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Note: This page contains sample records for the topic "duct high velocity" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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1

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

E-Print Network [OSTI]

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

Stancil, Daniel D.

2

Design and Evaluation of a High Temperature Burner Duct Recuperator System  

E-Print Network [OSTI]

"The Babcock & Wilcox Company (B&W) has completed a program to design, construct, install, and field test a ceramic-based high-temperature burner-duct-recuperator (HTBDR) in an industrial setting. The unit was capable of operating in corrosive, high...

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

3

High-velocity clouds: a diverse phenomenon  

E-Print Network [OSTI]

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.

B. P. Wakker

2001-09-13T23:59:59.000Z

4

Particle deposition in ventilation ducts: Connectors, bends anddeveloping flow  

SciTech Connect (OSTI)

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.

Sippola, Mark R.; Nazaroff, William W.

2004-03-01T23:59:59.000Z

5

An insitu borescopic quantitative imaging profiler for the measurement of high concentration sediment velocity  

E-Print Network [OSTI]

of high concentration sediment velocity Edwin A. Cowen •instantaneous velocity in high sediment concentration ?ows,point reveals the sheet ?ow sediment velocities to be highly

Cowen, Edwin A.; Dudley, Russell D.; Liao, Qian; Variano, Evan A.; Liu, Philip L.-F.

2010-01-01T23:59:59.000Z

6

Lensing duct  

DOE Patents [OSTI]

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.

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

1994-04-26T23:59:59.000Z

7

Experimental High Velocity Acid Jetting in Limestone Carbonates  

E-Print Network [OSTI]

Acid jetting is a well stimulation technique that is used in carbonate reservoirs. It typically involves injecting acid down hole at high flow rates through small orifices which cause high velocities of acid to strike the borehole wall...

Holland, Christopher

2014-04-30T23:59:59.000Z

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]

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

Stancil, Daniel D.

9

Superconducting spoke cavities for high-velocity applications  

SciTech Connect (OSTI)

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.

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

2013-10-01T23:59:59.000Z

10

MAGNETIZED GAS IN THE SMITH HIGH VELOCITY CLOUD  

SciTech Connect (OSTI)

We report the first detection of magnetic fields associated with the Smith High Velocity Cloud. We use a catalog of Faraday rotation measures toward extragalactic radio sources behind the Smith Cloud, new H I observations from the Robert C. Byrd Green Bank Telescope, and a spectroscopic map of H? from the Wisconsin H-Alpha Mapper Northern Sky Survey. There are enhancements in rotation measure (RM) of ?100 rad m{sup –2} which are generally well correlated with decelerated H? emission. We estimate a lower limit on the line-of-sight component of the field of ?8 ?G along a decelerated filament; this is a lower limit due to our assumptions about the geometry. No RM excess is evident in sightlines dominated by H I or H? at the velocity of the Smith Cloud. The smooth H? morphology of the emission at the Smith Cloud velocity suggests photoionization by the Galactic ionizing radiation field as the dominant ionization mechanism, while the filamentary morphology and high (?1 Rayleigh) H? intensity of the lower-velocity magnetized ionized gas suggests an ionization process associated with shocks due to interaction with the Galactic interstellar medium. The presence of the magnetic field may contribute to the survival of high velocity clouds like the Smith Cloud as they move from the Galactic halo to the disk. We expect these data to provide a test for magnetohydrodynamic simulations of infalling gas.

Hill, Alex S.; McClure-Griffiths, Naomi M. [CSIRO Astronomy and Space Science, Marsfield, NSW (Australia); Mao, S. A. [Department of Astronomy, University of Wisconsin-Madison, Madison, WI (United States); Benjamin, Robert A. [Department of Physics, University of Wisconsin-Whitewater, Whitewater, WI (United States); Lockman, Felix J., E-mail: alex.hill@csiro.au, E-mail: naomi.mcclure-griffiths@csiro.au, E-mail: mao@astro.wisc.edu, E-mail: benjamir@uww.edu, E-mail: jlockman@nrao.edu [National Radio Astronomy Observatory, Green Bank, WV (United States)

2013-11-01T23:59:59.000Z

11

High-Velocity Oxygen Fuel Thermal Spray of Fe-Based Amorphous Alloy: a Numerical and Experimental Study  

E-Print Network [OSTI]

High-Velocity Oxygen Fuel Thermal Spray of Fe-Basedusing a high velocity oxygen fuel (HVOF) spray processstructure. [12] High velocity oxygen fuel (HVOF) thermal

Ajdelsztajn, L.; Dannenberg, J.; Lopez, J.; Yang, N.; Farmer, J.; Lavernia, E. J.

2009-01-01T23:59:59.000Z

12

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

E-Print Network [OSTI]

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.

Jian-Miin Liu

2001-08-18T23:59:59.000Z

13

Arecibo imaging of compact high-velocity clouds  

E-Print Network [OSTI]

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...

Burton, W B; Chengalur, J N

2001-01-01T23:59:59.000Z

14

Arecibo imaging of compact high-velocity clouds  

E-Print Network [OSTI]

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 (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)

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

2001-02-06T23:59:59.000Z

15

Hollow lensing duct  

DOE Patents [OSTI]

A hollow lensing duct to condense (intensify) light using a combination of focusing using a spherical or cylindrical lens followed by reflective waveguiding. The hollow duct tapers down from a wide input side to a narrow output side, with the input side consisting of a lens that may be coated with an antireflective coating for more efficient transmission into the duct. The inside surfaces of the hollow lens duct are appropriately coated to be reflective, preventing light from escaping by reflection as it travels along the duct (reflective waveguiding). The hollow duct has various applications for intensifying light, such as in the coupling of diode array pump light to solid state lasing materials.

Beach, Raymond J. (Livermore, CA); Honea, Eric C. (Sunol, CA); Bibeau, Camille (Dublin, CA); Mitchell, Scott (Tracy, CA); Lang, John (Pleasanton, CA); Maderas, Dennis (Pleasanton, CA); Speth, Joel (San Ramon, CA); Payne, Stephen A. (Castro Valley, CA)

2000-01-01T23:59:59.000Z

16

Distances and Metallicities of High- and Intermediate-Velocity Clouds  

E-Print Network [OSTI]

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.

B. P. Wakker

2001-02-08T23:59:59.000Z

17

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

DOE Patents [OSTI]

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.

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

1990-10-16T23:59:59.000Z

18

Low inlet gas velocity high throughput biomass gasifier  

DOE Patents [OSTI]

The present invention discloses a novel method of operating a gasifier for production of fuel gas from carbonaceous fuels. The process disclosed enables operating in an entrained mode using inlet gas velocities of less than 7 feet per second, feedstock throughputs exceeding 4000 lbs/ft.sup.2 -hr, and pressures below 100 psia.

Feldmann, Herman F. (Worthington, OH); Paisley, Mark A. (Upper Arlington, OH)

1989-01-01T23:59:59.000Z

19

Pneumatic cleaning of sugarcane utilizing a high velocity air jet  

E-Print Network [OSTI]

- oped to cope with the increased amount of trash present in unburned sugarcane. This research involved the testing and computer simulation of a chopper air jet nozzle assembly. The experimental test setup included a two-stage conveyor. This conveyor... of the system was evaluated. The results of the chopper air jet nozzle assembly tests verified that the air velocity, nozzle size, chopper blade configuration and feed-in rate contributed signifi- cantly to the cleanliness of the billets. The air velo- city...

Fisher, John Ray

2012-06-07T23:59:59.000Z

20

Hohlraum Designs for High Velocity Implosions on NIF  

SciTech Connect (OSTI)

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%.

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

Note: This page contains sample records for the topic "duct high velocity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Advanced Duct Sealing Testing  

SciTech Connect (OSTI)

Duct leakage has been identified as 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 typically shown that these seals tend to fail over extended periods of time. The Lawrence Berkeley National Laboratory has been testing sealant durability for several years. Typical duct tape (i.e. fabric backed tapes with natural rubber adhesives) was found to fail more rapidly than all other duct sealants. This report summarizes the results of duct sealant durability testing of five UL 181B-FX listed duct tapes (three 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 first test involved the aging of common ''core-to-collar joints'' of flexible duct to sheet metal collars, and sheet metal ''collar-to-plenum joints'' pressurized with 200 F (93 C) air. The second test consisted of baking duct tape specimens in a constant 212 F (100 C) oven following the UL 181B-FX ''Temperature Test'' requirements. Additional tests were also performed on only two tapes using sheet metal collar-to-plenum joints. Since an unsealed flexible duct joint can have a variable leakage depending on the positioning of the flexible duct core, the durability of the flexible duct joints could not be based on the 10% of unsealed leakage criteria. Nevertheless, the leakage of the sealed specimens prior to testing could be considered as a basis for a failure criteria. Visual inspection was also documented throughout the tests. The flexible duct core-to-collar joints were inspected monthly, while the sheet metal collar-to-plenum joints were inspected weekly. The baking test specimens were visually inspected weekly, and the durability was judged by the observed deterioration in terms of brittleness, cracking, flaking and blistering (the terminology used in the UL 181B-FX test procedure).

Sherman, Max H.; Walker, Iain S.

2003-08-01T23:59:59.000Z

22

Duct Tape Durability Testing  

SciTech Connect (OSTI)

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).

Sherman, Max H.; Walker, Iain S.

2004-04-01T23:59:59.000Z

23

Variables Affecting Smooth Particle Hydrodynamics Simulation of High-Velocity Flyer Plate Impact Experiments  

SciTech Connect (OSTI)

This paper describes our work to characterize the variables affecting the smoothed particle hydrodynamics (SPH) method in the LS-DYNA package for simulating high-velocity flyer plate impact experiments. LS-DYNA simulations are compared with one-dimensional experimental data of an oxygen-free high-conductivity (OFHC) copper flyer plate impacting another plate of the same material. The comparison is made by measuring the velocity of a point on the back surface of the impact plate using the velocity interferometer system for any reflector (VISAR) technique.

Somasundaram, Deepak S [UNLV; Trabia, Mohamed [UNLV; O'Toole, Brendan [UNLV; Hixson, Robert S [NSTec

2014-01-23T23:59:59.000Z

24

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

E-Print Network [OSTI]

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.

Eyal Maoz; Christopher F. McKee

1997-04-04T23:59:59.000Z

25

T-method duct design. Part 4: Duct leakage theory  

SciTech Connect (OSTI)

Studies have shown that duct leakage depends on the method of duct fabrication, method of sealing, workmanship, and static pressure differential. An equation that describes leakage as a function of leakage class and static pressure is presented in the Duct Design chapter of the 1993 ASHRAE Handbook. This equation is used to calculate the leakage rate through a unit of duct surface for constant duct static pressure. However, the static pressure of a leaking duct does not remain constant. This process is described by a differential equation. The magnitude of duct leakage for a straight duct depends on internal static pressure and varies uniformly along its length (assumption). Fittings in a system cause sudden changes in static pressure; therefore, duct leakage depends on fitting locations. There are two approaches for duct system leakage calculation: (1) Accurate -- For accurate duct leakage calculations, the duct system is divided into single sections between fittings and the leakage rate and pressure loss for each section calculated by the weighing factor method. (2) Approximate -- For most applications, duct leakage can be calculated by approximate formulas based on the average static pressure in a duct section. Leakage calculation requires dividing the system into sections between each fitting. This paper, the fourth in a series on T-method duct design, discusses the theory of calculating air leakage from/into a single duct to incorporate duct leakage into the optimization and simulation calculation procedures.

Tsal, R.J.; Varvak, L.P. [NETSAL and Associates, Fountain Valley, CA (United States); Behls, H.F. [Behls and Associates, Arlington Heights, IL (United States)

1998-12-31T23:59:59.000Z

26

Turbulent flame speeds in ducts and the deflagration/detonation transition  

SciTech Connect (OSTI)

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)

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

2008-07-15T23:59:59.000Z

27

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

E-Print Network [OSTI]

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

Wooldridge, Margaret S.

28

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

SciTech Connect (OSTI)

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.

Sippola, Mark R.; Nazaroff, William W.

2003-08-01T23:59:59.000Z

29

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

SciTech Connect (OSTI)

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.

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

30

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

E-Print Network [OSTI]

"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...

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

2015-01-01T23:59:59.000Z

31

Particle deposition in ventilation ducts  

SciTech Connect (OSTI)

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.

Sippola, Mark R.

2002-09-01T23:59:59.000Z

32

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

E-Print Network [OSTI]

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.

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

1999-07-08T23:59:59.000Z

33

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

E-Print Network [OSTI]

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^...

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

34

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

DOE Patents [OSTI]

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.

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

1999-01-01T23:59:59.000Z

35

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

SciTech Connect (OSTI)

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.

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

2008-09-20T23:59:59.000Z

36

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

SciTech Connect (OSTI)

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.

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

37

RATIONALE FOR MEASURING DUCT LEAKAGE FLOWS IN LARGE COMMERCIAL BUILDINGS  

E-Print Network [OSTI]

. Some duct sections operate at high static pressures (e.g., 100 to 2,500 Pa), but other sections leakage flows is to assume that an average duct static pressure applies to every leak. A third important2 ), central HVAC systems continuously supply heated or cooled air to conditioned spaces through

Diamond, Richard

38

Cornice Duct System  

SciTech Connect (OSTI)

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.

Wayne Place; Chuck Ladd

2004-10-29T23:59:59.000Z

39

Smith's Cloud: A High-velocity Cloud Colliding with the Milky Way  

E-Print Network [OSTI]

New 21cm HI observations made with the Green Bank Telescope show that the high-velocity cloud known as Smith's Cloud has a striking cometary appearance and many indications of interaction with the Galactic ISM. The velocities of interaction give a kinematic distance of 12.4 +/-1.3 kpc, consistent with the distance derived from other methods. The Cloud is >3 x 1 kpc in size and its tip at (l,b)=(39 deg,-13 deg) is 7.6 kpc from the Galactic center and 2.9 kpc below the Galactic plane. It has greater than 10^6 M solar masses in HI. Its leading section has a total space velocity near 300 km/s, is moving toward the Galactic plane with a velocity of 73+/-26 km/s, and is shedding material to the Galaxy. In the absence of drag the Cloud will cross the plane in about 27 Myr. Smith's Cloud may be an example of the accretion of gas by the Milky Way needed to explain certain persistent anomalies in Galactic chemical evolution.

Lockman, Felix J; Heroux, A J; Langston, Glen I

2008-01-01T23:59:59.000Z

40

Smith's Cloud: A High-velocity Cloud Colliding with the Milky Way  

E-Print Network [OSTI]

New 21cm HI observations made with the Green Bank Telescope show that the high-velocity cloud known as Smith's Cloud has a striking cometary appearance and many indications of interaction with the Galactic ISM. The velocities of interaction give a kinematic distance of 12.4 +/-1.3 kpc, consistent with the distance derived from other methods. The Cloud is >3 x 1 kpc in size and its tip at (l,b)=(39 deg,-13 deg) is 7.6 kpc from the Galactic center and 2.9 kpc below the Galactic plane. It has greater than 10^6 M solar masses in HI. Its leading section has a total space velocity near 300 km/s, is moving toward the Galactic plane with a velocity of 73+/-26 km/s, and is shedding material to the Galaxy. In the absence of drag the Cloud will cross the plane in about 27 Myr. Smith's Cloud may be an example of the accretion of gas by the Milky Way needed to explain certain persistent anomalies in Galactic chemical evolution.

Felix J. Lockman; Robert A. Benjamin; A. J. Heroux; Glen I. Langston

2008-04-25T23:59:59.000Z

Note: This page contains sample records for the topic "duct high velocity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

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

E-Print Network [OSTI]

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...

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

42

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

SciTech Connect (OSTI)

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.

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

43

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

SciTech Connect (OSTI)

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.

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

1995-05-01T23:59:59.000Z

44

Duct thermal performance models for large commercial buildings  

SciTech Connect (OSTI)

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.

Wray, Craig P.

2003-10-01T23:59:59.000Z

45

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.

46

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

SciTech Connect (OSTI)

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.

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

47

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

SciTech Connect (OSTI)

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.

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

48

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...

49

The Ultra Luminous X-ray sources in the High Velocity System of NGC 1275  

E-Print Network [OSTI]

We report the results of a study of X-ray point sources coincident with the High Velocity System (HVS) projected in front of NGC 1275. A very deep X-ray image of the core of the Perseus cluster made with the Chandra Observatory has been used. We find a population of Ultra-Luminous X-ray sources (ULX; 7 sources with LX [0.5-7 keV] > 7x10^39 erg/s). As with the ULX populations in the Antennae and Cartwheel galaxies, those in the HVS are associated with a region of very active star formation. Several sources have possible optical counterparts found on HST images, although the X-ray brightest one does not. Absorbed power-law models fit the X-ray spectra, with most having a photon index between 2 and 3.

O. Gonzalez-Martin; A. C. Fabian; J. S. Sanders

2006-01-09T23:59:59.000Z

50

Sealing ducts to save energy  

SciTech Connect (OSTI)

Large amounts of energy are wasted when heat leaks through ductwork located in uninsulated spaces. The Electric Power Research INstitute recently did a study that accurately measured these losses, then substantially reduced them by sealing the leaky ductwork. Six homes in the Pacific Northwest with significant duct leakage to the outside were selected for the study. The homes had electric resistance or heat pump, forced-air heating systems with a major portion of the supply and return ductwork in crawl spaces, attics, garages, etc. Measurements of duct leakage and heating system efficiency were done on all the homes before starting the duct sealing. Retrofitting included finding holes, gaps, cracks and disconnected joints in supply and return ducts as well as in plenums. When necessary, plenums were cut open for repairs. Leaks were sealed with Latex mastic and fiberglass tape. Outside ducts were covered or wrapped with insulation. Unducted returns were sealed with duct board. In some cases, leakage was corrected by merely reconnecting ducts and boots.

Siuru, B.

1996-07-01T23:59:59.000Z

51

E-Print Network 3.0 - activated combustion-high velocity Sample...  

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

velocity model of an area in the lower part... and complex slope movements in the South French Alps. The landslide associates two styles of activity Source: Ecole Polytechnique,...

52

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

53

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

E-Print Network [OSTI]

of HVAC Duct Channel for High-Speed Internet Access Ariton E. Xhafa, Member, IEEE, Ozan K. Tonguz, Member and experimental channel-capacity estimates of heating, ventilation, and air condi- tioning (HVAC) ducts based suppressed. Our experimental results also show that even in the case of more complex HVAC duct networks (i

Stancil, Daniel D.

54

The Double Seismic Zone of the Nazca Plate in Northern Chile: High Resolution Velocity Structure, Petrological Implications and  

E-Print Network [OSTI]

The Double Seismic Zone of the Nazca Plate in Northern Chile: High Resolution Velocity Structure presents an interdisciplinary study of the Northern Chile Double Seismic Zone. First, a high resolution method. The double seismic zone (DSZ) is observed between 80 and 140 km depth and the two seismic planes

Paris-Sud XI, Université de

55

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

E-Print Network [OSTI]

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

Suslick, Kenneth S.

56

Articulated transition duct in turbomachine  

DOE Patents [OSTI]

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.

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

2014-04-29T23:59:59.000Z

57

Impact fracture behavior of HT9 duct  

SciTech Connect (OSTI)

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.

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

58

The Smith Cloud: high-velocity accretion and dark-matter confinement  

E-Print Network [OSTI]

The Smith Cloud is a massive system of metal-poor neutral and ionized gas M_gas >= 2x10^6 M_sun) that is presently moving at high velocity (V_GSR ~300 km s^-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. (2008). 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 (NFW, Einasto, 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...

Nichols, M

2009-01-01T23:59:59.000Z

59

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

E-Print Network [OSTI]

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.

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

2014-06-30T23:59:59.000Z

60

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

E-Print Network [OSTI]

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.

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

2008-02-20T23:59:59.000Z

Note: This page contains sample records for the topic "duct high velocity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

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

E-Print Network [OSTI]

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...

Stephen, Alton Lee

1968-01-01T23:59:59.000Z

62

Characterization and Fabrication of Spoke Cavities for High-Velocity Applications  

SciTech Connect (OSTI)

A 500 MHz, velocity-of-light, two-spoke cavity has been designed and optimized for possible use in a compact light source. Here we present the mechanical analysis and steps taken in fabrication of this cavity at Jefferson Lab.

Hopper, Christopher S. [Old Dominion University, Norfolk, VA (United States); Park, HyeKyoung [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Delayen, Jean R. [Old Dominion University, Norfolk, VA (United States)

2014-02-01T23:59:59.000Z

63

Achieving Airtight Ducts in Manufactured Housing  

E-Print Network [OSTI]

correlated with achieving CFM25OUT=3% in mastic sealed systems, but less reliably with taped systems. Cost for achieving duct tightness goals range from $4 to $8 including duct testing on the assembly line...

McIlvaine, J.; Beal, D.; Moyer, N.; Chasar, D.; Chandra, S.

2004-01-01T23:59:59.000Z

64

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

65

Measurements of Smoke Characteristics in HVAC Ducts   

E-Print Network [OSTI]

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...

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

2001-01-01T23:59:59.000Z

66

Particle deposition in ventilation ducts  

E-Print Network [OSTI]

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

Sippola, Mark R.

2002-01-01T23:59:59.000Z

67

CALIFORNIA ENERGY Residential Duct Placement  

E-Print Network [OSTI]

through the integrated design, construction, and operation of building systems. The Integrated Energy Systems Integrated Design of Commercial Building Ceiling Systems Integrated Design of Residential Ducting;#12;ACKNOWLEDGEMENTS The products and outcomes presented in this report are part of the Integrated Design

68

Stochastic simulation for the propagation of high-frequency acoustic waves through a random velocity field  

SciTech Connect (OSTI)

In-service inspection of Sodium-Cooled Fast Reactors (SFR) requires the development of non-destructive techniques adapted to the harsh environment conditions and the examination complexity. From past experiences, ultrasonic techniques are considered as suitable candidates. The ultrasonic telemetry is a technique used to constantly insure the safe functioning of reactor inner components by determining their exact position: it consists in measuring the time of flight of the ultrasonic response obtained after propagation of a pulse emitted by a transducer and its interaction with the targets. While in-service the sodium flow creates turbulences that lead to temperature inhomogeneities, which translates into ultrasonic velocity inhomogeneities. These velocity variations could directly impact the accuracy of the target locating by introducing time of flight variations. A stochastic simulation model has been developed to calculate the propagation of ultrasonic waves in such an inhomogeneous medium. Using this approach, the travel time is randomly generated by a stochastic process whose inputs are the statistical moments of travel times known analytically. The stochastic model predicts beam deviations due to velocity inhomogeneities, which are similar to those provided by a determinist method, such as the ray method.

Lu, B.; Darmon, M.; Leymarie, N.; Chatillon, S.; Potel, C. [CEA, LIST, F-91191 Gif-sur-Yvette (France); Laboratoire d'Acoustique de l'Universite du Maine (LAUM), UMR CNRS 6613, 72085 Le Mans Cedex 9 (France)

2012-05-17T23:59:59.000Z

69

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

E-Print Network [OSTI]

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

Jackson, Jennifer M.

70

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

SciTech Connect (OSTI)

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.

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

2013-12-01T23:59:59.000Z

71

A Catalog of Ultra-compact High Velocity Clouds from the ALFALFA Survey: Local Group Galaxy Candidates?  

E-Print Network [OSTI]

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, median angular diameters of 10', and median velocity widths of 23 km/s. 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 ~1 Mpc, the UCHVCs have neutral hydrogen (HI) masses of ~10^5 -10^6 M_sun, HI diamet...

Adams, Elizabeth A K; Haynes, Martha P

2013-01-01T23:59:59.000Z

72

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...

73

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

SciTech Connect (OSTI)

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.

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

74

Computer Aided Duct Design  

E-Print Network [OSTI]

is designed with a higher static pressure and greater noise and turbulence than is necessary. A computer model helps to resolve these problems, reducing the fan horsepower needed to deliver the air. Computer optimization also reduces noise and the high rate...

Clark, W. H.

1994-01-01T23:59:59.000Z

75

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

SciTech Connect (OSTI)

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.

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

76

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

E-Print Network [OSTI]

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...

Mendoza, Nicole Renee

2013-04-29T23:59:59.000Z

77

Measure Guideline: Sealing and Insulating of Ducts in Existing Homes  

SciTech Connect (OSTI)

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.

Aldrich, R.; Puttagunta, S.

2011-12-01T23:59:59.000Z

78

Compression effects on pressure loss in flexible HVAC ducts  

E-Print Network [OSTI]

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.

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

2002-01-01T23:59:59.000Z

79

Effect of refrigerant charge, duct leakage, and evaporator air flow on the high temerature performance of air conditioners and heat pumps.  

E-Print Network [OSTI]

??An experimental study was conducted to quantify the effect of several installation items on the high outdoor ambient temperature performance of air conditioners. These installation… (more)

Rodriguez, Angel Gerardo

2012-01-01T23:59:59.000Z

80

Laser-based diagnostics for density, temperature, velocity, and dissociation fraction in high temperature hydrogen flows  

SciTech Connect (OSTI)

This paper is essentially a review of the current state of the art in hydrogen atom and hydrogen molecule diagnostics. This paper contains some of our own results and ideas along with results from many other laboratories. This is not intended to be an exhaustive review; instead it summarizes some techniques which we believe are ideally suited as diagnostics for high temperature hydrogen which are of paramount importance for the Space Exploration Initiative (SEI). 31 refs., 1 fig.

Sappey, A.D.; Funk, D.J.

1991-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "duct high velocity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Double-duct liquid metal magnetohydrodynamic engine  

DOE Patents [OSTI]

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.

Haaland, Carsten M. (Oak Ridge, TN)

1997-01-01T23:59:59.000Z

82

Double-duct liquid metal magnetohydrodynamic engine  

DOE Patents [OSTI]

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.

Haaland, Carsten M. (Oak Ridge, TN)

1995-01-01T23:59:59.000Z

83

Effect of refrigerant charge, duct leakage, and evaporator air flow on the high temerature performance of air conditioners and heat pumps  

E-Print Network [OSTI]

An experimental study was conducted to quantify the effect of several installation items on the high outdoor ambient temperature performance of air conditioners. These installation items were: improper amount of refrigerant charge, reduced...

Rodriguez, Angel Gerardo

2012-06-07T23:59:59.000Z

84

Integration of HVAC System Design with Simplified Duct Distribution...  

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

Integration of HVAC System Design with Simplified Duct Distribution - Building America Top Innovation Integration of HVAC System Design with Simplified Duct Distribution - Building...

85

Computational Fluid Dynamics Analysis of Flexible Duct Junction Box Design  

SciTech Connect (OSTI)

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.

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

2013-12-01T23:59:59.000Z

86

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

SciTech Connect (OSTI)

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.

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

87

Tips: Air Ducts | Department of Energy  

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

the walls, floors, and ceilings; it carries the air from your home's furnace and central air conditioner to each room. Ducts are made of sheet metal, fiberglass, or other...

88

INTERIOR DUCT SYSTEM DESIGN, CONSTRUCTION, AND PERFORMANCE  

SciTech Connect (OSTI)

By removing air distribution and conditioning equipment from unconditioned spaces, homeowners stand to benefit substantially with respect to both energy savings and indoor air quality. Duct leakage introduces: Greater heating and cooling loads from air at extreme temperatures and humidity levels; Outside air and air from unconditioned spaces that may contain air borne contaminants, combustion gases, pollen, mold spores, and/or particles of building materials; and Higher whole-house infiltration/exfiltration rates. Exemplary studies conducted since 1990 have demonstrated the prevalence of duct leakage throughout the United States and measured energy savings of approximately 20% during both heating and cooling seasons from leakage reduction. These all dealt with duct leakage to and/or from unconditioned spaces. In the building science community, leakage within the conditioned space is generally presumed to eliminate the negative consequences of duct leakage with the exception of possibly creating pressure imbalances in the house which relates to higher infiltration and/or exfiltration. The practical challenges of isolating ducts and air handlers from unconditioned spaces require builders to construct an air-tight environment for the ducts. Florida Solar Energy Center researchers worked with four builders in Texas, North Carolina, and Florida who build a furred-down chase located either in a central hallway or at the edges of rooms as an architectural detail. Some comparison homes with duct systems in attics and crawl spaces were included in the test group of more than 20 homes. Test data reveals that all of the duct/AHU systems built inside the conditioned space had lower duct leakage to unconditioned spaces than their conventional counterparts; however, none of the homes was completely free of duct leakage to unconditioned spaces. Common problems included wiring and plumbing penetrations of the chase, failure to treat the chase as an air tight space, and misguided fresh air inlet design. Improvements were implemented by the Texas builder and retested in July. Results showed a 36% reduction in duct leakage, significant enough to warrant the builder adopting the new sealing procedure.

Janet E.R. Mcllvaine; David Beal; Philip Fairey

2001-10-10T23:59:59.000Z

89

Numerical simulation of laminar flow in a curved duct  

SciTech Connect (OSTI)

This paper describes numerical simulations that were performed to study laminar flow through a square duct with a 900 bend. The purpose of this work was two fold. First, an improved understanding was desired of the flow physics involved in the generation of secondary vortical flows in three-dimensions. Second, adaptive gridding techniques for structured grids in three- dimensions were investigated for the purpose of determining their utility in low Reynolds number, incompressible flows. It was also of interest to validate the commercial computer code CFD-ACE. Velocity predictions for both non-adaptive and adaptive grids are compared with experimental data. Flow visualization was used to examine the characteristics of the flow though the curved duct in order to better understand the viscous flow physics of this problem. Generally, moderate agreement with the experimental data was found but shortcomings in the experiment were demonstrated. The adaptive grids did not produce the same level of accuracy as the non-adaptive grid with a factor of four more grid points.

Lopez, A.R.; Oberkampf, W.L.

1995-01-01T23:59:59.000Z

90

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

E-Print Network [OSTI]

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

Victoria, University of

91

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

E-Print Network [OSTI]

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

Pedersen, Tom

92

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

E-Print Network [OSTI]

improvement in 3 hydraulic diameters needed to achieve COVs below 10%. Without an air blender, the distance downstream of the T-junction for the COVs below 20% increased as the velocity of the sub duct airflow increased. About 95% of the cases achieved COVs...

Kim, Taehong

2012-06-07T23:59:59.000Z

93

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

SciTech Connect (OSTI)

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.

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

94

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

E-Print Network [OSTI]

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 ...

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

95

Imaging Molecular Gas in the Luminous Merger NGC 3256 : Detection of High-Velocity Gas and Twin Gas Peaks in the Double Nucleus  

E-Print Network [OSTI]

Molecular gas in the merging starburst galaxy NGC 3256 has been imaged with the Submillimeter Array at a resolution of 1'' x 2'' (170 x 340 pc at 35 Mpc). This is the first interferometric imaging of molecular gas in the most luminous galaxy within z=0.01. There is a large disk of molecular gas (r > 3 kpc) in the center of the merger with a strong gas concentration toward the double nucleus. The gas disk having a mass of ~3*10^9 Msun in the central 3 kpc rotates around a point between the two nuclei that are 850 pc apart on the sky. The molecular gas is warm and turbulent and shows spatial variation of the intensity ratio between CO isotopomers. High-velocity molecular gas is discovered at the galactic center. Its velocity in our line of sight is up to 420 km/s offset from the systemic velocity of the galaxy; the terminal velocity is twice as large as that due to the rotation of the main gas disk. The high-velocity gas is most likely due to a molecular outflow from the gas disk, entrained by the starburst-driven superwind in the galaxy. The molecular outflow is estimated to have a rate of ~10 Msun/yr and to play a significant role in the dispersal or depletion of molecular gas from the galactic center. A compact gas concentration and steep velocity gradient are also found around each of the twin nuclei. They are suggestive of a small gas disk rotating around each nucleus. If these are indeed mini-disks, their dynamical masses are ~10^9 Msun within a radius of 170 pc.

Kazushi Sakamoto; Paul T. P. Ho; Alison B. Peck

2006-03-03T23:59:59.000Z

96

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

E-Print Network [OSTI]

. 0 10. 0 14. 9 9-4 12. 0 VELOCITY FPM 1600 1460 1570 1300 TOTAL PRESSURE DROP IN. WATER 0 04 0. 10 0 02 o o8 o. o8 TABLE 3 21 PART III ALMQJATING CUHREYZ N. . GAME CALCULATOR APPLIED TO THE TOTAL PiiBSURE DROP METHOD GIVEN... resistance for Section B is then read to be 13. 3$ ohms which gives an R oi' 38 ' 2 ohms. From Figure 4 the velocity is found to be 1400 fpm and duct diameter 14. 9 inches. fhe voltage drop for Section D is read to be 10. 0 volts, giving a total head loss...

Howard, Charles Pinto

2012-06-07T23:59:59.000Z

97

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

SciTech Connect (OSTI)

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.

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

98

Tips: Air Ducts | Department of Energy  

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassiveSubmittedStatusButler Tina Butler Tina-Butler.jpg Tina L.Ducts Tips: Air Ducts

99

Potential Flow Calculations of Axisymmetric Ducted Wind Turbines  

E-Print Network [OSTI]

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

Widnall, Sheila

2009-09-02T23:59:59.000Z

100

Handover Performance of HVAC Duct Based Indoor Wireless Networks  

E-Print Network [OSTI]

Handover Performance of HVAC Duct Based Indoor Wireless Networks A. E. Xhafa, P. Sonthikorn, and O in indoor wireless net- works (IWN) that use heating, ventilation, and air conditioning (HVAC) ducts.e., new call blocking and handover dropping probabilities, of an IWN that uses HVAC ducts are up to 6

Stancil, Daniel D.

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101

Long Range Passive UHF RFID System Using HVAC Ducts  

E-Print Network [OSTI]

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

Hochberg, Michael

102

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

103

CALIFORNIA ENERGY Homeowners Benefits To Ducts In  

E-Print Network [OSTI]

efficiency is improved through the integrated design, construction, and operation of building systems of Small Commercial HVAC Systems Integrated Design of Commercial Building Ceiling Systems Integrated Design of the Integrated Design of Residential Ducting & Air Flow Systems research project. The reports are a result

104

Reducing Uncertainty for the DeltaQ Duct Leakage Test  

SciTech Connect (OSTI)

The thermal distribution system couples the HVAC components to the building envelope, and shares many properties of the buildings envelope including moisture, conduction and most especially air leakage performance. Duct leakage has a strong influence on air flow rates through building envelopes (usually resulting in much greater flows than those due to natural infiltration) because unbalanced duct air flows and leaks result in building pressurization and depressurization. As a tool to estimate this effect, the DeltaQ duct leakage test has been developed over the past several years as an improvement to existing duct pressurization tests. It focuses on measuring the air leakage flows to outside at operating conditions that are required for envelope infiltration impacts and energy loss calculations for duct systems. The DeltaQ test builds on the standard envelope tightness blower door measurement techniques by repeating the tests with the system air handler off and on. The DeltaQ test requires several assumptions to be made about duct leakage and its interaction with the duct system and building envelope in order to convert the blower door results into duct leakage at system operating conditions. This study examined improvements to the DeltaQ test that account for some of these assumptions using a duct system and building envelope in a test laboratory. The laboratory measurements used a purpose-built test chamber coupled to a duct system typical of forced air systems in US homes. Special duct leaks with controlled air-flow were designed and installed into an airtight duct system. This test apparatus allowed the systematic variation of the duct and envelope leakage and accurate measurement of the duct leakage flows for comparison to DeltaQ test results. This paper will discuss the laboratory test apparatus design, construction and operation, the various analysis techniques applied to the calculation procedure and present estimates of uncertainty in measured duct leakage.

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

2004-05-01T23:59:59.000Z

105

Velocity centroids as tracers of the turbulent velocity statistics  

E-Print Network [OSTI]

We use the results of magnetohydrodynamic (MHD) simulations to emulate spectroscopic observations and use maps of centroids to study their statistics. In order to assess under which circumstances the scaling properties of the velocity field can be retrieved from velocity centroids, we compare two point statistics (structure functions and power-spectra) of velocity centroids with those of the underlying velocity field and analytic predictions presented in a previous paper (Lazarian & Esquivel 2003). We tested a criterion for recovering velocity spectral index from velocity centroids derived in our previous work, and propose an approximation of the early criterion using only the variances of ``unnormalized'' velocity centroids and column density maps. It was found that both criteria are necessary, however not sufficient to determine if the centroids recover velocity statistics. Both criteria are well fulfilled for subsonic turbulence. We find that for supersonic turbulence with sonic Mach numbers > 2.5 centroids fail to trace the spectral index of velocity. Asymptotically, however, we claim that recovery of velocity statistics is always possible provided that the density spectrum is steep and the observed inertial range is sufficiently extended. In addition, we show that velocity centroids are useful for anisotropy studies and determining the direction of magnetic field, even if the turbulence is highly supersonic, but only if it is sub-Alfvenic. This provides a tool for mapping the magnetic field direction, and testing whether the turbulence is sub-Alfvenic or super-Alfvenic.

A. Esquivel; A. Lazarian

2005-05-28T23:59:59.000Z

106

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)

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.

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

2008-02-27T23:59:59.000Z

107

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

SciTech Connect (OSTI)

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.

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

2008-10-01T23:59:59.000Z

108

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

SciTech Connect (OSTI)

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.

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

109

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

E-Print Network [OSTI]

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...

Daniel, Steven Hall

1977-01-01T23:59:59.000Z

110

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...

111

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...

112

Aerodynamic design considerations for a free-flying ducted propeller  

SciTech Connect (OSTI)

The design philosophy for a free-flying vehicle powered by a ducted propeller is presented from an aerodynamic viewpoint. Airframe design concentrates on duct inlet lip curvature, diffuser angle, and methods of vehicle control. Wind tunnel test results are given to evaluate two inlet designs, two exit designs, and the effect of external appendages such as a camera pod or a forebody. Finally, a simple, analytic method of ducted propeller blade design is presented and the results compared with an existing ducted propeller blade. 14 refs., 28 figs., 2 tabs.

Weir, R.J.

1988-01-01T23:59:59.000Z

113

Leaf seal for transition duct in turbine system  

DOE Patents [OSTI]

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.

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

2013-06-11T23:59:59.000Z

114

Flexible metallic seal for transition duct in turbine system  

DOE Patents [OSTI]

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.

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

2014-04-22T23:59:59.000Z

115

Buried and Encapsulated Ducts - Building America Top Innovation...  

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

photo of worker blowing insulation on ducts in an attic. Ductwork installed in unconditioned attics can significantly increase the heating and cooling costs of homes, resulting in...

116

Evaluation of friction loss in flexible and galvanized duct  

E-Print Network [OSTI]

/d ratios ranging from 1 to 5. Statistical analysis of the data indicated that there was a difference in the equivalent length mean data and that the interaction between r/d ratio and duct size, r/d ratio and duct type, and duct type and duct size.... . . 51 APPENDIX F ADC STANDARD REPORTING FORMS ()E AND ()E(M). . . 55 APPENDIX G EQUATIONS UTILIZED TO CONVERT FRICTION LOSS DATA TO EQUIVALENT LENGTHS APPENDIX H 58 RESULTS FROM AIR FLOW VOLUME REPRODUCIBILITY TEST. APPENDIX I 61 DATA...

Zimmermann, Carlos Michael Alberto

1985-01-01T23:59:59.000Z

117

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

SciTech Connect (OSTI)

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.

Not Available

2013-11-01T23:59:59.000Z

118

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

E-Print Network [OSTI]

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...

Magri, Luca; Juniper, Matthew P.

2015-01-01T23:59:59.000Z

119

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

SciTech Connect (OSTI)

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.

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

120

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

SciTech Connect (OSTI)

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.

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

1991-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "duct high velocity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

NEW GUN CAPABILITY WITH INTERCHANGABLE BARRELS TO INVESTIGATE LOW VELOCITY IMPACT REGIMES AT THE LAWRENCE LIVERMORE NATIONAL LABORATORY HIGH EXPLOSIVES APPLICATIONS FACILITY  

SciTech Connect (OSTI)

A new gas gun capability is being activated at Lawrence Livermore National Laboratories located in the High Explosives Applications Facility (HEAF). The single stage light gas (dry air, nitrogen, or helium) gun has interchangeable barrels ranging from 25.4 mm to 76.2 mm in diameter with 1.8 meters in length and is being fabricated by Physics Applications, Inc. Because it is being used for safety studies involving explosives, the gun is planned for operation inside a large enclosed firing tank, with typical velocities planned in the range of 10-300 m/s. Three applications planned for this gun include: low velocity impact of detonator or detonator/booster assemblies with various projectile shapes, the Steven Impact test that involves impact initiation of a cased explosive target, and the Taylor impact test using a cylindrical explosive sample impacted onto a rigid anvil for fracture studies of energetic materials. A highlight of the gun features, outline on work in progress for implementing this capability, and discussion of the planned areas of research will be included.

Vandersall, K S; Behn, A; Gresshoff, M; Jr., L F; Chiao, P I

2009-09-16T23:59:59.000Z

122

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

E-Print Network [OSTI]

/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...

Hays, Charles C.

1986-01-01T23:59:59.000Z

123

Slow sound in lined flow ducts  

E-Print Network [OSTI]

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...

Auregan, Yves

2015-01-01T23:59:59.000Z

124

Compression effects on pressure loss in flexible HVAC ducts  

SciTech Connect (OSTI)

A study was conducted to evaluate the effect of compression on pressure drop in flexible, spiral wire helix core ducts used in residential and light commercial applications. Ducts of 6 inches, 8 inches and 10 inches (150, 200 and 250 mm) nominal diameters were tested under different compression configurations following ASHRAE Standard 120-1999--Methods of Testing to Determine Flow Resistance of HVAC Air Ducts and Fittings. The results showed that the available published references tend to underestimate the effects of compression. The study demonstrated that moderate compression in flexible ducts, typical of that often seen in field installations, could increase the pressure drop by a factor of four, while further compression could increase the pressure drop by factors close to ten. The results proved that the pressure drop correction factor for compressed ducts cannot be independent of the duct size, as suggested by ASHRAE Fundamentals, and therefore a new relationship was developed for better quantification of the pressure drop in flexible ducts. This study also suggests potential improvements to ASHRAE Standard 120-1999 and provides new data for duct design.

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

2002-07-01T23:59:59.000Z

125

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)

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.

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

126

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

SciTech Connect (OSTI)

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.

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

127

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

SciTech Connect (OSTI)

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.

Not Available

2014-01-01T23:59:59.000Z

128

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

E-Print Network [OSTI]

and noise generated by moving air. 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 1000 2000 3000 4000 5000 6000 7000 8000 Losses (" w.c. /100 ft) versus Air Velocity (FPM) Fig 1 Fig. 1: friction losses in a circular 6? duct in galva- nized....0 14.0 16.0 1000 2000 3000 4000 5000 6000 7000 8000 Losses?("?w.c.?/100?ft)?versus Air?Velocity?(FPM) ?Range of air velocities = 6500/3,800 = 1.86 ?Maximal practical speed 6,500 FPM ?Minimum transport velocity, for example 3,800 FPM...

Litomisky, A.

2010-01-01T23:59:59.000Z

129

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

SciTech Connect (OSTI)

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.

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

130

Development of a new duct leakage test: DeltaQ  

SciTech Connect (OSTI)

Duct leakage is a key factor in determining energy losses from forced air heating and cooling systems. Several studies (Francisco and Palmiter 1997 and 1999, Andrews et al. 1998, and Siegel et al. 2001) have shown that the duct system efficiency cannot be reliably determined without good estimates of duct leakage. Specifically, for energy calculations, it is the duct leakage air flow to outside at operating conditions that is required. Existing test methods either precisely measure the size of leaks (but not the flow through them at operating conditions), or measure these flows with insufficient accuracy. The DeltaQ duct leakage test method was developed to provide improved estimates of duct leakage during system operation. In this study we developed the analytical calculation methods and the test procedures used in the DeltaQ test. As part of the development process, we have estimated uncertainties in the test method (both analytically and based on field data) and designed automated test procedures to increase accuracy and reduce the contributions of operator errors in performing field tests. In addition, the test has been evaluated in over 100 houses by several research teams to show that it can be used in a wide range of houses and to aid in finding limits or problems in field applications. The test procedure is currently being considered by ASTM as an update of an existing duct leakage standard.

Walker,I.S.; Sherman,M.H.; Wempen, J.; Wang, D.; McWilliams, J.A.; Dickerhoff, D.J.

2001-08-01T23:59:59.000Z

131

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...

132

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

E-Print Network [OSTI]

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

Walker, Iain

2001-01-01T23:59:59.000Z

133

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

DOE Patents [OSTI]

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.

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

2010-12-14T23:59:59.000Z

134

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

E-Print Network [OSTI]

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

Massachusetts at Amherst, University of

135

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...

136

Improved Wireless Performance from Mode Scattering in Ventilation Ducts  

E-Print Network [OSTI]

as an in-building wireless infrastructure, prior work has developed an empirical model of the power loss duct systems. Specifically, they found that the power loss due to a signal that passes through multiple

Stancil, Daniel D.

137

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

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

America research program its and partners have worked out the kinks on a toolkit of duct design strategies. In this session you'll learn the pros and cons of these strategies so...

138

Building America Top Innovations Hall of Fame Profile ? Ducts...  

Energy Savers [EERE]

being adopted by builders across the country. Far too many homes are constructed with HVAC equipment and ductwork located in a vented crawlspace or a vented attic. Moving ducts...

139

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

140

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]

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...

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

Note: This page contains sample records for the topic "duct high velocity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

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

DOE Patents [OSTI]

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.

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

1999-01-01T23:59:59.000Z

142

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

DOE Patents [OSTI]

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.

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

1999-07-13T23:59:59.000Z

143

BETTER DUCT SYSTEMS FOR HOME HEATING AND COOLING.  

SciTech Connect (OSTI)

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.

ANDREWS,J.

2001-01-01T23:59:59.000Z

144

WAVE PROPAGATION in the HOT DUCT of VHTR  

SciTech Connect (OSTI)

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.

Richard Schultz; Jim C. P. Liou

2013-07-01T23:59:59.000Z

145

Measure Guideline: Buried and/or Encapsulated Ducts  

SciTech Connect (OSTI)

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.

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

2013-08-01T23:59:59.000Z

146

Integrating ducts into the conditioned space: Successes and challenges  

SciTech Connect (OSTI)

In residential and light commercial construction in the United States, heating and cooling ducts are often located outside the thermal or pressure boundary of the conditioned space. This location is selected for aesthetic and space requirement reasons. Typical duct locations include attics, above dropped ceilings, crawlspaces, and attached garages. A wide body of literature has found that distribution system conduction and air leakage can cause 30-40% energy losses before cooling and heating air reaches the conditioned space. Recent innovative attempts at locating ducts in the conditioned space have had mixed results in terms of improving duct efficiency. Some of these strategies include cathedralizing attics (sealing and insulating at the attic roofline) and locating ducts in interstitial spaces. This paper reviews modeling studies that suggest substantial savings could be realized from these strategies and presents field measurements which reveal that construction planning and execution errors can prevent these strategies from being widely applied or from being effective when they are applied. These types of problems will need to be overcome for effective integration of ducts into the conditioned space.

Siegel, Jeffrey; Walker, Iain

2004-05-01T23:59:59.000Z

147

Hot-film anemometer measurements in adiabatic two-phase flow through a vertical duct  

SciTech Connect (OSTI)

A hot-film anemometer (HFA) probe was used to obtain local measurements of void fraction and bubble frequency in a vertically oriented, high aspect ratio duct containing R-134a under selected adiabatic two-phase flow conditions. Data were obtained along a narrow dimension scan over the range 0.03 {le} {bar Z} {le} 0.80, where {bar Z} is the distance from the wall normalized with the duct spacing dimension. The void fraction profiles displayed large gradients in the near-wall regions and broad maxima near the duct centerline. The trends in the bubble frequency data generally follow those for the local void fraction data. However, the relatively large number of bubbles at higher pressure implies a larger magnitude of the interfacial area concentration, for the same cross-sectional average void fraction. For the two annular flow conditions tested, analysis of the HFA output voltage signal enabled identification of three distinct regions of the flow field; liquid film with dispersed bubbles, interfacial waves, and continuous vapor with dispersed droplets.

Trabold, T.A.; Moore, W.E.; Morris, W.O. [Lockheed Martin Corp., Schenectady, NY (United States)

1997-06-01T23:59:59.000Z

148

Unitaxial constant velocity microactuator  

DOE Patents [OSTI]

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.

McIntyre, T.J.

1994-06-07T23:59:59.000Z

149

Measure Guideline: Optimizing the Configuration of Flexible Duct Junction Boxes  

SciTech Connect (OSTI)

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.

Beach, R.; Burdick, A.

2014-03-01T23:59:59.000Z

150

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

SciTech Connect (OSTI)

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.

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

2012-01-01T23:59:59.000Z

151

Bundle duct interaction studies for fuel assemblies. [LMFBR  

SciTech Connect (OSTI)

It is known that the wire-wrapped rods and duct in an LMFBR are undergoing a gradual structural distortion from the initially uniform geometry under the combined effects of thermal expansion and irradiation induced swelling and creep. These deformations have a significant effect on flow characteristics, thus causing changes in thermal behavior such as cladding temperature and temperature distribution within a bundle. The temperature distribution may further enhance or retard irradiation induced deformation of the bundle. This report summarizes the results of the continuing effort in investigating the bundle-duct interaction, focusing on the need for the large development plant.

Hsia, H.T.S.; Kaplan, S.

1981-06-01T23:59:59.000Z

152

Advanced Strategy Guideline: Air Distribution Basics and Duct Design  

SciTech Connect (OSTI)

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.

Burdick, A.

2011-12-01T23:59:59.000Z

153

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

E-Print Network [OSTI]

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...

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

2002-01-01T23:59:59.000Z

154

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

E-Print Network [OSTI]

. 94720 This work was supported by the Assistant Secretary for Energy Efficiency and Renewable Energy......................................................... 5 Figure 4. New plastic flexible ducts in an attic.......................................................................... 6 Figure 5. Combination of plastic insulated flexible duct and added open face glass fiber

155

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

SciTech Connect (OSTI)

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.

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

2011-11-01T23:59:59.000Z

156

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

E-Print Network [OSTI]

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...

Weaver, K.; Culp, C.

2006-01-01T23:59:59.000Z

157

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

E-Print Network [OSTI]

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...

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

2003-01-01T23:59:59.000Z

158

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

E-Print Network [OSTI]

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

Stancil, Daniel D.

159

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

DOE Patents [OSTI]

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.

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

2002-01-01T23:59:59.000Z

160

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

Note: This page contains sample records for the topic "duct high velocity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Duct Thermal Performance Models for Large Commercial Buildings  

E-Print Network [OSTI]

Energy Technologies Division Indoor Environment Department Lawrence Berkeley National Laboratory Berkeley Secretary for Energy Efficiency and Renewable Energy, Building Technologies Program, of the U.S. Department) for his assistance in defining the duct surface heat transfer models described in the body of this report

162

CALIFORNIA ENERGY Residential Duct Placement Field Test and  

E-Print Network [OSTI]

efficiency is improved through the integrated design, construction, and operation of building systems of Small Commercial HVAC Systems Integrated Design of Commercial Building Ceiling Systems Integrated Design of the Integrated Design of Residential Ducting & Air Flow Systems research project. The reports are a result

163

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

SciTech Connect (OSTI)

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.

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

1996-01-01T23:59:59.000Z

164

Building America Top Innovations 2013 Profile ? High-Performance...  

Energy Savers [EERE]

in Federal rulemaking procedures. This work also documented the high duct system static pressure problem endemic to the majority of residential HVAC systems. It has led to...

165

Velocity pump reaction turbine  

DOE Patents [OSTI]

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.

House, Palmer A. (Walnut Creek, CA)

1982-01-01T23:59:59.000Z

166

Velocity pump reaction turbine  

DOE Patents [OSTI]

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.

House, Palmer A. (Walnut Creek, CA)

1984-01-01T23:59:59.000Z

167

LABORATORY EVALUATION OF THE DELTA Q TEST FOR DUCT LEAKAGE  

SciTech Connect (OSTI)

Using a residential-size duct system in a controlled laboratory setting, the repeatability and accuracy of the Delta Q test for air leakage in residential duct systems have been measured. More than 100 Delta Q tests were performed. These were compared with results using fan pressurization and also with results of a procedure (Delta Q Plus) that uses leakage hole-size information to select the leakage pressures to be used in the Delta Q algorithm. The average error in supply or return leakage for the fan-pressurization test was 6.4% of system fan flow. For the Delta Q test it was 3.4% of fan flow, while for Delta Q Plus it was 1.9% of fan flow.

ANDREWS,J.W.

2003-05-01T23:59:59.000Z

168

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

SciTech Connect (OSTI)

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.

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

1986-08-01T23:59:59.000Z

169

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

170

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

E-Print Network [OSTI]

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

Ferreira, Paulo J.

171

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

E-Print Network [OSTI]

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...

Ugursal, A.; Culp, C.

2006-01-01T23:59:59.000Z

172

E-Print Network 3.0 - amplatzer duct occluder Sample Search Results  

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

School of Engineering and Applied Sciences, Harvard University Collection: Engineering 33 VIRTUAL ENVIRONMENTS FOR TRAINING CRITICAL SKILLS IN LAPAROSCOPIC SURGERY Summary: duct...

173

E-Print Network 3.0 - assembly duct irradiated Sample Search...  

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

The "perfect... 71100-draft copy: do not quote 1 of 30 New Technologies for Residential HVAC Ducts Burke Treidler... February 1995 Executive Summary There are many problems with...

174

E-Print Network 3.0 - acoustic duct system Sample Search Results  

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

Mitigation of Acoustic Resonance using Electrically Shunted Loudspeakers Summary: and resistor. Experimental application to a closed acoustic duct results in 14 dB pressure...

175

E-Print Network 3.0 - acoustic ducts Sample Search Results  

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

Mitigation of Acoustic Resonance using Electrically Shunted Loudspeakers Summary: and resistor. Experimental application to a closed acoustic duct results in 14 dB pressure...

176

Economizer Applications in Dual-Duct Air-Handling Units  

E-Print Network [OSTI]

.E.R.O. These homes were constructed by over a dozen different builders. In this paper data from 310 of these homes is presented. These homes have featured better envelopes and windows, interior and/or duct systems with adequate returns, fan integrated positive....1 Maximum HERS 90.3 89.9 Figure 5 HERS Scores for FL H.E.R.O. Homes SF MF Sample Size, n 164 146 Average ACH50 4.5 5.2 Median ACH50 4.4 5.3 Minimum ACH50 2.1 2.2 Maximum ACH50 8.6 8...

Joo, I.; Liu, M.

2002-01-01T23:59:59.000Z

177

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

E-Print Network [OSTI]

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 ?...

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

2014-07-11T23:59:59.000Z

178

Statistics of Velocity from Spectral Data: Modified Velocity Centroids  

E-Print Network [OSTI]

We address the problem of studying interstellar turbulence using spectral line data. We find a criterion when the velocity centroids may provide trustworthy velocity statistics. To enhance the scope of centroids applications, we construct a measure that we term ``modified velocity centroids'' (MVCs) and derive an analytical solution that relates the 2D spectra of the modified centroids with the underlying 3D velocity spectrum. We test our results using synthetic maps constructed with data obtained through simulations of compressible magnetohydrodynamical (MHD) turbulence. We show that the modified velocity centroids (MVCs) are complementary to the the Velocity Channel Analysis (VCA) technique. Employed together, they make determining of the velocity spectral index more reliable and for wider variety of astrophysical situations.

A. Lazarian; A. Esquivel

2003-06-10T23:59:59.000Z

179

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

E-Print Network [OSTI]

This study was conducted to determine the effects of compression on pressure drops in non-metallic flexible duct. Duct sizes of 12”, 14” and 16” diameters were tested at a five different compression ratios (maximum stretch, 4%, 15%, 30% and 45...

Cantrill, David Lee

2013-08-01T23:59:59.000Z

180

A Laboratory Method For Measuring The Ozone Emission From In-duct Air Cleaners.  

E-Print Network [OSTI]

: Emission rate, HVAC air cleaners, electrostatic precipitators, coronas, standard test method 1 Introduction Subchapter 8.7). However, in-duct air cleaners including electronic air cleaners, electrostatic precipitators of an ozone analyzer. Viner et al. (1992) studied commercial in-duct electrostatic precipitators and observed

Siegel, Jeffrey

Note: This page contains sample records for the topic "duct high velocity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

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

E-Print Network [OSTI]

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

Alonso, Juan J.

182

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

E-Print Network [OSTI]

.Hourlyairflowrequirements, part-load fan characteristics, and duct static pressure control are incorporated into the problem airflow. Fan power is also influ- enced if static pressure at the end of the longest duct line for effective, energy-efficient, and comfortable heating, ventilat- ing, and air-conditioning (HVAC) systems

183

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

184

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

E-Print Network [OSTI]

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

Stancil, Daniel D.

185

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

E-Print Network [OSTI]

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

Stancil, Daniel D.

186

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

E-Print Network [OSTI]

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

Pedersen, Tom

187

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

E-Print Network [OSTI]

LBNL# 40102 Field Investigation of Duct System Performance in California Light Commercial Buildings 1 of 26 Field Investigation of Duct System Performance in California Light Commercial Buildings Wm performance in fifteen systems located in eight northern California buildings. Abstract Light commercial

188

Beat phenomenon at the arrival of a guided mode in a semi-infinite acoustic duct  

E-Print Network [OSTI]

. This eigen value problem has an infinite discrete number of solutions N (x, y) with the modal wave numbers NBeat phenomenon at the arrival of a guided mode in a semi-infinite acoustic duct P. Gatignola , M at an initial time in the terminal section of a semi-infinite acoustic duct, will undergo dispersion effects

Paris-Sud XI, Université de

189

Longevity of Duct Tape in Residential Air Distribution Systems: 1-D, 2-D, and 3-D Joints  

E-Print Network [OSTI]

This paper addresses the effectiveness of using duct tape in sealing residential air distribution systems through two laboratory longevity tests. The first test involved the aging of common “core-to-collar joints” of flexible duct to sheet metal...

Abushakra, B.

2003-01-01T23:59:59.000Z

190

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

E-Print Network [OSTI]

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

Abdou, Mohamed

191

Turbulence Spectra from Spectral Lines: Tests of the Velocity Channel Analysis and Velocity Coordinate Spectrum Techniques  

E-Print Network [OSTI]

Turbulence is a key element of the dynamics of astrophysical fluids, including those of interstellar medium, clusters of galaxies and circumstellar regions. Turbulent motions induce Doppler shifts of observable emission and absorption lines and this motivates studies of turbulence using precision spectroscopy. We provide high resolution numerical testing of the two promising techniques, namely, Velocity Channel Analysis and Velocity Coordinate Spectrum. We obtain an expression for the shot noise that the discretization of the numerical data entails and successfully test it. We show that numerical resolution required for recovering the underlying turbulent spectrum from observations depend on the spectral index of velocity fluctuations. Thus the low resolution testing may be misleading.

A. Chepurnov; A. Lazarian

2007-01-31T23:59:59.000Z

192

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

E-Print Network [OSTI]

( Eq. 1 )))(1()1( ))(1( 60 ( , , sambspsprrpr inrambr ine cap cap ines cooling ttBCtBCa hhaQ E E QaDE ??+??+ ??+= ? ? Eq. 2 where, Bs = conduction efficiency of supply duct = )) 60 exp( spine s RCQ A... ? ? , Eq. 3 Br = conduction efficiency of return duct = )) 60 exp( rpine r RCQ A ? ? , Eq. 4 as = air leakage efficiency of the duct of supply duct = ( e se Q QQ ? ), Eq. 5...

Haberl, J.S.; Kim, S.

2010-01-01T23:59:59.000Z

193

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

E-Print Network [OSTI]

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

Abdou, Mohamed

194

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

E-Print Network [OSTI]

7/11/00-draft copy: do not quote 1 of 30 New Technologies for Residential HVAC Ducts Burke Treidler is not evaluated and HVAC contractors overcome duct system shortcomings by installing oversized equipment Technologies for Residential HVAC Ducts fittings with some use of ductboard. Fittings that snap together were

195

Apparatus and method for laser velocity interferometry  

DOE Patents [OSTI]

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.

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

196

Duct leakage impacts on VAV system performance in California large commercial buildings  

SciTech Connect (OSTI)

The purpose of this study is to evaluate the variability of duct leakage impacts on air distribution system performance for typical large commercial buildings in California. Specifically, a hybrid DOE-2/TRNSYS sequential simulation approach was used to model the energy use of a low-pressure terminal-reheat variable-air-volume (VAV) HVAC system with six duct leakage configurations (tight to leaky) in nine prototypical large office buildings (representing three construction eras in three California climates where these types of buildings are common). Combined fan power for the variable-speed-controlled supply and return fans at design conditions was assumed to be 0.8 W/cfm. Based on our analyses of the 54 simulation cases, the increase in annual fan energy is estimated to be 40 to 50% for a system with a total leakage of 19% at design conditions compared to a tight system with 5% leakage. Annual cooling plant energy also increases by about 7 to 10%, but reheat energy decreases (about 3 to 10%). In combination, the increase in total annual HVAC site energy is 2 to 14%. The total HVAC site energy use includes supply and return fan electricity consumption, chiller and cooling tower electricity consumption, boiler electricity consumption, and boiler natural gas consumption. Using year 2000 average commercial sector energy prices for California ($0.0986/kWh and $7.71/Million Btu), the energy increases result in 9 to 18% ($7,400 to $9,500) increases in HVAC system annual operating costs. Normalized by duct surface area, the increases in annual operating costs are 0.14 to 0.18 $/ft{sup 2}. Using a suggested one-time duct sealing cost of $0.20 per square foot of duct surface area, these results indicate that sealing leaky ducts in VAV systems has a simple payback period of about 1.3 years. Even with total leakage rates as low as 10%, duct sealing is still cost effective. This suggests that duct sealing should be considered at least for VAV systems with 10% or more total duct leakage. The VAV system that we simulated had perfectly insulated ducts, and maintained constant static pressure in the ducts upstream of the VAV boxes and a constant supply air temperature at the airhandler. Further evaluations of duct leakage impacts should be carried out in the future after methodologies are developed to deal with duct surface heat transfer effects, to deal with airflows entering VAV boxes from ceiling return plenums (e.g., to model parallel fan-powered VAV boxes), and to deal with static pressure reset and supply air temperature reset strategies.

Wray, Craig P.; Matson, Nance E.

2003-10-01T23:59:59.000Z

197

Device for temporarily closing duct-formers in well completion apparatus  

SciTech Connect (OSTI)

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.

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

1981-08-25T23:59:59.000Z

198

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

E-Print Network [OSTI]

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...

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

199

Note: A helical velocity selector for continuous molecular beams  

SciTech Connect (OSTI)

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.

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

200

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

E-Print Network [OSTI]

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

Sever, David M.

Note: This page contains sample records for the topic "duct high velocity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

E-Print Network 3.0 - air heater duct Sample Search Results  

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

15542 Fuel-Fired Radiant Heaters - RESERVED 15543 Fuel-Fired Unit Heaters... Electric Heating Cables -RESERVED 15785 Air-to-Air Energy Recovery Units - RESERVED 15815 Metal Ducts...

202

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

E-Print Network [OSTI]

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 ...

widnall, sheila

2014-06-30T23:59:59.000Z

203

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

E-Print Network [OSTI]

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...

Ugursal, A.; Culp, C.H.

204

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

E-Print Network [OSTI]

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...

Fan, Wenshu

2009-05-15T23:59:59.000Z

205

GMTI radar minimum detectable velocity.  

SciTech Connect (OSTI)

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.

Richards, John Alfred

2011-04-01T23:59:59.000Z

206

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

SciTech Connect (OSTI)

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.

Not Available

2014-09-01T23:59:59.000Z

207

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

E-Print Network [OSTI]

622 ©2009 ASHRAE This paper is based on findings resulting from ASHRAE Research Project RP-1333. ABSTRACT A study was conducted to measure air pressure loss in non- metallic flexible ducts and included 12” (305 mm), 14” (356 mm) and 16” (406 mm...) diameter ducts on a flat surface and also positioned over joists on 24” (610 mm) centers. For this study, flexible duct compression configurations were fully stretched and 4%, 15%, 30% and 45% compressed. Measure- ments were performed at each compression...

Culp, C.H.; Cantrill, D.

208

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

E-Print Network [OSTI]

the impact of static pressure reset on HVAC system thermalHVAC control system varies the supply fan airflow to maintain a constant duct static pressure

Wray, Craig

2010-01-01T23:59:59.000Z

209

Velocity requirements for causality violation  

E-Print Network [OSTI]

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.

Giovanni Modanese

2015-01-18T23:59:59.000Z

210

Determination of hydrogen cluster velocities and comparison with numerical calculations  

SciTech Connect (OSTI)

The use of powerful hydrogen cluster jet targets in storage ring experiments led to the need of precise data on the mean cluster velocity as function of the stagnation temperature and pressure for the determination of the volume density of the target beams. For this purpose a large data set of hydrogen cluster velocity distributions and mean velocities was measured at a high density hydrogen cluster jet target using a trumpet shaped nozzle. The measurements have been performed at pressures above and below the critical pressure and for a broad range of temperatures relevant for target operation, e.g., at storage ring experiments. The used experimental method is described which allows for the velocity measurement of single clusters using a time-of-flight technique. Since this method is rather time-consuming and these measurements are typically interfering negatively with storage ring experiments, a method for a precise calculation of these mean velocities was needed. For this, the determined mean cluster velocities are compared with model calculations based on an isentropic one-dimensional van der Waals gas. Based on the obtained data and the presented numerical calculations, a new method has been developed which allows to predict the mean cluster velocities with an accuracy of about 5%. For this two cut-off parameters defining positions inside the nozzle are introduced, which can be determined for a given nozzle by only two velocity measurements.

Täschner, A.; Köhler, E.; Ortjohann, H.-W.; Khoukaz, A. [Institut für Kernphysik, Westfälische Wilhelms-Universität Münster, D-48149 Münster (Germany)] [Institut für Kernphysik, Westfälische Wilhelms-Universität Münster, D-48149 Münster (Germany)

2013-12-21T23:59:59.000Z

211

Cavitation erosion in blocked flow with a ducted ice-class propeller  

SciTech Connect (OSTI)

Ships that operate in ice often encounter momentary increased propeller cavitation because ice pieces block the flow into the propeller. For ducted propellers, this additional cavitation is more significant than it is for open propellers; ice pieces may become lodged against and within the duct and subject the propeller to longer periods of increased cavitation due to the blocked flow. Associated with this blocked flow is the possibility of cavitation erosion on the propeller. An erosion study, using paint films, was conducted in a cavitation tunnel with a model propeller of the type fitted to the Canadian Marine Drilling Ltd. vessel MV Robert LeMeur. A simulated ice blockage was installed ahead of the propeller model and within the duct. Tests were carried out over a range of advance coefficients for various test conditions. The resulting types of cavitation were documented, the erosion patterns were photographed and comparisons between each test were made.

Doucet, J.M.; Bose, N.; Walker, D. [Memorial Univ. of Newfoundland, St. John`s, Newfoundland (Canada). Ocean Engineering Research Centre; Jones, S.J. [National Research Council of Canada, St. John`s, Newfoundland (Canada). Inst. for Marine Dynamics

1996-12-31T23:59:59.000Z

212

Nuclear reactor fuel assembly duct-tube-to-inlet-nozzle attachment system  

DOE Patents [OSTI]

A reusable system for removably attaching the lower end 21 of a nuclear reactor fuel assembly duct tube to an upper end 11 of a nuclear reactor fuel assembly inlet nozzle. The duct tube's lower end 21 has sides terminating in locking tabs 22 which end in inwardly-extending flanges 23. The flanges 23 engage recesses 13 in the top section 12 of the inlet nozzle's upper end 11. A retaining collar 30 slides over the inlet nozzle's upper end 11 to restrain the flanges 23 in the recesses 13. A locking nut 40 has an inside threaded portion 41 which engages an outside threaded portion 15 of the inlet nozzle's upper end 11 to secure the retaining collar 30 against protrusions 24 on the duct tube's sides.

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

1982-01-01T23:59:59.000Z

213

Velocity Distributions from Nonextensive Thermodynamics  

E-Print Network [OSTI]

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)

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

2006-10-05T23:59:59.000Z

214

CO and IRAS detection of an intermediate-velocity cloud  

SciTech Connect (OSTI)

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.

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

215

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

216

One Component Two Phase Flow in Horizontal and Vertical Ducts: Some Basic Considerations  

SciTech Connect (OSTI)

For a description and analysis of the flow they consider the conservation equations of the two phases separately, but in thermal and mechanical equilibrium, coupled by the itnerface shear forces (two fluid model, drift flux model). Coupling may be weak or strong, depending on Froude and Mach numbers of the flow. The fluid is highly compressible, not because the individual phases move at such speeds that their individual density changes are significant but because evapiration (phase change) results in large density changes of the system at moderate pressure or temperature changes once flashing occurs. The slip between the phases is caused by unequal wall shear stress, acceleration of the fluid or gravitational forces and is hindered by the interface interaction. if they denote by {gamma} the ratio of the liquid density to the vapor density and by {sigma} the ratio of the vapor speed to the liquid speed they find that in horizontal flows {sigma} = {gamma}{sup 1/2} yields the maximum slip (neglecting acceleration effects) that can be reached with no interface force acting (assuming equal friction coefficients for both phases at the wall). If one investigates the conditions of thermodynamic flow similarity between different substances in two phase flow, one finds that the latent heat of vaporization is the principal controlling parameter. Thus, a 5 cm diameter test section in two phase R-114, at room temperature, corresponds to a 30 cm diameter duct in water-steam at boiling conditions at high temperatures such as encountered in geothermal and other power production systems.

Maeder, Paul F.; Dickinson, David A.; Nikitopoulos, Dimitris E.

1983-12-15T23:59:59.000Z

217

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

SciTech Connect (OSTI)

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.

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

218

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

SciTech Connect (OSTI)

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.

Andrews, J.W.

1995-08-01T23:59:59.000Z

219

ERROR REDUCTION IN DUCT LEAKAGE TESTING THROUGH DATA CROSS-CHECKS  

SciTech Connect (OSTI)

One way to reduce uncertainty in scientific measurement is to devise a protocol in which more quantities are measured than are absolutely required, so that the result is over constrained. This report develops a method for so combining data from two different tests for air leakage in residential duct systems. An algorithm, which depends on the uncertainty estimates for the measured quantities, optimizes the use of the excess data. In many cases it can significantly reduce the error bar on at least one of the two measured duct leakage rates (supply or return), and it provides a rational method of reconciling any conflicting results from the two leakage tests.

ANDREWS, J.W.

1998-12-31T23:59:59.000Z

220

Nucleonic analysis of a preliminary design for the ETF neutral-beam-injector duct shielding  

SciTech Connect (OSTI)

A nucleonic analysis of the Engineering Test Facility Neutral-Beam-Injector duct shielding 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 a subsequent discrete-ordinates calculation of the neutron and gamma-ray transport through the shield. The analysis also included determination of the energy and angular distribution of neutrons and gamma rays entering the duct from the torus plasma chamber. Confidence in the hybrid method and the results obtained were provided through a comparison with three-dimensional Monte Carlo results.

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

1980-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "duct high velocity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

RCUT: A Non-Invasive Method for Detection, Location, and Quantification of Radiological Contaminants in Pipes and Ducts - 12514  

SciTech Connect (OSTI)

Radiological Characterization Using Tracers (RCUT) is a minimally invasive method for detection and location of residual radiological contamination in pipes and ducts. The RCUT technology utilizes reactive gaseous tracers that dissociate when exposed to gamma and/or beta radiation emitting from a radiological contaminant in a pipe or duct. Sulfur hexafluoride (SF{sub 6}) was selected as a tracer for this radiological application, because it is a chemically inert gas that is both nonflammable, nontoxic, and breaks down when exposed to gamma radiation. Laboratory tests demonstrated that the tracer pair of SF{sub 6} and O{sub 2} formed SO{sub 2}F{sub 2} when exposed to a gamma or beta radioactive field, which indicated the presence of radiological contamination. Field application of RCUT involves first injecting the reactive tracers into the pipe to fill the pipe being inspected and allowing sufficient time for the tracer to interact with any contaminants present. This is followed by the injection of an inert gas at one end of the pipe to push the reactive tracer at a known or constant flow velocity along the pipe and then out the exit and sampling port at the end of the pipeline where its concentration is measured by a gas chromatograph. If a radiological contaminant is present in the pipe being tested, the presence of SO{sub 2}F{sub 2} will be detected. The time of arrival of the SO{sub 2}F{sub 2} can be used to locate the contaminant. If the pipe is free of radiological contamination, no SO{sub 2}F{sub 2} will be detected. RCUT and PCUT are both effective technologies that can be used to detect contamination within pipelines without the need for mechanical or human inspection. These methods can be used to detect, locate, and/or estimate the volume of a variety of radioactive materials and hazardous chemicals such as chlorinated solvents, petroleum products, and heavy metals. While further optimization is needed for RCUT, the key first step of identification of a tracer compound appropriate for the application of detecting radioactive pipeline contamination through the detection of decomposition products of SF{sub 6} has been demonstrated. Other tracer gases that will also undergo radiolysis will be considered in the future. The next step for the RCUT development process is conducting laboratory scale tests using short pipelines to define analytical requirements, establish performance boundaries, and develop strategies for lower exposure levels. Studies to identify additional analytical techniques using equipment that is more field rugged than a GC/MS would also be beneficial. (authors)

Bratton, Wesley L.; Maresca, Joseph W. Jr.; Beck, Deborah A. [Vista Engineering Technologies, L.L.C., Richland, WA, 99352 (United States)

2012-07-01T23:59:59.000Z

222

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

E-Print Network [OSTI]

of the HVAC Duct as a Communication Channel Pavel V. Nikitin, Member, IEEE, Daniel D. Stancil, Senior Member (HVAC) ducts in buildings behave as multimode waveguides when excited at radio frequencies and thus, can of a usual indoor propagation channel. In this paper, we describe physical mechanisms which affect the HVAC

Hochberg, Michael

223

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

E-Print Network [OSTI]

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

Eindhoven, Technische Universiteit

224

Turbulence Spectra from Doppler-broadened Spectral Lines: Tests of the Velocity Channel Analysis and Velocity Coordinate Spectrum Techniques  

E-Print Network [OSTI]

Turbulent motions induce Doppler shifts of observable emission and absorption lines motivating studies of turbulence using precision spectroscopy. We provide the numerical testing of the two most promising techniques, Velocity Channel Analysis (VCA) and Velocity Coordinate Spectrum (VCS). We obtain an expression for the shot noise that the discretization of the numerical data entails and successfully test it. We show that the numerical resolution required for recovering the underlying turbulent spectrum from observations depend on the spectral index of velocity fluctuations, which makes low resolution testing misleading. We demonstrate numerically that, dealing with absorption lines, sampling of turbulence along just a dozen directions provides a high quality spectrum with the VCS technique.

A. Chrupnov; A. Lazarian

2008-11-07T23:59:59.000Z

225

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]

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

Stancil, Daniel D.

226

BENCAP, LLC: CAPSULE VELOCITY TEST  

SciTech Connect (OSTI)

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.

Meidinger, Brian

2005-09-07T23:59:59.000Z

227

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

SciTech Connect (OSTI)

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.

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

1989-11-01T23:59:59.000Z

228

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

E-Print Network [OSTI]

, ) 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

Paris-Sud XI, Université de

229

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

SciTech Connect (OSTI)

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.

Rudd, A.; Prahl, D.

2014-12-01T23:59:59.000Z

230

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

DOE Patents [OSTI]

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.

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

2013-04-02T23:59:59.000Z

231

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

E-Print Network [OSTI]

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...

Kim, S.; Haberl, J.

232

A COMPUTATIONAL AND EXPERIMENTAL ANALYSIS OF A DUCTED FAN USED IN VTOL UAV SYSTEMS  

E-Print Network [OSTI]

conditions. Fan rotor field including secondary flows, tip vortices, blade boundary layers and the wake sys wind tunnel test data. Total pressure measurements and computational predictions of mean flow field shows a significant level of 3D hub separation affecting the overall performance of the ducted fan

Camci, Cengiz

233

Toward a Better Understanding of Ducted Rotor Antitorque and Directional Control in Forward Flight  

E-Print Network [OSTI]

of the Core Automatic Flight Control System (CAFCS) mode. Figure 1 shows a sustained, large-amplitude 1-Hz yaw ABSTRACT Despite decades of very successful yaw-control and anti-torque applications, the aerodynamics dramatic. From a handling-qualities perspective, the ducted rotor provides the loads capacity required

234

Control of Flow Separation in S-ducts via Flow Injection and Suction  

E-Print Network [OSTI]

with minimum stagnation pressure losses at the compressor face. In some aircraft a straight inletT 1 Research of the curvature of the S-duct centerline lead to cross-stream centrifugal pressure gradients which cause distribution on the engine compressor face. The net effect of the secondary flow and of the diffuser adverse

Debiasi, Marco

235

Cooling air duct and screen arrangement for an air cooled engine  

SciTech Connect (OSTI)

This patent describes a cooling air duct and screen arrangement for an air cooled engine which includes an improved cooling air system for ensuring a supply of relatively clean air for ingestion by the cooling shroud, which consists of: a vertical transverse baffle mounted to the frame and fitting closely against a forward top portion of the shroud and having an edge shaped complementary to and disposed at least closely adjacent the hood. An air duct is mounted to the frame and has an upright rear wall seated against the front of the shroud in an area surrounding the inlet. The air duct further has an upright front wall and a connecting wall joining respective side and bottom edges of the front and rear walls and cooperating therewith to define an upwardly facing opening. A screen is located forwardly of the baffle and has a top and front joined by opposite sides with the top and opposite sides having rear edges mounted against the baffle and with the opposite sides and front having bottom edges engaged with the air duct about the upwardly facing opening wherein the screen is mounted solely to the baffle by connection means including a vertical guide means provided on the forward side of the baffle and flange means formed on the screen and being vertically slidably received in the guide means.

Hoch, J.J.; Stricker, D.K.

1986-03-04T23:59:59.000Z

236

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

E-Print Network [OSTI]

and mitigation methods of voided ducts in PT structures. Although controversy exists on how to best protect PT tendons from corrosion, filling these voids with grout may be one option. An optimized grouting procedure for repairing these voids is needed how best...

Im, Seok Been

2011-02-22T23:59:59.000Z

237

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

E-Print Network [OSTI]

diagnostic tools for detecting and locating leaks in the air distribution system. The tracer gas tests described are a good complement to these tools in the detection, location, and measurement of duct leakage. Testing for house infiltration once with the air...

Cummings, J. B.

1989-01-01T23:59:59.000Z

238

Field Test of Advanced Duct-Sealing Technologies Within the Weatherization Assistance Program  

SciTech Connect (OSTI)

A field test of an aerosol-spray duct-sealing technology and a conventional, best-practice approach was performed in 80 homes to determine the efficacy and programmatic needs of the duct-sealing technologies as applied in the U.S. Department of Energy Weatherization Assistance Program. The field test was performed in five states: Iowa, Virginia, Washington, West Virginia, and Wyoming. The study found that, compared with the best-practice approach, the aerosol-spray technology is 50% more effective at sealing duct leaks and can potentially reduce labor time and costs for duct sealing by 70%, or almost 4 crew-hours. Further study to encourage and promote use of the aerosol-spray technology within the Weatherization Assistance Program is recommended. A pilot test of full production weatherization programs using the aerosol-spray technology is recommended to develop approaches for integrating this technology with other energy conservation measures and minimizing impacts on weatherization agency logistics. In order to allow or improve adoption of the aerosol spray technology within the Weatherization Assistance Program, issues must be addressed concerning equipment costs, use of the technology under franchise arrangements with Aeroseal, Inc. (the holders of an exclusive license to use this technology), software used to control the equipment, safety, and training. Application testing of the aerosol-spray technology in mobile homes is also recommended.

Ternes, MP

2001-12-05T23:59:59.000Z

239

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

240

The Systemic Velocity of Eta Carinae  

E-Print Network [OSTI]

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.

Nathan Smith

2004-06-23T23:59:59.000Z

Note: This page contains sample records for the topic "duct high velocity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Supersonic relative velocity effect on the baryonic acoustic oscillation measurements  

SciTech Connect (OSTI)

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.

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

242

Effects of increasing tip velocity on wind turbine rotor design.  

SciTech Connect (OSTI)

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.

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

2014-05-01T23:59:59.000Z

243

PRECISION RADIAL VELOCITIES WITH CSHELL  

SciTech Connect (OSTI)

Radial velocity (RV) identification of extrasolar planets has historically been dominated by optical surveys. Interest in expanding exoplanet searches to M dwarfs and young stars, however, has motivated a push to improve the precision of near-infrared RV techniques. We present our methodology for achieving 58 m s{sup -1} precision in the K band on the M0 dwarf GJ 281 using the CSHELL spectrograph at the 3 m NASA Infrared Telescope Facility. We also demonstrate our ability to recover the known 4 M{sub JUP} exoplanet Gl 86 b and discuss the implications for success in detecting planets around 1-3 Myr old T Tauri stars.

Crockett, Christopher J.; Prato, L. [Lowell Observatory, 1400 W Mars Hill Road, Flagstaff, AZ 86001 (United States); Mahmud, Naved I.; Johns-Krull, Christopher M. [Department of Physics and Astronomy, Rice University, MS-108, 6100 Main Street, Houston, TX 77005 (United States); Jaffe, Daniel T. [Department of Astronomy, University of Texas, R.L. Moore Hall, Austin, TX 78712 (United States); Beichman, Charles A., E-mail: crockett@lowell.edu, E-mail: lprato@lowell.edu, E-mail: naved@rice.edu, E-mail: cmj@rice.edu, E-mail: dtj@astro.as.utexas.edu [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States)

2011-07-10T23:59:59.000Z

244

Newberry EGS Seismic Velocity Model  

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

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.

Templeton, Dennise

245

Newberry EGS Seismic Velocity Model  

SciTech Connect (OSTI)

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.

Templeton, Dennise

2013-10-01T23:59:59.000Z

246

Noise pair velocity and range echo location system  

DOE Patents [OSTI]

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.

Erskine, D.J.

1999-02-16T23:59:59.000Z

247

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?"

248

Constraints on Neutrino Velocities Revisited  

E-Print Network [OSTI]

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.

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

2012-01-27T23:59:59.000Z

249

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

E-Print Network [OSTI]

-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

Otago, University of

250

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

E-Print Network [OSTI]

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

Sethian, James A.

251

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

SciTech Connect (OSTI)

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.

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

2013-02-01T23:59:59.000Z

252

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

DOE Patents [OSTI]

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.

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

2007-01-02T23:59:59.000Z

253

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

E-Print Network [OSTI]

boxes are independent boxes, which are operated in CAV modes. The building continuous commissioning was started on June 2004. It is being commissioned following the approaches used by the Energy Systems Laboratory at Nebraska University, which... 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...

Dong, D.; Liu, M.

2005-01-01T23:59:59.000Z

254

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

SciTech Connect (OSTI)

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%.

Not Available

2014-03-01T23:59:59.000Z

255

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

E-Print Network [OSTI]

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

Yoo, S. J. Ben

256

Impact of Phase Transitions on P Wave Velocities  

SciTech Connect (OSTI)

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.

D Weidner; L Li

2011-12-31T23:59:59.000Z

257

Ducted kinetic Alfven waves in plasma with steep density gradients  

SciTech Connect (OSTI)

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.

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

258

44 Market St - Refurbishment of a Dual Duct Building  

E-Print Network [OSTI]

and West risers with two separate BMS controlled throttling dampers downstream of the fans. While the original intent of the throttling dampers was probably as balancing dampers for the East and West riser, in reality they were resulting in large... of the average floor east group and average floor west group damper positions. This critical static pressure set point reset represents a large energy saving relative to the original fan speed control based on an excessively high static pressure set point...

Bannister, P.; Foo, G.

2013-01-01T23:59:59.000Z

259

Local Energy Velocity of Classical Fields  

E-Print Network [OSTI]

It is proposed to apply a recently developed concept of local wave velocities to the dynamical field characteristics, especially for the canonical field energy density. It is shown that local energy velocities can be derived from the lagrangian directly. The local velocities of zero- and first- order for energy propagation has been obtained for special cases of scalar and vector fields. Some important special cases of these results are discussed.

I. V. Drozdov; A. A. Stahlhofen

2007-04-19T23:59:59.000Z

260

Lowell, Massachusetts, Preserves Historic Home Through Energy...  

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

the historic house will receive upgrades that include a high-velocity, small-duct HVAC system, updated storm windows, and attic insulation. These upgrades will reduce...

Note: This page contains sample records for the topic "duct high velocity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

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)

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.

Cummings, J.; Withers, C.

2014-03-01T23:59:59.000Z

262

Duct injection for SO{sub 2} control, Design Handbook, Volume 1, Process design and engineering guidelines  

SciTech Connect (OSTI)

PETC developed a comprehensive program of coal-related, acid-rain research and development with a major activity area centering on flue gas cleanup and control of SO{sub 2} emissions. Particular emphasis was placed on the retrofit measures for older coal-fired power plants which predate the 1971 New Source Performance Standards. Candidate emission control technologies fall into three categories, depending upon their point of application along the fuel path (i.e., pre, during, or post combustion). The post-combustion, in-duct injection of a calcium-based chemical reagent seemed promising. Preliminary studies showed that reagent injection between the existing air heater and electrostatic precipitator (ESP) could remove between 50-60% of the SO{sub 2} and produce an environmentally safe, dry, solid waste that is easily disposed. Although SO{sub 2} removal efficiencies were less, the estimated capital costs for duct injection technology were low making the economics of duct injection systems seem favorable when compared to conventional wet slurry scrubbers under certain circumstances. With the promulgation of the Clean Air Act Amendments of 1990 came more incentive for the development of low capital cost flue gas desulfurization (FGD) processes. A number of technical problems had to be resolved, however, before duct injection technology could be brought to a state of commercial readiness. The Duct Injection Technology Development Program was launched as a comprehensive, four-year research effort undertaken by PETC to develop this new technology. Completed in 1992, this Duct Injection Design Handbook and the three-dimensional predictive mathematical model constitute two primary end products from this development program. The aim of this design handbook and the accompanying math model is to provide utility personnel with sufficient information to evaluate duct injection technology against competing SO{sub 2} emissions reduction strategies for an existing plant.

NONE

1995-09-01T23:59:59.000Z

263

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]

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.

unknown authors

1994-01-01T23:59:59.000Z

264

Field comparison of the point velocity probe with other groundwater velocity measurement methods  

E-Print Network [OSTI]

Field testing of a new tool for measuring groundwater velocities at the centimeter scale, the point velocity probe (PVP), was undertaken at Canadian Forces Base, Borden, Ontario, Canada. The measurements were performed in ...

Labaky, W.; Devlin, J. F.; Gillham, R. W.

2009-03-14T23:59:59.000Z

265

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

E-Print Network [OSTI]

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 ...

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

2015-01-01T23:59:59.000Z

266

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

SciTech Connect (OSTI)

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.

Not Available

2014-09-01T23:59:59.000Z

267

Investigation of wall friction in noncircular ducts with a rough liner  

E-Print Network [OSTI]

. Civil ~Rn i , I nd , p. 166, P h Ay, 1DDD 2. R k'*1, R M * i, M*ch d I' G 1 ti A~n 1 Viley and. Sons, Inc. , New York, p. 66, 1950, H *I ci er, P. G. , ~atd, P~, d Ai. ~G* d't'* 19: 127(19rr. 7). O; Johnaon, Guy, Jr. , Determination oi' the ~pandit...INVESTIGATION OZ 7('ALL FRICTION IN NONCIHCULAR DUCTS VIITH A ROUGH LINEH A Thesis John Charles Tyler Submitted. to the Graduate School of the Agricultural and Mechanical College of Texas in partial fulfillment of the requirements...

Tyler, John Charles

1959-01-01T23:59:59.000Z

268

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

SciTech Connect (OSTI)

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.

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

269

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

DOE Patents [OSTI]

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.

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

1982-01-01T23:59:59.000Z

270

Modeling velocity dispersion In Gypsy site, Oklahoma  

E-Print Network [OSTI]

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 ...

Alsaadan, Sami Ibrahim

2010-01-01T23:59:59.000Z

271

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

SciTech Connect (OSTI)

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.

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

272

Acoustic measurement of potato cannon velocity  

E-Print Network [OSTI]

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.

Courtney, M; Courtney, Amy; Courtney, Michael

2006-01-01T23:59:59.000Z

273

GALAXY CLUSTER BULK FLOWS AND COLLISION VELOCITIES IN QUMOND  

SciTech Connect (OSTI)

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.

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

274

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

E-Print Network [OSTI]

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...

Liu, G.; Mingsheng, L.

2006-01-01T23:59:59.000Z

275

Exploring Maximum Humidity Control and Energy Conservation Opportunities with Single Duct Single Zone Air-Handling Units  

E-Print Network [OSTI]

Humidity control for single-duct single-zone (SDSZ) constant volume air handling units is known to be a challenge. The operation of these systems is governed by space temperature only. Under mild weather conditions, discharge air temperature can get...

Zhou, J.; Wei, G.; Turner, W. D.; Deng, S.; Claridge, D.

2006-01-01T23:59:59.000Z

276

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

SciTech Connect (OSTI)

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.

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

277

Sandia National Laboratories: high-resolution velocity measurements  

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1development Sandia,evaluatingfull moduleresourcesperform-ance

278

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

E-Print Network [OSTI]

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

Fisk, William

2008-01-01T23:59:59.000Z

279

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

SciTech Connect (OSTI)

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.

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

2014-07-21T23:59:59.000Z

280

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

SciTech Connect (OSTI)

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.

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

Note: This page contains sample records for the topic "duct high velocity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Lagrangian reconstruction of cosmic velocity fields  

E-Print Network [OSTI]

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.

G. Lavaux

2008-01-28T23:59:59.000Z

282

Sound velocity bound and neutron stars  

E-Print Network [OSTI]

It has been conjectured that the velocity of sound in any medium is smaller than the velocity of light in vacuum divided by $\\sqrt{3}$. Simple arguments support this bound in non-relativistic and/or weakly coupled theories. The bound has been demonstrated in several classes of strongly coupled theories with gravity duals and is saturated only in conformal theories. We point out that the existence of neutron stars with masses around two solar masses combined with the knowledge of the equation of state of hadronic matter at "low" densities is in strong tension with this bound.

Paulo F. Bedaque; Andrew W. Steiner

2015-01-25T23:59:59.000Z

283

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

SciTech Connect (OSTI)

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.

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

2008-12-01T23:59:59.000Z

284

Water Velocity Measurements on a Vertical Barrier Screen at the Bonneville Dam Second Powerhouse  

SciTech Connect (OSTI)

Fish screens at hydroelectric dams help to protect rearing and migrating fish by preventing them from passing through the turbines and directing them towards the bypass channels by providing a sweeping flow parallel to the screen. However, fish screens may actually be harmful to fish if they become impinged on the surface of the screen or become disoriented due to poor flow conditions near the screen. Recent modifications to the vertical barrier screens (VBS) at the Bonneville Dam second powerhouse (B2) intended to increase the guidance of juvenile salmonids into the juvenile bypass system (JBS) have resulted in high mortality and descaling rates of hatchery subyearling Chinook salmon during the 2008 juvenile salmonid passage season. To investigate the potential cause of the high mortality and descaling rates, an in situ water velocity measurement study was conducted using acoustic Doppler velocimeters (ADV) in the gatewell slot at Units 12A and 14A of B2. From the measurements collected the average approach velocity, sweep velocity, and the root mean square (RMS) value of the velocity fluctuations were calculated. The approach velocities measured across the face of the VBS varied but were mostly less than 0.3 m/s. The sweep velocities also showed large variances across the face of the VBS with most measurements being less than 1.5 m/s. This study revealed that the approach velocities exceeded criteria recommended by NOAA Fisheries and Washington State Department of Fish and Wildlife intended to improve fish passage conditions.

Hughes, James S.; Deng, Zhiqun; Weiland, Mark A.; Martinez, Jayson J.; Yuan, Yong

2011-11-22T23:59:59.000Z

285

Threshold velocity for environmentally-assisted cracking in low alloy steels  

SciTech Connect (OSTI)

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.

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

1997-04-01T23:59:59.000Z

286

In-depth survey report: Control technology for small business: Evaluation of a flexible duct ventilation system for radiator repair, at A-1 Radiator, Reno, Nevada  

SciTech Connect (OSTI)

An engineering control evaluation was conducted at a radiator repair shop which operated at a very high level of production. The shop had the potential for high exposures to lead (7439921) because of the high volume of work, the number of radiator repair stations, and repairs to huge radiators for mining equipment. Local exhaust ventilation which utilized adjustable arm elephant trunk exhaust hoods had been installed 18 months prior to the visit. The objective of the study was to evaluate the effectiveness of the local exhaust ventilation (LEV) system to control lead exposures during work operations. Time weighted average personal exposures for lead were at or below the OSHA permissible exposure level for ten of 15 mechanics during a high level of production. The elephant trunk ventilation system was capable of controlling lead fumes while shop doors were open, except at one tank in a corner. Work practices were found to be a source of excessive lead exposure. Emissions from a worker's own soldering and from soldering activity upwind of the worker were a major source of lead exposure. Collapse of flexible portions of ducts could reduce exhaust volume. Dampers also showed a tendency to close automatically.

Sheehy, J.W.; Cooper, T.C.; Hall, R.M.; Meier, R.M.

1990-02-01T23:59:59.000Z

287

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

288

3D REGULARIZED VELOCITY FROM 3D DOPPLER RADIAL VELOCITY X. Chen, J.L. Barron, R.E. Mercer  

E-Print Network [OSTI]

3D REGULARIZED VELOCITY FROM 3D DOPPLER RADIAL VELOCITY X. Chen, J.L. Barron, R.E. Mercer Dept, Ontario, M3H 5T4 Paul.Joe@ec.gc.ca ABSTRACT The recent availability of sequences of 3D Doppler radial velocity datasets provides sufficient information to estimate the 3D velocity of Doppler storms. We present

Barron, John

289

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.

290

Seismicity and Improved Velocity Structure in Kuwait  

SciTech Connect (OSTI)

The Kuwait National Seismic Network (KNSN) began operation in 1997 and consists of nine three-component stations (eight short-period and one broadband) and is operated by the Kuwait Institute for Scientific Research. Although the region is largely believed to be aseismic, considerable local seismicity is recorded by KNSN. Seismic events in Kuwait are clustered in two main groups, one in the south and another in the north. The KNSN station distribution is able to capture the southern cluster within the footprint of the network but the northern cluster is poorly covered. Events tend to occur at depths ranging from the free surface to about 20 km. Events in the northern cluster tend to be deeper than those in south, however this might be an artifact of the station coverage. We analyzed KNSN recordings of nearly 200 local events to improve understanding of seismic events and crustal structure in Kuwait, performing several analyses with increasing complexity. First, we obtained an optimized one-dimensional (1D) velocity model for the entire region using the reported KNSN arrival times and routine locations. The resulting model is consistent with a recently obtained model from the joint inversion of receiver functions and surface wave group velocities. Crustal structure is capped by the thick ({approx} 7 km) sedimentary rocks of the Arabian Platform underlain by normal velocities for stable continental crust. Our new model has a crustal thickness of 44 km, constrained by an independent study of receiver functions and surface wave group velocities by Pasyanos et al (2006). Locations and depths of events after relocation with the new model are broadly consistent with those reported by KISR, although a few events move more than a few kilometers. We then used a double-difference tomography technique (tomoDD) to jointly locate the events and estimate three-dimensional (3D) velocity structure. TomoDD is based on hypoDD relocation algorithm and it makes use of both absolute and relative arrival times. We obtained {approx}1500 absolute P and S arrival times and {approx}3200 P and S wave arrival time differences. Event locations do not change greatly when 3D velocity structure is included. Three-dimensional velocity structure, where resolvable, does not differ greatly from our optimized 1D model, indicating that the improved 1D model is adequate for routine event location. Finally, we calculated moment magnitudes, MW, for nearly 155 events using the coda magnitude technique of Mayeda et al., (2003). The fact that most of the relocated events occur below the known sedimentary structures extending to 7 km suggests that they are tectonic in origin. Shallow events within the sedimentary crust in the (southern) Minagish region may be related to oil field activities, although the current study cannot unambiguously determine the source of current seismicity in Kuwait. The improved velocity model reduces the scatter of travel time residuals relative to the locations reported in the KNSN bulletin and may be used for ground motion prediction and hazard estimate studies in Kuwait.

Gok, R M; Rodgers, A J; Al-Enezi, A

2006-01-26T23:59:59.000Z

291

Velocity coordinate spectrum: geometrical aspects of observations  

E-Print Network [OSTI]

We analyze a technique of obtaining turbulence power spectrum using spectral line data along the velocity coordinate, which we refer to as Velocity Coordinate Spectrum (VCS). We formalize geometrical aspects of observation through a single factor, "geometric term". We find that all variety of particular observational configurations can be described using correspondent variants of this term, which we explicitly calculate. This allows us to obtain asymptotics for both parallel lines of sight and crossing lines of sight. The latter case is especially important for studies of turbulence within diffuse ISM in Milky Way. For verification of our results, we use direct calculation of VCS spectra, while the numerical simulations are presented in a companion paper.

A. Chepurnov; A. Lazarian

2007-01-31T23:59:59.000Z

292

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

E-Print Network [OSTI]

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.

Jian-Miin Liu

2003-07-07T23:59:59.000Z

293

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

E-Print Network [OSTI]

(ESL) % Difference (EnergyGauge) Base Case Figure 9. Supply duct area (% of conditioned space). 0 1000 2000 3000 4000 5000 6000 7000 8000 9000 2% 4% 6% 8% 10% A n n u al Co o l i n g U s e ( k W h ) -20% -10% 0% 10% 20% 30% 40% 50% Pe rc e n t a... Figure 15. Supply duct area (% of conditioned space). 0 1000 2000 3000 4000 5000 6000 7000 8000 9000 2% 4% 6% 8% 10% A n n u al Co o l i n g U s e ( k W h ) -20% -10% 0% 10% 20% 30% 40% 50% Pe rc e n t a g e Di ffe re n c e ( % ) fro m B a s e...

Kim, S.; Haberl, J. S.

2007-07-10T23:59:59.000Z

294

Ann. Geophysicae 14, 1480--1486 (1996) EGS --Springer-Verlag 1996 Errors due to random noise in velocity measurement  

E-Print Network [OSTI]

in velocity measurement using incoherent-scatter radar P. J. S. Williams, A. Etemadi, I. W. McCrea, H. Todd- scatter measurements for high signal levels and empha- sised the effect of significant correlation between in measuring a component of ion velocity with an incoherent-scattar radar using a simple long

Paris-Sud XI, Université de

295

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

SciTech Connect (OSTI)

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.

Sippola, Mark R.; Nazaroff, William W.

2002-06-01T23:59:59.000Z

296

Characterization of pipes, drain lines, and ducts using the pipe explorer system  

SciTech Connect (OSTI)

As DOE dismantles its nuclear processing facilities, site managers must employ the best means of disposing or remediating hundreds of miles of potentially contaminated piping and duct work. Their interiors are difficult to access, and in many cases even the exteriors are inaccessible. Without adequate characterization, it must be assumed that the piping is contaminated, and the disposal cost of buried drain lines can be on the order of $1,200/ft and is often unnecessary as residual contamination levels often are below free release criteria. This paper describes the program to develop a solution to the problem of characterizing radioactive contamination in pipes. The technical approach and results of using the Pipe Explorer {trademark} system are presented. The heart of the system is SEA`s pressurized inverting membrane adapted to transport radiation detectors and other tools into pipes. It offers many benefits over other pipe inspection approaches. It has video and beta/gamma detection capabilities, and the need for alpha detection has been addressed through the development of the Alpha Explorer{trademark}. These systems have been used during various stages of decontamination and decommissioning of DOE sites, including the ANL CP-5 reactor D&D. Future improvements and extensions of their capabilities are discussed.

Cremer, C.D.; Kendrick, D.T.; Cramer, E.

1997-05-01T23:59:59.000Z

297

The nuclear fusion reaction rate based on relativistic equilibrium velocity distribution  

E-Print Network [OSTI]

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.

Jian-Miin Liu

2002-10-20T23:59:59.000Z

298

Centerline velocity profile for plain round exhaust hoods  

E-Print Network [OSTI]

, 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...

Martin, Kirksey E

1977-01-01T23:59:59.000Z

299

Propagation Plane waves -High order Modes  

E-Print Network [OSTI]

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

Berlin,Technische Universität

300

Propagation Plane waves -High order Modes  

E-Print Network [OSTI]

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

Berlin,Technische Universität

Note: This page contains sample records for the topic "duct high velocity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

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

E-Print Network [OSTI]

(model DP-25-2500 model, OMEGA ). For pressure differentials more than 5 inch of HtO, an inclined manometer was used. Both systems accuracies were estimated to be + 2% of the measured values. To find the velocity from the measured pressure, measured...

Langari, Abdolreza

1997-01-01T23:59:59.000Z

302

On the Velocity and Intensity Line Asymmetries  

E-Print Network [OSTI]

We show that, if solar 5 min. oscillations are excited by convection in the upper layers of the convective envelope, it is impossible to explain the opposite line asymmetries observed in the velocity and intensity spectra with assumptions on the dissipations which reduce the problem to a second order one. The interpretation of that observation requires to solve the full non-adiabatic problem which is of the fourth or sixth order. We also analyze the causes of line asymmetries in the frame of the general problem and we show that to locate the source, it is better to study line asymmetries not too far from line centers.

M. Gabriel

1997-10-01T23:59:59.000Z

303

Orthogonal-Phase-Velocity Propagation of Electromagnetic Plane Waves  

E-Print Network [OSTI]

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.

Tom G. Mackay; Akhlesh Lakhtakia

2005-11-30T23:59:59.000Z

304

Seismic Velocity Estimation from Time Migration Maria Kourkina Cameron  

E-Print Network [OSTI]

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

Cameron, Maria Kourkina

305

LAMINAR BURNING VELOCITY OF GASOLINES WITH ADDITION OF ETHANOL  

E-Print Network [OSTI]

1 LAMINAR BURNING VELOCITY OF GASOLINES WITH ADDITION OF ETHANOL P. Dirrenberger1 , P.A. Glaude*1 (2014) 162-169" DOI : 10.1016/j.fuel.2013.07.015 #12;2 LAMINAR BURNING VELOCITY OF GASOLINES, Sweden Abstract The adiabatic laminar burning velocities of a commercial gasoline and of a model fuel (n

Boyer, Edmond

306

On Approximating the Translational Velocity of Vortex Rings  

E-Print Network [OSTI]

from this configuration and the system scaling. Here, the accuracy of this approximation is presented orifice in a flat plate contain a converging radial component of velocity. For both configurations. By this definition, the piston velocity is the average jet velocity passing through the orifice independent

Mohseni, Kamran

307

Observations of Velocity Conditions near a Hydroelectric Turbine Draft Tube Exit using ADCP Measurements  

SciTech Connect (OSTI)

Measurement of flow characteristics near hydraulic structures is an ongoing challenge because of the need to obtain rapid measurements of time-varying velocity over a relatively large spatial domain. This paper discusses use of an acoustic Doppler current profiler (ADCP) to measure the rapidly diverging flow exiting from an operating hydroelectric turbine draft tube exit. The resolved three-dimensional velocity vectors show a highly complex and helical flow pattern developed near to and downstream of the exit. Velocity vectors were integrated across the exit and we computed an uneven percentage of flow (67%/33%) passing through the two draft tube barrels at a mid-range turbine discharge, consistent with physical model results. In addition to the three-dimensional velocity vectors, the individual one-dimensional velocities measured by each of the four ADCP beams can be separately used as calibration and validation datasets for numerical and physical models. This technique is demonstrated by comparing along-beam ADCP velocity measurements to data collected in a scaled physical model.

Cook, Christopher B.; Richmond, Marshall C.; Serkowski, John A.

2007-10-01T23:59:59.000Z

308

Force-velocity relations for multiple molecular motor transportation  

E-Print Network [OSTI]

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.

Wang, Ziqing

2009-01-01T23:59:59.000Z

309

Force-velocity relations for multiple-molecular-motor transport  

E-Print Network [OSTI]

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

Ziqing Wang; Ming Li

2009-10-01T23:59:59.000Z

310

Filament velocity scaling laws for warm ions  

SciTech Connect (OSTI)

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.

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

311

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

SciTech Connect (OSTI)

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.

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

312

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

SciTech Connect (OSTI)

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.

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

313

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)

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.

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

314

Initial Examination of Low Velocity Sphere Impact of Glass Ceramics  

SciTech Connect (OSTI)

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.

Morrissey, Timothy G [ORNL; Fox, Ethan E [ORNL; Wereszczak, Andrew A [ORNL; Ferber, Mattison K [ORNL

2012-06-01T23:59:59.000Z

315

Coherence, Strain, and Phase Velocity of Strong Ground Motions in the Mississippi Charles A. Langston  

E-Print Network [OSTI]

ground motions in the deep, unconsolidated Mississippi embayment sediments since there are no comparable within the thick, unconsolidated sedimentary column, the high velocity basement rocks, and small is the existence of thick, unconsolidated sediments that blanket the area and attain thicknesses of up to kilometer

Langston, Charles A.

316

Natural discharge after pulse and cooperative electrodes to enhance droplet velocity in digital microfluidics  

SciTech Connect (OSTI)

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.

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

317

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

E-Print Network [OSTI]

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,

Sippola, Mark R.; Nazaroff, William W.

2002-01-01T23:59:59.000Z

318

Time-resolved particle velocity measurements at impact velocities of 10 km/s  

SciTech Connect (OSTI)

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.

Furnish, M.D.; Chhabildas, L.C.; Reinhart, W.D.

1998-08-01T23:59:59.000Z

319

Out-of-plane ultrasonic velocity measurement  

DOE Patents [OSTI]

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.

Hall, M.S.; Brodeur, P.H.; Jackson, T.G.

1998-07-14T23:59:59.000Z

320

Out-of-plane ultrasonic velocity measurement  

DOE Patents [OSTI]

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.

Hall, Maclin S. (Marietta, GA); Brodeur, Pierre H. (Smyrna, GA); Jackson, Theodore G. (Atlanta, GA)

1998-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "duct high velocity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

True Masses of Radial-Velocity Exoplanets  

E-Print Network [OSTI]

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...

Brown, Robert A

2015-01-01T23:59:59.000Z

322

High-Current Accelerators  

E-Print Network [OSTI]

F i g . 13 F i g . 14 A 48 ACCELERATOR F i g . 25 F i g . 16supply. Extrapolation of accelerator energy and current9 . A-48 high-current accelerator, low-velocity end. Fig.

Lawrence, Ernest O.

1955-01-01T23:59:59.000Z

323

Velocity measurements in the near field of a diesel fuel injector by ultrafast imagery  

E-Print Network [OSTI]

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...

Sedarsky, David; Blaisot, Jean-Bernard; Rozé, Claude

2013-01-01T23:59:59.000Z

324

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...

325

P wave velocity variations in the Coso region, California, derived...  

Open Energy Info (EERE)

Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: P wave velocity variations in the Coso region, California, derived from local earthquake...

326

A novel photonic Doppler velocimetry for transverse velocity measurement  

SciTech Connect (OSTI)

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.

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

327

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...

328

Modified definition of group velocity and electromagnetic energy conservation equation  

E-Print Network [OSTI]

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.

Changbiao Wang

2015-01-19T23:59:59.000Z

329

USING MICRO-SEISMICITY AND SEISMIC VELOCITIES TO MAP SUBSURFACE...  

Open Energy Info (EERE)

USING MICRO-SEISMICITY AND SEISMIC VELOCITIES TO MAP SUBSURFACE GEOLOGIC AND HYDROLOGIC STRUCTURE WITHIN THE COSO GEOTHERMAL FIELD, CALIFORNIA Jump to: navigation, search OpenEI...

330

Using Micro-Seismicity and Seismic Velocities to Map Subsurface...  

Open Energy Info (EERE)

OpenEI Reference LibraryAdd to library Conference Paper: Using Micro-Seismicity and Seismic Velocities to Map Subsurface Geologic and Hydrologic Structure Within the Coso...

331

Effective velocities in fractured media: a numerical study using the ...  

E-Print Network [OSTI]

and precise numerical study of effective velocities in fractured structures. ... In this paper, we ..... A final result is that our numerical simulations of P-, SV- and.

2002-03-18T23:59:59.000Z

332

The thin section rock physics: Modeling and measurement of seismic wave velocity on the slice of carbonates  

SciTech Connect (OSTI)

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.

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

333

Nonlinear peculiar-velocity analysis and PCA  

SciTech Connect (OSTI)

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.

Dekel, A. [and others

2001-02-20T23:59:59.000Z

334

Hydrocarbon saturation determination using acoustic velocities obtained through casing  

DOE Patents [OSTI]

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.

Moos, Daniel (Houston, TX)

2010-03-09T23:59:59.000Z

335

Comparing Glider Observed Velocities and Geostrophic Currents Regina Yopak  

E-Print Network [OSTI]

offshore and brings cold, deep water to fill it's place. The upwelling regime creates a unique coastal. This project endeavors to compare calculated geostrophic velocities to the water velocities measured which the net vertical volume of water is transferred 90° to the right which forces warm, surface waters

Kurapov, Alexander

336

A laser Doppler method for noninvasive measurement of flow velocity  

SciTech Connect (OSTI)

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.

Biggs, G.L.

1986-11-25T23:59:59.000Z

337

Tsallis Entropy Based Velocity Distribution in Open Channel Flows  

E-Print Network [OSTI]

............................................................. 94 32 Dimensionless velocity distribution and parameter M ............................... 96 33 um/ umax versus various M ........................................................................... 99 34 Upper Tiber River basin with location... velocity distribution with different m ... 68 9 Computation of M, ?1 and ?V based on um and umax measured on the Po river (Italy) for different verticals at Pontelagoscuro gauged section during flood event that occurred on February 2, 1985...

Luo, Hao

2010-07-14T23:59:59.000Z

338

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

339

3D NUMERICAL STUDY OF MHD FLOW IN A RECTANGULAR DUCT WITH A FLOW CHANNEL INSERT Damien Sutevski, Sergey Smolentsev, Neil Morley, Mohamed Abdou  

E-Print Network [OSTI]

3D NUMERICAL STUDY OF MHD FLOW IN A RECTANGULAR DUCT WITH A FLOW CHANNEL INSERT Damien Sutevski flow channel insert (FCI). We report our first 3D modeling results for an approximately ideally non with the experimental results in the MHD pressure drop, indicating 3D effects may be significant. The new 3D results

Abdou, Mohamed

340

Discrimination of porosity and fluid saturation using seismic velocity analysis  

DOE Patents [OSTI]

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.

Berryman, James G. (Danville, CA)

2001-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "duct high velocity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

A comparison of light and velocity variations in Semiregular variables  

E-Print Network [OSTI]

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.

T. Lebzelter; L. L. Kiss; K. H. Hinkle

2000-09-21T23:59:59.000Z

342

Measuring Oscillatory Velocity Fields Due to Swimming Algae  

E-Print Network [OSTI]

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.

Guasto, Jeffrey S; Gollub, J P

2010-01-01T23:59:59.000Z

343

On the Representation of Intermediate States in the Velocity Basis  

E-Print Network [OSTI]

Unstable state furnishes a semigroup irreducible representation of the Poincar\\'e group. The state vector is represented by a superposition of energy eigenkets. As a consequence of this superposition, the state vector can be transformed into the rest frame through {\\it a} Lorentz transformation only when the eigenkets are labeled by velocity variable, but not momentum variable. We also clarify the meaning of the velocity variable in the state vector with respect to the velocity derived from kinematical consideration of the scattering process.

B. A. Tay; S. Wickramasekara

2008-01-08T23:59:59.000Z

344

Two-stream instability with time-dependent drift velocity  

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

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.

Qin, Hong [PPPL; Davidson, Ronald C. [PPPL

2014-01-01T23:59:59.000Z

345

Stellar Velocity Dispersion of the Leo A Dwarf Galaxy  

E-Print Network [OSTI]

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.

Warren R. Brown; Margaret J. Geller; Scott J. Kenyon; Michael J. Kurtz

2007-05-08T23:59:59.000Z

346

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...

347

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...

348

Superluminal Velocity of Photons in a Gravitational Background  

E-Print Network [OSTI]

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.

I. B. Khriplovich

1994-11-20T23:59:59.000Z

349

GPS velocity field for the Tien Shan and surrounding regions  

E-Print Network [OSTI]

Measurements at ?400 campaign-style GPS points and another 14 continuously recording stations in central Asia define variations in their velocities both along and across the Kyrgyz and neighboring parts of Tien Shan. They ...

Zubovich, Alexander V.

350

LOW VELOCITY SHPERE IMPACT OF SODA LIME SILICATE GLASS  

SciTech Connect (OSTI)

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.

Morrissey, Timothy G [ORNL; Fox, Ethan E [ORNL; Wereszczak, Andrew A [ORNL; Vuono, Daniel J [ORNL

2012-01-01T23:59:59.000Z

351

Estimating propagation velocity through a surface acoustic wave sensor  

SciTech Connect (OSTI)

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.

Xu, Wenyuan (Oakdale, MN); Huizinga, John S. (Dellwood, MN)

2010-03-16T23:59:59.000Z

352

Vertical velocity in oceanic convection off tropical Australia  

E-Print Network [OSTI]

. . . . . . . v Vl Vl I I 1 3 6 10 Description of the Data Data Processing . . Event Criteria 10 15 21 III RESULTS . . . 26 Cores. Environment 26 34 IV COMPARISON WITH OTHER STUDIES . . . . . 40 Cores... Variations with altitude of median and strongest 10'/o-level statistics of (a) average vertical velocity, (b) maximum vertical velocity, (c) mass flux per unit length normal to the flight track and (d) diameter 32 Figure Page Reconstructed temperature...

Lucas, Christopher

2012-06-07T23:59:59.000Z

353

Velocity of sound in solid methane near melting temperatures  

E-Print Network [OSTI]

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...

Whitehead, John Martin

1968-01-01T23:59:59.000Z

354

Temperature and velocity effects in naphthenic acid corrosion  

SciTech Connect (OSTI)

The effects of temperature and velocity were studied with respect to alloy selection for corrosion resistant service. The amount of molybdenum in the austenitic stainless steel alloys is critical in conferring corrosion resistance on the alloy as the temperature of the environment increases. Velocity effects have been studied in a closed loop hot oil circuit where the stream impinges on the target specimen. Film breakdown is prevented by increasing the molybdenum content.

Craig, H.L. Jr. [Corrosion Prevention and Control, Richmond, VA (United States)

1996-08-01T23:59:59.000Z

355

Interrelationships between air velocity and globe thermometer response  

E-Print Network [OSTI]

INTERRELATIONSHIPS BE~ AIR VELOCITY ANIl GLOBE THERMOMETER RESPONSE A Thesis JANES ROBERT THORNTON Submitted to the Graduate College of Texas ARAN University in partial fulfillment of the requirement for the degree of NASTER OF SCIENCE... August 197$ Najor Subject: Industrial Hygiene INTERRELATIONSHIPS BETWEEZ AIR VELOCITY AND GLOBE THERMOMETER RESPONSE A Thesis JAMES ROBERT THORNTON Approved as to style and content by: h z. an o ommmt ee ad o partmen Me er August 1$7$ ABSTRACT...

Thornton, James Robert

1973-01-01T23:59:59.000Z

356

Uppermost mantle P wave velocities beneath Turkey and Iran  

SciTech Connect (OSTI)

The uppermost mantle P wave velocities beneath Turkey and Iran were estimated by applying the conventional travel time-distance relation method to arrival times of well located earthquakes recorded at a few stations. The average uppermost mantle P wave velocity under Turkey is estimated from two stations of the World Wide Standardized Seismograph Network (WWSSN), Istanbul and Tabriz. The data are consistent with a crust of uniform, but poorly determined, thickness and an uppermost mantle P wave velocity of 7.73 +- 0.08 km/s. This velocity is very similar to that for the Aegean Sea and suggests that its structure could be closely related to that beneath Turkey. For Iran, the results calculated from travel times to three WWSSN stations, Meshed, Shiraz, and Tabriz, can be explained by a crust dipping toward the south-southeast at about 1/sup 0/ with an uppermost mantle P wave velocity of 8.0 +- 0.1 km/s. If the crustal thickness were 34 km in the north it would reach about 49 km in the south. Based on these uppermost mantle velocities, the temperature at Moho beneath Turkey is probably close to the melting temperature of peridotite but that beneath Iran is probably lower.

Chen, C.; Chen, W.; Molnar, P.

1980-01-01T23:59:59.000Z

357

DOE Zero Energy Ready Home Case Study, StreetScape Development...  

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

foam, R-49 open-cell spray-foam sealed attic, an HRV, and a tankless water heater for hydro coil furnace with high-velocity, small-diameter ducts. DOEZERHStreetScapeDevelopme...

358

An evaluation of methodology for seismic qualification of equipment, cable trays, and ducts in ALWR plants by use of experience data  

SciTech Connect (OSTI)

Advanced Reactor Corporation (ARC) has developed a methodology for seismic qualification of equipment, cable trays and ducts in Advanced Light Water Reactor plants. A Panel (members of which acted as individuals) supported by the Office of Nuclear Regulatory Research of the Nuclear Regulatory Commission has evaluated this methodology. The review approach and observations are included in this report. In general, the Panel supports the ARC methodology with some exceptions and provides recommendations for further improvements. 26 refs., 10 figs., 1 tab.

Bandyopadhyay, K.K.; Kana, D.D.; Kennedy, R.P.; Schiff, A.J.

1997-07-01T23:59:59.000Z

359

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

E-Print Network [OSTI]

acceptable indoor air quality (IAQ), the overall outside air (OA) intake ratio has to consider the demands from all the zones with the method provided by ASHRAE 62. Some high-ventilation required rooms make it difficult to use a low OA intake ratio...

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

2007-01-01T23:59:59.000Z

360

Design and Experimental Validation of a Ducted Counter-rotating Axial-flow Fans System  

E-Print Network [OSTI]

,8 ) than the front rotor (FR) diameter to re- duce interaction between the FR tip vortex and the RR blade that the efficiency is strongly increased compared to a conventional rotor or to a rotor-stator stage. The effects a very flexible use, with a large patch of high efficient operating points in the parameter space

Boyer, Edmond

Note: This page contains sample records for the topic "duct high velocity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Exceptional Ground Accelerations and Velocities Caused by Earthquakes  

SciTech Connect (OSTI)

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.

Anderson, John

2008-01-17T23:59:59.000Z

362

VELOCITY ANISOTROPY AND SHAPE BIAS IN THE CAUSTIC TECHNIQUE  

SciTech Connect (OSTI)

We use the Millennium Simulation to quantify the statistical accuracy and precision of the escape-velocity technique for measuring cluster-sized halo masses at z {approx} 0.1. We show that in three dimensions one can measure nearly unbiased (<4%) halo masses (>1.5 Multiplication-Sign 10{sup 14} M{sub Sun} h {sup -1}) with 10%-15% scatter. Line-of-sight projection effects increase the scatter to {approx}25%, where we include the known velocity anisotropies. The classical ''caustic'' technique incorporates a calibration factor that is determined from N-body simulations. We derive and test a new implementation that eliminates the need for calibration and utilizes only the observables: the galaxy velocities with respect to the cluster mean v, the projected positions r{sub p} , an estimate of the Navarro-Frenk-White (NFW) density concentration, and an estimate of the velocity anisotropies {beta}. We find that differences between the potential and density NFW concentrations induce a 10% bias in the caustic masses. We also find that large (100%) systematic errors in the observed ensemble average velocity anisotropies and concentrations translate to small (5%-10%) biases in the inferred masses.

Gifford, Daniel; Miller, Christopher J. [Department of Astronomy, University of Michigan, 500 Church St., Ann Arbor, MI 48109 (United States)

2013-05-10T23:59:59.000Z

363

Surgical, pathological and clinical correlation of Tc-99m DISIDA hepatobiliary imaging in 138 adult males, in the diagnosis of functional cystic duct obstruction VS acute or chronic cholecystitis  

SciTech Connect (OSTI)

Despite the wide acceptance of the hepatobiliary scintigraphy as a popular diagnostic imaging modality for gallbladder and hepatobiliary disease, correlation between radionuclide diagnoses and the final clinical and/or pathologic findings have not been thoroughly evaluated. The lack of correlative studies frequently generates difficulties in making appropriate diagnostic interpretation of the objective findings. A retrospective clinical pathological and surgical correlative study was undertaken by the authors in 138 male veteran patients, who underwent computer assisted minute by minute Tc-99m DISIDA cholescintigraphy. A very high percentage (75%) revealed abnormalities; non-visualization of gallbladder (GB) with normal choledochus system (46%), choledochal obstruction with no GB visualization (13%), choledochal obstruction with normal GB visualization (6%), severe hepatocellular disease with non-diagnostic GB (4%), and delayed GB visualization (longer than 60 minutes) (3%). Non-visualization of GB but normal choledochus demonstrated diverse pathologic etiologies, acute and chronic cholecystitis (64%), S/P cholecystectomy (8%), functional obstruction secondary to sepsis or pancreatitis (6%), and various other pathologies including porcelain GB and cholangitis (22%). The most important cause of choledochal obstruction was mass lesions or local infiltration with metastases (33%) rather than acute cholecystitis (27%). Although the sensitivity (98%) and specificity (92%) for cystic duct obstruction were very high, the specificity decreases significantly for cholecystitis.

Yoo, J.H.K.; Beal, W.H.; Ware, R.W.; Straw, J.D.; Chaudhuri, T.K.

1985-05-01T23:59:59.000Z

364

Analytic solutions for seismic travel time and ray path geometry through simple velocity models.  

SciTech Connect (OSTI)

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.

Ballard, Sanford

2007-12-01T23:59:59.000Z

365

SUBSTRUCTURE IN BULK VELOCITIES OF MILKY WAY DISK STARS  

SciTech Connect (OSTI)

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.

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

366

Planar velocity analysis of diesel spray shadow images  

E-Print Network [OSTI]

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...

Sedarsky, David; Blaisot, J-B; Rozé, C

2012-01-01T23:59:59.000Z

367

E-Print Network 3.0 - average settling velocity Sample Search...  

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

is on the enhancement of the mean particle settling velocity... in a turbulent carrier fluid, as compared to the settling velocity ... Source: Meiburg, Eckart H. - Department of...

368

St. Stephen powerhouse tailrace velocity measurement. Final report  

SciTech Connect (OSTI)

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.

Fagerburg, T.L.

1986-09-01T23:59:59.000Z

369

Edge Turbulence Velocity Changes with Lithium Coating on NSTX  

SciTech Connect (OSTI)

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. __________________________________________________

Cao, A.; Zweben, S. J.; Stotler, D. P.; Bell, M.; Diallo, A.; Kaye, S. M.; LeBlanc, B.

2012-08-10T23:59:59.000Z

370

ELECTROSTATIC MODE ASSOCIATED WITH PINCH VELOCITY IN RFPS  

SciTech Connect (OSTI)

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.

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

371

SGP and TWP (Manus) Ice Cloud Vertical Velocities  

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

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.

Kalesse, Heike

372

Clutter in the GMTI range-velocity map.  

SciTech Connect (OSTI)

Ground Moving Target Indicator (GMTI) radar maps echo data to range and range-rate, which is a function of a moving target's velocity and its position within the antenna beam footprint. Even stationary clutter will exhibit an apparent motion spectrum and can interfere with moving vehicle detections. Consequently it is very important for a radar to understand how stationary clutter maps into radar measurements of range and velocity. This mapping depends on a wide variety of factors, including details of the radar motion, orientation, and the 3-D topography of the clutter.

Doerry, Armin Walter

2009-04-01T23:59:59.000Z

373

SGP and TWP (Manus) Ice Cloud Vertical Velocities  

SciTech Connect (OSTI)

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.

Kalesse, Heike

2013-06-27T23:59:59.000Z

374

Source shape determination with directional fragment-fragment velocity correlations  

E-Print Network [OSTI]

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.

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

375

Dynamic optical properties in graphene: Length versus velocity gauge  

SciTech Connect (OSTI)

The dynamic optical properties of graphene are theoretically investigated in both length gauge and velocity gauge in the presence of ultrafast optical radiation field. The two gauges present different results of dynamic photo-induced carriers and optical conductance due to distinct dependencies on electric field and non-resonant optical absorption, while the two gauges give identical results in the steady state time. It shows that the choice of gauge affects evidently the dynamic optical properties of graphene. The velocity gauge represents an outcome of a real physical experiment.

Dong, H. M.; Han, K., E-mail: han6409@263.net [Department of Physics, China University of Mining and Technology, Xuzhou 221116 (China); Xu, W. [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China); Department of Physics, Yunnan University, Kunming 650091 (China)

2014-02-14T23:59:59.000Z

376

Backpulse and filter feed velocity effects on Norton filter performance  

SciTech Connect (OSTI)

A series of tests have been conducted using the 2.2 ft{sup 2} Norton filter to solve the fouling problems observed with the ETF Norton system. The objective of these tests was to determine filter efficiency as a function of backpulse strength and feed velocity. Based on experimental results, it is recommend that the filters should be operated at the following conditions: (1) Backpulse Transmembrane Pressure/FeedTransmembrane Pressure (BP/FP) > 1.5, preferably 2 or 3. (2) Feed crossflow velocity = 6--8 f/s. It is expected that operation at these conditions should improve performance by 30--60%.

Siler, J.L.

1990-05-08T23:59:59.000Z

377

Fermi velocity renormalization and dynamical gap generation in graphene  

E-Print Network [OSTI]

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.

C. Popovici; C. S. Fischer; L. von Smekal

2015-01-12T23:59:59.000Z

378

The Light Velocity Casimir Effect Does the Velocity of Light Increase when Propagating Between the Casimir Plates?  

E-Print Network [OSTI]

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...

Ostoma, T; Ostoma, Tom; Trushyk, Mike

1999-01-01T23:59:59.000Z

379

Tracer airflow measurement system (TRAMS)  

DOE Patents [OSTI]

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.

Wang, Duo (Albany, CA)

2007-04-24T23:59:59.000Z

380

Velocity Interferometer blanking due to preheating in a double pulse planar experiment  

SciTech Connect (OSTI)

Optical diagnostics, such as VISAR (Velocity Interferometer System for Any Reflector) or SOP (Streaked Optical Pyrometry), have become essential in shock timing experiments. Their high precision allows for accurate measurements of shock velocities, chronometry, and brightness temperature. However, in some instances, these measurements can be compromised. In planar shock coalescence experiments recently performed at the LULI facility [Baton et al., Phys. Rev. Lett. 108, 195002 (2012)], VISAR signal loss was observed. In these experiments, a strong shock launched by a high-intensity spike catches up with a previously shock launched by an earlier, low-intensity beam. The disappearance of the VISAR signal is attributed to a preheating of the coronal plasma by x-rays generated by the high intensity spike. The signal does not disappear if the high-intensity spike starts after VISAR probe beam begins to reflect off of the first shock. The VISAR diagnostic, modeled using an assessment of the optical index in quartz, compares favorably to experimental results. This provides evidence that x-ray preheating can cause blanking of the VISAR signal in quartz.

Laffite, S.; Combis, P.; Clerouin, J.; Recoules, V.; Rousseaux, C.; Videau, L. [CEA, DAM, DIF, F-91297 Arpajon (France); Baton, S. D.; Koenig, M. [LULI, Ecole Polytechnique, CNRS, CEA, UPMC, route de Saclay, 91128 Palaiseau (France)

2014-08-15T23:59:59.000Z

Note: This page contains sample records for the topic "duct high velocity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Effect of the q-nonextensive electron velocity distribution on a magnetized plasma sheath  

SciTech Connect (OSTI)

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.

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

382

Study of Air Ingress Across the Duct During the Accident Conditions  

SciTech Connect (OSTI)

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

Hassan, Yassin

2013-05-06T23:59:59.000Z

383

Measurement of turbulent wind velocities using a rotating boom apparatus  

SciTech Connect (OSTI)

The present report covers both the development of a rotating-boom facility and the evaluation of the spectral energy of the turbulence measured relative to the rotating boom. The rotating boom is composed of a helicopter blade driven through a pulley speed reducer by a variable speed motor. The boom is mounted on a semiportable tower that can be raised to provide various ratios of hub height to rotor diameter. The boom can be mounted to rotate in either the vertical or horizontal plane. Probes that measure the three components of turbulence can be mounted at any location along the radius of the boom. Special hot-film sensors measured two components of the turbulence at a point directly in front of the rotating blade. By using the probe rotated 90/sup 0/ about its axis, the third turbulent velocity component was measured. Evaluation of the spectral energy distributions for the three components of velocity indicates a large concentration of energy at the rotational frequency. At frequencies slightly below the rotational frequency, the spectral energy is greatly reduced over that measured for the nonrotating case measurements. Peaks in the energy at frequencies that are multiples of the rotation frequency were also observed. We conclude that the rotating boom apparatus is suitable and ready to be used in experiments for developing and testing sensors for rotational measurement of wind velocity from wind turbine rotors. It also can be used to accurately measure turbulent wind for testing theories of rotationally sampled wind velocity.

Sandborn, V.A.; Connell, J.R.

1984-04-01T23:59:59.000Z

384

THE VELOCITY DEPENDENCE OF AERODYNAMIC DRAG: A PRIMER FOR MATHEMATICIANS  

E-Print Network [OSTI]

THE VELOCITY DEPENDENCE OF AERODYNAMIC DRAG: A PRIMER FOR MATHEMATICIANS LYLE N. LONG and HOWARD­entry of the space shuttle into the earth's atmosphere. Dimensional analysis is an important tool in aerodynamics­T E X 1 #12; For detailed information on the aerodynamics and fluid mechanics pertinent to this paper

385

Brady 1D seismic velocity model ambient noise prelim  

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

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.

Mellors, Robert J.

386

Velocity Autocorrelation Functions and Diffusion of Dusty Plasma  

SciTech Connect (OSTI)

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.

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

387

Brady 1D seismic velocity model ambient noise prelim  

SciTech Connect (OSTI)

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.

Mellors, Robert J.

2013-10-25T23:59:59.000Z

388

Measurements of Laminar Flame Velocity for Components of Natural Gas  

E-Print Network [OSTI]

, BP 20451, 1 Rue Grandville, 54001 Nancy, France 2 Division of Combustion Physics, Lund University flame velocity of components of natural gas, methane, ethane, propane, and nbutane as well as of binary performed by the heat flux method using a newly built flat flame adiabatic burner at atmospheric pressure

Paris-Sud XI, Université de

389

Harmonic analysis of the Ha velocity field of NGC 4254  

E-Print Network [OSTI]

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.

Laurent Chemin; Olivier Hernandez; Chantal Balkowski; Claude Carignan; Philippe Amram

2005-12-20T23:59:59.000Z

390

Feedback on vertical velocity. Rotation, convection, self-sustaining process.  

E-Print Network [OSTI]

Feedback on vertical velocity. Rotation, convection, self-sustaining process. Fabian Waleffe the mechanisms involved in the nonlinear feedback from u to v, yielding a self-sustaining process for shear flows feedback from the streak instability into the rolls sufficient to lead to a self-sustaining process

Lebovitz, Norman

391

Continued Evaluation of the Pulse-Echo Ultrasonic Instrument for Critical Velocity Determination during Hanford Tank Waste Transfer Operations - 12518  

SciTech Connect (OSTI)

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)

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

392

Low Velocity Sphere Impact of a Soda Lime Silicate Glass  

SciTech Connect (OSTI)

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.

Wereszczak, Andrew A [ORNL; Fox, Ethan E [ORNL; Morrissey, Timothy G [ORNL; Vuono, Daniel J [ORNL

2011-10-01T23:59:59.000Z

393

Microstructure and Property Evolution in Advanced Cladding and Duct Materials Under Long-Term and Elevated Temperature Irradiation: Modeling and Experimental Investigation  

SciTech Connect (OSTI)

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.

Wirth, Brian; Morgan, Dane; Kaoumi, Djamel; Motta, Arthur

2013-12-01T23:59:59.000Z

394

Near-Surface Shear-Wave Velocity Measurements in Unlithified Sediment  

E-Print Network [OSTI]

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...

Rickards, Benjamin Thomas

2011-05-31T23:59:59.000Z

395

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)

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.

NONE

1996-11-01T23:59:59.000Z

396

Velocity and void distribution in a counter-current two-phase flow  

SciTech Connect (OSTI)

Different flow regimes were investigated in a horizontal channel. Simulating a hot leg injection in case of a loss of coolant accident or flow conditions in reflux condenser mode, the hydraulic jump and partially reversed flow were identified as major constraints for a high amount of entrained water. Trying to simulate the reflux condenser mode, the test section now includes an inclined section connected to a horizontal channel. The channel is 90 mm high and 110 mm wide. Tests were carried out for water and air at ambient pressure and temperature. High speed video-metry was applied to obtain velocities from flow pattern maps of the rising and falling fluid. In the horizontal part of the channel with partially reversed flow the fluid velocities were measured by planar particle image velocimetry. To obtain reliable results for the gaseous phase, this analysis was extended by endoscope measurements. Additionally, a new method based on the optical refraction at the interface between air and water in a back-light was used to obtain time-averaged void fraction. (authors)

Gabriel, S.; Schulenberg, T. [Karlsruhe Inst. of Technologies KIT, Inst. for Nuclear and Energy Technologies IKET, Hermann-von-Helmholz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Laurien, E. [Univ. of Stuttgart, Inst. for Nuclear Technology and Energy Systems IKE, Pfaffenwaldring 31, 70569 Stuttgart (Germany)

2012-07-01T23:59:59.000Z

397

The application of boundary layer removal to a 90 degree bend used as a flow turing device  

E-Print Network [OSTI]

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...

Smith, Edward Harrison

1959-01-01T23:59:59.000Z

398

THE RADIAL VELOCITY EXPERIMENT (RAVE): FOURTH DATA RELEASE  

SciTech Connect (OSTI)

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.

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

399

Measuring In-Situ Mdf Velocity Of Detonation  

DOE Patents [OSTI]

A system for determining the velocity of detonation of a mild detonation fuse mounted on the surface of a device includes placing the device in a predetermined position with respect to an apparatus that carries a couple of sensors that sense the passage of a detonation wave at first and second spaced locations along the fuse. The sensors operate a timer and the time and distance between the locations is used to determine the velocity of detonation. The sensors are preferably electrical contacts that are held spaced from but close to the fuse such that expansion of the fuse caused by detonation causes the fuse to touch the contact, causing an electrical signal to actuate the timer.

Horine, Frank M. (Albuquerque, NM); James, Jr., Forrest B. (Albuquerque, NM)

2005-10-25T23:59:59.000Z

400

Velocity renormalization in graphene from lattice Monte Carlo  

E-Print Network [OSTI]

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.

Joaquín E. Drut; Timo A. Lähde

2014-03-26T23:59:59.000Z

Note: This page contains sample records for the topic "duct high velocity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

The critical velocity in the BEC-BCS crossover  

E-Print Network [OSTI]

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.

Wolf Weimer; Kai Morgener; Vijay Pal Singh; Jonas Siegl; Klaus Hueck; Niclas Luick; Ludwig Mathey; Henning Moritz

2014-08-22T23:59:59.000Z

402

Velocity and charge reconstruction with the AMS/RICH detector  

E-Print Network [OSTI]

The Alpha Magnetic Spectrometer (AMS), to be installed on the International Space Station (ISS) in 2008, will be equipped with a proximity focusing Ring Imaging CHerenkov detector (RICH). This detector will be equipped with a dual radiator (aerogel+NaF), a lateral conical mirror and a detection plane made of 680 photomultipliers and light-guides, enabling measurements of particle electric charge and velocity. A likelihood method for the Cherenkov angle reconstruction was applied leading to a velocity determination for protons with a resolution around 0.1%. The electric charge reconstruction is based on the counting of the number of photoelectrons and on an overall efficiency estimation on an event-by-event basis. Results from the application of both methods are presented.

Arruda, Luísa; Borges, João; Carmo, Fernando; Gonçalves, Patrícia; Pimenta, Mário

2008-01-01T23:59:59.000Z

403

The AMS-RICH velocity and charge reconstruction  

E-Print Network [OSTI]

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 performance...

Barão, F; Arruda, L; Baret, B; Barrau, A; Barreira, G; Belmont, E; Berdugo, J; Borges, J; Buénerd, M; Casadei, D; Casaus, J; Cortina, E; Costado, M; Crespo, D; Delgado, C; Díaz, C; Derome, L; Gonçalves, P; Garcia-Lopez, R; de la Guia, C; Herrero, A; Lanciotti, E; Laurenti, G; Malinin, A; Maña, C; Marin, J; Mangin-Brinet, M; Martínez, G; Menchaca-Rocha, A; Palomares, C; Pereira, R; Pimenta, M; Putze, A; Sallaz-Damaz, Y; Seo, E S; Sevilla, I; Torrento, A; Vargas-Trevino, M; Veziant, O

2007-01-01T23:59:59.000Z

404

Low velocity ion stopping in binary ionic mixtures  

SciTech Connect (OSTI)

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.

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

405

The AMS-RICH velocity and charge reconstruction  

E-Print Network [OSTI]

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.

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

406

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]

Company, Red}ands, CA) 17 3. 5 industrial Air Blender 3. 6 Interpretation of the model code for the blender . . . 3. 7 Type IV Air Blender 19 3. 8 Example of location of traverse points in circular or non-circular duct (ANSI/I IPS N13. 1...-lll-l, mode-A. COV for particle concentration profiles . . . . . 82 6. 16 Configuration-111-2, mode-B. COV for particle concentration profiles . . . . . 82 FIGURE Page 6. 17 Configuration-111-3, mode-B. COV for particle concentration profiles downstream...

Han, Tae Won

2003-01-01T23:59:59.000Z

407

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)  

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 on Delicious Rank EERE:Year in Review: TopEnergy DOEDealingVehicle1 Closing the Circle: TheDraftforDuctless,Ducts

408

Buried and Encapsulated Ducts, Jacksonville, Florida (Fact Sheet), Building America Case Study: Technology Solutions for New and Existing Homes, Building Technologies Office (BTO)  

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 on Delicious Rank EERE:Year in Review: Top FiveDepartment of Energy BuildingsBuried and Encapsulated Ducts

409

Boltzmann Solver with Adaptive Mesh in Velocity Space  

SciTech Connect (OSTI)

We describe the implementation of direct Boltzmann solver with Adaptive Mesh in Velocity Space (AMVS) using quad/octree data structure. The benefits of the AMVS technique are demonstrated for the charged particle transport in weakly ionized plasmas where the collision integral is linear. We also describe the implementation of AMVS for the nonlinear Boltzmann collision integral. Test computations demonstrate both advantages and deficiencies of the current method for calculations of narrow-kernel distributions.

Kolobov, Vladimir I.; Arslanbekov, Robert R. [CFD Research Corporation, 215 Wynn Dr, Huntsville, AL, 35803 (United States); Frolova, Anna A. [Dorodnicyn Computing Centre of the Russian Academy of Sciences, Vavilova Str., 40, Moscow, 119333 (Russian Federation)

2011-05-20T23:59:59.000Z

410

Extracting Fish and Water Velocity from Doppler Profiler Data  

E-Print Network [OSTI]

Extracting Fish and Water Velocity from Doppler Profiler Data �º Ð 1 ¸ � � �¹ � Ý�¹� � 2 1 to measure fish swimming speeds. This is possible when fish form schools that are large enough so that the multiple Doppler sonar beams are sampling the fish speeds at the same time. In situations where fish

deYoung, Brad

411

Studies of the velocity fields near a submerged rectangular object  

E-Print Network [OSTI]

of the time periodic waves past a submerged rectangular object. For sotne wave conditions, large energy dissipation occurred at the submerged object due to vortex generation. The amount of energy dissipation was examined by comparing incident wave energy... object. A two component laser-Doppler anemometer (LDA) was used to obtain detailed measurements of the instantaneous velocity field and flow visualization was conducted to study the vortex structure around the submerged object. The measured wave...

Kim, Young-Ki

2012-06-07T23:59:59.000Z

412

Obtaining anisotropic velocity data for proper depth seismic imaging  

SciTech Connect (OSTI)

The paper deals with the problem of obtaining anisotropic velocity data due to continuous acoustic impedance-based measurements while scanning in the axial direction along the walls of the borehole. Diagrams of full conductivity of the piezoceramic transducer were used to derive anisotropy parameters of the rock sample. The measurements are aimed to support accurate depth imaging of seismic data. Understanding these common anisotropy effects is important when interpreting data where it is present.

Egerev, Sergey; Yushin, Victor; Ovchinnikov, Oleg; Dubinsky, Vladimir; Patterson, Doug [Andreyev Acoustics Institute, Moscow, 117036 (Russian Federation); Baker Hughes, Inc, 2001 Rankin Road, Houston, TX, 77073 (United States)

2012-05-24T23:59:59.000Z

413

Time, Distance, Velocity, Redshift: a personal guided tour  

E-Print Network [OSTI]

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

T. Kiang

2003-08-01T23:59:59.000Z

414

Design of regulated velocity flow assurance device for petroleum industry  

E-Print Network [OSTI]

flowmeter, which monitors the bypass flow. A motorized butterfly valve is used for actually controlling the bypass flow. In addition to cleaning, the proposed pig utilizes on-board electronics like accelerom- eter and pressure transducers to store the data... . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 B. Concept 1 : Governor Pig . . . . . . . . . . . . . . . . . . . . 35 vii CHAPTER Page C. Concept 2 : Pig Velocity Control Using Mechanical Braking . 39 D. Concept 3 : Bypass Control Using Motorized Butterfly Valve . 40 E. Conclusion...

Yardi, Chaitanya Narendra

2005-02-17T23:59:59.000Z

415

Experimental investigation of velocity biasing in laser Doppler anemometry  

E-Print Network [OSTI]

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... was the McLaughlin Tiederman 3-D weighting factor, time between data weighting factor, equal time interval sampling and analogue instrumentation measurements. The ana- logue instrumentation measurements were obtained from the analogue frequency outputs...

Wiedner, Brian Gregory

1988-01-01T23:59:59.000Z

416

TURBULENCE-INDUCED RELATIVE VELOCITY OF DUST PARTICLES. I. IDENTICAL PARTICLES  

SciTech Connect (OSTI)

We study the relative velocity of inertial particles suspended in turbulent flows and discuss implications for dust particle collisions in protoplanetary disks. We simulate a weakly compressible turbulent flow, evolving 14 particle species with friction timescale, ?{sub p}, covering the entire range of scales in the flow. The particle Stokes numbers, St, measuring the ratio of ?{sub p} to the Kolmogorov timescale, are in the range 0.1 ?< St ?< 800. Using simulation results, we show that the model by Pan and Padoan gives satisfactory predictions for the rms relative velocity between identical particles. The probability distribution function (PDF) of the relative velocity is found to be highly non-Gaussian. The PDF tails are well described by a 4/3 stretched exponential function for particles with ?{sub p} ? 1-2 T{sub L}, where T{sub L} is the Lagrangian correlation timescale, consistent with a prediction based on PP10. The PDF approaches Gaussian only for very large particles with ?{sub p} ?> 54 T{sub L}. We split particle pairs at given distances into two types with low and high relative speeds, referred to as continuous and caustic types, respectively, and compute their contributions to the collision kernel. Although amplified by the effect of clustering, the continuous contribution vanishes in the limit of infinitesimal particle distance, where the caustic contribution dominates. The caustic kernel per unit cross section rises rapidly as St increases toward ? 1, reaches a maximum at ?{sub p} ? 2 T{sub L}, and decreases as ?{sub p}{sup -1/2} for ?{sub p} >> T{sub L}.

Pan, Liubin [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Padoan, Paolo, E-mail: lpan@cfa.harvard.edu, E-mail: ppadoan@icc.ub.edu [ICREA and ICC, University of Barcelona, Marti i Franquès 1, E-08028 Barcelona (Spain)

2013-10-10T23:59:59.000Z

417

RVSAO 2.0: Digital Redshifts and Radial Velocities  

E-Print Network [OSTI]

RVSAO is a set of programs to obtain redshifts and radial velocities from digital spectra. RVSAO operates in the IRAF(Tody 1986, 1993) environment. The heart of the system is xcsao, which implements the cross-correlation method, and is a direct descendant of the system built by Tonry and Davis (1979). emsao uses intelligent heuristics to search for emission lines in spectra, then fits them to obtain a redshift. sumspec shifts and sums spectra to build templates for cross-correlation. linespec builds synthetic spectra given a list of spectral lines. bcvcorr corrects velocities for the motion of the earth. We discuss in detail the parameters necessary to run xcsao and emsao properly. We discuss the reliability and error associated with xcsao derived redshifts. We develop an internal error estimator, and we show how large, stable surveys can be used to develop more accurate error estimators. We develop a new methodology for building spectral templates for galaxy redshifts. We show how to obtain correlation velocities using emission line templates. Emission line correlations are substantially more efficient than the previous standard technique, automated emission line fitting. We compare the use of RVSAO with new methods, which use Singular Value Decomposition and $\\chi^2$ fitting techniques.

Michael J. Kurtz; Douglas J. Mink

1998-03-25T23:59:59.000Z

418

Measurements of Spatially Resolved Velocity Variations in Shock Compressed Heterogeneous Materials Using a Line-Imaging Velocity Interferometer  

SciTech Connect (OSTI)

Relatively straightforward changes in the optical design of a conventional optically recording velocity interferometer system (ORVIS) can be used to produce a line-imaging velocity interferometer wherein both temporal and spatial resolution can be adjusted over a wide range. As a result line-imaging ORVIS can be tailored to a variety of specific applications involving dynamic deformation of heterogeneous materials as required by the characteristic length scale of these materials (ranging from a few {micro}m for ferroelectric ceramics to a few mm for concrete). A line-imaging ORVIS has been successfully interfaced to the target chamber of a compressed gas gun driver and fielded on numerous tests in combination with simultaneous measurements using a dual delay-leg, ''push-pull'' VISAR system. These tests include shock loading of glass-reinforced polyester composites, foam reverberation experiments (measurements at the free surface of a thin aluminum plate impacted by foam), and measurements of dispersive velocity in a shock-loaded explosive simulant (sugar). Comparison of detailed spatially-resolved material response to the spatially averaged VISAR measurements will be discussed.

ASAY,JAMES R.; CHHABILDAS,LALIT C.; KNUDSON,MARCUS D.; TROTT,WAYNE M.

1999-09-01T23:59:59.000Z

419

Duct and cladding alloy  

DOE Patents [OSTI]

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.

Korenko, Michael K. (Rockville, MD)

1983-01-01T23:59:59.000Z

420

Spectroscopic measurement of ion temperature and ion velocity distributions in the flux-coil generated FRC  

SciTech Connect (OSTI)

One aim of the flux-coil generated field reversed configuration at Tri Alpha Energy (TAE) is to establish the plasma where the ion rotational energy is greater than the ion thermal energy. To verify this, an optical diagnostic was developed to simultaneously measure the Doppler velocity-shift and line-broadening using a 0.75 m, 1800 groves/mm, spectrometer. The output spectrum is magnified and imaged onto a 16-channel photomultiplier tube (PMT) array. The individual PMT outputs are coupled to high-gain, high-frequency, transimpedance amplifiers, providing fast-time response. The Doppler spectroscopy measurements, along with a survey spectrometer and photodiode-light detector, form a suite of diagnostics that provide insights into the time evolution of the plasma-ion distribution and current when accelerated by an azimuthal-electric field.

Gupta, D.; Gota, H.; Hayashi, R.; Kiyashko, V.; Morehouse, M.; Primavera, S. [Tri Alpha Energy, Inc., Rancho Santa Margarita, California 92688 (United States); Bolte, N. [Tri Alpha Energy, Inc., Rancho Santa Margarita, California 92688 (United States); Department of Physics and Astronomy, University of California, Irvine, California 92697 (United States); Marsili, P. [Department of Physics, University of Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Roche, T. [Department of Physics and Astronomy, University of California, Irvine, California 92697 (United States); Wessel, F. [Department of Physics and Astronomy, University of California, Irvine, California 92697 (United States); Tri Alpha Energy, Inc., Rancho Santa Margarita, California 92688 (United States)

2010-10-15T23:59:59.000Z

Note: This page contains sample records for the topic "duct high velocity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Low Velocity Sphere Impact of a Borosilicate Glass  

SciTech Connect (OSTI)

This report summarizes US Army TARDEC sponsored work at Oak Ridge National Laboratory (ORNL) involving low velocity (< 30 m/s or < 65 mph) ball impact testing of Borofloat borosilicate glass, and is a follow-up to a similar study completed by the authors on Starphire soda-lime silicate glass last year. The response of the borosilicate glass to impact testing at different angles was also studied. The Borofloat glass was supplied by the US Army Research Laboratory and its tin-side was impacted or indented. The intent was to better understand low velocity impact response in the Borofloat. Seven sphere materials were used whose densities bracket that of rock: borosilicate glass, soda-lime silicate glass, silicon nitride, aluminum oxide, zirconium oxide, carbon steel, and a chrome steel. A gas gun or a ball-drop test setup was used to produce controlled velocity delivery of the spheres against the glass tile targets. Minimum impact velocities to initiate fracture in the Borofloat were measured and interpreted in context to the kinetic energy of impact and the elastic property mismatch between the seven sphere-Borofloat-target combinations. The primary observations from this low velocity (< 30 m/s or < 65 mph) testing were: (1) BS glass responded similarly to soda-lime silicate glass when spherically indented but quite differently under sphere impact conditions; (2) Frictional effects contributed to fracture initiation in BS glass when it spherically indented. This effect was also observed with soda-lime silicate glass; (3) The force necessary to initiate fracture in BS glass under spherical impact decreases with increasing elastic modulus of the sphere material. This trend is opposite to what was observed with soda-lime silicate glass. Friction cannot explain this trend and the authors do not have a legitimate explanation for it yet; (4) The force necessary to initiate contact-induced fracture is higher under dynamic conditions than under quasi-static conditions. That difference decreases with increasing elastic modulus mismatch between the sphere material and borosilicate This trend was opposite in soda-lime silicate glass; (5) Fracture in borosilicate glass occurs at lower velocities (i.e., easier) at 24{sup o} than at 0{sup o} (orthogonal) and 46{sup o} of impact for the same probability of failure. Though not analyzed yet, this suggests that a convolution of kinetic energy and friction is contributing to that trend; (6) There is a subtle indication there was intra-tile differences in spherical indentation RCIF. This likely is not a material property nor exclusive to borosilicate glass, rather, it is a statistical response of a combination of local, surface-located flaw and imposed tensile stress. Understanding of the surface flaw population and flaw positioning can likely enable prediction of spherical indentation RCIF; and (7) Contact-induced fracture did not initiate in the Borofloat BS for impact kinetic energies up to {approx} 20 mJ. For kinetic energies between {approx} 20-150 mJ, fracture sometimes initiated. Contact-induced fracture would always occur for impact energies > 150 mJ. The energy values, and their boundaries, were much lower for BS glass than they were for soda-lime silicate glass.

Morrissey, Timothy G [ORNL; Ferber, Mattison K [ORNL; Wereszczak, Andrew A [ORNL; Fox, Ethan E [ORNL

2012-05-01T23:59:59.000Z

422

An approach to improving transporting velocity in the long-range ultrasonic transportation of micro-particles  

SciTech Connect (OSTI)

In existing ultrasonic transportation methods, the long-range transportation of micro-particles is always realized in step-by-step way. Due to the substantial decrease of the driving force in each step, the transportation is lower-speed and stair-stepping. To improve the transporting velocity, a non-stepping ultrasonic transportation approach is proposed. By quantitatively analyzing the acoustic potential well, an optimal region is defined as the position, where the largest driving force is provided under the condition that the driving force is simultaneously the major component of an acoustic radiation force. To keep the micro-particle trapped in the optimal region during the whole transportation process, an approach of optimizing the phase-shifting velocity and phase-shifting step is adopted. Due to the stable and large driving force, the displacement of the micro-particle is an approximately linear function of time, instead of a stair-stepping function of time as in the existing step-by-step methods. An experimental setup is also developed to validate this approach. Long-range ultrasonic transportations of zirconium beads with high transporting velocity were realized. The experimental results demonstrated that this approach is an effective way to improve transporting velocity in the long-range ultrasonic transportation of micro-particles.

Meng, Jianxin; Mei, Deqing, E-mail: meidq-127@zju.edu.cn; Yang, Keji; Fan, Zongwei [State Key Lab of Fluid Power Transmission and Control, Department of Mechanical Engineering, Zhejiang University, Hangzhou, Zhejiang 310027 (China)

2014-08-14T23:59:59.000Z

423

Derivation of site-specific relationships between hydraulic parameters and p-wave velocities based on hydraulic and seismic tomography  

SciTech Connect (OSTI)

In this study, hydraulic and seismic tomographic measurements were used to derive a site-specific relationship between the geophysical parameter p-wave velocity and the hydraulic parameters, diffusivity and specific storage. Our field study includes diffusivity tomograms derived from hydraulic travel time tomography, specific storage tomograms, derived from hydraulic attenuation tomography, and p-wave velocity tomograms, derived from seismic tomography. The tomographic inversion was performed in all three cases with the SIRT (Simultaneous Iterative Reconstruction Technique) algorithm, using a ray tracing technique with curved trajectories. The experimental set-up was designed such that the p-wave velocity tomogram overlaps the hydraulic tomograms by half. The experiments were performed at a wellcharacterized sand and gravel aquifer, located in the Leine River valley near Göttingen, Germany. Access to the shallow subsurface was provided by direct-push technology. The high spatial resolution of hydraulic and seismic tomography was exploited to derive representative site-specific relationships between the hydraulic and geophysical parameters, based on the area where geophysical and hydraulic tests were performed. The transformation of the p-wave velocities into hydraulic properties was undertaken using a k-means cluster analysis. Results demonstrate that the combination of hydraulic and geophysical tomographic data is a promising approach to improve hydrogeophysical site characterization.

Brauchler, R.; Doetsch, J.; Dietrich, P.; Sauter, M.

2012-01-10T23:59:59.000Z

424

The radial velocity profile of the filament galaxies in the vicinity of the Virgo cluster as a test of gravity  

E-Print Network [OSTI]

The radial velocities of the galaxies in the vicinity of a massive cluster shows deviation from the pure Hubble flow due to their gravitational interaction with the cluster. According to a recent study of Falco et al. with a high-resolution N-body simulation based on General Relativity (GR), the radial velocity profile of the galaxies located at distances larger than three times the virial radius of a neighbour cluster has a universal shape and could be reconstructed from direct observables provided that the galaxies are distributed along one dimensional filament. Analyzing the narrow filamentary structure identified by Kim et al. in the vicinity of the Virgo cluster from the NASA-Sloan-Atlas catalog, we reconstruct the radial velocity profile of the Virgo filament galaxies and compare it with the universal formula derived by Falco et al. It is found that unless the virial mass of the Virgo cluster exceeds $10^{15}\\,h^{-1}M_{\\odot}$ the universal formula fails to describe the reconstructed radial velocity pro...

Lee, Jounghun; Rey, Soo-Chang

2015-01-01T23:59:59.000Z

425

Corrosion behavior of zirconia-coated Hastelloy X in a high-temperature helium environment  

SciTech Connect (OSTI)

The corrosion behavior of Hastelloy X coated with (NiCrAl)/(ZrO/sub 2/-CaC/sub 2/) was examined, after serving as the liner tube of helium engineering demonstration loop (HENDEL) hot gas duct. The Hastelloy X with the ceramic coating system was exposed to high-temperature helium gas for --6000 h. The compositions of oxide films formed on Hastelloy X were entirely different between the noncoated and ceramic-coated tubes.

Kondo, Y.; Fukaya, K.

1989-01-01T23:59:59.000Z

426

Velocity bunching in travelling wave accelerator with low acceleration gradient  

E-Print Network [OSTI]

We present the analytical and simulated results concerning the influences of the acceleration gradient in the velocity bunching process, which is a bunch compression scheme that uses a traveling wave accelerating structure as a compressor. Our study shows that the bunch compression application with low acceleration gradient is more tolerant to phase jitter and more successful to obtain compressed electron beam with symmetrical longitudinal distribution and low energy spread. We also present a transverse emittance compensation scheme to compensate the emittance growth caused by the increasing of the space charge force in the compressing process that is easy to be adjusted for different compressing factors.

Huang, Rui-Xuan; Li, Wei-Wei; Jia, Qi-Ka

2013-01-01T23:59:59.000Z

427

Cloud-Scale Vertical Velocity and Turbulent Dissipation Rate Retrievals  

SciTech Connect (OSTI)

Time-height fields of retrieved in-cloud vertical wind velocity and turbulent dissipation rate, both retrieved primarily from vertically-pointing, Ka-band cloud radar measurements. Files are available for manually-selected, stratiform, mixed-phase cloud cases observed at the North Slope of Alaska (NSA) site during periods covering the Mixed-Phase Arctic Cloud Experiment (MPACE, late September through early November 2004) and the Indirect and Semi-Direct Aerosol Campaign (ISDAC, April-early May 2008). These time periods will be expanded in a future submission.

Shupe, Matthew

2013-05-22T23:59:59.000Z

428

Cloud-Scale Vertical Velocity and Turbulent Dissipation Rate Retrievals  

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

Time-height fields of retrieved in-cloud vertical wind velocity and turbulent dissipation rate, both retrieved primarily from vertically-pointing, Ka-band cloud radar measurements. Files are available for manually-selected, stratiform, mixed-phase cloud cases observed at the North Slope of Alaska (NSA) site during periods covering the Mixed-Phase Arctic Cloud Experiment (MPACE, late September through early November 2004) and the Indirect and Semi-Direct Aerosol Campaign (ISDAC, April-early May 2008). These time periods will be expanded in a future submission.

Shupe, Matthew

429

Property:Maximum Velocity(m/s) | Open Energy Information  

Open Energy Info (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 on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: Energy ResourcesLoadingPenobscot County,ContAddr2 Jump to:ManagingFieldOffice Jump to: navigation,Velocity(m/s)

430

E-Print Network 3.0 - a-type hyper-velocity star Sample Search...  

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

hyper-velocity star Search Powered by Explorit Topic List Advanced Search Sample search results for: a-type hyper-velocity star Page: << < 1 2 3 4 5 > >> 1 Jahresbericht 2008...

431

E-Print Network 3.0 - additional radial velocity Sample Search...  

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

Search Sample search results for: additional radial velocity Page: << < 1 2 3 4 5 > >> 1 3D Least Squares Velocity from 3D Doppler Radial X. Chen, J.L. Barron, R.E. Mercer Summary:...

432

Evidence for a critical velocity in a Bose-Einstein condensed gas  

E-Print Network [OSTI]

We have studied dissipation in a Bose--Einstein condensed gas by moving a blue detuned laser beam through the condensate at different velocities. Strong heating was observed only above a critical velocity.

C. Raman; M. Kohl; R. Onofrio; D. S. Durfee; C. E. Kuklewicz; Z. Hadzibabic; W. Ketterle

1999-09-07T23:59:59.000Z

433

Cosmic density and velocity fields in Lagrangian perturbation theory  

E-Print Network [OSTI]

A first- and second-order relation between cosmic density and peculiar-velocity fields is presented. The calculation is purely Lagrangian and it is derived using the second-order solutions of the Lagrange-Newton system obtained by Buchert & Ehlers. The procedure is applied to two particular solutions given generic initial conditions. In this approach, the continuity equation yields a relation between the over-density and peculiar-velocity fields that automatically satisfies Euler's equation because the orbits are derived from the Lagrange-Newton system. This scheme generalizes some results obtained by Nusser et al. (1991) in the context of the Zel'dovich approximation. As opposed to several other reconstruction schemes, in this approach it is not necessary to truncate the expansion of the Jacobian given by the continuity equation in order to calculate a first- or second-order expression for the density field. In these previous schemes, the density contrast given by (a) the continuity equation and (b) Euler's equation are mutually incompatible. This inconsistency arises as a consequence of an improper handling of Lagrangian and Eulerian coordinates in the analysis. Here, we take into account the fact that an exact calculation of the density is feasible in the Lagrangian picture and therefore an accurate and consistent description is obtained.

Mikel Susperregi; Thomas Buchert

1997-08-04T23:59:59.000Z

434

Characterization of Vertical Velocity and Drop Size Distribution Parameters in Widespread Precipitation at ARM Facilities  

SciTech Connect (OSTI)

Extended, high-resolution measurements of vertical air motion and median volume drop diameter D0 in widespread precipitation from three diverse Atmospheric Radiation Measurement Program (ARM) locations [Lamont, Oklahoma, Southern Great Plains site (SGP); Niamey, Niger; and Black Forest, Germany] are presented. The analysis indicates a weak (0-10 cm{sup -1}) downward air motion beneath the melting layer for all three regions, a magnitude that is to within the typical uncertainty of the retrieval methods. On average, the hourly estimated standard deviation of the vertical air motion is 0.25 m s{sup -1} with no pronounced vertical structure. Profiles of D0 vary according to region and rainfall rate. The standard deviation of 1-min-averaged D0 profiles for isolated rainfall rate intervals is 0.3-0.4 mm. Additional insights into the form of the raindrop size distribution are provided using available dual-frequency Doppler velocity observations at SGP. The analysis suggests that gamma functions better explain paired velocity observations and radar retrievals for the Oklahoma dataset. This study will be useful in assessing uncertainties introduced in the measurement of precipitation parameters from ground-based and spaceborne remote sensors that are due to small-scale variability.

Giangrande S. E.; Luke, E. P.; Kollias, P.

2012-02-01T23:59:59.000Z

435

Real-time planar flow velocity measurements using an optical flow algorithm implemented on GPU  

E-Print Network [OSTI]

This paper presents a high speed implementation of an optical flow algorithm which computes planar velocity fields in an experimental flow. Real-time computation of the flow velocity field allows the experimentalist to have instantaneous access to quantitative features of the flow. This can be very useful in many situations: fast evaluation of the performances and characteristics of a new setup, design optimization, easier and faster parametric studies, etc. It can also be a valuable measurement tool for closed-loop flow control experiments where fast estimation of the state of the flow is needed. The algorithm is implemented on a Graphics Processing Unit (GPU). The accuracy of the computation is shown. Computation speed and scalability are highlighted along with guidelines for further improvements. The system architecture is flexible, scalable and can be adapted on the fly in order to process higher resolutions or achieve higher precision. The set-up is applied on a Backward-Facing Step (BFS) flow in a hydro...

Gautier, N

2013-01-01T23:59:59.000Z

436

Effects of neutral interactions on velocity-shear-driven plasma waves  

SciTech Connect (OSTI)

In a laboratory experiment, we demonstrate the substantial effects that collisions between charged and neutral particles have on low-frequency (?{sub i}????????{sub e}) shear-driven electrostatic lower hybrid waves in a plasma. We establish a strong (up to 2.5?kV/m) highly localized electric field with a length scale shorter than the ion gyroradius, so that the ions in the plasma, unlike the electrons, do not develop the full E?×?B drift velocity. The resulting shear in the particle velocities initiates the electron-ion hybrid (EIH) instability, and we observe the formation of strong waves in the vicinity of the shear with variations in plasma densities of 10% or greater. Our experimental configuration allows us to vary the neutral background density by more than a factor of two while holding the charged particle density effectively constant. Not surprisingly, increasing the neutral density decreases the growth rate/saturation amplitude of the waves and increases the threshold electric field necessary for wave formation, but the presence of neutrals affects the dominant wave frequency as well. We show that a 50% increase in the neutral density decreases the wave frequency by 20% while also suppressing the electric field dependence of the frequency that is observed when fewer neutrals are present. The majority of these effects, as well as the values of the frequencies we observe, closely match the predictions of previously developed linear EIH instability theory, for which we present the results of a numerical solution.

Enloe, C. L. [Physics Department, US Air Force Academy, Colorado Springs, Colorado 80840 (United States); Tejero, E. M.; Amatucci, W. E.; Crabtree, C.; Ganguli, G. [Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375 (United States); Sotnikov, V. [Sensors Directorate, Air Force Research Laboratory, Dayton, Ohio 45433 (United States)

2014-06-15T23:59:59.000Z

437

Holographic and time-resolving ability of pulse-pair two-dimensional velocity interferometry  

SciTech Connect (OSTI)

Previous velocity interferometers used at research laboratories for shock physics experiments measured target motion at a point or many points on a line on the target. Recently, a two-dimensional (2d) version (2d-velocity interferometer system for any reflector) has been demonstrated using a pair of ultrashort (3 ps) pulses for illumination, separated by 268 ps. We have discovered new abilities for this instrument, by treating the complex output image as a hologram. For data taken in an out of focus configuration, we can Fourier process to bring narrow features such as cracks into sharp focus, which are otherwise completely blurred. This solves a practical problem when using high numerical aperture optics having narrow depth of field to observe moving surface features such as cracks. Furthermore, theory predicts that the target appearance (position and reflectivity) at two separate moments in time are recorded by the main and conjugate images of the same hologram, and are partially separable during analysis for narrow features. Hence, for the cracks we bring into refocus, we can make a two-frame movie with a subnanosecond frame period. Longer and shorter frame periods are possible with different interferometer delays. Since the megapixel optical detectors we use have superior spatial resolution over electronic beam based framing cameras, this technology could be of great use in studying microscopic three-dimensional-behavior of targets at ultrafast times scales. Demonstrations on shocked silicon are shown.

Erskine, David J., E-mail: erskine1@llnl.gov; Smith, R. F.; Celliers, P. M.; Collins, G. W. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Bolme, C. A. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Ali, S. J. [Department of Chemistry, University of California, Berkeley, California 94720 (United States)

2014-06-15T23:59:59.000Z

438

Kr II and Xe II axial velocity distribution functions in a cross-field ion source  

SciTech Connect (OSTI)

Laser induced fluorescence measurements were carried out in a cross-field ion source to examine the behaviour of the axial ion velocity distribution functions (VDFs) in the expanding plasma. In the present paper, we focus on the axial VDFs of Kr II and Xe II ions. We examine the contourplots in a 1D-phase space (x,v{sub x}) representation in front of the exhaust channel and along the centerline of the ion source. The main ion beam, whose momentum corresponds to the ions that are accelerated through the whole potential drop, is observed. A secondary structure reveals the ions coming from the opposite side of the channel. We show that the formation of the neutralized ion flow is governed by the annular geometry. The assumption of a collisionless shock or a double layer due to supersonic beam interaction is not necessary. A non-negligible fraction of slow ions originates in local ionization or charge-exchange collision events between ions of the expanding plasma and atoms of the background residual gas. Slow ions that are produced near the centerline in the vicinity of the exit plane are accelerated toward the source body with a negative velocity leading to a high sputtering of front face. On the contrary, the ions that are produced in the vicinity of the channel exit plane are partially accelerated by the extended electric field.

Lejeune, A.; Bourgeois, G.; Mazouffre, S. [ICARE, CNRS, 1C Avenue de la Recherche Scientifique, 45071 Orlans Cedex 2 (France)

2012-07-15T23:59:59.000Z

439

Investigation of the Moessbauer Spectrum Quality as a Dependence on the Frequency of the Velocity Signal  

SciTech Connect (OSTI)

This paper is focused on a quality characterizing the Moessbauer spectra measured for various frequencies of the velocity signal. Standard electromechanical double-loudspeaker drive and digital PID velocity controller were used for calibration spectra measurement in the frequency interval from 4 up to 100 Hz. Several parameters were evaluated for recommendation of the suitable velocity signal frequency.

Pechousek, J. [Centre for Nanomaterial Research, Faculty of Science, Palacky University, Slechtitelu 11, 783 71, Olomouc (Czech Republic); Department of Experimental Physics, Faculty of Science, Palacky University, 17, listopadu 1192/12, 771 46, Olomouc (Czech Republic); Prochazka, R.; Cuda, J.; Frydrych, J.; Jancik, D. [Centre for Nanomaterial Research, Faculty of Science, Palacky University, Slechtitelu 11, 783 71, Olomouc (Czech Republic)

2010-07-13T23:59:59.000Z

440

Nested Velocity Feedback Control -1 Presented at CS 2007 Dr Richard Mitchell 2007  

E-Print Network [OSTI]

Nested Velocity Feedback Control - 1 Presented at CS 2007 © Dr Richard Mitchell 2007 Nested tolerant to changes in the plant under control #12;Nested Velocity Feedback Control - 2 Presented at CS path #12;Nested Velocity Feedback Control - 3 Presented at CS 2007 © Dr Richard Mitchell 2007 Cherry

Mitchell, Richard

Note: This page contains sample records for the topic "duct high velocity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

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

E-Print Network [OSTI]

2700 (Sulzer Metco, Westbury, NY) and the Praxair-TafaJP-5000 (Praxair Surface Technolo- gies, Indianapolis, IN)),pro- cessing using a Praxair-TAFA JP-5000 HVOF thermal spray

Li, Mingheng; Christofides, Panagiotis D.

2009-01-01T23:59:59.000Z

442

Measurement and modelling of high-resolution flow-velocity data under simulated rainfall on a  

E-Print Network [OSTI]

solves the Saint- Venant equations in 2D, MAHLERAN uses a 1D kinematic wave in the slope direction 0022 in revised form 5 July 2007; accepted 23 July 2007 KEYWORDS Rainfall-simulation; Water erosion; Erosion algorithm that is close in principle to the diffusion-wave equation in 2D. The Darcy­ Weisbach friction

443

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

E-Print Network [OSTI]

Size Distribution in Aerosol Processes with Simulta- neous Reaction, Nucleation, Condensation and Coagulation,

Li, Mingheng; Christofides, Panagiotis D.

2009-01-01T23:59:59.000Z

444

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

E-Print Network [OSTI]

vs. Fuzzy Logic: Simple Tools to Predict and Control Complexfuzzy logic (Ref 73, 74). For the HVOF thermal spray process, a feedback control

Li, Mingheng; Christofides, Panagiotis D.

2009-01-01T23:59:59.000Z

445

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

E-Print Network [OSTI]

Spray Technology Volume 18(5-6) Mid-December 2009—765 Oxygenoxygen and fuel are available, a previously developed approach (Ref 11) can Journal of Thermal Spray TechnologyTechnology Peer Reviewed Substrate properties Gas mass flow rate Fuel/oxygen

Li, Mingheng; Christofides, Panagiotis D.

2009-01-01T23:59:59.000Z

446

The effect of rainfall on the velocity distribution in shallow channel flow  

E-Print Network [OSTI]

, gave the following equation for uniform two-dimensional open channel f low v v max ~2. Iog y Ve~~ in which v is the velocity at any distance, y, above the channel bed, v Is the maximum velocity, g is the acceleration of gravity, d is the Illa X... piezometer located at the same longi- tudinal position along the flume at the tip of the ve'locity probe. The velocity coefficient of the total head probe was obtained by two methods. 29 One method was determining the velocity by observing the time...

Glass, Larry Joe

1965-01-01T23:59:59.000Z

447

Validation of velocity map imaging conditions over larger areas  

SciTech Connect (OSTI)

We have established through simulations and experiments the area over which Velocity Map Imaging (VMI) conditions prevail. We designed a VMI setup in which we can vary the ionization position perpendicular to the center axis of the time-of-flight spectrometer. We show that weak extraction conditions are far superior over standard three-plate setups if the aim is to increase the ionization volume without distorting VMI conditions. This is important for a number of crossed molecular beam experiments that already utilize weak extraction conditions, but to a greater extent for surface studies where fragments are desorbed or scattered off a surface in all directions. Our results on the dissociation of NO{sub 2} at 226 nm show that ionization of the fragments can occur up to {+-}5.5 mm away from the center axis of the time-of-flight spectrometer without affecting resolution or arrival position.

Reid, Mike; Koehler, Sven P. K. [School of Chemistry, University of Manchester, M13 9PL Manchester (United Kingdom); Photon Science Institute, University of Manchester, M13 9PL Manchester (United Kingdom); Dalton Cumbrian Facility, University of Manchester, Moor Row, CA24 3HA Whitehaven (United Kingdom)

2013-04-15T23:59:59.000Z

448

Acoustic velocity measurements in materials using a regenerative method  

DOE Patents [OSTI]

Acoustic energy is propagated through earth material between an electro-acoustic generator and a receiver which converts the received acoustic energy into electrical signals. A closed loop is formed by a variable gain amplifier system connected between the receiver and the generator. The gain of the amplifier system is increased until sustained oscillations are produced in the closed loop. The frequency of the oscillations is measured as an indication of the acoustic propagation velocity through the earth material. The amplifier gain is measured as an indication of the acoustic attenuation through the earth materials. The method is also applicable to the non-destructive testing of structural materials, such as steel, aluminum and concrete.

Laine, Edwin F. (Alamo, CA)

1986-01-01T23:59:59.000Z

449

Acoustic-velocity measurements in materials using a regenerative method  

DOE Patents [OSTI]

Acoustic energy is propatated through earth material between an electro-acoustic generator and a receiver which converts the received acoustic energy into electrical signals. A closed loop is formed by a variable gain amplifier system connected between the receiver and the generator. The gain of the amplifier system is increased until sustained oscillations are produced in the closed loop. The frequency of the oscillations is measured as an indication of the acoustic propagation velocity through the earth material. The amplifier gain is measured as an indication of the acoustic attenuation through the earth materials. The method is also applicable to the non-destructive testing of structural materials, such as steel, aluminum and concrete.

Laine, E.F.

1982-09-30T23:59:59.000Z

450

Continued Evaluation of the Pulse-Echo Ultrasonic Instrument for Critical Velocity Determination during Hanford Tank Waste Transfer Operations  

SciTech Connect (OSTI)

Laboratory (PNNL) conducted an extensive evaluation of the ability of three ultrasonic instruments to detect critical velocity for a broad range of simulated Hanford nuclear waste streams containing particles with mean particle sizes of >50 microns. Evaluations were perform using the pipe loop at the Process Development Laboratory – East (PDL-E) at PNNL that was designed and built to evaluate the pipeline plugging issue during slurry transfer operations at the Hanford Waste Treatment Plant. In 2011 the ability of the ultrasonic PulseEcho system to detect critical velocity continued to be evaluated using the PDL-E flow loop and new simulants containing high-density particles with a mean particle size of < 15 microns. The PDL-E flow loop was modified for the 2011 testing to include a new test section that contained 5-MHz and 10-MHz ultrasonic transducers non-invasively mounted to schedule 40 pipe. The test section also contained reference instrumentation to facilitate direct comparison of the real-time PulseEcho transducer responses with experimentally observed critical velocities. This paper presents the results from the 2011 PulseEcho evaluation using a variety of simulated Hanford nuclear waste streams that were selected to encompass the expected high-level waste feed properties.

Denslow, Kayte M.; Bontha, Jagannadha R.; Adkins, Harold E.; Jenks, Jeromy WJ; Burns, Carolyn A.; Schonewill, Philip P.; Hopkins, Derek F.; Thien, Michael G.; Wooley, Theodore A.

2012-04-01T23:59:59.000Z

451

Horizontal-Velocity and Variance Measurements in the Stable Boundary Layer Using Doppler Lidar: Sensitivity to Averaging Procedures  

SciTech Connect (OSTI)

Quantitative data on turbulence variables aloft--above the region of the atmosphere conveniently measured from towers--has been an important but difficult measurement need for advancing understanding and modeling of the stable boundary layer (SBL). Vertical profiles of streamwise velocity variances obtained from NOAA’s High Resolution Doppler Lidar (HRDL), which have been shown to be numerically equivalent to turbulence kinetic energy (TKE) for stable conditions, are a measure of the turbulence in the SBL. In the present study, the mean horizontal wind component U and variance ?u2 were computed from HRDL measurements of the line-of-sight (LOS) velocity using a technique described in Banta, et al. (2002). The technique was tested on datasets obtained during the Lamar Low-Level Jet Project (LLLJP) carried out in early September 2003, near the town of Lamar in southeastern Colorado. This paper compares U with mean wind speed obtained from sodar and sonic anemometer measurements. It then describes several series of averaging tests that produced the best correlation between TKE calculated from sonic anemometer data at several tower levels and lidar measurements of horizontal velocity variance ?u2. The results show high correlation (0.71-0.97) of the mean U and average wind speed measured by sodar and in-situ instruments, independent of sampling strategies and averaging procedures. Comparison of estimates of variance, on the other hand, proved sensitive to both the spatial and temporal averaging techniques.

Pichugina, Yelena L.; Banta, Robert M.; Kelley, Neil D.; Jonkman, Bonnie J.; Tucker, Sara C.; Newsom, Rob K.; Brewer, W. A.

2008-08-01T23:59:59.000Z

452

Nonlinear Landau damping and formation of Bernstein-Greene-Kruskal structures for plasmas with q-nonextensive velocity distributions  

SciTech Connect (OSTI)

In the past, long-time evolution of an initial perturbation in collisionless Maxwellian plasma (q = 1) has been simulated numerically. The controversy over the nonlinear fate of such electrostatic perturbations was resolved by Manfredi [Phys. Rev. Lett. 79, 2815-2818 (1997)] using long-time simulations up to t=1600{omega}{sub p}{sup -1}. The oscillations were found to continue indefinitely leading to Bernstein-Greene-Kruskal (BGK)-like phase-space vortices (from here on referred as 'BGK structures'). Using a newly developed, high resolution 1D Vlasov-Poisson solver based on piecewise-parabolic method (PPM) advection scheme, we investigate the nonlinear Landau damping in 1D plasma described by toy q-distributions for long times, up to t=3000{omega}{sub p}{sup -1}. We show that BGK structures are found only for a certain range of q-values around q = 1. Beyond this window, for the generic parameters, no BGK structures were observed. We observe that for values of q<1 where velocity distributions have long tails, strong Landau damping inhibits the formation of BGK structures. On the other hand, for q>1 where distribution has a sharp fall in velocity, the formation of BGK structures is rendered difficult due to high wave number damping imposed by the steep velocity profile, which had not been previously reported. Wherever relevant, we compare our results with past work.

Raghunathan, M. [Indian Institute of Science Education and Research (IISER), Pune 411021 (India); Ganesh, R. [Institute for Plasma Research, Gandhinagar 382428 (India)

2013-03-15T23:59:59.000Z

453

Distributions of velocity and turbulence in a parallel flow along an asymmetric rod bundle  

SciTech Connect (OSTI)

An experimental investigation was performed to obtain detailed information on the velocity and turbulence distributions in a parallel turbulent flow through an asymmetric rod bundle. The rod bundle consisted of four parallel rods arranged asymmetrically in a rectangular channel. The pitch-to-diameter (P/D) ratio of the rods was P/D = 1.072. Experimental results were obtained in two wall subchannels with wall-to-diameter (W/D) ratios of W/D = 1.096 and 1.048, respectively. The experimental results showed high anisotropy of the momentum transport, particularly in the gaps of the rod bundle. Comparisons between the measured wall shear stresses and data computed by the VELASCO code show considerable differences, particularly for the wall subchannel with W/D = 1.048.

Rehme, K.

1982-10-01T23:59:59.000Z

454

Optical pin apparatus for measuring the arrival time and velocity of shock waves and particles  

DOE Patents [OSTI]

An apparatus for the detection of the arrival and for the determination of the velocity of disturbances such as shock-wave fronts and/or projectiles. Optical pins using fluid-filled microballoons as the light source and an optical fiber as a link to a photodetector have been used to investigate shock-waves and projectiles. A microballoon filled with a noble gas is affixed to one end of a fiber-optic cable, and the other end of the cable is attached to a high-speed streak camera. As the shock-front or projectile compresses the microballoon, the gas inside is heated and compressed producing a bright flash of light. The flash of light is transmitted via the optic cable to the streak camera where it is recorded. One image-converter streak camera is capable of recording information from more than 100 microballoon-cable combinations simultaneously.

Benjamin, R.F.

1983-10-18T23:59:59.000Z

455

Particle in cell simulations of Buneman instability of a current-driven plasma with q-nonextensive electron velocity distribution  

SciTech Connect (OSTI)

The nonlinear evolution of low frequency Buneman instability in an unmagnetized current-driven plasma with q-nonextensive electron velocity distribution is investigated using particle in cell simulation. Simulation results show that the generation of electron phase space holes and the counter-streaming current induced in the plasma strongly depend on the q-parameter. It is found that by increasing the nonextensive parameter, the distribution of electron density becomes highly peaked. This density steepening or grating-like pattern occurs at the saturation time. In addition, a generalized dispersion relation is obtained using the kinetic theory. Analysis of the dispersion relation and the temporal evolution of the electric field energy density reveal that the growth rate of instability increases by increasing the q-parameter. Finally, the results of Maxwellian and q-nonextensive velocity distributions have been compared and discussed.

Niknam, A. R., E-mail: a-niknam@sbu.ac.ir; Roozbahani, H.; Komaizi, D. [Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Tehran (Iran, Islamic Republic of); Hashemzadeh, M. [Faculty of Physics, Shahrood University, Shahrood (Iran, Islamic Republic of)

2014-09-15T23:59:59.000Z

456

Radiation Hydrodynamics Test Problems with Linear Velocity Profiles  

SciTech Connect (OSTI)

As an extension of the works of Coggeshall and Ramsey, a class of analytic solutions to the radiation hydrodynamics equations is derived for code verification purposes. These solutions are valid under assumptions including diffusive radiation transport, a polytropic gas equation of state, constant conductivity, separable flow velocity proportional to the curvilinear radial coordinate, and divergence-free heat flux. In accordance with these assumptions, the derived solution class is mathematically invariant with respect to the presence of radiative heat conduction, and thus represents a solution to the compressible flow (Euler) equations with or without conduction terms included. With this solution class, a quantitative code verification study (using spatial convergence rates) is performed for the cell-centered, finite volume, Eulerian compressible flow code xRAGE developed at Los Alamos National Laboratory. Simulation results show near second order spatial convergence in all physical variables when using the hydrodynamics solver only, consistent with that solver's underlying order of accuracy. However, contrary to the mathematical properties of the solution class, when heat conduction algorithms are enabled the calculation does not converge to the analytic solution.

Hendon, Raymond C. [Los Alamos National Laboratory; Ramsey, Scott D. [Los Alamos National Laboratory

2012-08-22T23:59:59.000Z

457

Impact of boundaries on velocity profiles in bubble rafts  

E-Print Network [OSTI]

Under conditions of sufficiently slow flow, foams, colloids, granular matter, and various pastes have been observed to exhibit shear localization, i.e. regions of flow coexisting with regions of solid-like behavior. The details of such shear localization can vary depending on the system being studied. A number of the systems of interest are confined so as to be quasi-two dimensional, and an important issue in these systems is the role of the confining boundaries. For foams, three basic systems have been studied with very different boundary conditions: Hele-Shaw cells (bubbles confined between two solid plates); bubble rafts (a single layer of bubbles freely floating on a surface of water); and confined bubble rafts (bubbles confined between the surface of water below and a glass plate on top). Often, it is assumed that the impact of the boundaries is not significant in the ``quasi-static limit'', i.e. when externally imposed rates of strain are sufficiently smaller than internal kinematic relaxation times. In this paper, we directly test this assumption for rates of strain ranging from $10^{-3}$ to $10^{-2} {\\rm s^{-1}}$. This corresponds to the quoted quasi-static limit in a number of previous experiments. It is found that the top plate dramatically alters both the velocity profile and the distribution of nonlinear rearrangements, even at these slow rates of strain.

Yuhong Wang; Kapilanjan Krishan; Michael Dennin

2006-01-31T23:59:59.000Z

458

Design of a hypersonic waterjet apparatus driven by high explosives  

SciTech Connect (OSTI)

The design and construction of a hypersonic waterjet apparatus is described. Jet velocities from 0.5 to 5 km/s have been achieved using a high explosive charge. Images are obtained in situ on various target substrates using a high-speed framing camera. Experimental results are shown for the impact of high velocity waterjets on propellants and high explosive samples. By observing the impact of the waterjet at a wide range of velocities a safety threshold can be determined where no reaction takes place.

Weeks, Brandon L.; Klosterman, John; Worsey, Paul N.

2001-08-01T23:59:59.000Z

459

A numerical study of geometry dependent errors in velocity, temperature, and density measurements from single grid planar retarding potential analyzers  

SciTech Connect (OSTI)

Planar retarding potential analyzers (RPAs) have been utilized numerous times on high profile missions such as the Communications/Navigation Outage Forecast System and the Defense Meteorological Satellite Program to measure plasma composition, temperature, density, and the velocity component perpendicular to the plane of the instrument aperture. These instruments use biased grids to approximate ideal biased planes. These grids introduce perturbations in the electric potential distribution inside the instrument and when unaccounted for cause errors in the measured plasma parameters. Traditionally, the grids utilized in RPAs have been made of fine wires woven into a mesh. Previous studies on the errors caused by grids in RPAs have approximated woven grids with a truly flat grid. Using a commercial ion optics software package, errors in inferred parameters caused by both woven and flat grids are examined. A flat grid geometry shows the smallest temperature and density errors, while the double thick flat grid displays minimal errors for velocities over the temperature and velocity range used. Wire thickness along the dominant flow direction is found to be a critical design parameter in regard to errors in all three inferred plasma parameters. The results shown for each case provide valuable design guidelines for future RPA development.

Davidson, R. L.; Earle, G. D.; Heelis, R. A. [William B. Hanson Center for Space Sciences, University of Texas at Dallas, 800 W. Campbell Road, WT15, Richardson, Texas 75080 (United States); Klenzing, J. H. [Space Weather Laboratory/Code 674, Goddard Space Flight Center, Greenbelt, Maryland 20771 (United States)

2010-08-15T23:59:59.000Z

460

Recommended Tritium Oxide Deposition Velocity For Use In Savannah River Site Safety Analyses  

SciTech Connect (OSTI)

This report documents the results of examining the deposition velocity of water to forests, the residence time of HTO in forests, and the relation between deposition velocity and residence time with specific consideration given to the topography and experimental work performed at SRS. A simple mechanistic model is used to obtain plausible deposition velocity and residence time values where experimental data are not available and recommendations are made for practical application in a safety analysis model.

Lee, P. L.; Murphy, C. E.; Viner, B. J.; Hunter, C. H.

2012-07-31T23:59:59.000Z

Note: This page contains sample records for the topic "duct high velocity" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

CALIBRATING STELLAR VELOCITY DISPERSIONS BASED ON SPATIALLY RESOLVED H-BAND SPECTRA FOR IMPROVING THE M{sub BH}-{sigma}{sub *} RELATION  

SciTech Connect (OSTI)

To calibrate stellar velocity dispersion measurements from optical and near-IR stellar lines, and to improve the black hole mass (M{sub BH})-stellar velocity dispersion ({sigma}{sub *}) relation, we measure {sigma}{sub *} based on high-quality H-band spectra for a sample of 31 nearby galaxies, for which dynamical M{sub BH} is available in the literature. By comparing velocity dispersions measured from stellar lines in the H-band with those measured from optical stellar lines, we find no significant difference, suggesting that optical and near-IR stellar lines represent the same kinematics and that dust effect is negligible for early-type galaxies. Based on the spatially resolved rotation and velocity dispersion measurements along the major axis of each galaxy, we find that a rotating stellar disk is present for 80% of galaxies in the sample. For galaxies with a rotation component, {sigma}{sub *} measured from a single aperture spectrum can vary by up to {approx}20%, depending on the size of the adopted extraction aperture. To correct for the rotational broadening, we derive luminosity-weighted {sigma}{sub *} within the effective radius of each galaxy, providing uniformly measured velocity dispersions to improve the M{sub BH}-{sigma}{sub *} relation.

Kang, Wol-Rang; Woo, Jong-Hak; Park, Daeseong [Astronomy Program, Department of Physics and Astronomy, Seoul National University, 1 Gwanak-ro Gwanak-gu, Seoul, 151-742 (Korea, Republic of)] [Astronomy Program, Department of Physics and Astronomy, Seoul National University, 1 Gwanak-ro Gwanak-gu, Seoul, 151-742 (Korea, Republic of); Schulze, Andreas [Kavli Institute for Astronomy and Astrophysics, Peking University, 100871 Beijing (China)] [Kavli Institute for Astronomy and Astrophysics, Peking University, 100871 Beijing (China); Riechers, Dominik A. [Astronomy Department, Cornell University, 220 Space Science Building, Ithaca, NY 14853 (United States)] [Astronomy Department, Cornell University, 220 Space Science Building, Ithaca, NY 14853 (United States); Kim, Sang Chul [Korea Astronomy and Space Science Institute, Daejeon 305-348 (Korea, Republic of)] [Korea Astronomy and Space Science Institute, Daejeon 305-348 (Korea, Republic of); Smolcic, Vernesa, E-mail: woo@astro.snu.ac.kr [Physics Department, University of Zagreb, Bijenicka cesta 32, 10002 Zagreb (Croatia)] [Physics Department, University of Zagreb, Bijenicka cesta 32, 10002 Zagreb (Croatia)

2013-04-10T23:59:59.000Z

462

asymmetric m-b velocity: Topics by E-print Network  

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

Consistent with Asymmetric M-B Velocity Distributions-Implications on Direct Dark Matter Searches General Relativity & Quantum Cosmology (arXiv) Summary: In the present paper...

463

E-Print Network 3.0 - air stream velocities Sample Search Results  

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

and Environment GIS Lab Collection: Engineering 11 1 Copyright 1997 by ASME 1997 ASME Fluids Engineering Division Summer Meeting Summary: or structure velocity u Streamwise...

464

E-Print Network 3.0 - acoustic particle velocity Sample Search...  

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

of Mathematics, Purdue University Collection: Mathematics 44 AIAA 2001-2961 The Rijke Tube Revisited via Laboratory Summary: product of acoustic velocity and pressure, known as...

465

AN ASSESSMENT OF THE ACCURACY OF MAGENTIC RESONANCE PHASE VELOCITY MAPPING IN TURBULENT FLOW THROUGH ORIFICES.  

E-Print Network [OSTI]

?? Magnetic resonance phase velocity mapping (MRPVM) is an established clinical technique to measure blood flow. The acquired information can be used to diagnose a… (more)

Pidaparthi, Sahitya

2011-01-01T23:59:59.000Z

466

Test Loop Demonstration and Evaluation of Slurry Transfer Line Critical Velocity Measurement Instruments  

SciTech Connect (OSTI)

This report presents the results of the evaluation of three ultrasonic sensors for detecting critical velocity during slurry transfer between the Hanford tank farms and the WTP.

Bontha, Jagannadha R.; Jenks, Jeromy WJ; Morgen, Gerald P.; Peters, Timothy J.; Wilcox, Wayne A.; Adkins, Harold E.; Burns, Carolyn A.; Greenwood, Margaret S.; MacFarlan, Paul J.; Denslow, Kayte M.; Schonewill, Philip P.; Blanchard, Jeremy; Baer, Ellen BK

2010-07-31T23:59:59.000Z

467

E-Print Network 3.0 - ambient transverse velocity Sample Search...  

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

the Radially Anisotropic Crustal Velocity Structure of NW Canada with Ambient-Noise Tomography M. E. Daigle1; C... -component records and Love waves on the transverse components....

468

E-Print Network 3.0 - air velocity temperature Sample Search...  

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

and Medicine ; Environmental Sciences and Ecology 66 Water Modeling of Steel Flow, Air Entrainment and Filtration Summary: . In general, a certain minimum velocity has to be...

469

Horizontal Velocity and Variance Measurements in the Stable Boundary Layer Using Doppler Lidar: Sensitivity to Averaging Procedures  

SciTech Connect (OSTI)

Quantitative data on turbulence variables aloft--above the region of the atmosphere conveniently measured from towers--have been an important but difficult measurement need for advancing understanding and modeling of the stable boundary layer (SBL). Vertical profiles of streamwise velocity variances obtained from NOAA's high-resolution Doppler lidar (HRDL), which have been shown to be approximately equal to turbulence kinetic energy (TKE) for stable conditions, are a measure of the turbulence in the SBL. In the present study, the mean horizontal wind component U and variance {sigma}2u were computed from HRDL measurements of the line-of-sight (LOS) velocity using a method described by Banta et al., which uses an elevation (vertical slice) scanning technique. The method was tested on datasets obtained during the Lamar Low-Level Jet Project (LLLJP) carried out in early September 2003, near the town of Lamar in southeastern Colorado. This paper compares U with mean wind speed obtained from sodar and sonic anemometer measurements. The results for the mean U and mean wind speed measured by sodar and in situ instruments for all nights of LLLJP show high correlation (0.71-0.97), independent of sampling strategies and averaging procedures, and correlation coefficients consistently >0.9 for four high-wind nights, when the low-level jet speeds exceeded 15 m s{sup -1} at some time during the night. Comparison of estimates of variance, on the other hand, proved sensitive to both the spatial and temporal averaging parameters. Several series of averaging tests are described, to find the best correlation between TKE calculated from sonic anemometer data at several tower levels and lidar measurements of horizontal-velocity variance {sigma}{sup 2}{sub u}. Because of the nonstationarity of the SBL data, the best results were obtained when the velocity data were first averaged over intervals of 1 min, and then further averaged over 3-15 consecutive 1-min intervals, with best results for the 10- and 15-min averaging periods. For these cases, correlation coefficients exceeded 0.9. As a part of the analysis, Eulerian integral time scales ({tau}) were estimated for the four high-wind nights. Time series of {tau} through each night indicated erratic behavior consistent with the nonstationarity. Histograms of {tau} showed a mode at 4-5 s, but frequent occurrences of larger {tau} values, mostly between 10 and 100 s.

Pichugina, Y. L.; Banta, R. M.; Kelley, N. D.; Jonkman, B. J.; Tucker, S. C.; Newsom, R. K.; Brewer, W. A.

2008-08-01T23:59:59.000Z

470

Deeply-scaled GaN high electron mobility transistors for RF applications  

E-Print Network [OSTI]

Due to the unique combination of large critical breakdown field and high electron velocity, GaN-based high electron mobility transistors (HEMTs) have great potential for next generation high power RF amplifiers. The ...

Lee, Dong Seup

2014-01-01T23:59:59.000Z

471

A Virtual Velocity Attractor, Harmonic Potential Approach for Joint planning and control of a UAV  

E-Print Network [OSTI]

A Virtual Velocity Attractor, Harmonic Potential Approach for Joint planning and control of a UAV vehicles (UAVs). The method indirectly controls the trajectory of a UAV by regulating its velocity using planner into a well-behaved control signal that can be fed to the actuator of the UAV. I. Introduction

Masoud, Ahmad A.