution of these processes nor their coupling is understood under the conditions required for materials performance in fast reactors (temperature range 300-600°C and doses beyond 200 dpa). Further, predictive modeling is not yet possible as models for microstructure evolution must be developed along with experiments to characterize these key processes and provide tools for extrapolation. To extend the range of operation of nuclear fuel cladding and structural materials in advanced nuclear energy and transmutation systems to that required for the fast reactor, the irradiation-induced evolution of the microstructure, microchemistry, and the associated mechanical properties at relevant temperatures and doses must be understood. Predictive modeling relies on an understanding of the physical processes and also on the development of microstructure and microchemical models to describe their evolution under irradiation. This project will focus on modeling microstructural and microchemical evolution of irradiated alloys by performing detailed modeling of such microstructure evolution processes coupled with well-designed in situ experiments that can provide validation and benchmarking to the computer codes. The broad scientific and technical objectives of this proposal are to evaluate the microstructure and microchemical evolution in advanced ferritic/martensitic and oxide dispersion strengthened (ODS) alloys for cladding and duct reactor materials under long-term and elevated temperature irradiation, leading to improved ability to model structural materials performance and lifetime. Specifically, we propose four research thrusts, namely Thrust 1: Identify the formation mechanism and evolution for dislocation loops with Burgers vector of a<100> and determine whether the defect microstructure (predominately dislocation loop/dislocation density) saturates at high dose. Thrust 2: Identify whether a threshold irradiation temperature or dose exists for the nucleation of growing voids that mark the beginning of irradiation-induced swelling, and begin to probe the limits of thermal stability of the tempered Martensitic structure under irradiation. Thrust 3: Evaluate the stability of nanometer sized Y- Ti-O based oxide dispersion strengthened (ODS) particles at high fluence/temperature. Thrust 4: Evaluate the extent to which precipitates form and/or dissolve as a function of irradiation temperature and dose, and how these changes are driven by radiation induced segregation and microchemical evolutions and determined by the initial microstructure.

  7. A photoelectron velocity map imaging spectrometer for experiments combining synchrotron and laser radiations

    SciTech Connect (OSTI)

    O'Keeffe, P.; Bolognesi, P.; Coreno, M.; Avaldi, L. [CNR-IMIP, Area della Ricerca di Roma 1, Monterotondo Scalo (Italy); Moise, A.; Richter, R.; Cautero, G.; Stebel, L.; Sergo, R. [Sincrotrone Trieste SCpA, Area Science Park, I-34149 Basovizza (Trieste) (Italy); Pravica, L. [The University of Western Australia, 35 Stirling Hwy, Crawley, Western Australia (Australia); Ovcharenko, Y. [Institute of Electron Physics, 88017 Uzhgorod (Ukraine)

    2011-03-15T23:59:59.000Z

    A velocity map imaging/ion time-of-flight spectrometer designed specifically for pump-probe experiments combining synchrotron and laser radiations is described. The in-house built delay line detector can be used in two modes: the high spatial resolution mode and the coincidence mode. In the high spatial resolution mode a kinetic energy resolution of 6% has been achieved. The coincidence mode can be used to improve signal-to-noise ratio for the pump-probe experiments either by using a gate to count electrons only when the laser is present or by recording coincidences with the ion formed in the ionization process.

  8. The velocity gradient in the pseudo-photosphere of the peculiar supergiant HD101584

    E-Print Network [OSTI]

    Eric J. Bakker

    1995-10-23T23:59:59.000Z

    In this paper preliminary results are presented based on a study of the low and high resolution ultraviolet spectrum of the peculiar supergiant (post-AGB star) HD101584. By a comparison of the low resolution spectrum (1200-3200ang) with standard stars, the star is classified as an A7I, indicating an effective temperature of 8150 K, where literature quotes spectral type F0I. The Doppler shift of the FeII absorption lines in the high resolution spectrum (2500-3000ang) show a relation with the line optical depth. This suggests an expanding accelerating wind, c.q. pseudo-photosphere. The relation is extended by a factor 10^5 in optical depth by using available data from optical HeI and NI lines. The relation suggests that the radial heliocentric velocity of the star is at least 54.5km/s. From the Halpha line a velocity of 96km/s is measured for the terminal velocity of the wind.

  9. The velocity gradient in the pseudo-photosphere of the peculiar supergiant HD101584

    E-Print Network [OSTI]

    Bakker, E J

    1995-01-01T23:59:59.000Z

    In this paper preliminary results are presented based on a study of the low and high resolution ultraviolet spectrum of the peculiar supergiant (post-AGB star) HD101584. By a comparison of the low resolution spectrum (1200-3200ang) with standard stars, the star is classified as an A7I, indicating an effective temperature of 8150 K, where literature quotes spectral type F0I. The Doppler shift of the FeII absorption lines in the high resolution spectrum (2500-3000ang) show a relation with the line optical depth. This suggests an expanding accelerating wind, c.q. pseudo-photosphere. The relation is extended by a factor 10^5 in optical depth by using available data from optical HeI and NI lines. The relation suggests that the radial heliocentric velocity of the star is at least 54.5km/s. From the Halpha line a velocity of 96km/s is measured for the terminal velocity of the wind.

  10. Engineering development of coal-fired high performance power systems, Phase II and Phase III. Quarter progress report, April 1, 1996--June 30, 1996

    SciTech Connect (OSTI)

    NONE

    1996-11-01T23:59:59.000Z

    Work is presented on the development of a coal-fired high performance power generation system by the year 2000. This report describes the design of the air heater, duct heater, system controls, slag viscosity, and design of a quench zone.

  11. DEPOSITION VELOCITY ESTIMATION WITH THE GENII V2 SOFTWARE

    SciTech Connect (OSTI)

    Hutchins, H.

    2012-04-23T23:59:59.000Z

    In 2010, the Department of Energy (DOE) Chief of Nuclear Safety and Office of Health, Safety and Security (HSS), with the support of industry experts in atmospheric sciences and accident dose consequences analysis, performed detailed analyses of the basis for the dry deposition velocity (DV) values used in the MACCS2 computer code. As a result of these analyses, DOE concluded that the historically used default DV values of 1 centimeter/second (cm/s) for unfiltered/unmitigated releases and 0.1 cm/s for filtered/mitigated releases may not be reasonably conservative for all DOE sites and accident scenarios. HSS recently issued Safety Bulletin 2011-02, Accident Analysis Parameter Update, recommending the use of the newly developed default DV, 0.1 cm/s for an unmitigated/unfiltered release. Alternatively site specific DV values can be developed using GENII version 2 (GENII v2) computer code. Key input parameters for calculating DV values include surface roughness, maximum wind speed for calm, particle size, particle density and meteorological data (wind speed and stability class). This paper will include reasonably conservative inputs, and a truncated parametric study. In lieu of the highly-conservative recommended DV value (0.1cm/s) for unmitigated/unfiltered release, GENII v2 has been used to justify estimated 95th percentile DV values. Also presented here are atmospheric dilution factors ({chi}/Q values) calculated with the MACCS2 code using the DV values form GENII v2, {chi}/Q values calculated directly with GENII v2, and a discussion of these results compare with one another. This paper will give an overview of the process of calculating DV with GENII v2 including a discussion of the sensitivity of input parameters.

  12. Propagation velocities of gas rings in collisional ring galaxies

    E-Print Network [OSTI]

    E. I. Vorobyov; D. Bizyaev

    2003-01-27T23:59:59.000Z

    The propagation velocity of the first gas ring in collisional ring galaxies, i.e. the velocity at which the maximum in the radial gas density profile propagates radially in the galactic disk, is usually inferred from the radial expansion velocity of gas in the first ring. Our numerical hydrodynamics modeling of ring galaxy formation however shows that the maximum radial expansion velocity of gas in the first ring ($v_{gas}$) is invariably below the propagation velocity of the first gas ring itself ($v_{ring}$). Modeling of the Cartwheel galaxy indicates that the outer ring is currently propagating at $v_{ring} \\approx$ 100 km/s, while the maximum radial expansion velocity of gas in the outer ring is currently $v_{gas} \\approx$ 65 km/s. Modeling of the radial B-V/V-K color gradients of the Cartwheel ring galaxy also indicates that the outer ring is propagating at $v_{ring} \\ge $ 90 km/s. We show that a combined effect of inclination, finite thickness, and warping of the Cartwheel's disk might be responsible for the lack of angular difference in the peak positions found for the azimuthally averaged $H\\alpha$, K and B surface brightness profiles of the Cartwheel's outer ring. Indeed, the radial $H\\alpha$ surface brightness profiles obtained along the Cartwheel's major axis, where effects of inclination and finite thickness are minimized, do peak exterior to those at K- and B-bands. The angular difference in peak positions implies $v_{ring}$ = 110 km/s, which is in agreement with the model predictions. We briefly discuss the utility of radio continuum emission and spectral line equivalent widths for determining the propagation velocity of gas rings in collisional ring galaxies.

  13. Extensional wave attenuation and velocity in partially-saturated sand in the sonic frequency range

    SciTech Connect (OSTI)

    Liu, Z.; Rector, J.W.; Nihei, K.T.; Tomutsa, L.; Myer, L.R.; Nakagawa, S.

    2002-06-17T23:59:59.000Z

    Extensional wave attenuation and velocity measurements on a high permeability Monterey sand were performed over a range of gas saturations for imbibition and degassing conditions. These measurements were conducted using extensional wave pulse propagation and resonance over a 1 - 9 kHz frequency range for a hydrostatic confining pressure of 8.3 MPa. Analysis of the extensional wave data and the corresponding X-ray CT images of the gas saturation show strong attenuation resulting from the presence of the gas (QE dropped from 300 for the dry sand to 30 for the partially-saturated sand), with larger attenuation at a given saturation resulting from heterogeneous gas distributions. The extensional wave velocities are in agreement with Gassmann theory for the test with near-homogeneous gas saturation and with a patchy saturation model for the test with heterogeneous gas saturation. These results show that partially-saturated sands under moderate confining pressure can produce strong intrinsic attenuation for extensional waves.

  14. Analytic solutions for seismic travel time and ray path geometry through simple velocity models.

    SciTech Connect (OSTI)

    Ballard, Sanford

    2007-12-01T23:59:59.000Z

    The geometry of ray paths through realistic Earth models can be extremely complex due to the vertical and lateral heterogeneity of the velocity distribution within the models. Calculation of high fidelity ray paths and travel times through these models generally involves sophisticated algorithms that require significant assumptions and approximations. To test such algorithms it is desirable to have available analytic solutions for the geometry and travel time of rays through simpler velocity distributions against which the more complex algorithms can be compared. Also, in situations where computational performance requirements prohibit implementation of full 3D algorithms, it may be necessary to accept the accuracy limitations of analytic solutions in order to compute solutions that satisfy those requirements. Analytic solutions are described for the geometry and travel time of infinite frequency rays through radially symmetric 1D Earth models characterized by an inner sphere where the velocity distribution is given by the function V (r) = A-Br{sup 2}, optionally surrounded by some number of spherical shells of constant velocity. The mathematical basis of the calculations is described, sample calculations are presented, and results are compared to the Taup Toolkit of Crotwell et al. (1999). These solutions are useful for evaluating the fidelity of sophisticated 3D travel time calculators and in situations where performance requirements preclude the use of more computationally intensive calculators. It should be noted that most of the solutions presented are only quasi-analytic. Exact, closed form equations are derived but computation of solutions to specific problems generally require application of numerical integration or root finding techniques, which, while approximations, can be calculated to very high accuracy. Tolerances are set in the numerical algorithms such that computed travel time accuracies are better than 1 microsecond.

  15. Ducts Sealing Using Injected Spray Sealant, Raleigh, North Carolina (Fact Sheet), Building America Case Study: Technology Solutions for New and Existing Homes, Building Technologies Office (BTO)

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directed offOCHCO OverviewAttachments461-93Do-It-YourselfDucts Sealing Using Injected Spray Sealant Raleigh,

  16. Exceptional Ground Accelerations and Velocities Caused by Earthquakes

    SciTech Connect (OSTI)

    Anderson, John

    2008-01-17T23:59:59.000Z

    This project aims to understand the characteristics of the free-field strong-motion records that have yielded the 100 largest peak accelerations and the 100 largest peak velocities recorded to date. The peak is defined as the maximum magnitude of the acceleration or velocity vector during the strong shaking. This compilation includes 35 records with peak acceleration greater than gravity, and 41 records with peak velocities greater than 100 cm/s. The results represent an estimated 150,000 instrument-years of strong-motion recordings. The mean horizontal acceleration or velocity, as used for the NGA ground motion models, is typically 0.76 times the magnitude of this vector peak. Accelerations in the top 100 come from earthquakes as small as magnitude 5, while velocities in the top 100 all come from earthquakes with magnitude 6 or larger. Records are dominated by crustal earthquakes with thrust, oblique-thrust, or strike-slip mechanisms. Normal faulting mechanisms in crustal earthquakes constitute under 5% of the records in the databases searched, and an even smaller percentage of the exceptional records. All NEHRP site categories have contributed exceptional records, in proportions similar to the extent that they are represented in the larger database.

  17. Control of group velocity by phase-changing collisions

    SciTech Connect (OSTI)

    Goren, C.; Rosenbluh, M. [Department of Physics, Bar-Ilan University, Ramat Gan 52900 (Israel); Wilson-Gordon, A.D.; Friedmann, H. [Department of Chemistry, Bar-Ilan University, Ramat Gan 52900 (Israel)

    2005-08-15T23:59:59.000Z

    We discuss the influence of phase-changing collisions on the group velocities in Doppler-broadened, cycling, degenerate two-level systems where F{sub e}=F{sub g}+1 and F{sub g}>0, interacting with pump and probe lasers, that exhibit electromagnetically induced absorption (EIA). Two model systems are considered: the N system where the pump and probe are polarized perpendicularly, and EIA is due to transfer of coherence (TOC), and the double two-level system (TLS) where both lasers have the same polarization, and EIA is due to transfer of population (TOP). For the case of Doppler-broadened EIA TOC, which occurs at low pump intensity, there is a switch from positive to negative dispersion and group velocity, as the rate of phase-changing collisions is increased. For the case of EIA TOP at low pump intensity, the dispersion and group velocity remain negative even when the collision rate is increased. Pressure-induced narrowing, accompanied by an increase in the magnitude of the negative dispersion and a decrease in the magnitude of the negative group velocity, occurs in both EIA TOC and EIA TOP, at low pump intensity. When the pump intensity is increased, a switch from negative to positive dispersion and group velocity, with increasing collision rate, also occurs in the double TLS system. However, the effect is far smaller than in the case of the N system at low pump intensity.

  18. The application of boundary layer removal to a 90 degree bend used as a flow turing device

    E-Print Network [OSTI]

    Smith, Edward Harrison

    1959-01-01T23:59:59.000Z

    Attached to Nozzle; High Velocity 30 Efficiency vs Percent Flow Removed; Bend. Attached to Nozzle; Low Velocity 31 Efficiency vs Percent Flow Removed; Bend Attached to 1. 5 Foot Duct; High Velocity 32 Efficiency vs Percent Flow Removed; Bend Attached... to 1. 5 Foot Duct; Low Velocity 33 Static Pressure vs Angle of Bend 37 38 40 41 A C K N 0 W L E D G E M E N T S The author wishes to express his appreciation to Profes- sor Alfred E. Cronk for his advice and patience; and to his wife, Annabelle...

  19. SUBSTRUCTURE IN BULK VELOCITIES OF MILKY WAY DISK STARS

    SciTech Connect (OSTI)

    Carlin, Jeffrey L.; DeLaunay, James; Newberg, Heidi Jo; Gole, Daniel; Grabowski, Kathleen [Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, Troy, NY 12180 (United States)] [Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, Troy, NY 12180 (United States); Deng, Licai; Liu, Chao; Luo, A-Li; Zhang, Haotong; Zhao, Gang; Zhao, Yongheng [Key Lab for Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)] [Key Lab for Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China); Jin, Ge [University of Science and Technology of China, Hefei 230026 (China)] [University of Science and Technology of China, Hefei 230026 (China); Liu, Xiaowei; Yuan, Haibo, E-mail: carlij@rpi.edu [Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871 (China)] [Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871 (China)

    2013-11-01T23:59:59.000Z

    We find that Galactic disk stars near the anticenter exhibit velocity asymmetries in both the Galactocentric radial and vertical components across the midplane as well as azimuthally. These findings are based on Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) spectroscopic velocities for a sample of ?400, 000 F-type stars, combined with proper motions from the PPMXL catalog for which we have derived corrections to the zero points based in part on spectroscopically discovered galaxies and QSOs from LAMOST. In the region within 2 kpc outside the Sun's radius and ±2 kpc from the Galactic midplane, we show that stars above the plane exhibit net outward radial motions with downward vertical velocities, while stars below the plane have roughly the opposite behavior. We discuss this in the context of other recent findings, and conclude that we are likely seeing the signature of vertical disturbances to the disk due to an external perturbation.

  20. The Velocity Field of Quasar Broad Emission Line Gas

    E-Print Network [OSTI]

    Brian Punsly

    2007-01-25T23:59:59.000Z

    In this Letter, the broad emission line (BEL) profiles of superluminal quasars with apparent jet velocities, $\\beta_{a}>10$, (ultraluminal QSOs, or ULQSOs hereafter) are studied as a diagnostic of the velocity field of the BEL emitting gas in quasars. The ULQSOs are useful because they satisfy a very strict kinematical constraint, their parsec scale jets must be propagating within $12^{\\circ}$ of the line of sight. We know the orientation of these objects with great certainty. The large BEL FWHM, $\\sim 3,000 \\mathrm{km/s} - 6,000 \\mathrm{km/s}$, in ULQSOs tend to indicate that the BEL gas has a larger component of axial velocity (either random or in a wind) along the jet direction than previously thought.

  1. Measurement of Poloidal Velocity on the National Spherical Torus Experiment

    SciTech Connect (OSTI)

    Ronald E. Bell and Russell Feder

    2010-06-04T23:59:59.000Z

    A diagnostic suite has been developed to measure impurity poloidal flow using charge exchange recombination spectroscopy on the National Spherical Torus Experiment. Toroidal and poloidal viewing systems measure all quantities required to determine the radial electric field. Two sets of up/down symmetric poloidal views are used to measure both active emission in the plane of the neutral heating beams and background emission in a radial plane away from the neutral beams. Differential velocity measurements isolate the line-integrated poloidal velocity from apparent flows due to the energy-dependent chargeexchange cross section. Six f/1.8 spectrometers measure 276 spectra to obtain 75 active and 63 background channels every 10 ms. Local measurements from a similar midplane toroidal viewing system are mapped into two dimensions to allow the inversion of poloidal line-integrated measurements to obtain local poloidal velocity profiles. Radial resolution after inversion is 0.6-1.8 cm from the plasma edge to the center.

  2. Planar velocity analysis of diesel spray shadow images

    E-Print Network [OSTI]

    Sedarsky, David; Blaisot, J-B; Rozé, C

    2012-01-01T23:59:59.000Z

    The focus of this work is to demonstrate how spatially resolved image information from diesel fuel injection events can be obtained using a forward-scatter imaging geometry, and used to calculate the velocities of liquid structures on the periphery of the spray. In order to obtain accurate velocities directly from individual diesel spray structures, those features need to be spatially resolved in the measurement. The distributed structures measured in a direct shadowgraphy arrangement cannot be reliably analyzed for this kind of velocity information. However, by utilizing an intense collimated light source and adding imaging optics which modify the signal collection, spatially resolved optical information can be retrieved from spray edge regions within a chosen object plane. This work discusses a set of measurements where a diesel spray is illuminated in rapid succession by two ultrafast laser pulses generated by a mode-locked Ti-Sapphire oscillator seeding a matched pair of regenerative amplifiers. Light fro...

  3. St. Stephen powerhouse tailrace velocity measurement. Final report

    SciTech Connect (OSTI)

    Fagerburg, T.L.

    1986-09-01T23:59:59.000Z

    Tests were conducted to provide a prototype evaluation of the operating conditions of the project and to evaluate the adequacy of the repairs and remedial work performed in the channel downstream of the tailrace. Prototype measurements were made to define the relative magnitudes of velocities and the surface flow patterns in the channel downstream of the tailrace and the displacement, if any, of the stone protection material resulting from various turbine operations and tailwater conditions. Results of the data collection included determination of (a) velocity distribution at various ranges across the channel; (b) velocity profiles at the toe of the slope and at the observed location of highest velocity; and (c) unusual surface flow patterns that are produced by different combinations of turbine operations. Recommendations for start-up and shut-down procedures for the turbine operations that would produce the most acceptable. The depth soundings revealed that the stone protection material was quite stable (District surveys reveal that no appreciable displacement has occurred during the subsequent months of operation of the powerhouse.) The flow velocities were found to concentrate along the right side of the channel as a result of uneven flow distribution from the draft tube bays and the asymmetrical geometry along the left side of the tailrace. Return flows were observed and found to concentrate along the left side of the channel except when all three turbines were operating. Operating recommendations for the turbines are made based on tailwater conditions, length of time of nonoperation of the powerhouse, and the velocity data obtained from the tests.

  4. Fermi velocity renormalization and dynamical gap generation in graphene

    E-Print Network [OSTI]

    C. Popovici; C. S. Fischer; L. von Smekal

    2015-01-12T23:59:59.000Z

    We study the renormalization of the Fermi velocity by the long-range Coulomb interactions between the charge carriers in the Dirac-cone approximation for the effective low-energy description of the electronic excitations in graphene at half filling. Solving the coupled system of Dyson-Schwinger equations for the dressing functions in the corresponding fermion propagator with various approximations for the particle-hole polarization we observe that Fermi velocity renormalization effects generally lead to a considerable increase of the critical coupling for dynamical gap generation and charge-density wave formation at the semimetal-insulator transition.

  5. SGP and TWP (Manus) Ice Cloud Vertical Velocities

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Kalesse, Heike

    Daily netcdf-files of ice-cloud dynamics observed at the ARM sites at SGP (Jan1997-Dec2010) and Manus (Jul1999-Dec2010). The files include variables at different time resolution (10s, 20min, 1hr). Profiles of radar reflectivity factor (dbz), Doppler velocity (vel) as well as retrieved vertical air motion (V_air) and reflectivity-weighted particle terminal fall velocity (V_ter) are given at 10s, 20min and 1hr resolution. Retrieved V_air and V_ter follow radar notation, so positive values indicate downward motion. Lower level clouds are removed, however a multi-layer flag is included.

  6. Edge Turbulence Velocity Changes with Lithium Coating on NSTX

    SciTech Connect (OSTI)

    Cao, A.; Zweben, S. J.; Stotler, D. P.; Bell, M.; Diallo, A.; Kaye, S. M.; LeBlanc, B.

    2012-08-10T23:59:59.000Z

    Lithium coating improves energy confinement and eliminates edge localized modes in NSTX, but the mechanism of this improvement is not yet well understood. We used the gas-puff-imaging (GPI) diagnostic on NSTX to measure the changes in edge turbulence which occurred during a scan with variable lithium wall coating, in order to help understand the reason for the confinement improvement with lithium. There was a small increase in the edge turbulence poloidal velocity and a decrease in the poloidal velocity fluctuation level with increased lithium. The possible effect of varying edge neutral density on turbulence damping was evaluated for these cases in NSTX. __________________________________________________

  7. ELECTROSTATIC MODE ASSOCIATED WITH PINCH VELOCITY IN RFPS

    SciTech Connect (OSTI)

    DELZANNO, GIAN LUCA [Los Alamos National Laboratory; FINN, JOHN M. [Los Alamos National Laboratory; CHACON, LUIS [Los Alamos National Laboratory

    2007-02-08T23:59:59.000Z

    The existence of a new electrostatic instability is shown for RFP (reversed field pinch) equilibria. This mode arises due to the non-zero equilibrium radial flow (pinch flow). In RFP simulations with no-stress boundary conditions on the tangential velocity at the radial wall, this electrostatic mode is unstable and dominates the nonlinear dynamics, even in the presence of the MHD modes typically responsible for the reversal of the axial magnetic field at edge. Nonlinearly, this mode leads to two beams moving azimuthally towards each other, which eventually collide. The electrostatic mode can be controlled by using Dirichlet (no-slip) boundary conditions on the azimuthal velocity at the radial wall.

  8. Extreme Value Analysis of Tidal Stream Velocity Perturbations

    SciTech Connect (OSTI)

    Harding, Samuel; Thomson, Jim; Polagye, Brian; Richmond, Marshall C.; Durgesh, Vibhav; Bryden, Ian

    2011-04-26T23:59:59.000Z

    This paper presents a statistical extreme value analysis of maximum velocity perturbations from the mean flow speed in a tidal stream. This study was performed using tidal velocity data measured using both an Acoustic Doppler Velocimeter (ADV) and an Acoustic Doppler Current Profiler (ADCP) at the same location which allows for direct comparison of predictions. The extreme value analysis implements of a Peak-Over-Threshold method to explore the effect of perturbation length and time scale on the magnitude of a 50-year perturbation.

  9. Velocity determination of the very shallow lunar crust

    E-Print Network [OSTI]

    Yen, Tzuhua Edward

    1979-01-01T23:59:59.000Z

    , 1972 and 1974 ) for the Apollo 16 and 17 landing sites, respectively. A deep layer of dust on the moon may provide a very good seismic-wave transmission channel. In order to investigate the seismic properties of such a medium, Gold and Soter (1970...) at the Apollo 14 and 16 landing sites has been determined to be a self-compacting powder layer overlying a homogeneous layer. The velocity function of the powder layer is given by V(z)=V (z/z ) , where V =340+20 m/sec is a reference 1/6 0 0 0 velocity at a...

  10. Source shape determination with directional fragment-fragment velocity correlations

    E-Print Network [OSTI]

    Lefèvre, A; Auger, G; Begemann-Blaich, M L; Bellaize, N; Bittiger, R; Bocage, F; Borderie, B; Bougault, R; Bouriquet, B; Charvet, J L; Chbihi, A; Dayras, R; Durand, D; Frankland, J D; Galíchet, E; Gourio, D; Guinet, D; Hudan, S; Lautesse, P; Lavaud, F; Legrain, R; López, O; Lukasik, J; Lynen, U; Müller, W F J; Nalpas, L; Orth, H; Plagnol, E; Rosato, E; Saija, A; Sfienti, C; Tamain, B; Trautmann, W; Trzcinski, A; Turzó, K; Vient, E; Vigilante, M; Volant, C; Zwieglinski, B

    2008-01-01T23:59:59.000Z

    Correlation functions, constructed from directional projections of the relative velocities of fragments, are used to determine the shape of the breakup volume in coordinate space. For central collisions of 129Xe + natSn at 50 MeV per nucleon incident energy, measured with the 4pi multi-detector INDRA at GSI, a prolate shape aligned along the beam direction with an axis ratio of 1:0.7 is deduced. The sensitivity of the method is discussed in comparison with conventional fragment-fragment velocity correlations.

  11. Effect of the q-nonextensive electron velocity distribution on a magnetized plasma sheath

    SciTech Connect (OSTI)

    Safa, N. Navab, E-mail: n-navabsafa@sbu.ac.ir; Ghomi, H.; Niknam, A. R. [Laser and Plasma Research Institute, Shahid Beheshti University, Tehran 1983963113 (Iran, Islamic Republic of)

    2014-08-15T23:59:59.000Z

    In this work, a sheath model has been developed to investigate the effect of the q-nonextensive electron velocity distribution on the different characteristics of a magnetized plasma. By using Segdeev potential method, a modified Bohm criterion for a magnetized plasma with the nonextensive electron velocity distribution is derived. The sheath model is then used to analyze numerically the sheath structure under different q, the parameter quantifying the nonextensivity degree of the system. The results show that as the q-parameter decreases, the floating potential becomes more negative. The sheath length increases at the lower values of the q-parameter due to the increase in the electron population at the high-energy tail of the distribution function. As q-parameter decreases, the effective temperature of the electrons increases which results in a more extended plasma sheath. The ion velocity and density profiles for the different nonextensivity degrees of the system reflect the gyro-motion of the ions in the presence of the magnetic field. Furthermore, the results coincide with those given by the Maxwellian electron distribution function, when q tends to 1.

  12. A Terminal Velocity on the Landscape: Particle Production near Extra Species Loci in Higher Dimensions

    E-Print Network [OSTI]

    Diana Battefeld; Thorsten Battefeld

    2011-02-10T23:59:59.000Z

    We investigate particle production near extra species loci (ESL) in a higher dimensional field space and derive a speed limit in moduli space at weak coupling. This terminal velocity is set by the characteristic ESL-separation and the coupling of the extra degrees of freedom to the moduli, but it is independent of the moduli's potential if the dimensionality of the field space is considerably larger than the dimensionality of the loci, D >> d. Once the terminal velocity is approached, particles are produced at a plethora of nearby ESLs, preventing a further increase in speed via their backreaction. It is possible to drive inflation at the terminal velocity, providing a generalization of trapped inflation with attractive features: we find that more than sixty e-folds of inflation for sub-Planckian excursions in field space are possible if ESLs are ubiquitous, without fine tuning of initial conditions and less tuned potentials. We construct a simple, observationally viable model with a slightly red scalar power-spectrum and suppressed gravitational waves; we comment on the presence of additional observational signatures originating from IR-cascading and individual massive particles. We also show that moduli-trapping at an ESL is suppressed for D >> d, hindering dynamical selection of high-symmetry vacua on the landscape based on this mechanism.

  13. Isolating signatures of major cloud-cloud collisions using position-velocity diagrams

    E-Print Network [OSTI]

    Haworth, T J; Fukui, Y; Torii, K; Dale, J E; Shima, K; Takahira, K; Habe, A; Hasegawa, K

    2015-01-01T23:59:59.000Z

    Collisions between giant molecular clouds are a potential mechanism for triggering the formation of massive stars, or even super star clusters. The trouble is identifying this process observationally and distinguishing it from other mechanisms. We produce synthetic position-velocity diagrams from models of: cloud-cloud collisions, non-interacting clouds along the line of sight, clouds with internal radiative feedback and a more complex cloud evolving in a galactic disc, to try and identify unique signatures of collision. We find that a broad bridge feature connecting two intensity peaks, spatially correlated but separated in velocity, is a signature of a high velocity cloud-cloud collision. We show that the broad bridge feature is resilient to the effects of radiative feedback, at least to around 2.5Myr after the formation of the first massive (ionising) star. However for a head on 10km/s collision we find that this will only be observable from 20-30 per cent of viewing angles. Such broad-bridge features have...

  14. Duct and cladding alloy

    DOE Patents [OSTI]

    Korenko, Michael K. (Rockville, MD)

    1983-01-01T23:59:59.000Z

    An austenitic alloy having good thermal stability and resistance to sodium corrosion at 700.degree. C. consists essentially of 35-45% nickel 7.5-14% chromium 0.8-3.2% molybdenum 0.3-1.0% silicon 0.2-1.0% manganese 0-0.1% zirconium 2.0-3.5% titanium 1.0-2.0% aluminum 0.02-0.1% carbon 0-0.01% boron and the balance iron.

  15. The Light Velocity Casimir Effect Does the Velocity of Light Increase when Propagating Between the Casimir Plates?

    E-Print Network [OSTI]

    Ostoma, T; Ostoma, Tom; Trushyk, Mike

    1999-01-01T23:59:59.000Z

    We propose experiments that might be set up to detect the increase in the velocity of light in a vacuum in the laboratory frame for photons travelling between (and perpendicular to) the Casimir plates in a vacuum. The Casimir plates are two closely spaced, conductive plates, where an attractive force is observed to exist between the plates called the 'Casimir Force'. We propose that the velocity of light in a vacuum increases when propagating between two transparent Casimir Plates. We call this effect the 'Light Velocity Casimir Effect' or LVC effect. The LVC effect happens because the vacuum energy density in between the plates is lower than that outside the Casimir plates. The conductive plates disallow certain frequencies of electrically charged virtual particles to exist inside the plates, thus lowering the inside vacuum particle density, compared to the density outside the plates. The reduced (electrically charged) virtual particle density results in fewer photon scattering events inside the plates, whic...

  16. Continued Evaluation of the Pulse-Echo Ultrasonic Instrument for Critical Velocity Determination during Hanford Tank Waste Transfer Operations - 12518

    SciTech Connect (OSTI)

    Denslow, Kayte M.; Bontha, Jagannadha R.; Adkins, Harold E.; Jenks, Jeromy W.J.; Burns, Carolyn A.; Schonewill, Philip P.; Hopkins, Derek F. [Pacific Northwest National Laboratory, Richland, Washington 99354 (United States); Thien, Michael G.; Wooley, Theodore A. [Washington River Protection Solutions, Richland, Washington 99354 (United States)

    2012-07-01T23:59:59.000Z

    The delivery of Hanford double-shell tank waste to the Hanford Tank Waste Treatment and Immobilization Plant (WTP) will be governed by specific Waste Acceptance Criteria that are identified in ICD 19 - Interface Control Document for Waste Feed. Waste must be certified as acceptable before it can be delivered to the WTP. The fluid transfer velocity at which solid particulate deposition occurs in waste slurry transport piping (critical velocity) is a key waste parameter that must be accurately characterized to determine if the waste is acceptable for transfer to the WTP. In 2010 Washington River Protection Solutions and the Pacific Northwest National Laboratory began evaluating the ultrasonic PulseEcho instrument to accurately identify critical velocities in a horizontal slurry transport pipeline for slurries containing particles with a mean particle diameter of >50 micrometers. In 2011 the PulseEcho instrument was further evaluated to identify critical velocities for slurries containing fast-settling, high-density particles with a mean particle diameter of <15 micrometers. This two-year evaluation has demonstrated the ability of the ultrasonic PulseEcho instrument to detect the onset of critical velocity for a broad range of physical and rheological slurry properties that are likely encountered during the waste feed transfer operations between the Hanford tank farms and the WTP. (authors)

  17. Investigation of plasma velocity field solar flare footpoints

    E-Print Network [OSTI]

    Mrozek, Tomasz

    of Wroclaw NCN Grant 2011/01/M/ST9/06096 #12;The Solar Flare - observations #12;chromosphere corona photosphere The Solar Flare - cartoon - conversion of magnetic energy into other forms - transport of energyInvestigation of plasma velocity field in solar flare footpoints from RHESSI observations T. Mrozek

  18. Scale-dependent seismic velocity in heterogeneous media

    SciTech Connect (OSTI)

    Mukerji, T.; Mavko, G.; Mujica, D. [Stanford Univ., CA (United States)] [Stanford Univ., CA (United States); Lucet, N. [IFP, Rueil-Malmaison (France)] [IFP, Rueil-Malmaison (France)

    1995-07-01T23:59:59.000Z

    The measurable traveltime of seismic events propagating in heterogeneous media depend on the geologic scale, the seismic wavelength, and the propagation distance. In general, the velocity inferred from arrival times is slower when the wavelength is longer than the scale of heterogeneity and faster when the wavelength is shorter. For normal incidence propagation in stratified media, this is the difference between averaging elastic compliance sin the long wavelength limit. In two and three dimensions there is also the path effect. Shorter wavelengths tend to find faster paths, thus biasing the traveltimes to lower values. In the shorter wavelength limit, the slowness inferred from the average traveltime is smaller than the mean slowness of the medium. When the propagation distance is much larger than the scale of the heterogeneity, the path effect causes the velocity increase from long to short wavelengths to be much larger in two dimensions than in one dimension, and even larger in three dimensions. The amount of velocity dispersion can be understood theoretically, but there is some discrepancy between theory and experiment as to what ratio of wavelength to heterogeneity scale separates the long and short wavelength limits. The scale-dependent traveltime implies that a measured velocity depends not just on rock properties, but also on the scale of the measurement relative to he scale of the geology.

  19. Velocity Autocorrelation Functions and Diffusion of Dusty Plasma

    SciTech Connect (OSTI)

    Ramazanov, T. S.; Dzhumagulova, K. N.; Daniyarov, T. T.; Dosbolayev, M. K.; Jumabekov, A. N. [IETP, al-Farabi Kazakh National University, 96a, Tole bi St., Almaty, 050012 (Kazakhstan)

    2008-09-07T23:59:59.000Z

    The velocity autocorrelation functions and square displacements were calculated on the basis of experimental data obtained on experimental setup with dc discharge. Computer simulation of the system of dust particles by the method of the Langevin dynamics was performed. The comparisons of experimental and theoretical results are given.

  20. Relativistic addition of parallel velocities from time dilation

    E-Print Network [OSTI]

    Bernhard Rothenstein; Stefan Popescu

    2006-08-11T23:59:59.000Z

    The relativistic addition of parallel velocities is derived involving relativity only via the time dilation formula, avoiding the length contraction used by many authors in conjunction with time dilation. The followed scenario involves a machine gun that fires successive bullets, considered from its rest frame and from the rest frame of the target, the bullets hit.

  1. VELOCITY FIELD OF A ROUND TURBULENT TRANSVERSE JET Suman Muppidi

    E-Print Network [OSTI]

    Mahesh, Krishnan

    - bulent jet in a laminar crossflow. The velocity ratio is 5.7 and the Reynolds number is 5000. Mean Jets in crossflow, also called `transverse jets' are defined as the flow field where a jet of fluid enters and interacts with a crossflowing fluid. Examples of jets in crossflow are fuel injectors

  2. Brady 1D seismic velocity model ambient noise prelim

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Mellors, Robert J.

    Preliminary 1D seismic velocity model derived from ambient noise correlation. 28 Green's functions filtered between 4-10 Hz for Vp, Vs, and Qs were calculated. 1D model estimated for each path. The final model is a median of the individual models. Resolution is best for the top 1 km. Poorly constrained with increasing depth.

  3. Harmonic analysis of the Ha velocity field of NGC 4254

    E-Print Network [OSTI]

    Laurent Chemin; Olivier Hernandez; Chantal Balkowski; Claude Carignan; Philippe Amram

    2005-12-20T23:59:59.000Z

    The ionized gas kinematics of the Virgo Cluster galaxy NGC 4254 (Messier 99) is analyzed by an harmonic decomposition of the velocity field into Fourier coefficients. The aims of this study are to measure the kinematical asymmetries of Virgo cluster galaxies and to connect them to the environment. The analysis reveals significant $m=1,2,4$ terms which origins are discussed.

  4. Brady 1D seismic velocity model ambient noise prelim

    SciTech Connect (OSTI)

    Mellors, Robert J.

    2013-10-25T23:59:59.000Z

    Preliminary 1D seismic velocity model derived from ambient noise correlation. 28 Green's functions filtered between 4-10 Hz for Vp, Vs, and Qs were calculated. 1D model estimated for each path. The final model is a median of the individual models. Resolution is best for the top 1 km. Poorly constrained with increasing depth.

  5. TOWARDS VERTICAL VELOCITY AND HYDROMETEOR CLASSIFICATION FROM ARM WIND PROFILERS

    E-Print Network [OSTI]

    - 98CH10886 with the U.S. Department of Energy. The publisher by accepting the manuscriptTOWARDS VERTICAL VELOCITY AND HYDROMETEOR CLASSIFICATION FROM ARM WIND PROFILERS Scott Giangrande Department/Atmospheric Sciences Division Brookhaven National Laboratory U.S. Department of Energy Office

  6. LAMINAR BURNING VELOCITY OF GASOLINES WITH ADDITION OF ETHANOL

    E-Print Network [OSTI]

    Boyer, Edmond

    1 LAMINAR BURNING VELOCITY OF GASOLINES WITH ADDITION OF ETHANOL P. Dirrenberger1 , P.A. Glaude*1 WITH ADDITION OF ETHANOL P. Dirrenberger1 , P.A. Glaude*1 , R. Bounaceur1 , H. Le Gall1 , A. Pires da Cruz2 , A. The influence of ethanol as an oxygenated additive has been investigated for these two fuels and has been found

  7. Low Velocity Sphere Impact of a Soda Lime Silicate Glass

    SciTech Connect (OSTI)

    Wereszczak, Andrew A [ORNL; Fox, Ethan E [ORNL; Morrissey, Timothy G [ORNL; Vuono, Daniel J [ORNL

    2011-10-01T23:59:59.000Z

    This report summarizes TARDEC-sponsored work at Oak Ridge National Laboratory (ORNL) during the FY11 involving low velocity (< 30 m/s or < 65 mph) ball impact testing of Starphire soda lime silicate glass. The intent was to better understand low velocity impact response in the Starphire for sphere densities that bracketed that of rock. Five sphere materials were used: borosilicate glass, soda-lime silicate glass, steel, silicon nitride, and alumina. A gas gun was fabricated to produce controlled velocity delivery of the spheres against Starphire tile targets. Minimum impact velocities to initiate fracture in the Starphire were measured and interpreted in context to the kinetic energy of impact and the elastic property mismatch between the any of the five sphere-Starphire-target combinations. The primary observations from this low velocity (< 30 m/s or < 65 mph) testing were: (1) Frictional effects contribute to fracture initiation. (2) Spheres with a lower elastic modulus require less force to initiate fracture in the Starphire than spheres with a higher elastic modulus. (3) Contact-induced fracture did not initiate in the Starphire SLS for impact kinetic energies < 150 mJ. Fracture sometimes initiated or kinetic energies between {approx} 150-1100 mJ; however, it tended to occur when lower elastic modulus spheres were impacting it. Contact-induced fracture would always occur for impact energies > 1100 mJ. (4) The force necessary to initiate contact-induced fracture is higher under dynamic or impact conditions than it is under quasi-static indentation conditions. (5) Among the five used sphere materials, silicon nitride was the closest match to 'rock' in terms of both density and (probably) elastic modulus.

  8. Near-Surface Shear-Wave Velocity Measurements in Unlithified Sediment

    E-Print Network [OSTI]

    Rickards, Benjamin Thomas

    2011-05-31T23:59:59.000Z

    with an average S-wave velocity of 600 ft/sec in the top 30 meters as having a relatively high risk for amplifying destructive earthquake waves (Hunter et al., 2010). S-wave studies have also been used to identify subsidence and liquefaction risks for wind-turbine... the method is more challenging geometrically (Kanli, 2008). In fact, it has become common practice to run geological core samples through CAT scans to help determine composition and image bedforms for oil exploration (Stewart, 1991). Medical...

  9. On the Nature of the Radial Velocity Variability of Aldebaran: A Search for Spectral Line Bisector Variations

    E-Print Network [OSTI]

    Artie P. Hatzes; William D. Cochran

    1997-12-23T23:59:59.000Z

    The shape of the Ti I 6303.8 A spectral line of Aldebaran as measured by the line bisector was investigated using high signal-to-noise, high resolution data. The goal of this study was to understand the nature of the 643-day period in the radial velocity for this star reported by Hatzes and Cochran. Variations in the line bisector with the radial velocity period would provide strong evidence in support of rotational modulation or stellar pulsations as the cause of the 643-day period. A lack of any bisector variability at this period would support the planet hypothesis. Variations in the line asymmetries are found with a period of 49.93 days. These variations are uncorrelated with 643-day period found previously in the radial velocity measurements. It is demonstrated that this 50-day period is consistent with an m=4 nonradial sectoral g-mode oscillation. The lack of spectral variability with the radial velocity period of 643 days may provide strong evidence in support of the hypothesis that this variability stems from the reflex motion of the central star due to a planetary companion having a mass of 11 Jupiter masses. However, this long-period variability may still be due to a low order (m=2) pulsation mode since these would cause bisector variations less than the error measurement.

  10. The critical velocity in the BEC-BCS crossover

    E-Print Network [OSTI]

    Wolf Weimer; Kai Morgener; Vijay Pal Singh; Jonas Siegl; Klaus Hueck; Niclas Luick; Ludwig Mathey; Henning Moritz

    2014-08-22T23:59:59.000Z

    We map out the critical velocity in the crossover from Bose-Einstein condensation (BEC) to Bardeen-Cooper-Schrieffer superfluidity with ultracold $^{6}$Li gases. A small attractive potential is dragged along lines of constant column density. The rate of the induced heating increases steeply above a critical velocity $v_c$. In the same samples, we measure the speed of sound $v_s$ by exciting density waves and compare the results to the measured values of $v_c$. We perform numerical simulations in the BEC regime and find very good agreement, validating the approach. In the strongly correlated regime, where theoretical predictions only exist for the speed of sound, our measurements of $v_c$ provide a testing ground for theoretical approaches.

  11. Velocity tuning of friction with two trapped atoms

    E-Print Network [OSTI]

    Gangloff, Dorian; Counts, Ian; Jhe, Wonho; Vuleti?, Vladan

    2015-01-01T23:59:59.000Z

    Friction is the basic, ubiquitous mechanical interaction between two surfaces that results in resistance to motion and energy dissipation. In spite of its technological and economic significance, our ability to control friction remains modest, and our understanding of the microscopic processes incomplete. At the atomic scale, mismatch between the two contacting crystal lattices can lead to a reduction of stick-slip friction (structural lubricity), while thermally activated atomic motion can give rise to a complex velocity dependence, and nearly vanishing friction at sufficiently low velocities (thermal lubricity). Atomic force microscopy has provided a wealth of experimental results, but limitations in the dynamic range, time resolution, and control at the single-atom level have hampered a full quantitative description from first principles. Here, using an ion-crystal friction emulator with single-atom, single substrate-site spatial resolution and single-slip temporal resolution, we measure the friction force...

  12. The AMS-RICH velocity and charge reconstruction

    E-Print Network [OSTI]

    F. Barao; M. Aguilar-Benitez; L. Arruda; B. Baret; A. Barrau; G. Barreira; E. Belmont; J. Berdugo; J. Borges; M. Buenerd; D. Casadei; J. Casaus; E. Cortina; M. Costado; D. Crespo; C. Delgado; C. Diaz; L. Derome; P. Goncalves; R. Garcia-Lopez; C. de la Guia; A. Herrero; E. Lanciotti; G. Laurenti; A. Malinin; C. Mana; J. Marin; M. Mangin-Brinet; G. Martinez; A. Menchaca-Rocha; C. Palomares; R. Pereira; M. Pimenta; A. Putze; Y. Sallaz-Damaz; E. S. Seo; I. Sevilla; A. Torrento; M. Vargas-Trevino; O. Veziant

    2007-09-13T23:59:59.000Z

    The AMS detector, to be installed on the International Space Station, includes a Ring Imaging Cerenkov detector with two different radiators, silica aerogel (n=1.05) and sodium fluoride (n=1.334). This detector is designed to provide very precise measurements of velocity and electric charge in a wide range of cosmic nuclei energies and atomic numbers. The detector geometry, in particular the presence of a reflector for acceptance purposes, leads to complex Cerenkov patterns detected in a pixelized photomultiplier matrix. The results of different reconstruction methods applied to test beam data as well as to simulated samples are presented. To ensure nominal performances throughout the flight, several detector parameters have to be carefully monitored. The algorithms developed to fulfill these requirements are presented. The velocity and charge measurements provided by the RICH detector endow the AMS spectrometer with precise particle identification capabilities in a wide energy range. The expected performances on light isotope separation are discussed.

  13. Velocity renormalization in graphene from lattice Monte Carlo

    E-Print Network [OSTI]

    Joaquín E. Drut; Timo A. Lähde

    2014-03-26T23:59:59.000Z

    We compute the Fermi velocity of the Dirac quasiparticles in clean graphene at the charge neutrality point for strong Coulomb coupling alpha_g. We perform a Lattice Monte Carlo calculation within the low-energy Dirac theory, which includes an instantaneous, long-range Coulomb interaction. We find a renormalized Fermi velocity v_FR > v_F, where v_F = c/300. Our results are consistent with a momentum-independent v_FR which increases approximately linearly with alpha_g, although a logarithmic running with momentum cannot be excluded at present. At the predicted critical coupling alpha_gc for the semimetal-insulator transition due to excitonic pair formation, we find v_FR/v_F = 3.3, which we discuss in light of experimental findings for v_FR/v_F at the charge neutrality point in ultra-clean suspended graphene.

  14. Predicting stress-induced velocity anisotropy in rocks

    SciTech Connect (OSTI)

    Mavko, G.; Mukerji, T.; Godfrey, N. [Stanford Univ., CA (United States). Rock Physics Lab.] [Stanford Univ., CA (United States). Rock Physics Lab.

    1995-07-01T23:59:59.000Z

    A simple transformation, using measured isotropic V{sub P} and V{sub S} versus hydrostatic pressure, is presented for predicting stress-induced seismic velocity anisotropy in rocks. The compliant, crack-like portions of the pore space are characterized by generalized compressional and shear compliances that are estimated form the isotropic V{sub P} and V{sub S}. The physical assumption that the compliant porosity is crack-like means that the pressure dependence of the generalized compliances is governed primarily by normal tractions resolved across cracks and defects. This allows the measured pressure dependence to be mapped form the hydrostatic stress state to any applied nonhydrostatic stress. Predicted P- and S-wave velocities agree reasonably well with uniaxial stress data for Barre Granite and Massillon Sandstone. While it is mechanically similar to methods based on idealized ellipsoidal cracks, the approach is relatively independent of any assumed crack geometry and is not limited to small crack densities.

  15. Low velocity ion stopping in binary ionic mixtures

    SciTech Connect (OSTI)

    Tashev, Bekbolat; Baimbetov, Fazylkhan [Department of Physics, Kazakh National University, Tole Bi 96, Almaty 480012 (Kazakhstan); Deutsch, Claude [LPGP (UMR-CNRS 8578), Universite Paris XI, 91405 Orsay (France); Fromy, Patrice [Direction de l'Informatique, Universite Paris XI, 91405 Orsay (France)

    2008-10-15T23:59:59.000Z

    Attention is focused on the low ion velocity stopping mechanisms in multicomponent and dense target plasmas built of quasiclassical electron fluids neutralizing binary ionic mixtures, such as, deuterium-tritium of current fusion interest, proton-heliumlike iron in the solar interior or proton-helium ions considered in planetology, as well as other mixtures of fiducial concern in the heavy ion beam production of warm dense matter at Bragg peak conditions. The target plasma is taken in a multicomponent dielectric formulation a la Fried-Conte. The occurrence of projectile ion velocities (so-called critical) for which target electron slowing down equals that of given target ion components is also considered. The corresponding multiquadrature computations, albeit rather heavy, can be monitored analytical through a very compact code operating a PC cluster. Slowing down results are systematically scanned with respect to target temperature and electron density, as well as ion composition.

  16. Maximum velocity of self-propulsion for an active segment

    E-Print Network [OSTI]

    Recho, Pierre

    2015-01-01T23:59:59.000Z

    The motor part of a crawling eukaryotic cell can be represented schematically as an active continuum layer. The main active processes in this layer are protrusion, originating from non-equilibrium polymerization of actin fibers, contraction, induced by myosin molecular motors and attachment due to active bonding of trans-membrane proteins to a substrate. All three active mechanisms are regulated by complex signaling pathways involving chemical and mechanical feedback loops whose microscopic functioning is still poorly understood. In this situation, it is instructive to take a reverse engineering approach and study a problem of finding the spatial organization of standard active elements inside a crawling layer ensuring an optimal cost-performance trade-off. In this paper we assume that (in the range of interest) the energetic cost of self-propulsion is velocity independent and adopt, as an optimality criterion, the maximization of the overall velocity. We then choose a prototypical setting, formulate the corr...

  17. THE RADIAL VELOCITY EXPERIMENT (RAVE): FOURTH DATA RELEASE

    SciTech Connect (OSTI)

    Kordopatis, G.; Gilmore, G. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge, CB3 0HA (United Kingdom); Steinmetz, M.; Williams, M. E. K.; Piffl, T.; Enke, H.; Carrillo, I. [Leibniz-Institut für Astrophysik Potsdam, An der Sternwarte 16, D-14482 Potsdam (Germany); Boeche, C.; Roeser, S. [Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg, Mönchhofstr. 12-14, D-69120 Heidelberg (Germany); Seabroke, G. M. [Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Dorking, Surrey, RH5 6NT (United Kingdom); Siebert, A. [Observatoire Astronomique de Strasbourg, Université de Strasbourg, CNRS, UMR 7550, 11 rue de l'Université, F-67000 Strasbourg (France); Zwitter, T. [Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, 1000 Ljubljana (Slovenia); Binney, J. [Rudolf Peierls Centre for Theoretical Physics, Keble Road, Oxford, OX1 3NP (United Kingdom); De Laverny, P.; Recio-Blanco, A.; Bijaoui, A. [Laboratoire Lagrange, UMR 7293, Université de Nice Sophia Antipolis, CNRS, Observatoire de la Côte d'Azur, BP4229, F-06304 Nice (France); Wyse, R. F. G. [Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Freeman, K. [Research School of Astronomy and Astrophysics, Australian National University, Cotter Road, Weston, ACT 2611 (Australia); Munari, U. [INAF National Institute of Astrophysics, Astronomical Institute of Padova, I-36012 Asiago (VI) (Italy); Anguiano, B., E-mail: gkordo@ast.cam.ac.uk [Australian Astronomical Observatory, P.O. Box 915, North Ryde, NSW 1670 (Australia); and others

    2013-11-01T23:59:59.000Z

    We present the stellar atmospheric parameters (effective temperature, surface gravity, overall metallicity), radial velocities, individual abundances, and distances determined for 425,561 stars, which constitute the fourth public data release of the RAdial Velocity Experiment (RAVE). The stellar atmospheric parameters are computed using a new pipeline, based on the algorithms of MATISSE and DEGAS. The spectral degeneracies and the Two Micron All Sky Survey photometric information are now better taken into consideration, improving the parameter determination compared to the previous RAVE data releases. The individual abundances for six elements (magnesium, aluminum, silicon, titanium, iron, and nickel) are also given, based on a special-purpose pipeline that is also improved compared to that available for the RAVE DR3 and Chemical DR1 data releases. Together with photometric information and proper motions, these data can be retrieved from the RAVE collaboration Web site and the Vizier database.

  18. Astrometric determination of white dwarf radial velocities with Gaia?

    E-Print Network [OSTI]

    Jordan, Stefan

    2012-01-01T23:59:59.000Z

    Usually, the determination of radial velocities of stars relies on the shift of spectral lines by the Doppler effect. Russel & Atkinson (1931) and Oort (1932) already noted that due to the large proper motion and parallax of the white dwarf (WD) van Maanen 2, a determination of the perspective acceleration of the proper motion would provide a direct astrometric determination of the radial velocity which is independent of the gravitational redshift. If spectroscopic redshift measurements of Halpha and Hbeta NLTE cores exist, a purely astrometric determination would allow disentangling the gravitational redshift from the Doppler shift. The best instrument for measuring the tiny perspective acceleration is the Gaia satellite of the European Space Agency, aiming at absolute astrometric measurements of one billion stars down to 20th magnitude with unprecedented accuracy. At 15th magnitude, the predicted angular accuracy of Gaia is about 20 micro-arcseconds. In this article, we estimate whether it is possible t...

  19. Time, Distance, Velocity, Redshift: a personal guided tour

    E-Print Network [OSTI]

    T. Kiang

    2003-08-01T23:59:59.000Z

    An attempt to answer the question 'Can we observe galaxies that recede faster than light ?' led to a re-examination of the notions of time, distance, velocity and redshift as they occur in newtonian physics, special relativity, general relativity and cosmology. A number of misconceptions were uncovered. It was found that, once freed of special relativity preconceptions, the above question is easily and unequivocally answered

  20. Dynamic slip velocity correlation using non-spherical particles

    E-Print Network [OSTI]

    Pecore, Douglas Wilkin

    1990-01-01T23:59:59.000Z

    GRAMS FIGURE 39: FREQUENCY DISTRIBUTION, STATIC, MUD WEIGHT RANGE: 0. 5 - 0. 6 GRAMS FIGURE 40: FREQUENCY DISTRIBUTION, STATIC, MUD WEIGHT RANGE: 0. 6 - 0. 7 GRAMS FIGURE 41: FREQUENCY DISTRIBUTION, STATIC, MUD WEIGHT RANGE: 0. 7 - 0, 8 GRAMS... of Advisory Committee: Dr. Hans C. Juvkam-Wold This research proposes a method for calculating the slip velocity of irregularly shaped particles falling in non-Newtonian fluids in a vertical flow conduit under static and dynamic flow conditions. A...